Patent Application
20240178961
Field
The present disclosure relates generally to communication systems, and more particularly, to techniques of providing diversity gain via device aggregation.
The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasts. Typical wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources. Examples of such multiple-access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single-carrier frequency division multiple access (SC-FDMA) systems, and time division synchronous code division multiple access (TD-SCDMA) systems.
These multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate on a municipal, national, regional, and even global level. An example telecommunication standard is 5G Nesw Radio (NR). 5G NR is part of a continuous mobile broadband evolution promulgated by Third Generation Partnership Project (3GPP) to meet new requirements associated with latency, reliability, security, scalability (e.g., with Internet of Things (IoT)), and other requirements. Some aspects of 5G NR may be based on the 4G Long Term Evolution (LTE) standard. There exists a need for further improvements in 5G NR technology. These improvements may also be applicable to other multi-access technologies and the telecommunication standards that employ these technologies.
The following presents a simplified summary of one or more aspects in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects, and is intended to neither identify key or critical elements of all aspects nor delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later.
In an aspect of the disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus may be a first wireless device. The first wireless device receives, from a base station, a configuration of first reference signals on a first time-frequency resource. The first wireless device measures the first reference signals received from the base station to obtain first measurements for a direct path between the base station and the first wireless device. The first wireless device obtains second measurements for an indirect path between the base station and the first wireless device via a second wireless device. The first wireless device selects a communication path from the direct path and the indirect path based at least in part on the first measurements and the second measurements.
In another aspect of the disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus may be a base station. The base station configures first reference signals on a first time-frequency resource for a second wireless device to measure channel conditions between the base station and the second wireless device. The base station configures second reference signals on a second time-frequency resource for a first wireless device to measure channel conditions between the base station and the second wireless device. The base station transmits the first reference signals and the second reference signals. The base station receives, from the second wireless device, first measurements of the first reference signals.
The base station receives, from the first wireless device, second measurements of the second reference signals. The base station selects a communication path, for communicating data between the base station and the first wireless device, from a direct path between the base station and the first wireless device and an indirect path between the base station and the first wireless device via the second wireless device based at least in part on the received first measurements and second measurements. The base station transmits control information to the first wireless device indicating the communication path for communicating data with the base station.
To the accomplishment of the foregoing and related ends, the one or more aspects comprise the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative features of the one or more aspects. These features are indicative, however, of but a few of the various ways in which the principles of various aspects may be employed, and this description is intended to include all such aspects and their equivalents.
a repeater.
The detailed description set forth below in connection with the appended drawings is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of various concepts. However, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details. In some instances, well known structures and components are shown in block diagram form in order to avoid obscuring such concepts.
Several aspects of telecommunication systems will now be presented with reference to various apparatus and methods. These apparatus and methods will be described in the following detailed description and illustrated in the accompanying drawings by various blocks, components, circuits, processes, algorithms, etc. (collectively referred to as “elements”). These elements may be implemented using electronic hardware, computer software, or any combination thereof. Whether such elements are implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system.
By way of example, an element, or any portion of an element, or any combination of elements may be implemented as a “processing system” that includes one or more processors. Examples of processors include microprocessors, microcontrollers, graphics processing units (GPUs), central processing units (CPUs), application processors, digital signal processors (DSPs), reduced instruction set computing (RISC) processors, systems on a chip (SoC), baseband processors, field programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functionality described throughout this disclosure. One or more processors in the processing system may execute software. Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software components, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise.
Accordingly, in one or more example embodiments, the functions described may be implemented in hardware, software, or any combination thereof. If implemented in software, the functions may be stored on or encoded as one or more instructions or code on a computer-readable medium. Computer-readable media includes computer storage media. Storage media may be any available media that can be accessed by a computer. By way of example, and not limitation, such computer- readable media can comprise a random-access memory (RAM), a read-only memory (ROM), an electrically erasable programmable ROM (EEPROM), optical disk storage, magnetic disk storage, other magnetic storage devices, combinations of the aforementioned types of computer-readable media, or any other medium that can be used to store computer executable code in the form of instructions or data structures that can be accessed by a computer.
The base stations 102 (collectively referred to as Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN)) interface with the core network 160 through backhaul links 132 (e.g., S1 interface). In addition to other functions, the base stations 102 may perform one or more of the following functions: transfer of user data, radio channel ciphering and deciphering, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity), inter-cell interference coordination, connection setup and release, load balancing, distribution for non-access stratum (NAS) messages, NAS node selection, synchronization, radio access network (RAN) sharing, multimedia broadcast multicast service (MBMS), subscriber and equipment trace, RAN information management (RIM), paging, positioning, and delivery of warning messages. The base stations 102 may communicate directly or indirectly (e.g., through the core network 160) with each other over backhaul links 134 (e.g., X2 interface). The backhaul links 134 may be wired or wireless.
The base stations 102 may wirelessly communicate with the UEs 104. Each of the base stations 102 may provide communication coverage for a respective geographic coverage area 110. There may be overlapping geographic coverage areas 110. For example, the small cell 102′ may have a coverage area 110′ that overlaps the coverage area 110 of one or more macro base stations 102. A network that includes both small cell and macro cells may be known as a heterogeneous network. A heterogeneous network may also include Home Evolved Node Bs (eNBs) (HeNBs), which may provide service to a restricted group known as a closed subscriber group (CSG). The communication links 120 between the base stations 102 and the UEs 104 may include uplink (UL) (also referred to as reverse link) transmissions from a UE 104 to a base station 102 and/or downlink (DL) (also referred to as forward link) transmissions from a base station 102 to a UE 104. The communication links 120 may use multiple-input and multiple-output (MIMO) antenna technology, including spatial multiplexing, beamforming, and/or transmit diversity. The communication links may be through one or more carriers. The base stations 102/UEs 104 may use spectrum up to Y MHZ (e.g., 5, 10, 15, 20, 100 MHZ) bandwidth per carrier allocated in a carrier aggregation of up to a total of Yx MHZ (x component carriers) used for transmission in each direction. The carriers may or may not be adjacent to each other. Allocation of carriers may be asymmetric with respect to DL and UL (e.g., more or less carriers may be allocated for DL than for UL). The component carriers may include a primary component carrier and one or more secondary component carriers. A primary component carrier may be referred to as a primary cell (PCell) and a secondary component carrier may be referred to as a secondary cell (SCell).
The wireless communications system may further include a Wi-Fi access point (AP) 150 in communication with Wi-Fi stations (STAs) 152 via communication links 154 in a 5 GHz unlicensed frequency spectrum. When communicating in an unlicensed frequency spectrum, the STAs 152/AP 150 may perform a clear channel assessment (CCA) prior to communicating in order to determine whether the channel is available.
