Patent ID: 12250080

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 3G and/or 4G wireless technologies, aspects of the present disclosure can be applied in other generation-based communication systems, such as 5G and later, including NR technologies.

FIG.1is a diagram illustrating a wireless network100in which aspects of the present disclosure may be practiced. The wireless network100may be an LTE network or some other wireless network, such as a 5G or NR network. The wireless network100may include a number of BSs110(shown as BS110a, BS110b, BS110c, and BS110d) and other network entities. A BS is an entity that communicates with user equipment (UEs) and may also be referred to as a base station, a 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 inFIG.1, a BS110amay be a macro BS for a macro cell102a, a BS110bmay be a pico BS for a pico cell102b, and a BS110cmay be a femto BS for a femto cell102c. 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 network100through various types of backhaul interfaces such as a direct physical connection, a virtual network, and/or the like using any suitable transport network.

Wireless network100may 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 inFIG.1, a relay station110dmay communicate with macro BS110aand a UE120din order to facilitate communication between BS110aand UE120d. A relay station may also be referred to as a relay BS, a relay base station, a relay, and/or the like.

Wireless network100may 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 network100. 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 controller130may couple to a set of BSs and may provide coordination and control for these BSs. Network controller130may 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.

UEs120(e.g.,120a,120b,120c) may be dispersed throughout wireless network100, 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). UE120may be included inside a housing that houses components of UE120, such as processor components, memory components, 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 radio access technology (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 UEs120(e.g., shown as UE120aand UE120e) may communicate directly using one or more sidelink channels (e.g., without using a base station110as an intermediary to communicate with one another). For example, the UEs120may 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 UE120may perform scheduling operations, resource selection operations, and/or other operations described elsewhere herein as being performed by the base station110.

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

FIG.2shows a diagram of a design200of base station110and UE120, which may be one of the base stations and one of the UEs inFIG.1. Base station110may be equipped with T antennas234athrough234t, and UE120may be equipped with R antennas252athrough252r, where in general T≥1 and R≥1.

At base station110, a transmit processor220may receive data from a data source212for 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 processor220may 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 processor220may also generate reference symbols for reference signals (e.g., the cell-specific reference signal (CRS)) and synchronization signals (e.g., the primary synchronization signal (PSS) and secondary synchronization signal (SSS)). A transmit (TX) multiple-input multiple-output (MIMO) processor230may 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)232athrough232t. Each modulator232may process a respective output symbol stream (e.g., for OFDM and/or the like) to obtain an output sample stream. Each modulator232may further process (e.g., convert to analog, amplify, filter, and upconvert) the output sample stream to obtain a downlink signal. T downlink signals from modulators232athrough232tmay be transmitted via T antennas234athrough234t, respectively. According to various aspects described in more detail below, the synchronization signals can be generated with location encoding to convey additional information.

At UE120, antennas252athrough252rmay receive the downlink signals from base station110and/or other base stations and may provide received signals to demodulators (DEMODs)254athrough254r, respectively. Each demodulator254may condition (e.g., filter, amplify, downconvert, and digitize) a received signal to obtain input samples. Each demodulator254may further process the input samples (e.g., for OFDM and/or the like) to obtain received symbols. A MIMO detector256may obtain received symbols from all R demodulators254athrough254r, perform MIMO detection on the received symbols if applicable, and provide detected symbols. A receive processor258may process (e.g., demodulate and decode) the detected symbols, provide decoded data for UE120to a data sink260, and provide decoded control information and system information to a controller/processor280. 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 UE120may be included in a housing.

On the uplink, at UE120, a transmit processor264may receive and process data from a data source262and control information (e.g., for reports comprising RSRP, RSSI, RSRQ, CQI, and/or the like) from controller/processor280. Transmit processor264may also generate reference symbols for one or more reference signals. The symbols from transmit processor264may be precoded by a TX MIMO processor266if applicable, further processed by modulators254athrough254r(e.g., for DFT-s-OFDM, CP-OFDM, and/or the like), and transmitted to base station110. At base station110, the uplink signals from UE120and other UEs may be received by antennas234, processed by demodulators232, detected by a MIMO detector236if applicable, and further processed by a receive processor238to obtain decoded data and control information sent by UE120. Receive processor238may provide the decoded data to a data sink239and the decoded control information to controller/processor240. Base station110may include communication unit244and communicate to network controller130via communication unit244. Network controller130may include communication unit294, controller/processor290, and memory292.

Controller/processor240of base station110, controller/processor280of UE120, and/or any other component(s) ofFIG.2may perform one or more techniques associated with communication via sidelink relay, as described in more detail elsewhere herein. For example, controller/processor240of base station110, controller/processor280of UE120, and/or any other component(s) ofFIG.2may perform or direct operations of, for example, process700ofFIG.7, process800ofFIG.8, process900ofFIG.9, and/or other processes as described herein. Memories242and282may store data and program codes for base station110and UE120, respectively. In some aspects, memory242and/or memory282may comprise a non-transitory computer-readable medium storing one or more instructions for wireless communication. For example, the one or more instructions, when executed by one or more processors of the base station110and/or the UE120, may perform or direct operations of, for example, process700ofFIG.7, process800ofFIG.8, process900ofFIG.9, and/or other processes as described herein. A scheduler246may schedule UEs for data transmission on the downlink and/or uplink.

In some aspects, UE120may include means for determining that one or more communications with a base station are to be transmitted or received via a relay UE, where the one or more communications include at least one of hybrid automatic repeat request (HARQ) feedback, a retransmission, or a control communication, means for transmitting or receiving the one or more communications via the relay UE, means for determining that one or more communications between a base station and a UE are to be transmitted or received via the UE120, where the one or more communications include at least one of HARQ feedback, a retransmission, or a control communication, means for relaying the one or more communications between the base station and the UE, and/or the like. In some aspects, such means may include one or more components of UE120described in connection withFIG.2, such as controller/processor280, transmit processor264, TX MIMO processor266, MOD254, antenna252, DEMOD254, MIMO detector256, receive processor258, and/or the like.

In some aspects, base station110may include means for determining that one or more communications with a UE are to be transmitted or received via a relay UE, where the one or more communications include at least one of HARQ feedback, a retransmission, or a control communication, means for transmitting or receiving the one or more communications via the relay UE, and/or the like. In some aspects, such means may include one or more components of base station110described in connection withFIG.2, such as antenna234, DEMOD232, MIMO detector236, receive processor238, controller/processor240, transmit processor220, TX MIMO processor230, MOD232, antenna234, and/or the like.

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

FIG.3is a diagram illustrating an example300of communications via a sidelink, in accordance with certain aspects of the present disclosure.

As shown inFIG.3, a first UE305-1may communicate with a second UE305-2(and one or more other UEs305) using device-to-device (D2D) communications via one or more sidelink channels310. In some aspects, the UEs305may correspond to one or more other UEs described elsewhere herein, such as UE120and/or the like. In some aspects, the sidelink channel310may use a PC5 interface and/or may operate in a high frequency band (e.g., the 5.9 GHz band). Additionally, or alternatively, the UEs305may synchronize timing of transmission time intervals (e.g., frames, subframes, slots, and/or the like) using global navigation satellite system (GNSS) timing. The UEs305may transmit communications (e.g., one-to-many broadcasts and/or multicast transmissions) using the sidelink channel310.

