UNICAST MESSAGE AND MULTICAST MESSAGE MULTIPLEXING

A method for wireless communication at a first user equipment (UE) includes multiplexing a unicast message for a second UE with a multicast message for a group of UEs that includes the second UE. The unicast message may be multiplexed on one or more resources of a resource set associated with transmitting the multicast message. The method also includes transmitting, to the group of UEs, the multiplexed unicast and multicast messages. The method further includes receiving, from the second UE, one or more hybrid automatic repeat request (HARQ) feedback messages including first HARQ feedback for the unicast message and second HARQ feedback for the multicast message based on transmitting the multiplexed unicast and multicast messages.

FIELD OF THE DISCLOSURE

The present disclosure relates generally to wireless communications, and more specifically to multiplexing a unicast message intended for one user equipment (UE) of a group of UEs with a multicast message intended for the group of UEs.

BACKGROUND

Wireless communications systems are widely deployed to provide various telecommunications services such as telephony, video, data, messaging, and broadcasts. Typical wireless communications systems may employ multiple-access technologies capable of supporting communications with multiple users by sharing available system resources. Examples of such multiple-access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single-carrier frequency division multiple access (SC-FDMA) systems, and time division synchronous code division multiple access (TD-SCDMA) systems.

These multiple access technologies have been adopted in various telecommunications standards to provide a common protocol that enables different wireless devices to communicate on a municipal, national, regional, and even global level. An example telecommunications standard is fifth generation (5G) new radio (NR). 5G NR is part of a continuous mobile broadband evolution promulgated by Third Generation Partnership Project (3GPP) to meet new requirements associated with latency, reliability, security, scalability (for example, with Internet of Things (IoT)), and other requirements. 5G NR includes services associated with enhanced mobile broadband (eMBB), massive machine type communications (mMTC), and ultra-reliable low latency communications (URLLC). Some aspects of 5G NR may be based on the fourth generation (4G) long term evolution (LTE) standard. Narrowband (NB)-Internet of things (IoT) and enhanced machine-type communications (eMTC) are a set of enhancements to LTE for machine type communications. There exists a need for further improvements in 5G NR technology. These improvements may also be applicable to other multi-access technologies and the telecommunications standards that employ these technologies.

In some wireless communication systems, a network node (for example, a base station, a user equipment (UE), or a sidelink UE) may communicate with a group of UEs, via a multicast operation, or a specific UE, via a unicast operation. The specific UE may be one UE of the group of UEs or may be excluded from the group of UEs. In unicast operation examples, the network node may transmit one or more unicast messages for communications directed to the specific UE for point-to-point services, such as, for example, voice calling, text messaging, or video calling. In multicast operation examples, the network node may transmit one or more multicast messages to the group of UEs in a synchronized manner for point-to-multipoint services, such as, for example, event-related multimedia broadcasts.

SUMMARY

In one aspect of the present disclosure, a method for wireless communication at a first user equipment (UE) includes multiplexing a unicast message for a second UE with a multicast message for a group of UEs that includes the second UE. The unicast message may be multiplexed on one or more resources of a resource set associated with transmitting the multicast message. The method further includes transmitting, to the group of UEs, the multiplexed unicast and multicast messages. The method still further includes receiving, from the second UE, one or more HARQ feedback messages including first HARQ feedback for the unicast message and second HARQ feedback for the multicast message based on transmitting the multiplexed unicast and multicast messages.

Another aspect of the present disclosure is directed to an apparatus including means for multiplexing a unicast message for a second UE with a multicast message for a group of UEs that includes the second UE. The unicast message may be multiplexed on one or more resources of a resource set associated with transmitting the multicast message. The apparatus further includes means for transmitting, to the group of UEs, the multiplexed unicast and multicast messages. The apparatus still further includes means for receiving, from the second UE, one or more HARQ feedback messages including first HARQ feedback for the unicast message and second HARQ feedback for the multicast message based on transmitting the multiplexed unicast and multicast messages.

In another aspect of the present disclosure, a non-transitory computer-readable medium with non-transitory program code recorded thereon is disclosed. The program code is executed by a processor and includes program code to multiplex a unicast message for a second UE with a multicast message for a group of UEs that includes the second UE. The unicast message may be multiplexed on one or more resources of a resource set associated with transmitting the multicast message. The program code further includes program code to transmit, to the group of UEs, the multiplexed unicast and multicast messages. The program code still further includes program code to receive, from the second UE, one or more HARQ feedback messages including first HARQ feedback for the unicast message and second HARQ feedback for the multicast message based on transmitting the multiplexed unicast and multicast messages.

Another aspect of the present disclosure is directed to an apparatus for wireless communications at a first UE. The apparatus includes a processor and a memory coupled with the processor and storing instructions operable, when executed by the processor, to cause the apparatus to multiplex a unicast message for a second UE with a multicast message for a group of UEs that includes the second UE. The unicast message may be multiplexed on one or more resources of a resource set associated with transmitting the multicast message. Execution of the instructions further cause the apparatus to transmit, to the group of UEs, the multiplexed unicast and multicast messages. Execution of the instructions also cause the apparatus to receive, from the second UE, one or more HARQ feedback messages including first HARQ feedback for the unicast message and second HARQ feedback for the multicast message based on transmitting the multiplexed unicast and multicast messages.

In one aspect of the present disclosure, a method for wireless communication at a first UE includes receiving, from a network node, an RRC message configuring the first UE to transmit, to a second UE, a unicast message associated with a first priority, or to transmit, to a group of UEs that includes the second UE, a multicast message associated with a second priority different than the first priority, based on one of the first priority or the second priority satisfying a priority condition. The method further includes transmitting one of the unicast message or the multicast message based on one of the first priority or the second priority satisfying the priority condition. The method still further includes receiving, from the second UE, a HARQ feedback message based on transmitting the one of the unicast message or the multicast message.

Another aspect of the present disclosure is directed to an apparatus including means for receiving, from a network node, an RRC message configuring the first UE to transmit, to a second UE, a unicast message associated with a first priority, or to transmit, to a group of UEs that includes the second UE, a multicast message associated with a second priority different than the first priority, based on one of the first priority or the second priority satisfying a priority condition. The apparatus further includes means for transmitting one of the unicast message or the multicast message based on one of the first priority or the second priority satisfying the priority condition. The apparatus still further includes means for receiving, from the second UE, a HARQ feedback message based on transmitting the one of the unicast message or the multicast message.

In another aspect of the present disclosure, a non-transitory computer-readable medium with non-transitory program code recorded thereon is disclosed. The program code is executed by a processor and includes program code to receive, from a network node, an RRC message configuring the first UE to transmit, to a second UE, a unicast message associated with a first priority, or to transmit, to a group of UEs that includes the second UE, a multicast message associated with a second priority different than the first priority, based on one of the first priority or the second priority satisfying a priority condition. The program code further includes program code to transmit one of the unicast message or the multicast message based on one of the first priority or the second priority satisfying the priority condition. The program code still further includes program code to receive, from the second UE, a HARQ feedback message based on transmitting the one of the unicast message or the multicast message.