The small cell 102′ may operate in a licensed and/or an unlicensed frequency spectrum. When operating in an unlicensed frequency spectrum, the small cell 102″ may employ NR and use the same 5 GHZ unlicensed frequency spectrum as used by the Wi-Fi AP 150. The small cell 102′, employing NR in an unlicensed frequency spectrum, may boost coverage to and/or increase capacity of the access network.
The gNodeB (gNB) 180 may operate in millimeter wave (mmW) frequencies and/or near mmW frequencies in communication with the UE 104. When the gNB 180 operates in mmW or near mmW frequencies, the gNB 180 may be referred to as an mmW base station. Extremely high frequency (EHF) is part of the RF in the electromagnetic spectrum. EHF has a range of 30 GHz to 300 GHz and a wavelength between 1 millimeter and 10 millimeters. Radio waves in the band may be referred to as a millimeter wave. Near mmW may extend down to a frequency of 3 GHZ with a wavelength of 100 millimeters. The super high frequency (SHF) band extends between 3 GHZ and 30 GHZ, also referred to as centimeter wave. Communications using the mmW/near mmW radio frequency band has extremely high path loss and a short range. The mmW base station 180 may utilize beamforming 184 with the UE 104 to compensate for the extremely high path loss and short range.
The core network 160 may include a Mobility Management Entity (MME) 162, other MMEs 164, a Serving Gateway 166, a Multimedia Broadcast Multicast Service (MBMS) Gateway 168, a Broadcast Multicast Service Center (BM-SC) 170, and a Packet Data Network (PDN) Gateway 172. The MME 162 may be in communication with a Home Subscriber Server (HSS) 174. The MME 162 is the control node that processes the signaling between the UEs 104 and the core network 160. Generally, the MME 162 provides bearer and connection management. All user Internet protocol (IP) packets are transferred through the Serving Gateway 166, which itself is connected to the PDN Gateway 172. The PDN Gateway 172 provides UE IP address allocation as well as other functions. The PDN Gateway 172 and the BM-SC 170 are connected to the IP Services 176. The IP Services 176 may include the Internet, an intranet, an IP Multimedia Subsystem (IMS), a PS Streaming Service (PSS), and/or other IP services. The BM-SC 170 may provide functions for MBMS user service provisioning and delivery. The BM-SC 170 may serve as an entry point for content provider MBMS transmission, may be used to authorize and initiate MBMS Bearer Services within a public land mobile network (PLMN), and may be used to schedule MBMS transmissions. The MBMS Gateway 168 may be used to distribute MBMS traffic to the base stations 102 belonging to a Multicast Broadcast Single Frequency Network (MBSFN) area broadcasting a particular service, and may be responsible for session management (start/stop) and for collecting eMBMS related charging information.
The base station may also be referred to as a gNB, Node B, evolved Node B (eNB), an access point, a base transceiver station, a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS), an extended service set (ESS), or some other suitable terminology. The base station 102 provides an access point to the core network 160 for a UE 104. Examples of UEs 104 include a cellular phone, a smart phone, a session initiation protocol (SIP) phone, a laptop, a personal digital assistant (PDA), a satellite radio, a global positioning system, a multimedia device, a video device, a digital audio player (e.g., MP3 player), a camera, a game console, a tablet, a smart device, a wearable device, a vehicle, an electric meter, a gas pump, a toaster, or any other similar functioning device. Some of the UEs 104 may be referred to as IoT devices (e.g., parking meter, gas pump, toaster, vehicles, etc.). The UE 104 may also be referred to as a station, a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communications device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, a client, or some other suitable terminology.
At the UE 250, each receiver 254RX receives a signal through its respective antenna 252. Each receiver 254RX recovers information modulated onto an RF carrier and provides the information to the receive (RX) processor 256. The TX processor 268 and the RX processor 256 implement layer 1 functionality associated with various signal processing functions. The RX processor 256 may perform spatial processing on the information to recover any spatial streams destined for the UE 250. If multiple spatial streams are destined for the UE 250, they may be combined by the RX processor 256 into a single OFDM symbol stream. The RX processor 256 then converts the OFDM symbol stream from the time-domain to the frequency domain using a Fast Fourier Transform (FFT). The frequency domain signal comprises a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols on each subcarrier, and the reference signal, are recovered and demodulated by determining the most likely signal constellation points transmitted by the base station 210. These soft decisions may be based on channel estimates computed by the channel estimator 258. The soft decisions are then decoded and deinterleaved to recover the data and control signals that were originally transmitted by the base station 210 on the physical channel. The data and control signals are then provided to the controller/processor 259, which implements layer 3 and layer 2 functionality.
The controller/processor 259 can be associated with a memory 260 that stores program codes and data. The memory 260 may be referred to as a computer-readable medium. In the UL, the controller/processor 259 provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, and control signal processing to recover IP packets from the core network 160. The controller/processor 259 is also responsible for error detection using an ACK and/or NACK protocol to support HARQ operations.
Similar to the functionality described in connection with the DL transmission by the base station 210, the controller/processor 259 provides RRC layer functionality associated with system information (e.g., MIB, SIBs) acquisition, RRC connections, and measurement reporting: PDCP layer functionality associated with header compression/decompression, and security (ciphering, deciphering, integrity protection, integrity verification): RLC layer functionality associated with the transfer of upper layer PDUs, error correction through ARQ, concatenation, segmentation, and reassembly of RLC SDUs, re-segmentation of RLC data PDUs, and reordering of RLC data PDUs: and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto TBs, demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization. Channel estimates derived by a channel estimator 258 from a reference signal or feedback transmitted by the base station 210 may be used by the TX processor 268 to select the appropriate coding and modulation schemes, and to facilitate spatial processing. The spatial streams generated by the TX processor 268 may be provided to different antenna 252 via separate transmitters 254TX. Each transmitter 254TX may modulate an RF carrier with a respective spatial stream for transmission. The UL transmission is processed at the base station 210 in a manner similar to that described in connection with the receiver function at the UE 250. Each receiver 218RX receives a signal through its respective antenna 220. Each receiver 218RX recovers information modulated onto an RF carrier and provides the information to a RX processor 270.
The controller/processor 275 can be associated with a memory 276 that stores program codes and data. The memory 276 may be referred to as a computer- readable medium. In the UL, the controller/processor 275 provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, control signal processing to recover IP packets from the UE 250. IP packets from the controller/processor 275 may be provided to the core network 160. The controller/processor 275 is also responsible for error detection using an ACK and/or NACK protocol to support HARQ operations.
