PHYSICAL SIDELINK CONTROL CHANNEL (PSCCH) SIGNALING FOR MULTIPLE TRANSMISSION TIME INTERVAL (TTI) TRANSMISSIONS

Abstract

An apparatus for use in a UE includes processing circuitry coupled to a memory. To configure the UE for 5G-NR sidelink communications, the processing circuitry is to decode sidelink control information (SCI) received from a second UE via a physical sidelink control channel (PSCCH). The SCI indicates sidelink resources for transmission of a transport block during multiple transmission time intervals. A frequency resource assignment and a time resource assignment for the multiple transmission time intervals are determined based on the sidelink resources. A physical sidelink shared channel (PSSCH) is decoded, the PSSCH including the transport block, and received in one of the multiple transmission time intervals using the frequency resource assignment and the time resource assignment.

Description

TECHNICAL FIELD

Aspects pertain to wireless communications. Some aspects relate to wireless networks including 3GPP (Third Generation Partnership Project) networks, 3GPP LTE (Long Term Evolution) networks, 3GPP LTE-A (LTE Advanced) networks, and fifth-generation (5G) networks including 5G new radio (NR) (or 5G-NR) networks and 5G-LTE networks such as 5GNR unlicensed spectrum (NR-U) networks. Other aspects are directed to systems and methods for physical sidelink control channel (PSCCH) signaling for multiple transmission time interval (TTI) transmissions.

BACKGROUND

Mobile communications have evolved significantly from early voice systems to today's highly sophisticated integrated communication platform. With the increase in different types of devices communicating with various network devices, usage of 3GPP LTE systems has increased. The penetration of mobile devices (user equipment or UEs) in modern society has continued to drive demand for a wide variety of networked devices in many disparate environments. Fifth-generation (5G) wireless systems are forthcoming and are expected to enable even greater speed, connectivity, and usability. Next generation 5G networks (or NR networks) are expected to increase throughput, coverage, and robustness and reduce latency and operational and capital expenditures. 5G-NR networks will continue to evolve based on 3GPP LTE-Advanced with additional potential new radio access technologies (RATs) to enrich people's lives with seamless wireless connectivity solutions delivering fast, rich content and services. As current cellular network frequency is saturated, higher frequencies, such as millimeter wave (mmWave) frequency, can be beneficial due to their high bandwidth.

Potential LTE operation in the unlicensed spectrum includes (and is not limited to) the LTE operation in the unlicensed spectrum via dual connectivity (DC), or DC-based LAA, and the standalone LTE system in the unlicensed spectrum, according to which LTE-based technology solely operates in the unlicensed spectrum without requiring an “anchor” in the licensed spectrum, called MulteFire. MulteFire combines the performance benefits of LTE technology with the simplicity of Wi-Fi-like deployments.

Further enhanced operation of LTE systems in the licensed as well as unlicensed spectrum is expected in future releases and 5G systems. Such enhanced operations can include techniques for PSCCH signaling for multiple TTI transmissions.

BRIEF DESCRIPTION OF THE FIGURES

In the figures, which are not necessarily drawn to scale, like numerals may describe similar components in different views. Like numerals having different letter suffixes may represent different instances of similar components. The figures illustrate generally, by way of example, but not by way of limitation, various aspects discussed in the present document.

FIG. 1A illustrates an architecture of a network, in accordance with some aspects.

FIG. 1B and FIG. 1C illustrate a non-roaming 5G system architecture in accordance with some aspects.

FIG. 2 illustrates example signaling of sidelink resources, in accordance with some embodiments.

FIG. 3 illustrates an example of index calculation, in accordance with some embodiments.

FIG. 4 illustrates allocated sub-channels corresponding to a signaled index, in accordance with some embodiments.

FIG. 5 illustrates a block diagram of a communication device such as an evolved Node-B (eNB), a new generation Node-B (gNB), an access point (AP), a wireless station (STA), a mobile station (MS), or user equipment (UE), in accordance with some aspects.

DETAILED DESCRIPTION

The following description and the drawings sufficiently illustrate aspects to enable those skilled in the art to practice them. Other aspects may incorporate structural, logical, electrical, process, and other changes. Portions and features of some aspects may be included in or substituted for, those of other aspects. Aspects outlined in the claims encompass all available equivalents of those claims.

FIG. 1A illustrates an architecture of a network in accordance with some aspects. The network 140A is shown to include user equipment (UE) 101 and UE 102. The UEs 101 and 102 are illustrated as smartphones (e.g., handheld touchscreen mobile computing devices connectable to one or more cellular networks) but may also include any mobile or non-mobile computing device, such as Personal Data Assistants (PDAs), pagers, laptop computers, desktop computers, wireless handsets, drones, or any other computing device including a wired and/or wireless communications interface. The UEs 101 and 102 can be collectively referred to herein as UE 101, and UE 101 can be used to perform one or more of the techniques disclosed herein.

Any of the radio links described herein (e.g., as used in the network 140A or any other illustrated network) may operate according to any exemplary radio communication technology and/or standard.

LTE and LTE-Advanced are standards for wireless communications of high-speed data for UE such as mobile telephones. In LTE-Advanced and various wireless systems, carrier aggregation is a technology according to which multiple carrier signals operating on different frequencies may be used to carry communications for a single UE, thus increasing the bandwidth available to a single device. In some aspects, carrier aggregation may be used where one or more component carriers operate on unlicensed frequencies.

Aspects described herein can be used in the context of any spectrum management scheme including, for example, dedicated licensed spectrum, unlicensed spectrum, (licensed) shared spectrum (such as Licensed Shared Access (LSA) in 2.3-2.4 GHz, 3.4-3.6 GHz, 3.6-3.8 GHz, and further frequencies and Spectrum Access System (SAS) in 3.55-3.7 GHz and further frequencies).

Aspects described herein can also be applied to different Single Carrier or OFDM flavors (CP-OFDM, SC-FDMA, SC-OFDM, filter bank-based multicarrier (FBMC), OFDMA, etc.) and in particular 3GPP NR (New Radio) by allocating the OFDM carrier data bit vectors to the corresponding symbol resources.

