WO2022000356A1

WO2022000356A1 - Sidelink relay power allocation and precoder selection

Info

Publication number: WO2022000356A1
Application number: PCT/CN2020/099622
Authority: WO
Inventors: Hui Guo; Junyi Li; Kapil Gulati; Sourjya Dutta; Shuanshuan Wu
Original assignee: Qualcomm Incorporated
Priority date: 2020-07-01
Filing date: 2020-07-01
Publication date: 2022-01-06

Abstract

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment may receive a message at a first transmission reception point (TRP) controlled by the UE, adjust one or more of a power allocation or a precoder for one or more of the first TRP or a second TRP controlled by the UE, and relay the message to another UE from one or more of the first TRP or the second TRP after adjusting the one or more of the power allocation or the precoder. Numerous other aspects are provided.

Description

SIDELINK RELAY POWER ALLOCATION AND PRECODER SELECTION

FIELD OF THE DISCLOSURE

Aspects of the present disclosure generally relate to wireless communication and to techniques and apparatuses for sidelink relay power allocation and precoder selection.

BACKGROUND

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 (e.g., bandwidth, transmit power, and/or the like) . 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, time division synchronous code division multiple access (TD-SCDMA) systems, and Long Term Evolution (LTE) . LTE/LTE-Advanced is a set of enhancements to the Universal Mobile Telecommunications System (UMTS) mobile standard promulgated by the Third Generation Partnership Project (3GPP) .

A wireless network may include a number of base stations (BSs) that can support communication for a number of user equipment (UEs) . A user equipment (UE) may communicate with a base station (BS) via the downlink and uplink. The downlink (or forward link) refers to the communication link from the BS to the UE, and the uplink (or reverse link) refers to the communication link from the UE to the BS. As will be described in more detail herein, a BS may be referred to as a Node B, a gNB, an access point (AP) , a radio head, a transmit receive point (TRP) , a New Radio (NR) BS, a 5G Node B, and/or the like.

The above multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different user equipment to communicate on a municipal, national, regional, and even global level. New Radio (NR) , which may also be referred to as 5G, is a set of enhancements to the LTE mobile standard promulgated by the Third Generation Partnership Project (3GPP) . NR is designed to better support mobile broadband Internet access by improving spectral efficiency, lowering costs, improving services, making use of new spectrum, and better integrating with other open standards using orthogonal frequency division multiplexing (OFDM) with a cyclic prefix (CP) (CP-OFDM) on the downlink (DL) , using CP-OFDM and/or SC-FDM (e.g., also known as discrete Fourier transform spread OFDM (DFT-s-OFDM) ) on the uplink (UL) , as well as supporting beamforming, multiple-input multiple-output (MIMO) antenna technology, and carrier aggregation. As the demand for mobile broadband access continues to increase, further improvements in LTE, NR, and other radio access technologies remain useful.

SUMMARY

In some aspects, a method of wireless communication performed by a user equipment (UE) may include receiving a message at a first transmission reception point (TRP) controlled by the UE, adjusting one or more of a power allocation or a precoder for one or more of the first TRP or a second TRP controlled by the UE, and relaying the message to another UE from one or more of the first TRP or the second TRP after adjusting the one or more of the power allocation or the precoder.

In some aspects, a UE for wireless communication may include a memory and one or more processors operatively coupled to the memory. The memory and the one or more processors may be configured to receive a message at a first TRP controlled by the UE, adjust one or more of a power allocation or a precoder for one or more of the first TRP or a second TRP controlled by the UE, and relay the message to another UE from one or more of the first TRP or the second TRP after adjusting the one or more of the power allocation or the precoder.

In some aspects, a non-transitory computer-readable medium storing a set of instructions for wireless communication may include one or more instructions that, when executed by one or more processors of a UE, cause the UE to receive a message at a first TRP controlled by the UE, adjust one or more of a power allocation or a precoder for one or more of the first TRP or a second TRP controlled by the UE, and relay the message to another UE from one or more of the first TRP or the second TRP after adjusting the one or more of the power allocation or the precoder.

In some aspects, an apparatus for wireless communication may include means for receiving a message at a first TRP controlled by the apparatus, means for adjusting one or more of a power allocation or a precoder for one or more of the first TRP or a second TRP controlled by the apparatus, and means for relaying the message to another apparatus from one or more of the first TRP or the second TRP after adjusting the one or more of the power allocation or the precoder.

Aspects generally include a method, apparatus, system, computer program product, non-transitory computer-readable medium, user equipment, base station, wireless communication device, and/or processing system as substantially described herein with reference to and as illustrated by the drawings, specification, and appendix.

The foregoing has outlined rather broadly the features and technical advantages of examples according to the disclosure in order that the detailed description that follows may be better understood. Additional features and advantages will be described hereinafter. The conception and specific examples disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present disclosure. Such equivalent constructions do not depart from the scope of the appended claims. Characteristics of the concepts disclosed herein, both their organization and method of operation, together with associated advantages will be better understood from the following description when considered in connection with the accompanying figures. Each of the figures is provided for the purposes of illustration and description, and not as a definition of the limits of the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the above-recited features of the present disclosure can be understood in detail, a more particular description, briefly summarized above, may be had by reference to aspects, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only certain typical aspects of this disclosure and are therefore not to be considered limiting of its scope, for the description may admit to other equally effective aspects. The same reference numbers in different drawings may identify the same or similar elements.

Fig. 1 is a diagram illustrating an example of a wireless network, in accordance with various aspects of the present disclosure.

Fig. 2 is a diagram illustrating an example of a base station in communication with a user equipment (UE) in a wireless network, in accordance with various aspects of the present disclosure.

Fig. 3 is a diagram illustrating an example of sidelink communications, in accordance with various aspects of the present disclosure.

Fig. 4 is a diagram illustrating an example of sidelink communications and access link communications, in accordance with various aspects of the present disclosure.

