Sidelink feedback channel signaling in new radio sidelink

Abstract

Methods, systems, and devices for wireless communication are described. A receiving device (e.g., a sidelink user equipment (UE), such as a first UE) can receive, from a second UE via a sidelink channel, a sidelink communication. The receiving device can transmit, to the second UE via a sidelink feedback channel using a first resource configuration, a feedback message based at least in part on the sidelink communication. The receiving device can identify a second resource configuration of the sidelink feedback channel associated with the sidelink communication via the sidelink feedback channel. The receiving device can perform, with the second UE via the sidelink feedback channel, the sidelink communication using the second resource configuration of the sidelink feedback channel.

Description

[0001] Cross-references

[0002] This patent application claims priority to U.S. Patent Application No. 17 / 147326, filed January 12, 2021, entitled “SIDELINK FEEDBACKCHANNEL SIGNALING IN NEW RADIO SIDELINK”, each of which is assigned to the assignee of this application and is expressly incorporated herein by reference. Technical Field

[0003] The following pertains to wireless communication, including sidelink feedback channel signaling in new radio sidelinks.

[0004] background

[0005] Wireless communication systems are widely deployed to provide various types of communication content, such as voice, video, packet data, message sending and receiving, and broadcasting. These systems can support communication with multiple users by sharing available system resources (e.g., time, frequency, and power). Examples of such multiple access systems include fourth-generation (4G) systems (such as Long Term Evolution (LTE), LTE-A Advanced (LTE-A), or LTE-A Pro systems) and fifth-generation (5G) systems, which may be referred to as New Radio (NR) systems. These systems can employ various technologies, such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), or Discrete Fourier Transform Extended Orthogonal Frequency Division Multiplexing (DFT-S-OFDM). A wireless multiple access communication system may include one or more base stations or one or more network access nodes, each of which simultaneously supports communication from multiple communication devices, which may also be referred to as User Equipment (UE).

[0006] Overview

[0007] The described technology relates to methods, systems, devices, and apparatuses for improving sidelink feedback channel signaling in new radio sidelinks. Typically, the described technology provides a long-format Physical Sidelink Feedback Channel (PSFCH) configuration to support inter-user equipment (UE) sidelink control signaling. For example, a UE may configure additional PSFCH resources that can then be used for control signaling and / or Hybrid Automatic Repeat / Request (HARQ) feedback signaling. Control signaling may include inter-UE communication, and in some examples, for simplicity, a Sidelink Control Message (SCI) type design may be used. Sidelink UEs may perform inter-UE communication and / or HARQ feedback signaling via additional PSFCH resources.

[0008] A method for performing wireless communication at a first UE is described. The method may include: receiving sidelink communication from a second UE via a sidelink channel; transmitting a feedback message to the second UE via a sidelink feedback channel using a first resource configuration, the feedback message being based on the sidelink communication; identifying a second resource configuration of the sidelink feedback channel associated with inter-UE communication via the sidelink feedback channel; and performing inter-UE communication with the second UE via the sidelink feedback channel using the second resource configuration of the sidelink feedback channel.

[0009] An apparatus for performing wireless communication at a first UE is described. The apparatus may include a processor, a memory in electronic communication with the processor, and instructions stored in the memory. These instructions are executable by the processor to cause the apparatus to: receive sidelink communication from a second UE via a sidelink channel; transmit a feedback message to the second UE via a sidelink feedback channel using a first resource configuration, the feedback message being based on the sidelink communication; identify a second resource configuration of the sidelink feedback channel associated with inter-UE communication via the sidelink feedback channel; and perform inter-UE communication with the second UE via the sidelink feedback channel using the second resource configuration of the sidelink feedback channel.

[0010] Another apparatus for performing wireless communication at a first UE is described. The apparatus may include: means for receiving sidelink communication from a second UE via a sidelink channel; means for transmitting a feedback message to the second UE via a sidelink feedback channel using a first resource configuration, the feedback message being based on the sidelink communication; means for identifying a second resource configuration of the sidelink feedback channel associated with inter-UE communication via the sidelink feedback channel; and means for performing inter-UE communication with the second UE via the sidelink feedback channel using the second resource configuration of the sidelink feedback channel.

[0011] A non-transient computer-readable medium is described, storing code for performing wireless communication at a first UE. The code may include instructions executable by a processor to: receive sidelink communication from a second UE via a sidelink channel; transmit a feedback message to the second UE via a sidelink feedback channel using a first resource configuration, the feedback message being based on the sidelink communication; identify a second resource configuration of the sidelink feedback channel associated with inter-UE communication via the sidelink feedback channel; and perform inter-UE communication with the second UE via the sidelink feedback channel using the second resource configuration of the sidelink feedback channel.

[0012] Some examples of the methods, apparatus (devices) and non-transient computer-readable media described herein may further include operations, features, means or instructions for receiving from a second UE, a different UE, or both, an instruction to perform inter-UE communication via a sidelink feedback channel using a second resource configuration.

[0013] Some examples of the methods, apparatus (devices) and non-transient computer-readable media described herein may further include operations, features, means or instructions for receiving signals configuring a second resource configuration from a second UE, a different UE, a base station or any combination thereof.

[0014] Some examples of the methods, apparatus (devices) and non-transient computer-readable media described herein may further include operations, features, means or instructions for multiplexing feedback messages with UE-to-UE communication via a sidelink feedback channel.

[0015] Some examples of the methods, apparatus (devices) and non-transient computer-readable media described herein may further include operations, features, means or instructions for transmitting feedback messages via a sidelink feedback channel separately from UE-to-UE communication via the sidelink feedback channel.

[0016] In some examples of the methods, apparatus (devices) and non-transient computer-readable media described herein, performing inter-UE communication may include operations, features, means, or instructions for transmitting inter-UE communication via a sidelink feedback channel based on a contention-free channel access procedure.

[0017] In some examples of the methods, apparatus (devices) and non-transient computer-readable media described herein, performing inter-UE communication may include operations, features, means, or instructions for performing a channel access procedure on a sidelink feedback channel and performing inter-UE communication via the sidelink feedback channel based on the results of the channel access procedure.

[0018] In some examples of the methods, apparatus (devices) and non-transient computer-readable media described herein, performing inter-UE communication may include operations, features, means, or instructions for monitoring sidelink control information messages that indicate that inter-UE communication may be performed in the future via a sidelink feedback channel, and performing inter-UE communication via the sidelink feedback channel based on the results of such monitoring.

[0019] In some examples of the methods, apparatus (devices) and non-transient computer-readable media described herein, performing inter-UE communication may include operations, features, means, or instructions for: transmitting a sidelink control information message indicating that a first UE may perform inter-UE communication via a sidelink feedback channel, and performing inter-UE communication via the sidelink feedback channel based on the sidelink control information message.

[0020] In some examples of the methods, apparatus (devices) and non-transient computer-readable media described herein, performing inter-UE transmission via a sidelink feedback channel may include operations, features, means, or instructions for transmitting, receiving, or simultaneously transmitting and receiving inter-UE communication via the sidelink feedback channel.

[0021] A method for performing wireless communication at a first UE is described. The method may include: transmitting sidelink communication to a second UE via a sidelink channel; receiving a feedback message from the second UE via a sidelink feedback channel using a first resource configuration, the feedback message being based on the sidelink communication; identifying a second resource configuration of the sidelink feedback channel associated with inter-UE communication via the sidelink feedback channel; and performing inter-UE communication with the second UE via the sidelink feedback channel using the second resource configuration of the sidelink feedback channel.

[0022] An apparatus for performing wireless communication at a first UE is described. The apparatus may include a processor, a memory in electronic communication with the processor, and instructions stored in the memory. These instructions are executable by the processor to cause the apparatus to: transmit sidelink communication to a second UE via a sidelink channel; receive a feedback message from the second UE via a sidelink feedback channel using a first resource configuration, the feedback message being based on the sidelink communication; identify a second resource configuration of the sidelink feedback channel associated with inter-UE communication via the sidelink feedback channel; and perform inter-UE communication with the second UE via the sidelink feedback channel using the second resource configuration of the sidelink feedback channel.

[0023] Another apparatus for performing wireless communication at a first UE is described. The apparatus may include: means for transmitting sidelink communication to a second UE via a sidelink channel; means for receiving a feedback message from the second UE via a sidelink feedback channel using a first resource configuration, the feedback message being based on the sidelink communication; means for identifying a second resource configuration of the sidelink feedback channel associated with inter-UE communication via the sidelink feedback channel; and means for performing inter-UE communication with the second UE via the sidelink feedback channel using the second resource configuration of the sidelink feedback channel.

[0024] A non-transient computer-readable medium is described, storing code for performing wireless communication at a first UE. The code may include instructions executable by a processor to: transmit sidelink communication to a second UE via a sidelink channel; receive a feedback message from the second UE via a sidelink feedback channel using a first resource configuration, the feedback message being based on the sidelink communication; identify a second resource configuration of the sidelink feedback channel associated with inter-UE communication via the sidelink feedback channel; and perform inter-UE communication with the second UE via the sidelink feedback channel using the second resource configuration of the sidelink feedback channel.

[0025] Some examples of the methods, apparatus (devices) and non-transient computer-readable media described herein may further include operations, features, means or instructions for transmitting to a second UE, a different UE, or both, an instruction to perform inter-UE communication via a sidelink feedback channel using a second resource configuration.

[0026] Some examples of the methods, apparatus (devices) and non-transient computer-readable media described herein may further include operations, features, means or instructions for transmitting signals configuring a second resource configuration to a second UE, a different UE, a base station or any combination thereof.

[0027] In some examples of the methods, apparatus (devices) and non-transient computer-readable media described herein, feedback messages may be multiplexed with communication between UEs via a sidelink feedback channel.

[0028] Some examples of the methods, apparatus (devices) and non-transient computer-readable media described herein may further include operations, features, means or instructions for receiving feedback messages via a sidelink feedback channel separately from UE-to-UE communication via the sidelink feedback channel.

[0029] In some examples of the methods, apparatus (devices) and non-transient computer-readable media described herein, performing inter-UE communication may include operations, features, means, or instructions for transmitting inter-UE communication via a sidelink feedback channel based on a contention-free channel access procedure.

[0030] In some examples of the methods, apparatus (devices) and non-transient computer-readable media described herein, performing inter-UE communication may include operations, features, means, or instructions for performing a channel access procedure on a sidelink feedback channel and performing inter-UE communication via the sidelink feedback channel based on the results of the channel access procedure.

[0031] In some examples of the methods, apparatus (devices) and non-transient computer-readable media described herein, performing inter-UE communication may include operations, features, means, or instructions for: transmitting a sidelink control information message indicating that inter-UE communication may be performed via a sidelink feedback channel, and performing inter-UE communication via a sidelink feedback channel based on the result of the sidelink control information message.

[0032] In some examples of the methods, apparatus (devices) and non-transient computer-readable media described herein, performing inter-UE communication may include operations, features, means, or instructions for: receiving a sidelink control information message indicating that a second UE may perform inter-UE communication via a sidelink feedback channel, and performing inter-UE communication via the sidelink feedback channel based on the sidelink control information message.

[0033] In some examples of the methods, apparatus (devices) and non-transient computer-readable media described herein, performing inter-UE transmission via a sidelink feedback channel may include operations, features, means, or instructions for transmitting, receiving, or simultaneously transmitting and receiving inter-UE communication via the sidelink feedback channel. Brief description of the attached diagram

[0035] Figure 1 Examples of wireless communication systems supporting sidelink feedback channel signaling in a new radio sidelink are explained according to various aspects of this disclosure.

[0036] Figure 2 Examples of wireless communication systems supporting sidelink feedback channel signaling in a new radio sidelink are explained according to various aspects of this disclosure.

[0037] Figure 3 Examples of feedback configurations supporting sidelink feedback channel signaling in new radio sidelinks are explained according to various aspects of this disclosure.

[0038] Figure 4 Examples of feedback configurations supporting sidelink feedback channel signaling in new radio sidelinks are explained according to various aspects of this disclosure.

[0039] Figure 5 and 6 A block diagram of an apparatus supporting sidelink feedback channel signaling in a new radio sidelink is shown, according to various aspects of this disclosure.

[0040] Figure 7 A block diagram of a communication manager supporting sidelink feedback channel signaling in a new radio sidelink, according to various aspects of this disclosure, is shown.

[0041] Figure 8A diagram of a system including a device supporting sidelink feedback channel signaling in a new radio sidelink, according to various aspects of this disclosure, is shown.

[0042] Figures 9 to 13 A flowchart illustrating a method for supporting sidelink feedback channel signaling in a new radio sidelink according to various aspects of this disclosure is shown.

[0043] Detailed description

[0044] Wireless communication supports sidelink communication (e.g., communication between User Equipment (UEs) via sidelink channels such as the Physical Sidelink Shared Channel (PSSCH)). Sidelink protocols support Hybrid Automatic Repeat / Request (HARQ) feedback signaling via the Physical Sidelink Feedback Channel (PSFCH). This PSFCH can be enabled for both unicast and multicast transmissions and is configured during the last two symbols of a time slot. However, PSFCH usage is generally low and limited to HARQ feedback messages. Furthermore, sidelink communication is typically scheduled / configured using Sidelink Control Information (SCI) messages communicated via the PSSCH and Sidelink Control Channel (PSCCH). However, other control signaling information (e.g., communication between UEs) may be more advantageous to communicate using SCI format messages.