Another aspect of the present disclosure is directed to an apparatus for wireless communications at a first UE. The apparatus includes a processor and a memory coupled with the processor and storing instructions operable, when executed by the processor, to cause the apparatus to receive, from a network node, an RRC message configuring the first UE to transmit, to a second UE, a unicast message associated with a first priority, or to transmit, to a group of UEs that includes the second UE, a multicast message associated with a second priority different than the first priority, based on one of the first priority or the second priority satisfying a priority condition. Execution of the instructions also cause the apparatus to transmit one of the unicast message or the multicast message based on one of the first priority or the second priority satisfying the priority condition. Execution of the instructions further cause the apparatus to receive, from the second UE, a HARQ feedback message based on transmitting the one of the unicast message or the multicast message.

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

DETAILED DESCRIPTION

Various aspects of the disclosure are described more fully below 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, one skilled in the art should appreciate that the scope of the disclosure is intended to cover any aspect of the disclosure disclosed, 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. 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. It should be understood that any aspect of the disclosure disclosed may be embodied by one or more elements of a claim.

It should be noted that while aspects may be described using terminology associated with 5G wireless technologies, aspects of the present disclosure can be applied in later generations, including for 6G wireless technologies, or in other wireless communications systems.

In cellular communications networks, wireless devices may generally communicate with each other via access links with one or more network entities such as a base station or scheduling entity. Some cellular networks may also support device-to-device (D2D) communications that enable discovery of, and communications among, nearby devices using direct links between devices (for example, without passing through a base station, relay, or other network entity). D2D communications may also be referred to as point-to-point (P2P) communications. D2D communications may be implemented using licensed or unlicensed bands. Using D2D communications, devices can avoid some of the overhead that would otherwise be involved with routing to and from a network entity. D2D communications can also enable mesh networking and device-to-network relay functionality.

Vehicle-to-everything (V2X) communication is an example of D2D communication that is specifically geared toward automotive use cases. V2X communications may enable autonomous vehicles to communicate with each other. In some examples, V2X communications may enable a group of autonomous vehicles to share respective sensor information. For example, each autonomous vehicle may include multiple sensors or sensing technologies (for example, light detection and ranging (LiDAR), radar, cameras, etc.). In most cases, an autonomous vehicle's sensors are limited to detecting objects within the sensors' line of sight. In contrast, based on the sensor information shared via V2X communications, one or more autonomous vehicles in the group of autonomous vehicles may be made aware of an out of sight object. In such examples, the object may be within a line of sight of sensors associated with another autonomous vehicle in the group of autonomous vehicles. Additionally, or alternatively, based on the sensor information shared via V2X communications, two or more autonomous vehicle in the group of autonomous vehicles may coordinate one or more actions, such as avoiding the object or maintaining a pre-determined distance between the two or more autonomous vehicles.

Sidelink (SL) communication is another example of D2D communication that enables a user equipment (UE) to communicate with another UE without tunneling through a base station and/or a core network. Sidelink communications can be communicated over a physical sidelink control channel (PSCCH) and a physical sidelink shared channel (PSSCH). The PSCCH and PSSCH are similar to a physical downlink control channel (PDCCH) and a physical downlink shared channel (PDSCH) in downlink (DL) communications between a base station and a UE. For instance, the PSCCH may carry sidelink control information (SCI) and the PSCCH may carry sidelink data (for example, user data). Each PSCCH is associated with a corresponding PSSCH, where SCI in a PSCCH may carry reservation and/or scheduling information for a sidelink data transmission in the associated PSSCH. Use cases for sidelink communications may include, among others, V2X, industrial Internet of Things (IoT) (IIoT), and/or NR-lite.

In some wireless communication systems, a network node (for example, a base station, a UE, or a sidelink UE) may communicate with a group of UEs, via one or more multicast messages, or a specific UE, via one or more unicast messages. The specific UE may be one UE of the group of UEs or may be excluded from the group of UEs. The one or more unicast messages may be used for point-to-point services, such as, for example, voice calling, text messaging, or video calling. Additionally, the one or more multicast messages may be used for point-to-multipoint services, such as, for example, event-related multimedia broadcasts. In some examples, the network node may intend to transmit a unicast message to the specific UE in the group of UEs while also intending to transmit a multicast message to the group of UEs. In conventional systems, the network node separately transmits the unicast message and the multicast message, thereby increasing a number of transmissions from the network node. For example, the network node may first transmit the unicast message to the specific UE and then transmit the multicast message to the group of UEs, or vice versa. The increase in the number of transmissions from the network node may increase network overhead and reduce spectral efficiency.

Various aspects of the present disclosure generally relate to multiplexing messages, and specifically to multiplexing, at a first UE, a unicast message for a second UE with a multicast message for a group of UEs that includes the second UE. In some examples, the unicast message may be multiplexed on one or more resources of a resource set associated with transmitting the multicast message. In some examples, the first UE may receive, from a network node, a message configuring the first UE to allocate the one or more resources from the resource set. In such examples, the resource set may be allocated via a sidelink mode 1 message or a semi-persistent scheduling (SPS) grant received, at the first UE, from the network node. After multiplexing the unicast message with the multicast message, the first UE may then transmit the multiplexed unicast and multicast messages to the group of UEs. The unicast message may include a destination identifier (ID) and a source ID. Therefore, each UE in the group of UEs may ignore the unicast message if an ID of the UE does not match the destination ID included in the unicast message. In some examples, the multiplexed unicast and multicast messages may be transmitted via one or more sidelink channels. In other examples, a network node, such as a base station, may multiplex unicast and multicast messages and transmit the multiplexed unicast and multicast messages via one or more downlink channels to the group of UEs, such as one or more downlink channels associated with a network access link (e.g., Uu-interface).

In examples in which the first UE transmits the multiplexed unicast and multicast messages to the group of UEs, the first UE may then receive, from each UE in the group of UEs, one or more hybrid automatic repeat request (HARQ) feedback messages based on transmitting the multiplexed unicast and multicast messages. In some examples, the first UE may receive, from the second UE, a first HARQ feedback message associated with the unicast message and a second HARQ feedback message associated with the multicast message. The first HARQ feedback and the second HARQ feedback may be separately received in different HARQ feedback messages or bundled in a single HARQ feedback message. Additionally, the first UE may receive, from each of the other UEs in the group of UEs, a single respective HARQ feedback message associated with the multicast message because the unicast message was only intended for the second UE. In some examples, the first UE may receive the one or more HARQ feedback messages via a physical sidelink feedback channel (PSFCH).

Particular aspects of the subject matter described in this disclosure may be implemented to realize one or more of the following potential advantages. In some examples, the described techniques may reduce a number of transmissions from a transmitting UE by multiplexing the unicast message for the second UE with the multicast message for the group of UEs that includes the second UE so as to reduce network overhead. The reduced network overhead may improve overall network quality.

Certain UEs104may communicate with each other using device-to-device (D2D) communications link158. The D2D communications link158may use the DL/UL WWAN spectrum. The D2D communications link158may use one or more sidelink channels, such as a physical sidelink broadcast channel (PSBCH), a physical sidelink discovery channel (PSDCH), a physical sidelink shared channel (PSSCH), and a physical sidelink control channel (PSCCH). D2D communications may be through a variety of wireless D2D communications systems, such as FlashLinQ, WiMedia, Bluetooth, ZigBee, Wi-Fi based on the IEEE 802.11 standard, LTE, or NR.