New radio (NR) may refer to radios configured to operate according to a new air interface (e.g., other than Orthogonal Frequency Divisional Multiple Access (OFDMA)-based air interfaces) or fixed transport layer (e.g., other than Internet Protocol (IP)). NR may utilize OFDM with a cyclic prefix (CP) on the uplink and downlink and may include support for half-duplex operation using time division duplexing (TDD). NR may include Enhanced Mobile Broadband (eMBB) service targeting wide bandwidth (e.g. 80 MHz beyond), millimeter wave (mmW) targeting high carrier frequency (e.g. 60 GHZ), massive MTC (mMTC) targeting non-backward compatible MTC techniques, and/or mission critical targeting ultra-reliable low latency communications (URLLC) service.
A single component carrier bandwidth of 100 MHZ may be supported. In one example, NR resource blocks (RBs) may span 12 sub-carriers with a sub-carrier bandwidth of 60 kHz over a 0.125 ms duration or a bandwidth of 15 kHz over a 0.5 ms duration. Each radio frame may consist of 20 or 80 subframes (or NR slots) with a length of 10 ms. Each subframe may indicate a link direction (i.e., DL or UL) for data transmission and the link direction for each subframe may be dynamically switched. Each subframe may include DL/UL data as well as DL/UL control data. UL and DL subframes for NR may be as described in more detail below with respect to
The NR RAN may include a central unit (CU) and distributed units (DUs). A NR BS (e.g., gNB, 5G Node B, Node B, transmission reception point (TRP), access point (AP)) may correspond to one or multiple BSs. NR cells can be configured as access cells (ACells) or data only cells (DCells). For example, the RAN (e.g., a central unit or distributed unit) can configure the cells. DCells may be cells used for carrier aggregation or dual connectivity and may not be used for initial access, cell selection/reselection, or handover. In some cases DCells may not transmit synchronization signals (SS) in some cases DCells may transmit SS. NR BSs may transmit downlink signals to UEs indicating the cell type. Based on the cell type indication, the UE may communicate with the NR BS. For example, the UE may determine NR BSs to consider for cell selection, access, handover, and/or measurement based on the indicated cell type.
The TRPs 308 may be a distributed unit (DU). The TRPs may be connected to one ANC (ANC 302) or more than one ANC (not illustrated). For example, for RAN sharing, radio as a service (RaaS), and service specific AND deployments, the TRP may be connected to more than one ANC. A TRP may include one or more antenna ports. The TRPs may be configured to individually (e.g., dynamic selection) or jointly (e.g., joint transmission) serve traffic to a UE.
The local architecture of the distributed RAN 300 may be used to illustrate fronthaul definition. The architecture may be defined that support fronthauling solutions across different deployment types. For example, the architecture may be based on transmit network capabilities (e.g., bandwidth, latency, and/or jitter). The architecture may share features and/or components with LTE. According to aspects, the next generation AN (NG-AN) 310 may support dual connectivity with NR. The NG-AN may share a common fronthaul for LTE and NR.
The architecture may enable cooperation between and among TRPs 308. For example, cooperation may be preset within a TRP and/or across TRPs via the ANC 302. According to aspects, no inter-TRP interface may be needed/present.
According to aspects, a dynamic configuration of split logical functions may be present within the architecture of the distributed RAN 300. The PDCP, RLC, MAC protocol may be adaptably placed at the ANC or TRP.
The DL-centric subframe may also include a common UL portion 506. The common UL portion 506 may sometimes be referred to as an UL burst, a common UL burst, and/or various other suitable terms. The common UL portion 506 may include feedback information corresponding to various other portions of the DL-centric subframe. For example, the common UL portion 506 may include feedback information corresponding to the control portion 502. Non-limiting examples of feedback information may include an ACK signal, a NACK signal, a HARQ indicator, and/or various other suitable types of information. The common UL portion 506 may include additional or alternative information, such as information pertaining to random access channel (RACH) procedures, scheduling requests (SRs), and various other suitable types of information.
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In some circumstances, two or more subordinate entities (e.g., UEs) may communicate with each other using sidelink signals. Real-world applications of such side link communications may include public safety, proximity services, UE-to-network relaying, vehicle-to-vehicle (V2V) communications, Internet of Everything (IoE) communications, IoT communications, mission-critical mesh, and/or various other suitable applications. Generally, a sidelink signal may refer to a signal communicated from one subordinate entity (e.g., UE1) to another subordinate entity (e.g., UE2) without relaying that communication through the scheduling entity (e.g., UE or BS), even though the scheduling entity may be utilized for scheduling and/or control purposes. In some examples, the sidelink signals may be communicated using a licensed spectrum (unlike wireless local area networks, which typically use an unlicensed spectrum).
In this example, the base station 702 transmits RF signals on the time-frequency resource (f, t)1 (e.g., CC1). The UE 704 receives the RF signals from the base station 702 through a channel 710, which can be represented as H1. The repeater 706 receives the RF signals from the base station 702 through a channel 712, which can be represented as H2. The repeater 706 can amplify and forward the RF signals received. Further, the repeater 706 shifts or translates the frequency of the RF carrier to a time-frequency resource (f, t)2 (e.g., CC2). The repeater 706 transmits RF signals on the time-frequency resource (f, t)2. The UE 704 receives, on the time-frequency resource (f, t)2, the RF signals transmitted at the repeater 706 through a channel 714, which can be represented as H3.
The repeater 706 create an indirect data path to improve the data signal quality for the UE 704. In this setup, the base station 702 first transmits data to the repeater 706 on (f, t)1. The repeater 706 then implements frequency translation: it forwards the received data from (f, t)1 to (f, t)2 and transmits the data to the UE 704 on (f, t)2. This additional indirect data path via the repeater 706 can boost the signal quality for the UE 704 through several techniques. Firstly, the repeater 706 can leverage advanced beamforming techniques on the multiple antennas it has to improve reception of the signal from the base station 702 on (f, t)1. Secondly, the repeater 706 can adjust its transmission power to the UE 704 on (f, t)2 based on path loss measurements to ensure an optimal signal level. Next, (f, t)2 may have more favorable propagation conditions to the UE 704 compared to (f, t)1 from the base station 702. Finally, the UE 704 can combine the signals received from both the direct path on (f, t)1 and the indirect path on the (f, t)2 to get diversity gain.
The repeater 706 and/or the UE 704 may receive control information via one or more control paths. In certain configurations, the base station 702 may send control information 720 to the UE 704 through a control path 730 and send control information 722 to the repeater 706 through a control path 732. In certain configurations, the repeater 706 may rely on the UE 704 to obtain the control information 722 through a control path 734.