In some aspects, any of the UEs 101 and 102 can comprise an Internet-of-Things (IoT) UE or a Cellular IoT (CIoT) UE, which can comprise a network access layer designed for low-power IoT applications utilizing short-lived UE connections. In some aspects, any of the UEs 101 and 102 can include a narrowband (NB) IoT UE (e.g., such as an enhanced NB-IoT (eNB-IoT) UE and Further Enhanced (FeNB-IoT) UE). An IoT UE can utilize technologies such as machine-to-machine (M2M) or machine-type communications (MTC) for exchanging data with an MTC server or device via a public land mobile network (PLMN), Proximity-Based Service (ProSe) or device-to-device (D2D) communication, sensor networks, or IoT networks. The M2M or MTC exchange of data may be a machine-initiated exchange of data. An IoT network includes interconnecting IoT UEs, which may include uniquely identifiable embedded computing devices (within the Internet infrastructure), with short-lived connections. The IoT UEs may execute background applications (e.g., keep-alive messages, status updates, etc.) to facilitate the connections of the IoT network.

In some aspects, any of the UEs 101 and 102 can include enhanced MTC (eMTC) UEs or further enhanced MTC (FeMTC) UEs.

The UEs 101 and 102 may be configured to connect, e.g., communicatively couple, with a radio access network (RAN) 110. The RAN 110 may be, for example, an Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN), a NextGen RAN (NG RAN), or some other type of RAN. The UEs 101 and 102 utilize connections 103 and 104, respectively, each of which comprises a physical communications interface or layer (discussed in further detail below); in this example, the connections 103 and 104 are illustrated as an air interface to enable communicative coupling and can be consistent with cellular communications protocols, such as a Global System for Mobile Communications (GSM) protocol, a code-division multiple access (CDMA) network protocol, a Push-to-Talk (PTT) protocol, a PTT over Cellular (POC) protocol, a Universal Mobile Telecommunications System (UMTS) protocol, a 3GPP Long Term Evolution (LTE) protocol, a fifth-generation (5G) protocol, a New Radio (NR) protocol, and the like.

In an aspect, the UEs 101 and 102 may further directly exchange communication data via a ProSe interface 105. The ProSe interface 105 may alternatively be referred to as a sidelink interface comprising one or more logical channels, including but not limited to a Physical Sidelink Control Channel (PSCCH), a Physical Sidelink Shared Channel (PSSCH), a Physical Sidelink Discovery Channel (PSDCH), and a Physical Sidelink Broadcast Channel (PSBCH).

The UE 102 is shown to be configured to access an access point (AP) 106 via connection 107. The connection 107 can comprise a local wireless connection, such as, for example, a connection consistent with any IEEE 802.11 protocol, according to which the AP 106 can comprise a wireless fidelity (WiFi®) router. In this example, the AP 106 is shown to be connected to the Internet without connecting to the core network of the wireless system (described in further detail below).

The RAN 110 can include one or more access nodes that enable the connections 103 and 104. These access nodes (ANs) can be referred to as base stations (BSs), NodeBs, evolved NodeBs (eNBs), Next Generation NodeBs (gNBs), RAN nodes, and the like, and can comprise ground stations (e.g., terrestrial access points) or satellite stations providing coverage within a geographic area (e.g., a cell). In some aspects, the communication nodes 111 and 112 can be transmission/reception points (TRPs). In instances when the communication nodes 111 and 112 are NodeBs (e.g., eNBs or gNBs), one or more TRPs can function within the communication cell of the NodeBs. The RAN 110 may include one or more RAN nodes for providing macrocells, e.g., macro RAN node 111, and one or more RAN nodes for providing femtocells or picocells (e.g., cells having smaller coverage areas, smaller user capacity, or higher bandwidth compared to macrocells), e.g., low power (LP) RAN node 112.

Any of the RAN nodes 111 and 112 can terminate the air interface protocol and can be the first point of contact for the UEs 101 and 102. In some aspects, any of the RAN nodes 111 and 112 can fulfill various logical functions for the RAN 110 including, but not limited to, radio network controller (RNC) functions such as radio bearer management, uplink and downlink dynamic radio resource management and data packet scheduling, and mobility management. In an example, any of the nodes 111 and/or 112 can be a new generation Node-B (gNB), an evolved node-B (eNB), or another type of RAN node.

The RAN 110 is shown to be communicatively coupled to a core network (CN) 120 via an S1 interface 113. In aspects, the CN 120 may be an evolved packet core (EPC) network, a NextGen Packet Core (NPC) network, or some other type of CN (e.g., as illustrated in reference to FIGS. 1B-1C). In this aspect, the S1 interface 113 is split into two parts: the S1-U interface 114, which carries traffic data between the RAN nodes 111 and 112 and the serving gateway (S-GW) 122, and the S1-mobility management entity (MME) interface 115, which is a signaling interface between the RAN nodes 111 and 112 and MMEs 121.

In this aspect, the CN 120 comprises the MMEs 121, the S-GW 122, the Packet Data Network (PDN) Gateway (P-GW) 123, and a home subscriber server (HSS) 124. The MMEs 121 may be similar in function to the control plane of legacy Serving General Packet Radio Service (GPRS) Support Nodes (SGSN). The MMEs 121 may manage mobility aspects in access such as gateway selection and tracking area list management. The HSS 124 may comprise a database for network users, including subscription-related information to support the network entities' handling of communication sessions. The CN 120 may comprise one or several HSSs 124, depending on the number of mobile subscribers, on the capacity of the equipment, on the organization of the network, etc. For example, the HSS 124 can provide support for routing/roaming, authentication, authorization, naming/addressing resolution, location dependencies, etc.

The S-GW 122 may terminate the S1 interface 113 towards the RAN 110, and routes data packets between the RAN 110 and the CN 120. In addition, the S-GW 122 may be a local mobility anchor point for inter-RAN node handovers and also may provide an anchor for inter-3GPP mobility. Other responsibilities of the S-GW 122 may include a lawful intercept, charging, and some policy enforcement.