Fig. 5 is a diagram illustrating an example of sidelink relaying, in accordance with various aspects of the present disclosure.

Fig. 6 is a diagram illustrating an example of sidelink resources, in accordance with various aspects of the present disclosure.

Fig. 7 is a diagram illustrating an example of a vehicle with multiple transmission reception points (TRPs) , in accordance with various aspects of the present disclosure.

Fig. 8 is a diagram illustrating an example of sidelink relaying with multiple TRPs, in accordance with various aspects of the present disclosure.

Fig. 9 is a diagram illustrating an example of sidelink relaying with multiple TRPs, in accordance with various aspects of the present disclosure.

Fig. 10 is a diagram illustrating an example of sidelink relaying with multiple TRPs, in accordance with various aspects of the present disclosure.

Fig. 11 is a diagram illustrating an example of sidelink relaying with multiple TRPs, in accordance with various aspects of the present disclosure.

Fig. 12 is a diagram illustrating an example process performed, for example, by a UE, in accordance with various aspects of the present disclosure.

DETAILED DESCRIPTION

Various aspects of the disclosure are described more fully hereinafter with reference to the accompanying drawings. This disclosure may, however, be embodied in many different forms and should not be construed as limited to any specific structure or function presented throughout this disclosure. Rather, these aspects are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. Based on the teachings herein, one skilled in the art should appreciate that the scope of the disclosure is intended to cover any aspect of the disclosure disclosed herein, whether implemented independently of or combined with any other aspect of the disclosure. For example, an apparatus may be implemented or a method may be practiced using any number of the aspects set forth herein. In addition, the scope of the disclosure is intended to cover such an apparatus or method which is practiced using other structure, functionality, or structure and functionality in addition to or other than the various aspects of the disclosure set forth herein. It should be understood that any aspect of the disclosure disclosed herein may be embodied by one or more elements of a claim.

Several aspects of telecommunication systems will now be presented with reference to various apparatuses and techniques. These apparatuses and techniques will be described in the following detailed description and illustrated in the accompanying drawings by various blocks, modules, components, circuits, steps, processes, algorithms, and/or the like (collectively referred to as “elements” ) . These elements may be implemented using hardware, software, or combinations thereof. Whether such elements are implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system.

It should be noted that while aspects may be described herein using terminology commonly associated with a 5G or NR radio access technology (RAT) , aspects of the present disclosure can be applied to other RATs, such as a 3G RAT, a 4G RAT, and/or a RAT subsequent to 5G (e.g., 6G) .

Fig. 1 is a diagram illustrating an example of a wireless network 100, in accordance with various aspects of the present disclosure. The wireless network 100 may be or may include elements of a 5G (NR) network, an LTE network, and/or the like. The wireless network 100 may include a number of base stations 110 (shown as BS 110a, BS 110b, BS 110c, and BS 110d) and other network entities. A base station (BS) is an entity that communicates with user equipment (UEs) and may also be referred to as an NR BS, a Node B, a gNB, a 5G node B (NB) , an access point, a transmit receive point (TRP) , and/or the like. Each BS may provide communication coverage for a particular geographic area. In 3GPP, the term “cell” can refer to a coverage area of a BS and/or a BS subsystem serving this coverage area, depending on the context in which the term is used.

A BS may provide communication coverage for a macro cell, a pico cell, a femto cell, and/or another type of cell. A macro cell may cover a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by UEs with service subscription. A pico cell may cover a relatively small geographic area and may allow unrestricted access by UEs with service subscription. A femto cell may cover a relatively small geographic area (e.g., a home) and may allow restricted access by UEs having association with the femto cell (e.g., UEs in a closed subscriber group (CSG) ) . A BS for a macro cell may be referred to as a macro BS. A BS for a pico cell may be referred to as a pico BS. A BS for a femto cell may be referred to as a femto BS or a home BS. In the example shown in Fig. 1, a BS 110a may be a macro BS for a macro cell 102a, a BS 110b may be a pico BS for a pico cell 102b, and a BS 110c may be a femto BS for a femto cell 102c. A BS may support one or multiple (e.g., three) cells. The terms “eNB” , “base station” , “NR BS” , “gNB” , “TRP” , “AP” , “node B” , “5G NB” , and “cell” may be used interchangeably herein.

In some aspects, a cell may not necessarily be stationary, and the geographic area of the cell may move according to the location of a mobile BS. In some aspects, the BSs may be interconnected to one another and/or to one or more other BSs or network nodes (not shown) in the wireless network 100 through various types of backhaul interfaces such as a direct physical connection, a virtual network, and/or the like using any suitable transport network.

Wireless network 100 may also include relay stations. A relay station is an entity that can receive a transmission of data from an upstream station (e.g., a BS or a UE) and send a transmission of the data to a downstream station (e.g., a UE or a BS) . A relay station may also be a UE that can relay transmissions for other UEs. In the example shown in Fig. 1, a relay BS 110d may communicate with macro BS 110a and a UE 120d in order to facilitate communication between BS 110a and UE 120d. A relay BS may also be referred to as a relay station, a relay base station, a relay, and/or the like.

Wireless network 100 may be a heterogeneous network that includes BSs of different types, e.g., macro BSs, pico BSs, femto BSs, relay BSs, and/or the like. These different types of BSs may have different transmit power levels, different coverage areas, and different impacts on interference in wireless network 100. For example, macro BSs may have a high transmit power level (e.g., 5 to 40 watts) whereas pico BSs, femto BSs, and relay BSs may have lower transmit power levels (e.g., 0.1 to 2 watts) .

A network controller 130 may couple to a set of BSs and may provide coordination and control for these BSs. Network controller 130 may communicate with the BSs via a backhaul. The BSs may also communicate with one another, e.g., directly or indirectly via a wireless or wireline backhaul.