The control information 720 and 722 contain configurations for the UE 704 and repeater 706 respectively. For the UE 704, the control information 720 configures reference signals in the second time-frequency resource (f, t)2 that the UE 704 can measure. This allows the UE to estimate the channel conditions on the indirect path via the repeater. It also contains instructions to guide the UE's path selection between the direct and indirect paths.
For the repeater 706, the control information 722 includes parameters to control the repeater's behavior. This includes power control levels, beamforming configurations, enabling/disabling frequency translation etc. It provides the mapping rule to translate signals from (f, t)1 to (f, t)2. It also configures reference signals in (f, t)1 that allow the repeater to estimate the channel between itself and the base station.
As such, the control information 720 and 722 include one or more of the below items:
When the repeater 706 repeater does not have cellular connectivity, the control path 734 allows the UE 704 to directly control and configure the repeater 706. The UE 704 can leverage technologies like WiFi, Bluetooth or sidelink to send control information to the repeater such as beamforming configurations and resource allocation instructions. This control path is essential since the repeater may need to rely on the UE 704 for coordination given its lack of direct network access.
When the repeater 706 repeater has cellular connectivity, the control path 732 between the base station 702 and the repeater 706 uses the standard licensed cellular interface. Over this channel, the base station 702 can send important control information to the repeater around parameters like transmission power levels and beamforming coefficients. This allows the network to directly coordinate the repeater behavior as needed.
For example, the repeater may be informed the reference signal configuration via the control path 732 or the control path 734, so that it can 1) measure channel quality between the base-station and the repeater, or 2) derive proper Rx and/or Tx beamforming for signal forwarding based on measurement on the reference signal.
The control path 730 between the base station 702 and the UE 704 may be a regular cellular control path using the standard Uu interface. On this path, the base station 702 can send control signaling to the UE 704 in aspects such as path selection and CSI configuration. The UE 704 may send, on the control path 730, information such as path selection outcomes and capability reports to the network.
In a first technique, the repeater 706 is capable of directly communicating with the base station 702. This technique utilizes a network-controlled flow for controlling the repeater 706's behavior. The repeater 706 and the UE 704 may report their capabilities to the base station 702. The base station 702 configures and transmits reference signals to allow the repeater 706 and the UE 704 to measure channel conditions. Based on the channel measurements, the base station 702 transmits control information to the repeater 706 and the UE 704 regarding parameters like transmission power, beamforming, frequency translation, etc. The base station 702 transmits data to the wearable 704, which may directly receive it or receive it via the repeater 706 depending on path selection.
In the network-controlled flow, the base station configures reference signals in (f, t)1 and/or (f, t)2 for the repeater and UE to measure the channel conditions. After receiving the reference signal measurements from the repeater and UE, the base station determines the control information 722 and 720 to control the transmission powers, beamforming configurations, frequency translation enabling/disabling, number of maximal allowable spatial layers for forwarding, and resource mapping in the repeater. The base station also indicates to the UE whether to receive data via the direct path, indirect path, or both paths combined.
In a second technique, the repeater 706 is not capable of directly communicating with the base station 702. This technique utilizes a UE-controlled flow for controlling the repeater 706's behavior. The UE 704 first sends a request signaling to the repeater 706 to ask the repeater 706 to transmit (forward) data in the second time-frequency resource (f, t)2. After receiving the request from the UE 704, the repeater 706 sends a response back to the UE 704 to acknowledge the request for transmission in (f, t)2.
The UE 704 then delivers control information to the repeater 706 for data transmission. The control information includes: transmission power indicator for the repeater 706 in (f, t)2: Rx/Tx beamforming information for the repeater 706; number of maximal allowable spatial layers for forwarding for the repeater 706; Frequency-translation/mode-switching indicator for the repeater 706: and/or RS configuration or CSI report configuration.
The control information may be delivered via sidelink or WiFi between the UE 704 and repeater 706. After receiving the control information, the repeater 706 transmits data in the second time-frequency resource (f, t)2. The repeater 706 may send the forwarded data in resources reserved by the UE 704 in (f, t)2. To decide which path is better, the UE 704 and repeater 706 may exchange CSI measurement reports. For example, the repeater 706 sends its report to the UE 704, and the UE 704 decides whether frequency translation in the repeater 706 should be enabled.
In the UE-controlled flow; the repeater does not have cellular connectivity and cannot directly receive control information from the base station. The UE requests the repeater to forward data in (f, t)2 and sends control information to the repeater regarding transmission power, beamforming. frequency translation enabling/disabling, and resource reservation in (f, t)2. To allow the repeater to measure the channel conditions, the UE provides reference signal configurations to the repeater. The repeater can derive necessary information to facilitate its forwarding based on the measurement, e.g., beamforming parameters used for forwarding. The repeater can also report channel measurements to the UE to assist in determining whether to use the repeater's forwarding.
As described supra, there are three paths for data transmission from the base station 702 to the UE 704. The first one is a direct path 740. The data is transmitted from the base station 702 to the UE 704 directly in the first time-frequency resource (f, t)1. The second one is an indirect path 742. The data is transmitted from the base station 702 to the repeater 706 in the first time-frequency resource (f, t)1. The repeater 706 translates the received data to the second time-frequency resource (f, t)2 and transmits the data to the UE 704 in (f, t)2. The third one is a combination path 744. The same data is transmitted through the direct path 740 and the indirect path 742 to the UE 704. The signals from the two paths are combined in baseband by the UE 704 in analog domain before baseband processing (such as MIMO decoding).
The antenna capability may include details about the repeater 706's antenna system. This could involve the type of antennas being used, their characteristics (e.g., directional or omnidirectional), and how the antennas are configured. The antenna capability may include details such as the number of receive antennas and the number of transmit antennas (e.g., it has 4 receive antennas and 4 transmit antennas, or may be 4 receive antennas but only 2 transmit antennas).
The antenna configuration of the repeater impacts how the repeater can shape and process the signals when receiving from the base station and forwarding to the UE. For example, more antennas allow the repeater to perform beamforming to optimize the signals. The base station can determine how best to utilize the repeater and configure the transmission and reception beamforming patterns appropriately.
The repeater 706 reports the frequency range (in this case, the translated frequency range) that it is capable of using for the second time-frequency resource (f, t)2. This range is essential for coordination and ensuring that the base station 702 and repeater 706 are operating within compatible frequency bands.