A base station102, whether a small cell102′ or a large cell (for example, macro base station), may include a NR BS, a Node B, a 5G node B, an eNB, a gNodeB (gNB), an access point, a transmit and receive point (TRP), a network node, a network entity, and/or the like. A base station can be implemented as an aggregated base station, as a disaggregated base station, an integrated access and backhaul (IAB) node, a relay node, a sidelink node, etc. The base station can be implemented in an aggregated or monolithic base station architecture, or alternatively, in a disaggregated base station architecture, and may include one or more of a central unit (CU), a distributed unit (DU), a radio unit (RU), a near-real time (near-RT) RAN intelligent controller (RIC), or a non-real time (non-RT) RIC. Some base stations, such as gNB180may operate in a traditional sub 6 GHz spectrum, in millimeter wave (mmWave) frequencies, and/or near mmWave frequencies in communication with the UE104. When the gNB180operates in mmWave or near mmWave frequencies, the gNB180may be referred to as an mmWave base station. Extremely high frequency (EHF) is part of the radio frequency (RF) in the electromagnetic spectrum. EHF has a range of 30 GHz to 300 GHz and a wavelength between 1 millimeter and 10 millimeters. Radio waves in the band may be referred to as a millimeter wave. Near mmWave may extend down to a frequency of 3 GHz with a wavelength of 100 millimeters. The super high frequency (SHF) band extends between 3 GHz and 30 GHz, also referred to as centimeter wave. Communications using the mmWave/near mmWave radio frequency band (for example, 3 GHz-300 GHz) has extremely high path loss and a short range. The mmWave base station180may utilize beamforming182with the UE104to compensate for the extremely high path loss and short range.

Referring again toFIG.1, the UE104may include a multiplexing component198configured to perform the operations disclosed with reference toFIGS.9and10.

Although the following description may be focused on 5G NR, it may be applicable to other similar areas, such as LTE, LTE-A, CDMA, GSM, and other wireless technologies.

FIG.2shows a block diagram of a design200of the base station102and UE104, which may be one of the base stations and one of the UEs inFIG.1, respectively. The base station102may be equipped with T antennas234athrough234t, and UE104may be equipped with R antennas252athrough252r, where in general T≥1 and R≥1.

At the base station102, 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 (for example, 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. Decreasing the MCS lowers throughput but increases reliability of the transmission. The transmit processor220may also process system information (for example, for semi-static resource partitioning information (SRPI) and/or the like) and control information (for example, CQI requests, grants, upper layer signaling, and/or the like) and provide overhead symbols and control symbols. The transmit processor220may also generate reference symbols for reference signals (for example, the cell-specific reference signal (CRS)) and synchronization signals (for example, the primary synchronization signal (PSS) and secondary synchronization signal (SSS)). A transmit (TX) multiple-input multiple-output (MIMO) processor230may perform spatial processing (for example, 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 (for example, for orthogonal frequency division multiplexing (OFDM) and/or the like) to obtain an output sample stream. Each modulator232may further process (for example, 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 the UE104, antennas252athrough252rmay receive the downlink signals from the base station102and/or other base stations and may provide received signals to demodulators (DEMODs)254athrough254r, respectively. Each demodulator254may condition (for example, filter, amplify, downconvert, and digitize) a received signal to obtain input samples. Each demodulator254may further process the input samples (for example, 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 (for example, demodulate and decode) the detected symbols, provide decoded data for the UE104to 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 the UE104may be included in a housing.

On the uplink, at the UE104, a transmit processor264may receive and process data from a data source262and control information (for example, for reports comprising RSRP, RSSI, RSRQ, CQI, and/or the like) from the controller/processor280. Transmit processor264may also generate reference symbols for one or more reference signals. The symbols from the transmit processor264may be precoded by a TX MIMO processor266if applicable, further processed by modulators254athrough254r(for example, for discrete Fourier transform spread (DFT-s)-OFDM, CP-OFDM, and/or the like), and transmitted to the base station102. At the base station102, the uplink signals from the UE104and other UEs may be received by the antennas234, processed by the demodulators254, detected by a MIMO detector236if applicable, and further processed by a receive processor238to obtain decoded data and control information sent by the UE104. The receive processor238may provide the decoded data to a data sink239and the decoded control information to a controller/processor240. The base station102may include communications unit244and communicate to the core network130via the communications unit244. The core network130may include a communications unit294, a controller/processor290, and a memory292.

The controller/processor240of the base station102, the controller/processor280of the UE104, and/or any other component(s) ofFIG.2may perform one or more techniques associated with multiplexing a unicast message with a multicast message as described in more detail elsewhere. For example, the controller/processor240of the base station102, the controller/processor280of the UE104, and/or any other component(s) ofFIG.2may perform or direct operations of, for example, the processes ofFIGS.9and10and/or other processes as described. Memories242and282may store data and program codes for the base station102and UE104, respectively. A scheduler246may schedule UEs for data transmission on the downlink and/or uplink.

FIG.3shows a diagram illustrating an example disaggregated base station300architecture. The disaggregated base station300architecture may include one or more central units (CUs)310that can communicate directly with a core network320via a backhaul link, or indirectly with the core network320through one or more disaggregated base station units (such as a near-real time (near-RT) RAN intelligent controller (RIC)325via an E2 link, or a non-real time (non-RT) RIC315associated with a service management and orchestration (SMO) framework305, or both). A CU310may communicate with one or more distributed units (DUs)330via respective midhaul links, such as an F1 interface. The DUs330may communicate with one or more radio units (RUs)340via respective fronthaul links. The RUs340may communicate with respective UEs104via one or more radio frequency (RF) access links. In some implementations, the UE104may be simultaneously served by multiple RUs340.

Lower-layer functionality can be implemented by one or more RUs340. In some deployments, an RU340, controlled by a DU330, may correspond to a logical node that hosts RF processing functions, or low-PHY layer functions (such as performing fast Fourier transform (FFT), inverse FFT (iFFT), digital beamforming, physical random access channel (PRACH) extraction and filtering, or the like), or both, based at least in part on the functional split, such as a lower layer functional split. In such an architecture, the RU(s)340can be implemented to handle over the air (OTA) communication with one or more UEs104. In some implementations, real-time and non-real-time aspects of control and user plane communication with the RU(s)340can be controlled by the corresponding DU330. In some scenarios, this configuration can enable the DU(s)330and the CU310to be implemented in a cloud-based RAN architecture, such as a vRAN architecture.

FIG.4is a diagram of a device-to-device (D2D) communications system400, including V2X communications, in accordance with various aspects of the present disclosure. For example, the D2D communications system400may include V2X communications, (for example, a first UE450communicating with a second UE451). In some aspects, one or both of the first UE450or the second UE451may be configured to communicate in a one or both of licensed radio frequency spectrum or a shared radio frequency spectrum. The UEs450,451, and452may be examples of a UE104described with reference toFIGS.1,2, and3. The shared radio frequency spectrum may be unlicensed, and therefore multiple different technologies may use the shared radio frequency spectrum for communications, including new radio (NR), LTE, LTE-Advanced, licensed assisted access (LAA), dedicated short range communications (DSRC), MuLTEFire, 4G, and the like. The foregoing list of technologies is to be regarded as illustrative, and is not meant to be exhaustive.