UEs 120 (e.g., 120a, 120b, 120c) may be dispersed throughout wireless network 100, and each UE may be stationary or mobile. A UE may also be referred to as an access terminal, a terminal, a mobile station, a subscriber unit, a station, and/or the like. A UE may be a cellular phone (e.g., a smart phone) , a personal digital assistant (PDA) , a wireless modem, a wireless communication device, a handheld device, a laptop computer, a cordless phone, a wireless local loop (WLL) station, a tablet, a camera, a gaming device, a netbook, a smartbook, an ultrabook, a medical device or equipment, biometric sensors/devices, wearable devices (smart watches, smart clothing, smart glasses, smart wrist bands, smart jewelry (e.g., smart ring, smart bracelet) ) , an entertainment device (e.g., a music or video device, or a satellite radio) , a vehicular component or sensor, smart meters/sensors, industrial manufacturing equipment, a global positioning system device, or any other suitable device that is configured to communicate via a wireless or wired medium.

Some UEs may be considered machine-type communication (MTC) or evolved or enhanced machine-type communication (eMTC) UEs. MTC and eMTC UEs include, for example, robots, drones, remote devices, sensors, meters, monitors, location tags, and/or the like, that may communicate with a base station, another device (e.g., remote device) , or some other entity. A wireless node may provide, for example, connectivity for or to a network (e.g., a wide area network such as Internet or a cellular network) via a wired or wireless communication link. Some UEs may be considered Internet-of-Things (IoT) devices, and/or may be implemented as NB-IoT (narrowband internet of things) devices. Some UEs may be considered a Customer Premises Equipment (CPE) . UE 120 may be included inside a housing that houses components of UE 120, such as processor components, memory components, and/or the like. In some aspects, the processor components and the memory components may be coupled together. For example, the processor components (e.g., one or more processors) and the memory components (e.g., a memory) may be operatively coupled, communicatively coupled, electronically coupled, electrically coupled, and/or the like.

In general, any number of wireless networks may be deployed in a given geographic area. Each wireless network may support a particular RAT and may operate on one or more frequencies. A RAT may also be referred to as a radio technology, an air interface, and/or the like. A frequency may also be referred to as a carrier, a frequency channel, and/or the like. Each frequency may support a single RAT in a given geographic area in order to avoid interference between wireless networks of different RATs. In some cases, NR or 5G RAT networks may be deployed.

In some aspects, two or more UEs 120 (e.g., shown as UE 120a and UE 120e) may communicate directly using one or more sidelink channels (e.g., without using a base station 110 as an intermediary to communicate with one another) . For example, the UEs 120 may communicate using peer-to-peer (P2P) communications, device-to-device (D2D) communications, a vehicle-to-everything (V2X) protocol (e.g., which may include a vehicle-to-vehicle (V2V) protocol, a vehicle-to-infrastructure (V2I) protocol, and/or the like) , a mesh network, and/or the like. In this case, the UE 120 may perform scheduling operations, resource selection operations, and/or other operations described elsewhere herein as being performed by the base station 110.

Devices of wireless network 100 may communicate using the electromagnetic spectrum, which may be subdivided based on frequency or wavelength into various classes, bands, channels, and/or the like. For example, devices of wireless network 100 may communicate using an operating band having a first frequency range (FR1) , which may span from 410 MHz to 7.125 GHz, and/or may communicate using an operating band having a second frequency range (FR2) , which may span from 24.25 GHz to 52.6 GHz. The frequencies between FR1 and FR2 are sometimes referred to as mid-band frequencies. Although a portion of FR1 is greater than 6 GHz, FR1 is often referred to as a “sub-6 GHz” band. Similarly, FR2 is often referred to as a “millimeter wave” band despite being different from the extremely high frequency (EHF) band (30 GHz –300 GHz) which is identified by the International Telecommunications Union (ITU) as a “millimeter wave” band. Thus, unless specifically stated otherwise, it should be understood that the term “sub-6 GHz” or the like, if used herein, may broadly represent frequencies less than 6 GHz, frequencies within FR1, and/or mid-band frequencies (e.g., greater than 7.125 GHz) . Similarly, unless specifically stated otherwise, it should be understood that the term “millimeter wave” or the like, if used herein, may broadly represent frequencies within the EHF band, frequencies within FR2, and/or mid-band frequencies (e.g., less than 24.25 GHz) . It is contemplated that the frequencies included in FR1 and FR2 may be modified, and techniques described herein are applicable to those modified frequency ranges.

As indicated above, Fig. 1 is provided as an example. Other examples may differ from what is described with regard to Fig. 1.

Fig. 2 is a diagram illustrating an example 200 of a base station 110 in communication with a UE 120 in a wireless network 100, in accordance with various aspects of the present disclosure. Base station 110 may be equipped with T antennas 234a through 234t, and UE 120 may be equipped with R antennas 252a through 252r, where in general T ≥ 1 and R ≥ 1.

At base station 110, a transmit processor 220 may receive data from a data source 212 for one or more UEs, select one or more modulation and coding schemes (MCS) for each UE based at least in part on channel quality indicators (CQIs) received from the UE, process (e.g., encode and modulate) the data for each UE based at least in part on the MCS (s) selected for the UE, and provide data symbols for all UEs. Transmit processor 220 may also process system information (e.g., for semi-static resource partitioning information (SRPI) and/or the like) and control information (e.g., CQI requests, grants, upper layer signaling, and/or the like) and provide overhead symbols and control symbols. Transmit processor 220 may also generate reference symbols for reference signals (e.g., a cell-specific reference signal (CRS) , a demodulation reference signal (DMRS) , and/or the like) and synchronization signals (e.g., the primary synchronization signal (PSS) and secondary synchronization signal (SSS) ) . A transmit (TX) multiple-input multiple-output (MIMO) processor 230 may perform spatial processing (e.g., precoding) on the data symbols, the control symbols, the overhead symbols, and/or the reference symbols, if applicable, and may provide T output symbol streams to T modulators (MODs) 232a through 232t. Each modulator 232 may process a respective output symbol stream (e.g., for OFDM and/or the like) to obtain an output sample stream. Each modulator 232 may further process (e.g., convert to analog, amplify, filter, and upconvert) the output sample stream to obtain a downlink signal. T downlink signals from modulators 232a through 232t may be transmitted via T antennas 234a through 234t, respectively.