As further shown inFIG.3, the sidelink channel310may include a physical sidelink control channel (PSCCH)315and a physical sidelink shared channel (PSSCH)320. The PSCCH315may be used to communicate control information, similar to a physical downlink control channel (PDCCH) and/or a physical uplink control channel (PUCCH) used for communications with a base station110. The PSSCH320may be used to communicate data, similar to a physical downlink shared channel (PDSCH) and/or a physical uplink shared channel (PUSCH) used for communications with a base station110. For example, the PSCCH315may carry sidelink control information (SCI)325, which may indicate various control information used for sidelink communications, such as one or more resources (e.g., time and/or frequency resources) where a transport block (TB)330that includes data is carried on the PSSCH320. In some cases, the TB330may include vehicle-to-everything (V2X) data, such as a basic safety message (BSM), a traffic information message (TIM), a signal phase and time (SPAT) message, a MAP message to convey geographic road information, a cooperative awareness message (CAM), a distributed environment notification message (DENM), an in-vehicle information (IVI) message, and/or the like.

In some aspects, the sidelink channel310may use resource pools. For example, a scheduling assignment (e.g., included in SCI325) may be transmitted in sub-channels using specific resource blocks (RBs) across time. In some aspects, data transmissions (e.g., on the PSSCH320) 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 UE305may operate using transmission mode3, where resource selection and/or scheduling is performed by a base station110. In some aspects, a UE305may operate using transmission mode4, where resource selection and/or scheduling is performed by the UE305(e.g., rather than a base station110). In some aspects, the UE305may perform resource selection and/or scheduling by sensing channel availability for transmissions. For example, the UE305may 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 communications based at least in part on the measurement(s).

Additionally, or alternatively, the UE305may perform resource selection and/or scheduling using SCI325received in the PSCCH315, which may indicate occupied resources, channel parameters, and/or the like. Additionally, or alternatively, the UE305may perform resource selection and/or scheduling by determining a channel busy rate (CBR) associated with various sidelink channels, which may be used for rate control (e.g., by indicating a maximum number of resource blocks that the UE305can use for a particular set of subframes).

In transmission mode4, a UE305may generate sidelink grants, and may transmit the grants in SCI325. A sidelink grant may indicate, for example, one or more parameters (e.g., transmission parameters) to be used for an upcoming transmission, such as one or more resource blocks to be used for the upcoming transmission on the PSSCH320(e.g., for TBs330), one or more subframes to be used for the upcoming transmission, a modulation and coding scheme (MCS) to be used for the upcoming transmission, and/or the like. In some aspects, a UE305may generate a sidelink grant that indicates one or more parameters for semi-persistent scheduling (SPS), such as a periodicity of a transmission (e.g., a periodic V2X message, such as a safety message and/or the like). Additionally, or alternatively, the UE305may generate a sidelink grant for event-driven scheduling, such as for an on-demand message.

A UE305in coverage of a base station110may perform sidelink communication using a configuration and control information provided dynamically by the base station110, and according to one or more configured parameters. A UE305that is out of coverage of a base station110may autonomously perform sidelink communication according to configured parameters. A UE305that is out of coverage may receive system information from another UE305that is in coverage.

In some wireless communication systems, the first UE305-1may have dual connectivity with a base station110on an access link325-1and with the second UE305-2on a sidelink310. However, in some cases, the access link325-1may have a poor channel quality, for example, when the first UE305-1is located near a cell edge, when the first UE305-1is associated with a low tier, and/or the like. As a result of the poor channel quality, communication between the first UE305-1and the BS110may include multiple HARQ feedback transmissions and/or multiple retransmissions, thereby causing delays, consuming additional network and UE resources, and/or the like. For example, if a downlink transmission from the BS110fails at the first UE305-1, the UE may signal negative acknowledgment feedback to the BS110. The BS110may retransmit the failed communication using a different redundancy version. Here, each redundancy version used for a transmission may correspond to a different set of parity bits of the same encoded block (e.g., the variation between the different sets of bits is controlled by the redundancy version that is used). The first UE305-1may continue to negatively acknowledgment retransmissions, and the BS110may perform further retransmissions until the communication is successful or a retransmission limit is reached.

Some techniques and apparatuses described herein utilize the sidelink with the second UE305-2(e.g., a relay UE) for relaying communications, such as HARQ feedback and/or retransmissions, between the first UE305-1(e.g., a target UE) and the BS110. For example, the second UE305-2may receive downlink communications from the BS110on an access link325-2, and relay the downlink communications to the first UE305-1on the sidelink310. Similarly, the second UE305-2may receive uplink communications from the first UE305-1, and relay the uplink communications to the BS110on the access link325-2. In this way, performance of the communications is improved, which may reduce delays, reduce HARQ feedback transmissions and retransmissions, conserve network and UE resources, and/or the like.

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

FIGS.4-6are diagrams illustrating examples400,500, and600, respectively, of communication via sidelink relay, in accordance with various aspects of the present disclosure. As shown inFIGS.4-6, a target UE305(e.g., one of the first UE305-1or the second UE305-2) may communicate with a relay UE305(e.g., the other of the first UE305-1or the second UE305-2) and a BS110. For example, the target UE305may have a dual connectivity to the relay UE305and the BS110, and the relay UE305may have a dual connectivity to the target UE305and the BS110. In some aspects, the target UE305may communicate with the relay UE305on a sidelink (e.g., sidelink310), the target UE305may communicate with the BS110on a first access link (e.g., access link325-1), such as over a Uu interface, and the relay UE305may communicate with the BS110on a second access link (e.g., access link325-2), such as over a second Uu interface.

In such cases, the target UE305and the BS110may use the relay UE305as a relay for communications between the target UE305and the BS110. In some aspects, the target UE305and the BS110may use the relay UE305as the relay when the target UE305is within a coverage of the relay UE305. For example, the target UE305, the relay UE305, and/or the BS110may determine that the relay UE305is to be used as the relay in connection with a determination that the target UE305is within the coverage of the relay UE305.

In some aspects, the target UE305and/or the relay UE305may transmit an indication to the BS110that the relay UE305is to be used as the relay. In some aspects, the target UE305and/or the relay UE305may receive an indication from the BS110that the relay UE305is to be used as the relay. An indication may be transmitted or received via radio resource control (RRC) signaling, a medium access control control element (MAC-CE), or downlink control information (DCI). In some aspects, an indication may be based at least in part on whether the target UE305is a low-tier UE and the relay UE305is a high-tier UE. A high-tier UE may refer to a UE that is associated with a receive bandwidth capability in receiving downlink signals/channels that is above a particular threshold (e.g., a bandwidth of greater than or equal to 100 megahertz (MHz)). In contrast, a low-tier UE (e.g., an NR-light UE, a low-capability UE, and/or the like) may refer to a UE with a bandwidth capability in receiving the downlink signals/channels that is below a particular threshold (e.g., a bandwidth of less than 10 MHz, less than 5 MHz, and/or the like). Low-tier UEs may include wearable devices, Internet of Things (IoT) devices, sensors, cameras, and/or the like that are associated with a limited bandwidth, power capacity, transmission range, and/or the like.