The P-GW 123 may terminate an SGi interface toward a PDN. The P-GW 123 may route data packets between the EPC network 120 and external networks such as a network including the application server 184 (alternatively referred to as application function (AF)) via an Internet Protocol (IP) interface 125. The P-GW 123 can also communicate data to other external networks 131A, which can include the Internet, IP multimedia subsystem (IPS) network, and other networks. Generally, the application server 184 may be an element offering applications that use IP bearer resources with the core network (e.g., UMTS Packet Services (PS) domain, LTE PS data services, etc.). In this aspect, the P-GW 123 is shown to be communicatively coupled to an application server 184 via an IP interface 125. The application server 184 can also be configured to support one or more communication services (e.g., Voice-over-Internet Protocol (VoIP) sessions, PTT sessions, group communication sessions, social networking services, etc.) for the UEs 101 and 102 via the CN 120.

The P-GW 123 may further be a node for policy enforcement and charging data collection. Policy and Charging Rules Function (PCRF) 126 is the policy and charging control element of the CN 120. In a non-roaming scenario, in some aspects, there may be a single PCRF in the Home Public Land Mobile Network (HPLMN) associated with a UE's Internet Protocol Connectivity Access Network (IP-CAN) session. In a roaming scenario with a local breakout of traffic, there may be two PCRFs associated with a UE's IP-CAN session: a Home PCRF (H-PCRF) within an HPLMN and a Visited PCRF (V-PCRF) within a Visited Public Land Mobile Network (VPLMN). The PCRF 126 may be communicatively coupled to the application server 184 via the P-GW 123.

In some aspects, the communication network 140A can be an IoT network or a 5G network, including 5G new radio network using communications in the licensed (5G NR) and the unlicensed (5G NR-U) spectrum. One of the current enablers of IoT is the narrowband-IoT (NB-IoT).

An NG system architecture can include the RAN 110 and a 5G network core (5GC) 120. The NG-RAN 110 can include a plurality of nodes, such as gNBs and NG-eNBs. The core network 120 (e.g., a 5G core network or 5GC) can include an access and mobility function (AMF) and/or a user plane function (UPF). The AMF and the UPF can be communicatively coupled to the gNBs and the NG-eNBs via NG interfaces. More specifically, in some aspects, the gNBs and the NG-eNBs can be connected to the AMF by NG-C interfaces, and to the UPF by NG-U interfaces. The gNBs and the NG-eNBs can be coupled to each other via Xn interfaces.

In some aspects, the NG system architecture can use reference points between various nodes as provided by 3GPP Technical Specification (TS) 23.501 (e.g., V15.4.0, 2018-12). In some aspects, each of the gNBs and the NG-eNBs can be implemented as a base station, a mobile edge server, a small cell, a home eNB, and so forth. In some aspects, a gNB can be a master node (MN) and NG-eNB can be a secondary node (SN) in a 5G architecture.

FIG. 1B illustrates a non-roaming 5G system architecture in accordance with some aspects. Referring to FIG. 1B, there is illustrated a 5G system architecture 140B in a reference point representation. More specifically, UE 102 can be in communication with RAN 110 as well as one or more other 5G core (5GC) network entities. The 5G system architecture 140B includes a plurality of network functions (NFs), such as access and mobility management function (AMF) 132, session management function (SMF) 136, policy control function (PCF) 148, application function (AF) 150, user plane function (UPF) 134, network slice selection function (NSSF) 142, authentication server function (AUSF) 144, and unified data management (UDM)/home subscriber server (HSS) 146. The UPF 134 can provide a connection to a data network (DN) 152, which can include, for example, operator services, Internet access, or third-party services. The AMF 132 can be used to manage access control and mobility and can also include network slice selection functionality. The SMF 136 can be configured to set up and manage various sessions according to network policy. The UPF 134 can be deployed in one or more configurations according to the desired service type. The PCF 148 can be configured to provide a policy framework using network slicing, mobility management, and roaming (similar to PCRF in a 4G communication system). The UDM can be configured to store subscriber profiles and data (similar to an HSS in a 4G communication system).

In some aspects, the 5G system architecture 140B includes an IP multimedia subsystem (IMS) 168B as well as a plurality of IP multimedia core network subsystem entities, such as call session control functions (CSCFs). More specifically, the IMS 168B includes a CSCF, which can act as a proxy CSCF (P-CSCF) 162BE, a serving CSCF (S-CSCF) 164B, an emergency CSCF (E-CSCF) (not illustrated in FIG. 1B), or interrogating CSCF (I-CSCF) 166B. The P-CSCF 162B can be configured to be the first contact point for the UE 102 within the IM subsystem (IMS) 168B. The S-CSCF 164B can be configured to handle the session states in the network, and the E-CSCF can be configured to handle certain aspects of emergency sessions such as routing an emergency request to the correct emergency center or PSAP. The I-CSCF 166B can be configured to function as the contact point within an operator's network for all IMS connections destined to a subscriber of that network operator, or a roaming subscriber currently located within that network operator's service area. In some aspects, the I-CSCF 166B can be connected to another IP multimedia network 170E, e.g. an IMS operated by a different network operator.

In some aspects, the UDM/HSS 146 can be coupled to an application server 160E, which can include a telephony application server (TAS) or another application server (AS). The AS 160B can be coupled to the IMS 168B via the S-CSCF 164B or the I-CSCF 166B.

A reference point representation shows that interaction can exist between corresponding NF services. For example, FIG. 1B illustrates the following reference points: N1 (between the UE 102 and the AMF 132), N2 (between the RAN 110 and the AMF 132), N3 (between the RAN 110 and the UPF 134), N4 (between the SMF 136 and the UPF 134), N5 (between the PCF 148 and the AF 150, not shown), N6 (between the UPF 134 and the DN 152), N7 (between the SMF 136 and the PCF 148, not shown), N8 (between the UDM 146 and the AMF 132, not shown), N9 (between two UPFs 134, not shown), N10 (between the UDM 146 and the SMF 136, not shown), N11 (between the AMF 132 and the SMF 136, not shown), N12 (between the AUSF 144 and the AMF 132, not shown), N13 (between the AUSF 144 and the UDM 146, not shown), N14 (between two AMFs 132, not shown), N15 (between the PCF 148 and the AMF 132 in case of a non-roaming scenario, or between the PCF 148 and a visited network and AMF 132 in case of a roaming scenario, not shown), N16 (between two SMFs, not shown), and N22 (between AMF 132 and NSSF 142, not shown). Other reference point representations not shown in FIG. 1E can also be used.