At UE 120, antennas 252a through 252r may receive the downlink signals from base station 110 and/or other base stations and may provide received signals to demodulators (DEMODs) 254a through 254r, respectively. Each demodulator 254 may condition (e.g., filter, amplify, downconvert, and digitize) a received signal to obtain input samples. Each demodulator 254 may further process the input samples (e.g., for OFDM and/or the like) to obtain received symbols. A MIMO detector 256 may obtain received symbols from all R demodulators 254a through 254r, perform MIMO detection on the received symbols if applicable, and provide detected symbols. A receive processor 258 may process (e.g., demodulate and decode) the detected symbols, provide decoded data for UE 120 to a data sink 260, and provide decoded control information and system information to a controller/processor 280. The term "controller/processor" may refer to one or more controllers, one or more processors, or a combination thereof. A channel processor may determine reference signal received power (RSRP) , received signal strength indicator (RSSI) , reference signal received quality (RSRQ) , channel quality indicator (CQI) , and/or the like. In some aspects, one or more components of UE 120 may be included in a housing 284.

Network controller 130 may include communication unit 294, controller/processor 290, and memory 292. Network controller 130 may include, for example, one or more devices in a core network. Network controller 130 may communicate with base station 110 via communication unit 294.

On the uplink, at UE 120, a transmit processor 264 may receive and process data from a data source 262 and control information (e.g., for reports that include RSRP, RSSI, RSRQ, CQI, and/or the like) from controller/processor 280. Transmit processor 264 may also generate reference symbols for one or more reference signals. The symbols from transmit processor 264 may be precoded by a TX MIMO processor 266 if applicable, further processed by modulators 254a through 254r (e.g., for DFT-s-OFDM, CP-OFDM, and/or the like) , and transmitted to base station 110. In some aspects, the UE 120 includes a transceiver. The transceiver may include any combination of antenna (s) 252, modulators and/or demodulators 254, MIMO detector 256, receive processor 258, transmit processor 264, and/or TX MIMO processor 266. The transceiver may be used by a processor (e.g., controller/processor 280) and memory 282 to perform aspects of any of the methods described herein, for example, as described with reference to Figs. 3-12.

At base station 110, the uplink signals from UE 120 and other UEs may be received by antennas 234, processed by demodulators 232, detected by a MIMO detector 236 if applicable, and further processed by a receive processor 238 to obtain decoded data and control information sent by UE 120. Receive processor 238 may provide the decoded data to a data sink 239 and the decoded control information to controller/processor 240. Base station 110 may include communication unit 244 and communicate to network controller 130 via communication unit 244. Base station 110 may include a scheduler 246 to schedule UEs 120 for downlink and/or uplink communications. In some aspects, the base station 110 includes a transceiver. The transceiver may include any combination of antenna (s) 234, modulators and/or demodulators 232, MIMO detector 236, receive processor 238, transmit processor 220, and/or TX MIMO processor 230. The transceiver may be used by a processor (e.g., controller/processor 240) and memory 242 to perform aspects of any of the methods described herein, for example, as described with reference to Figs. 3-12.

Controller/processor 240 of base station 110, controller/processor 280 of UE 120, and/or any other component (s) of Fig. 2 may perform one or more techniques associated with sidelink relay power allocation and precoder selection, as described in more detail elsewhere herein. For example, controller/processor 240 of base station 110, controller/processor 280 of UE 120, and/or any other component (s) of Fig. 2 may perform or direct operations of, for example, process 1200 of Fig. 12, and/or other processes as described herein.

Memories

242 and 282 may store data and program codes for base station 110 and UE 120, respectively. In some aspects, memory 242 and/or memory 282 may include a non-transitory computer-readable medium storing one or more instructions (e.g., code, program code, and/or the like) for wireless communication. For example, the one or more instructions, when executed (e.g., directly, or after compiling, converting, interpreting, and/or the like) by one or more processors of the base station 110 and/or the UE 120, may cause the one or more processors, the UE 120, and/or the base station 110 to perform or direct operations of, for example, process 1200 of Fig. 12, and/or other processes as described herein. In some aspects, executing instructions may include running the instructions, converting the instructions, compiling the instructions, interpreting the instructions, and/or the like.

In some aspects, UE 120 may include means for receiving a message at a first TRP controlled by UE 120, means for adjusting one or more of a power allocation or a precoder for one or more of the first TRP or a second TRP controlled by UE 120, means for relaying the message to another UE from one or more of the first TRP or the second TRP after adjusting the one or more of the power allocation or the precoder, and/or the like. In some aspects, such means may include one or more components of UE 120 described in connection with Fig. 2, such as controller/processor 280, transmit processor 264, TX MIMO processor 266, MOD 254, antenna 252, DEMOD 254, MIMO detector 256, receive processor 258, and/or the like.

While blocks in Fig. 2 are illustrated as distinct components, the functions described above with respect to the blocks may be implemented in a single hardware, software, or combination component or in various combinations of components. For example, the functions described with respect to the transmit processor 264, the receive processor 258, and/or the TX MIMO processor 266 may be performed by or under the control of controller/processor 280.

As indicated above, Fig. 2 is provided as an example. Other examples may differ from what is described with regard to Fig. 2.

Fig. 3 is a diagram illustrating an example 300 of sidelink communications, in accordance with various aspects of the present disclosure.