The D2D communications system400may use NR radio access technology. Of course, other radio access technologies, such as LTE radio access technology, may be used. In D2D communications (for example, V2X communications or vehicle-to-vehicle (V2V) communications), the UEs450,451may be on networks of different mobile network operators (MNOs). Each of the networks may operate in its own radio frequency spectrum. For example, the air interface to a first UE450(for example, Uu interface) may be on one or more frequency bands different from the air interface of the second UE451. The first UE450and the second UE451may communicate via a sidelink component carrier, for example, via the PC5 interface. In some examples, the MNOs may schedule sidelink communications between or among the UEs450,451in licensed radio frequency spectrum and/or a shared radio frequency spectrum (for example, 5 GHz radio spectrum bands).

The shared radio frequency spectrum may be unlicensed, and therefore different technologies may use the shared radio frequency spectrum for communications. In some aspects, a D2D communications (for example, sidelink communications) between or among UEs450,451is not scheduled by MNOs. The D2D communications system400may further include a third UE452.

The third UE452may operate on the first network410(for example, of the first MNO) or another network, for example. The third UE452may be in D2D communications with the first UE450and/or second UE451. The first base station420(for example, gNB) may communicate with the third UE452via a downlink (DL) carrier432and/or an uplink (UL) carrier442. The base stations420and421may be examples of a base station102described with reference toFIGS.1and2, or a CU310, DU330, or RU340described with reference toFIG.3. The DL communications may be use various DL resources (for example, the DL subframes and/or the DL channels). The UL communications may be performed via the UL carrier442using various UL resources (for example, the UL subframes and the UL channels).

The first network410operates in a first frequency spectrum and includes the first base station420(for example, gNB) communicating at least with the first UE450. The first base station420(for example, gNB) may communicate with the first UE450via a DL carrier430and/or an UL carrier440. The DL communications may be use various DL resources (for example, the DL subframes and/or the DL channels). The UL communications may be performed via the UL carrier440using various UL resources (for example, the UL subframes and the UL channels).

In some aspects, the second UE451may be on a different network from the first UE450. In some aspects, the second UE451may be on a second network411(for example, of the second MNO). The second network411may operate in a second frequency spectrum (for example, a second frequency spectrum different from the first frequency spectrum) and may include the second base station421(for example, gNB) communicating with the second UE451.

The second base station421may communicate with the second UE451via a DL carrier431and an UL carrier441. The DL communications are performed via the DL carrier431using various DL resources (for example, the DL subframes (FIG.2A) and/or the DL channels (FIG.2B)). The UL communications are performed via the UL carrier441using various UL resources (for example, the UL subframes (FIG.2C) and/or the UL channels (FIG.2D)).

In conventional systems, the first base station420and/or the second base station421assign resources to the UEs for device-to-device (D2D) communications (for example, V2X communications and/or V2V communications). For example, the resources may be a pool of UL resources, both orthogonal (for example, one or more frequency division multiplexing (FDM) channels) and non-orthogonal (for example, code division multiplexing (CDM)/resource spread multiple access (RSMA) in each channel). The first base station420and/or the second base station421may configure the resources via the PDCCH (for example, faster approach) or RRC (for example, slower approach).

In some systems, each UE450,451autonomously selects resources for D2D communications. For example, each UE450,451may sense and analyze channel occupation during the sensing window. The UEs450,451may use the sensing information to select resources from the sensing window. As discussed, one UE451may assist another UE450in performing resource selection. The UE451providing assistance may be referred to as the receiver UE or partner UE, which may potentially notify the transmitter UE450. The transmitter UE450may transmit information to the receiving UE451via sidelink communications.

The D2D communications (for example, V2X communications and/or V2V communications) may be carried out via one or more sidelink carriers470,480. The one or more sidelink carriers470,480may include one or more channels, such as a physical sidelink broadcast channel (PSBCH), a physical sidelink discovery channel (PSDCH), a physical sidelink shared channel (PSSCH), and a physical sidelink control channel (PSCCH), for example.

In some examples, the sidelink carriers470,480may operate using the PC5 interface. The first UE450may transmit to one or more (for example, multiple) devices, including to the second UE451via the first sidelink carrier470. The second UE451may transmit to one or more (for example, multiple) devices, including to the first UE450via the second sidelink carrier480.

In some aspects, the UL carrier440and the first sidelink carrier470may be aggregated to increase bandwidth. In some aspects, the first sidelink carrier470and/or the second sidelink carrier480may share the first frequency spectrum (with the first network410) and/or share the second frequency spectrum (with the second network411). In some aspects, the sidelink carriers470,480may operate in an unlicensed/shared radio frequency spectrum.

In some aspects, sidelink communications on a sidelink carrier may occur between the first UE450and the second UE451. In an aspect, the first UE450may perform sidelink communications with one or more (for example, multiple) devices, including the second UE451via the first sidelink carrier470. For example, the first UE450may transmit a broadcast transmission via the first sidelink carrier470to the multiple devices (for example, the second and third UEs451,452). The second UE451(for example, among other UEs) may receive such broadcast transmission. Additionally or alternatively, the first UE450may transmit a multicast transmission via the first sidelink carrier470to the multiple devices (for example, the second and third UEs451,452). The second UE451and/or the third UE452(for example, among other UEs) may receive such multicast transmission. The multicast transmissions may be connectionless or connection-oriented. A multicast transmission may also be referred to as a groupcast transmission.

Furthermore, the first UE450may transmit a unicast transmission via the first sidelink carrier470to a device, such as the second UE451. The second UE451(for example, among other UEs) may receive such unicast transmission. Additionally or alternatively, the second UE451may perform sidelink communications with one or more (for example, multiple) devices, including the first UE450via the second sidelink carrier480. For example, the second UE451may transmit a broadcast transmission via the second sidelink carrier480to the multiple devices. The first UE450(for example, among other UEs) may receive such broadcast transmission.

In another example, the second UE451may transmit a multicast transmission via the second sidelink carrier480to the multiple devices (for example, the first and third UEs450,452). The first UE450and/or the third UE452(for example, among other UEs) may receive such multicast transmission. Further, the second UE451may transmit a unicast transmission via the second sidelink carrier480to a device, such as the first UE450. The first UE450(for example, among other UEs) may receive such unicast transmission. The third UE452may communicate in a similar manner.

In some aspects, for example, such sidelink communications on a sidelink carrier between the first UE450and the second UE451may occur without having MNOs allocating resources (for example, one or more portions of a resource block (RB), slot, frequency band, and/or channel associated with a sidelink carrier470,480) for such communications and/or without scheduling such communications. Sidelink communications may include traffic communications (for example, data communications, control communications, paging communications and/or system information communications). Further, sidelink communications may include sidelink feedback communications associated with traffic communications (for example, a transmission of feedback information for previously-received traffic communications). Sidelink communications may employ at least one sidelink communications structure having at least one feedback symbol. The feedback symbol of the sidelink communications structure may allot for any sidelink feedback information that may be communicated in the device-to-device (D2D) communications system400between devices (for example, a first UE450, a second UE451, and/or a third UE452). As discussed, a UE may be a vehicle (for example, UE450,451), a mobile device (for example, 452), or another type of device. In some cases, a UE may be a special UE, such as a roadside unit (RSU).