The UE 704 sends the base station 702 a capability report 812 and reports its capability for path selection and supported frequency range(s) for the second time-frequency resource (f, t)2. Path selection refers to the ability of the UE 704 to choose between different paths or routes for its communication with the base station 702. This might include the UE 704's ability to determine which relay or repeater node it should communicate with to optimize signal quality or other performance criteria. The UE 704 reports the range of frequencies it can operate on or communicate with. In this case, it's indicating its supported frequency range for the second time-frequency resource (f, t)2. This information helps the base station 702 understand the frequencies at which the UE 704 can send and receive signals.
The base station 702 indicates reference signal (RS) resource configuration 820 to the repeater 706 for measurement in the first time-frequency resource (f, t)1. This lets the repeater 706 measure the channel 712's conditions on the first time-frequency resource (f, t)1. The measurement is used to determine Rx beamforming of the repeater 706. The RS resource configuration 820 may also inform the repeater 706 to generate RS and transmit the RS to the UE 704 in the second time-frequency resource (f, t)2.
The base station 702 indicates, on (f, t)1, reference signal (RS) resource configuration 822 to the UE 704 for measurement on the second time-frequency resource (f, t)2. This lets the UE 704 measure the channel 714's conditions in the second time-frequency resource (f, t)2. The base station 702 configures RS resource for the UE 704. The RS will be transmitted by the repeater 706 on the second time-frequency resource (f, t)2. The measurement is used to determine transmit power in the second time-frequency resource (f, t)2 or Tx beamforming of the repeater 706. The base station 702 transmits RS 830 to the repeater 706 on the first time-frequency resource (f, t)1. The repeater 706 measures the RS 830 according to the RS resource configuration 820 and generates RS measurement report 840. The repeater 706 transmits the RS measurement report 840 to the base station 702. This measurement may be used to determine receive beamforming parameters for the repeater 706. By analyzing the channel conditions from the base station 702 to the repeater 706, the optimal receive beamforming scheme (e.g. antenna selection, combining weights etc.) can be determined. This measurement procedure can leverage legacy NR specifications. The base station can configure CSI resources and request CSI reports from the repeater 706, since the repeater 706 is connected to the network. Therefore, the repeater 706 can measure RS, calculate CSI, and feed back reports to the base station 702 using existing NR signaling. The base station 702 can then determine suitable receive beamforming for the repeater 706 based on the CSI reports, or the repeater can determine suitable receive beamforming by itself based on the measurement of RS.
The repeater 706 generates RS 832 according to the RS resource configuration 820 and transmits the RS 832 to the UE 704 in the second time-frequency resource (f, t)2. The UE 704 measures the RS 832 according to the RS resource configuration 822 and generates RS measurement report 842. The UE 704 transmits the RS measurement report 842 to the base station 702. This measurement may be used to determine the transmit power of the repeater 706 on (f, t)2. By measuring the channel conditions from the repeater 706, the UE 704 can determine an appropriate transmit power for the repeater 706 on (f, t)2. This measurement may be used to determine Tx beamforming of the repeater 706. By analyzing the channel conditions, the UE 704 can determine optimal beamforming parameters (e.g. antenna selection, precoding matrix etc.) for the repeater 706's transmission on (f, t)2.
According to the received RS measurement report 840 (for segment from the base station 702 to the repeater 706) and RS measurement report 842 (for segment from the repeater 706 to the UE 704), the base station 702 may estimate the end-to-end quality from the base station 702 to the UE 704 through the indirect path. The UE 704 may measure reference signals from the base station 702 on (f, t)1 to get the direct path quality rely on normal CSI feedback that the UE 704 sends to the base station 702.
By comparing the channel quality of the direct path and the indirect path, the base station 702 may select a path and informs the path selection to the UE 704 by transmitting the control information 720.
In this first technique implementing the network-controlled flow, the base station 702 transmits control information 722 to the repeater 706. This control information contains parameters to control the behavior of the repeater 706 when it receives signals on the first time-frequency resource (f, t)1 and forwards them to the second time-frequency resource (f, t)2 for transmission to the UE 704. As discussed, the repeater 706 assists in communication between the base station 702 and the UE 704 by receiving signals on (f, t)1 and forwarding them on (f, t)2 after frequency translatings.
The control information 722 from the base station 702 to the repeater 706 includes one or more of the following:
In addition, the base station 702 sends control information 720 to the UE 704. This includes:
After transmitting the control information, the base station 702 sends its data transmission intended for the UE 704 on (f, t)1. The UE 704 then receives the data either directly on (f, t)1 or indirectly forwarded by the repeater 706 on (f, t)2, depending on path selection.
In this example, the indirect path 742 is selected. The base station 702 transmits reference signals on (f, t)1. The repeater 706 then forwards the reference signals from (f, t)1 to (f, t)2 through frequency translating. After the reference signals are forwarded to the (f, t)2, the repeater 706 transmits the reference signals to the UE 704. The UE 704 then reports the reference signal measurements to the base station 702 corresponding to the signals received on (f, t)2.
At this point, the base station 702 needs an end-to-end CSI report since the path has already been selected. The CSI report should reflect the actual selected path, either direct or indirect. For example, if the direct link was selected, the UE 704 should measure reference signals on (f, t)1. But if the indirect link was selected, the UE 704 should measure on (f, t)2 to provide an end-to-end CSI covering the path through the repeater 706. This allows the base station 702 to get channel state information reflecting the full selected path.
The UE 704 first sends a request 950 the repeater 706 to ask the repeater 706 to transmit (forward) data in the second time-frequency resource (f, t)2. After receiving the request from the UE 704, the repeater 706 sends a response 952 back to the UE 704 to acknowledge the request for transmission in (f, t)2.
The UE 704 may reserve resources for the repeater 706 to transmit data or reference signals in the second time-frequency resource (f, t)2.
If (f, t)2 is in the unlicensed band, then the UE 704 may need to explicitly reserve resources before the repeater 706 can transmit. This is because in the unlicensed band, the channel is shared and the repeater cannot freely transmit without risk of collision.
By reserving certain resources in (f, t)2 ahead of time, the UE 704 ensures there will be allocated slots that the repeater 706 can transmit in without interference from other devices. This reservation step may be unnecessary if (f, t)2 is in the licensed band, since transmissions are better coordinated.
Overall, this allows the UE 704 to grant transmission opportunities to the repeater 706 in the second time-frequency resource (f, t)2. This is important to enable the repeater to forward data and reference signals back to the UE as part of the UE-controlled flow procedure.
In the licensed band, the UE 704 can reserve, with the base station 702, certain time-frequency resources in (f, t)2 for the repeater 706 to transmit data or RS to the UE 704. This reservation gives allocated resources for the repeater 706 to transmit in without collisions. However, if (f, t)2 is in the unlicensed band, reservation may not be needed. In the unlicensed band, devices can transmit whenever the channel is free.