As shown in Fig. 3, a first UE 305-1 may communicate with a second UE 305-2 (and one or more other UEs 305) via one or more sidelink channels 310. The UEs 305-1 and 305-2 may communicate using the one or more sidelink channels 310 for P2P communications, D2D communications, V2X communications (e.g., which may include V2V communications, V2I communications, V2P communications, and/or the like) , mesh networking, and/or the like. In some aspects, the UEs 305 (e.g., UE 305-1 and/or UE 305-2) may correspond to one or more other UEs described elsewhere herein, such as UE 120. In some aspects, the one or more sidelink channels 310 may use a PC5 interface and/or may operate in a high frequency band (e.g., the 5.9 GHz band) . Additionally, or alternatively, the UEs 305 may synchronize timing of transmission time intervals (e.g., frames, subframes, slots, symbols, and/or the like) using global navigation satellite system timing.

As further shown in Fig. 3, the one or more sidelink channels 310 may include a physical sidelink control channel (PSCCH) 315, a physical sidelink shared channel (PSSCH) 320, and/or a physical sidelink feedback channel (PSFCH) 325. The PSCCH 315 may be used to communicate control information, similar to a physical downlink control channel (PDCCH) and/or a physical uplink control channel (PUCCH) used for cellular communications with a base station 110 via an access link or an access channel. The PSSCH 320 may be used to communicate data, similar to a physical downlink shared channel (PDSCH) and/or a physical uplink shared channel (PUSCH) used for cellular communications with base station 110 via an access link or an access channel. For example, the PSCCH 315 may carry sidelink control information (SCI) 330, which may indicate various control information used for sidelink communications, such as one or more resources (e.g., time resources, frequency resources, spatial resources, and/or the like) where a transport block (TB) 335 may be carried on the PSSCH 320. The TB 335 may include data. The PSFCH 325 may be used to communicate sidelink feedback 340, such as hybrid automatic repeat request (HARQ) feedback (e.g., acknowledgement or negative acknowledgement (ACK/NACK) information) , transmit power control, a scheduling request, and/or the like.

In some aspects, the one or more sidelink channels 310 may use resource pools. For example, a scheduling assignment (e.g., included in SCI 330) may be transmitted in sub-channels using specific resource blocks (RBs) across time. In some aspects, data transmissions (e.g., on the PSSCH 320) associated with a scheduling assignment may occupy adjacent RBs in the same subframe as the scheduling assignment (e.g., using frequency division multiplexing) . In some aspects, a scheduling assignment and associated data transmissions are not transmitted on adjacent RBs.

In some aspects, a UE 305 may operate using a transmission mode where resource selection and/or scheduling is performed by the UE 305 (e.g., rather than a base station 110) . In some aspects, the UE 305 may perform resource selection and/or scheduling by sensing channel availability for transmissions. For example, the UE 305 may measure a received signal strength indicator (RSSI) parameter (e.g., a sidelink- RSSI (S-RSSI) parameter) associated with various sidelink channels, may measure a reference signal received power (RSRP) parameter (e.g., a PSSCH-RSRP parameter) associated with various sidelink channels, may measure a reference signal received quality (RSRQ) parameter (e.g., a PSSCH-RSRQ parameter) associated with various sidelink channels, and/or the like, and may select a channel for transmission of a sidelink communication based at least in part on the measurement (s) .

Additionally, or alternatively, the UE 305 may perform resource selection and/or scheduling using SCI 330 received in the PSCCH 315, which may indicate occupied resources, channel parameters, and/or the like. Additionally, or alternatively, the UE 305 may perform resource selection and/or scheduling by determining a channel busy rate associated with various sidelink channels, which may be used for rate control (e.g., by indicating a maximum number of resource blocks that the UE 305 can use for a particular set of subframes) .

In the transmission mode where resource selection and/or scheduling is performed by a UE 305, the UE 305 may generate sidelink grants, and may transmit the grants in SCI 330. A sidelink grant may indicate, for example, one or more parameters (e.g., transmission parameters) to be used for an upcoming sidelink transmission, such as one or more resource blocks to be used for the upcoming sidelink transmission on the PSSCH 320 (e.g., for TBs 335) , one or more subframes to be used for the upcoming sidelink transmission, a modulation and coding scheme to be used for the upcoming sidelink transmission, and/or the like. In some aspects, a UE 305 may generate a sidelink grant that indicates one or more parameters for semi-persistent scheduling, such as a periodicity of a sidelink transmission. Additionally, or alternatively, the UE 305 may generate a sidelink grant for event-driven scheduling, such as for an on-demand sidelink message.

As indicated above, Fig. 3 is provided as an example. Other examples may differ from what is described with respect to Fig. 3.

Fig. 4 is a diagram illustrating an example 400 of sidelink communications and access link communications, in accordance with various aspects of the present disclosure.

As shown in Fig. 4, a UE 405 and another UE 410 may communicate with one another via a sidelink, as described above in connection with Fig. 3. As further shown, in some sidelink modes, a base station 110 may communicate with Tx UE 405 via a first access link. Additionally, or alternatively, in some sidelink modes, base station 110 may communicate with the Rx UE 410 via a second access link. The Tx UE 405 and/or the Rx UE 410 may correspond to one or more UEs described elsewhere herein, such as the UE 120 of Fig. 1. Thus, a direct link between UEs 120 (e.g., via a PC5 interface) may be referred to as a sidelink, and a direct link between a base station 110 and a UE 120 (e.g., via a Uu interface) may be referred to as an access link. Sidelink communications may be transmitted via the sidelink, and access link communications may be transmitted via the access link. An access link communication may be either a downlink communication (from a base station 110 to a UE 120) or an uplink communication (from a UE 120 to a base station 110) .

As indicated above, Fig. 4 is provided as an example. Other examples may differ from what is described with respect to Fig. 4.