In some aspects, an indication may be based at least in part on whether the target UE305is associated with a lower capability than the relay UE305. For example, the target UE305may have a lower processing capability than the relay UE305. In some aspects, an indication may be based at least in part on whether the first access link of the target UE305with the BS110has a lesser quality than the second access link of the relay UE305with the BS110(e.g., in connection with reference signal received quality (RSRQ) measurements, and/or the like, on the first access link and the second access link). In some aspects, an indication may be based at least in part on whether the target UE305is located further from the BS110than the relay UE305.

In some aspects, an indication may be based at least in part on a capability report transmitted by the target UE305and/or the relay UE305. In some aspects, the target UE305may transmit, to the BS110and/or the relay UE305, a capability report that indicates whether the target UE305supports using a relay UE for one or more of relaying an initial transmission, relaying HARQ feedback, relaying a retransmission, relaying a data channel communication, or relaying a control channel communication. In some aspects, the relay UE305may transmit, to the BS110and/or the target UE305, a capability report that indicates whether the relay UE305supports one or more of relaying an initial transmission, relaying HARQ feedback, relaying a retransmission, relaying a data channel communication, or relaying a control channel communication.

In some aspects, the target UE305may determine (e.g., based at least in part on receiving or transmitting an indication) that one or more communications with the BS110are to be transmitted or received via the relay UE305, and accordingly, may transmit or receive the one or more communications via the relay UE305. In some aspects, the relay UE305may determine (e.g., based at least in part on receiving or transmitting an indication) that one or more communications between the BS110and the target UE305are to be transmitted or received via the relay UE305, and accordingly, may relay the one or more communications between the BS110and the target UE305. In some aspects, the BS110may determine (e.g., based at least in part on receiving or transmitting an indication) that one or more communications with the target UE305are to be transmitted or received via the relay UE305, and accordingly, may transmit or receive the one or more communications via the relay UE305.

As shown inFIG.4, the target UE305and the BS110may communicate HARQ feedback and/or downlink retransmissions via the relay UE305. As shown by reference number405, the BS110may transmit, and the target UE305may receive, a downlink communication. For example, the target UE305may receive the downlink communication on the first access link with the BS110. In some aspects, the downlink communication may be a downlink shared channel (DL-SCH) communication or a downlink control channel (DL-CCH) communication. In some aspects, the downlink communication is an initial transmission that is a first redundancy version (RV) of the downlink communication (e.g., RV 0).

In some aspects, the BS110may transmit the downlink communication (e.g., RV 0) to the relay UE305instead of to the target UE305. In such a case, the BS110may transmit the downlink communication on the second access link with the relay UE305. The relay UE305may transmit the received downlink communication to the target UE305on the sidelink with the target UE305.

As shown by reference number410, the target UE305may transmit, and the relay UE305may receive, HARQ feedback for the downlink communication. For example, the target UE305may transmit the HARQ feedback on the sidelink with the relay UE305. The HARQ feedback may be an acknowledgment (ACK) or a negative ACK (NACK) for the downlink communication.

As shown by reference number415, the relay UE305may transmit, and the BS110may receive, the HARQ feedback received from the target UE305. For example, the relay UE305may transmit the HARQ feedback on the second access link with the BS110. In this way, the relay UE305may relay the HARQ feedback, which originated at the target UE305, to the BS110.

As shown by reference number420, the BS110may transmit, and the relay UE305may receive, a retransmission of the downlink communication. For example, the BS110may transmit the retransmission of the downlink communication on the second access link with the relay UE305. In some aspects, the BS110may transmit the retransmission to the target UE305(e.g., on the first access link) instead of to the relay UE305. The BS110may transmit the retransmission of the downlink communication in connection with receiving a NACK for the downlink communication. In some aspects, the retransmission may be a second RV of the downlink communication (e.g., RV 2, RV 3, and/or the like) that is different from the first RV of the downlink communication (e.g., that is associated with the initial transmission).

In some aspects, the relay UE305may forward the retransmission without decoding the retransmission. Alternatively, the relay UE305may decode the retransmission upon receiving the retransmission from the BS110, and re-encode (e.g., regenerate) the retransmission for relaying to the target UE305. In some aspects, the relay UE305may decode the retransmission based at least in part on an initial transmission (e.g., RV 0) or based at least in part on a previous transmission (e.g., a previous RV) that was decoded by the target UE305. In some aspects, whether the relay UE305is to forward the retransmission without decoding, or is to decode and re-encode the retransmission, may be according to a configuration or a capability of the relay UE305.

As shown by reference number425, the relay UE305may transmit, and the target UE305may receive, the retransmission (e.g., the forwarded retransmission or the re-encoded retransmission). For example, the relay UE305may transmit the retransmission on the sidelink with the target UE305. In this way, the relay UE305may relay the retransmission, which originated at the BS110, to the target UE305.

The target UE305may transmit additional HARQ feedback (e.g., to the retransmission) and/or the BS110may transmit additional retransmissions (e.g., in connection with receiving additional NACK feedback), in a manner similar to that described above.

As shown inFIG.5, the target UE305and the BS110may communicate uplink retransmissions and/or downlink control communications scheduling the uplink retransmissions via the relay UE305. As shown by reference number505, the target UE305may transmit, and the BS110may receive, an uplink communication. For example, the target UE305may transmit the uplink communication on the first access link with the BS110. In some aspects, the uplink communication may be an uplink shared channel (UL-SCH) communication or an uplink control channel (UL-CCH) communication. In some aspects, the uplink communication is an initial transmission that is a first RV of the uplink communication (e.g., RV 0).

In some aspects, the target UE305may transmit the uplink communication (e.g., RV 0) to the relay UE305instead of to the BS110. In such a case, the target UE305may transmit the uplink communication on the sidelink with the relay UE305. The relay UE305may transmit the received uplink communication to the BS110on the second access link with the BS110.

As shown by reference number510, the target UE305may transmit, and the relay UE305may receive, a retransmission of the uplink communication. For example, the target UE305may transmit the retransmission of the uplink communication on the sidelink with the relay UE305. In some aspects, the target UE305may transmit the retransmission of the uplink communication in connection with receiving a DL-CCH communication (e.g., that includes DCI) that schedules the retransmission. In some aspects, the BS110may transmit, and the target UE305may receive, the DL-CCH on the first access link. In some aspects, the BS110may transmit, and the relay UE305may receive, the DL-CCH on the second access link, and the relay UE305may relay the DL-CCH to the target UE305on the sidelink. In some aspects, the retransmission may be a second RV of the uplink communication (e.g., RV 2, RV 3, and/or the like) that is different from the first RV of the uplink communication (e.g., that is associated with the initial transmission).