[0045] The aspects of this disclosure are initially described in the context of wireless communication systems. Typically, the described techniques provide long-format PSFCH configurations to support inter-UE sidelink control signaling. For example, a UE may configure additional PSFCH resources, which can then be used for control signaling and / or HARQ feedback signaling. Control signaling may include inter-UE communication, and in some examples, for simplicity, an SCI-type design may be used. Sidelink UEs may perform inter-UE communication and / or HARQ feedback signaling via additional PSFCH resources.

[0046] Various aspects of this disclosure are further explained and described with reference to apparatus diagrams, system diagrams and flowcharts relating to sidelink feedback channel signaling in a new radio sidelink.

[0047] Figure 1Examples of a wireless communication system 100 supporting sidelink feedback channel signaling in a new radio sidelink, according to various aspects of this disclosure, are described. The wireless communication system 100 may include one or more base stations 105, one or more UEs 115, and a core network 130. In some examples, the wireless communication system 100 may be a Long Term Evolution (LTE) network, an Advanced LTE (LTE-A) network, an LTE-A Pro network, or a New Radio (NR) network. In some examples, the wireless communication system 100 may support enhanced broadband communication, ultra-reliable (e.g., mission-critical) communication, low latency communication, communication with low-cost and low-complexity devices, or any combination thereof.

[0048] Base station 105 can be distributed across a geographical area to form wireless communication system 100, and can be different types of devices or devices with different capabilities. Base station 105 and UE 115 can communicate wirelessly via one or more communication links 125. Each base station 105 can provide a coverage area 110, and UE 115 and base station 105 can establish one or more communication links 125 on the coverage area 110. Coverage area 110 can be an example of a geographical area over which base station 105 and UE 115 can support signal communication according to one or more radio access technologies.

[0049] Each UE 115 can be distributed throughout the coverage area 110 of the wireless communication system 100, and each UE 115 can be stationary or mobile, or stationary and mobile at different times. Each UE 115 can be a different type of device or a device with different capabilities. Figure 1 The document describes some example UE 115s. The UE 115 described herein can communicate with various types of devices, such as other UE 115s, base station 105, or network equipment (e.g., core network nodes, relay equipment, integrated access and backhaul (IAB) nodes, or other network equipment). Figure 1 As shown in the image.

[0050] Each base station 105 may communicate with the core network 130, or with each other, or both. For example, base station 105 may interface with the core network 130 via one or more backhaul links 120 (e.g., via S1, N2, N3, or other interfaces). Base stations 105 may communicate with each other directly (e.g., directly between base stations 105), indirectly (e.g., via the core network 130), or directly and indirectly on backhaul links 120 (e.g., via X2, Xn, or other interfaces). In some examples, backhaul link 120 may be or include one or more radio links.

[0051] One or more of the base stations 105 described herein may include, or may be referred to by those skilled in the art as, base transceiver station, radio base station, access point, radio transceiver, B node, evolved B node (eNB), next-generation B node or gigabit B node (any of which may be referred to as gNB), home B node, home evolved B node, or other suitable terms.

[0052] UE 115 may include or be referred to as a mobile device, wireless device, remote device, handheld device, or subscriber device, or any other suitable term, wherein "device" may also be referred to as a cell, station, terminal, or client, etc. UE 115 may also include or be referred to as a personal electronic device, such as a cellular phone, personal digital assistant (PDA), tablet computer, laptop computer, or personal computer. In some examples, UE 115 may include or be referred to as a wireless local loop (WLL) station, Internet of Things (IoT) device, Internet of Everything (IoE) device, or machine-type communication (MTC) device, which may be implemented in various objects such as appliances or vehicles, meters, etc.

[0053] The UE 115 described herein can communicate with various types of devices, such as other UEs 115 that sometimes act as relays, as well as base station 105 and network equipment including macro eNBs or gNBs, small cell eNBs or gNBs, relay base stations, etc. Figure 1 As shown in the image.

[0054] UE 115 and base station 105 can wirelessly communicate with each other via one or more communication links 125 on one or more carriers. The term "carrier" can refer to a set of radio frequency spectrum resources having a defined physical layer structure for supporting communication link 125. For example, a carrier for communication link 125 may include a portion of the radio spectrum band (e.g., a bandwidth portion (BWP)) operating according to one or more physical layer channels for a given radio access technology (e.g., LTE, LTE-A, LTE-A Pro, NR). Each physical layer channel may carry acquisition signaling (e.g., synchronization signals, system information), control signaling coordinating carrier operation, user data, or other signaling. Wireless communication system 100 may support communication with UE 115 using carrier aggregation or multi-carrier operation. UE 115 may be configured to have multiple downlink component carriers and one or more uplink component carriers according to a carrier aggregation configuration. Carrier aggregation can be used in conjunction with frequency division duplex (FDD) and time division duplex (TDD) component carriers.

[0055] In some examples (e.g., in a carrier aggregation configuration), the carrier may also have acquisition signaling or control signaling to coordinate the operation of other carriers. The carrier may be associated with a frequency channel (e.g., an Evolved Universal Mobile Telecommunications System Terrestrial Radio Access (E-UTRA) Absolute Radio Frequency Channel Number (EARFCN)) and may be located according to a channel grid for discovery by UE 115. The carrier may operate in an autonomous mode in which initial acquisition and connection can be performed by UE 115 via that carrier, or in a non-autonomous mode in which the carrier may connect to carriers anchored using different carriers (e.g., different carriers of the same or different radio access technologies).

[0056] The communication link 125 shown in the wireless communication system 100 may include uplink transmission from UE 115 to base station 105, or downlink transmission from base station 105 to UE 115. The carrier may carry downlink or uplink communication (e.g., in FDD mode), or may be configured to carry both downlink and uplink communication (e.g., in TDD mode).

[0057] A carrier may be associated with a specific bandwidth of the radio frequency spectrum, and in some examples, this carrier bandwidth may be referred to as the carrier or the “system bandwidth” of the wireless communication system 100. For example, the carrier bandwidth may be one of several defined bandwidths (e.g., 1.4, 3, 5, 10, 15, 20, 40, or 80 MHz) of a carrier for a particular radio access technology. Devices of the wireless communication system 100 (e.g., base station 105, UE 115, or both) may have a hardware configuration that supports communication over a specific carrier bandwidth, or may be configurable to support communication over a single carrier bandwidth within a set of carrier bandwidths. In some examples, the wireless communication system 100 may include a base station 105 or UE 115 that supports simultaneous communication via carriers associated with multiple carrier bandwidths. In some examples, each served UE 115 may be configured to operate over a portion (e.g., a subband, BWP) or all of the carrier bandwidth.

[0058] The signal waveform transmitted on the carrier may include multiple subcarriers (e.g., using multi-carrier modulation (MCM) techniques, such as orthogonal frequency division multiplexing (OFDM) or discrete Fourier transform extended OFDM (DFT-S-OFDM)). In a system employing MCM, a resource element may include a symbol period (e.g., the duration of a modulation symbol) and a subcarrier, where the symbol period and subcarrier spacing are inversely related. The number of bits carried by each resource element may depend on the modulation scheme (e.g., the order of the modulation scheme, the code rate of the modulation scheme, or both). Thus, the more resource elements the UE 115 receives and the higher the order of the modulation scheme, the higher the data rate the UE 115 can achieve. Wireless communication resources can refer to a combination of radio frequency spectrum resources, temporal resources, and spatial resources (e.g., spatial layers or beams), and using multiple spatial layers can further improve the data rate or data integrity of communication with the UE 115.

[0059] One or more parameter designs for a carrier can be supported, where the parameter design may include a subcarrier spacing (Δf) and a cyclic prefix. A carrier can be divided into one or more BWPs with the same or different parameter designs. In some examples, UE 115 can be configured with multiple BWPs. In some examples, a single BWP for a carrier can be active at a given time, and communication for UE 115 can be limited to one or more active BWPs.

[0060] The time interval of base station 105 or UE 115 can be expressed as a multiple of a basic time unit, such as the sampling period T. s =1 / (Δf) max ·N f ) seconds, where Δf max This can represent the maximum supported subcarrier spacing, while N f This can represent the maximum supported Discrete Fourier Transform (DFT) size. The time interval of the communication resources can be organized according to radio frames, each with a specified duration (e.g., 10 milliseconds (ms)). Each radio frame can be identified by a System Frame Number (SFN) (e.g., ranging from 0 to 1023).

[0061] Each frame may include multiple consecutively numbered subframes or time slots, and each subframe or time slot may have the same duration. In some examples, a frame may (e.g., in the time domain) be divided into subframes, and each subframe may be further divided into several time slots. Alternatively, each frame may include a variable number of time slots, and the number of time slots may depend on the subcarrier spacing. Each time slot may include several symbol periods (e.g., depending on the length of the cyclic prefix added before each symbol period). In some wireless communication systems 100, time slots may be further divided into multiple mini-time slots containing one or more symbols. Excluding the cyclic prefix, each symbol period may contain one or more (e.g., N) symbols. f (Number) sampling periods. The duration of a symbol period can depend on the subcarrier interval or the operating frequency band.

[0062] A subframe, time slot, mini-slot, or symbol can be the smallest scheduling unit of the wireless communication system 100 (e.g., in the time domain) and can be referred to as a transmission time interval (TTI). In some examples, the duration of the TTI (e.g., the number of symbol periods in the TTI) can be variable. Additionally or alternatively, the smallest scheduling unit of the wireless communication system 100 can be dynamically selected (e.g., in bursts of shortened TTIs (sTTIs)).

[0063] Physical channels can be multiplexed on a carrier using various techniques. Physical control channels and physical data channels can be multiplexed on a downlink carrier, for example, using one or more of Time Division Multiplexing (TDM), Frequency Division Multiplexing (FDM), or a hybrid TDM-FDM technique. A control region (e.g., a control resource set (CORESET)) for physical control channels can be defined by the number of symbol periods and can extend across the system bandwidth or a subset of the system bandwidth of the carrier. One or more control regions (e.g., CORESETs) can be configured for a set of UEs 115. For example, one or more of the UEs 115 can monitor or search control regions for control information based on one or more search space sets, and each search space set can include one or more control channel candidates in one or more aggregation levels arranged in a cascaded manner. An aggregation level for control channel candidates can refer to the number of control channel resources (e.g., control channel elements (CCEs)) associated with coded information in a control information format having a given payload size. The search space set may include a common search space set configured to send control information to multiple UEs 115 and a UE-specific search space set configured to send control information to a specific UE 115.

[0064] Each base station 105 may provide communication coverage via one or more cells (e.g., macrocells, small cells, hotspots, or other types of cells, or any combination thereof). The term "cell" may refer to a logical communication entity used to communicate with base station 105 (e.g., on a carrier) and may be associated with an identifier used to distinguish adjacent cells (e.g., Physical Cell Identifier (PCID), Virtual Cell Identifier (VCID), or others). In some examples, a cell may also refer to a geographic coverage area 110 or a portion of geographic coverage area 110 (e.g., a sector) on which a logical communication entity operates. The extent of such cells may vary from smaller areas (e.g., structures, subsets of structures) to larger areas depending on various factors (such as the capabilities of base station 105). For example, a cell may be or include buildings, subsets of buildings, or external space between or overlapping geographic coverage areas 110, among other examples.

[0065] Macrocells typically cover a relatively large geographic area (e.g., a radius of several kilometers) and allow unrestricted access for UEs 115 that have service subscriptions with a network provider supporting the macrocell. Small cells may be associated with a lower-power base station 105 (compared to macrocells) and may operate in the same or different (e.g., licensed or unlicensed) frequency bands as macrocells. Small cells may provide unrestricted access to UEs 115 that have service subscriptions with a network provider, or may provide restricted access to UEs 115 associated with the small cell (e.g., UEs 115 in a Closed Subscriber Group (CSG), or UEs 115 associated with a user in a home or office). Base station 105 may support one or more cells and may also support communication on one or more cells using one or more component carriers.

[0066] In some examples, a carrier can support multiple cells and can be configured with different cells based on different protocol types that can provide access for different types of devices (e.g., MTC, Narrowband IoT (NB-IoT), Enhanced Mobile Broadband (eMBB)).

[0067] In some examples, base station 105 may be mobile, and thus provide communication coverage to mobile geographic coverage areas 110. In some examples, different geographic coverage areas 110 associated with different technologies may overlap, but the different geographic coverage areas 110 may be supported by the same base station 105. In other examples, overlapping geographic coverage areas 110 associated with different technologies may be supported by different base stations 105. Wireless communication system 100 may include, for example, a heterogeneous network, in which different types of base stations 105 use the same or different radio access technologies to provide coverage to various geographic coverage areas 110.