Fig. 5 is a diagram illustrating an example 500 of sidelink relaying, in accordance with various aspects of the present disclosure.

There are different types of relays. For example, there is network-to-UE relay, where a relay UE is connected to a serving base station so that more remote UEs can receive data from or transmit data to the network through the relay UE. This may be beneficial to remote UEs at a cell edge. There is also UE-to-UE relay, where relay UE traffic is relayed from a source UE to a remote UE via sidelink (PC5) communications. Fig. 5 shows an example of a UE-to-UE relay. A source UE may transmit data to a relay UE, which relays the data to a remote UE.

As indicated above, Fig. 5 is provided as an example. Other examples may differ from what is described with respect to Fig. 5.

Fig. 6 is a diagram illustrating an example 600 of sidelink resources, in accordance with various aspects of the present disclosure.

V2X communications may use periodic and aperiodic transmissions. Fig. 6 shows an example 600 of resource reservations for aperiodic transmissions. A UE may reserve resources in a current slot and in up to two future slots. The UE may allocate resources in sub-channels in the frequency domain and in one slot in the time domain. Reservation information may be carried in SCI. The UE may exclude or select resource reservation candidates based on an RSRP measurement result of a PSCCH or a PSSCH within a pre-defined sensing window.

As indicated above, Fig. 6 is provided as an example. Other examples may differ from what is described with respect to Fig. 6.

Fig. 7 is a diagram illustrating an example 700 of a vehicle with multiple TRPs, in accordance with various aspects of the present disclosure.

Coverage for V2X communications may be enhanced with multiple TRPs. Multiple TRPs may improve reliability, coverage, and capacity performance through flexible deployment scenarios. More specifically, multiple TRPs equipped in different portions of a vehicle may improve reliability in safety applications or other robust applications. For example, as shown in Fig. 7, a vehicle may have a TRP at a front end (TRP1) and a TRP at a rear end (TRP2) .

Transmission coverage for the multiple TRPs may vary depending on what application is used for the vehicle. For example, side coverage for a vehicle may not be as important as front or back coverage for collision avoidance applications. From a receiver point of view, multiple TRPs on a vehicle may be desirable for 360 degree coverage. For example, it may be better to use TRPs on both ends of a vehicle to receive packets from other UEs. However, some messages received by a first TRP on the vehicle may not be successfully relayed to another UE from a second TRP on the vehicle, which may result in a safety feature not operating as designed. There may be other inefficiencies in how the TRPs on a vehicle transmit and receive sidelink communications. These inefficiencies may degrade communications and cause the UE to waste signaling resources by resending communications.

As indicated above, Fig. 7 is provided as an example. Other examples may differ from what is described with respect to Fig. 7.

According to various aspects described herein, a UE controlling multiple TRPs on a vehicle may adjust a power allocation or precoder for one or more of the multiple TRPs. In this way, the UE may improve sidelink communications with other UEs.

Fig. 8 is a diagram illustrating an example 800 of sidelink relaying with multiple TRPs, in accordance with various aspects of the present disclosure. Fig. 8 shows sidelink communications involving a source UE in a leading vehicle, a relay UE in a middle vehicle, and a remote UE in a trailing vehicle.

As shown by reference number 805, the relay UE may receive a message at TRP1 from the source UE. The message may indicate that the source UE is stopping at a traffic light. The message may be received at TRP1 with a higher RSRP than at TRP2. For example, an RSRP measurement of TRP1 may be much larger than an RSRP measurement for TRP2 (e.g., RSRP_1 > RSRP_2 + X decibels) , where X may be greater than a threshold. In other words, RSRP_1 may be much greater than RSRP_2. The relay UE may determine a direction of the message based at least in part on receiving the message at TRP1 with a higher RSRP than at TRP2. The direction may be toward vehicles behind the source UE. The relay UE may determine to relay the message to the remote UE in the trailing vehicle.

In some aspects, the relay UE of the middle vehicle may adjust a power allocation of TRP2 in order to strengthen a power of transmission to the remote UE, as shown by reference number 810. This may include directing almost all power to TRP2. In some aspects, if beam sweeping is enabled at the relay UE, candidate beams may be limited to pre-selected directional beams. Directional beams may be indicated by certain precoders, and the relay UE may select such a precoder.

As shown by reference number 815, the relay UE may relay the message to the remote UE with the adjusted power allocation or precoder. The message may be relayed in its original form or may be modified or recreated by the relay UE.

As indicated above, Fig. 8 is provided as an example. Other examples may differ from what is described with respect to Fig. 8.

Fig. 9 is a diagram illustrating an example 900 of sidelink relaying with multiple TRPs, in accordance with various aspects of the present disclosure. Fig. 9 shows a remote vehicle in a first geographical zone, a relay vehicle in a second geographical zone, and a source vehicle in a third geographical zone.

In some aspects, a relay UE in the relay vehicle may adjust a power allocation or precoder for one or more TRPs based at least in part on a location of another vehicle, such as the remote vehicle. For example, the relay UE may receive a message from a source UE in the source vehicle. The message may include SCI. The relay UE may decode the SCI to obtain a zone identifier (ID) indicating the zone in which the source vehicle resides. The relay UE may use this zone to determine a location of the source vehicle and a direction for the message, given a current zone (location) of the relay vehicle.

The relay UE may increase a transmission power of a TRP that will relay the message in the direction for the message and/or select a precoder with a beam in the direction for the message. In some aspects, if beamforming management is activated, beam sweep selection may also take the location information into consideration, so as to reduce beam sweeping resources. In this way, a remote UE in the remote vehicle may have a better chance of receiving the relayed message. In some aspects, the relay UE may determine a zone of the remote vehicle and increase a transmission power for a TRP that will relay the message towards the zone of the remote vehicle.

As indicated above, Fig. 9 is provided as an example. Other examples may differ from what is described with respect to Fig. 9.