FIG. 1C illustrates a 5G system architecture 140C and a service-based representation. In addition to the network entities illustrated in FIG. 1B, system architecture 140C can also include a network exposure function (NEF) 154 and a network repository function (NRF) 156. In some aspects, 5G system architectures can be service-based and interaction between network functions can be represented by corresponding point-to-point reference points Ni or as service-based interfaces.

In some aspects, as illustrated in FIG. 1C, service-based representations can be used to represent network functions within the control plane that enable other authorized network functions to access their services. In this regard, 5G system architecture 140C can include the following service-based interfaces: Namf 158H (a service-based interface exhibited by the AMF 132), Nsmf 1581 (a service-based interface exhibited by the SMF 136), Nnef 158B (a service-based interface exhibited by the NEF 154), Npcf 158D (a service-based interface exhibited by the PCF 148), a Nudm 158E (a service-based interface exhibited by the UDM 146), Naf 158F (a service-based interface exhibited by the AF 150), Nnrf 158C (a service-based interface exhibited by the NRF 156), Nnssf 158A (a service-based interface exhibited by the NSSF 142), Nausf 158G (a service-based interface exhibited by the AUSF 144). Other service-based interfaces (e.g., Nudr, N5g-eir, and Nudsf) not shown in FIG. 1C can also be used.

In example embodiments, any of the UEs or base stations discussed in connection with FIG. 1A-FIG. 1C can be configured to operate using the techniques discussed in connection with FIG. 2-FIG. 5.

In the case of resource sensing for intended resource selection, it is of benefit that one sidelink control information (SCI) is signaling physical sidelink shared channel (PSSCH) resources allocated for the transmission of the same transport block (TB) in multiple slots (or transmission time intervals, or TTIs). As the SCI in the PSCCH is communicated with the most robust physical layer format, every additional bit in the SCI influences the overall coverage. Thus, techniques discussed herein may be used as a solution for the required signaling of the PSSCH resources in multiple TTIs. In some aspects, a minimal number of bits in the SCI are signaled, which enables the control channel to have maximum coverage with minimized resources.

FIG. 2 illustrates example signaling of sidelink resources, in accordance with some embodiments. More specifically, the example in FIG. 2 shows the different possible PSCCH and PSSCH signaling. In a), all transmissions are within the same scheduling window. This means that the resource signaling (e.g., PSCCH) only needs to signal the resources within this window. In contrast in b), the first PSCCH transmission signals two following transmissions. But in the second of those two transmissions, it is decided that possibly additional resources are needed. Therefore, in the second transmission, additional PSCCH resources are signaled. In some aspects, the number of signaled transmissions is limited to three and there are no signaling resources left to point to the resources of the preceding transmission, thus only the future resources are signaled.

In some aspects, to enhance the reliability of transmissions for NR V2X, blind retransmissions may be enabled similarly as in LTE V2X. These multiple resources may be signaled by the control channel. In addition, in some aspects, it may be beneficial to signal not only the next but all transmissions belonging to the same transport block (TB). In addition, this has benefits for the resource sensing procedure as this signaling of future resources can be interpreted as a resource reservation. As every additional bit in the SCI has a significant impact on the performance, efficiency for this signaling may be of interest. The following paragraphs describe in detail the aspects and techniques of the PSCCH signaling.

Signaling of Resources in the Current Transmission Time Interval (TTI):

In some aspects, for the demodulation of the resource in the current TTI, the position and number of the allocated sub-channels may be signaled. Additional assumptions can reduce this signaling. For example, it is possible to assume that the control channel is always only present in the sub-channel containing the PRBs with the smallest PRB index of the whole transmission. This means only the size of the allocation in terms of sub-channels needs to be signaled as the starting position can be directly inferred from the position of the PSCCH.

In some aspects, an option of current TTI signaling may employ a resource indication value (RIV) approach which may be used for jointly encoding sub-channel offset and number of sub-channels within a given sub-channel set. If

$N_s-1\le \mathrm{floor}\left(\frac{S}{2}\right),\mathrm{RIV}=S·\left(N_S-1\right)+i,\mathrm{else}\mathrm{RIV}=S·\left(S-N_S+1\right)+\left(S-1-i\right),$

where N_S is the number of allocated sub-channels, S is the number of sub-channels in an SL BWP, and i is the lowest index of the allocated sub-channel.

Signaling of Frequency Resource Assignments for Transmissions in Other TTIs:

In some aspects, to be able to identify future or past resources of the same TB from the same transmitter, it may be necessary to know the frequency resource assignment(s). The signaling overhead can be reduced if additional side information is used. For example, the transmission can be restricted to use the same amount for sub-channel for each transmission. This means that only the starting sub-channel may need to be signaled for each TTI.

Signaling of the Time Location of Transmissions in Other TTIs:

In some aspects, for this signaling, all transmission may be assumed to be within a signaling window. In some aspects, the window size may be (pre)-configured. Separately signaling the position of each location is a large overhead. In some aspects, a Look-Up Table (LUT) may be generated and used to signal all possibilities that are not redundant. The LUT may also take into account that each signaling does not necessarily signal the maximum number of possible allocations. The LUT can be constructed in containing all possibilities of selection 0 to N values out of M, where M is the (pre)-configured signaling window size and N is the maximum number of transmissions within this window. Another way to construct the LUT would be to simply signal the distances between conductive transmissions. This means instead of the location inside the window only the distance between adjacent transmissions is signaled. For signaling the distance it is also important that the number of transmissions is also signaled.