[0068] The wireless communication system 100 can support synchronous or asynchronous operation. For synchronous operation, base stations 105 can have similar frame timing, and transmissions from different base stations 105 can be approximately time-aligned. For asynchronous operation, base stations 105 can have different frame timing, and transmissions from different base stations 105 may not be time-aligned in some examples. The techniques described herein can be used for both synchronous and asynchronous operation.

[0069] Some UE 115 devices (such as MTC or IoT devices) can be low-cost or low-complexity devices and can provide automated communication between machines (e.g., via machine-to-machine (M2M) communication). M2M communication or MTC can refer to data communication technologies that allow devices to communicate with each other or with base station 105 without human intervention. In some examples, M2M communication or MTC may include communication from devices that have integrated sensors or meters to measure or capture information and relay such information to a central server or application that uses the information or presents it to people interacting with the application. Some UE 115 devices may be designed to collect information or automate the behavior of machines or other devices. Examples of applications for MTC devices include: smart metering, inventory monitoring, water level monitoring, equipment monitoring, healthcare monitoring, wilderness survival monitoring, weather and geographic event monitoring, queue management and tracking, remote security sensing, physical access control, and transaction-based commercial toll collection.

[0070] Some UEs 115 can be configured to operate in reduced-power modes, such as half-duplex communication (e.g., a mode that supports unidirectional communication via transmission or reception but not simultaneous transmission and reception). In some examples, half-duplex communication can be performed at a reduced peak rate. Other power-saving techniques for UEs 115 include entering a power-saving deep sleep mode when not engaged in active communication, operating on limited bandwidth (e.g., according to narrowband communication), or a combination of these techniques. For example, some UEs 115 can be configured to operate using a narrowband protocol type associated with a defined portion or range (e.g., a subcarrier or resource block (RB) set) within the carrier, within the carrier's guard band, or outside the carrier.

[0071] Wireless communication system 100 may be configured to support ultra-reliable communication or low latency communication, or various combinations thereof. For example, wireless communication system 100 may be configured to support ultra-reliable low latency communication (URLLC) or mission-critical communication. UE 115 may be designed to support ultra-reliable, low latency, or mission-critical functions (e.g., mission-critical functions). Ultra-reliable communication may include private or group communication and may be supported by one or more mission-critical services, such as Mission-Critical Talk-to-Talk (MCPTT), Mission-Critical Video (MCVideo), or Mission-Critical Data (MCData)). Support for mission-critical functions may include prioritization of services, and mission-critical services may be used for public safety or general business applications. The terms ultra-reliable, low latency, mission-critical, and ultra-reliable low latency are used interchangeably herein.

[0072] In some examples, UE 115 may also be able to communicate directly with other UE 115 on a device-to-device (D2D) communication link 135 (e.g., using a peer-to-peer (P2P) or D2D protocol). One or more UE 115s utilizing D2D communication may be within the geographic coverage area 110 of base station 105. Other UE 115s in such a group may be outside the geographic coverage area 110 of base station 105 or may be unable to receive transmissions from base station 105 for other reasons. In some examples, groups of UE 115s communicating via D2D communication may utilize a one-to-many (1:M) system, where each UE 115 transmits to every other UE 115 in the group. In some examples, base station 105 facilitates the scheduling of resources for D2D communication. In other cases, D2D communication is performed between the individual UE 115s without involving base station 105.

[0073] In some systems, the D2D communication link 135 may be an example of a communication channel (such as a sidelink communication channel) between vehicles (e.g., UE 115). In some examples, vehicles may communicate using vehicle-to-vehicle (V2X) communication, vehicle-to-vehicle (V2V) communication, or some combination of these communications. Vehicles may signal information related to traffic conditions, signaling, weather, safety, emergencies, or any other information relevant to the V2X system. In some examples, vehicles in a V2X system may communicate via vehicle-to-network (V2N) communication through one or more network nodes (e.g., base station 105) with roadside infrastructure (such as roadside units), or with the network, or with both.

[0074] Core network 130 provides user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. Core network 130 can be an evolved packet core (EPC) or a 5G core (5GC). The EPC or 5GC may include at least one control plane entity (e.g., a Mobility Management Entity (MME), Access and Mobility Management Function (AMF)) managing access and mobility, and at least one user plane entity (e.g., a Serving Gateway (S-GW), Packet Data Network (PDN) Gateway (P-GW), or User Plane Function (UPF)) routing packets or interconnecting to external networks. The control plane entity manages non-access stratum (NAS) functions, such as mobility, authentication, and bearer management of UE 115 served by base station 105 associated with core network 130. User IP packets can be delivered through the user plane entity, which provides IP address allocation and other functions. The user plane entity may be connected to one or more network operator IP services 150. IP services 150 may include access to the Internet, intranets, IP Multimedia Subsystem (IMS), or packet-switched streaming services.

[0075] Some network devices (such as base station 105) may include sub-components, such as access network entity 140, which may be an example of an access node controller (ANC). Each access network entity 140 may communicate with each UE 115 through one or more other access network transport entities 145, which may be referred to as a radio headend, smart radio headend, or transmit / receive point (TRP). Each access network transport entity 145 may include one or more antenna panels. In some configurations, the various functions of each access network entity 140 or base station 105 may be distributed across various network devices (e.g., radio headends and ANCs) or combined into a single network device (e.g., base station 105).

[0076] Wireless communication system 100 can operate using one or more frequency bands, typically in the range of 300 MHz to 300 GHz. Generally, the 300 MHz to 3 GHz band is referred to as a UHF band or decimeter band because the wavelengths range from approximately 1 decimeter to 1 meter. UHF waves can be blocked or redirected by buildings and environmental features, but these waves can penetrate various structures sufficiently for macrocells to provide service to UE 115 located indoors. Compared to transmissions using smaller frequencies and longer waves in the lower HF or VHF portions of the spectrum below 300 MHz, UHF wave transmission can be associated with smaller antennas and shorter ranges (e.g., less than 100 km).

[0077] The wireless communication system 100 can also operate in the ultra-high frequency (SHF) zoning using a frequency band from 3 GHz to 30 GHz (also known as the centimeter band) or in the extremely high frequency (EHF) zoning using a spectrum (e.g., from 30 GHz to 300 GHz) (also known as the millimeter band). In some examples, the wireless communication system 100 can support millimeter-wave (mmW) communication between the UE 115 and the base station 105, and the EHF antennas of the corresponding devices can be smaller and more closely spaced than UHF antennas. In some examples, this can facilitate the use of antenna arrays within the device. However, the propagation of EHF transmissions may suffer even greater atmospheric attenuation and shorter range than SHF or UHF transmissions. The techniques disclosed herein can be employed across transmissions using one or more different frequency zonings, and the frequency band usage specified across these frequency zonings may vary by country or regulatory authority.

[0078] Wireless communication system 100 may utilize both licensed and unlicensed radio spectrum bands. For example, wireless communication system 100 may employ licensed assisted access (LAA), LTE unlicensed (LTE-U) radio access technology, or NR technology in unlicensed frequency bands (such as the 5 GHz Industrial, Scientific, and Medical (ISM) band). When operating in unlicensed radio spectrum bands, devices (such as base station 105 and UE 115) may employ carrier sensing for collision detection and avoidance. In some examples, operation in unlicensed frequency bands may be based on carrier aggregation configuration (e.g., LAA) in coordination with component carriers operating in licensed frequency bands. Operation in unlicensed spectrum may include downlink transmissions, uplink transmissions, P2P transmissions, or D2D transmissions, etc.

[0079] Base station 105 or UE 115 may be equipped with multiple antennas that can be used to employ technologies such as transmit diversity, receive diversity, multiple-input multiple-output (MIMO) communication, or beamforming. The antennas of base station 105 or UE 115 may be located within one or more antenna arrays or antenna panels that can support MIMO operation or transmit or receive beamforming. For example, one or more base station antennas or antenna arrays may be co-located at an antenna assembly (such as an antenna tower). In some examples, the antennas or antenna arrays associated with base station 105 may be located in different geographical locations. Base station 105 may have an antenna array with several rows and columns of antenna ports that base station 105 can use to support beamforming for communication with UE 115. Similarly, UE 115 may have one or more antenna arrays that can support various MIMO or beamforming operations. Additionally or alternatively, the antenna panel may support radio frequency beamforming for signals transmitted via the antenna ports.

[0080] Base station 105 or UE 115 can use MIMO communication to leverage multipath signal propagation and improve spectral efficiency by transmitting or receiving multiple signals via different spatial layers. This technique is known as spatial multiplexing. For example, a transmitting device may transmit multiple signals via different antennas or different combinations of antennas. Similarly, a receiving device may receive multiple signals via different antennas or different combinations of antennas. Each of the multiple signals may be referred to as a separate spatial stream and may carry bits associated with the same data stream (e.g., the same codeword) or different data streams (e.g., different codewords). Different spatial layers may be associated with different antenna ports used for channel measurement and reporting. MIMO techniques include single-user MIMO (SU-MIMO), where multiple spatial layers are transmitted to the same receiving device; and multi-user MIMO (MU-MIMO), where multiple spatial layers are transmitted to multiple devices.

[0081] Beamforming (also known as spatial filtering, directional transmission, or directional reception) is a signal processing technique that can be used at a transmitting or receiving device (e.g., base station 105, UE 115) to shape or guide an antenna beam (e.g., a transmit beam, a receive beam) along a spatial path between the transmitting and receiving devices. Beamforming can be achieved by combining signals transmitted via antenna elements of an antenna array, such that some signals propagating relative to a particular orientation of the antenna array experience constructive interference, while others experience destructive interference. Adjustments to the signals transmitted via the antenna elements may include the transmitting or receiving device applying amplitude offset, phase offset, or both to the signals carried via the antenna elements associated with that device. The adjustments associated with each antenna element may be defined by a beamforming weight set associated with a particular orientation (e.g., the antenna array relative to the transmitting or receiving device, or relative to some other orientation).

[0082] Base station 105 or UE 115 may use beamsweeping techniques as part of beamforming operations. For example, base station 105 may use multiple antennas or antenna arrays (e.g., antenna panels) to perform beamforming operations for directional communication with UE 115. Some signals (e.g., synchronization signals, reference signals, beam selection signals, or other control signals) may be transmitted multiple times by base station 105 in different directions. For example, base station 105 may transmit signals according to different beamforming weight sets associated with different transmission directions. Transmissions in different beam directions may be used (e.g., by the transmitting device (such as base station 105) or the receiving device (such as UE 115)) to identify the beam direction that base station 105 will use for later transmission or reception.

[0083] Some signals (such as data signals associated with a specific receiving device) may be transmitted by base station 105 in a single beam direction (e.g., the direction associated with the receiving device (such as UE 115)). In some examples, the beam direction associated with transmission along a single beam direction may be determined based on the signals transmitted in one or more beam directions. For example, UE 115 may receive one or more signals transmitted by base station 105 in different directions and may report to base station 105 an indication of the signals received by UE 115 with the highest signal quality or other acceptable signal quality.

[0084] In some examples, transmissions performed by a device (e.g., by base station 105 or UE 115) may be executed using multiple beam directions, and the device may use a combination of digital precoding or radio frequency beamforming to generate combined beams for transmission (e.g., from base station 105 to UE 115). UE 115 may report feedback indicating precoding weights for one or more beam directions, and this feedback may correspond to a configured number of beams across the system bandwidth or one or more subbands. Base station 105 may transmit reference signals that may be precoded or unprecoded (e.g., cell-specific reference signals (CRS), channel state information reference signals (CSI-RS)). UE 115 may provide feedback for beam selection, which may be a precoding matrix indicator (PMI) or codebook-based feedback (e.g., multi-panel type codebook, linear combination type codebook, port selection type codebook). Although these techniques are described with reference to signals transmitted by base station 105 in one or more directions, UE 115 may use similar techniques to transmit signals multiple times in different directions (e.g., to identify the beam direction used by UE 115 for subsequent transmission or reception) or to transmit signals in a single direction (e.g., to transmit data to a receiving device).

[0085] A receiver device (e.g., UE 115) may attempt multiple receive configurations (e.g., directional listening) when receiving various signals (such as synchronization signals, reference signals, beam selection signals, or other control signals) from base station 105. For example, the receiver device may attempt multiple receive directions by: receiving via different antenna subarrays; processing received signals according to different antenna subarrays; receiving according to different sets of receive beamforming weights applied to signals received at multiple antenna elements of the antenna array (e.g., different directional listening weight sets); or processing received signals according to different sets of receive beamforming weights applied to signals received at multiple antenna elements of the antenna array, any of which may be referred to as "listening" according to different receive configurations or receive directions. In some examples, the receiver device may use a single receive configuration to receive along a single beam direction (e.g., when receiving a data signal). The single receive configuration may be aligned on a beam direction determined based on listening according to different receive configuration directions (e.g., a beam direction determined to have the highest signal strength, highest signal-to-noise ratio (SNR), or other acceptable signal quality based on listening according to multiple beam directions).