Fig. 10 is a diagram illustrating an example 1000 of sidelink relaying with multiple TRPs, in accordance with various aspects of the present disclosure. Fig. 10 shows sidelink communications involving a source UE in a leading vehicle, a relay UE in a middle vehicle, and a remote UE in a trailing vehicle.

In some aspects, the relay UE may adjust a power allocation or precoder for one or more TRPs based at least in part on an application type or a traffic type associated with the message. For example, in Fig. 10, the relay UE may be aware that the message to be relayed is for a rear biased application that warns trailing vehicles (e.g., collision warning messages) . Therefore, the relay UE may allocate more transmission power to a rear TRP (TRP2) for better reception performance. The application type may be indicated in an application layer, and information about the application may be provided to lower layers of the relay UE.

In some aspects, the relay UE may allocate more power to a TRP or select a different precoder for a relay message based at least on a traffic type. For example, traffic may be highway traffic and thus power may need to be increased to relay messages at a greater distance.

As indicated above, Fig. 10 is provided as an example. Other examples may differ from what is described with respect to Fig. 10.

Fig. 11 is a diagram illustrating an example 1100 of sidelink relaying with multiple TRPs, in accordance with various aspects of the present disclosure. Fig. 11 shows sidelink communications involving a source UE in a leading vehicle and a relay UE in a trailing vehicle.

TRP adjustments may not be limited to a rear end TRP. In some aspects, the relay UE may adjust a power allocation or precoder for a TRP in a front end of the relay vehicle based at least in part on an application type. For example, in Fig. 11, the relay UE may allocate more power to a front end TRP because the relay UE is providing an overtaking vehicle warning to the leading vehicle.

As indicated above, Fig. 11 is provided as an example. Other examples may differ from what is described with respect to Fig. 11.

Fig. 12 is a diagram illustrating an example process 1200 performed, for example, by a UE, in accordance with various aspects of the present disclosure. Example process 1200 is an example where the UE (e.g., a UE 120 depicted in Figs. 1 and 2, the relay UE depicted in Figs. 8 and 10, and/or the like) performs operations associated with sidelink relay power allocation and precoder selection.

As shown in Fig. 12, in some aspects, process 1200 may include receiving a message at a first TRP controlled by the UE (block 1210) . For example, the UE (e.g., using receive processor 258, transmit processor 264, controller/processor 280, memory 282, and/or the like) may receive a message at a first TRP controlled by the UE, as described above.

As further shown in Fig. 12, in some aspects, process 1200 may include adjusting one or more of a power allocation or a precoder for one or more of the first TRP or a second TRP controlled by the UE (block 1220) . For example, the UE (e.g., using receive processor 258, transmit processor 264, controller/processor 280, memory 282, and/or the like) may adjust one or more of a power allocation or a precoder for one or more of the first TRP or a second TRP controlled by the UE, as described above.

As further shown in Fig. 12, in some aspects, process 1200 may include relaying the message to another UE from one or more of the first TRP or the second TRP after adjusting the one or more of the power allocation or the precoder (block 1230) . For example, the UE (e.g., using receive processor 258, transmit processor 264, controller/processor 280, memory 282, and/or the like) may relay the message to another UE from one or more of the first TRP or the second TRP after adjusting the one or more of the power allocation or the precoder, as described above.

Process 1200 may include additional aspects, such as any single aspect or any combination of aspects described below and/or in connection with one or more other processes described elsewhere herein.

In a first aspect, the first TRP is at a first portion of a vehicle housing the UE, and the second TRP is at a second portion of the vehicle.

In a second aspect, alone or in combination with the first aspect, the first TRP is at a first end of a vehicle housing the UE and the second TRP is at a second end of the vehicle, adjusting one or more of the power allocation or the precoder includes adjusting one or more of the power allocation or the precoder for the second TRP, and relaying the message to the other UE includes relaying the message to the other UE from the second TRP.

In a third aspect, alone or in combination with one or more of the first and second aspects, adjusting one or more of the power allocation or the precoder includes increasing a transmission power of the second TRP based at least in part on one or more measurement results at the first TRP.

In a fourth aspect, alone or in combination with one or more of the first through third aspects, increasing the transmission power of the second TRP includes increasing the transmission power of the second TRP based at least in part on determining a direction for relaying the message.

In a fifth aspect, alone or in combination with one or more of the first through fourth aspects, adjusting one or more of the power allocation or the precoder includes selecting, for the second TRP, a precoder with a beam in a direction for relaying the message.

In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, adjusting one or more of the power allocation or the precoder includes adjusting one or more of the power allocation or the precoder for one or more of the first TRP or the second TRP based at least in part on a location of one or more of the other UE or a UE transmitting the message.

In a seventh aspect, alone or in combination with one or more of the first through sixth aspects, the location is indicated by a zone identifier that is decoded from sidelink control information.

In an eighth aspect, alone or in combination with one or more of the first through seventh aspects, adjusting one or more of the power allocation or the precoder includes adjusting one or more of the power allocation or the precoder for one or more of the first TRP or the second TRP based at least in part on an application type associated with the message.

In a ninth aspect, alone or in combination with one or more of the first through eighth aspects, adjusting one or more of the power allocation or the precoder includes adjusting one or more of the power allocation or the precoder for one or more of the first TRP or the second TRP based at least in part on a traffic type associated with the message.

Although Fig. 12 shows example blocks of process 1200, in some aspects, process 1200 may include additional blocks, fewer blocks, different blocks, or differently arranged blocks than those depicted in Fig. 12. Additionally, or alternatively, two or more of the blocks of process 1200 may be performed in parallel.

The foregoing disclosure provides illustration and description, but is not intended to be exhaustive or to limit the aspects to the precise form disclosed. Modifications and variations may be made in light of the above disclosure or may be acquired from practice of the aspects.