In some aspects, the signaling of N TTIs in a window of M slots may be defined as follows using a combinatorial index approach similar to the one used for EPDCCH or SPDCCH PRB-pair resource set configuration. That is, a combinatorial index r corresponding to N TTI indexes from window M, with {k_i}_i=0^M, (1≤k_i≤M, k_i<k_i+1) and given by equation

$\sum _{i=0}^{N-1}〈\begin{array}{c}M-k_i\\ N-k_i\end{array}〉,$

where

$〈\begin{array}{c}y\\ y\end{array}〉=\{\begin{array}{cc}\left(\begin{array}{c}x\\ y\end{array}\right)& x\ge y\\ 0& x<y\end{array}$

is the extended binomial coefficient, resulting in unique label r

$\in \left\{0,\dots ,\left(\begin{array}{c}M\\ N\end{array}\right)-1\right\}.$

This rule can be extended to signal 0, 1, . . . , N resources out M by concatenation of all possible combinatorial indexes, like r

$\in \left\{0,\dots ,\left(\begin{array}{c}M\\ N\end{array}\right)-1,\left(\begin{array}{c}M\\ N\end{array}\right),\dots ,\left(\begin{array}{c}M\\ N\end{array}\right)+\left(\begin{array}{c}M\\ N-1\end{array}\right)-1,\left(\begin{array}{c}M\\ N\end{array}\right)+\left(\begin{array}{c}M\\ N-1\end{array}\right),\dots ,\left(\begin{array}{c}M\\ N\end{array}\right)+\left(\begin{array}{c}M\\ N-1\end{array}\right)+\left(\begin{array}{c}M\\ N-2\end{array}\right)-1,\dots \right\}.$

SCI/PSCCH may indicate resources for N TTIs, where N−1 TTIs are from the past or future. Therefore, one TTI is already identified in the window M, thus the combinatorial index should signal N−1 TTIs in a window M−1.

In a special case of N=2 and 3 and window size M, when both numbers 2 and 3 need to be supported by the same indexing, the combinatorial index approach can be used by letting N′=3 and M′=M+1. In this case, when N TTIs lay into window M, all N TTIs are assumed signaled. When one TTI from N lays to the last TTI of window M′ (M+1), this TTI is not assumed available/valid, while other N−1 TTIs laying into window M are interpreted as signaled.

Signaling of Transmission Index in the Current Window:

As from the signaling of the time resource assignment(s), it may not be evident which TTI the current SCI transmission is within. In some aspects, a transmission index inside the current TTI (or any additional TTIs) may be added to the transmission within the current scheduling window.

For example, for N TTI transmissions, signaling of size ceil(log 2(N)) may be used to indicate the transmission index.

Signaling to Identify that Transmissions Belong to the Same TB:

As additional resources can belong to the same TB but are not within the same transmission window it needs to be identified that they belong to the same transmission. Thus, even for broadcast a HARQ ID plus new data indication (NDI) needs to be used.

Additional Side Information that can be Used

In some aspects, if the same resources in adjacent slots are signaled this can be interpreted as slot aggregation is used. Thus, this signaling framework allows to signal slot aggregation up to the maximum number of slots (pre)-configured to be within a sensing window. These aggregated slots can either contain control information themselves or completely omit the control information.

Joint Time-Frequency Signaling for Resource Reservation:

In most current resource signaling schemes, the time and frequency resources are signaled independently. It is possible to jointly signal the time and frequency resource using a combinatorial indexing method. Assuming that all N_max transmissions have the same amount of sub-channels allocated and there are in total N_CH sub-channels available in the resource pool. The number of combinations and thus the combinatorial index can be calculated with the following formula:

$\sum _{n=0}^{N_{\max }-1}\left(\begin{array}{c}W\\ n\end{array}\right)\sum _{m=1}^{N_{\mathrm{CH}}}{\left(N_{\mathrm{CH}}+1-m\right)}^n.$

In some aspects, the number of allocated sub-channels in each allocation is different. This would lead to the following formula for the number of combinations and the combinatorial index:

$\sum _{n=0}^{N_{\max }-1}\left(\begin{array}{c}W\\ n\end{array}\right){\left(\sum _{m=1}^{N_{\mathrm{CH}}}\left(N_{\mathrm{CH}}+1-m\right)\right)}^nN_{CH}.$

In some aspects, the case that the initial transmission has only a single sub-channel allocated may be signaled. This could just be a separate bit, or it could be combined inside the TTI index if the number of TTI indices is not fully representing N bits. An example would be that a maximum of 3 TTIs can be signaled. This means at least 2 bits may be used for the TTI index. However, as there are only 3 TTIs, the 4th value has no meaning and could be used to represent and reduced size initial transmission.

The details of the joint time-frequency signaling are provided hereinbelow, which includes an example of how to implement it. It is however possible to do the index calculation in a different order or change the meaning of some part of the used values.

Encoding Procedure

Input: Number of available sub-channels in a slot: N_CH; Window length: W; Number of resources signaled beyond the first: n; Number of allocated sub-channels: m; List of selected time indices after the current slot (indexing slots after the current one starting with 1): l₀, . . . , l_n−1 sorted in acceding order, and List of sub-channel start indices in ever slot k₀, . . . , k_n−1.

Step 1: Calculate the offset of the selected number of allocated time slots based on the parameters N_CH, W, n as:

$a=\{\begin{array}{cc}\sum _{i=0}^{n-1}\left(\begin{array}{c}W\\ i\end{array}\right)\sum _{j=1}^{N_{\mathrm{CH}}}{\left(N_{CH}+1-j\right)}^i& f\mathrm{or}n>0\\ 0& f\mathrm{or}n=0\end{array}.$

Step 2: Calculate the offset of the selected number of allocated sub-channels based on the parameters N_CH, W, n, m:

$b=\{\begin{array}{cc}\left(\begin{array}{c}W\\ n\end{array}\right)\sum _{j=1}^{m-1}{\left(N_{CH}+1-j\right)}^n& f\mathrm{or}m>1,n>0\\ 0& f\mathrm{or}m=1\mathrm{or}n=0\end{array}.$

Step 3: Calculate the index related to the allocated time slots: c=

$\{\begin{array}{cc}\left(\sum _{i=0}^{n-1}〈\begin{array}{c}W-l_i\\ n-i\end{array}〉\right)& f\mathrm{or}n>0\\ 0& f\mathrm{or}n=0\end{array},$

where the function is defined as:

$〈\begin{array}{c}x\\ y\end{array}〉=\{\begin{array}{cc}\left(\begin{array}{c}x\\ y\end{array}\right)& \forall x\ge y\\ 0& \forall x<y\end{array}.$

Step 4: Calculate the index related to the start sub-channel index:

$d=\{\begin{array}{cc}\sum _{j=0}^{n-1}{\left(N_{CH}+1-m\right)}^jk_j& n>0\\ m-1& n=0\end{array}.$

Step 5: Combining the calculated values to form the final index: index=a+b+(N_CH+1 m)ⁿc+d.