In some aspects, the relay UE305may forward the retransmission without decoding the retransmission. Alternatively, the relay UE305may decode the retransmission upon receiving the retransmission from the target UE305, and re-encode (e.g., regenerate) the retransmission for relaying to the BS110, in a manner similar to that described above.

As shown by reference number515, the relay UE305may transmit, and the BS110may receive, the retransmission (e.g., the forwarded retransmission or the re-encoded retransmission). For example, the relay UE305may transmit the retransmission on the second access link with the BS110. In this way, the relay UE305may relay the retransmission, which originated at the target UE305, to the BS110.

The BS110may transmit additional downlink control communications (e.g., including DCI that schedules a retransmission) and/or the target UE305may transmit additional retransmissions (e.g., in connection with receiving additional downlink control communications), in a manner similar to that described above.

As shown inFIG.6, the target UE305and the BS110may communicate control communications via the relay UE305. As shown by reference number605, the target UE305may transmit, and the relay UE305may receive, an uplink control communication (e.g., a UL-CCH communication) for the BS110. For example, the target UE305may transmit the uplink control communication on the sidelink with the relay UE305. The uplink control communication may include a scheduling request for an uplink data communication of the target UE305.

As shown by reference number610, the relay UE305may transmit, and the BS110may receive, the uplink control communication received from the target UE305. For example, the relay UE305may transmit the uplink control communication on the second access link with the BS110. In this way, the relay UE305may relay the uplink control communication, which originated at the target UE305, to the BS110.

As shown by reference number615, the BS110may transmit, and the relay UE305may receive, a downlink control communication (e.g., a DL-CCH communication). For example, the BS110may transmit the downlink control communication on the second access link with the relay UE305. The downlink control communication may include DCI that schedules a communication for the target UE305. In some aspects, the DCI may schedule an uplink communication for the target UE305. For example, the BS110may transmit the downlink control communication in connection with receiving the uplink control communication (e.g., that includes a scheduling request) that originated at the target UE305. In some aspects, the DCI may schedule a downlink communication for the target UE305.

As shown by reference number620, the relay UE305may transmit, and the target UE305may receive, the downlink control communication received from the BS110. For example, the relay UE305may transmit the downlink control communication on the sidelink with the target UE305. In this way, the relay UE305may relay the downlink control communication, which originated at the BS110, to the target UE305.

As shown by reference number625, the target UE305may transmit, and the BS110may receive, an uplink communication (e.g., a UL-SCH communication). For example, the target UE305may transmit the uplink communication on the first access link with the BS110. The target UE305may transmit the uplink communication in accordance with DCI of the downlink control communication (e.g., that was received via the relay UE305). Accordingly, the target UE305may transmit the uplink communication in connection with transmitting the uplink control communication (e.g., to the relay UE305).

As shown by reference number630, the BS110may transmit, and the target UE305may receive, a downlink communication (e.g., a DL-SCH communication). For example, the target UE305may receive the downlink communication on the first access link with the BS110. The target UE305may receive the uplink communication in accordance with DCI of the downlink control communication (e.g., that was received via the relay UE305).

The BS110may transmit additional downlink control communications (e.g., scheduling a downlink communication or an uplink communication) and/or the target UE305may transmit additional uplink control communications (e.g., including a scheduling request), in a manner similar to that described above.

As indicated above,FIGS.4-6are provided as examples. Other examples may differ from what is described with respect toFIGS.4-6.

FIG.7is a diagram illustrating an example process700performed, for example, by a UE, in accordance with various aspects of the present disclosure. Example process700is an example where the UE (e.g., UE120, UE305, and/or the like) performs operations associated with communication via sidelink relay.

As shown inFIG.7, in some aspects, process700may include determining that one or more communications with a base station are to be transmitted or received via a relay UE, wherein the one or more communications include at least one of HARQ feedback, a retransmission, or a control communication (block710). For example, the UE (e.g., using controller/processor280and/or the like) may determine that one or more communications with a base station are to be transmitted or received via a relay UE, as described above. In some aspects, the one or more communications include at least one of HARQ feedback, a retransmission, or a control communication.

As further shown inFIG.7, in some aspects, process700may include transmitting or receiving the one or more communications via the relay UE (block720). For example, the UE (e.g., using controller/processor280, transmit processor264, TX MIMO processor266, MOD254, antenna252, DEMOD254, MIMO detector256, receive processor258, and/or the like) may transmit or receive the one or more communications via the relay UE, as described above.

Process700may 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, transmitting or receiving the one or more communications may include receiving a downlink communication on an access link with the base station or on a sidelink with the relay UE, and transmitting HARQ feedback, for the downlink communication, on the sidelink with the relay UE. In a second aspect, alone or in combination with the first aspect, transmitting or receiving the one or more communications may include receiving a retransmission of the downlink communication on the access link with the base station or on the sidelink with the relay UE. In a third aspect, alone or in combination with one or more of the first and second aspects, the retransmission is received on the sidelink with the relay UE, and the retransmission has been decoded and re-encoded by the relay UE.

In a fourth aspect, alone or in combination with one or more of the first through third aspects, transmitting or receiving the one or more communications may include transmitting an uplink communication on an access link with the base station or on a sidelink with the relay UE, and transmitting a retransmission of the uplink communication on the sidelink with the relay UE. In a fifth aspect, alone or in combination with one or more of the first through fourth aspects, transmitting or receiving the one or more communications may include receiving a downlink control channel communication, that schedules the retransmission, on the access link with the base station or on the sidelink with the relay UE.

In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, transmitting or receiving the one or more communications may include receiving a downlink control channel communication on a sidelink with the relay UE, and receiving a downlink shared channel communication on an access link with the base station. In a seventh aspect, alone or in combination with one or more of the first through sixth aspects, transmitting or receiving the one or more communications may include transmitting an uplink control channel communication on a sidelink with the relay UE, and transmitting an uplink shared channel communication on an access link with the base station.

In an eighth aspect, alone or in combination with one or more of the first through seventh aspects, process700includes receiving an indication that communication between the base station and the UE is to be via the relay UE based at least in part on at least one of: the UE being a low-tier UE and the relay UE being a high-tier UE; the UE being associated with a lower capability than the relay UE; an access link of the UE having a lesser quality than an access link of the relay UE; or the UE being located further from the base station than the relay UE. In a ninth aspect, alone or in combination with one or more of the first through eighth aspects, the indication is received via radio resource control signaling, a medium access control control element, or downlink control information.

In a tenth aspect, alone or in combination with one or more of the first through ninth aspects, process700includes transmitting a capability report that indicates whether the UE supports using the relay UE for one or more of: relaying an initial transmission; relaying HARQ feedback; relaying a retransmission; relaying a data channel communication; or relaying a control channel communication.

In an eleventh aspect, alone or in combination with one or more of the first through tenth aspects, process700includes receiving a capability report that indicates whether the relay UE supports one or more of: relaying an initial transmission; relaying HARQ feedback; relaying a retransmission; relaying a data channel communication; or relaying a control channel communication.