The UE 704 then sends control information 722 to the repeater 706 for data transmission. In certain configurations, some or all of the control information 722 may be generated at the base station 702 and sent to the UE 704. The rest of the control information 722 may be determined by the UE 704. The control information 722 includes at least one of the following items:
Since the repeater 706 does not have cellular connectivity in the UE-controlled flow, it cannot directly receive control information from the base station 702. The UE 704 provides sufficient RS and CSI configurations to the repeater 706. The control information may be delivered via sidelink or WiFi between the UE 704 and the repeater 706.
After receiving the control information, the repeater 706 transmits data in the second time-frequency resource (f, t)2. The repeater 706 sends the forwarded data in resources reserved by the UE 704 in (f, t)2.
To decide the better path quality for path selection, the UE 704 and the repeater 706 may exchange CSI reports with each other. For example, the repeater 706 sends its report to the UE 704, and the UE 704 decides whether frequency translation in the repeater 706 should be enabled.
The RS resource configuration 1010/1012 is configured by the base station 702 for the repeater 706. The configuration indicates the RS resources (e.g. locations in time/frequency) that the repeater 706 should measure in order to generate a CSI report 1040. This allows the repeater 706 to measure the channel between itself and the base station. The RS resource configuration 1020 is configured by the base 702 station for the UE 704. The configuration indicates the RS resources that the UE 704 should measure to generate its own CSI report 1042. This allows the UE to measure the direct channel between itself and the base station. Both RS resource configurations are in the first time-frequency resource (f, t)1. This allows both the repeater and UE to measure the channels associated with the base station's transmission in (f, t)1. By configuring the specific RS resources to be measured, the base station 702 enables the repeater 706 and the UE 704 to obtain channel measurements over the direct and indirect paths which can be compared for optimal path selection.
The CSI report configurations 1014/1016 and 1022 specifies the format and contents of the CSI reports that will be generated and transmitted by the repeater 706 and the UE 704 based on their reference signal measurements. More specifically: The CSI report configuration 1014/1016 is for the repeater indicates how the repeater should format and populate the CSI report 1040 that will be sent to the base station. This includes details like what metrics (rank, precoding, quality, etc.) to include and how to structure the report packet. The CSI report configuration 1022 provides similar instructions on how the UE should generate and format its own CSI report 1042 to send to the base station. The CSI report configurations allow the base station to instruct the repeater 706 and the UE 704 to generate compatible/comparable CSI reports. This is important so that the UE can compare the two reports when determining path selection. The CSI report configurations provide details such as report contents, timing, resource mapping, quantization, etc. so that the base station receives useful and consistent channel state information from both sides.
The base station 702 transmits RS 1030 to the repeater 706 on (f, t)1. The repeater measures the RS 1030 according to the RS resource configuration 1010/1012 and generates a CSI measurement report 1040 according to the CSI report configuration 1014/1016. The CSI report may contain information such as rank, precoding, channel quality, and path loss. The repeater 706 transmits the CSI measurement report 1040 to the base station 702.
The base station 702 transmits RS 1032 to the UE 704 on (f, t)1. The UE measures the RS 1032 according to the RS resource configuration 1020 and generates a CSI measurement report 1042 according to the CSI report configuration 1022.
To make a path selection decision, the UE 704 needs to obtain the CSI report 1040 from the repeater 706 and compare it to its own CSI report 1042. In a first approach, the base station 702 sends the CSI report 1040 to the UE 704. In a first scenario, the base station 702 sends the CSI report 1040 directly to the UE 704 on (f, t)1. In a second scenario, the base station 702 transmits the CSI report 1040 to the repeater 706 on (f, t)1. The repeater 706 forwards the report to the UE 704 on (f, t)2 after frequency translation. In a second approach, the repeater 706 sends the CSI report 1040 to the UE 704 directly on (f, t)2.
After obtaining both CSI reports, the UE 704 compares them and performs path selection. By comparing the two CSI reports, the UE 704 can determine whether the direct or indirect (through repeater) path provides better channel quality. The UE 704 selects the direct path 740 if its own CSI report 1042 is much better than the repeater 706's CSI report 1040. The UE 704 selects the indirect path 742 if the opposite is true. That is, if the repeater 706's CSI report indicates a strong channel, the indirect path is likely to be better, so the UE 704 would select that path.
Subsequently, the UE 704 sends a path selection report 1050 to the base station 702 to indicate its selection.
The base station 702 transmits RS 1120 to the repeater 706 on (f, t)1. The repeater forwards this to the UE 704 on (f, t)2 after frequency translation. The UE 704 measures this to obtain RS measurement 1122.
Having obtained both RS measurements 1112 and 1122, the UE 704 compares them and performs path selection accordingly. The UE 704 selects the direct path 740 if RS measurement 1112 is much better than RS measurement 1122. The UE 704 selects the indirect path 742 if the opposite is true. The UE 704 sends a path selection report 1150 to the base station 702 indicating its selection.
If the direct path 740 is selected, after the UE 704 receiving the control information 720 from the base station 702 or after the UE 704 performing the path selection itself, the UE 704 performs data decoding according to its received signal on the first time-frequency resource (f, t)1. The repeater 706 is instructed through the control information 722 to not forward data in the second time-frequency resource (f, t)2.
If the indirect path 742 is selected, after the UE 704 receiving the control information 720 from the base station 702 or after the UE 704 performing the path selection itself, the UE 704 performs data decoding according to its received signal on the second time-frequency resource (f, t)2. The repeater 706 are instructed through the control information 722 to enable frequency translation from the first time-frequency resource (f, t)1 to the second time-frequency resource (f, t)2 and data forwarding on the second time-frequency resource (f, t)2.
In certain configurations, the UE 704 may only have the capability to or choose to process signals received/transmitted on one component carrier (CC) at a time. It does not simultaneously process multiple CCs.
The UE 704 may be able to receive RF signals on both (f, t)1 and (f, t)2 simultaneously, but may not be able to process RF signals of both (f, t)1 and (f, t)2 simultaneously. If the combination path 744 is selected, after the UE 704 receiving the control information 720 from the base station 702 or after the UE 704 performing the path selection itself, the UE 704 receives the same data signal from both (f, t)1 and (f, t)2. The RF signal received from (f, t)2 is frequency shifted to (f, t)1. Then, the two RF signals on (f, t)1 are combined in the analog domain. The combined RF signal is then converted to a single combined baseband signal before being passed to baseband processing such as 1 CC MIMO decoding. Combining the signals in analog domain after frequency shifting provides better signal quality compared to selecting only one path.