FIG.5illustrates an example of a vehicle-to-everything (V2X) system with a roadside unit (RSU), according to aspects of the present disclosure. As shown inFIG.5, V2X system500includes a transmitter UE504transmits data to an RSU510and a receiving UE502via sidelink transmissions512. The UEs502,504, and506may be examples of a UE104described with reference toFIGS.1,2, and3. Additionally, or alternatively, the RSU510may transmit data to the transmitter UE504via a sidelink transmission512. The RSU510may forward data received from the transmitter UE504to a cellular network base station (for example, gNB)102via an UL transmission514. The gNB508may transmit the data received from the RSU510to other UEs506via a DL transmission516. The RSU510may be incorporated with traffic infrastructure (for example, traffic light, light pole, etc.) For example, as shown inFIG.5, the RSU510is a traffic signal positioned at a side of a road520. Additionally or alternatively, RSUs510may be stand-alone units.

FIG.6is a graph illustrating a sidelink (SL) communications scheme, in accordance with various aspects of the present disclosure. A scheme600may be employed by UEs such as the UEs104in a network such as the network100. In FIG.6, the x-axis represents time and the y-axis represents frequency. The CV2X channels may be for 3GPP Release 16 and beyond.

In the scheme600, a shared radio frequency band601is partitioned into multiple subchannels or frequency subbands602(shown as602S0,602S1,602S2) in frequency and multiple sidelink frames604(shown as604a,604b,604c,604d) in time for sidelink communications. The frequency band601may be at any suitable frequencies. The frequency band601may have any suitable bandwidth (BW) and may be partitioned into any suitable number of frequency subbands602. The number of frequency subbands602can be dependent on the sidelink communications BW requirement.

Each sidelink frame604includes a sidelink resource606in each frequency subband602. A legend605indicates the types of sidelink channels within a sidelink resource606. In some instances, a frequency gap or guard band may be specified between adjacent frequency subbands602, for example, to mitigate adjacent band interference. The sidelink resource606may have a substantially similar structure as an NR sidelink resource. For instance, the sidelink resource606may include a number of subcarriers or RBs in frequency and a number of symbols in time. In some instances, the sidelink resource606may have a duration between about one millisecond (ms) to about 20 ms. Each sidelink resource606may include a PSCCH610and a PSSCH620. The PSCCH610and the PSSCH620can be multiplexed in time and/or frequency. The PSCCH610may be for part one of a control channel (CCH), with the second part arriving as a part of the shared channel allocation. In the example ofFIG.6, for each sidelink resource606, the PSCCH610is located during the beginning symbol(s) of the sidelink resource606and occupies a portion of a corresponding frequency subband602, and the PSSCH620occupies the remaining time-frequency resources in the sidelink resource606. In some instances, a sidelink resource606may also include a physical sidelink feedback channel (PSFCH), for example, located during the ending symbol(s) of the sidelink resource606. In general, a PSCCH610, a PSSCH620, and/or a PSFCH may be multiplexed within a sidelink resource606.

The PSCCH610may carry SCI660and/or sidelink data. The sidelink data can be of various forms and types depending on the sidelink application. For instance, when the sidelink application is a V2X application, the sidelink data may carry V2X data (for example, vehicle location information, traveling speed and/or direction, vehicle sensing measurements, etc.). Alternatively, when the sidelink application is an IIoT application, the sidelink data may carry IIoT data (for example, sensor measurements, device measurements, temperature readings, etc.). The PSFCH can be used for carrying feedback information, for example, hybrid automatic repeat request (HARQ) acknowledgment/negative acknowledgment (ACK/NACK) for sidelink data received in an earlier sidelink resource606.

In an NR sidelink frame structure, the sidelink frames604in a resource pool608may be contiguous in time. A sidelink UE (for example, the UEs104) may include, in SCI660, a reservation for a sidelink resource606in a later sidelink frame604. Thus, another sidelink UE (for example, a UE in the same NR-U sidelink system) may perform SCI sensing in the resource pool608to determine whether a sidelink resource606is available or occupied. For instance, if the sidelink UE detected SCI indicating a reservation for a sidelink resource606, the sidelink UE may refrain from transmitting in the reserved sidelink resource606. If the sidelink UE determines that there is no reservation detected for a sidelink resource606, the sidelink UE may transmit in the sidelink resource606. As such, SCI sensing can assist a UE in identifying a target frequency subband602to reserve for sidelink communications and to avoid intra-system collision with another sidelink UE in the NR sidelink system. In some aspects, the UE may be configured with a sensing window for SCI sensing or monitoring to reduce intra-system collision.

In some aspects, the sidelink UE may be configured with a frequency hopping pattern. In this regard, the sidelink UE may hop from one frequency subband602in one sidelink frame604to another frequency subband602in another sidelink frame604. In the illustrated example ofFIG.6, during the sidelink frame604a, the sidelink UE transmits SCI660in the sidelink resource606located in the frequency subband602S2to reserve a sidelink resource606in a next sidelink frame604blocated at the frequency subband602S1. Similarly, during the sidelink frame604b, the sidelink UE transmits SCI662in the sidelink resource606located in the frequency subband602S1to reserve a sidelink resource606in a next sidelink frame604clocated at the frequency subband602S1. During the sidelink frame604c, the sidelink UE transmits SCI664in the sidelink resource606located in the frequency subband602S1to reserve a sidelink resource606in a next sidelink frame604dlocated at the frequency subband602S0. During the sidelink frame604d, the sidelink UE transmits SCI668in the sidelink resource606located in the frequency subband602S0. The SCI668may reserve a sidelink resource606in a later sidelink frame604.

The SCI can also indicate scheduling information and/or a destination identifier (ID) identifying a target receiving sidelink UE for the next sidelink resource606. Thus, a sidelink UE may monitor SCI transmitted by other sidelink UEs. Upon detecting SCI in a sidelink resource606, the sidelink UE may determine whether the sidelink UE is the target receiver based on the destination ID. If the sidelink UE is the target receiver, the sidelink UE may proceed to receive and decode the sidelink data indicated by the SCI. In some aspects, multiple sidelink UEs may simultaneously communicate sidelink data in a sidelink frame604in different frequency subband (for example, via frequency division multiplexing (FDM)). For instance, in the sidelink frame604b, one pair of sidelink UEs may communicate sidelink data using a sidelink resource606in the frequency subband602S2while another pair of sidelink UEs may communicate sidelink data using a sidelink resource606in the frequency subband602S1.

In some aspects, the scheme600is used for synchronous sidelink communications. That is, the sidelink UEs may be synchronized in time and are aligned in terms of symbol boundary, sidelink resource boundary (for example, the starting time of sidelink frames604). The sidelink UEs may perform synchronization in a variety of forms, for example, based on sidelink synchronization signal blocks (SSBs) received from a sidelink UE and/or NR-U SSBs received from a base station (for example, the base station102) while in-coverage of the base station. In some aspects, the sidelink UE may be preconfigured with the resource pool608in the frequency band601, for example, while in coverage of a serving base station. The resource pool608may include a plurality of sidelink resources606. The base station can configure the sidelink UE with a resource pool configuration indicating resources in the frequency band601and/or the subbands602and/or timing information associated with the sidelink frames604. In some aspects, the scheme600includes mode-2 RRA (for example, supporting autonomous radio resource allocation (RRA) that can be used for out-of-coverage sidelink UEs or partial-coverage sidelink UEs).