AlthoughFIG.7shows example blocks of process700, in some aspects, process700may include additional blocks, fewer blocks, different blocks, or differently arranged blocks than those depicted inFIG.7. Additionally, or alternatively, two or more of the blocks of process700may be performed in parallel.

FIG.8is a diagram illustrating an example process800performed, for example, by a relay UE, in accordance with various aspects of the present disclosure. Example process800is an example where the relay UE (e.g., UE120, UE305, and/or the like) performs operations associated with communication via sidelink relay.

As shown inFIG.8, in some aspects, process800may include determining that one or more communications between a base station and a UE are to be transmitted or received via a relay UE, wherein the one or more communications include at least one of HARQ feedback, a retransmission, or a control communication (block810). For example, the relay UE (e.g., using controller/processor280and/or the like) may determine that one or more communications between a base station and a UE are to be transmitted or received via the relay UE, as described above. In some aspects, the one or more communications include at least one of HARQ feedback, a retransmission, or a control communication.

As further shown inFIG.8, in some aspects, process800may include relaying the one or more communications between the base station and the UE (block820). For example, the relay UE (e.g., using controller/processor280, transmit processor264, TX MIMO processor266, MOD254, antenna252, DEMOD254, MIMO detector256, receive processor258, and/or the like) may relay the one or more communications between the base station and the UE, as described above.

Process800may 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, relaying the one or more communications may include receiving a downlink communication on an access link with the base station, and transmitting the downlink communication on a sidelink with the UE.

In a second aspect, alone or in combination with the first aspect, relaying the one or more communications may include receiving HARQ feedback, for a downlink communication, on a sidelink with the UE, and transmitting the HARQ feedback on an access link with the base station. In a third aspect, alone or in combination with one or more of the first and second aspects, relaying the one or more communications may include receiving a retransmission of the downlink communication on the access link with the base station, and transmitting the retransmission on the sidelink with the UE. In a fourth aspect, alone or in combination with one or more of the first through third aspects, process800includes decoding and re-encoding the retransmission prior to transmitting the retransmission on the sidelink with the UE.

In a fifth aspect, alone or in combination with one or more of the first through fourth aspects, relaying the one or more communications may include receiving an uplink communication on a sidelink with the UE, and transmitting the uplink communication on an access link with the base station. In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, relaying the one or more communications may include receiving a retransmission, for the uplink communication, on the sidelink with the UE, and transmitting the retransmission on the access link with the base station. In a seventh aspect, alone or in combination with one or more of the first through sixth aspects, process800includes decoding and re-encoding the retransmission prior to transmitting the retransmission on the access link with the base station. In an eighth aspect, alone or in combination with one or more of the first through seventh aspects, relaying the one or more communications may include receiving a downlink control channel communication, that schedules the retransmission, on the access link with the base station, and transmitting the downlink control channel communication on the sidelink with the UE.

In a ninth aspect, alone or in combination with one or more of the first through eighth aspects, relaying the one or more communications may include receiving a downlink control channel communication on an access link with the base station, and transmitting the downlink control channel communication on a sidelink with the UE. In a tenth aspect, alone or in combination with one or more of the first through ninth aspects, relaying the one or more communications may include receiving an uplink control channel communication on a sidelink with the UE, and transmitting the uplink control channel communication on an access link with the base station.

In an eleventh aspect, alone or in combination with one or more of the first through tenth aspects, process800includes receiving an indication that communication between the base station and the UE is to be via the relay UE based at least in part on at least one of: the UE being a low-tier UE and the relay UE being a high-tier UE; the UE being associated with a lower capability than the relay UE; an access link of the UE having a lesser quality than an access link of the relay UE; or the UE being located further from the base station than the relay UE. In a twelfth aspect, alone or in combination with one or more of the first through eleventh aspects, the indication is received via radio resource control signaling, a medium access control control element, or downlink control information.

In a thirteenth aspect, alone or in combination with one or more of the first through twelfth aspects, process800includes receiving a capability report that indicates whether the UE supports using the relay UE for one or more of: relaying an initial transmission; relaying HARQ feedback; relaying a retransmission; relaying a data channel communication; or relaying a control channel communication.

In a fourteenth aspect, alone or in combination with one or more of the first through thirteenth aspects, process800includes transmitting a capability report that indicates whether the relay UE supports one or more of: relaying an initial transmission; relaying HARQ feedback; relaying a retransmission; relaying a data channel communication; or relaying a control channel communication.

AlthoughFIG.8shows example blocks of process800, in some aspects, process800may include additional blocks, fewer blocks, different blocks, or differently arranged blocks than those depicted inFIG.8. Additionally, or alternatively, two or more of the blocks of process800may be performed in parallel.

FIG.9is a diagram illustrating an example process900performed, for example, by a BS, in accordance with various aspects of the present disclosure. Example process900is an example where the BS (e.g., BS110and/or the like) performs operations associated with communication via sidelink relay.

As shown inFIG.9, in some aspects, process900may include determining that one or more communications with a UE are to be transmitted or received via a relay UE, wherein the one or more communications include at least one of HARQ feedback, a retransmission, or a control communication (block910). For example, the BS (e.g., using controller/processor240and/or the like) may determine that one or more communications with a UE are to be transmitted or received via a relay UE, as described above. In some aspects, the one or more communications include at least one of HARQ feedback, a retransmission, or a control communication.

As further shown inFIG.9, in some aspects, process900may include transmitting or receiving the one or more communications via the relay UE (block920). For example, the BS (e.g., using controller/processor240, transmit processor220, TX MIMO processor230, MOD232, antenna234, DEMOD232, MIMO detector236, receive processor238, and/or the like) may transmit or receive the one or more communications via the relay UE, as described above.

Process900may 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, transmitting or receiving the one or more communications may include transmitting a downlink communication on an access link with the UE or on an access link with the relay UE, and receiving HARQ feedback, for the downlink communication, on the access link with the relay UE. In a second aspect, alone or in combination with the first aspect, transmitting or receiving the one or more communications may include transmitting a retransmission of the downlink communication on the access link with the UE or on the access link with the relay UE.

In a third aspect, alone or in combination with one or more of the first and second aspects, transmitting or receiving the one or more communications may include receiving an uplink communication on an access link with the UE or on an access link with the relay UE, and receiving a retransmission of the uplink communication on the access link with the relay UE. In a fourth aspect, alone or in combination with one or more of the first through third aspects, the retransmission has been decoded and re-encoded by the relay UE. In a fifth aspect, alone or in combination with one or more of the first through fourth aspects, transmitting or receiving the one or more communications may include transmitting a downlink control channel communication, that schedules the retransmission, on the access link with the UE or on the access link with the relay UE.

In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, transmitting or receiving the one or more communications may include transmitting a downlink control channel communication on an access link with the relay UE, and transmitting a downlink shared channel communication on an access link with the UE. In a seventh aspect, alone or in combination with one or more of the first through sixth aspects, transmitting or receiving the one or more communications may include receiving an uplink control channel communication on an access link with the relay UE, and receiving an uplink shared channel communication on an access link with the UE.