Alternatively, the UE 704 can either receive the signal from (f, t)1 directly from the base station 702, or receive the signal forwarded by the repeater 706 on (f, t)2. In this case, the UE 704 would select only one path out of the two. The path selection decision is either made by the network or by the UE 704 itself based on comparing channel conditions. After selecting a single path, the UE 704 would perform data decoding according to the signal received on the selected path. This allows the UE 704 with limited processing capability to still benefit from the repeater assisted setup by switching between the better quality path. The UE 704 relies on the network or makes decisions itself on whether to receive data from (f, t)1 or (f, t)2. The UE 704 does not receive data from (f, t)1 and (f, t)2 together. After path selection, the UE performs data decoding on the signal received only on the selected CC.
In a first method, the UE 704 transmits sounding reference signal (SRS) (or other suitable RS) 1310 to the repeater 706 in the second time-frequency resource (f, t)2 for measurement.
In a first option, the repeater 706 measures the SRS 1310 and generates a RS measurement report 1320. The repeater 706 then transmits the RS measurement report 1320 to the UE 704 on (f, t)2. The UE 704 decides the transmission power for the repeater 706 based on the RS measurement report 1320, and transmitting control information 1330 including the transmission power to the repeater 706.
In a second option, after measuring the RS received from the UE 704, the repeater 706 can decide the transmission power itself based on the RS measurement result 1340 without needing to send a report back to the UE.
In a second method, the UE 704 transmits control information 1350 which indicates the reserved resource and the initial transmission power for RS transmission from the repeater 706 in (f, t)2. The repeater 706 then transmits RS 1360 in (f, t)2 on the indicated reserved resource with the indicated transmission power according to the control information 1350 from the UE. The UE 704 measures the received RS 1360 and decides the transmission power for the repeater 706 for transmitting data in (f, t)2 based on the RS measurement result 1370. The UE 704 informs the transmission power to the repeater 706 by transmitting control information 1380.
In a first configuration, the repeater 706 may be configured with a data set represented by the below Table 1.
Each indicator index corresponds to a particular transmission power level on (f, t)2 or a maximum allowable transmission power level on (f, t)2. The value of the transmission power indicator in the control information 722 corresponds to the value of the index. For example, if the indicator index signaled is 1, then the controller 1410 controls the transmitter 1420 to transmit RF signals 1460 with power Pl on (f, t)2 based on the mapping shown in the Table 1. Similarly, if the indicator index is 2, then the controller 1410 controls the transmitter 1420 to transmit the RF signals 1460 with power P2 on (f, t)2. An indicator index of 0 means the repeater should transmit with zero power (i.e. no transmission). Similarly, the indicated index may be interpreted as an indication of a maximum allowable transmission power level of the transmitter on (f, t)2.
By signaling different indicator index values, the UE (or network) can control the repeater's transmission power in a fine-grained manner. The actual power levels P1 and P2 would be predetermined based on link measurements and adaptations.
In a second configuration, the repeater 706 may be configured with a data set represented by the below Table 2.
In this configuration, the indicator indexes specify a relative power adjustment rather than an absolute value.
For example, if the indicator index is 1, it means that the controller 1410 control the transmitter 1420 to increase its current transmission power by P1. If the index is 2, the controller 1410 should control the transmitter 1420 decrease its current power by P2. An index of 0 means no changes in transmission power.
By signaling relative power adjustments in this manner, the UE (or network) can incrementally control the repeater's power without needing to re-signal the entire absolute value each time. The adjustments P1 and P2 would be predetermined optimal step sizes.
Further, the control information 722 may include a frequency translation indicator, which indicates whether frequency translation from (f, t)1 to (f, t)2 should be enabled or disabled. The repeater 706 may be configured with a data set represented by the below Table 3.
The frequency translation indicator index 1 indicates for enabling frequency translation. The repeater 706 receives data from the base station 702 in the first time-frequency resource (f, t)1, and frequency-translates the received data to the second time-frequency resource (f, t)2. After translation of data from the first time-frequency resource (f, t)1 to the second time-frequency resource (f, t)2 is finished, the repeater 706 transmits data to the UE 704 in the second time-frequency resource (f, t)2.
In one configuration, the frequency translation indicator index 0 indicates for disabling frequency translation. The repeater 706 does not transmit any data to the UE 704, the UE 704 only receives data from the base station 702. In a second configuration, the frequency translation indicator index 0 indicates that the repeater 706 does not perform frequency translation, but rather performs amplifying-and-forwarding on (f, t)1. That is, the repeater 706 retransmits received data signal to the UE 704 on (f, t)1.
Further, the control information 722 may include an Rx/Tx beamforming scheme indicator. The Rx/Tx beamforming scheme indicator allows the UE 704 (or network) to configure the beamforming behavior of the repeater 706. The repeater 706 can perform beamforming on both its multiple receive antennas when receiving signals from the base station as well as its multiple transmit antennas when forwarding signals to the UE.
The repeater 706 may be configured with a data set represented by the below Table 4.
The indicator value signals which predefined beamforming configuration should be used by the repeater 706 for reception and transmission. For example, if the indicator is 0, the repeater 706 applies the “1st Rx/Tx beamforming” scheme. This refers to a specific set of weights and patterns designed for the repeater's antennas. Similarly, if the indicator is 1, the “2nd Rx/Tx beamforming” scheme is applied, which is a different set of beamforming parameters.
The UE 704 (or network) can switch between beamforming configurations by changing the value of the Rx/Tx beamforming scheme indicator. The defined schemes would be optimized for different channel conditions.
The indicator can jointly control both Rx and Tx beamforming in a single scheme. For example, in Table 4, indicator value 0 maps to a joint “1st Rx/Tx beamforming” scheme that configures both reception and transmission, while value 1 maps to a different joint scheme.
Alternatively, Rx and Tx beamforming can be separately indicated and controlled using two different indicators. This allows more flexible configuration by independently setting the Rx and Tx patterns.
In the linear combining example, the repeater has 4 receive ports and 2 transmit ports. The matrix W shows the mapping from the 4 received signals to the 2 transmitted signals. W linearly combines and weights the received signals to obtain the transmitted signals. This demonstrates a simple beamforming scheme by analog signal combining.
More advanced beamforming techniques based on channel state information and matrix computations can also be indicated. Additionally, the number of transmission layers can be configured to adapt to different rank conditions.
Overall, the beamforming indicator allows the UE (or network) to control the repeater's beamforming in various ways to optimize the overall link quality. The control can range from simple antenna selection to advanced computation-based processing.
An example of SVD (Singular Value Decomposition) based beamforming is shown for the repeater 706. In this example, the—gNB/repeater have 32/2 transmit antenna ports, and the repeater/UE have 4/2 receive antenna ports.