As used herein, the term “component” is intended to be broadly construed as hardware, firmware, and/or a combination of hardware and software. As used herein, a processor is implemented in hardware, firmware, and/or a combination of hardware and software. It will be apparent that systems and/or methods described herein may be implemented in different forms of hardware, firmware, and/or a combination of hardware and software. The actual specialized control hardware or software code used to implement these systems and/or methods is not limiting of the aspects. Thus, the operation and behavior of the systems and/or methods were described herein without reference to specific software code-it being understood that software and hardware can be designed to implement the systems and/or methods based, at least in part, on the description herein.

As used herein, satisfying a threshold may, depending on the context, refer to a value being greater than the threshold, greater than or equal to the threshold, less than the threshold, less than or equal to the threshold, equal to the threshold, not equal to the threshold, and/or the like.

Even though particular combinations of features are recited in the claims and/or disclosed in the specification, these combinations are not intended to limit the disclosure of various aspects. In fact, many of these features may be combined in ways not specifically recited in the claims and/or disclosed in the specification. Although each dependent claim listed below may directly depend on only one claim, the disclosure of various aspects includes each dependent claim in combination with every other claim in the claim set. A phrase referring to “at least one of” a list of items refers to any combination of those items, including single members. As an example, “at least one of: a, b, or c” is intended to cover a, b, c, a-b, a-c, b-c, and a-b-c, as well as any combination with multiples of the same element (e.g., a-a, a-a-a, a-a-b, a-a-c, a-b-b, a-c-c, b-b, b-b-b, b-b-c, c-c, and c-c-c or any other ordering of a, b, and c) .

No element, act, or instruction used herein should be construed as critical or essential unless explicitly described as such. Also, as used herein, the articles “a” and “an” are intended to include one or more items and may be used interchangeably with “one or more. ” Further, as used herein, the article “the” is intended to include one or more items referenced in connection with the article “the” and may be used interchangeably with “the one or more. ” Furthermore, as used herein, the terms “set” and “group” are intended to include one or more items (e.g., related items, unrelated items, a combination of related and unrelated items, and/or the like) , and may be used interchangeably with “one or more. ” Where only one item is intended, the phrase “only one” or similar language is used. Also, as used herein, the terms “has, ” “have, ” “having, ” and/or the like are intended to be open-ended terms. Further, the phrase “based on” is intended to mean “based, at least in part, on” unless explicitly stated otherwise. Also, as used herein, the term “or” is intended to be inclusive when used in a series and may be used interchangeably with “and/or, ” unless explicitly stated otherwise (e.g., if used in combination with “either” or “only one of” ) .

Claims

A method of wireless communication performed by a user equipment (UE) , comprising:

receiving a message at a first transmission reception point (TRP) controlled by the UE;

adjusting one or more of a power allocation or a precoder for one or more of the first TRP or a second TRP controlled by the UE; and

relaying the message to another UE from one or more of the first TRP or the second TRP after adjusting the one or more of the power allocation or the precoder.
The method of claim 1, wherein the first TRP is at a first portion of a vehicle housing the UE, and the second TRP is at a second portion of the vehicle.
The method of claim 1, wherein the first TRP is at a first end of a vehicle housing the UE, and the second TRP is at a second end of the vehicle, wherein adjusting one or more of the power allocation or the precoder includes adjusting one or more of the power allocation or the precoder for the second TRP, and wherein relaying the message to the other UE includes relaying the message to the other UE from the second TRP.
The method of claim 1, wherein adjusting one or more of the power allocation or the precoder includes increasing a transmission power of the second TRP based at least in part on one or more measurement results at the first TRP.
The method of claim 4, wherein increasing the transmission power of the second TRP includes increasing the transmission power of the second TRP based at least in part on determining a direction for relaying the message.
The method of claim 1, wherein adjusting one or more of the power allocation or the precoder includes selecting, for the second TRP, a precoder with a beam in a direction for relaying the message.
The method of claim 1, wherein adjusting one or more of the power allocation or the precoder includes adjusting one or more of the power allocation or the precoder for one or more of the first TRP or the second TRP based at least in part on a location of one or more of the other UE or a UE transmitting the message.
The method of claim 7, wherein the location is indicated by a zone identifier that is decoded from sidelink control information.
The method of claim 1, wherein adjusting one or more of the power allocation or the precoder includes adjusting one or more of the power allocation or the precoder for one or more of the first TRP or the second TRP based at least in part on an application type associated with the message.
The method of claim 1, wherein adjusting one or more of the power allocation or the precoder includes adjusting one or more of the power allocation or the precoder for one or more of the first TRP or the second TRP based at least in part on a traffic type associated with the message.
A user equipment (UE) for wireless communication, comprising:

a memory; and

one or more processors operatively coupled to the memory, the memory and the one or more processors configured to:

receive a message at a first transmission reception point (TRP) controlled by the UE;

adjust one or more of a power allocation or a precoder for one or more of the first TRP or a second TRP controlled by the UE; and

relay the message to another UE from one or more of the first TRP or the second TRP after adjusting the one or more of the power allocation or the precoder.
A non-transitory computer-readable medium storing a set of instructions for

wireless communication, the set of instructions comprising:

one or more instructions that, when executed by one or more processors of a user equipment (UE) , cause the UE to:

receive a message at a first transmission reception point (TRP) controlled by the UE;

adjust one or more of a power allocation or a precoder for one or more of the first TRP or a second TRP controlled by the UE; and

relay the message to another UE from one or more of the first TRP or the second TRP after adjusting the one or more of the power allocation or the precoder.
An apparatus for wireless communication, comprising:

means for receiving a message at a first transmission reception point (TRP) controlled by the apparatus;

means for adjusting one or more of a power allocation or a precoder for one or more of the first TRP or a second TRP controlled by the apparatus; and

means for relaying the message to another apparatus from one or more of the first TRP or the second TRP after adjusting the one or more of the power allocation or the precoder.