In some wireless communication systems, a network node (for example, a base station, a UE, or a sidelink UE) may communicate with a group of UEs, via one or more multicast messages, or a specific UE, via one or more unicast messages. The specific UE may be one UE of the group of UEs or may be excluded from the group of UEs. The one or more unicast messages may be used for point-to-point services, such as, for example, voice calling, text messaging, or video calling. Additionally, the one or more multicast messages may be used for point-to-multipoint services, such as, for example, event-related multimedia broadcasts. In some examples, the network node may intend to transmit a unicast message to the specific UE in the group of UEs while also intending to transmit a multicast message to the group of UEs. The unicast message may include a destination ID and a source ID, and the multicast message may include a destination group ID and the source ID. Any UE configured to receive a destination group ID (for example, destination group Layer 2 ID) may receive the multicast transmission, whether it is within or beyond a minimum communication range specified by upper layers.

In conventional systems, the network node separately transmits the unicast message and the multicast message, thereby increasing a number of transmissions from the network node. For example, the network node may first transmit the unicast message to the specific UE and then transmit the multicast message to the group of UEs, or vice versa. The increase in the number of transmissions from the network node may increase network overhead and reduce spectral efficiency.

Various aspects of the present disclosure generally relate to multiplexing messages, and specifically to multiplexing, at a first UE, a unicast message for a second UE with a multicast message for a group of UEs that includes the second UE.FIG.7Ais a block diagram illustrating an example700of multiplexing a unicast message with a multicast message, in accordance with various aspects of the present disclosure. As shown in the example700ofFIG.7A, a first UE702may communicate with a group of UEs that includes a second UE704and a third UE706. In some examples, a network node, such as a base station102described with reference toFIGS.1and2, or a CU310, DU330, or RU340described with reference toFIG.3may communicated with the group of UEs. The UEs702,704, and706may be examples of a UE104as described with reference toFIGS.1-3, a UE450,451, or452as described with reference toFIG.4, or a UE502,504, or506as described with reference toFIG.5. In some examples, the first UE702may include a unicast transmission module708, a multicast transmission module710, and a multiplexer712. In such examples, the unicast transmission module708may encode a unicast message w1for the second UE704and the multicast transmission module710may encode a multicast message wgfor the group of UEs704and706. Specifically, a destination ID in the unicast message w1may correspond to a destination ID of the second UE704. Additionally, a group ID in the multicast message wgmay correspond to a group ID of the group of UEs704and706. The multiplexer712may multiplex the unicast message w1with the multicast message wgto generate a multiplexed message w1wq.

In some examples, the unicast message w1may be multiplexed on one or more resources of a resource set associated with transmitting the multicast message wg. The multiplexing may be configured, by a network node, on a per resource set basis. For example, the network node may indicate the multiplexing is enabled for one resource set and disabled for another resource set. The resource set may be allocated via a sidelink mode 1 message or an SPS grant. Additionally, or alternatively, the multiplexing may be performed when a multiplexing condition is satisfied. In some examples, the multiplexing condition may be satisfied if the unicast message is delay stringent. In other examples, the multiplexing condition may be satisfied based on the first UE702satisfying a power requirement. For example, the first UE702may perform the multiplexing operation based on satisfying a power requirement associated with the multicast message wgor satisfying a power requirement associated with the unicast message w1. In other examples, the multiplexing condition may be satisfied based on a priority of one or both of the multicast message wgor the unicast message w1. For example, the first UE702may multiplex the multicast message wgwith the unicast message w1regardless of the priority of each message. In another example, the first UE702may multiplex the multicast message wgwith the unicast message w1if the priority of both messages is a low priority. In still another example, if the priority of the multicast message wgis different than the priority of the unicast message w1the first UE702may follow RRC configured criteria.

As shown in the example700ofFIG.7A, the first UE702may transmit the multiplexed message w1wgto each UE in the group of UEs704and706. In some examples, each UE in the group of UEs704and706may perform successive cancellation based on a power allocated to a signal associated with each of the unicast message w1and the multicast message wg. In the example ofFIG.7A, the third UE706may ignore the unicast message w1and only decode the multicast message w9because the destination ID of the unicast message w1may not match an ID of the third UE706(for example, the destination ID of the unicast message w1corresponds to the ID of the second UE704). Additionally, the second UE704may decode both the unicast message w1and the multicast message wg. Each UE of the group of UEs704and706may transmit one or more hybrid automatic repeat request (HARQ) feedback messages based on receiving the multiplexed message w1wg. The third UE706may transmit a HARQ feedback message associated with the multicast message wg. Additionally, the second UE704may transmit a first HARQ feedback message associated with the multicast message wgand a second HARQ feedback message associated with the unicast message w1. For ease of explanation, the first HARQ feedback message may be referred to as the multicast feedback message and the second HARQ feedback message may be referred to as the unicast feedback message. In some examples, the second UE704may separately transmit the unicast feedback message and the multicast feedback message. In other examples, the second UE704may transmit a single HARQ feedback message including the multicast feedback bundled with the unicast feedback.

In some examples, the one or more HARQ feedback messages may be transmitted via a physical sidelink feedback channel (PSFCH). In such examples, HARQ feedback is an example of sidelink feedback. The first UE702may report the sidelink feedback to the network node via the physical uplink control channel (PUCCH) using PUCCH resources assigned by the network node. The sidelink feedback from the first UE702reports a negative acknowledgment (NACK) if the first UE702did not transmit on the PSSCH or receive feedback on the PSFCH due to intra-UE prioritization. Alternatively, sidelink feedback from the first UE702reports an acknowledgment (ACK) if the first UE702receives an ACK from each UE in the group of UEs704and706based on transmitting the multiplexed message w1wg.

In some examples, different resources may be allocated for the unicast feedback message and the multicast feedback message. In some other examples, the same resources may be used for the unicast feedback message and the multicast feedback message. In some such examples, each HARQ feedback message may be associated with a different cyclic-shift (CS) (for example, for PSFCH format 0), different orthogonal cover codes (OCCs), or different power levels. In other such examples, each HARQ feedback message may be associated with a different time offset, such as a different time offset for Kl HARQ timing, configured via downlink control information (DCI). The Kl HARQ timing may be indicated via the DCI, and the offset may be preconfigured via layer one (L1), layer two (L2), or layer three (L3) signaling.

As discussed, in some examples, the HARQ feedback may be transmitted via the PSFCH. In such examples, the second UE704transmitting the unicast feedback message and the multicast feedback message may use the same resource block for each feedback message when sending a NACK. For example, the second UE704may use the same resource block with a different cyclic shift or a different power level for each feedback message. In some other examples, the second UE704may use a different resource block for each feedback message. The resource block for the unicast feedback message may be based on an offset defined for the second UE704by the network node. Alternatively, the second UE704may use its own ID. In some other examples, each feedback message may use a resource block corresponding to the unicast message w1, and a different cyclic shift may be applied to each feedback message. In some other examples, a new resource block may be defined for the feedback messages. The new resource block may be defined based on new rules associated with using the resource block corresponding to the unicast message w1, in which a different cyclic shift or power level may be applied to each feedback message. In some other examples, a new set of continuous resource blocks may be defined. In such examples, a new PSFCH format may be used (for example, a higher order format that may include more than one bit) to send the unicast feedback message and the multicast feedback message. In some other examples, a same physical resource block may be used across two different PSFCH resources (for example, two different slots) based on a time offset configured via L1, L2, or L3 signaling.

FIG.7Bis a timing diagram illustrating an example of transmitting a multiplexed unicast message and multicast message, in accordance with various aspects of the present disclosure. In the example750ofFIG.7B, the first UE702may communicate with a network node720and a group of UEs that includes the second UE704and the third UE706. The network node720may be an example of a base station102as described with reference toFIG.1, a CU310, DU330, or RU340as described with reference toFIG.3, or a base station420or421as described with reference toFIG.4. In the example750, the first UE702generates a unicast message intended for the second UE704and a multicast message intended for the group of UEs704and706. The multicast message may be associated with a first priority and the unicast message may be associated with a second priority. Aspects of the present disclosure are not limited to the multicast message. Other types of messages specified for a group of UEs, such as a groupcast message or a broadcast message, may be multiplexed with the unicast message.

As shown in the example ofFIG.7B, at time t1, the first UE702may receive a first message, from the network node720, allocating a resource set for the multicast transmission. In some examples, the resource set may be allocated via an SPS grant. In other examples, the resource set may be allocated via a sidelink mode 1 message, such that the resource set is an example of a resource pool and resources in the resource set are sidelink resources. In an optional implementation, at time t2, the first UE702may receive a second message, from the network node720, configuring the first UE702to allocate one or more resources, from the resource set, to the unicast message.

Additionally, or alternatively, in an optional implementation, at time t3, the first UE702may receive an RRC message configuring the first UE702to transmit a message (for example, the unicast message, the multicast message, or the multiplexed unicast and multicast messages) based on a priority. In some examples, the RRC message may configure the first UE702to transmit, to the second UE704, the unicast message, or to transmit, to the group of UEs704and706, the multicast message, based on one of the first priority or the second priority satisfying a priority condition. In some examples, the priority condition may be satisfied based on one of the first priority or the second priority having a highest priority among the first priority and the second priority. In some examples, the RRC message may configure the first UE702to transmit the multiplexed unicast and multicast messages based on the first priority being different than the second priority.

At time t4, the first UE702may determine if a multiplexing condition is satisfied. In some examples, the multiplexing condition may be satisfied if the second message (time t2) configures the first UE702to allocate one or more resources, from the resource set, to the unicast message. Additionally, or alternatively, the multiplexing condition may be satisfied if the unicast message is associated with a delay stringent packet.

Additionally, or alternatively, in some examples, the multiplexing condition may be satisfied based on the first priority and the second priority being a low priority. In other examples, the first priority may be different than the second priority. In such examples, the multiplexing condition may be satisfied based on the first UE702satisfying a power condition associated with a message (for example, unicast message or multicast message) having a highest priority among the first priority and the second priority. For example, the multiplexed message may be satisfied based on the first UE702satisfying a power condition associated with either: the multicast message based on the first priority being higher than the second priority; or the unicast message based on the second priority being higher than the first priority. In some other examples, the multiplexing condition may not be satisfied if the first priority is different than the second priority. In some such examples, the first UE702may only transmit the message (for example, unicast message or multicast message) having a highest priority among the first priority and the second priority. In other such examples, the first UE702transmits the message (for example, unicast message or multicast message) based on the configuration indicated by the RRC message received at time t3.

In the example750, it is assumed the multiplexing condition is satisfied. In an optional implementation, based on satisfying the multiplexing condition, the first UE702may transmit, at time t5, a third message, such as an RRC message, MAC-CE, or SCI, configuring the group of UEs704and706to enable, or disable, reception of the multiplexed unicast and multicast messages. In some such examples, the SCI may enable, or disable, the reception of the multiplexed unicast and multicast messages at the group of UEs704and706for certain sidelink transmission. The SCI may also indicate a configuration of the unicast message and the multicast message (for example, groupcast message).

As shown inFIG.7B, at time t6, the first UE702may multiplex the unicast message with the multicast message based on satisfying the multiplexing condition. The unicast message may be multiplexed on one or more resources of the resource set associated with transmitting the multicast message. At time t7, the first UE702transmits, to the group of UEs704and706, the multiplexed unicast and multicast messages. At time t8, the first UE702, receives from each UE in the group of UEs704and706, one or more HARQ feedback messages based on transmitting the multiplexed unicast and multicast messages. In some examples, the third UE706may only transmit a HARQ message associated with the multicast message. As discussed with respect to the example ofFIG.7A, the third UE706may ignore the unicast message because the destination ID included in the unicast message may not match the ID of the third UE706. The second UE704may transmit a first HARQ feedback message associated with the unicast message and a second HARQ feedback message associated with the multicast message. The first HARQ feedback message and the second HARQ feedback message may be separately transmitted. Alternatively, the second UE704may transmit a single HARQ feedback message including first HARQ feedback associated with the unicast message bundled with second HARQ feedback associated with the multicast message. The one or more HARQ feedback messages may be received via a physical sidelink feedback channel (PSFCH).

FIG.8is a block diagram illustrating an example wireless communication device800that supports multiplexing a unicast message and a multicast message, in accordance with some aspects of the present disclosure. The device800may be an example of aspects of a UE704described with reference toFIGS.7A and7B. The wireless communication device800may include a receiver810, a communications manager808, a transmitter820, a multiplexing component830, a feedback component840, and a priority component850which may be in communication with one another (for example, via one or more buses). In some examples, the wireless communication device800is configured to perform operations, including operations of the process900described below with reference toFIG.9.

In some examples, the wireless communication device800can include a chip, chipset, package, or device that includes at least one processor and at least one modem (for example, a 5G modem or other cellular modem). In some examples, the communications manager808, or its sub-components, may be separate and distinct components. In some examples, at least some components of the communications manager808are implemented at least in part as software stored in a memory. For example, portions of one or more of the components of the communications manager808can be implemented as non-transitory code executable by the processor to perform the functions or operations of the respective component.

The receiver810may receive one or more of reference signals (for example, periodically configured channel state information reference signals (CSI-RSs), aperiodically configured CSI-RSs, or multi-beam-specific reference signals), synchronization signals (for example, synchronization signal blocks (SSBs)), control information and data information, such as in the form of packets, from one or more other wireless communication devices via various channels including control channels (for example, a physical downlink control channel (PDCCH), physical uplink control channel (PUCCH), or physical sidelink control channel PSCCH) and data channels (for example, a physical downlink shared channel (PDSCH), PSSCH, a physical uplink shared channel (PUSCH)). The other wireless communication devices may include, but are not limited to, a network node720described with reference toFIG.7B.

The received information may be passed on to other components of the device800. The receiver810may be an example of aspects of the receive processor256described with reference toFIG.2. The receiver810may include a set of radio frequency (RF) chains that are coupled with or otherwise utilize a set of antennas (for example, the set of antennas may be an example of aspects of the antennas252described with reference toFIG.2).