It is in addition possible to change the order of the calculation of the time and frequency allocation indexing. To separate the two parts it is necessary to scale the index of the frequency sub-channel indices by the maximum number of possibilities of allocating time slots.

Encoding Procedure Example

FIG. 3 illustrates a diagram 300 with an example for index calculation, in accordance with some embodiments.

In some aspects, the corresponding index to the allocation given in FIG. 3 is calculated. As part of the pool definition the parameters N_CH=2 and W=15 are defined. From FIG. 3 it may be noted that l₀=6, l₁=10 and k₀=0, k₁=1. In addition, there is one sub-channel allocated in each slot (m=1) and there are in total 3 time slots (n=2). This leads to the following values for a=47, b=0, c=41, d=2, and thus resulting index index=213.

Decoding Procedure

This decoding procedure does not include the case for n=0, as for one allocated slot the calculation is trivial and the resulting index is equal to the number of allocated sub-channels −1.

Input: Number of available sub-channels in a slot: N_CH; Window length: W; and Transmitted combinatorial index: index.

Step 1: Determine the value of n and update the residual index. Calculate the index associated with a different number of allocated slots n as:

$a_n=\left(\sum _{i=0}^{n-1}\left(\begin{array}{c}W\\ i\end{array}\right)\sum _{j=1}^{N_{\mathrm{CH}}}{\left(N_{CH}+1-j\right)}^i\right)\forall n\in \left\{1,\text{...},N_{\max }-1\right\}.$

Determine n via checking for which value the following formula is valid: a_n≤index <a_n+1, where a₀=0, a_Nmax=∞. Calculate the index inside the determined value of n, index←index−a_n.

Step 2: Determine the value of m and update the residual index. Calculate the index associated with a different number of allocated sub-channels m as:

$b_m=\left(\begin{array}{c}W\\ n\end{array}\right)\sum _{j=1}^{m-1}{\left(N_{CH}+1-j\right)}^n\forall m\in \left\{2,\dots ,N_{CH}\right\}.$

Determine m via checking for which value the following formula is valid: b_m≤index <b_m+1, where b₁=0, b_NCH+1=∞. Calculate the index inside the determined value of m, index←index−b_m.

Step 3: Determine the indicated index for the allocated slots as

$c=\lfloor \frac{\mathrm{index}}{{\left(N_{CH}+1-m\right)}^n}\rfloor .$

From c, the slot indices l_i∇i∈{0, . . . , n−1} are determined from a lookup table containing the mapping of the index to the allocated slots.

Step 4: Determine the indicated index for the start allocated sub-channels as

$d=\mathrm{index}-\lfloor \frac{\mathrm{index}}{{\left(N_{CH}+1-m\right)}^n}\rfloor {\left(N_{CH}+1-m\right)}^n.$

Determine k_j as:

$k_j=\mathrm{modulo}\left(\lfloor \frac{d}{{\left(N_{CH}+1-m\right)}^j}\rfloor ,\left(N_{CH}+1-m\right)\right)\forall j\in \left\{0,\dots ,n-1\right\}.$

As also mentioned in the descriptions of the encoding, if the order of processing the time slot indices and the frequency sub-channel indices are exchanged, different scaling may be applied.

Decoding Procedure Example

FIG. 4 illustrates a diagram 400 of allocated sub-channels corresponding to a signaled index, in accordance with some embodiments. Taking the same parameters of the resource pool configuration: N_CH=2 and W=15 are defined. It is assumed that the index=308 is received. The values we calculate for an are {0, 2, 47, ∞}. Thus, n=2 is determined and the residual index is calculated as index←index−a_n as 261=308-47. The calculation of b_m, the following values {0, 420, ∞} are obtained. This means m=1 is used for the transmission. As the b_m=0 there is no update of the residual index. From this result, the value of c=65 is calculated. From the LUT of the mapping to time indices, l₀=5 and l₁=6 is determined. For calculating the sub-channel start indices, d=1 is initially determined. This means the start indices are equal to k₀=1 and k₁=0. With all the parameters determined, it is ascertained that the transmitted index represents the allocation in FIG. 4.

In some aspects, an SCI signaling scheme for the reservation of PSSCH resources in multiple TTIs is disclosed. In some aspects, the allocated sub-channels in the current TTI is signaled via resource indication value. In some aspects, the allocated sub-channels are signaled via a from the location of the PSCCH derived start index and an explicitly signaled size. In some aspects, the frequency allocation in other TTIs is signaled via a resource indication value. In some aspects, the frequency allocation only with the starting index, assuming the number of sub-channels allocated is the same for each transmission belonging to the same TB. In some aspects, the time location of the transmissions in other TTI is signaled via a combinatorial index based on the location relative to the start of the window. In some aspects, the time location of the transmissions in other TTI is signaled via a combinatorial index based on the distance between adjacent transmissions. In some aspects, the index of the current transmission in the window is explicitly signaled. In some aspects, slot aggregation or concatenation is implicitly signaled if the same frequency resources are allocated in consecutive TTI.

In some aspects, an SCI signaling scheme for reservation of PSSCH resource in multiple TTI is disclosed where the time-frequency resources are jointly signaled. In some aspects, the amount of frequency resources in each TTI is the same. In some aspects, the amount of frequency resources in each TTI is different. In some aspects, an initial reduced size transmission is separately signaled. In some aspects, an initial reduced size transmission is signaled as part of the TTI index. In some aspects, the index is encoded using any combination and order of the following parameters: number of allocated slots, number of allocated sub-channels, slot index in the window, and start sub-channel index in each slot. In some aspects, the index calculation is having the special case of single-slot allocation. In some aspects, the calculation of the allocated sub-channels is converting a single index into any combination and order of the following parameters: number of allocated slots, number of allocated sub-channels, slot index in the window and start sub-channel index in each slot.