[0086] The wireless communication system 100 can be a packet-based network operating according to a layered protocol stack. In the user plane, communication at the bearer or Packet Data Convergence Protocol (PDCP) layer can be IP-based. The Radio Link Control (RLC) layer performs packet segmentation and reassembly for communication on logical channels. The Media Access Control (MAC) layer performs priority handling and multiplexes logical channels into transport channels. The MAC layer can also use error detection, error correction, or both to support MAC layer retransmissions to improve link efficiency. In the control plane, the Radio Resource Control (RRC) protocol layer can provide the establishment, configuration, and maintenance of RRC connections between the UE 115 and the base station 105 or core network 130 that support user plane data radio bearers. At the physical layer, transport channels can be mapped to physical channels.

[0087] UE 115 and base station 105 can support data retransmission to increase the likelihood of successful data reception. Hybrid Automatic Repeat Request (HARQ) feedback is a technique used to increase the likelihood of correctly receiving data on communication link 125. HARQ may include a combination of error detection (e.g., using Cyclic Redundancy Check (CRC)), forward error correction (FEC), and retransmission (e.g., Automatic Repeat Request (ARQ)). HARQ can improve MAC layer throughput in poor radio conditions (e.g., low signal-to-noise ratio conditions). In some examples, the device may support simultaneous time-slot HARQ feedback, where the device can provide HARQ feedback in a specific time slot for data received in previous symbols within that time slot. In other cases, the device may provide HARQ feedback in subsequent time slots or according to some other time interval.

[0088] UE 115 (e.g., the first UE in this example, which may also be referred to as the receiving device) receives sidelink communication from the second UE via a sidelink channel. UE 115 may use a first resource configuration to transmit a feedback message to the second UE via a sidelink feedback channel, the feedback message being at least partially based on the sidelink communication. UE 115 may identify a second resource configuration of the sidelink feedback channel associated with the inter-UE communication via the sidelink feedback channel. UE 115 may use the second resource configuration of the sidelink feedback channel to perform inter-UE communication with the second UE via the sidelink feedback channel.

[0089] UE 115 (e.g., a first UE in this example, which may also be referred to as a transmitting device) transmits sidelink communication to a second UE via a sidelink channel. UE 115 may use a first resource configuration to transmit a feedback message to the second UE via a sidelink feedback channel, the feedback message being at least partially based on the sidelink communication. UE 115 may identify a second resource configuration of the sidelink feedback channel associated with the inter-UE communication via the sidelink feedback channel. UE 115 may use the second resource configuration of the sidelink feedback channel to perform inter-UE communication with the second UE via the sidelink feedback channel.

[0090] That is, references to the first UE and / or the second UE herein may depend on the context / perspective of that particular discussion. For example, in some cases, the first UE may refer to UE 115, which receives sidelink communication from and transmits feedback messages for sidelink communication to the second UE. In this example, the first UE may refer to a receiving device (e.g., UE 115, which receives sidelink communication and transmits feedback messages), while the second UE may refer to a transmitting device (e.g., UE 115, which transmits sidelink communication and receives feedback messages from the first UE). In other examples, the first UE may refer to UE 115, which transmits sidelink communication to and receives feedback messages for sidelink communication from the second UE. In this example, the first UE may refer to a transmitting device (e.g., UE 115, which transmits sidelink communication and receives feedback messages), while the second UE may refer to a receiving device (e.g., UE 115, which receives sidelink communication and transmits feedback messages to the first UE). Accordingly, for simplicity, aspects of the technology described herein may use the terms transmitting device and receiving device instead of first UE / second UE.

[0091] Figure 2Examples of a wireless communication system 200 supporting sidelink feedback channel signaling in a new radio sidelink, according to various aspects of this disclosure, are described. The wireless communication system 200 may implement various aspects of the wireless communication system 100. The wireless communication system 200 may include UE 205 and UE 210, which may be examples of the corresponding devices described herein. Generally, UE 205 may be referred to as a transmitting device, and UE 210 may be referred to as a receiving device.

[0092] The wireless communication system 200 may support sidelink communication (e.g., inter-UE communication via sidelink channels). The sidelink protocol supports HARQ feedback signaling via a sidelink feedback channel (e.g., PSFCH). The PSFCH resource may be enabled for both unicast and multicast transmissions. For example, the PSFCH resource may use the PUCCH format 0 waveform structure. The PSFCH resource may use one bit to transmit ACK / NACK feedback for unicast transmissions. For multicast transmissions, the PSFCH resource may be used to indicate NACK only, or it may be used for ACK / NACK feedback. This type of legacy PSFCH resource may also be referred to as the first resource configuration.

[0093] PSFCH resources (e.g., first resource configuration) can be configured during the last two symbol periods of a time slot, may have corresponding time intervals (e.g., {0,1,2,4}), and may use zero (“0”) to indicate that PSFCH is disabled. Such indications are typically carried in a single bit of SCI-1 (which is usually carried via PSCCH or otherwise transmitted). PSFCH resources may have a minimum time slot of two or three symbols (e.g., {2,3}), which typically defines the time slot between the received PSFCH and the corresponding PSFCH feedback. PSFCH resources may support cyclic shift pairs for PSFCH transmission, where the number of cyclic shift pairs corresponds to {1,2,3,4,6}. Generally, PSFCH resources can be (pre)configured using the rbSetPSFCH bitmap (e.g., carried in configuration signaling).

[0094] In some wireless communication systems, sidelink communication includes the transmission of signaling messages in SCI-1, SCI-2, and PSSCH. SC1-1 is transmitted via PSSCH and identifies at least a portion of the information associated with SC1-2 and the corresponding PSSCH data transmission scheduled by SC1-1. SCI-2 is transmitted via PSSCH and indicates the final scheduling / parameter information for the corresponding PSSCH data transmission. SCI-1 and SCI-2 are typically considered as two parts of the SCI used for sidelink communication (e.g., one SCI is broken down into two parts) and are associated with or otherwise linked to the corresponding PSSCH data transmission. Accordingly, SCI and PSSCH are typically associated with each other and transmitted together.

[0095] However, such wireless communication systems do not provide any mechanism for autonomous SCI transmission. This prevents sidelink devices from transmitting autonomous sidelink control signaling via the sidelink channel. That is, such wireless communication systems would require a sidelink device with sidelink control signaling (e.g., sidelink communication) to transmit SCI-1 and SCI-2, which schedule PSSCH data transmission. Subsequently, the sidelink device would transmit its sidelink control signaling via PSSCH data transmission. This technique is inefficient and wasteful when the sidelink device only has the sidelink control signaling to send (e.g., a small data payload).

[0096] Accordingly, the described aspects of the techniques provide various mechanisms to support scheduling or otherwise allocating at least a portion of PSFCH resources for inter-UE sidelink communication. In some aspects, these techniques may utilize a self-contained SCI format transmitted on PSFCH resources for inter-UE coordination, scheduling request (SR) transmission, spatial reuse parameter signaling, resource release signaling, etc., supporting sidelink communication between UEs.

[0097] In some aspects, this may include sidelink UEs performing sidelink communication via a sidelink channel (e.g., PSCCH transmission for SCI-1 and PSSCH transmission for SCI-2, and corresponding PSSCH data communication). For example, the transmitting device may transmit or otherwise provide sidelink communication to the receiving device via the sidelink channel. The receiving device may respond by transmitting or otherwise providing a feedback message to the transmitting device via the PSFCH using a first resource configuration. In some examples, the first resource configuration may correspond to legacy PSFCH resources configured for the last two symbols of a time slot (e.g., two symbols preceding the gap period allocated to the last symbol of the time slot). In this case, the feedback message may be used for sidelink communication (e.g., ACK / NACK feedback information may be delivered for PSCCH and / or PSSCH transmissions).

[0098] However, a second resource configuration of PSFCH resources, such as time, frequency, space, and code, can be identified, scheduled, allocated, or otherwise associated with sidelink communication via PSFCH. That is, a second resource configuration of PSFCH resources can provide additional PSFCH resources to support inter-UE coordination of sidelink control signaling between sidelink UEs. The second resource configuration may exclude resources from the first resource configuration (e.g., legacy PSFCH resources allocated to the last two symbols of some time slots), include some resources from the first resource configuration, or include all resources from the first resource configuration.

[0099] This may include a shared resource pool configured for sidelink control signaling messages using long-format PSFCH (e.g., in some examples, resources of a second resource configuration may be shared). Short-format PSFCH may still be used for HARQ feedback (e.g., the first resource configuration may be used for feedback message transmission). Resources of the second resource configuration may be scheduled, allocated, or otherwise identified on an optional basis. That is, the second resource configuration for inter-UE coordination may be scheduled, allocated, or otherwise identified based on periodic scheduling (e.g., always available) and / or as needed (e.g., based on requests for such resources from one or more sidelink devices). Accordingly, a second subset of long-format PSFCH resources may be scheduled, allocated, or otherwise identified and used to transmit sidelink control signaling messages (e.g., inter-UE coordination, or more generally, sidelink communication).

[0100] In some examples, the resources used for the second resource configuration of the PSFCH can be configured using RRC signaling, MAC control element (CE) signaling, DCI signaling, etc. For example, the transmitting and / or receiving devices can transmit / receive signals configuring the second resource configuration from any other device or any other sidelink UE and / or base station. In examples where the transmitting and / or receiving devices act as scheduling devices for sidelink communication, either device can schedule, allocate, or otherwise identify the resources used for the second resource configuration of the PSFCH. In this case, the transmitting and / or receiving devices can transmit signals configuring the second resource configuration to other devices and / or other sidelink devices.

[0101] Additionally or alternatively, the resources for the second resource configuration of the PSFCH can be configured on a per-resource-pool basis. For example, the resources for the PSFCH in the second resource configuration can be associated with a resource pool that includes persistent or semi-persistent resources available for sidelink communication. In another example, the resources for the PSFCH in the second resource configuration can be associated with a resource pool that includes dynamically scheduled resources available for sidelink communication.

[0102] In some examples, the resources of the PSFCH used for the second resource configuration may be available only to receiving devices. That is, only receiving devices on the sidelink channel (e.g., UEs receiving sidelink transmissions during a specific time slot) are allowed to access the second resource configuration to transmit such sidelink control signaling messages. Examples of sidelink communication using the resources of the PSFCH in the second resource configuration, as discussed above, can be used for inter-UE coordination, SR transmission, spatial reuse parameter signaling, resource release signaling, etc. (e.g., sidelink control signaling).

[0103] In some respects, HARQ feedback signaling can be transmitted separately from sidelink communication, or it can be multiplexed with sidelink communication and transmitted via a second resource configuration of the PSFCH. That is, in some examples, the receiving device can multiplex the feedback message with sidelink communication transmitted via the PSFCH. In other examples, the receiving device can transmit the feedback message separately from the sidelink communication transmitted via the PSFCH.

[0104] In some aspects, the transmitting device may schedule, allocate, or otherwise identify resources for the PSFCH used in the second resource configuration in a multicast scenario. In a unicast scenario, the receiving device may transmit on the second resource configuration independently (e.g., alone) or on behalf of the transmitting device (e.g., signaling resource release). A non-limiting example use case for such techniques may include the receiving device repeatedly (e.g., relaying) resource reservations in SCI-1 for other sidelink devices that are unable to decode SCI-1 due to half-duplex operation, interference, collisions, etc. In some examples, other sidelink devices may attempt to blindly decode the second resource configuration to detect such inter-UE coordination.

[0105] In some aspects, sidelink communication performed using a second resource configuration may be associated with a specific format. In one example, this may include using a format similar to SCI-1 and / or SCI-2 (e.g., similar or identical number of resource blocks, MCS, etc.). In some examples, the first symbol of the PSFCH resource in the second resource configuration may be used for automatic gain control (AGC). In some examples, the PSFCH resource in the second resource configuration may be limited to a single subchannel, may span multiple subchannels, or may span all subchannels in the frequency band used for sidelink communication. In some examples involving unicast transmission types where the PSFCH spans multiple subchannels, the receiving device may transmit one signaling message in each subchannel (e.g., repeating the same signaling message in each subchannel and / or transmitting different signaling messages in different subchannels). In some examples involving multicast transmission types where the PSFCH spans multiple subchannels, the transmitting device may schedule, allocate, or otherwise identify the PSFCH resource for the second resource configuration for multicast transmission.

[0106] In some examples, the transmitting device, receiving device, or any other sidelink device may access resources of the PSFCH in the second resource configuration (e.g., a shareable resource pool). In this case, the receiving device may monitor the second resource configuration to receive sidelink communication from the transmitting device, base station, or any other sidelink device via the PSFCH. In some aspects, if the transmitting device does not expect to receive HARQ feedback and / or sidelink communication in the resources of the PSFCH in the second resource configuration, the transmitting device may use those resources to transmit inter-UE coordination (e.g., sidelink control signaling).