In an eighth aspect, alone or in combination with one or more of the first through seventh aspects, process900includes transmitting an indication that communication between the base station and the UE is to be via the relay UE based at least in part on at least one of: the UE being a low-tier UE and the relay UE being a high-tier UE; the UE being associated with a lower capability than the relay UE; an access link of the UE having a lesser quality than an access link of the relay UE; or the UE being located further from the base station than the relay UE. In a ninth aspect, alone or in combination with one or more of the first through eighth aspects, the indication is transmitted via radio resource control signaling, a medium access control control element, or downlink control information.

In a tenth aspect, alone or in combination with one or more of the first through ninth aspects, process900includes receiving a capability report that indicates whether the UE supports using the relay UE for one or more of: relaying an initial transmission; relaying HARQ feedback; relaying a retransmission; relaying a data channel communication; or relaying a control channel communication.

In an eleventh aspect, alone or in combination with one or more of the first through tenth aspects, process900includes receiving a capability report that indicates whether the relay UE supports one or more of: relaying an initial transmission; relaying HARQ feedback; relaying a retransmission; relaying a data channel communication; or relaying a control channel communication.

AlthoughFIG.9shows example blocks of process900, in some aspects, process900may include additional blocks, fewer blocks, different blocks, or differently arranged blocks than those depicted inFIG.9. Additionally, or alternatively, two or more of the blocks of process900may be performed in parallel.

FIG.10is a diagram of an example apparatus1000for wireless communication, in accordance with various aspects of the present disclosure. The apparatus1000may be a UE (e.g., a relay UE), or a UE may include the apparatus1000. In some aspects, the apparatus1000includes a reception component1002and a transmission component1004, which may be in communication with one another (for example, via one or more buses and/or one or more other components). As shown, the apparatus1000may communicate with another apparatus1006(such as a UE, a base station, or another wireless communication device) using the reception component1002and the transmission component1004. As further shown, the apparatus1000may include one or more of a determination component1008or an encoding component1010, among other examples.

In some aspects, the apparatus1000may be configured to perform one or more operations described herein in connection withFIGS.4-6. Additionally or alternatively, the apparatus1000may be configured to perform one or more processes described herein, such as process700ofFIG.7, process800ofFIG.8, or a combination thereof. In some aspects, the apparatus1000and/or one or more components shown inFIG.10may include one or more components of the UE described above in connection withFIG.2. Additionally, or alternatively, one or more components shown inFIG.10may be implemented within one or more components described above in connection withFIG.2. Additionally or alternatively, one or more components of the set of components may be implemented at least in part as software stored in a memory. For example, a component (or a portion of a component) may be implemented as instructions or code stored in a non-transitory computer-readable medium and executable by a controller or a processor to perform the functions or operations of the component.

The reception component1002may receive communications, such as reference signals, control information, data communications, or a combination thereof, from the apparatus1006. The reception component1002may provide received communications to one or more other components of the apparatus1000. In some aspects, the reception component1002may perform signal processing on the received communications (such as filtering, amplification, demodulation, analog-to-digital conversion, demultiplexing, deinterleaving, de-mapping, equalization, interference cancellation, or decoding, among other examples), and may provide the processed signals to the one or more other components of the apparatus1006. In some aspects, the reception component1002may include one or more antennas, a demodulator, a MIMO detector, a receive processor, a controller/processor, a memory, or a combination thereof, of the UE described above in connection withFIG.2.

The transmission component1004may transmit communications, such as reference signals, control information, data communications, or a combination thereof, to the apparatus1006. In some aspects, one or more other components of the apparatus1006may generate communications and may provide the generated communications to the transmission component1004for transmission to the apparatus1006. In some aspects, the transmission component1004may perform signal processing on the generated communications (such as filtering, amplification, modulation, digital-to-analog conversion, multiplexing, interleaving, mapping, or encoding, among other examples), and may transmit the processed signals to the apparatus1006. In some aspects, the transmission component1004may include one or more antennas, a modulator, a transmit MIMO processor, a transmit processor, a controller/processor, a memory, or a combination thereof, of the UE described above in connection withFIG.2. In some aspects, the transmission component1004may be collocated with the reception component1002in a transceiver.

The determination component1008may determine that one or more communications with a base station are to be transmitted or received via a relay UE. In some aspects, the one or more communications include at least one of HARQ feedback, a retransmission, or a control communication. In some aspects, the determination component1008may include a controller/processor, a memory, or a combination thereof, of the UE described above in connection withFIG.2. The transmission component1004may transmit the one or more communications via the relay UE. The reception component1002may receive the one or more communications via the relay UE.

The reception component1002may receive an indication that communication between the base station and the UE is to be via the relay UE based at least in part on at least one of the UE being a low-tier UE and the relay UE being a high-tier UE; the UE being associated with a lower capability than the relay UE; an access link of the UE having a lesser quality than an access link of the relay UE; or the UE being located further from the base station than the relay UE.

The transmission component1004may transmit a capability report that indicates whether the UE supports using the relay UE for one or more of relaying an initial transmission; relaying HARQ feedback; relaying a retransmission; relaying a data channel communication; or relaying a control channel communication.

The reception component1002may receive a capability report that indicates whether the relay UE supports one or more of relaying an initial transmission; relaying HARQ feedback; relaying a retransmission; relaying a data channel communication; or relaying a control channel communication.

The determination component1008may determine that one or more communications between a base station and a UE are to be transmitted or received via the relay UE. In some aspects, the one or more communications include at least one of HARQ feedback, a retransmission, or a control communication. The transmission component1004may relay the one or more communications between the base station and the UE.

The encoding component1010may decode and re-encode the retransmission prior to transmitting the retransmission on the sidelink with the UE. In some aspects, the encoding component1010may include a demodulator, a MIMO detector, a receive processor, a modulator, a transmit MIMO processor, a transmit processor, a controller/processor, a memory, or a combination thereof, of the UE described above in connection withFIG.2. The encoding component1010may decode and re-encode the retransmission prior to transmitting the retransmission on the access link with the base station.

The reception component1002may receive an indication that communication between the base station and the UE is to be via the relay UE based at least in part on at least one of the UE being a low-tier UE and the relay UE being a high-tier UE; the UE being associated with a lower capability than the relay UE; an access link of the UE having a lesser quality than an access link of the relay UE; or the UE being located further from the base station than the relay UE.

The reception component1002may receive a capability report that indicates whether the UE supports using the relay UE for one or more of relaying an initial transmission; relaying HARQ feedback; relaying a retransmission; relaying a data channel communication; or relaying a control channel communication.

The transmission component1004may transmit a capability report that indicates whether the relay UE supports one or more of relaying an initial transmission; relaying HARQ feedback; relaying a retransmission; relaying a data channel communication; or relaying a control channel communication.

The quantity and arrangement of components shown inFIG.10are provided as an example. In practice, there may be additional components, fewer components, different components, or differently arranged components than those shown inFIG.10. Furthermore, two or more components shown inFIG.10may be implemented within a single component, or a single component shown inFIG.10may be implemented as multiple, distributed components. Additionally or alternatively, a set of (one or more) components shown inFIG.10may perform one or more functions described as being performed by another set of components shown inFIG.10.