FIG. 5 illustrates a block diagram of a communication device such as an evolved Node-B (eNB), a next generation Node-B (gNB), an access point (AP), a wireless station (STA), a mobile station (MS), or user equipment (UE), in accordance with some aspects and to perform one or more of the techniques disclosed herein. In alternative aspects, the communication device 500 may operate as a standalone device or may be connected (e.g., networked) to other communication devices.

Circuitry (e.g., processing circuitry) is a collection of circuits implemented in tangible entities of the device 500 that include hardware (e.g., simple circuits, gates, logic, etc.). Circuitry membership may be flexible over time. Circuitries include members that may, alone or in combination, perform specified operations when operating. In an example, the hardware of the circuitry may be immutably designed to carry out a specific operation (e.g., hardwired). In an example, the hardware of the circuitry may include variably connected physical components (e.g., execution units, transistors, simple circuits, etc.) including a machine-readable medium physically modified (e.g., magnetically, electrically, moveable placement of invariant massed particles, etc.) to encode instructions of the specific operation.

In connecting the physical components, the underlying electrical properties of a hardware constituent are changed, for example, from an insulator to a conductor or vice versa. The instructions enable embedded hardware (e.g., the execution units or a loading mechanism) to create members of the circuitry in hardware via the variable connections to carry out portions of the specific operation when in operation. Accordingly, in an example, the machine-readable medium elements are part of the circuitry or are communicatively coupled to the other components of the circuitry when the device is operating. In an example, any of the physical components may be used in more than one member of more than one circuitry. For example, under operation, execution units may be used in a first circuit of a first circuitry at one point in time and reused by a second circuit in the first circuitry, or by a third circuit in a second circuitry at a different time. Additional examples of these components with respect to the device 500 follow.

In some aspects, the device 500 may operate as a standalone device or may be connected (e.g., networked) to other devices. In a networked deployment, the communication device 500 may operate in the capacity of a server communication device, a client communication device, or both in server-client network environments. In an example, the communication device 500 may act as a peer communication device in peer-to-peer (P2P) (or other distributed) network environment. The communication device 500 may be a UE, eNB, PC, a tablet PC, an STB, a PDA, a mobile telephone, a smartphone, a web appliance, a network router, switch or bridge, or any communication device capable of executing instructions (sequential or otherwise) that specify actions to be taken by that communication device. Further, while only a single communication device is illustrated, the term “communication device” shall also be taken to include any collection of communication devices that individually or jointly execute a set (or multiple sets) of instructions to perform any one or more of the methodologies discussed herein, such as cloud computing, software as a service (SaaS), and other computer cluster configurations.

Examples, as described herein, may include, or may operate on, logic or a number of components, modules, or mechanisms. Modules are tangible entities (e.g., hardware) capable of performing specified operations and may be configured or arranged in a certain manner. In an example, circuits may be arranged (e.g., internally or with respect to external entities such as other circuits) in a specified manner as a module. In an example, the whole or part of one or more computer systems (e.g., a standalone, client or server computer system) or one or more hardware processors may be configured by firmware or software (e.g., instructions, an application portion, or an application) as a module that operates to perform specified operations. In an example, the software may reside on a communication device-readable medium. In an example, the software, when executed by the underlying hardware of the module, causes the hardware to perform the specified operations.

Accordingly, the term “module” is understood to encompass a tangible entity, be that an entity that is physically constructed, specifically configured (e.g., hardwired), or temporarily (e.g., transitorily) configured (e.g., programmed) to operate in a specified manner or to perform part or all of any operation described herein. Considering examples in which modules are temporarily configured, each of the modules need not be instantiated at any one moment in time. For example, where the modules comprise a general-purpose hardware processor configured using the software, the general-purpose hardware processor may be configured as respective different modules at different times. The software may accordingly configure a hardware processor, for example, to constitute a particular module at one instance of time and to constitute a different module at a different instance of time.

The communication device (e.g., UE) 500 may include a hardware processor 502 (e.g., a central processing unit (CPU), a graphics processing unit (GPU), a hardware processor core, or any combination thereof), a main memory 504, a static memory 506, and mass storage 507 (e.g., hard drive, tape drive, flash storage, or other block or storage devices), some or all of which may communicate with each other via an interlink (e.g., bus) 508.

The communication device 500 may further include a display device 510, an alphanumeric input device 512 (e.g., a keyboard), and a user interface (UI) navigation device 514 (e.g., a mouse). In an example, the display device 510, input device 512, and UI navigation device 514 may be a touchscreen display. The communication device 500 may additionally include a signal generation device 518 (e.g., a speaker), a network interface device 520, and one or more sensors 521, such as a global positioning system (GPS) sensor, compass, accelerometer, or another sensor. The communication device 500 may include an output controller 528, such as a serial (e.g., universal serial bus (USB), parallel, or other wired or wireless (e.g., infrared (IR), near field communication (NFC), etc.) connection to communicate or control one or more peripheral devices (e.g., a printer, card reader, etc.).

The storage device 507 may include a communication device-readable medium 522, on which is stored one or more sets of data structures or instructions 524 (e.g., software) embodying or utilized by any one or more of the techniques or functions described herein. In some aspects, registers of the processor 502, the main memory 504, the static memory 506, and/or the mass storage 507 may be, or include (completely or at least partially), the device-readable medium 522, on which is stored the one or more sets of data structures or instructions 524, embodying or utilized by any one or more of the techniques or functions described herein. In an example, one or any combination of the hardware processor 502, the main memory 504, the static memory 506, or the mass storage 516 may constitute the device-readable medium 522.

As used herein, the term “device-readable medium” is interchangeable with “computer-readable medium” or “machine-readable medium”. While the communication device-readable medium 522 is illustrated as a single medium, the term “communication device-readable medium” may include a single medium or multiple media (e.g., a centralized or distributed database, and/or associated caches and servers) configured to store the one or more instructions 524. The term “communication device-readable medium” is inclusive of the terms “machine-readable medium” or “computer-readable medium”, and may include any medium that is capable of storing, encoding, or carrying instructions (e.g., instructions 524) for execution by the communication device 500 and that cause the communication device 500 to perform any one or more of the techniques of the present disclosure, or that is capable of storing, encoding or carrying data structures used by or associated with such instructions. Non-limiting communication device-readable medium examples may include solid-state memories and optical and magnetic media. Specific examples of communication device-readable media may include non-volatile memory, such as semiconductor memory devices (e.g., Electrically Programmable Read-Only Memory (EPROM), Electrically Erasable Programmable Read-Only Memory (EEPROM)) and flash memory devices; magnetic disks, such as internal hard disks and removable disks; magneto-optical disks; Random Access Memory (RAM); and CD-ROM and DVD-ROM disks. In some examples, communication device-readable media may include non-transitory communication device-readable media. In some examples, communication device-readable media may include communication device-readable media that is not a transitory propagating signal.