The channel matrix H1 (2×32) represents the MIMO channel from gNB to UE directly. The channel matrix H2 (4×32) represents the MIMO channel from gNB to the repeater. The channel matrix H3 (2×2) represents the MIMO channel from repeater to UE.
SVD decomposition is performed on the matrix Heff=H2H2H as follows:
where U is a matrix with left singular vectors μ1, μ2, μ3, μ4; Σ is a diagonal matrix with singular values ν1, ν2, ν3, ν4; V is a matrix with right singular vectors σ1, σ2, σ3, σ4 in descending order.
The beamforming matrix W is then formed by taking the first 2 columns of U, corresponding to the two largest singular values σ1 and σ2:
where μ1H is Hermitian (conjugate) transpose of 1st column of U: μ2H is Hermitian transpose of 2nd column of U. This W matrix applies the beamforming weights from the 4 repeater receive antennas to the 2 transmit antennas. By taking the conjugate transpose of μ1 and μ2, the highest gain transmit directions are selected to maximize performance. In this example the repeater takes two column vectors for Rx and Tx beamforming, W, because the indirect path can at most contribute two spatial layers for data forwarding. As another example, the column vectors can be two identical vectors if the base-station is sure that the data signal to be forwarded is rank-1:
Thus, the repeater may also need information of maximal number of allowable spatial layers to be forwarded in order to decide Rx and Tx beamforming properly. Equivalently, the maximal number of allowable spatial layers is maximal rank of the beamforming matrix W. Then the base-station or the UE may need to signal to the repeater a maximal number of allowable spatial layers for forwarding. In certain configurations, the Rx/Tx beamforming scheme indicator corresponds to different predefined SVD beamforming configurations optimized for various channel conditions. For example:
As such, different indicator values mapping to different SVD configurations. The UE/Network signals the indicator to choose which pre-computed SVD beamforming matrix to use. The repeater would then apply the Rx/Tx beamforming according to the specified W matrix. This allows adaptive SVD beamforming by changing the indicator value instead of re-computing the SVD every time. The UE/Network can choose the optimal scheme for current conditions.
In operation 1502, the base station configures first reference signals on a first time-frequency resource for a second wireless device (e.g., the repeater 706) to measure channel conditions between the base station and the second wireless device.
In operation 1504, the base station configures second reference signals on a second time-frequency resource for a first wireless device (e.g., the UE 704) to measure channel conditions between the base station and the second wireless device. In certain configurations, the first time-frequency resource and the second time-frequency resource are within a same band or a same component carrier.
In operation 1506, the base station transmits the first reference signals and the second reference signals. In operation 1508, the base station receives, from the second wireless device, first measurements of the first reference signals. In certain configurations, the first measurements comprise at least one of: a rank indicator: a precoding matrix indicator: a channel quality indicator: and a path loss estimate.
In operation 1510, the base station receives, from the first wireless device, second measurements of the second reference signals. In operation 1512, the base station selects a communication path, for communicating data between the base station and the first wireless device, from a direct path between the base station and the first wireless device and an indirect path between the base station and the first wireless device via the second wireless device based at least in part on the received first measurements and second measurements.
In certain configurations, to select the communication path, the base station may compare a quality of the direct path derived from the first measurements with a quality of the indirect path derived from the second measurements. The indirect path may be selected when the quality of the indirect path is higher than the quality of the direct path.
In operation 1514, the base station transmits control information to the first wireless device indicating the communication path for communicating data with the base station. In certain configurations, the control information further indicates to the first wireless device to calculate channel state information on the communication path.
In certain configurations, the base station transmits the data to the first wireless device via the communication path.
In operation 1606, the first wireless device obtains second measurements for an indirect path between the base station and the first wireless device via a second wireless device. The first wireless device may receive a configuration of second reference signals on a second time-frequency resource from the base station. The first wireless device then measures the second reference signal on the second time-frequency resource to obtain the second measurements. The second reference signal is transmitted from the base station on the first time-frequency resource and received via the second wireless device after frequency translation. The measuring of the first and second reference signals may be non-overlapping in time.
In certain configurations, to obtain the second measurements, the first wireless device receives the second measurements from the base station or the second wireless device. The second measurements are generated at the second wireless device.
In operation 1608, the first wireless device selects a communication path from the direct path and the indirect path based at least in part on the first measurements and the second measurements. The first wireless device compares the first measurements of the direct path with the second measurements of the indirect path. The indirect path may be selected when the second measurements indicate higher quality than the first measurements.
The first time-frequency resource and the second time-frequency resource are non-overlapping. The first measurements and second measurements may each comprise one or more of: a rank indicator, a precoding matrix indicator, a channel quality indicator, and a path loss estimate. In operation 1610, the first wireless device transmits an indication of the selected path to the base station.
It is understood that the specific order or hierarchy of blocks in the processes/flowcharts disclosed is an illustration of exemplary approaches. Based upon design preferences, it is understood that the specific order or hierarchy of blocks in the processes/flowcharts may be rearranged. Further, some blocks may be combined or omitted. The accompanying method claims present elements of the various blocks in a sample order, and are not meant to be limited to the specific order or hierarchy presented.
The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects. Thus, the claims are not intended to be limited to the aspects shown herein, but is to be accorded the full scope consistent with the language claims, wherein reference to an element in the singular is not intended to mean “one and only one” unless specifically so stated, but rather “one or more.” The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any aspect described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects. Unless specifically stated otherwise, the term “some” refers to one or more. Combinations such as “at least one of A, B, or C,” “one or more of A, B, or C,” “at least one of A, B, and C,” “one or more of A, B, and C,” and “A, B, C, or any combination thereof” include any combination of A, B, and/or C, and may include multiples of A, multiples of B, or multiples of C. Specifically, combinations such as “at least one of A, B, or C,” “one or more of A, B, or C,” “at least one of A, B, and C,” “one or more of A, B, and C,” and “A, B, C, or any combination thereof” may be A only, B only, C only, A and B, A and C, B and C, or A and B and C, where any such combinations may contain one or more member or members of A, B, or C. All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. The words “module,” “mechanism,” “element,” “device,” and the like may not be a substitute for the word “means.” As such, no claim element is to be construed as a means plus function unless the element is expressly recited using the phrase “means for.”
This application claims the benefits of U.S. Provisional Application Ser. No. 63/384,611, entitled “NETWORK-CONTROLLED APPROACH FOR DEVICE COLLABORATIVE RX/TX FOR DIVERSITY AGGREGATION” and filed on Nov. 22, 2022, which is expressly incorporated by reference herein in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 63384611 | Nov 2022 | US |