[0107] In some examples, this may include both the transmitting and receiving devices simultaneously using the second resource configuration to perform sidelink communication transmissions. For example, the transmitting and receiving devices may determine that the second resource configuration is available and therefore use the resources of the PSFCH in the second resource configuration to perform inter-UE coordination. In some aspects, the transmitting device may transmit or otherwise provide (e.g., in SCI-1 and / or SCI-2) an indication that it intends to use the resources of the PSFCH in the second resource configuration to transmit sidelink communication. In some examples, the receiving device may decide to use the second resource configuration to transmit sidelink communication (such as when sidelink communication is transmitted to different sidelink devices and using different resources of the second resource configuration). In some examples, upon receiving an indication that the transmitting device (or some other sidelink device) will use the second resource configuration to perform sidelink communication, the receiving device may postpone its transmission of sidelink communication using the second resource configuration. In some examples, the receiving device may (e.g., using SCI) transmit an indication of its intention to perform sidelink communication via the sidelink feedback channel (e.g., indicating to other sidelink devices that it intends to utilize the resources of the PSFCH in the second resource configuration).

[0108] In some examples, the transmitting device may configure the receiving device to skip / delay sidelink control signaling transmissions in certain time slots (such as the time slots where the transmitting device intends to transmit its own sidelink control signaling). For example, the transmitting device may use SCI-1 and / or SCI-2 to transmit or otherwise provide instructions regarding which time slots the receiving device intends to skip sidelink control signaling transmissions. In this case, the transmitting device may perform sidelink control signaling transmissions using all or some of the resources in a second resource configuration. In some cases, sidelink control signaling transmissions may be performed on behalf of the receiving device (e.g., by the transmitting device).

[0109] In some examples, the resources of the PSFCH in the second resource configuration can be contention-free resources, allowing sidelink devices to transmit sidelink communications via the PSFCH based on contention-free channel access procedures. For example, the second resource configuration may include resource allocations configured by the transmitting device, the base station managing sidelink communications, and / or some other sidelink device. In some aspects, SC1-1, SC1-2, and / or other signaling techniques (e.g., upper-layer signaling) may be used to provide indications about the availability and / or otherwise allocation of the second resource configuration. In some examples, the resources of the PSFCH in the second resource configuration may use contention-based access. For example, in this case, any sidelink device may access the second resource configuration for sidelink control signaling after performing channel access procedures (e.g., Open Channel Assessment (CCA), Listen-Before-Talk (LBT), etc.). In one example, this may include a best-effort delivery of the second resource configuration using random access for each sidelink device to obtain (e.g., to access) the second resource configuration. In another example, the transmitting device may perform signal strength measurements in the resources(s) of the second resource configuration. If the measured signal strength is less than a threshold (e.g., the threshold is met), the transmitting device may access the channel after a random backoff time. If the measured signal strength is greater than the threshold (e.g., the threshold is not met), the transmitting device may determine that the channel is busy and therefore wait for a period of time before attempting another channel access procedure. In some examples, the transmitting device may monitor resources(s) of a second resource configuration to detect collisions. The transmitting device may adjust its channel access based on the detected collisions(s) (e.g., if the collision rate is high, a larger backoff may be used).

[0110] In another example, this could include a first-come-first-served scenario based on an indication (e.g., sidelink control signaling) that another sidelink device intends to perform sidelink communication. For example, any sidelink device could monitor selected subchannels or transmission indications in each subchannel from other sidelink devices. If a sidelink device determines that a channel is occupied (e.g., receiving an indication that another sidelink device will use a second resource configuration for transmission), it can back off and wait to perform its sidelink communication. If a sidelink device determines that the second resource configuration is not occupied, it can wait for a number of symbols and / or time slots and then transmit its own indication that it will use the second resource configuration to perform sidelink communication. After transmitting its indication of intention to transmit, the sidelink device can access the channel in the current symbol / time slot and / or subsequent symbol / time slots. In some examples, the selection of subchannels for sidelink communication transmission using the second resource configuration can be based on various factors such as available subchannels, the identifier of the sidelink device, UE capabilities, etc. In some examples, the indication that the sidelink device will use the second resource configuration for transmission may carry or otherwise convey an indication of how long the sidelink device intends to occupy the channel (for example, an indication of the amount of data to be transmitted, the amount of subchannels to be used for transmission, the amount of symbols / time slots to be used for transmission, etc.).

[0111] In some examples, reservations for the second resource configuration may be based on SC1-1 and / or SC1-2. For example, a reservation (e.g., a transmission indicating that a sidelink device will use the second resource configuration for transmission) may occur before transmission in SCI-1 and / or SCI-2 (e.g., using the new SCI-2 format). In this case, other sidelink devices attempting to use the second resource configuration may decode the other sidelink device's SCI-2 messages to identify or otherwise determine the reservations.

[0112] In some respects, a hybrid or combination of the examples discussed above can be used. That is, time slots occupied / reserved by a sidelink device (e.g., based on an indication of its intention to transmit) can use contention-free channel access, while time slots not occupied by a sidelink device (e.g., without any indication of intention to transmit) can use a contention-based channel access procedure. Accordingly, in a contention-free access procedure scenario, the sidelink device can transmit sidelink communication using a second resource configuration of the PSFCH after transmitting an indication of its intention to transmit. In a contention-based channel access procedure (e.g., a CCA procedure), the sidelink device can perform a CCA procedure on the resources of the PSFCH in the second resource configuration and perform sidelink communication via the PSFCH based on the result of the CCA procedure.

[0113] Figure 3 Examples of feedback configuration 300 supporting sidelink feedback channel signaling in a new radio sidelink, according to various aspects of this disclosure, are described. Feedback configuration 300 can implement various aspects of wireless communication systems 100 and / or 200. Various aspects of feedback configuration 300 can be implemented by or at a UE, which can be an example of the corresponding device described herein (e.g., a transmitting device, a receiving device, or more generally, a sidelink device).

[0114] As discussed above, the described aspects of the technology provide a transmitting device with the ability to transmit sidelink communication to a receiving device via a sidelink channel (e.g., PSCCH and PSSCH communication). Sidelink communication may include SCI-1 transmitted via PSCCH, SCI-2 transmitted via PSSCH, and a data payload transmitted via PSSCH. Sidelink communication may be transmitted on one or more time slots 305, with four time slots 305 shown only by way of example. The receiving device may use a first resource configuration (explained as PSFCH for HARQ 310) to transmit or otherwise provide feedback messages to the transmitting device via a sidelink feedback channel (e.g., PSFCH). As discussed above, the PSFCH for HARQ 310 (e.g., the first resource configuration) is typically configured as the last two symbols of time slot 305 (technically, the last symbol of time slot 305 may be reserved as a gap period to allow the sidelink device to perform a transmit-to-receive transition, or vice versa). Accordingly, the gap symbol can occupy the last symbol of time slot 305, and the PSFCH used for HARQ 310 can occupy the first two symbols of time slot 305.

[0115] The transmitting and / or receiving devices may identify or otherwise determine a second resource configuration (interpreted as PSFCH for signaling 315) of the PSFCH that is scheduled, allocated, or otherwise associated with sidelink communication (e.g., sidelink control signaling) via the PSFCH. For example, the second resource configuration may be configured by a scheduling device (such as a transmitting device, base station, etc.) within the sidelink network. In some examples, the second resource configuration may be associated with a specific resource pool configuration. Accordingly, the receiving and / or transmitting devices may use the second resource configuration (e.g., PSFCH for signaling 315) to perform sidelink communication (e.g., sidelink control signaling) via the PSFCH.

[0116] In a non-limiting example illustrated in feedback configuration 300, this may include a first resource configuration (e.g., PSFCH for HARQ 310) configured in first time slots 305-a, 305-b, 305-c, and 305-d (e.g., each time slot 305), although the PSFCH for HARQ 310 may not always be configured for each time slot 305. The first resource configuration may be configured for two symbols in time slots 305-a and 305-c, and for each of these two time slots, may span the entire frequency band used for sidelink communication (e.g., each sub-channel). The first resource configuration may be configured for three symbols in time slots 305-b and 305-d, and for each of these two time slots, may span a subset of sub-channels across the entire frequency band. Accordingly, the receiving device may transmit a feedback message to the transmitting device during one or more time slots 305 using a first resource configuration (e.g., PSFCH for HARQ 310).

[0117] In a non-limiting example illustrated in feedback configuration 300, this may include a second resource configuration (e.g., PSFCH for signaling 315) configured during the three symbol periods of time slots 305-b and 305-d, and for each of these two time slots, it may span a subset of subchannels across the entire frequency band. Accordingly, the receiving device may use the second resource configuration (e.g., PSFCH for signaling 315) to transmit sidelink communication (e.g., sidelink control signaling) to the transmitting device (and / or some other sidelink devices). In some examples, the sidelink communication performed using the second resource configuration may use an SCI-type format (e.g., similar to the format used for SCI-1 and / or SCI-2).

[0118] Figure 4 Examples of feedback configuration 400 supporting sidelink feedback channel signaling in a new radio sidelink, according to various aspects of this disclosure, are described. Feedback configuration 400 may implement aspects of wireless communication systems 100 and / or 200 and / or feedback configuration 300. Aspects of feedback configuration 400 may be implemented by or at a UE, which may be an example of the corresponding device described herein (e.g., a transmitting device, a receiving device, or more generally, a sidelink device).

[0119] As discussed above, the described aspects of the technology provide a transmitting device with the ability to transmit sidelink communication to a receiving device via a sidelink channel (e.g., PSCCH and PSSCH communication). Sidelink communication may include SCI-1 transmitted via PSCCH, SCI-2 transmitted via PSSCH, and a data payload transmitted via PSSCH. Sidelink communication may be transmitted on one or more time slots 405, of which four time slots 405 are shown by way of example only. The receiving device may use a first resource configuration (explained as PSFCH for HARQ 410) to transmit or otherwise provide feedback messages to the transmitting device via a sidelink feedback channel (e.g., PSFCH). As discussed above, the PSFCH for HARQ 410 (e.g., the first resource configuration) is typically configured as the last two symbols of time slot 405 (technically, the last symbol of time slot 405 may be reserved as a gap period to allow the sidelink device to perform a transmit-to-receive transition, or vice versa). Accordingly, the gap symbol can occupy the last symbol of time slot 405, and the PSFCH used for HARQ 410 can occupy the first two symbols of time slot 405.

[0120] The transmitting and / or receiving devices may identify or otherwise determine a second resource configuration (interpreted as PSFCH for signaling 415) of the PSFCH that is scheduled, allocated, or otherwise associated with sidelink communication (e.g., sidelink control signaling) via the PSFCH. For example, the second resource configuration may be configured by a scheduling device (such as a transmitting device, base station, etc.) within the sidelink network. In some examples, the second resource configuration may be associated with a specific resource pool configuration. Accordingly, the receiving and / or transmitting devices may use the second resource configuration (e.g., PSFCH for signaling 415) to perform sidelink communication (e.g., sidelink control signaling) via the PSFCH.

[0121] In a non-limiting example illustrated in feedback configuration 400, this may include a first resource configuration (e.g., PSFCH for HARQ 410) configured in first time slots 405-a, 405-b, 405-c, and 405-d (e.g., each time slot 405), although the PSFCH for HARQ 410 may not always be configured for each time slot 405. The first resource configuration may be configured for two symbols in time slots 405-a and 405-c, and for each of these two time slots, may span the entire frequency band used for sidelink communication (e.g., each sub-channel). The first resource configuration may be configured for three symbols in time slots 405-b and 405-d, and for each of these two time slots, may span a subset of sub-channels in the entire frequency band. Accordingly, the receiving device may transmit a feedback message to the transmitting device during one or more time slots 405 using a first resource configuration (e.g., PSFCH for HARQ 410).

[0122] In a non-limiting example illustrated in feedback configuration 400, this may include a second resource configuration (e.g., PSFCH for signaling 415) configured during the three symbol periods of time slots 405-b and 405-d, and for each of these two time slots, may span a subset of subchannels across the entire frequency band. Accordingly, the receiving device may use the second resource configuration (e.g., PSFCH for signaling 415) to transmit sidelink communication (e.g., sidelink control signaling) to the transmitting device (and / or some other sidelink device). In some examples, the sidelink communication performed using the second resource configuration may use an SCI-type format (e.g., similar to the format used for SCI-1 and / or SCI-2).

[0123] As discussed above, in some examples, a sidelink device (e.g., a transmitting device, a receiving device, or any other sidelink device) may transmit an instruction that it intends to perform sidelink communication using a second resource configuration of the PSFCH (e.g., using the PSFCH for signaling 415). Figure 4 In the non-limiting example described herein, this may include certain resources used for transmitting indications (e.g., illustrated as transmission indication 420). That is, in this example, a set of resources (e.g., a second resource configuration, a first resource configuration, or a subset of other resources) may be reserved or otherwise identified as resources that a sidelink device wishing to perform sidelink communication using the second resource configuration can monitor in order to determine the availability of the second resource configuration. These resources may also be used by the sidelink device wishing to perform sidelink communication to transmit indications of what it intends to transmit. Figure 4In the non-limiting example shown, the resources used for transmitting indication 420 may be scheduled, allocated, or otherwise identified for three symbols and a subchannel for time slots 405-b and 405-d, although other configurations may be used.