The transmitter820may transmit signals generated by the communications manager808or other components of the wireless communication device800. In some examples, the transmitter820may be collocated with the receiver810in a transceiver. The transmitter820may be an example of aspects of the transmit processor268described with reference toFIG.2. The transmitter820may be coupled with or otherwise utilize a set of antennas (for example, the set of antennas may be an example of aspects of the antennas252described with reference toFIG.2), which may be antenna elements shared with the receiver810. In some examples, the transmitter820is configured to transmit control information in a PUCCH, PSCCH, or PDCCH and data in a physical uplink shared channel (PUSCH), PSSCH, or PDSCH.

The communications manager808may be an example of aspects of the controller/processor259described with reference toFIG.2. The communications manager808may include the multiplexing component830, the feedback component840, and the priority component850. In some examples, working with the transmitter820, the multiplexing component830may multiplex a unicast message for a second UE with a multicast message for a group of UEs that includes the second UE. The unicast message may be multiplexed on one or more resources of a resource set associated with transmitting the multicast message. Additionally, working with the transmitter820, the multiplexing component830may transmit, to the group of UEs, the multiplexed unicast and multicast messages. Furthermore, working in conjunction with the receiver810, the feedback component840may receive, from the second UE, one or more HARQ)feedback messages including first HARQ feedback for the unicast message and second HARQ feedback for the multicast message based on transmitting the multiplexed unicast and multicast messages.

In some examples, working with the receiver810, a priority component850may receive, from a network node, an RRC message configuring the first UE to transmit, to a second UE, a unicast message associated with a first priority, or to transmit, to a group of UEs that includes the second UE, a multicast message associated with a second priority different than the first priority, based on one of the first priority or the second priority satisfying a priority condition. Furthermore, working with the transmitter820, the priority component850may transmit one of the unicast message or the multicast message based on one of the first priority or the second priority satisfying the priority condition. Furthermore, working in conjunction with the receiver810, the feedback component840may receive, from the second UE, a HARQ feedback message based on transmitting the one of the unicast message or the multicast message.

FIG.9is a flow diagram illustrating an example process900performed by a UE, in accordance with some aspects of the present disclosure. The UE may be an example of a first UE702described with reference toFIGS.7A and7B. The example process900is an example of multiplexing a unicast message and a multicast message. As shown inFIG.9, the process900begins at block902by multiplex a unicast message for a second UE with a multicast message for a group of UEs that includes the second UE. The unicast message may be multiplexed on one or more resources of a resource set associated with transmitting the multicast message. At block904, the process900may transmit, to the group of UEs, the multiplexed unicast and multicast messages. Furthermore, at block906, the process900may receive, from the second UE, one or more HARQ feedback messages including first HARQ feedback for the unicast message and second HARQ feedback for the multicast message based on transmitting the multiplexed unicast and multicast messages.

FIG.10is a flow diagram illustrating an example process1000performed by a UE, in accordance with some aspects of the present disclosure. The UE may be an example of a first UE702described with reference toFIGS.7A and7B. The example process1000is an example of multiplexing a unicast message and a multicast message. As shown inFIG.10, the process1000begins at block1002by receiving, from a network node, an RRC message configuring the first UE to transmit, to a second UE, a unicast message associated with a first priority, or to transmit, to a group of UEs that includes the second UE, a multicast message associated with a second priority different than the first priority, based on one of the first priority or the second priority satisfying a priority condition. At block1004, the process1000transmits one of the unicast message or the multicast message based on one of the first priority or the second priority satisfying the priority condition. At block1006, the process1000receives from the second UE, a HARQ feedback message based on transmitting the one of the unicast message or the multicast message

Clause 1. A method for wireless communication at a first UE, comprising: multiplexing a unicast message for a second UE with a multicast message for a group of UEs that includes the second UE, the unicast message being multiplexed on one or more resources of a resource set associated with transmitting the multicast message; transmitting, to the group of UEs, the multiplexed unicast and multicast messages; and receiving, from the second UE, one or more HARQ feedback messages including first HARQ feedback for the unicast message and second HARQ feedback for the multicast message based on transmitting the multiplexed unicast and multicast messages.
Clause 2. The method of Clause 1, further comprising receiving, from a network node, a first message configuring the first UE to allocate the one or more resources from the resource set for the unicast message.
Clause 3. The method of Clause 2, further comprising receiving, from the network node, a sidelink mode 1 message allocating the resource set for transmitting the multicast message, wherein the one or more resources are sidelink resources.
Clause 4. The method of Clause 2, further comprising receiving, from the network node, a semi-persistent scheduling (SPS) grant allocating the resource set for the multicast message.
Clause 5. The method of any one of Clauses 1-4, further comprising transmitting, to each UE of at least a subset of the group of UEs, a message indicating transmission of the multiplexed unicast and multicast messages is enabled at the first UE.
Clause 6. The method of any one of Clause 1-5, wherein: the multicast message is associated with a first priority; and the unicast message is associated with a second priority.
Clause 7. The method of Clause 6, wherein: the first priority and the second priority are a same low priority; and the first UE multiplexes the unicast message and multicast message based on both the first priority and the second priority being the same low priority.
Clause 8. The method of Clause 6, wherein: the first priority is different than the second priority; and the multiplexed unicast and multicast messages are transmitted based on the first UE satisfying a power condition associated with either: the multicast message based on the first priority being higher than the second priority; or the unicast message based on the second priority being higher than the first priority.
Clause 9. The method of any one of Clauses 1-8, wherein the one or more HARQ feedback messages include a first HARQ feedback message including the first HARQ feedback and a second HARQ feedback message including the second HARQ feedback.
Clause 10. The method of any one of Clauses 1-8, wherein the one or more HARQ feedback messages include a single HARQ feedback message including the first HARQ feedback bundled with the second HARQ feedback.
Clause 11. The method of any one of Clauses 1-10, wherein the one or more HARQ feedback messages are received via one or more physical sidelink feedback channels (PSFCHs).
Clause 12. A method for wireless communication at a first UE, comprising: receiving, from a network node, an RRC message configuring the first UE to transmit, to a second UE, a unicast message associated with a first priority, or to transmit, to a group of UEs that includes the second UE, a multicast message associated with a second priority different than the first priority, based on one of the first priority or the second priority satisfying a priority condition; transmitting one of the unicast message or the multicast message based on one of the first priority or the second priority satisfying the priority condition; and receiving, from the second UE, a HARQ feedback message based on transmitting the one of the unicast message or the multicast message.
Clause 13. The method of Clause 12, wherein the priority condition is satisfied based on one of the first priority or the second priority having a highest priority among the first priority and the second priority.
Clause 14. The method of Clause 13, wherein: the first priority is higher than the second priority; the first UE transmits the unicast message based on the first priority being higher than the second priority; and the HARQ feedback message includes HARQ feedback for the unicast message.
Clause 15. The method of Clause 13, wherein: the second priority is higher than the first priority; the first UE transmits the multicast message based on the second priority being higher than the first priority; and the HARQ feedback message includes HARQ feedback for the multicast message.

As used, the term “component” is intended to be broadly construed as hardware, firmware, and/or a combination of hardware and software. As used, a processor is implemented in hardware, firmware, and/or a combination of hardware and software.