FIG.11is a diagram of an example apparatus1100for wireless communication, in accordance with various aspects of the present disclosure. The apparatus1100may be a base station, or a base station may include the apparatus1100. In some aspects, the apparatus1100includes a reception component1102and a transmission component1104, which may be in communication with one another (for example, via one or more buses and/or one or more other components). As shown, the apparatus1100may communicate with another apparatus1106(such as a UE, a base station, or another wireless communication device) using the reception component1102and the transmission component1104. As further shown, the apparatus1100may include a determination component1108, among other examples.

In some aspects, the apparatus1100may be configured to perform one or more operations described herein in connection withFIGS.4-6. Additionally or alternatively, the apparatus1100may be configured to perform one or more processes described herein, such as process900ofFIG.9, or a combination thereof. In some aspects, the apparatus1100and/or one or more components shown inFIG.11may include one or more components of the base station described above in connection withFIG.2. Additionally, or alternatively, one or more components shown inFIG.11may be implemented within one or more components described above in connection withFIG.2. Additionally or alternatively, one or more components of the set of components may be implemented at least in part as software stored in a memory. For example, a component (or a portion of a component) may be implemented as instructions or code stored in a non-transitory computer-readable medium and executable by a controller or a processor to perform the functions or operations of the component.

The reception component1102may receive communications, such as reference signals, control information, data communications, or a combination thereof, from the apparatus1106. The reception component1102may provide received communications to one or more other components of the apparatus1100. In some aspects, the reception component1102may perform signal processing on the received communications (such as filtering, amplification, demodulation, analog-to-digital conversion, demultiplexing, deinterleaving, de-mapping, equalization, interference cancellation, or decoding, among other examples), and may provide the processed signals to the one or more other components of the apparatus1106. In some aspects, the reception component1102may include one or more antennas, a demodulator, a MIMO detector, a receive processor, a controller/processor, a memory, or a combination thereof, of the base station described above in connection withFIG.2.

The transmission component1104may transmit communications, such as reference signals, control information, data communications, or a combination thereof, to the apparatus1106. In some aspects, one or more other components of the apparatus1106may generate communications and may provide the generated communications to the transmission component1104for transmission to the apparatus1106. In some aspects, the transmission component1104may perform signal processing on the generated communications (such as filtering, amplification, modulation, digital-to-analog conversion, multiplexing, interleaving, mapping, or encoding, among other examples), and may transmit the processed signals to the apparatus1106. In some aspects, the transmission component1104may include one or more antennas, a modulator, a transmit MIMO processor, a transmit processor, a controller/processor, a memory, or a combination thereof, of the base station described above in connection withFIG.2. In some aspects, the transmission component1104may be collocated with the reception component1102in a transceiver.

The determination component1108may determine that one or more communications with a UE are to be transmitted or received via a relay UE. In some aspects, the one or more communications include at least one of HARQ feedback, a retransmission, or a control communication. In some aspects, the determination component1108may include a controller/processor, a memory, or a combination thereof, of the base station described above in connection withFIG.2. The transmission component1104may transmit the one or more communications via the relay UE. The reception component1102may receive the one or more communications via the relay UE.

The transmission component1104may transmit an indication that communication between the base station and the UE is to be via the relay UE based at least in part on at least one of the UE being a low-tier UE and the relay UE being a high-tier UE; the UE being associated with a lower capability than the relay UE; an access link of the UE having a lesser quality than an access link of the relay UE; or the UE being located further from the base station than the relay UE.

The reception component1102may receive a capability report that indicates whether the UE supports using the relay UE for one or more of relaying an initial transmission; relaying HARQ feedback; relaying a retransmission; relaying a data channel communication; or relaying a control channel communication.

The reception component1102may receive a capability report that indicates whether the relay UE supports one or more of relaying an initial transmission; relaying HARQ feedback; relaying a retransmission; relaying a data channel communication; or relaying a control channel communication.

The quantity and arrangement of components shown inFIG.11are provided as an example. In practice, there may be additional components, fewer components, different components, or differently arranged components than those shown inFIG.11. Furthermore, two or more components shown inFIG.11may be implemented within a single component, or a single component shown inFIG.11may be implemented as multiple, distributed components. Additionally or alternatively, a set of (one or more) components shown inFIG.11may perform one or more functions described as being performed by another set of components shown inFIG.11.

The following provides an overview of aspects of the present disclosure:

Aspect 1: A method of wireless communication performed by a UE, comprising: determining that one or more communications with a base station are to be transmitted or received via a relay UE, wherein the one or more communications include at least one of HARQ feedback, a retransmission, or a control communication; and transmitting or receiving the one or more communications via the relay UE.

Aspect 2: The method of aspect 1, wherein transmitting or receiving the one or more communications comprises: receiving a downlink communication on a sidelink with the relay UE; and transmitting HARQ feedback, for the downlink communication, on the sidelink with the relay UE.

Aspect 3: The method of any of aspects 1 through 2, wherein transmitting or receiving the one or more communications further comprises: receiving a retransmission of the downlink communication on the sidelink with the relay UE.

Aspect 4: The method of any of aspects 1 through 3, wherein the retransmission is received on the sidelink with the relay UE, and wherein the retransmission has been decoded and re-encoded by the relay UE.

Aspect 5: The method of any of aspects 1 through 4, wherein transmitting or receiving the one or more communications comprises: transmitting an uplink communication on a sidelink with the relay UE; and transmitting a retransmission of the uplink communication on the sidelink with the relay UE.

Aspect 6: The method of any of aspects 1 through 5, wherein transmitting or receiving the one or more communications further comprises: receiving a downlink control channel communication, that schedules the retransmission, on the sidelink with the relay UE.

Aspect 7: The method of any of aspects 1 through 6, wherein transmitting or receiving the one or more communications comprises: receiving a downlink control channel communication on a sidelink with the relay UE; and receiving a downlink shared channel communication on an access link with the base station.

Aspect 8: The method of any of aspects 1 through 7, wherein transmitting or receiving the one or more communications comprises: transmitting an uplink control channel communication on a sidelink with the relay UE; and transmitting an uplink shared channel communication on an access link with the base station.

Aspect 9: The method of any of aspects 1 through 8, further comprising receiving an indication that communication between the base station and the UE is to be via the relay UE based at least in part on at least one of: the UE being a low-tier UE and the relay UE being a high-tier UE; the UE being associated with a lower capability than the relay UE; an access link of the UE having a lesser quality than an access link of the relay UE; or the UE being located further from the base station than the relay UE.

Aspect 10: The method of aspect 9, wherein the indication is received via RRC signaling, a MAC-CE, or DCI.

Aspect 11: The method of any of aspects 1 through 10, further comprising transmitting a capability report that indicates whether the UE supports using the relay UE for one or more of: relaying an initial transmission; relaying HARQ feedback; relaying a retransmission; relaying a data channel communication; or relaying a control channel communication.