[0124] Figure 5 A block diagram 500 of an apparatus 505 supporting sidelink feedback channel signaling in a new radio sidelink according to various aspects of this disclosure is shown. Apparatus 505 may be an example of various aspects of UE 115 as described herein. Apparatus 505 may include a receiver 510, a transmitter 515, and a communications manager 520. Apparatus 505 may also include a processor. Each of these components may be in communication with each other (e.g., via one or more buses).

[0125] Receiver 510 may provide means for receiving information, such as packets, user data, control information, or any combination thereof, associated with various information channels (e.g., control channels, data channels, information channels related to sidelink feedback channel signaling in new radio sidelinks). The information may be transmitted to other components of device 505. Receiver 510 may utilize a single antenna or a collection of multiple antennas.

[0126] Transmitter 515 may provide means for transmitting signals generated by other components of device 505. For example, transmitter 515 may transmit information such as packets, user data, control information, or any combination thereof associated with various information channels (e.g., control channels, data channels, information channels related to sidelink feedback channel signaling in new radio sidelinks). In some examples, transmitter 515 may be co-located with receiver 510 in a transceiver module. Transmitter 515 may utilize a single antenna or a collection of multiple antennas.

[0127] Communication manager 520, receiver 510, transmitter 515, or various combinations thereof, or various components thereof, may be examples of means for performing various aspects of sidelink feedback channel signaling in a novel radio sidelink as described herein. For example, communication manager 520, receiver 510, transmitter 515, or various combinations thereof, or components thereof, may support methods for performing one or more functions described herein.

[0128] In some examples, the communication manager 520, receiver 510, transmitter 515, or various combinations or components thereof may be implemented in hardware (e.g., in a communication management circuitry system). This hardware may include a processor, digital signal processor (DSP), application-specific integrated circuit (ASIC), field-programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof, configured to or otherwise support means for performing the functions described herein. In some examples, the processor and memory coupled to the processor may be configured to perform one or more functions described herein (e.g., by executing instructions stored in memory by the processor).

[0129] Additionally or alternatively, in some examples, the communication manager 520, receiver 510, transmitter 515, or various combinations or components thereof may be implemented by code executed by a processor (e.g., as communication management software or firmware). If implemented in code executed by a processor, the functionality of the communication manager 520, receiver 510, transmitter 515, or various combinations or components thereof may be performed by a general-purpose processor, DSP, central processing unit (CPU), ASIC, FPGA, or any combination of these or other programmable logic devices (e.g., means configured or otherwise supported for performing the functions described in this disclosure).

[0130] In some examples, the communication manager 520 may be configured to use or otherwise cooperate with the receiver 510, transmitter 515, or both to perform various operations (e.g., receiving, monitoring, transmitting). For example, the communication manager 520 may receive information from the receiver 510, send information to the transmitter 515, or be integrated with the receiver 510, transmitter 515, or both to receive information, transmit information, or perform various other operations described herein.

[0131] Communication manager 520 may support wireless communication at a first UE according to examples disclosed herein. For example, communication manager 520 may be configured or otherwise support means for receiving sidelink communication from a second UE via a sidelink channel. Communication manager 520 may be configured or otherwise support means for transmitting a feedback message to the second UE via a sidelink feedback channel using a first resource configuration, the feedback message being based on the sidelink communication. Communication manager 520 may be configured or otherwise support means for identifying a second resource configuration of a sidelink feedback channel associated with inter-UE communication via the sidelink feedback channel. Communication manager 520 may be configured or otherwise support means for performing inter-UE communication with the second UE via the sidelink feedback channel using the second resource configuration of the sidelink feedback channel.

[0132] Additionally or alternatively, the communication manager 520 may support wireless communication at the first UE according to the examples disclosed herein. For example, the communication manager 520 may be configured or otherwise support means for transmitting sidelink communication to a second UE via a sidelink channel. The communication manager 520 may be configured or otherwise support means for receiving a feedback message from the second UE via a sidelink feedback channel using a first resource configuration, the feedback message being based on the sidelink communication. The communication manager 520 may be configured or otherwise support means for identifying a second resource configuration of the sidelink feedback channel associated with inter-UE communication via the sidelink feedback channel. The communication manager 520 may be configured or otherwise support means for performing inter-UE communication with the second UE via the sidelink feedback channel using the second resource configuration of the sidelink feedback channel.

[0133] By including or configuring a communication manager 520 according to an example as described herein, device 505 (e.g., a processor that controls or is otherwise coupled to receiver 515, transmitter 520, communication manager 1220, or a combination thereof) can support techniques for utilizing PSSCH resources reallocated to PSFCH resources to support sidelink control signaling via PSFCH resources. This enables independent SCI transmission within the sidelink network, rather than SCI transmission linked to PSSCH sidelink data transmission. This can improve sidelink resource utilization and efficiency.

[0134] Figure 6 A block diagram 600 of an apparatus 605 supporting sidelink feedback channel signaling in a new radio sidelink is shown according to aspects of this disclosure. Apparatus 605 may be an example of aspects of apparatus 505 or UE 115 as described herein. Apparatus 605 may include a receiver 610, a transmitter 615, and a communications manager 620. Apparatus 605 may also include a processor. Each of these components may be in communication with each other (e.g., via one or more buses).

[0135] Receiver 610 may provide means for receiving information, such as packets, user data, control information, or any combination thereof, associated with various information channels (e.g., control channels, data channels, information channels related to sidelink feedback channel signaling in new radio sidelinks). The information may be transmitted to other components of device 605. Receiver 610 may utilize a single antenna or a collection of multiple antennas.

[0136] Transmitter 615 may provide means for transmitting signals generated by other components of device 605. For example, transmitter 615 may transmit information such as packets, user data, control information, or any combination thereof associated with various information channels (e.g., control channels, data channels, information channels related to sidelink feedback channel signaling in new radio sidelinks). In some examples, transmitter 615 may be co-located with receiver 610 in a transceiver module. Transmitter 615 may utilize a single antenna or a collection of multiple antennas.

[0137] Device 605 or its various components may be examples of means for performing aspects of sidelink feedback channel signaling in a novel radio sidelink as described herein. For example, communication manager 620 may include sidelink communication manager 625, feedback message manager 630, resource manager 635, sidelink control signaling manager 640, or any combination thereof. Communication manager 620 may be examples of aspects of communication manager 520 as described herein. In some examples, communication manager 620 or its various components may be configured to use or otherwise cooperate with receiver 610, transmitter 615, or both to perform various operations (e.g., receiving, monitoring, transmitting). For example, communication manager 620 may receive information from receiver 610, send information to transmitter 615, or be integrated in combination with receiver 610, transmitter 615, or both to receive information, transmit information, or perform various other operations described herein.

[0138] Communication manager 620 may support wireless communication at a first UE according to examples disclosed herein. Sidelink communication manager 625 may be configured or otherwise support means for receiving sidelink communication from a second UE via a sidelink channel. Feedback message manager 630 may be configured or otherwise support means for transmitting a feedback message to the second UE via a sidelink feedback channel using a first resource configuration, the feedback message being based on sidelink communication. Resource manager 635 may be configured or otherwise support means for identifying a second resource configuration of the sidelink feedback channel associated with inter-UE communication via the sidelink feedback channel. Sidelink control signaling manager 640 may be configured or otherwise support means for performing inter-UE communication with the second UE via the sidelink feedback channel using the second resource configuration of the sidelink feedback channel.

[0139] Additionally or alternatively, the communication manager 620 may support wireless communication at the first UE according to the examples disclosed herein. The sidelink communication manager 625 may be configured or otherwise support means for transmitting sidelink communication to the second UE via a sidelink channel. The feedback message manager 630 may be configured or otherwise support means for receiving a feedback message from the second UE via a sidelink feedback channel using a first resource configuration, the feedback message being based on the sidelink communication. The resource manager 635 may be configured or otherwise support means for identifying a second resource configuration of the sidelink feedback channel associated with inter-UE communication via the sidelink feedback channel. The sidelink control signaling manager 640 may be configured or otherwise support means for performing inter-UE communication with the second UE via the sidelink feedback channel using the second resource configuration of the sidelink feedback channel.

[0140] Figure 7 A block diagram 700 is shown of a communication manager 720 supporting sidelink feedback channel signaling in a new radio sidelink according to aspects of this disclosure. The communication manager 720 may be an example of aspects of the communication manager 520, communication manager 620, or both described herein. The communication manager 720 or its various components may be examples of means for performing aspects of sidelink feedback channel signaling in a new radio sidelink as described herein. For example, the communication manager 720 may include a sidelink communication manager 725, a feedback message manager 730, a resource manager 735, a sidelink control signaling manager 740, a sidelink communication indication manager 745, a resource configuration manager 750, a contention manager 755, a request manager 760, or any combination thereof. Each of these components may communicate directly or indirectly with each other (e.g., via one or more buses).

[0141] Communication manager 720 may support wireless communication at a first UE according to examples disclosed herein. Sidelink communication manager 725 may be configured or otherwise supported to support means for receiving sidelink communication from a second UE via a sidelink channel. Feedback message manager 730 may be configured or otherwise supported to support means for transmitting a feedback message to the second UE via a sidelink feedback channel using a first resource configuration, the feedback message being based on sidelink communication. Resource manager 735 may be configured or otherwise supported to support means for identifying a second resource configuration of the sidelink feedback channel associated with inter-UE communication via the sidelink feedback channel. Sidelink control signaling manager 740 may be configured or otherwise supported to support means for performing inter-UE communication with the second UE via the sidelink feedback channel using the second resource configuration of the sidelink feedback channel.

[0142] In some examples, the sidelink communication indication manager 745 may be configured or otherwise supported to provide means for receiving an indication from a second UE, a different UE, or both, regarding the performance of inter-UE communication via the sidelink feedback channel using a second resource configuration.

[0143] In some examples, the resource configuration manager 750 may be configured or otherwise supported as means for receiving signals configuring a second resource configuration from a second UE, a different UE, a base station, or any combination thereof.

[0144] In some examples, the sidelink manager 725 may be configured or otherwise support means for multiplexing feedback messages with communication between UEs via the sidelink feedback channel.

[0145] In some examples, the sidelink manager 725 may be configured or otherwise support means for transmitting feedback messages via the sidelink feedback channel separately from UE-to-UE communication via the sidelink feedback channel.

[0146] In some examples, in order to support the execution of inter-UE communication, the contention manager 755 may be configured or otherwise supported for means of transmitting inter-UE communication via a sidelink feedback channel based on a contention-free channel access procedure.

[0147] In some examples, to support the execution of inter-UE communication, the contention manager 755 may be configured or otherwise supported to support means for performing channel access procedures on the sidelink feedback channel. In some examples, to support the execution of inter-UE communication, the contention manager 755 may be configured or otherwise supported to support means for performing inter-UE communication via the sidelink feedback channel based on the results of the channel access procedure.

[0148] In some examples, to support the execution of inter-UE communication, the contention manager 755 may be configured or otherwise supported to monitor sidelink control information messages indicating that inter-UE communication should be performed via the sidelink feedback channel. In some examples, to support the execution of inter-UE communication, the contention manager 755 may be configured or otherwise supported to support means for performing inter-UE communication via the sidelink feedback channel based on the results of such monitoring.

[0149] In some examples, to support the execution of inter-UE communication, the request manager 760 may be configured or otherwise supported to provide means for transmitting a sidelink control information message instructing a first UE to perform inter-UE communication via a sidelink feedback channel. In some examples, to support the execution of inter-UE communication, the request manager 760 may be configured or otherwise supported to provide means for performing inter-UE communication via a sidelink feedback channel based on the sidelink control information message.

[0150] In some examples, in order to support UE-to-UE communication via the sidelink feedback channel, the sidelink communication manager 725 may be configured or otherwise support means for transmitting, receiving, or simultaneously transmitting and receiving UE-to-UE communication via the sidelink feedback channel.

[0151] Additionally or alternatively, the communication manager 720 may support wireless communication at the first UE according to the examples disclosed herein. In some examples, the sidelink manager 725 may be configured or otherwise support means for transmitting sidelink communication to the second UE via a sidelink channel. In some examples, the feedback message manager 730 may be configured or otherwise support means for receiving a feedback message from the second UE via a sidelink feedback channel using a first resource configuration, the feedback message being based on sidelink communication. In some examples, the resource manager 735 may be configured or otherwise support means for identifying a second resource configuration of the sidelink feedback channel associated with inter-UE communication via the sidelink feedback channel. In some examples, the sidelink control signaling manager 740 may be configured or otherwise support means for performing inter-UE communication with the second UE via the sidelink feedback channel using a second resource configuration of the sidelink feedback channel.

[0152] In some examples, the sidelink communication indication manager 745 may be configured or otherwise supported to provide means for transmitting an indication to a second UE, a different UE, or both, regarding the use of a second resource configuration to perform inter-UE communication via the sidelink feedback channel.

[0153] In some examples, the resource configuration manager 750 may be configured or otherwise support means for transmitting signals configuring a second resource configuration to a second UE, a different UE, a base station, or any combination thereof.

[0154] In some examples, feedback messages are multiplexed with UE-to-UE communication via the sidelink feedback channel.

[0155] In some examples, the sidelink manager 725 may be configured or otherwise supported as a means for receiving feedback messages via the sidelink feedback channel separately from UE-to-UE communication via the sidelink feedback channel.

[0156] In some examples, to support the execution of inter-UE communication, the sidelink communication manager 725 may be configured or otherwise supported for means of transmitting inter-UE communication via the sidelink feedback channel based on a contention-free channel access procedure.

[0157] In some examples, to support the execution of inter-UE communication, the contention manager 755 may be configured or otherwise supported to support means for performing channel access procedures on the sidelink feedback channel. In some examples, to support the execution of inter-UE communication, the contention manager 755 may be configured or otherwise supported to support means for performing inter-UE communication via the sidelink feedback channel based on the results of the channel access procedure.

[0158] In some examples, to support the execution of inter-UE communication, the sidelink communication indication manager 745 may be configured or otherwise supported to provide means for transmitting a sidelink control information message indicating that inter-UE communication should be performed via a sidelink feedback channel. In some examples, to support the execution of inter-UE communication, the sidelink communication indication manager 745 may be configured or otherwise supported to provide means for performing inter-UE communication via a sidelink feedback channel based on the result of the sidelink control information message.

[0159] In some examples, to support the execution of inter-UE communication, the request manager 760 may be configured or otherwise supported to receive a sidelink control information message instructing a second UE to perform inter-UE communication via a sidelink feedback channel. In some examples, to support the execution of inter-UE communication, the request manager 760 may be configured or otherwise supported to perform inter-UE communication via a sidelink feedback channel based on the sidelink control information message.

[0160] In some examples, in order to support UE-to-UE communication via the sidelink feedback channel, the sidelink communication manager 725 may be configured or otherwise support means for transmitting, receiving, or simultaneously transmitting and receiving UE-to-UE communication via the sidelink feedback channel.

[0161] Figure 8 A diagram of a system 800 including device 805 supporting sidelink feedback channel signaling in a new radio sidelink, according to various aspects of this disclosure, is shown. Device 805 may be an example of device 505, device 605, or UE 115 as described herein, or a component including device 505, device 605, or UE 115. Device 805 may wirelessly communicate with one or more base stations 105, UE 115, or any combination thereof. Device 805 may include components for bidirectional voice and data communication, including components for transmitting and receiving communications, such as a communication manager 820, an input / output (I / O) controller 810, a transceiver 815, an antenna 825, a memory 830, a code 835, and a processor 840. These components may be in electronic communication or otherwise coupled (e.g., operational ground, communication ground, functional ground, electronic ground, electrical ground) via one or more buses (e.g., bus 845).

[0162] I / O controller 810 manages the input and output signals of device 805. I / O controller 810 can also manage peripheral devices not integrated into device 805. In some cases, I / O controller 810 may represent a physical connection or port to an external peripheral device. In some cases, I / O controller 810 may utilize an operating system, such as... Or another known operating system. Additionally or alternatively, the I / O controller 810 may represent or interact with a modem, keyboard, mouse, touchscreen, or similar device. In some cases, the I / O controller 810 may be implemented as part of a processor (such as processor 840). In some cases, a user may interact with device 805 via the I / O controller 810 or via hardware components controlled by the I / O controller 810.

[0163] In some cases, device 805 may include a single antenna 825. However, in other cases, device 805 may have more than one antenna 825, which may be capable of transmitting or receiving multiple wireless transmissions concurrently. Transceiver 815 may communicate bidirectionally via one or more antennas 825, wired or wireless links, as described herein. For example, transceiver 815 may represent a wireless transceiver and be capable of bidirectional communication with another wireless transceiver. Transceiver 815 may also include a modem for modulating packets and providing modulated packets to one or more antennas 825 for transmission, and for demodulating packets received from one or more antennas 825. Transceiver 815, or transceiver 815 and one or more antennas 825, may be examples of transmitter 515, transmitter 615, receiver 510, receiver 610, or any combination thereof or components thereof as described herein.

[0164] Memory 830 may include random access memory (RAM) and read-only memory (ROM). Memory 830 may store computer-readable, computer-executable code 835, including instructions that, when executed by processor 840, cause device 805 to perform the various functions described herein. Code 835 may be stored in a non-transitory computer-readable medium, such as system memory or another type of memory. In some cases, code 835 may not be directly executed by processor 840, but may cause a computer (e.g., when compiled and executed) to perform the functions described herein. In some cases, memory 830 may, in particular, include a basic I / O system (BIOS) that controls basic hardware or software operations, such as interaction with peripheral components or devices.

[0165] Processor 840 may include intelligent hardware devices (e.g., general-purpose processors, DSPs, CPUs, microcontrollers, ASICs, FPGAs, programmable logic devices, discrete gate or transistor logic components, discrete hardware components, or any combination thereof). In some cases, processor 840 may be configured to use a memory controller to operate a memory array. In other cases, the memory controller may be integrated into processor 840. Processor 840 may be configured to execute computer-readable instructions stored in memory (e.g., memory 830) to cause device 805 to perform various functions (e.g., functions or tasks supporting sidelink feedback channel signaling in a new radio sidelink). For example, device 805 or components thereof may include processor 840 and memory 830 coupled to processor 840, wherein processor 840 and memory 830 are configured to perform the various functions described herein.

[0166] The communication manager 820 may support wireless communication at a first UE according to examples disclosed herein. For example, the communication manager 820 may be configured or otherwise support means for receiving sidelink communication from a second UE via a sidelink channel. The communication manager 820 may be configured or otherwise support means for transmitting a feedback message to the second UE via a sidelink feedback channel using a first resource configuration based on the sidelink communication. The communication manager 820 may be configured or otherwise support means for identifying a second resource configuration of the sidelink feedback channel associated with inter-UE communication via the sidelink feedback channel. The communication manager 820 may be configured or otherwise support means for performing inter-UE communication with the second UE via the sidelink feedback channel using the second resource configuration of the sidelink feedback channel.

[0167] Additionally or alternatively, the communication manager 820 may support wireless communication at a first UE according to the examples disclosed herein. For example, the communication manager 820 may be configured or otherwise support means for transmitting sidelink communication to a second UE via a sidelink channel. The communication manager 820 may be configured or otherwise support means for receiving a feedback message from the second UE via a sidelink feedback channel using a first resource configuration, the feedback message being based on the sidelink communication. The communication manager 820 may be configured or otherwise support means for identifying a second resource configuration of the sidelink feedback channel associated with inter-UE communication via the sidelink feedback channel. The communication manager 820 may be configured or otherwise support means for performing inter-UE communication with the second UE via the sidelink feedback channel using the second resource configuration of the sidelink feedback channel.

[0168] By including or configuring a communication manager 820 according to an example as described herein, device 805 can support techniques for utilizing PSSCH resources that have been reassigned to PSFCH resources to support sidelink control signaling via PSFCH resources. This enables independent SCI transmission within the sidelink network, rather than SCI transmission linked to PSSCH sidelink data transmission. This can improve sidelink resource utilization and efficiency.

[0169] In some examples, the communication manager 820 may be configured to use or otherwise coordinate with the transceiver 815, one or more antennas 825, or any combination thereof to perform various operations (e.g., receiving, monitoring, transmitting). Although the communication manager 820 is described as a separate component, in some examples, one or more functions described with reference to the communication manager 820 may be supported or executed by the processor 840, memory 830, code 835, or any combination thereof. For example, code 835 may include instructions that can be executed by the processor 840 to cause the device 805 to perform various aspects of sidelink feedback channel signaling in the novel radio sidelink as described herein, or the processor 840 and memory 830 may be otherwise configured to perform or support such operations.

[0170] Figure 9 A flowchart illustrating a method 900 for supporting sidelink feedback channel signaling in a new radio sidelink according to various aspects of this disclosure is shown. Operation of method 900 can be implemented by a UE or its components as described herein. For example, operation of method 900 can be performed by, as referred to... Figures 1 to 8 The UE 115 described herein is used to perform this function. In some examples, the UE can execute a set of instructions to control the functional elements of the UE to perform the described function. Additionally or alternatively, the UE may use dedicated hardware to perform aspects of the described function.

[0171] At 905, the method may include receiving sidelink communication from a second UE via a sidelink channel. Operation of 905 may be performed according to examples as disclosed herein. In some examples, aspects of operation of 905 may be provided by reference to... Figure 7 The sidelink communication manager 725 described is used to perform this.

[0172] At 910, the method may include transmitting a feedback message to a second UE via a sidelink feedback channel using a first resource configuration, the feedback message being based on sidelink communication. The operation of 910 may be performed according to the examples disclosed herein. In some examples, aspects of the operation of 910 may be provided by reference to... Figure 7 The feedback message manager 730 described is used to execute this.

[0173] At 915, the method may include a second resource configuration identifying the sidelink feedback channel associated with inter-UE communication via the sidelink feedback channel. Operation of 915 may be performed according to examples as disclosed herein. In some examples, aspects of operation of 915 may be determined by reference to... Figure 7 The described resource manager 735 is used to execute this.

[0174] At 920, the method may include performing inter-UE communication with a second UE via a sidelink feedback channel using a second resource configuration that utilizes the sidelink feedback channel. The operation of 920 may be performed according to examples as disclosed herein. In some examples, aspects of the operation of 920 may be provided by reference to... Figure 7 The side link control signaling manager 740 described is used to perform this.

[0175] Figure 10 A flowchart illustrating a method 1000 for supporting sidelink feedback channel signaling in a new radio sidelink according to various aspects of this disclosure is shown. Operation of method 1000 can be implemented by a UE or its components as described herein. For example, operation of method 1000 can be implemented by, as referred to... Figures 1 to 8 The UE 115 described herein is used to perform this function. In some examples, the UE can execute a set of instructions to control the functional elements of the UE to perform the described function. Additionally or alternatively, the UE may use dedicated hardware to perform aspects of the described function.

[0176] At point 1005, the method may include receiving sidelink communication from a second UE via a sidelink channel. Operation of point 1005 may be performed according to examples as disclosed herein. In some examples, aspects of operation of point 1005 may be provided by reference to... Figure 7 The sidelink communication manager 725 described is used to perform this.

[0177] At point 1010, the method may include transmitting a feedback message to a second UE via a sidelink feedback channel using a first resource configuration, the feedback message being based on sidelink communication. The operation of point 1010 may be performed according to examples as disclosed herein. In some examples, aspects of the operation of point 1010 may be provided by reference to... Figure 7 The feedback message manager 730 described is used to execute this.

[0178] At 1015, the method may include a second resource configuration identifying the sidelink feedback channel associated with inter-UE communication via the sidelink feedback channel. Operation of 1015 may be performed according to examples as disclosed herein. In some examples, aspects of operation of 1015 may be determined by reference to... Figure 7 The described resource manager 735 is used to execute this.

[0179] At 1020, the method may include receiving an indication from a second UE, a different UE, or both, regarding performing inter-UE communication via a sidelink feedback channel using a second resource configuration. The operation of 1020 may be performed according to examples as disclosed herein. In some examples, aspects of the operation of 1020 may be provided by reference to... Figure 7 The sidelink communication instruction manager 745 is described and executed accordingly.

[0180] At 1025, the method may include performing inter-UE communication with a second UE via a sidelink feedback channel using a second resource configuration that utilizes the sidelink feedback channel. The operation of 1025 may be performed according to examples as disclosed herein. In some examples, aspects of the operation of 1025 may be as described in reference... Figure 7 The side link control signaling manager 740 described is used to perform this.

[0181] Figure 11 A flowchart illustrating a method 1100 for supporting sidelink feedback channel signaling in a new radio sidelink according to various aspects of this disclosure is shown. Operation of method 1100 can be implemented by a UE or its components as described herein. For example, operation of method 1100 can be implemented by, as referred to... Figures 1 to 8 The UE 115 described herein is used to perform this function. In some examples, the UE can execute a set of instructions to control the functional elements of the UE to perform the described function. Additionally or alternatively, the UE may use dedicated hardware to perform aspects of the described function.

[0182] At 1105, the method may include receiving sidelink communication from a second UE via a sidelink channel. Operation of 1105 may be performed according to examples as disclosed herein. In some examples, aspects of operation of 1105 may be provided by reference to... Figure 7 The sidelink communication manager 725 described is used to perform this.

[0183] At 1110, the method may include transmitting a feedback message to a second UE via a sidelink feedback channel using a first resource configuration, the feedback message being based on sidelink communication. The operation of 1110 may be performed according to examples as disclosed herein. In some examples, aspects of the operation of 1110 may be provided by reference to... Figure 7 The feedback message manager 730 described is used to execute this.

[0184] At 1115, the method may include receiving a signal configuring a second resource configuration from a second UE, a different UE, a base station, or any combination thereof. Operation of 1115 may be performed according to examples disclosed herein. In some examples, aspects of operation of 1115 may be provided by reference to... Figure 7 The described Resource Configuration Manager 750 is used to execute this.