The instructions 524 may further be transmitted or received over a communications network 526 using a transmission medium via the network interface device 520 utilizing any one of a number of transfer protocols. In an example, the network interface device 520 may include one or more physical jacks (e.g., Ethernet, coaxial, or phone jacks) or one or more antennas to connect to the communications network 526. In an example, the network interface device 520 may include a plurality of antennas to wirelessly communicate using at least one of single-input-multiple-output (SIMO), MIMO, or multiple-input-single-output (MISO) techniques. In some examples, the network interface device 520 may wirelessly communicate using Multiple User MIMO techniques.

The term “transmission medium” shall be taken to include any intangible medium that is capable of storing, encoding or carrying instructions for execution by the communication device 500, and includes digital or analog communications signals or another intangible medium to facilitate communication of such software. In this regard, a transmission medium in the context of this disclosure is a device-readable medium.

Although an aspect has been described with reference to specific exemplary aspects, it will be evident that various modifications and changes may be made to these aspects without departing from the broader scope of the present disclosure. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense. This Detailed Description, therefore, is not to be taken in a limiting sense, and the scope of various aspects is defined only by the appended claims, along with the full range of equivalents to which such claims are entitled.

Claims

1. An apparatus to be used in a user equipment (UE), the apparatus comprising: processing circuitry, wherein to configure the UE for 5G-New Radio (NR) sidelink communications, the processing circuitry is to: decode sidelink control information (SCI) received from a second UE via a physical sidelink control channel (PSCCH), the SCI indicating sidelink resources for transmission of a transport block during multiple transmission time intervals;determine a frequency resource assignment and a time resource assignment for the multiple transmission time intervals based on the sidelink resources; anddecode a physical sidelink shared channel (PSSCH), the PSSCH including the transport block and received in one of the multiple transmission time intervals using the frequency resource assignment and the time resource assignment; anda memory coupled to the processing circuitry and configured to store the SCI.

2. The apparatus of claim 1, wherein the multiple transmission time intervals comprise two transmission time intervals or three transmission time intervals.

3. The apparatus of claim 1, wherein the frequency resource assignment comprises a plurality of sub-channels for each of the multiple transmission time intervals.

4. The apparatus of claim 3, wherein a number of sub-channels in each of the plurality of sub-channels is the same for each of the multiple transmission time intervals.

5. The apparatus of claim 1, wherein the frequency resource assignment comprises a starting sub-channel index for each of the multiple transmission time intervals.

6. The apparatus of claim 5, wherein the frequency resource assignment further comprises a number of sub-channels within each of the multiple transmission time intervals.

7. The apparatus of claim 1, wherein the frequency resource assignment for the one of the multiple transmission time intervals is signaled via a resource indicator value (RIV).

8. The apparatus of claim 7, wherein the RIV indicates a number of sub-channels within the one of the multiple transmission time intervals.

9. The apparatus of claim 7, wherein the RIV indicates a number of sub-channels within each of the multiple transmission time intervals.

10. The apparatus of claim 1, further comprising transceiver circuitry coupled to the processing circuitry; and, one or more antennas coupled to the transceiver circuitry.

11. A non-transitory computer-readable storage medium that stores instructions for execution by one or more processors of a user equipment (UE), the instructions to configure the UE for 5G-New Radio (NR) sidelink communications, and to cause the UE to: encode sidelink control information (SCI) for transmission to a second UE via a physical sidelink control channel (PSCCH), the SCI indicating sidelink resources for transmission of a transport block during multiple transmission time intervals, the sidelink resources including a frequency resource assignment and a time resource assignment for the multiple transmission time intervals; andencode a physical sidelink shared channel (PSSCH) for transmission in one of the multiple transmission time intervals using the frequency resource assignment and the time resource assignment, the PSSCH including the transport block.

12. The computer-readable storage medium of claim 11, wherein the multiple transmission time intervals comprise two transmission time intervals or three transmission time intervals.

13. The computer-readable storage medium of claim 11, wherein the frequency resource assignment comprises a plurality of sub-channels for each of the multiple transmission time intervals.

14. The computer-readable storage medium of claim 13, wherein a number of sub-channels in each of the plurality of sub-channels is the same for each of the multiple transmission time intervals.

15. A non-transitory computer-readable storage medium that stores instructions for execution by one or more processors of a user equipment (UE), the instructions to configure the UE for 5G-New Radio (NR) sidelink communications, and to cause the UE to: decode sidelink control information (SCI) received from a second UE via a physical sidelink control channel (PSCCH), the SCI indicating sidelink resources for transmission of a transport block during multiple transmission time intervals;determine a frequency resource assignment and a time resource assignment for the multiple transmission time intervals based on the sidelink resources; anddecode a physical sidelink shared channel (PSSCH), the PSSCH including the transport block, and received in one of the multiple transmission time intervals using the frequency resource assignment and the time resource assignment.

16. The computer-readable storage medium of claim 15, wherein the multiple transmission time intervals comprise two transmission time intervals or three transmission time intervals.

17. The computer-readable storage medium of claim 15, wherein the frequency resource assignment comprises a plurality of sub-channels for each of the multiple transmission time intervals.

18. The computer-readable storage medium of claim 17, wherein a number of sub-channels in each of the plurality of sub-channels is the same for each of the multiple transmission time intervals.

19. The computer-readable storage medium of claim 15, wherein the frequency resource assignment comprises a starting sub-channel index for each of the multiple transmission time intervals.

20. The computer-readable storage medium of claim 19, wherein the frequency resource assignment further comprises a number of sub-channels within each of the multiple transmission time intervals.