Aspect 12: The method of any of aspects 1 through 11, further comprising receiving a capability report that indicates whether the relay UE supports one or more of: relaying an initial transmission; relaying HARQ feedback; relaying a retransmission; relaying a data channel communication; or relaying a control channel communication.

Aspect 13: A method of wireless communication performed by a relay UE, comprising: determining that one or more communications between a base station and a UE are to be transmitted or received via the relay UE, wherein the one or more communications include at least one of HARQ feedback, a retransmission, or a control communication; and relaying the one or more communications between the base station and the UE.

Aspect 14: The method of aspect 13, wherein relaying the one or more communications comprises: receiving a downlink communication on an access link with the base station; and transmitting the downlink communication on a sidelink with the UE.

Aspect 15: The method of any of aspects 13 through 14, wherein relaying the one or more communications comprises: receiving HARQ feedback, for a downlink communication, on a sidelink with the UE; and transmitting the HARQ feedback on an access link with the base station.

Aspect 16: The method of any of aspects 13 through 15, wherein relaying the one or more communications further comprises: receiving a retransmission of the downlink communication on the access link with the base station; and transmitting the retransmission on the sidelink with the UE.

Aspect 17: The method of any of aspects 13 through 16, further comprising decoding and re-encoding the retransmission prior to transmitting the retransmission on the sidelink with the UE.

Aspect 18: The method of any of aspects 13 through 17, wherein relaying the one or more communications comprises: receiving an uplink communication on a sidelink with the UE; and transmitting the uplink communication on an access link with the base station.

Aspect 19: The method of any of aspects 13 through 18, wherein relaying the one or more communications further comprises: receiving a retransmission, for the uplink communication, on the sidelink with the UE; and transmitting the retransmission on the access link with the base station.

Aspect 20: The method of any of aspects 13 through 19, further comprising: decoding and re-encoding the retransmission prior to transmitting the retransmission on the access link with the base station.

Aspect 21: The method of any of aspects 13 through 20, wherein relaying the one or more communications further comprises: receiving a downlink control channel communication, that schedules the retransmission, on the access link with the base station; and transmitting the downlink control channel communication on the sidelink with the UE.

Aspect 22: The method of any of aspects 13 through 21, wherein relaying the one or more communications comprises: receiving a downlink control channel communication on an access link with the base station; and transmitting the downlink control channel communication on a sidelink with the UE.

Aspect 23: The method of any of aspects 13 through 22, wherein relaying the one or more communications comprises: receiving an uplink control channel communication on a sidelink with the UE; and transmitting the uplink control channel communication on an access link with the base station.

Aspect 24: The method of any of aspects 13 through 23, further comprising receiving an indication that communication between the base station and the UE is to be via the relay UE based at least in part on at least one of: the UE being a low-tier UE and the relay UE being a high-tier UE; the UE being associated with a lower capability than the relay UE; an access link of the UE having a lesser quality than an access link of the relay UE; or the UE being located further from the base station than the relay UE.

Aspect 25: The method of aspect 24, wherein the indication is received via RRC signaling, a MAC-CE, or DCI.

Aspect 26: The method of any of aspects 13 through 25, further comprising receiving a capability report that indicates whether the UE supports using the relay UE for one or more of: relaying an initial transmission; relaying HARQ feedback; relaying a retransmission; relaying a data channel communication; or relaying a control channel communication.

Aspect 27: The method of any of aspects 13 through 26, further comprising: transmitting a capability report that indicates whether the relay UE supports one or more of: relaying an initial transmission; relaying HARQ feedback; relaying a retransmission; relaying a data channel communication; or relaying a control channel communication.

Aspect 28: A method of wireless communication performed by a base station, comprising: determining that one or more communications with a UE are to be transmitted or received via a relay UE, wherein the one or more communications include at least one of HARQ feedback, a retransmission, or a control communication; and transmitting or receiving the one or more communications via the relay UE.

Aspect 29: The method of aspect 28, wherein transmitting or receiving the one or more communications comprises: transmitting a downlink communication on an access link with the relay UE; and receiving HARQ feedback, for the downlink communication, on the access link with the relay UE.

Aspect 30: The method of any of aspects 28 through 29, wherein transmitting or receiving the one or more communications further comprises: transmitting a retransmission of the downlink communication on the access link with the relay UE.

Aspect 31: The method of any of aspects 28 through 30, wherein transmitting or receiving the one or more communications comprises: receiving an uplink communication on an access link with the relay UE; and receiving a retransmission of the uplink communication on the access link with the relay UE.

Aspect 32: The method of any of aspects 28 through 31, wherein the retransmission has been decoded and re-encoded by the relay UE.

Aspect 33: The method of any of aspects 28 through 32, wherein transmitting or receiving the one or more communications further comprises: transmitting a downlink control channel communication, that schedules the retransmission, on the access link with the relay UE.

Aspect 34: The method of any of aspects 28 through 33, wherein transmitting or receiving the one or more communications comprises: transmitting a downlink control channel communication on an access link with the relay UE; and transmitting a downlink shared channel communication on an access link with the UE.

Aspect 35: The method of any of aspects 28 through 34, wherein transmitting or receiving the one or more communications comprises: receiving an uplink control channel communication on an access link with the relay UE; and receiving an uplink shared channel communication on an access link with the UE.

Aspect 36: The method of any of aspects 28 through 35, further comprising transmitting an indication that communication between the base station and the UE is to be via the relay UE based at least in part on at least one of: the UE being a low-tier UE and the relay UE being a high-tier UE; the UE being associated with a lower capability than the relay UE; an access link of the UE having a lesser quality than an access link of the relay UE; or the UE being located further from the base station than the relay UE.

Aspect 37: The method of aspect 36, wherein the indication is transmitted via RRC signaling, a MAC-CE, or DCI.

Aspect 38: The method of any of aspects 28 through 37, further comprising: receiving a capability report that indicates whether the UE supports using the relay UE for one or more of: relaying an initial transmission; relaying HARQ feedback; relaying a retransmission; relaying a data channel communication; or relaying a control channel communication.

Aspect 39: The method of any of aspects 28 through 38, further comprising: receiving a capability report that indicates whether the relay UE supports one or more of: relaying an initial transmission; relaying HARQ feedback; relaying a retransmission; relaying a data channel communication; or relaying a control channel communication.

Aspect 40: An apparatus for wireless communication at a device, comprising a processor; memory coupled with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform the method of one or more aspects of aspects 1-39.

Aspect 41: A device for wireless communication, comprising a memory and one or more processors coupled to the memory, the memory and the one or more processors configured to perform the method of one or more aspects of aspects 1-39.

Aspect 42: An apparatus for wireless communication, comprising at least one means for performing the method of one or more aspects of aspects 1-39.

Aspect 43: A non-transitory computer-readable medium storing code for wireless communication, the code comprising instructions executable by a processor to perform the method of one or more aspects of aspects 1-39.

Aspect 44: 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 device, cause the device to perform the method of one or more aspects of aspects 1-39.

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.

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.

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.

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.” 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.