[0185] At 1120, the method may include a second resource configuration identifying the sidelink feedback channel associated with inter-UE communication via the sidelink feedback channel. Operation of 1120 may be performed according to examples as disclosed herein. In some examples, aspects of the operation of 1120 may be determined by reference to... Figure 7 The described resource manager 735 is used to execute this.

[0186] At 1125, the method may include performing inter-UE communication with a second UE via a sidelink feedback channel using a second resource configuration that utilizes the sidelink feedback channel. The operation of 1125 may be performed according to examples as disclosed herein. In some examples, aspects of the operation of 1125 may be provided by reference to... Figure 7 The side link control signaling manager 740 described is used to perform this.

[0187] Figure 12 A flowchart illustrating a method 1200 for supporting sidelink feedback channel signaling in a new radio sidelink according to various aspects of this disclosure is shown. Operation of method 1200 can be implemented by a UE or its components as described herein. For example, operation of method 1200 can be implemented by, as referred to... Figures 1 to 8 The UE 115 described herein is used to perform this function. In some examples, the UE can execute a set of instructions to control the functional elements of the UE to perform the described function. Additionally or alternatively, the UE may use dedicated hardware to perform aspects of the described function.

[0188] At 1205, the method may include transmitting sidelink communication to a second UE via a sidelink channel. The operation of 1205 may be performed according to examples as disclosed herein. In some examples, aspects of the operation of 1205 may be provided by reference to... Figure 7 The sidelink communication manager 725 described is used to perform this.

[0189] At 1210, the method may include receiving a feedback message from a second UE via a sidelink feedback channel using a first resource configuration, the feedback message being based on sidelink communication. The operation of 1210 may be performed according to examples as disclosed herein. In some examples, aspects of the operation of 1210 may be provided by reference to... Figure 7 The feedback message manager 730 described is used to execute this.

[0190] At 1215, the method may include a second resource configuration identifying the sidelink feedback channel associated with inter-UE communication via the sidelink feedback channel. Operation of 1215 may be performed according to examples as disclosed herein. In some examples, aspects of operation of 1215 may be determined by reference to... Figure 7 The described resource manager 735 is used to execute this.

[0191] At 1220, the method may include performing inter-UE communication with a second UE via a sidelink feedback channel using a second resource configuration that utilizes the sidelink feedback channel. The operation of 1220 may be performed according to examples as disclosed herein. In some examples, aspects of the operation of 1220 may be provided by reference to... Figure 7 The side link control signaling manager 740 described is used to perform this.

[0192] Figure 13 A flowchart illustrating a method 1300 for supporting sidelink feedback channel signaling in a new radio sidelink according to various aspects of this disclosure is shown. Operation of method 1300 can be implemented by a UE or its components as described herein. For example, operation of method 1300 can be implemented by, as referred to... Figures 1 to 8 The UE 115 described herein is used to perform this function. In some examples, the UE can execute a set of instructions to control the functional elements of the UE to perform the described function. Additionally or alternatively, the UE may use dedicated hardware to perform aspects of the described function.

[0193] At 1305, the method may include transmitting sidelink communication to a second UE via a sidelink channel. Operation of 1305 may be performed according to examples disclosed herein. In some examples, aspects of operation of 1305 may be provided by reference to... Figure 7 The sidelink communication manager 725 described is used to perform this.

[0194] At 1310, the method may include receiving a feedback message from a second UE via a sidelink feedback channel using a first resource configuration, the feedback message being based on sidelink communication. The operation of 1310 may be performed according to examples as disclosed herein. In some examples, aspects of the operation of 1310 may be provided by reference to... Figure 7 The feedback message manager 730 described is used to execute this.

[0195] At 1315, the method may include a second resource configuration identifying the sidelink feedback channel associated with inter-UE communication via the sidelink feedback channel. Operation of 1315 may be performed according to examples as disclosed herein. In some examples, aspects of operation of 1315 may be determined by reference to... Figure 7 The described resource manager 735 is used to execute this.

[0196] At 1320, the method may include performing inter-UE communication with a second UE via a sidelink feedback channel using a second resource configuration that utilizes the sidelink feedback channel. The operation of 1320 may be performed according to examples as disclosed herein. In some examples, aspects of the operation of 1320 may be provided by reference to... Figure 7 The side link control signaling manager 740 described is used to perform this.

[0197] At 1325, the method may include receiving feedback messages via the sidelink feedback channel separately from UE-to-UE communication via the sidelink feedback channel. Operation of 1325 may be performed according to examples as disclosed herein. In some examples, aspects of operation of 1325 may be provided by reference to... Figure 7 The sidelink communication manager 725 described is used to perform this.

[0198] The following provides an overview of the various aspects of this disclosure:

[0199] Aspect 1: A method for performing wireless communication at a first UE, comprising: receiving sidelink communication from a second UE via a sidelink channel; transmitting a feedback message to the second UE via a sidelink feedback channel using a first resource configuration, the feedback message being at least partially based on the sidelink communication; identifying a second resource configuration of the sidelink feedback channel associated with inter-UE communication via the sidelink feedback channel; and performing inter-UE communication with the second UE via the sidelink feedback channel using the second resource configuration of the sidelink feedback channel.

[0200] Aspect 2: The method of aspect 1 further includes: receiving an instruction from a second UE, a different UE, or both, regarding performing inter-UE communication via a sidelink feedback channel using a second resource configuration.

[0201] Aspect 3: The method of any one of Aspects 1 to 2 further includes: receiving a signal configuring a second resource configuration from a second UE, a different UE, a base station or any combination thereof.

[0202] Aspect 4: The method of any of Aspects 1 to 3 further includes: multiplexing the feedback message with UE-to-UE communication via the side link feedback channel.

[0203] Aspect 5: The method of any of Aspects 1 to 4 further includes: transmitting feedback messages via the sidelink feedback channel separately from UE-to-UE communication via the sidelink feedback channel.

[0204] Aspect 6: The method of any of Aspects 1 to 5, wherein performing inter-UE communication includes: transmitting inter-UE communication via a sidelink feedback channel based at least in part on a contention-free channel access procedure.

[0205] Aspect 7: The method of any of Aspects 1 to 6, wherein performing inter-UE communication includes: performing a channel access procedure on the sidelink feedback channel; and performing inter-UE communication via the sidelink feedback channel based at least in part on the result of the channel access procedure.

[0206] Aspect 8: The method of any of Aspects 1 to 7, wherein performing inter-UE communication includes: monitoring a sidelink control information message indicating that inter-UE communication should be performed via a sidelink feedback channel; and performing inter-UE communication via the sidelink feedback channel based at least in part on the result of the monitoring.

[0207] Aspect 9: A method of any of Aspects 1 to 8, wherein performing inter-UE communication includes: transmitting a sidelink control information message instructing a first UE to perform inter-UE communication via a sidelink feedback channel; and performing inter-UE communication via the sidelink feedback channel based at least in part on the sidelink control information message.

[0208] Aspect 10: The method of any of Aspects 1 to 9, wherein performing inter-UE communication via a sidelink feedback channel includes: transmitting, receiving, or simultaneously transmitting and receiving inter-UE communication via the sidelink feedback channel.

[0209] Aspect 11: A method for performing wireless communication at a first UE, comprising: transmitting sidelink communication to a second UE via a sidelink channel; receiving a feedback message from the second UE via a sidelink feedback channel using a first resource configuration, the feedback message being at least partially based on the sidelink communication; identifying a second resource configuration of the sidelink feedback channel associated with inter-UE communication via the sidelink feedback channel; and performing inter-UE communication with the second UE via the sidelink feedback channel using the second resource configuration of the sidelink feedback channel.

[0210] Aspect 12: The method of aspect 11 further includes: transmitting to a second UE, a different UE, or both an indication that inter-UE communication will be performed via a sidelink feedback channel using a second resource configuration.

[0211] Aspect 13: The method of any of Aspects 11 to 12 further includes: transmitting a signal configuring a second resource configuration to a second UE, a different UE, a base station, or any combination thereof.

[0212] Aspect 14: The method of any of Aspects 11 to 13, wherein the feedback message is multiplexed with communication between UEs via a sidelink feedback channel.

[0213] Aspect 15: The method of any of Aspects 11 to 14 further includes: receiving feedback messages via the sidelink feedback channel separately from UE-to-UE communication via the sidelink feedback channel.

[0214] Aspect 16: The method of any of Aspects 11 to 15, wherein performing inter-UE communication includes: transmitting inter-UE communication via a sidelink feedback channel based at least in part on a contention-free channel access procedure.

[0215] Aspect 17: The method of any of Aspects 11 to 16, wherein performing inter-UE communication includes: performing a channel access procedure on the sidelink feedback channel; and performing inter-UE communication via the sidelink feedback channel based at least in part on the result of the channel access procedure.

[0216] Aspect 18: A method of any of Aspects 11 to 17, wherein performing inter-UE communication includes: transmitting a sidelink control information message indicating that inter-UE communication is to be performed via a sidelink feedback channel; and performing inter-UE communication via a sidelink feedback channel based at least in part on the result of the sidelink control information message.

[0217] Aspect 19: The method of any of Aspects 11 to 18, wherein performing inter-UE communication includes: receiving a sidelink control information message instructing a second UE to perform inter-UE communication via a sidelink feedback channel; and performing inter-UE communication via the sidelink feedback channel based at least in part on the sidelink control information message.

[0218] Aspect 20: The method of any of Aspects 11 to 19, wherein performing inter-UE communication via a sidelink feedback channel includes: transmitting, receiving, or simultaneously transmitting and receiving inter-UE communication via the sidelink feedback channel.

[0219] Aspect 21: An apparatus for performing wireless communication at a first UE, comprising: a processor; a memory coupled to the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform a method as described in any of Aspects 1 to 10.

[0220] Aspect 22: An apparatus for wireless communication at a first UE, comprising at least one means for performing a method as described in any of Aspects 1 to 10.

[0221] Aspect 23: A non-transient computer-readable medium storing code for wireless communication at a first UE, the code including instructions executable by a processor to perform methods as described in any of Aspects 1 to 10.

[0222] Aspect 24: An apparatus for wireless communication at a first UE, comprising: a processor; a memory coupled to the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform a method as described in any of Aspects 11 to 20.

[0223] Aspect 25: An apparatus for wireless communication at a first UE, comprising at least one means for performing a method as described in any of Aspects 11 to 20.

[0224] Aspect 26: A non-transient computer-readable medium storing code for wireless communication at a first UE, the code including instructions executable by a processor to perform methods as described in any of Aspects 11 to 20.

[0225] It should be noted that the methods described in this paper describe possible implementations, and the operations and steps can be rearranged or otherwise modified, and other implementations are also possible. Furthermore, aspects from two or more methods can be combined.

[0226] While aspects of LTE, LTE-A, LTE-A Pro, or NR systems may be described for illustrative purposes, and the terms LTE, LTE-A, LTE-A Pro, or NR may be used in most of the description, the techniques described herein can also be applied to networks other than LTE, LTE-A, LTE-A Pro, or NR networks. For example, the described techniques can be applied to a variety of other wireless communication systems, such as Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM, and other systems and radio technologies not explicitly mentioned herein.

[0227] The information and signals described herein can be represented using any of a wide variety of different techniques and methods. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referred to throughout this description can be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, light fields or light particles, or any combination thereof.

[0228] The various illustrative boxes and components described herein can be implemented or executed using a general-purpose processor, DSP, ASIC, CPU, FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. The general-purpose processor may be a microprocessor, but in alternatives, the processor may be any processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors working in conjunction with a DSP core, or any other such configuration).

[0229] The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored or transmitted as one or more instructions or code on a computer-readable medium. Other examples and implementations fall within the scope of this disclosure and the appended claims. For example, due to the nature of software, the functions described herein may be implemented using software executed by a processor, hardware, firmware, hardwired, or any combination thereof. Features implementing the functions may also be physically located in various locations, including being distributed such that different parts of the function are implemented at different physical locations.

[0230] Computer-readable media includes both non-transient computer storage media and communication media, encompassing any medium that facilitates the transfer of a computer program from one location to another. Non-transient storage media can be any available medium accessible to a general-purpose or special-purpose computer. By way of example and not limitation, non-transient computer-readable media may include RAM, ROM, electrically erasable programmable ROM (EEPROM), flash memory, compact disc (CD) ROM or other optical disc storage, magnetic disk storage or other magnetic storage devices, or any other non-transient medium that can be used to carry or store desired program code in the form of instructions or data structures and is accessible to a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor. Similarly, any connection is also legitimately referred to as computer-readable media. For example, if software is transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then that coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of computer-readable media. As used in this article, disk and disc include CDs, laser discs, optical discs, DVDs, floppy disks, and Blu-ray discs, where disks often magnetically reproduce data while discs optically reproduce data using lasers. Combinations of these media are also included within the scope of computer-readable media.

[0231] As used herein (including in the claims), the word "or" in an enumeration of items (e.g., an enumeration of items accompanied by phrases such as "at least one of" or "one or more of") indicates an inclusive enumeration, such that an enumeration of at least one of, for example, A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C). