Patent Application
20210410084
As Vehicle-to-everything (V2X) applications make significant progress, transmission of short messages about vehicles' own status data for basic safety may need to be extended with transmission of larger messages containing raw sensor data, vehicles' intention data, coordination and confirmation of future maneuver, etc. For these advanced applications, the expected requirements to meet the needed data rate, latency, reliability, communication range and speed are made more stringent.
For enhanced V2X (eV2X) services, 3GPP has identified 25 use cases and the related requirements in TR 22.886 (see 3GPP TR 22.886 Study on enhancement of 3GPP Support for 5G V2X Services, Release 16, V16.0.0). The normative requirements are specified in TS 22.186 with the use cases categorized into four use case groups: vehicles platooning, advanced driving, extended sensors and remote driving (see 3GPP TS 22.186 Enhancement of 3GPP support for V2X scenarios (Stage 1), Release 16, V16.0.0). The detailed description of performance requirements for each use case group are specified in TS 22.186, which guides the New Radio (NR) V2X specification.
Methods and systems for Sidelink Transmit Power Control are disclosed. Example methods and systems may include but are not limited to path loss estimation for sidelink including Reference Signals (RS) for path loss measurement and path loss estimation for proximity based transmit power control, open-loop transmit power control on sidelink including synchronization, discovery, and broadcast, as well as closed-loop transmit power control on sidelink including two-way transmit power control on sidelink for unicast and two-way transmit power control on sidelink for groupcast or multicast. Methods and systems for transmit power sharing are disclosed. Example methods and systems may include but are not limited to transmit power sharing between uplink and sidelink and transmit power sharing between sidelinks.
This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. Furthermore, the claimed subject matter is not limited to limitations that solve any or all disadvantages noted in any part of this disclosure.
The following detailed description is better understood when read in conjunction with the appended drawings. For the purposes of illustration, examples are shown in the drawings; however, the subject matter is not limited to specific elements and instrumentalities disclosed. In the drawings:
The 3rd Generation Partnership Project (3GPP) develops technical standards for cellular telecommunications network technologies, including radio access, the core transport network, and service capabilities—including work on codecs, security, and quality of service. Recent radio access technology (RAT) standards include WCDMA (commonly referred as 3G), LTE (commonly referred as 4G), LTE-Advanced standards, and New Radio (NR), which is also referred to as “5G”. 3GPP NR standards development is expected to continue and include the definition of next generation radio access technology (new RAT), which is expected to include the provision of new flexible radio access below 7 GHz, and the provision of new ultra-mobile broadband radio access above 7 GHz. The flexible radio access is expected to consist of a new, non-backwards compatible radio access in new spectrum below 7 GHz, and it is expected to include different operating modes that may be multiplexed together in the same spectrum to address a broad set of 3GPP NR use cases with diverging requirements. The ultra-mobile broadband is expected to include cmWave and mmWave spectrum that will provide the opportunity for ultra-mobile broadband access for, e.g., indoor applications and hotspots. In particular, the ultra-mobile broadband is expected to share a common design framework with the flexible radio access below 7 GHz, with cmWave and mmWave specific design optimizations.
3GPP has identified a variety of use cases that NR is expected to support, resulting in a wide variety of user experience requirements for data rate, latency, and mobility. The use cases include the following general categories: enhanced mobile broadband (eMBB) ultra-reliable low-latency Communication (URLLC), massive machine type communications (mMTC), network operation (e.g., network slicing, routing, migration and interworking, energy savings), and enhanced vehicle-to-everything (eV2X) communications, which may include any of Vehicle-to-Vehicle Communication (V2V), Vehicle-to-Infrastructure Communication (V2I), Vehicle-to-Network Communication (V2N), Vehicle-to-Pedestrian Communication (V2P), and vehicle communications with other entities. Specific service and applications in these categories include, e.g., monitoring and sensor networks, device remote controlling, bi-directional remote controlling, personal cloud computing, video streaming, wireless cloud-based office, first responder connectivity, automotive ecall, disaster alerts, real-time gaming, multi-person video calls, autonomous driving, augmented reality, tactile internet, virtual reality, home automation, robotics, and aerial drones to name a few. All of these use cases and others are contemplated herein.
It will be appreciated that the concepts disclosed herein may be used with any number of WTRUs, base stations, networks, and/or network elements. Each of the WTRUs 102 may be any type of apparatus or device configured to operate and/or communicate in a wireless environment. In the example of
The communications system 100 may also include a base station 114a and a base station 114b. In the example of
TRPs 119a, 119b may be any type of device configured to wirelessly interface with at least one of the WTRU 102d, to facilitate access to one or more communication networks, such as the core network 106/107/109, the Internet 110, Network Services 113, and/or other networks 112. RSUs 120a and 120b may be any type of device configured to wirelessly interface with at least one of the WTRU 102e or 102f, to facilitate access to one or more communication networks, such as the core network 106/107/109, the Internet 110, other networks 112, and/or Network Services 113. By way of example, the base stations 114a, 114b may be a Base Transceiver Station (BTS), a Node-B, an eNode B, a Home Node B, a Home eNode B, a Next Generation Node-B (gNode B), a satellite, a site controller, an access point (AP), a wireless router, and the like.
The base station 114a may be part of the RAN 103/104/105, which may also include other base stations and/or network elements (not shown), such as a Base Station Controller (BSC), a Radio Network Controller (RNC), relay nodes, etc. Similarly, the base station 114b may be part of the RAN 103b/104b/105b, which may also include other base stations and/or network elements (not shown), such as a BSC, a RNC, relay nodes, etc. The base station 114a may be configured to transmit and/or receive wireless signals within a particular geographic region, which may be referred to as a cell (not shown). Similarly, the base station 114b may be configured to transmit and/or receive wired and/or wireless signals within a particular geographic region, which may be referred to as a cell (not shown). The cell may further be divided into cell sectors. For example, the cell associated with the base station 114a may be divided into three sectors. Thus, for example, the base station 114a may include three transceivers, e.g., one for each sector of the cell. The base station 114a may employ Multiple-Input Multiple Output (MIMO) technology and, therefore, may utilize multiple transceivers for each sector of the cell, for instance.
The base station 114a may communicate with one or more of the WTRUs 102a, 102b, 102c, and 102g over an air interface 115/116/117, which may be any suitable wireless communication link (e.g., Radio Frequency (RF), microwave, infrared (IR), ultraviolet (UV), visible light, cmWave, mmWave, etc.). The air interface 115/116/117 may be established using any suitable Radio Access Technology (RAT).
The base station 114b may communicate with one or more of the RRHs 118a and 118b, TRPs 119a and 119b, and/or RSUs 120a and 120b, over a wired or air interface 115b/116b/117b, which may be any suitable wired (e.g., cable, optical fiber, etc.) or wireless communication link (e.g., RF, microwave, IR, UV, visible light, cmWave, mmWave, etc.). The air interface 115b/116b/117b may be established using any suitable RAT.
The RRHs 118a, 118b, TRPs 119a, 119b and/or RSUs 120a, 120b, may communicate with one or more of the WTRUs 102c, 102d, 102e, 102f over an air interface 115c/116c/117c, which may be any suitable wireless communication link (e.g., RF, microwave, IR, ultraviolet UV, visible light, cmWave, mmWave, etc.) The air interface 115c/116c/117c may be established using any suitable RAT.
The WTRUs 102 may communicate with one another over a direct air interface 115d/116d/117d, such as Sidelink communication which may be any suitable wireless communication link (e.g., RF, microwave, IR, ultraviolet UV, visible light, cmWave, mmWave, etc.) The air interface 115d/116d/117d may be established using any suitable RAT.
The communications system 100 may be a multiple access system and may employ one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and the like. For example, the base station 114a in the RAN 103/104/105 and the WTRUs 102a, 102b, 102c, or RRHs 118a, 118b, TRPs 119a, 119b and/or RSUs 120a and 120b in the RAN 103b/104b/105b and the WTRUs 102c, 102d, 102e, and 102f, may implement a radio technology such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which may establish the air interface 115/116/117 and/or 115c/116c/117c respectively using Wideband CDMA (WCDMA). WCDMA may include communication protocols such as High-Speed Packet Access (HSPA) and/or Evolved HSPA (HSPA+). HSPA may include High-Speed Downlink Packet Access (HSDPA) and/or High-Speed Uplink Packet Access (HSUPA).
The base station 114a in the RAN 103/104/105 and the WTRUs 102a, 102b, 102c, and 102g, or RRHs 118a and 118b, TRPs 119a and 119b, and/or RSUs 120a and 120b in the RAN 103b/104b/105b and the WTRUs 102c, 102d, may implement a radio technology such as Evolved UMTS Terrestrial Radio Access (E-UTRA), which may establish the air interface 115/116/117 or 115c/116c/117c respectively using Long Term Evolution (LTE) and/or LTE-Advanced (LTE-A), for example. The air interface 115/116/117 or 115c/116c/117c may implement 3GPP NR technology. The LTE and LTE-A technology may include LTE D2D and/or V2X technologies and interfaces (such as Sidelink communications, etc.) Similarly, the 3GPP NR technology may include NR V2X technologies and interfaces (such as Sidelink communications, etc.)
The base station 114a in the RAN 103/104/105 and the WTRUs 102a, 102b, 102c, and 102g or RRHs 118a and 118b, TRPs 119a and 119b, and/or RSUs 120a and 120b in the RAN 103b/104b/105b and the WTRUs 102c, 102d, 102e, and 102f may implement radio technologies such as IEEE 802.16 (e.g., Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000, CDMA2000 1×, CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), Interim Standard 856 (IS-856), Global System for Mobile communications (GSM), Enhanced Data rates for GSM Evolution (EDGE), GSM EDGE (GERAN), and the like.
The base station 114c in
The RAN 103/104/105 and/or RAN 103b/104b/105b may be in communication with the core network 106/107/109, which may be any type of network configured to provide voice, data, messaging, authorization and authentication, applications, and/or Voice Over Internet Protocol (VoIP) services to one or more of the WTRUs 102. For example, the core network 106/107/109 may provide call control, billing services, mobile location-based services, pre-paid calling, Internet connectivity, packet data network connectivity, Ethernet connectivity, video distribution, etc., and/or perform high-level security functions, such as user authentication.
Although not shown in
The core network 106/107/109 may also serve as a gateway for the WTRUs 102 to access the PSTN 108, the Internet 110, and/or other networks 112. The PSTN 108 may include circuit-switched telephone networks that provide Plain Old Telephone Service (POTS). The Internet 110 may include a global system of interconnected computer networks and devices that use common communication protocols, such as the Transmission Control Protocol (TCP), User Datagram Protocol (UDP), and the internet protocol (IP) in the TCP/IP internet protocol suite. The other networks 112 may include wired or wireless communications networks owned and/or operated by other service providers. For example, the networks 112 may include any type of packet data network (e.g., an IEEE 802.3 Ethernet network) or another core network connected to one or more RANs, which may employ the same RAT as the RAN 103/104/105 and/or RAN 103b/104b/105b or a different RAT.
Some or all of the WTRUs 102a, 102b, 102c, 102d, 102e, and 102f in the communications system 100 may include multi-mode capabilities, e.g., the WTRUs 102a, 102b, 102c, 102d, 102e, and 102f may include multiple transceivers for communicating with different wireless networks over different wireless links. For example, the WTRU 102g shown in
Although not shown in
As shown in
The core network 106 shown in
The RNC 142a in the RAN 103 may be connected to the MSC 146 in the core network 106 via an IuCS interface. The MSC 146 may be connected to the MGW 144. The MSC 146 and the MGW 144 may provide the WTRUs 102a, 102b, and 102c with access to circuit-switched networks, such as the PSTN 108, to facilitate communications between the WTRUs 102a, 102b, and 102c, and traditional land-line communications devices.
The RNC 142a in the RAN 103 may also be connected to the SGSN 148 in the core network 106 via an IuPS interface. The SGSN 148 may be connected to the GGSN 150. The SGSN 148 and the GGSN 150 may provide the WTRUs 102a, 102b, and 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between and the WTRUs 102a, 102b, and 102c, and IP-enabled devices.
The core network 106 may also be connected to the other networks 112, which may include other wired or wireless networks that are owned and/or operated by other service providers.
As noted above, the RAN 104 may employ an E-UTRA radio technology to communicate with the WTRUs 102a, 102b, and 102c over the air interface 116. The RAN 104 may also be in communication with the core network 107.
The RAN 104 may include eNode-Bs 160a, 160b, and 160c, though it will be appreciated that the RAN 104 may include any number of eNode-Bs. The eNode-Bs 160a, 160b, and 160c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, and 102c over the air interface 116. For example, the eNode-Bs 160a, 160b, and 160c may implement MIMO technology. Thus, the eNode-B 160a, for example, may use multiple antennas to transmit wireless signals to, and receive wireless signals from, the WTRU 102a.
Each of the eNode-Bs 160a, 160b, and 160c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the uplink and/or downlink, and the like. As shown in
The core network 107 shown in
The MME 162 may be connected to each of the eNode-Bs 160a, 160b, and 160c in the RAN 104 via an S1 interface and may serve as a control node. For example, the MME 162 may be responsible for authenticating users of the WTRUs 102a, 102b, and 102c, bearer activation/deactivation, selecting a particular serving gateway during an initial attach of the WTRUs 102a, 102b, and 102c, and the like. The MME 162 may also provide a control plane function for switching between the RAN 104 and other RANs (not shown) that employ other radio technologies, such as GSM or WCDMA.
The serving gateway 164 may be connected to each of the eNode-Bs 160a, 160b, and 160c in the RAN 104 via the S1 interface. The serving gateway 164 may generally route and forward user data packets to/from the WTRUs 102a, 102b, and 102c. The serving gateway 164 may also perform other functions, such as anchoring user planes during inter-eNode B handovers, triggering paging when downlink data is available for the WTRUs 102a, 102b, and 102c, managing and storing contexts of the WTRUs 102a, 102b, and 102c, and the like.
The serving gateway 164 may also be connected to the PDN gateway 166, which may provide the WTRUs 102a, 102b, and 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c, and IP-enabled devices.
The core network 107 may facilitate communications with other networks. For example, the core network 107 may provide the WTRUs 102a, 102b, and 102c with access to circuit-switched networks, such as the PSTN 108, to facilitate communications between the WTRUs 102a, 102b, and 102c and traditional land-line communications devices. For example, the core network 107 may include, or may communicate with, an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that serves as an interface between the core network 107 and the PSTN 108. In addition, the core network 107 may provide the WTRUs 102a, 102b, and 102c with access to the networks 112, which may include other wired or wireless networks that are owned and/or operated by other service providers.
The RAN 105 may include gNode-Bs 180a and 180b. It will be appreciated that the RAN 105 may include any number of gNode-B s. The gNode-Bs 180a and 180b may each include one or more transceivers for communicating with the WTRUs 102a and 102b over the air interface 117. When integrated access and backhaul connection are used, the same air interface may be used between the WTRUs and gNode-Bs, which may be the core network 109 via one or multiple gNBs. The gNode-Bs 180a and 180b may implement MIMO, MU-MIMO, and/or digital beamforming technology. Thus, the gNode-B 180a, for example, may use multiple antennas to transmit wireless signals to, and receive wireless signals from, the WTRU 102a. It should be appreciated that the RAN 105 may employ of other types of base stations such as an eNode-B. It will also be appreciated the RAN 105 may employ more than one type of base station. For example, the RAN may employ eNode-Bs and gNode-Bs.
The N3IWF 199 may include a non-3GPP Access Point 180c. It will be appreciated that the N3IWF 199 may include any number of non-3GPP Access Points. The non-3GPP Access Point 180c may include one or more transceivers for communicating with the WTRUs 102c over the air interface 198. The non-3GPP Access Point 180c may use the 802.11 protocol to communicate with the WTRU 102c over the air interface 198.
Each of the gNode-Bs 180a and 180b may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the uplink and/or downlink, and the like. As shown in
The core network 109 shown in
In the example of
In the example of
The AMF 172 may be connected to the RAN 105 via an N2 interface and may serve as a control node. For example, the AMF 172 may be responsible for registration management, connection management, reachability management, access authentication, access authorization. The AMF may be responsible forwarding user plane tunnel configuration information to the RAN 105 via the N2 interface. The AMF 172 may receive the user plane tunnel configuration information from the SMF via an N11 interface. The AMF 172 may generally route and forward NAS packets to/from the WTRUs 102a, 102b, and 102c via an N1 interface. The N1 interface is not shown in
The SMF 174 may be connected to the AMF 172 via an N11 interface. Similarly the SMF may be connected to the PCF 184 via an N7 interface, and to the UPFs 176a and 176b via an N4 interface. The SMF 174 may serve as a control node. For example, the SMF 174 may be responsible for Session Management, IP address allocation for the WTRUs 102a, 102b, and 102c, management and configuration of traffic steering rules in the UPF 176a and UPF 176b, and generation of downlink data notifications to the AMF 172.
The UPF 176a and UPF 176b may provide the WTRUs 102a, 102b, and 102c with access to a Packet Data Network (PDN), such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, and 102c and other devices. The UPF 176a and UPF 176b may also provide the WTRUs 102a, 102b, and 102c with access to other types of packet data networks. For example, Other Networks 112 may be Ethernet Networks or any type of network that exchanges packets of data. The UPF 176a and UPF 176b may receive traffic steering rules from the SMF 174 via the N4 interface. The UPF 176a and UPF 176b may provide access to a packet data network by connecting a packet data network with an N6 interface or by connecting to each other and to other UPFs via an N9 interface. In addition to providing access to packet data networks, the UPF 176 may be responsible packet routing and forwarding, policy rule enforcement, quality of service handling for user plane traffic, downlink packet buffering.
The AMF 172 may also be connected to the N3IWF 199, for example, via an N2 interface. The N3IWF facilitates a connection between the WTRU 102c and the 5G core network 170, for example, via radio interface technologies that are not defined by 3GPP. The AMF may interact with the N3IWF 199 in the same, or similar, manner that it interacts with the RAN 105.
The PCF 184 may be connected to the SMF 174 via an N7 interface, connected to the AMF 172 via an N15 interface, and to an Application Function (AF) 188 via an N5 interface. The N15 and N5 interfaces are not shown in
The UDR 178 may act as a repository for authentication credentials and subscription information. The UDR may connect to network functions, so that network function can add to, read from, and modify the data that is in the repository. For example, the UDR 178 may connect to the PCF 184 via an N36 interface. Similarly, the UDR 178 may connect to the NEF 196 via an N37 interface, and the UDR 178 may connect to the UDM 197 via an N35 interface.
The UDM 197 may serve as an interface between the UDR 178 and other network functions. The UDM 197 may authorize network functions to access of the UDR 178. For example, the UDM 197 may connect to the AMF 172 via an N8 interface, the UDM 197 may connect to the SMF 174 via an N10 interface. Similarly, the UDM 197 may connect to the AUSF 190 via an N13 interface. The UDR 178 and UDM 197 may be tightly integrated.
The AUSF 190 performs authentication related operations and connects to the UDM 178 via an N13 interface and to the AMF 172 via an N12 interface.
The NEF 196 exposes capabilities and services in the 5G core network 109 to Application Functions (AF) 188. Exposure may occur on the N33 API interface. The NEF may connect to an AF 188 via an N33 interface and it may connect to other network functions in order to expose the capabilities and services of the 5G core network 109.
Application Functions 188 may interact with network functions in the 5G Core Network 109. Interaction between the Application Functions 188 and network functions may be via a direct interface or may occur via the NEF 196. The Application Functions 188 may be considered part of the 5G Core Network 109 or may be external to the 5G Core Network 109 and deployed by enterprises that have a business relationship with the mobile network operator.
Network Slicing is a mechanism that could be used by mobile network operators to support one or more ‘virtual’ core networks behind the operator's air interface. This involves ‘slicing’ the core network into one or more virtual networks to support different RANs or different service types running across a single RAN. Network slicing enables the operator to create networks customized to provide optimized solutions for different market scenarios which demands diverse requirements, e.g. in the areas of functionality, performance and isolation.
3GPP has designed the 5G core network to support Network Slicing. Network Slicing is a good tool that network operators can use to support the diverse set of 5G use cases (e.g., massive IoT, critical communications, V2X, and enhanced mobile broadband) which demand very diverse and sometimes extreme requirements. Without the use of network slicing techniques, it is likely that the network architecture would not be flexible and scalable enough to efficiently support a wider range of use cases need when each use case has its own specific set of performance, scalability, and availability requirements. Furthermore, introduction of new network services should be made more efficient.
Referring again to
The core network 109 may facilitate communications with other networks. For example, the core network 109 may include, or may communicate with, an IP gateway, such as an IP Multimedia Subsystem (IMS) server, that serves as an interface between the 5G core network 109 and a PSTN 108. For example, the core network 109 may include, or communicate with a short message service (SMS) service center that facilities communication via the short message service. For example, the 5G core network 109 may facilitate the exchange of non-IP data packets between the WTRUs 102a, 102b, and 102c and servers or applications functions 188. In addition, the core network 170 may provide the WTRUs 102a, 102b, and 102c with access to the networks 112, which may include other wired or wireless networks that are owned and/or operated by other service providers.
The core network entities described herein and illustrated in
WTRUs A, B, C, D, E, and F may communicate with each other over a Uu interface 129 via the gNB 121 if they are within the access network coverage 131. In the example of
WTRUs A, B, C, D, E, and F may communicate with RSU 123a or 123b via a Vehicle-to-Network (V2N) 133 or Sidelink interface 125b. WTRUs A, B, C, D, E, and F may communicate to a V2X Server 124 via a Vehicle-to-Infrastructure (V2I) interface 127. WTRUs A, B, C, D, E, and F may communicate to another UE via a Vehicle-to-Person (V2P) interface 128.
The processor 118 may be a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors in association with a DSP core, a controller, a microcontroller, Application Specific Integrated Circuits (ASICs), Field Programmable Gate Array (FPGAs) circuits, any other type of integrated circuit (IC), a state machine, and the like. The processor 118 may perform signal coding, data processing, power control, input/output processing, and/or any other functionality that enables the WTRU 102 to operate in a wireless environment. The processor 118 may be coupled to the transceiver 120, which may be coupled to the transmit/receive element 122. While
The transmit/receive element 122 of a UE may be configured to transmit signals to, or receive signals from, a base station (e.g., the base station 114a of
In addition, although the transmit/receive element 122 is depicted in
The transceiver 120 may be configured to modulate the signals that are to be transmitted by the transmit/receive element 122 and to demodulate the signals that are received by the transmit/receive element 122. As noted above, the WTRU 102 may have multi-mode capabilities. Thus, the transceiver 120 may include multiple transceivers for enabling the WTRU 102 to communicate via multiple RATs, for example NR and IEEE 802.11 or NR and E-UTRA, or to communicate with the same RAT via multiple beams to different RRHs, TRPs, RSUs, or nodes.
The processor 118 of the WTRU 102 may be coupled to, and may receive user input data from, the speaker/microphone 124, the keypad 126, and/or the display/touchpad/indicators 128 (e.g., a liquid crystal display (LCD) display unit or organic light-emitting diode (OLED) display unit. The processor 118 may also output user data to the speaker/microphone 124, the keypad 126, and/or the display/touchpad/indicators 128. In addition, the processor 118 may access information from, and store data in, any type of suitable memory, such as the non-removable memory 130 and/or the removable memory 132. The non-removable memory 130 may include random-access memory (RAM), read-only memory (ROM), a hard disk, or any other type of memory storage device. The removable memory 132 may include a subscriber identity module (SIM) card, a memory stick, a secure digital (SD) memory card, and the like. The processor 118 may access information from, and store data in, memory that is not physically located on the WTRU 102, such as on a server that is hosted in the cloud or in an edge computing platform or in a home computer (not shown).
The processor 118 may receive power from the power source 134, and may be configured to distribute and/or control the power to the other components in the WTRU 102. The power source 134 may be any suitable device for powering the WTRU 102. For example, the power source 134 may include one or more dry cell batteries, solar cells, fuel cells, and the like.
The processor 118 may also be coupled to the GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) regarding the current location of the WTRU 102. In addition to, or in lieu of, the information from the GPS chipset 136, the WTRU 102 may receive location information over the air interface 115/116/117 from a base station (e.g., base stations 114a, 114b) and/or determine its location based on the timing of the signals being received from two or more nearby base stations. It will be appreciated that the WTRU 102 may acquire location information by way of any suitable location-determination method.
The processor 118 may further be coupled to other peripherals 138, which may include one or more software and/or hardware modules that provide additional features, functionality, and/or wired or wireless connectivity. For example, the peripherals 138 may include various sensors such as an accelerometer, biometrics (e.g., finger print) sensors, an e-compass, a satellite transceiver, a digital camera (for photographs or video), a universal serial bus (USB) port or other interconnect interfaces, a vibration device, a television transceiver, a hands free headset, a Bluetooth® module, a frequency modulated (FM) radio unit, a digital music player, a media player, a video game player module, an Internet browser, and the like.
The WTRU 102 may be included in other apparatuses or devices, such as a sensor, consumer electronics, a wearable device such as a smart watch or smart clothing, a medical or eHealth device, a robot, industrial equipment, a drone, a vehicle such as a car, truck, train, or an airplane. The WTRU 102 may connect to other components, modules, or systems of such apparatuses or devices via one or more interconnect interfaces, such as an interconnect interface that may comprise one of the peripherals 138.
In operation, processor 91 fetches, decodes, and executes instructions, and transfers information to and from other resources via the computing system's main data-transfer path, system bus 80. Such a system bus connects the components in computing system 90 and defines the medium for data exchange. System bus 80 typically includes data lines for sending data, address lines for sending addresses, and control lines for sending interrupts and for operating the system bus. An example of such a system bus 80 is the PCI (Peripheral Component Interconnect) bus.
Memories coupled to system bus 80 include random access memory (RAM) 82 and read only memory (ROM) 93. Such memories include circuitry that allows information to be stored and retrieved. ROMs 93 generally contain stored data that cannot easily be modified. Data stored in RAM 82 may be read or changed by processor 91 or other hardware devices. Access to RAM 82 and/or ROM 93 may be controlled by memory controller 92. Memory controller 92 may provide an address translation function that translates virtual addresses into physical addresses as instructions are executed. Memory controller 92 may also provide a memory protection function that isolates processes within the system and isolates system processes from user processes. Thus, a program running in a first mode may access only memory mapped by its own process virtual address space; it cannot access memory within another process's virtual address space unless memory sharing between the processes has been set up.
In addition, computing system 90 may contain peripherals controller 83 responsible for communicating instructions from processor 91 to peripherals, such as printer 94, keyboard 84, mouse 95, and disk drive 85.
Display 86, which is controlled by display controller 96, is used to display visual output generated by computing system 90. Such visual output may include text, graphics, animated graphics, and video. The visual output may be provided in the form of a graphical user interface (GUI). Display 86 may be implemented with a CRT-based video display, an LCD-based flat-panel display, gas plasma-based flat-panel display, or a touch-panel. Display controller 96 includes electronic components required to generate a video signal that is sent to display 86.
Further, computing system 90 may contain communication circuitry, such as for example a wireless or wired network adapter 97, that may be used to connect computing system 90 to an external communications network or devices, such as the RAN 103/104/105, Core Network 106/107/109, PSTN 108, Internet 110, WTRUs 102, or Other Networks 112 of
It is understood that any or all of the apparatuses, systems, methods and processes described herein may be embodied in the form of computer executable instructions (e.g., program code) stored on a computer-readable storage medium which instructions, when executed by a processor, such as processors 118 or 91, cause the processor to perform and/or implement the systems, methods and processes described herein. Specifically, any of the steps, operations, or functions described herein may be implemented in the form of such computer executable instructions, executing on the processor of an apparatus or computing system configured for wireless and/or wired network communications. Computer readable storage media includes volatile and nonvolatile, removable and non-removable media implemented in any non-transitory (e.g., tangible or physical) method or technology for storage of information, but such computer readable storage media do not include signals. Computer readable storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other tangible or physical medium which may be used to store the desired information and which may be accessed by a computing system.
The following is a list of acronyms relating to service layer technologies that may appear in the description below. Unless otherwise specified, the acronyms used herein refer to the corresponding term listed below:
Up Link (UL) power control in a NR system is used mainly for limiting intracell and intercell interference, reducing UE power consumption with received power for proper decoding, and ensuring the overall system UL throughput performance.
Beam-based UL Transmit Power Control (TPC) in open-loop and closed-loop are specified in TS 38.213 for different UL channels as well as UL signals (see 3GPP TS 38.213 Physical layer procedures for control, Release 15, V15.3.0), which may be generalized with the following equation for the UL transmit power (in dBm) at transmission occasion i:
P(i,j,q,l)=min{Pc max(i),P0(j)+10×log10(2μ×MRB(i))+α(j)×PL(q)+ΔTF(i)+ƒ(i,l)}
For open-loop TPC, the beam-based transmit power may be set based on the maximum allowable transmission power (e.g., Pcmax(i)), normalized target power level at a gNB's receiver (e.g., P0(j) for a configuration with j<2 or beam pair association with j≥2), transmitted Resource Blocks (RBs), e.g., MRB(i)) scaled with the associated numerology (e.g., subcarrier spacing 2μ), UL Path Loss (PL) estimated with the scaled (e.g., α(j) for fractional scaled) Downlink (DL) path loss measurement (e.g., PL(q)) with a DL Reference Signal (RS) (e.g., reference signal resource index q) associated to the beam pair link, and the adjustment with the associated Modulation Coding Scheme (MCS) (e.g., ΔTF(i)).
For closed-loop TPC, the beam-based transmit power may be adjusted based on Transmit Power Control command from the gNB, for example ƒ(i,l) as power control adjustment state of loop l for increasing or decreasing the power at transmission occasion i.
Sidelink transmit power control is specified in LTE, where only open-loop power control is conducted for sidelink V2X communications (see 3GPP TS 36.213 Physical layer procedures, Release 15, V15.3.0). The open-loop power control is based on either path loss estimated on downlink from an eNB or based on the maximum allowable transmit power for emergency service when under the eNB coverage; or is based on a fixed preconfigured transmit power level when out of an eNB's coverage.
As illustrated in
As depicted in
Also, as illustrated in
Also shown in
In LTE V2X, the transmit power control (TPC) is conducted as open-loop power control with the path loss estimated from the DownLink (DL) measurements which is mainly for inband interference management, e.g., the closer a vehicle UE gets to eNB, the lower the transmit power level on its sidelink. For emergency scenario, the network switches a vehicle UE to operate at a maximum power level. For out of network coverage, a vehicle UE's maximum transmit power may be set at three different levels for discovery by the higher layer. Overall, the sidelink transmit power is not optimized for sidelink radio link quality, or in another words, not optimized in proximity for sidelink communications.
To support the advanced V2X use cases, proximity based sidelink optimization is becoming important to ensure the radio link quality and therefore to meet much more stringent latency and reliability requirement. Specifically, the following problems for transmit power control may need to be addressed:
When a vehicle UE is operating in NR Mode 1 or Mode 2 under the network coverage, how does the UE balance the proximity based sidelink transmit power control with the cell based inband interference control?
When a vehicle UE is operating in NR Mode 2 out of the network coverage, how does the UE optimize the proximity based sidelink transmit power control, as well as managing the interference in the proximity?
Different sidelink Transmit Power Control (TPC) schemes are disclosed herein. Note that the terms UE and vehicle UE are used interchangeably, terms groupcast and multicast are used interchangeably, and terms beam and panel are used interchangeably herein.
Methods and systems for Sidelink Transmit Power Control are disclosed. Example methods and systems may include but are not limited to path loss estimation for sidelink including Reference Signals (RS) for path loss measurement and path loss estimation for proximity based transmit power control, open-loop transmit power control on sidelink including synchronization, discovery, broadcast, groupcast or multicast, and unicast, as well as closed-loop transmit power control on sidelink including two-way transmit power control on sidelink for unicast and two-way transmit power control on sidelink for groupcast or multicast.
Methods and systems for transmit power sharing are disclosed. Example methods and systems may include but are not limited to transmit power sharing between uplink and sidelink and transmit power sharing between sidelinks.
An example method may comprise receiving one or more of a sidelink quality of service configuration, a sidelink transmit power control configuration, or an interference control configuration; determining one or more of a first path loss measurement from a first device or a second path loss measurement from a second device on sidelink; estimating a sidelink transmit power based on one or more of the sidelink quality of service configuration, the sidelink transmit power control configuration, the interference control configuration, the first path loss measurement from the first device, or the second path loss measurement from the second device on sidelink; and sending a transmission to the second device on sidelink based on the estimated sidelink transmit power.
The sidelink quality of service configuration may comprise one or more of a minimum sidelink communication range, a priority, or a latency. The sidelink transmit power control configuration per sidelink bandwidth part and/or per sidelink beam or antenna may comprise one or more of: a sidelink target power, a sidelink path loss scaling factor, a sidelink maximum transmit power, an initial sidelink transmit power, a sidelink transmit power adjustment, or a sidelink reference signal configuration for path loss measurement. The interference control configuration per sidelink bandwidth part and/or per sidelink beam or antenna may comprise one or more of a path loss scaling factor, a reference signal configuration for path loss measurement, or a transmit power of a reference signal for the path loss measurement.
Determining the first path loss measurement from the first device may comprises one or more of: measuring a path loss on downlink from a gNB using a synchronization signal block (SSB) or a channel state information reference signal (CSI-RS); or measuring a path loss on sidelink from the first device using a sidelink synchronization signal block (S-SSB), a sidelink channel state information reference signal (S-CSI-RS), or a sidelink demodulation reference signal (S-DMRS). Determining the second path loss measurement from the second device on sidelink may comprise one or more of: measuring a path loss on sidelink using a sidelink synchronization signal block (S-SSB), a sidelink channel state information reference signal (S-CSI-RS), or a sidelink demodulation reference signal (S-DMRS) from the second device; or receiving a measurement of sidelink reference signal received power (S-RSRP) from the second device for a second path loss or receiving a measured second path loss from the second device, wherein the measurement comprises one or more of a sidelink synchronization signal block (S-SSB), a sidelink channel state information reference signal (S-CSI-RS), or a sidelink demodulation reference signal (S-DMRS).
Estimating the sidelink transmit power may comprise one or more of: determining a sidelink transmit power based on a configured sidelink transmit power associated with a quality of service; and determining a sidelink transmit power using interference control based on one or more of the first path loss with the first device and/or using the sidelink path loss compensation based on the second path loss with the second device on sidelink. Sending a transmission may comprise one or more of broadcasting a sidelink synchronization signal block, broadcasting a sidelink discovery message, sending a data packet and/or sidelink channel state information reference signal via a sidelink unicast, a sidelink groupcast or multicast, or a sidelink broadcast, and sending a feedback for a sidelink unicast or a sidelink groupcast or multicast.
Sidelink path loss estimation is based on a radio link path loss measurement, which may be measured within the network coverage or without the network coverage.
If a UE is under a network coverage, e.g., under a gNB as shown in
If the measured DL path loss is used for Sidelink (SL) power control, it is mainly for the cell based inband interference management and not for the sidelink radio link quality. As shown in
For proper transmit power setting to ensure certain performance requirement on a sidelink in proximity, sidelink path loss measurement is proposed for sidelink open-loop transmit power control to compensate for the radio channel attenuation or fading to a signal on a sidelink. As illustrated in
Due to radio channel's reciprocal property of a Time Division Duplex (TDD) system on a sidelink, the path loss based on the measuring signal on sidelink may be applied to either direction of a paired sidelinks, therefore only one UE of a paired sidelinks needs to send a reference signal or to measure the path loss from a reference signal. For example, if UE A on sidelink pair SLA and SLB, as shown in
When a UE is out of the network coverage, the sidelink path loss measurement may be conducted in the examples depicted in
As shown in
A full sidelink path loss measurement for each sidelink radio quality is exemplified in
The path loss measurement on the downlink or sidelink may be for example Reference Signal Received Power (RSRP), which may be based on periodic measuring signals (e.g., DL SS and/or DMRS of SSB or periodic CSI-RS; sidelink S-SS and/or S-DMRS of S-SSB, or periodic S-CSI-RS) and/or aperiodic measuring signals (e.g., DL DMRS of PDCCH or PDSCH, or aperiodic CSI-RS; sidelink S-DMRS of PSDCH, PSCCH or PSSCH, or aperiodic S-CSI-RS) sent on a downlink or sidelink respectively.
The downlink path loss may be estimated with the following equation as an example,
DL Path Loss=transmit power of SS/DMRS/CSI-RS−RSRP of SS/DMRS/CSI-RS, where RSRP may be measured at the physical layer, e.g. L1 measurement at each transmission or monitoring occasion or measuring window, and/or filtered by the higher layer for large scale channel fading, e.g., L2 or L3 filtering with a L2 or L3 filtering window or time interval.
The sidelink path loss may be estimated with the following equation as an example,
SL Path Loss=transmit power of S-SS/S-DMRS/S-CSI-RS−RSRP of S-SS/S-DMRS/S-CSI-RS, where RSRP may be measured at the physical layer, e.g. L1 measurement at each transmission or monitoring occasion or measuring window, and/or filtered by the higher layer for large scale channel fading, e.g., L2 or L3 filtering with a L2 or L3 filtering window or time interval.
A V2X communication topology structure may be very dynamic due to different speeds and moving directions among UEs in a proximity, e.g., at the intersection of an urban area. A V2X communication topology structure may be very static due to the same speeds and moving directions among UEs in a proximity, e.g., a car platoon. Therefore, a reference signal for path loss measurement, e.g., S-SSB, S-CSI-RS or S-DMRS, may be dynamic (e.g., aperiodic) or static (e.g., periodic or semi-persistent) for a V2X service in a proximity.
Periodic transmission occasions of a sidelink measuring signal and the related transmit power should be known to UEs in a proximity for sidelink path loss measurements. A periodic sidelink measuring signal may be S-SS and/or S-DMRS of PSBCH of an S-SSB, periodic S-CSI-RS, S-DMRS of PSCCH or PSSCH for periodic message.
The transmission occasions of a periodic sidelink measuring signal may include, for example, an allocation in time within a slot or subframe or a frame, e.g., Timesymbol, and period, e.g., Timeperiod in symbols, slots, subframes or frames; an allocation in frequency, e.g., FrequencyPRB_num as Physical Resource Block (PRB) number or index, or Frequencysubch_num as subchannel number or index, or FrequencyRE_num as Resource Element (RE) number or index, or Frequencypattern as frequency pattern within a sidelink bandwidth part (SL-BWP); and an allocation in space, SSBindex for S-SSB or SCSIRSID or SCSIRSRSindex for S-CSI-RS, or Quasi-co-location (QCL) relationship with S-SSB or S-CSI-RS or Transmission Configuration Indicator (TCI) state associated with the S-SSB or S-CSI-RS for S-DMRS port of PSSCH.
The transmission occasion may also be indicated by the configuration ID or index, e.g., S-SSB_ConfID or S-SSB_Configindex for S-SSB, S-CSIRS_ConfigID or S-CSIRS_Configindex for S-CSI-RS, S-DMRS_PSSCH_ConfigID or S-DMRS_PSSCH_Configindex for S-DMRS of a PSSCH, wherein the configuration may include the allocation in time, frequency, and space respectively.
The transmit power may be, for example, S-SSBpower as the transmit power level and/or SDMRS_SSSBpoweroffset as the power offset from the S-SS for S-DMRS of an S-SSB; S-CSIRSpower for transmit power level and/or S-CSIRSpoweroffset for transmit power level offset from S-SSB of a periodic CSI-RS; PSSCHpower as the transmit power level for S-DMRS of PSSCH if same power level as the associated PSSCH and/or SDMRSPSSCHpoweroffset as the power offset for S-DMRS of PSSCH from the associated PSSCH power level.
For example, the periodic transmission occasions and related transmit power of a sidelink measuring signal, e.g., S-SS and/or S-DMRS of PSBCH, periodic S-CSI-RS, S-DMRS of PSSCH carrying periodic message with fixed transmit power level (e.g., maximum transmit power for broadcast), etc., may be pre-configured by the access network or V2X server or by the service provider or device manufacture, or statically configured via Radio Resource Control (RRC) or V2X Non-Access Stratum (NAS) from the access network or V2X server if within the network coverage; or by a Road Side Unit (RSU), a proximity lead, a scheduling UE, or a group lead while joining a group or by a peer UE while pairing with the UE via Sidelink Radio Resource Control (SL-RRC) at PC5 interface, e.g. PC5-RRC, or the broadcasting message carried on PSBCH of a selected S-SSB on sidelink as sidelink system information. For another example, the periodic transmission occasions and related transmit power of a sidelink measuring signal, e.g., periodic S-CSI-RS, S-DMRS of PSSCH carrying periodic message with semi-static transmit power level, etc., may also be semi-statically indicated by MAC CE from the access network if within the network coverage, or a Road Side Unit (RSU), a proximity lead, a scheduling UE, a group lead or a paired UE via sidelink MAC (SL-MAC) CE via SL-RRC or the broadcasting message carried on PSSCH on sidelink. If power control is applied to the periodic sidelink measuring signal, the corresponding transmit power, S_CSIRS_TxPower for periodic S-CSI-RS, or SL_PSSCH_TxPower for S-DMRS of PSSCH, may also be dynamically signaled by gNB on downlink with the Downlink Control Information (DCI) carried on PDCCH from the access network if within the network coverage, or dynamically signaled on sidelink with the Sidelink Control Information (SCI) carried on PSCCH from an RSU, a proximity lead, a scheduling UE, a group lead or a transmitting UE.
Similar to the periodic measuring signals, aperiodic transmission occasions of a sidelink measuring signal and the related transmit power should be known to UEs in a proximity for sidelink path loss measurements. An aperiodic sidelink measuring signal may be aperiodic S-CSI-RS, S-DMRS of PSDCH for discovery, S-DMRS of PSCCH for scheduling and decoding, or S-DMRS of PSSCH for aperiodic messaging.
Similar to the periodic measuring signals, the transmission occasions of an aperiodic sidelink measuring signal may include, for example, an allocation in time within a slot or subframe or a frame, e.g., Timesymbol, length in time, e.g., Timelenth in symbols, slots, subframes or frames, or pattern in time, e.g., Timepattern such as a bitmap in symbol with a slot, a subframe or a frame; an allocation in frequency, e.g., FrequencyPRB_num as Physical Resource Block (PRB) number or index, or Frequencysubch_num as subchannel number or index, or FrequencyRE_num as Resource Element (RE) number or index Frequencypattern as frequency pattern within a sidelink bandwidth part (SL-BWP); and an allocation in space, ASCSIRSID or ASCSIRSRSindex for aperiodic S-CSI-RS, or QCL relationship with S-SSB or S-CSI-RS or Transmission Configuration Indicator (TCI) state associated with the S-SSB or S-CSI-RS for S-DMRS port of PSDCH, S-DMRS port of PSCCH, or S-DMRS port of PSSCH.
Similar to the periodic measuring signals, the transmission occasion may also be indicated by the configuration ID or index, e.g., AS-CSIRS_ConfigID or AS-CSIRS_Configindex for aperiodic S-CSI-RS, S-DMRS_PSDCH_ConfigID or S-DMRS_PSDCH_Configindex for S-DMRS of a PSDCH, S-DMRS_PSCCH_ConfigID or S-DMRS_PSCCH_Configindex for S-DMRS of a PSCCH, S-DMRS_PSSCH_ConfigID, or S-DMRS_PSSCH_Configindex for S-DMRS of a PSSCH with aperiodic messaging, wherein the configuration may include the allocation in time, frequency, and space respectively.
Similar to the periodic measuring signals, the transmit power may be, for example, AS-CS/RSpower for transmit power level and/or AS-CS/RSpoweroffset for transmit power level offset from S-SSB of an aperiodic S-CSI-RS; PSDCHpower as the transmit power level for S-DMRS of PSDCH if same power level as the associated PSDCH and/or SDMRSPSDCHpoweroffset as the power offset for S-DMRS from the associated PSDCH power level; PSCCHpower as the transmit power level for S-DMRS of PSCCH if same power level as the associated PSCCH and/or SDMRSPSCCHpoweroffset as the power offset for S-DMRS from the associated PSCCH power level; PSSCHpower as the transmit power level for S-DMRS of PSSCH if same power level as the associated PSSCH and/or SDMRSPSSCHpoweroffset as the power offset for S-DMRS from the associated PSSCH power level.
Similar to the periodic measuring signals, the transmission occasions and related transmit power of an aperiodic sidelink measuring signal may be pre-configured or configured via RRC on Uu interface or SL-RRC on PC5 interface, semi-statically via MAC CE on Uu interface or SL-MAC CE on PC5 interface or dynamically indicated via DCI on Uu interface by a gNB or a V2X server via Uu if under the network coverage or via SCI on PC5 interface by an RSU, a proximity lead, a scheduling UE, a group lead or a paired UE or the transmitting UE if out of the network coverage. The transmission may be activated and/or deactivated by DCI on downlink sent from a gNB or V2X server if within the network coverage, or by SCI on sidelink sent from an RSU, a proximity lead, a scheduling UE, a group lead if under locally centralized control, or self-announced or self-managed by a paired UE or the transmitting UE for a fully distributive V2X network in proximity. If S-DMRS of PSCCH or PSSCH or S-CSI-RS transmitted with PSSCH, the transmit power may be adjusted via transmit power control. But the power level is not expected to change during each path loss measurement period or interval. The transmit power may also be indicated in the SCI associated to the PSSCH, e.g., indicated in the SCI for decoding the associated PSSCH. For example, a transmitting UE may send S-DMRS associated to a PSSCH or insert S-CSI-RS with a PSSCH, a receiving UE or receiving UEs may measure the sidelink RSRP and may report to the transmitting UE. The reporting occasion or time interval may be configured via RRC or SL-RRC, or MAC CE or SL MAC CE, and the triggering of reporting may be implicitly from receiving a S-DMRS or S-CSI-RS with a PSSCH or may be explicitly from an indication carried in SCI or from SL-MAC CE.
For static synchronization sources, e.g., S-SSB, periodic transmissions may be more efficient. For dynamic synchronization sources, e.g., S-SSB, or S-CSI-RS or S-DMRS as a sidelink reference signal for synchronization (SL-RS-Sync), aperiodic transmissions may be a better choice for the tradeoff between needed synchronization sources in a proximity and interferences among the synchronization sources in a proximity, as well as the efficient usage of sidelink resources for transmitting S-SSBs in a proximity.
The S-SS and/or S-DMRS of PSBCH within an S-SSB may be transmitted periodically on a sidelink from an RSU, a proximity lead, a group lead or a synchronization source UE, with the transmit power as part of S-SSB configuration for configuration based transmit power control for S-SSB or with the transmit power indicated in S-SSB transmission for open-loop transmit power control for S-SSB.
Aperiodic S-SSB(s) may be activated or deactivated on a sidelink based on the synchronization source situation in the proximity, and the transmit power may be as part of the S-SSB configuration activated or deactivated by an RSU, proximity lead, group lead or a synchronization source UE, the transmit power may be indicated in S-SSB transmission for open-loop transmit power control for S-SSB.
Similarly, the S-CSI-RS may be transmitted periodically on a sidelink from an RSU, a proximity lead, a scheduling UE, a group lead or a synchronization source UE or a paired UE with the transmit power as part of the S-CSI-RS configuration or with the transmit power based on the S-SSB transmit power setting (e.g., with an offset from S-SSB transmit power) or with the transmit power indicated for S-CSI-RS transmission for open-loop transmit power control for S-CSI-RS.
Aperiodic S-CSI-RS(s) may be activated or deactivated for a time interval, or scheduled or inserted with a PSSCH transmission on a sidelink, based on the S-CSI-RS allocation and request in the proximity, and the transmit power may be as part of the aperiodic S-CSI-RS configuration activated or deactivated, or the transmit power may be indicated by S1-MAC CE or SCI for aperiodic S-CSI-RS transmission for open-loop transmit power control for aperiodic S-CSI-RS, or the transmit power may be based on the S-SSB transmit power with an offset for aperiodic S-CSI-RS transmit power level for a V2X service.
The S-DMRS of periodic PSDCH may be transmitted periodically from an RSU, a proximity lead, a scheduling UE, a group lead or a synchronization source UE or a UE wanting to be discovered with the transmit power as part of the PSDCH configuration, or based on the S-SSB transmit power with an offset for discovery transmit power level for a V2X service, or dynamically indicated for a PSDCH transmission per the transmit power control for a PSDCH.
The S-DMRS with an aperiodic PSDCH may also be transmitted if a UE wants to be discovered with the transmit power as part of the PSDCH configuration, or based on the S-SSB transmit power with an offset for discovery transmit power level for a V2X service, or dynamically indicated by SCI for a PSDCH transmission per the transmit power control for a PSDCH.
The S-DMRS of PSCCH and/or PSSCH may be transmitted periodically from an RSU, a proximity lead, a scheduling UE, a group lead or a synchronization source UE for periodic broadcasting messages as an example with the transmit power as part of the PSCCH and/or PSSCH configuration or dynamically indicated for a PSCCH and/or PSSCH transmission per the transmit power control for the PSCCH and/or PSSCH.
The S-DMRS with an aperiodic PSCCH and/or PSSCH may also be transmitted for dynamic signal and/or data transmissions with the transmit power indicated implicitly or explicitly with SCI as part of open-loop and/or closed-loop transmit power control for the PSCCH and/or PSSCH.
For NR sidelink, open-loop transmit power control may be conducted per a selected power value for a V2X service based on its QoS requirements, such as priority, latency, reliability, minimum service range, interference, congestion control, etc., from a set of transmit power values configured for a set of V2X services, e.g. configuration based open-loop power control; and/or may be conducted per the path loss estimation based on DL path loss measurements for interference control and/or SL path loss measurements for sidelink path loss compensation as discussed previously, e.g., path loss based open-loop power control with interference control and/or sidelink path loss compensation. A high-level overview of the proposed open-loop transmit power control procedure is depicted in
At step 1, configure UE QoS parameters, interference control parameters, transmit power control parameters: The UE's transmit power control may contain the following configurable parameters as an example:
Cell or proximity based: max power in cell and/or in proximity, max. coverage range in proximity, max. allowable interference level in proximity, etc.;
QoS requirements of a V2X service: priority, latency, reliability, minimum communication range, etc.;
Measuring signal configurations: resource configurations, beam association or correspondence, antenna or antenna port configuration, period or time duration for measuring, transmit power level, etc.;
Path loss measurement configurations: measuring occasions and time window, max. and min. RSRP thresholds, filtering parameters, etc.;
Path loss estimation parameters: max. and min. path loss estimation thresholds, scaling factor, numerology scaling, target power level, etc.;
Interference parameters: interference level thresholds, interference reference points (e.g., gNB of access network, RSU, proximity lead, group lead, or a synchronization source UE, etc. in a proximity of a UE), interference measurement configurations and filtering parameters, interference scaling factors, target interference power level, etc.; and
Transmit power control configurations: transmit power control (TPC) for difference signal or message transmissions of a V2X service, TPC for different communication types (e.g., unicast, groupcast, or broadcast), TPC for different transmission modes (e.g. NR Mode 1 or Mode 2), etc.
These parameters may be pre-configured and/or configured or reconfigured via RRC or SL-RRC or V2X NAS configuration if within a network coverage. They may also be pre-configured by manufacture or service provider via V2X server, configured during group discovery and joining a group or peer discovery and pairing with a peer UE, or broadcasted via sidelink broadcast messages (e.g., sidelink system information) from an RSU, proximity lead, a group lead or a synchronization source UE.
At step 2, perform L1 RSRP measurements in proximity: The physical layer or Layer 1 (L1) RSRP measurements, which may be filtered with layer 2 or layer 3 filters for higher layer RSRP, in the proximity may be measured from the following measuring signals as an example:
Downlink: SS and/or DMRS of PBCH of SSBs, or CSI-RS on Uu interface from gNB if within network coverage; and/or
Sidelinks: S-SS and/or S-DMRS of PSBCH of S-SSBs, S-CSI-RS, or S-DMRS of PSDCH, PSCCH and/or PSSCH, or a combination of them from RSUs, proximity leads, group leads, synchronization source UEs; or S-CSI-RS, or S-DMRS of PSDCH, PSCCH and/or PSSCH, or a combination of them from UEs in a proximity, e.g., from a transmitting UE or a receiving UE.
At step 3, transmission(s) for V2X service(s): any transmission for a V2X service or transmissions for V2X services in proximity configured or pre-scheduled? If no transmission for a V2X service is configured or pre-scheduled, go to step 4B; otherwise, go to Step 4A.
At step 4A, determine maximum transmit power for V2X services in a proximity: decide the maximum transmit power for V2X services in proximity per the QoS requirements of V2X services, such as priority, priority, latency, reliability, minimum communication range, etc., and interference level in proximity measured at step 2, as well as the maximum transmit power for a V2X service, e.g., Pmax, b, f, c per BWP b per carrier f per cell c.
At step 4B, determine maximum transmit power in a proximity: decide the maximum transmit power in a proximity per max. proximity range and interference level in proximity measured at step 2, as well as the maximum transmit power, e.g., Pcmax, f, c or Pprox, f, c per carrier f per cell c.
At step 5, a transmission ready on sidelink? Check if any signal or message is ready for a configured or scheduled transmission. If no, return to step 2; otherwise, move to step 6.
At step 6, path loss based? Check if the transmit power control is based on path loss. If yes, go to 7A1 and then 7A2; otherwise, go to 7B.
At step 7A1, measure path loss: Measure the sidelink path loss to the target UE(s) or receiving path loss measurement from the target UE(s) for a V2X service in proximity.
At step 7A2, determine transmit power: Decide the transmit power for the configured or scheduled transmission of a V2X service based on the following parameters.
Target power: on sidelink associated with the V2X service's QoS, such as priority, latency, reliability, minimum communication range, etc. target interference power level for interference control;
Path loss for sidelink radio link quality, measured at step 7A1;
Path loss for interference management, measured at step 2;
Max power in cell or proximity, etc.
At step 7B, determine transmit power: Decide the transmit power for the configured or scheduled transmission of a V2X service based on transmit power control parameters configured if there is no path loss measured or reported, e.g., power settings associated with the V2X service's QoS, max. power setting in cell or proximity, etc. Set transmit power based on configuration may be applicable when there is no sidelink path loss measurement for the initial transmissions such as S-SSB, or discovery channels. This is also applicable for the initial transmission or for a very low latency V2X services which may need to be transmitted immediately when the signal or data is ready for transmitting, e.g., no time for measuring the path loss as shown at step 7A1. Another example is using the path loss for interference management if no sidelink path loss is measured or received.
At step 8, transmit on sidelink: Transmit the signal or message on the sidelink at the determined transmit power level.
A synchronization source may be static or dynamic to the UE(s) in the proximity of the synchronization source. Some of the synchronization sources are at fixed absolution location without any mobility such as a gNB and an RSU, some of the synchronization sources are at fixed relative location with very low relative mobility to the UEs in its proximity such as a proximity lead and a group lead, and some of the synchronization sources are at changing relative locations with high relative mobility to some of the UEs in its proximity due to different speed and/or moving directions such as a synchronization source UE in a fully distributed V2X network in a proximity.
A V2X network may be formed in the proximity of a synchronization source such as a gNB, an RSU, a proximity lead, a group lead, or a synchronization source UE. Due to different speeds and moving directions, V2X networks may be merged or split according to the available synchronization sources.
For a fixed location or very low relative mobility synchronization source, the transmit power may be set per configuration, e.g. statically or fixed at a selected power level for a required V2X service range in a proximity.
For NR sidelink, the transmit power of Sidelink Primary Synchronization Signal (S-PSS) PSPSS, the transmit power of Sidelink Secondary Synchronization Signal (S-SSS) PSSSS, the transmit power of Physical Sidelink Broadcast Channel (PSBCH) PPSBCH may be configured by the higher layer with different QoS requirements, e.g., high power level may be configured for a V2X service which requires for high priority, low latency, high reliability, and/or large minimum communication range. For example, a set of {{circumflex over (P)}SPSS(i), {circumflex over (P)}SSSS(i), {circumflex over (P)}PSBCH(i)} may be configured corresponding to a V2X service proximity range {circumflex over (R)}prox(i), defined or mapped with the QoS requirements such as priority, latency, reliability, minimum communication range, interference, congestion control, etc., and with transmission beam or panel configuration j, where j is one of B beams or panel for simultaneous multi-beam or multi-panel or antenna transmission, as in the following:
where b is for an active sidelink BWP, f is for a carrier, c is for a serving cell, i is an index or ID for a V2X service mapped with the QoS requirements, and j is for a beam for multi-beam or for the panel for multi-panel transmissions.
In another way, the transmit power of Sidelink Synchronization Signal (S-SS) PS-SS or transmit power of Sidelink Synchronization Signal Block (S-SSB) PS-SSB may be configured for S-SSB containing S-PSS, S-SSS and PSBCH by the higher layer with different QoS requirements. For example, a set of {{circumflex over (P)}S-SS(i)} or a set of {{circumflex over (P)}S-SB(i)} may be configured corresponding to a V2X service proximity range {circumflex over (R)}prox(i) defined or mapped with the QoS requirements such as priority, latency, reliability, minimum communication range, interference, congestion control, etc., with transmit beam or panel or antenna j (where j is one of B beams or panels for simultaneous multi-beam or multi-panel or multi-antenna transmission), as follows:
There may be power offset between S-PSS and S-SSS, e.g., 0 dB, 3 dB. The power of S-SSS may be adjusted accordingly based on this offset. The power offset, e.g., PSSSSoffset, may be configured by the higher layer as part of the S-SS or S-SSB configuration.
If the S-DMRS of the PSBCH within a S-SSB is boosted with transmit power, the power offset PPSBCHoffset may be configured by the higher layer as part of the S-SSB configuration, where the power offset may be a constant or a set of {{circumflex over (P)}PBSCHoffset(i)} corresponding to proximity range {circumflex over (R)}prox(i) requirement for different V2X services. With the power offset, the transmit power of PSBCH within a S-SSB for a proximity range {circumflex over (R)}prox(i) of a V2X service on beam or panel j, where j is one of B beams or panels or antenna for simultaneous multi-beam or multi-panel or multi-antenna transmission, may be adjusted as follows.
The PCMAX,f,c is the configured maximum UE transmit power for carrier f of cell c, where cell c may be a serving cell if under the network coverage or a virtual “cell” in proximity if out of network coverage. A virtual cell may be one or multiple proximities formed with one or multiple V2X services respectively in a local area with one or multiple synchronization sources, where a virtual lead such as RSU or proximity lead may assist and manage the V2X configurations, interference level in the proximity, channel accessing, resource allocation and reservation, etc. among the V2X services in this local area.
TPC with Interference Management for Synchronization
For a moving synchronization source, its transmit power may be adjusted for inference management in a proximity. For example, the transmit power may be reduced if it is approaching a gNB or an RSU and the transmit power may be increased if it is departing from a gNB or an RSU, for reducing interference to the gNB or the RSU.
If inband interference management is included in the open-loop transmit power control for S-SSB, path losses may be measured from N interference reference points, such as gNB if under the network coverage as shown in
With a targeted power P0(i) on the sidelink adjusted with path loss PLb,f,cint(s, n) measured from all interference reference points (i.e. n=0, . . . N−1):
With a targeted power P0 (i, n) for interference reference point n (n=0, . . . N−1):
The PCMAX, f, c is the configured maximum UE transmit power for carrier f of cell c, where cell c may be a virtual “cell” in proximity if out of network coverage or a serving cell if under the network coverage.
The MRBSPSS, MRBSSSS, and MRBPSBCH are S-PSS, SSS and PSBCH frequency resource assignments in resource blocks respectively, which are scaled with 211 where pt. corresponds to a subcarrier spacing of a numerology.
The PO_SPSS,b,f,c(i), PO_SSSS,b,f,c(i), and PO_PSBCH,b,f,c(i) are S-PSS, S-SSS and PSBCH target powers respectively at the sidelink receiver or PO_SPSS,b,f,c(i, n), PO_SSSS,b,f,c(i, n), and PO
The αSPSS,b,f,cint(i, n), αSSSS,b,f,cint(i, n), and αPSBCH,b,f,cint(i, n) are S-PSS, S-SSS and PSBCH interference reference point path loss scaling factors, e.g., the weighting of the path loss measured from an interference reference point, respectively for a proximity range {circumflex over (R)}prox(i) of a V2X service from an interference reference point n on BWP b of carrier f of cell c, where cell c may be a virtual “cell” in proximity if out of network coverage or a serving cell if under the network coverage.
The PLb,f,cint(s,n) is the nth interference reference point path loss measured from an interference reference point n with measuring signal configuration s on BWP b of carrier f of cell c, where cell c may be a virtual “cell” in proximity if out of network coverage or a serving cell if under the network coverage. The reference points may be a gNB as illustrated in
For a proximity range {circumflex over (R)}prox(i) of a V2X service, the inband interference based path loss PLb,f,cint(s, n) may be weighted or scaled with αSPSS,b,f,cint(i, n), αSSSS,b,f,cint(i, n), and αPSBCH,b,f,cint(i, n) for S-PSS, SSS and PSBCH respectively. For example, a value of 0.5 for αPSSS,b,f,cint(i, n) may set the transmit power adjustment for S-PSS based on PLb,f,cint(s, n) measurement in half scale, e.g., less considering the inband interference; or a value of 1.0 for αPSSS,b,f,cint(i, n) may set the transmit power adjustment for S-PSS based on PLb,f,cint(s, n) measurement in full scale, e.g., fully considering the inband interference.
The f of ƒ(αSPSS,b,f,cint(i, n)·PLb,f,cint(s, n))|n=0N-1 or ƒ(PO
for most interference control, or a maximum function
for least interference control, or a scaled averaging function ηSPSS,b,f,cint(i)Σn=0n=N-1αSPSS,b,f,cint(i, n)·PLb,f,cint(s, n) or ηSPSS,b,f,cint(i)Σn=0n=N-1PO
For f as a minimum function, e.g.,
for example, if the PL measured on downlink from a gNB is smaller than the PL measured from an RSU, the PL of gNB is taken as the limit for more interference control, and thus a lower transmit power is set according to a closer distance to an interference reference point gNB (e.g. based on smaller PL which is resulting from closer distance with gNB). In this more interference control case, RSU will get less than required interference level.
For f as a maximum function,
for example, if the PL measured on downlink from a gNB is smaller than the PL measured from an RSU, the PL of RSU is taken as the limit for less interference control, and thus a higher transmit power is set according to a further distance to an interference reference point RSU (e.g. based on larger PL which is resulting from further distance with RSU). In this less interference control case, gNB will suffer more interference.
For f as a weighted average function, ƒ(αSPSS,b,f,cint(i, n)·PLb,f,cint(s, n))|n=0N-1 as ηSPSS,b,f,cint(i)Σn=0n=N-1αSPSS,b,f,cint(i, n)·PLb,f,cint(s, n), for example, if the PL measured on downlink from a gNB is smaller than the PL measured from an RSU, a scaled averaged value of gNB's PL and RSU's PL is taken as the limit for average interference control, and thus a transmit power is set higher for gNB's interference control and lower for RSU's interference control (e.g. based on an average PL between gNB and RSU). In this scaled average interference control, gNB will suffer a little more interference and RSU will get a little less than required interference, e.g. balanced interference control among the interference reference points.
The ηSPSS,b,f,cint(i), ηSSSS,b,f,cint(i), and ηPSBCH,b,f,cint(i) are S-PSS, S-SSS and PSBCH total interference reference point path loss scaling factors respectively for a proximity range {circumflex over (R)}prox(i) of a V2X service from N interference reference points on sidelink BWP b of carrier ƒ of cell c, where cell c may be a virtual “cell” in proximity if out of network coverage or a serving cell if under the network coverage. For example, ηSPSS,b,f,cint(i)=1/N is for the total path loss averaged with the weighted or scaled path losses measured from N interference reference points.
For NR sidelink, the transmit power for discovery message carried on dedicated Physical Sidelink Discovery Channel (PSDCH), e.g., PPSDCH, or on shared Physical Sidelink Control Channel (PSCCH), e.g., PPSCCHdisc, and Physical Sidelink Shared Channel (PSSCH), e.g., PPSSCHdisc, may be configured by the higher layer with different QoS requirements. For illustration purpose, PSDCH is used for discovery channel in the following examples. For example, a set of {{circumflex over (P)}PSDCH(i)} or {{circumflex over (P)}PSCCHdisc(i), {circumflex over (P)}PSSCHdisc(i)} may be configured corresponding to a proximity range {circumflex over (R)}prox(i) of a V2X service on beam j, where j is one of B beams for simultaneous multi-beam transmission, as follows:
If the transmit power for discovery is set based on the transmit power of S-SS or S-SSB, e.g., with a power offset configured or indicated by higher layer, the transmit power for discovery channels may be set as the follows using S-SSB as an example.
TPC with Interference Management for Discovery
If inband interference management is included in the open-loop transmit power control for discovery channel(s), the path loss measured from N interference reference points, such as gNB if under the network coverage as shown in
Similar to the synchronization power control, the transmit power control with interference management may also be generally described as the follows.
With a targeted power P0_PSDCH, b,f,c (i) on the sidelink receiver based on QoS requirement such as minimum communication range, latency, reliability, etc., adjusted with path loss PLb,f,cint(s,n) measured from all interference reference points (i.e. n=0, . . . N−1):
With a targeted power P0_PSDCH,b,f,c (i, n) for interference reference point n (n=0, . . . N−1) based on interference control to the interference reference point:
where the f may be a minimum function, maximum function, weighted average function, etc.
The MRB,b,f,cPSDCH, MRB,b,f,cPSCCHdisc, and MRB,b,f,cPSSCHdisc are dedicated discovery channel PSDCH, and shared discovery channel PSCCH and PSSCH frequency resource assignments in resource blocks respectively on BWP b of carrier f of cell c, which are scaled with 2μ where μ is a subcarrier space of a numerology.
The PO_PSDCH,b,f,c(i), PO_PSCCHdisc,b,f,c(i), and PO_PSSCHdisc,b,f,c(i) are dedicated discovery channel PSDCH, and shared discovery channel PSCCH and PSSCH target powers respectively at the receiver for a proximity range {circumflex over (R)}prox(i) of a V2X service on BWP b of carrier ƒ of cell c, where cell c may be a virtual “cell” in proximity if out of network coverage or a serving cell if under the network coverage. For example, the target power may be set per the minimum communication range for a V2X service, or per the maximum allowable interference to an interference reference point or per the maximum allowable interference to the interference reference points in the proximity.
The αPSDCH,b,f,cint(i, n), αPSCCHdisc,b,f,cint(i, n), and αPSSCHdisc,b,f,cint(i, n) are dedicated discovery channel PSDCH, and shared discovery channel PSCCH and PSSCH interference reference point path loss scaling factors respectively for a proximity range {circumflex over (R)}prox(i) of a V2X service on BWP b of carrier f of cell c, where cell c may be a virtual “cell” in proximity if out of network coverage or a serving cell if under the network coverage.
The PLb,f,cint(s, n) is the nth interference reference point path loss measured from a reference point on BWP b of carrier ƒ of cell c, where cell c may be a virtual “cell” in proximity if out of network coverage or a serving cell if under the network coverage. The reference points may be a gNB as illustrated in
For a proximity range {circumflex over (R)}prox(i) of a V2X service, the inband interference based path loss PLb,f,cint(s, n) may be scaled with αPSDCH,b,f,cint(i, n), αPSCCHdisc,b,f,cint(i, n), and αPSSCHdisc,b,f,cint(i, n) for dedicated discovery channel PSDCH, and shared discovery channel PSCCH and PSSCH respectively. For example, a value of 0.5 for αPSDCH,b,f,cint(i, n) may set the transmit power adjustment for PSDCH based on PLb,f,cint(s, n) measurement in half scale, e.g., less considering the inband interference; or a value of 1.0 for αPSDCH,b,f,cint(i, n) may set the transmit power adjustment for PSDCH based on PLb,f,cint(s, n) measurement in full scale, e.g., fully considering the inband interference.
The ηPSDCH,b,f,cint(i, n), ηPSCCHdis,b,f,cint(i, n), and ηPSSCHdisc,b,f,cint(i, n) are dedicated discovery channel PSDCH and shared discovery channel PSCCH and PSSCH total interference reference point path loss scaling factors respectively for a proximity range {circumflex over (R)}prox(i) of a V2X service from N interference reference points on BWP b of carrier f of cell c, where cell c may be a virtual “cell” in proximity if out of network coverage or a serving cell if under the network coverage. For example,
is for the total path loss averaged with the weighted or scaled path losses measured from N interference reference points.
The discoverable range may be highly related to the level of transmit power. The higher transmit power, the larger discoverable area in the proximity. For some advanced NR V2X services where fast discovery is required, an open-loop adjustable transmit power scheme is exemplified in
At step 0, pre-configuration or configuration: configure QoS, interference management, transmit power control parameters for discovery channel(s) by gNB if under network coverage (i.e. mode 1), or by RSU, a Lead, a synchronization source UE if out of network coverage (i.e. mode 2).
At step 1, path loss measurement (optional): measures the path loss from a reference point if inband interference control is used with SSB/CSI-RS/DMRS on DL or S-SSB/S-CSI-RS/S-DMRS on SL.
At step 2, initial transmit power: sets the initial transmit power P0PSDCH based on configuration described herein or inband interference control described herein or maximum transmit power.
At step 3, broadcasts the discovery request: broadcasts the discovery message with the initial transmit power in proximity, e.g., sidelink discovery request on PSDCH or PSCCHdisc & PSSCHdisc
A. One-Time Discovery
At step 4, response to discovery request: a receiving UE(s) sends sidelink discovery response on PSDCH or PSCCHdisc & PSSCHdisc with the transmit power determined by the measured RSRP of the S-DMRS of PSDCH, or PSCCH and PSSCH and the related transmit power configured or indicated with the discovery request message, as well as the reporting measured RSRP or sidelink path loss from the receiving UE to the transmitting UE.
OR
B. Discovery with Iterations
At step 5, timed out: receives no response till when the discovery response searching window ends or when the discovery response timer expires
At step 6, increase transmit power: adjusts the transmit power at kth (k>0) transmission occasion with power increment (k) for a proximity range {circumflex over (R)}prox(i) of a V2X service on beam j, where j is one of B beams for simultaneous multi-beam transmission, may be set as the follows.
If inband interference management is included in the TPC setting, then the adjusted transmit power for discovery channels may be set as the follows.
The PMAXdisc,f,c(i) is maximum allowable transmit power for discovery corresponding to a proximity range {circumflex over (R)}prox(i) of a V2X service.
The PPSDCH,b,f,c,jk-1(i, s), PPSCCH,b,f,c,jk-1(i, s) and PPSSCH,b,f,c,jk-1(i, s) are the transmit power at (k−1)th transmission occasion for discovery message carried on dedicated PSDCH, or on shared PSCCH and PSSCH respectively.
At step 7A, response to discovery request: sends sidelink discovery response on PSDCH or PSCCHdisc & PSSCHdisc with the transmit power determined by the measured RSRP of the S-DMRS of PSDCH, or PSCCH and PSSCH and the related transmit power configured or indicated with the discovery request message, as well as reporting the measured RSRP or sidelink path loss from the receiving UE to the transmitting UE.
OR
At step 7B, retransmit till end of discovery:
1) Waits for the discovery response till timed out;
2) Retransmits the discovery request message with increased power;
3) Waits for discovery response till discovery response timer expires; and
4) Ends discovery if reaches the maximum retransmissions or if discovery procedure timer expires.
For NR sidelink, the transmit power for broadcast message carried on PSCCH for short message, e.g., PPSCCH, and on PSSCH, e.g., PPSSCH, may be configured by the higher layer with different QoS requirements. For example, a set of {{circumflex over (P)}PSCCH(i, j), {circumflex over (P)}PSSCH(i, j)} may be configured corresponding to a proximity range {circumflex over (R)}prox(i) of a V2X service with transmission configuration/or transmit beam j (where/is one of B beams for simultaneous multi-beam transmission) as follows:
P
PSCCH,b,f,c(i,j)=Min{PCMAX,f,c,{circumflex over (P)}PSCCH,b,f,c(i,j)} dBm,
P
PSSCH,b,f,c(i,j)=min{PCMAX,f,c,{circumflex over (P)}PSSCH,b,f,c(i,j)} dBm.
TPC with Interference Management for Broadcast
If inband interference management is included in the open-loop transmit power control for broadcast channel(s), the path loss measured from N interference reference points, such as gNB if under the network coverage as shown in
Similar to the synchronization power control, the transmit power control with interference management may be generally described as the follows using PSSCH as an example.
With a targeted power P0_PSSCH, b,f,c (i) on the sidelink receiver based on QoS requirement such as minimum communication range, latency, reliability, etc., adjusted with path loss PLb,f,cint(s, n) measured from all interference reference points (i.e. n=0, . . . N−1):
With a targeted power P0_PSSCH,b,f,c (i, n) for interference reference point n (n=0, . . . N−1) based on interference control to the interference reference point:
where the f may be a minimum function, maximum function, weighted average function, etc.
The MRB,b,f,cPSCCH, and MRB,b,f,cPSSCH are PSCCH and PSSCH frequency resource assignments in resource blocks respectively on BWP b of carrier f of cell c, which are scaled with 2μ where μ is a subcarrier space of a numerology.
The PO_PSCCH,b,f,c(i, j) and PO
The αPSCCH,b,f,cint(i, n), and αPSSCH,b,f,cint(i, n) are PSCCH and PSSCH interference reference point path loss scaling factors respectively for a proximity range {circumflex over (R)}prox(i) of a V2X service on BWP b of carrier f of cell c, where cell c may be a virtual “cell” in proximity if out of network coverage or a serving cell if under the network coverage.
The PLb,f,cint(r, s) is the nth interference reference point path loss measured from a reference point on BWP b of carrier ƒ of cell c, where cell c may be a virtual “cell” in proximity if out of network coverage or a serving cell if under the network coverage. The reference points may be a gNB as illustrated in
For a proximity range {circumflex over (R)}prox(i) of a V2X service, the inband interference based path loss PLb,f,cint(r, s) may be scaled with αPSCCH,b,f,cint(i, n), and αPSSCH,b,f,cint(i, n) for PSCCH and PSSCH respectively. For example, a value of 0.5 for αPSSCH,b,f,cint(i, n) may set the transmit power adjustment for PSCCH based on PLb,f,cint(r, s) measurement in half scale, e.g., less considering the inband interference; or a value of 1.0 for αPSSCH,b,f,cint(i, n) may set the transmit power adjustment for PSCCH based on PLb,f,cint(r, s) measurement in full scale, e.g., fully considering the inband interference.
The ηPSCCH,b,f,cint(i, n), and ηPSSCH,b,f,cint(i, n) are PSCCH and PSSCH total interference reference point path loss scaling factors respectively for a proximity range {circumflex over (R)}prox(i) of a V2X service from N interference reference points on BWP b of carrier η of cell c, where cell c may be a virtual “cell” in proximity if out of network coverage or a serving cell if under the network coverage. For example,
is for the total path loss averaged with the weighted or scaled path losses measured from N interference reference points.
The instantaneous path loss on sidelink may vary due to radio channel fading. Hence, close-loop power control is necessary for more precise transmit power management to ensure required performance as well as avoiding unnecessary interference in the proximity. A high-level overview of the proposed closed-loop transmit power control procedure is depicted in
The initial transmit power control illustrated in
The closed-loop transmit power control illustrated in
At step 1, perform L1 RSRP measurements: for interference management, measure RSRP from the synchronization signals and/or reference signals which may be filtered with layer 2 or layer 3 filters, e.g. SS and/or DMRS of a SSB, or CSI-RS on downlink from a gNB if under the network coverage, or the S-SS and/or S-DMRS of a S-SSB, or S-CSI-RS on sidelink from an RSU, a proximity lead, a group lead or a synchronization source UE or S-CSI-RS on sidelink from UEs in proximity. Measure or receive sidelink RSRP for sidelink path loss, which may be filtered with layer 2 or layer 3 filters.
At step 2, send power control feedback: sends power control feedback to gNB on uplink if with network control, and/or on sidelink to an RSU, a proximity lead, a group lead, a synchronization source UE, or the paired UE on a sidelink. The feedback may be Power Headroom (PH) report to gNB if in NR V2X Mode 1, or to an RSU, a proximity lead, a group lead or a synchronization source UE if in NR V2X Mode 2, The feedback may also be the measured or filtered L1 RSRP or L1 transmit power control (TPC) command for a previously received signal or message on a sidelink, e.g., S-DMRS of a PSSCH or aperiodic S-CSI-RS.
At step 3, received sidelink RSRP or sidelink TPC for previous transmission? Check if an RSRP or TPC is received for the previously transmitted signal or message. If yes, go to step 4B; otherwise, go to step 4A.
At step 4A, no adjustment: keep the current transmit power level.
At step 4B, adjustment: increase or decrease the transmit power level based on the received sidelink RSRP or TPC.
At step 5, a new data available or retransmission? Check if a new data is ready for transmission or retransmission with previous data. If yes, go to step 6; otherwise go to step 1.
At step 6, transmit: transmit the new data or retransmit the previous data with the adjusted transmit power. Then go to step 1.
Sidelink Closed-Loop TPC for Unicast
Closed-loop transmit power control starts with an initial power level, e.g., at 0th transmission occasion, and then adjust the transmit power level for the following transmissions, e.g., kth transmission accession with k>0, based on the power control feedback information, for example the TPC instruction for increasing or decreasing the power with an absolution or accumulative adjustment.
For NR sidelink, the initial transmit power as an open-loop transmit power control, at 0th transmission accession, for Sidelink Channel State Information Reference Signal (S-CSI-RS), e.g., PSCSIRS0, Sidelink Control Information (SCI) carried on PSCCH, e.g., PPSCCH0. and sidelink control or data message carried on PSSCH, e.g., PPSSCH0, may be configured by the higher layer with different QoS requirements. For example, a set of {{circumflex over (P)}SCSIRS(i, j)}, {{circumflex over (P)}PSCCH(i, j)} and {{circumflex over (P)}PSSCH(i, j)} may be configured corresponding to a proximity range {circumflex over (R)}prox(i) of a V2X service with configuration j, where j is one of C configurations for different transmissions or transmission beams, as follows:
P
SCSIRS,b,f,c
0(i,j)=min{PCMAX,f,c,{circumflex over (P)}SCSIRS,b,f,c(i,j)} dBm,
P
PSCCH,b,f,c
0(i,j)=min{PCMAX,f,c,{circumflex over (P)}PSCCH,b,f,c(i,j)} dBm,
P
PSSCH,b,f,c
0(i,j)=min{PCMAX,f,c,{circumflex over (P)}PSSCH,b,f,c(i,j)} dBm.
Initial Transmit Power with Interference Management
If inband interference management is included in the transmit power control for S-CSI-RS, PSCCH and PSSCH, the path loss measured from N interference reference points, such as gNB or gNB-like RSU if under the network coverage as shown in
P
SCSIRS,b,f,c
0(i,j,r,s)=min{PCMAX,f,c(0),10·log10(2μ·MRE,b,f,cSCSIRS(0))+PO_SCSIRS,b,f,c(i,j)+αSCSIRS,b,f,c(i,j)·PLb,f,c(r)+ηSCSIRS,b,f,cint(i)Σn=0n=N-1αSCSIRS,b,f,cint(i,n)·PLb,f,cint(s,n)} dBm,
P
PSCCH,b,f,c
0(i,j,r,s)=min{PCMAX,f,c(0),10·log10(2μ·MRB,b,f,cPSCCH(0))+PO_PSCCH,b,f,c(i,j)+αPSCCH,b,f,c(i,j)·PLb,f,c(r)+ΔTF,b,f,c(0)+ΔF_PSCCH(F)+ηPSCCH,b,f,cint(i)Σn=0n=N-1αPSCCH,b,f,cint(i,n)·PLb,f,cint(s,n)} dBm,
P
PSSCH,b,f,c
0(i,j,r,s)=min{PCMAX,f,c(0),10·log10(2μ·MRB,b,f,cPSSCH(0))+PO_PSSCH,b,f,c(i,j)+αPSCCH,b,f,c(i,j)·PLb,f,c(r)+ΔTF,b,f,c(0)+ηPSSCH,b,f,cint(i)Σn=0n=N-1αPSSCH,b,f,cint(i,n)·PLb,f,cint(s,n)} dBm.
Similar to the synchronization power control, the transmit power control with interference management may be generally described as the follows using PSSCH as an example With a targeted power P0_PSSCH, b,f,c (i) on the sidelink receiver based on QoS requirement such as minimum communication range, latency, reliability, etc., adjusted with path loss PLb,f,cint(s, n) measured from all interference reference points (i.e. n=0, . . . N−1):
With a targeted power P0_PSSCH,b,f,c (i, n) for interference reference point n (n=0, . . . N−1) based on interference control to the interference reference point:
where the f may be a minimum function, maximum function, weighted average function, etc.
The MRB,b,f,cSCSIRS(0), MRB,b,f,cPSCCH(0), and MRB,b,f,cPSSCH(0) are S-CSI-RS,PSCCH and PSSCH initial frequency resource assignments in resource blocks respectively with configuration j, where j is one of C configurations for different transmissions or transmission beams, on BWP b of carrier f of cell c.
The PO_SCSIRS,b,f,c(i, j), PO_PSCCH,b,f,c(i, j), and PO
The αSCSIRS,b,f,c(i, j), αPSCCH,b,f,c(i, j), and αPSSCH,b,f,c(i, j) are S-CSI-RS, PSCCH and PSSCH path loss scaling factors respectively for a proximity range {circumflex over (R)}prox(i) of a V2X service with configuration j, where j is one of C configurations for different transmissions or transmission beams, on BWP b of carrier f of cell c, where cell c may be a virtual “cell” in proximity if out of network coverage or a serving cell if under the network coverage.
The PLb,f,c(r) is the sidelink path loss measured with a reference signal configuration r, as illustrated in
The ΔTF,b,f,c(0) is the initial power adjustment related to Modulation Coding Scheme (MCS) for PSCCH and PSSCH respectively.
The ΔF_PSCCH(F) is the power adjustment related to different format of PSCCH.
The αSCSIRS,b,f,cint(i, n), αPSCCH,b,f,cint(i, n), and αPSSCH,b,f,cint(i, n) are S-CSI-RS, PSCCH and PSSCH interference reference point path loss scaling factors respectively for a proximity range {circumflex over (R)}prox(i) of a V2X service on BWP b of carrier f of cell c, where cell c may be a virtual “cell” in proximity if out of network coverage or a serving cell if under the network coverage.
The PLb,f,cint(s, n) is the nth interference reference point path loss measured from a reference point on BWP b of carrier f of cell c, where cell c may be a virtual “cell” in proximity if out of network coverage or a serving cell if under the network coverage. The reference points may be a gNB as illustrated in
For a proximity range {circumflex over (R)}prox(i) of a V2X service, the inband interference based path loss PLb,f,cint(s, n) may be scaled with αSCSIRS,b,f,c(i, j), αPSCCH,b,f,c(i, j), and αPSSCH,b,f,c(i, j) for S-CSI-RS, PSCCH and PSSCH respectively. For example, a value of 0.5 for αPSCCH,b,f,cint(i, n) may set the transmit power adjustment for PSCCH based on PLb,f,cint(s, n) measurement in half scale, e.g., less considering the inband interference; or a value of 1.0 for αPSCCH,b,f,cint(i, n) may set the transmit power adjustment for PSCCH based on PLb,f,cint(s, n) measurement in full scale, e.g., fully considering the inband interference.
The ηSCSIRS,b,f,cint(i, n), ηPSCCH,b,f,cint(i, n), and ηPSSCH,b,f,cint(i, n) are S-CSI-RS, PSCCH and PSSCH total interference reference point path loss scaling factors respectively for a proximity range {circumflex over (R)}prox(i) of a V2X service from an interference reference point n on BWP b of carrier f of cell c, where cell c may be a virtual “cell” in proximity if out of network coverage or a serving cell if under the network coverage. For example,
is for the total path loss averaged with the weighted or scaled path losses measured from N interference reference points.
Closed-loop TPC may be conducted based on the power control feedback, e.g., the sidelink RSRP or TPC instruction. The closed-loop transmit power of unicast with PSCCH and PSSCH at kth (k>0) transmission occasion for a proximity range {circumflex over (R)}prox(i) of a V2X service with configuration j, where j is one of C configurations for different transmissions messages or transmission modes or transmission beams, may be set as follows with the TPC feedback.
Similar to the synchronization power control, the transmit power control with interference management may be generally described as the follows using PSSCH as an example. With a targeted power P0_PSSCH, b,f,c (i) on the sidelink receiver based on QoS requirement such as minimum communication range, latency, reliability, etc., adjusted with path loss PLb,f,cint(s,n) measured from all interference reference points (i.e. n=0, . . . N−1):
With a targeted power P0_PSSCH,b,f,c (i, n) for interference reference point n (n=0, . . . N−1) based on interference control to the interference reference point:
where the f may be a minimum function, maximum function, weighted average function, etc.
The MRB,b,f,cSCSIRS(k), MRB,b,f,cPSCCH(k), and MRB,b,f,cPSSCH(k) are S-CSI-RS,PSCCH and PSSCH frequency resource assignments in resource blocks respectively at kth transmission occasion with configuration j, where j is one of C configurations for different transmissions or transmission beams, on BWP b of carrier f of cell c.
The ΔTF,b,f,c(k) is the power adjustment at kth transmission occasion related to MCS for PSCCH and PSSCH respectively.
The fb,f,c (k, l) is the closed-loop power control adjustment state at kth transmission occasion for power control loop l or power control loop configuration l. For accumulated closed-loop power adjustment, the fb,f,c(k, l) may be calculated for S-CSI-RS, PSCCH, and PSSCH respectively with the following equations as an example.
f
b,f,c(k,l)=fb,f,c(k−k0,l)+Σp=0p=Γ-1δSCSIRS,b,f,c(p,l),
f
b,f,c(k,l)=fb,f,c(k−k0,l)+Σp=0p=Γ-1δPSCCH,b,f,c(p,l),
f
b,f,c(k,l)=fb,f,c(k−k0,l)+Σp=0p=Γ-1δPSSCH,b,f,c(p,l),
where
Closed-loop TPC procedures are exemplified in this section.
As depicted in
At step 0A, pre-configuration or configuration: gNB or gNB-like RSU configures unicast ID(s), resource pool(s), transmission mode, path loss measuring, power control parameters, etc.
At step 0B, unicast configuration: UE1 updates resource pool(s), transmission mode, transmission occasions, path loss measuring RS, power control parameters, etc., via discovery and pairing between UE1 & UE2.
At step 1, interference path loss measurement (optional): optional if inband interference control is used. UE1 measures the DL path loss, using the PSS/SSS and/or DMRS of PBCH within SSB(s) or the CSI-RS from gNB or gNB-like RSU.
At step 2, sidelink path loss measurement: UE1 measures the path loss from the SL reference signal(s) such as S-PSS/S-SSS and/or S-DMRS of PSBCH within S-SSB(s) or S-CSI-RS or S-DMRS from UE2 or receives the path loss from UE2 of from the SL reference signal(s) such as S-PSS/S-SSS and/or S-DMRS of PSBCH within S-SSB(s) or S-CSI-RS or S-DMRS from UE1 respectively.
At step 3, schedule initial transmission with DCI (optional): optional for dynamically scheduled transmission. gNB sends sidelink schedule to UE1 only or both UE1 and UE2 with DCI(s) which may contain resource allocation, MSC, HARQ, TPC, etc.
At step 4, initial transmit power: UE1 sets the initial transmit power P° with interference or not as configured (e.g., RRC configuration) or indicated (e.g., DCI scheduling the transmission) by gNB.
At step 5, initial transmission: UE1 sends the initial transmission with PSSCH or PSDCCH and PSSCH at the initial transmit power P°.
At step 6, set transmit power for ACK/NACK: UE2 decodes the received message and calculates the transmit power for sending ACK/NACK feedback on SL to UE1 or on Uu to gNB.
For the ACK/NACK feedback on SL, UE2 may use channel reciprocal property to calculate the transmit power for ACK/NACK on SL Carried by for example PSFCH (Physical Sidelink Feedback Channel). For example, UE2 may set the feedback transmit power with UE1's initial transmit power, as indicated in the initial transmission or as configured during the pairing, adjusted with the measured RSRP, with the power adjustment indicated in RSRP or TPC on the feedback to UE1 if retransmission is needed. If the feedback requires larger communication range, the transmit power level for feedback may be based on one of configured values based on the QoS such as communication range, reliability, latency, receiving UE's location or transmitting UE and receiving UE's distance, etc., adjusted on the measured RSRP with the received PSSCH with an adjustment such as power boosting, interference control, etc.
Step 7A or Step 7B1 and 7B2.
At step 7A, ACK/NACK for retransmission: UE2 sends ACK/NACK feedback to UE1. If NACK, the retransmission settings such as resource allocation, MCS, HARQ, TPC, etc., may be included.
At step 7B1, ACK/NACK for retransmission: UE2 sends ACK/NACK feedback to gNB with UL transmit power setting as configured (e.g., RRC configuration) or indicated (e.g., DCI for the initial transmission) by gNB.
At step 7B2, schedule retransmission with DCI (optional): optional if dynamically scheduling the retransmission. The gNB schedules the retransmission on sidelink with DCI(s) containing resource allocation, MCS, HARQ, TPC, etc. to UE1 or to both UE1 and UE2
At step 8, adjust transmit power if NACK: UE1 adjusts the closed-loop transmit power per sidelink RSRP or TPC feedback from UE2, or per TPC indicated in the DCI for retransmission from gNB.
At step 9, retransmission: UE1 sends retransmission to UE2 with PSSCH or PSDCCH and PSSCH at the adjusted transmit power.
As depicted in
At step 0A, pre-configuration or configuration: RSU, proximity lead, group lead or synchronization source UE configures unicast ID(s), resource pool(s), transmission mode, path loss measuring, power control parameters, etc.
At step 0B, unicast configuration: UE1 updates resource pool(s), transmission mode, transmission occasions, path loss measuring RS, power control parameters, etc., via discovery and pairing between UE1 & UE2.
At step 1, interference path loss measurement (optional): optional if inband interference control is used. UE1 measures the interference path loss, using the S-PSS/S-SSS and/or S-DMRS of PSBCH within S-SSB(s) or the S-CSI-RS on SL1 from RSU, proximity lead, group lead or synchronization source UE.
At step 2, sidelink path loss measurement: UE1 measures the path loss from the sidelink signal(s) such as S-PSSS/S-SSS and/or S-DMRS of PSBCH within S-SSB(s) or S-CSI-RS on SL2 from UE2, or receives the path loss from UE2 based on a previous transmission
At step 3, schedule initial transmission with DCI (optional): optional for dynamically scheduled transmission. RSU, proximity lead, group lead or synchronization source UE sends sidelink schedule to UE1 only or both UE1 and UE2 with SCI(s) which may contain resource allocation, MSC, HARQ, TPC, etc.
At step 4, initial transmit power: UE1 sets the initial transmit power P0 with interference or not as configured (e.g., via pairing) or indicated (e.g., SCI scheduling the transmission) by RSU, proximity lead, group lead or synchronization source UE.
At step 5, initial transmission: UE1 sends the initial transmission with PSSCH or PSDCCH and PSSCH at the initial transmit power P0 to UE2 on SL2.
At step 6, set transmit power for ACK/NACK: UE2 decodes the received message and calculates the transmit power for sending Sidelink Feedback Control Information (SFCI) containing ACK/NACK feedback on SL2 to UE1 or on SL1 to RSU, proximity lead, group lead or synchronization source UE.
For the ACK/NACK feedback on SL2, UE2 may use channel reciprocal property to calculate the transmit power for ACK/NACK on SL2. For example, UE2 may set the feedback transmit power with UE1's initial transmit power, as indicated in the initial transmission or as configured during the pairing, adjusted with the measured RSRP with or without power boosting which may be configured by RRC or SL-RRC or indicated by SL-MAC CE or SCI, with the power adjustment feedback indicated in RSRP or TPC on a feedback channel, such as PSSCH, to UE1 if retransmission is needed. If the feedback requires larger communication range, the transmit power level for feedback may be based on one of configured values based on the QoS such as communication range, reliability, latency, receiving UE's location or transmitting UE and receiving UE's distance, etc., and/or adjusted with the measured RSRP of the received PSSCH with an adjustment such as power boosting. The transmit power control may also use the scheme proposed for broadcast message transmit power control with or without interference control as described previously.
Step 7A or Step 7B1 and 7B2.
At step 7A, ACK/NACK for retransmission: UE2 sends SFCI containing ACK/NACK feedback on SL2 to UE1. If NACK, the retransmission settings such as resource allocation, MSC, HARQ, TPC, etc., may be included in SFCI or SCI.
At step 7B1, ACK/NACK for retransmission: UE2 sends SFCI containing ACK/NACK feedback on SL1 to RSU, proximity lead, group lead or synchronization source UE with sidelink transmit power setting as configured (e.g., via pairing) or indicated (e.g., SCI for the initial transmission) by RSU, proximity lead, group lead or synchronization source UE, or with the sidelink transmit power setting by using sidelink transmit power control scheme similar to the transmit power setting on SL2.
At step 7B2, schedule retransmission with DCI (optional): optional if dynamically scheduling the retransmission on SL. The RSU, proximity lead, group lead or synchronization source UE schedules the retransmission on SL2 with SCI(s) containing resource allocation, MSC, HARQ, TPC, etc. to UE1 or to both UE1 and UE2
At step 8, adjust transmit power if NACK: UE1 adjusts the closed-loop transmit power per RSRP or TPC feedback from UE2's SFCI on SL2, or per RSRP or TPC indicated in the SCI for retransmission from RSU, proximity lead, group lead or synchronization source UE on SL1.
At step 9, retransmission: if a NACK was received in Step 7A/B1.B2, UE1 sends retransmission to UE2 on SL2 with PSSCH or PSDCCH and PSSCH at the adjusted transmit power.
Sidelink Closed-Loop TPC for Groupcast
Closed-loop transmit power control starts with an initial power level, e.g., at 0th transmission occasion, for certain QoS requirement for a multicast or groupcast, and then adjust the transmit power level for the following transmissions, e.g., at kth (k>0) transmission occasion, based on the power control feedback information from UE(s) within the group, e.g., the TPC instructions for increasing or decreasing the power with an absolution or accumulative adjustment.
For NR sidelink groupcast or multicast, the initial transmit power as an open-loop transmit power control for sidelink reference signal S-CSI-RS, e.g., PSCSIRSgp0, Sidelink Control Information (SCI) carried on PSCCH, e.g., PPSCCHgp0, and sidelink control or data carried on PSSCH, e.g., PPSSCHgp0, may be configured by the higher layer with different QoS requirements. For example, a set of {{circumflex over (P)}SCSIRSgp(i, j)}, {{circumflex over (P)}PSCCHgp(i, j)} and {{circumflex over (P)}PSSCHgp(i, j)} may be configured corresponding to a proximity range {circumflex over (R)}prox(i) of a group with configuration j, where j is one of C configurations for different transmissions or transmission beams, as follows:
P
SCSIRSgp,b,f,c
0(i,j)=min{PCMAX,f,c,{circumflex over (P)}SCSIRSgp,b,f,c(i,j)} dBm,
P
PSCCHgp,b,f,c
0(i,j)=min{PCMAX,f,c,{circumflex over (P)}PSCCHgp,b,f,c(i,j)} dBm,
P
PSSCHgp,b,f,c
0(i,j)=min{PCMAX,f,c,{circumflex over (P)}PSSCHgp,b,f,c(i,j)} dBm.
Initial Transmit Power with Interference Management
If inband interference management is included in the transmit power control for S-CSI-RS, PSCCH and PSSCH, the path loss measured from N interference reference points, such as gNB if under the network coverage as shown in
Similar to the synchronization power control, the transmit power control with interference management may be generally described as the follows using PSSCH as an example. With a targeted power P0_PSSCH, b,f,c (i) on the sidelink receiver based on QoS requirement such as minimum communication range, latency, reliability, etc., adjusted with path loss PLb,f,cint(s,n) measured from all interference reference points (i.e. n=0, . . . N−1):
With a targeted power P0_PSSCH,b,f,c (i, n) for interference reference point n (n=0, . . . N−1) based on interference control to the interference reference point:
where the f may be a minimum function, maximum function, weighted average function, etc.
The MRB,b,f,cSCSIRS(0), MRB,b,f,cPSCCH(0), and MRB,b,f,cPSSCH(0) are S-CSI-RS,PSCCH and PSSCH initial frequency resource assignments in resource blocks respectively with configuration j, where j is one of C configurations for different transmissions or transmission beams, on BWP b of carrier f of cell c.
The PO_SCSIRSgp,b,f,c(i, j), PO_PSCCHgp,b,f,c(i, j) and PO
P
O_SCSIRSgp,b,f,c(i,j)=PO_NOMINAL_SCSIRSgp,b,f,c(i,j)+PO_UE_SCSIRSgp,b,f,c(i,j),
P
O_PSCCHgp,b,f,c(i,j)=PO_NOMINAL_PSCCHgp,b,f,c(i,j)+PO_UE_PSCCHgp,b,f,c(i,j),
P
O_PSSCHgp,b,f,c(i,j)=PO_NOMINAL_PSSCHgp,b,f,c(i,j)+PO_UE_PSSCHgp,b,f,c(i,j),
where:
PO_NOMINAL_SCSIRSgp,b,f,c(i, j), PO_NOMINAL_PSCCHgp,b,f,c(i, j), and PO_NOMINAL_PSSCHgp,b,f,c(i, j) may be configured per the priority, reliability, latency and minimum service range requirement for a V2X group with proximity range of range {circumflex over (R)}prox(i) and transmission configuration or transmit beam configuration j for S-CSI-RS, PSCCH and PSSCH respectively, and
PO_UE_SCSIRSgp,b,f,c(i, j), PO_UE_PSCCHgp,b,f,c(i, j), and PO_UE_PSSCHgp,b,f,c(i, j) are configured for UE specific component of a V2X group with proximity range of range {circumflex over (R)}prox(i) and transmission configuration or transmit beam configuration j for S-CSI-RS, PSCCH and PSSCH respectively. For example, the PO_UE_PSSCHgp,b,f,c(i, j) may be set differently with different reliability requirements for a groupcast or multicast, e.g., targeting to the worst, average, or best UE reception within the group based on UEs' locations within a group's proximity or on UEs' radio link quality measured from the measuring signals from the UEs within the group. For another example, PO_UE_PSSCHgp,b,f,c(i, j) may be set differently with different latency requirements such as guaranteed service to all UEs in the group to minimize averaged delay caused by retransmissions or best effort service to most UEs in the group to allow certain level of averaged delay caused by retransmission.
The αSCSIRSgp,b,f,c(i, j, q), αPSCCHgp,b,f,c(i, j, q), and αPSSCHgp,b,f,c(i, j, q) are S-CSI-RS, PSCCH and PSSCH qth (0<q<Q) path loss scaling factors respectively for a proximity range {circumflex over (R)}prox(i) of a V2X service with configuration j, where j is one of C configurations for different transmissions or transmission beams, on BWP b of carrier f of cell c, where cell c may be a virtual “cell” in proximity if out of network coverage or a serving cell if under the network coverage.
The PLb,f,c(r, q) is the sidelink qth (0≤q<Q) path loss measured from qth sidelink of total Q sidelinks, where Q may be a integer value smaller or equal to the total member UEs of a group, within a group for path loss measurement, with a reference signal configuration r, as illustrated in
The
are function of scaled path loss measured on total Q sidelinks within a group for S-CSI-RS, PSCCH and PSSCH respectively. For example, the function may be one of the follows based on the QoS requirements such as service range, reliability, latency, etc., using PSSCH as an example below.
for the least path loss compensation within the group, e.g., for the best UE's radio link among the UEs within the group;
for the most path loss compensation within the group, e.g., for the worst UE's radio link among the UEs within the group;
for scaled or weighted average path loss compensation among the UEs within the group.
The ΔTF,b,f,c(0) is the initial power adjustment related to Modulation Coding Scheme (MCS) for PSCCH and PSSCH respectively.
The ΔF_PSCCH(F) is the power adjustment related to different format of PSCCH.
The αSCSIRS,b,f,cint(i, n), αPSCCH,b,f,cint(i, n), and αPSSCH,b,f,cint(i, n) are S-CSI-RS, PSCCH and PSSCH interference reference point path loss scaling factors respectively for a proximity range {circumflex over (R)}prox(i) of a V2X service on BWP b of carrier f of cell c, where cell c may be a virtual “cell” in proximity if out of network coverage or a serving cell if under the network coverage.
The PLb,f,cint(s, n) is the nth interference reference point path loss measured from a reference point on BWP b of carrier f of cell c, where cell c may be a virtual “cell” in proximity if out of network coverage or a serving cell if under the network coverage. The reference points may be a gNB as illustrated in
The ηSCSIRS,b,f,cint(i, n), ηPSCCH,b,f,cint(i, n), and ηPSSCH,b,f,cint(i, n) are S-CSI-RS, PSCCH and PSSCH total interference reference point path loss scaling factors respectively for a proximity range {circumflex over (R)}prox(i) of a V2X service from N interference reference points on BWP b of carrier f of cell c, where cell c may be a virtual “cell” in proximity if out of network coverage or a serving cell if under the network coverage. For example,
is for the total path loss averaged with the weighted or scaled path losses measured from N interference reference points.
Closed-loop TPC may be conducted based on the power control feedbacks from UEs within a group, e.g., the TPC instructions from some or all UEs of a group. The closed-loop transmit power of groupcast or multicast with S-CSI-RS, PSCCH and PSSCH at kth occasion for a proximity range {circumflex over (R)}prox(i) of a V2X service with configuration j, where j is one of C configurations for different transmissions messages or transmission modes or transmission beams, may be set as follows with the TPC feedback q∈[0, Q).
Similar to the synchronization power control, the transmit power control with interference management may be generally described as the follows using PSSCH as an example. With a targeted power P0_PSSCH, b,f,c (i) on the sidelink receiver based on QoS requirement such as minimum communication range, latency, reliability, etc., adjusted with path loss PLb,f,cint(s,n) measured from all interference reference points (i.e. n=0, . . . N−1):
With a targeted power P0_PSSCH,b,f,c (i, n) for interference reference point n (n=0, . . . N−1) based on interference control to the interference reference point
where the f may be a minimum function, maximum function, weighted average function, etc.,
The MRB,b,f,cSCSIRS(k), MRB,b,f,cPSCCH(k), and MRB,b,f,cPSSCH(k) are S-CSI-RS,PSCCH and PSSCH frequency resource assignments in resource blocks respectively at kth transmission occasion with configuration j, where j is one of C configurations for different transmissions or transmission beams, on BWP b of carrier f of cell c.
The ΔTF,b,f,c(k) is the power adjustment at kth transmission occasion related to MCS for PSCCH and PSSCH respectively.
The {tilde over (f)}gp,b,f,c(k,l, q)|q∈[0,Q) is the closed-loop power control adjustment state at kth transmission occasion with total Q TPC feedback, e.g., q∈[0, Q), for power control loop l or power control loop configuration l. For accumulated closed-loop power adjustment, the {tilde over (f)}gp,b,f,c(k, l, q)|q∈[0,Q) may be calculated for S-CSI-RS, PSCCH, and PSSCH respectively with the following equations as an example.
For S-CSI-RS:
{tilde over (f)}SCSIRSgp,b,f,c(k−k0, l, q)|q∈[0,Q) is the closed-loop power control adjustment state at (k−k0)th transmission occasion for power control loop l or power control loop configuration l;
are accumulated total of Γ TPC command values derived (e.g., least adjustment, most adjustment, or averaged adjustment respectively.) from total Q TPC feedbacks on from Q UEs within a group between transmission occasion k−k0 and k for power control loop l or power control loop configuration l.
For PSCCH:
for least power adjustment,
for most power adjustment, and
for averaged power adjustment.
For PSSCH:
for least power adjustment,
for most power adjustment, and
Closed-loop TPC procedures for groupcast or multicast are exemplified in this section.
As depicted in
At step 0A, Pre-configuration or configuration: configures groupcast or multicast ID(s), resource pool(s), transmission mode, path loss measuring, power control parameters per group service range, reliability, latency, etc.
At step 0B, Groupcast or multicast configuration: updates resource pool(s), transmission mode, transmission occasions, path loss measuring sidelinks and related RSs, power control parameters, etc., via discovery and joining the group.
At step 1, Interference path loss measurement (optional): optional if inband interference control is used. UE0 measures the DL path loss, using the PSS/SSS and/or DMRS of PBCH within SSB(s) or the CSI-RS from gNB or gNB-like RSU.
At step 2, Sidelink path loss measurement: measures the path loss from the SL reference signal(s) on Q−1 sidelinks within the group.
At step 3, Schedule initial transmission with DCI (optional): optional for dynamically scheduled transmission. gNB sends sidelink schedule to UE0 only or both UE0 and UE1˜UEQ-1 within the group with DCI(s) which may contain resource allocation, MCS, HARQ, TPC, etc.
At step 4, Initial transmit power: UE0 sets the initial transmit power P0 with interference or not as configured (e.g., RRC configuration) or indicated (e.g., DCI scheduling the transmission) by gNB.
At step 5, Initial transmission: UE0 groupcasts or multicasts the initial transmission with PSSCH or PSDCCH and PSSCH at the initial transmit power P0.
At step 6, Set transmit power for ACK/NACK: UE1˜UEQ-1 decodes the received message with ACK or NACK and calculates the transmit power for sending ACK/NACK feedback on SL to UE0 or on UL to gNB.
For the ACK/NACK feedback on SL, UE1˜UEQ-1 may use channel reciprocal property to calculate the transmit power for ACK/NACK on SL. For example, UE1˜UEQ-1 may set the feedback transmit power with UE0's initial transmit power, as indicated in the initial transmission or as configured during joining the group, adjusted with its measured RSRP, with the power adjustment indicated in RSRP or TPC on the feedback carried on SFCIs to UE0. If the feedback requires larger communication range, the transmit power level for feedback may be based on one of configured values based on the QoS such as communication range, reliability, latency, receiving UE's location or transmitting UE and receiving UE's distance, etc., and/or adjusted with the measured RSRP of the received PSSCH with an adjustment such as power boosting. The transmit power control may also use the scheme proposed for broadcast message transmit power control with or without interference control as described previously.
Step 7A or Step 7B1 and 7B2.
At step 7A, Sidelink ACK/NACK from UE1˜UEQ-1: UE1˜UEQ-1 send ACK/NACK feedbacks to UE0. If NACK, the retransmission settings such as resource allocation, MCS, HARQ, TPC, etc., may be included on the SFCI or SCI.
At step 7B1, ACK/NACK for retransmission UE1˜UEQ-1 send ACK/NACK feedbacks to gNB with UL transmit power setting as configured (e.g., RRC configuration) or indicated (e.g., DCI for the initial transmission) by gNB.
At step 7B2, Schedule retransmission with DCI (optional): optional if dynamically scheduling the retransmission. The gNB schedules the retransmission on sidelink with DCI(s) containing resource allocation, MCS, HARQ, TPC, etc. to UE0 or to UE0˜UEQ-1.
At step 8, Adjust transmit power if NACK: UE0 adjusts the closed-loop transmit power per TPC feedbacks from UE0˜UEQ-1, or per TPC indicated in the DCI for retransmission from gNB.
At step 9, Retransmission: UE0 sends retransmission groupcasting or multicasting to UE0˜UEQ-1 with PSSCH or PSDCCH and PSSCH at the adjusted transmit power.
As depicted in
At step 0A, Pre-configuration or configuration: RSU, proximity lead, group lead or synchronization source UE configures groupcast or multicast ID(s), resource pool(s), transmission mode, path loss measuring, power control parameters per group service range, reliability, latency, etc.
At step 0B, Groupcast or multicast configuration: UE0 updates resource pool(s), transmission mode, transmission occasions, path loss measuring sidelinks and related RSs, power control parameters, etc., via discovery and joining the group.
At step 1, Interference path loss measurement (optional): optional if inband interference control is used. UE0 measures the sidelink path loss on SL0, using the S-PSS/S-SSS and/or S-DMRS of PSBCH within S-SSB(s) or the S-CSI-RS from RSU, proximity lead, group lead or synchronization source UE.
At step 2, Sidelink path loss measurement: measures the path loss from the SL reference signal(s) on Q−1 sidelinks within the group.
At step 3, Schedule initial transmission with DCI (optional): optional for dynamically scheduled transmission. RSU, proximity lead, group lead or synchronization source UE sends sidelink schedule to UE0 only or UE0˜UEQ-1 within the group with SCI(s) which may contain resource allocation, MCS, HARQ, TPC, etc.
At step 4, Initial transmit power: UE0 sets the initial transmit power P0 with interference or not as configured (e.g., via joining the group) or indicated (e.g., SCI scheduling the transmission) by RSU, proximity lead, group lead or synchronization source UE.
At step 5, Initial transmission: UE0 groupcasts or multicasts the initial transmission with PSSCH or PSDCCH and PSSCH at the initial transmit power P0.
At step 6, Set transmit power for ACK/NACK: UE1˜UEQ-1 decodes the received message with ACK or NACK and calculates the transmit power for sending ACK/NACK feedbacks carried by SFCI or SCI on SL to UE0 or on SL to RSU, proximity lead, group lead or synchronization source UE.
For the ACK/NACK feedbacks on SL, UE1˜UEQ-1 may use channel reciprocal property to calculate the transmit power for ACK/NACK on SL. For example, UE1˜UEQ-1 may set the feedback transmit power with UE0 's initial transmit power, as indicated in the initial transmission or as configured during joining the group, with the power adjustment indicated in the TPC on the feedback carried on SFCIs or SCIs to UE0.
Step 7A or Step 7B1 and 7B2.
At step 7A, Sidelink ACK/NACK from UE1˜UEQ-1: UE1˜UEQ-1 send ACK/NACK feedbacks to UE0. If NACK, the retransmission settings such as resource allocation, MCS, HARQ, TPC, etc., may be included on the SFCI or SCI.
At step 7B1, ACK/NACK for retransmission: UE1˜UEQ-1 send ACK/NACK feedbacks to RSU, proximity lead, group lead or synchronization source UE with SL transmit power setting as configured (e.g., via joining the group) or indicated (e.g., SCI for the initial transmission) by RSU, proximity lead, group lead or synchronization source UE or with the sidelink transmit power setting by using sidelink transmit power control scheme similar to the transmit power setting on SL1˜SLQ−1.
At step 7B2, Schedule retransmission with SCI (optional): optional if dynamically scheduling the retransmission. The RSU, proximity lead, group lead or synchronization source UE schedules the retransmission on sidelink with SCI(s) containing resource allocation, MCS, HARQ, TPC, etc. to UE0 only or to UE0˜UEQ-1.
At step 8, Adjust transmit power if NACK: UE0 adjusts the closed-loop transmit power per TPC feedbacks from UE0˜UEQ-1, or per TPC indicated in the SCI for retransmission from RSU, proximity lead, group lead or synchronization source UE.
At step 9, Retransmission: UE0 sends retransmission groupcast data or multicast data to UE0˜UEQ-1 with PSSCH or PSDCCH and PSSCH at the adjusted transmit power.
At Uu interface, a NR system supports different data communications with different services such as enhanced Mobile Broadband (eMBB), Ultra-Reliable Low-Latency Communications (URLLC) and massive Machine Type Communications (mMTC). At PC5 interface, NR V2X supports more diverse communications such as unicast, groupcast and broadcast with periodic or aperiodic traffic with small or large data, and many of these communications require high reliability and low latency like URLLC.
A UE may be configured or scheduled with an uplink (UL) transmission overlapping in time with a sidelink (SL) transmission. As illustrated in
A UE may also be configured or scheduled with a SL transmission overlapping in time with another SL transmission. As illustrated in
With the overlapped transmissions, if the total transmit power exceeds the maximum allowed transmit power, simply dropping a transmission may fail the reliability or latency requirement for services such as URLLC on Uu interface and emergency maneuver exchange on PC5 interface.
As exemplified in
At step 1, UL & SL overlapping, a UE is scheduled or configured an UL transmission with priority PUL and a SL transmission with priority PSL.
At step 2, check if “PowerUL+PowerSL>PowerMax?”: If the total power of UL and SL exceeds the maximum allowed transmit power, move to step 4; otherwise, move to step 3.
At step 3, transmit independently: transmit both UL and SL with required power PowerUL and PowerSL respectively.
At step 4, check if “PUL or PSL allows to drop?”: if yes, move to step 5; otherwise, move to step 6.
At step 5, drop one: drop the one allowed and transmit the other one.
At step 6, check if “both PUL & PSL allow to drop?”: if yes, move to step 7; otherwise, move to step 8.
At step 7, drop one: compare the priority between PUL and PSL, drop the one with lower priority and transmit the other; or randomly drop one and transmit the other if the same priority with PUL and PSL2.
At step 8, power scaling: compare the priority level between PUL and PSL and scale down the power per priority, e.g. higher priority less scaling down or lower priority more scaling down; if extra SL resources are available, adjust MCS (e.g. lower the modulation) or insert repetition, indicate the adjusted MCS or repetition in the SCI associated with the SL transmission; transmit both UL and SL with scaled power level respectively.
As exemplified in
At step 1, SL & SL overlapping: a UE is scheduled or configured one SL transmission with priority PSL1 and another SL transmission with priority PSL2.
At step 2, check if “PowerSL1+PowerSL2>PowerMax?”: If the total power of SL 1 and SL 2 exceeds the maximum allowed transmit power, move to step 4; otherwise, move to step 3.
At step 3, transmit independently: transmit both SL1 and SL2 with required power PowerSL1 and PowerSL2 respectively.
At step 4, check if “PSL1 or PSL2 allows to drop?”: if yes, move to step 5; otherwise, move to step 6.
At step 5, drop one: drop the one allowed and transmit the other one.
At step 6, check if “both PSL1 & PSL2 allow to drop?”: if yes, move to step 7; otherwise, move to step 8.
At step 7, drop one: compare the priority level between PSL1 and PSL2, drop the one with lower priority and transmit the other; or randomly drop one and transmit the other if the same priority with PSL1 or PSL2.
At step 8, power scaling: compare the priority level with PUL or PSL and scale down the power per priority, e.g. higher priority less scaling down or lower priority more scaling down; if extra SL resources are available, adjust MCS (e.g. lower the modulation) or insert repetition, indicate the adjusted MCS or repetition in the SCI associated with the SL transmission; transmit both SL1 and SL2 with the scaled power and the associated SCIs.
This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.
This application claims the benefit of priority to U.S. Application No. 62/757,431, filed on 8 Nov. 2018, the entirety of which is incorporated by reference herein.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2019/050596 | 9/11/2019 | WO | 00 |
| Number | Date | Country | |
|---|---|---|---|
| 62757431 | Nov 2018 | US |
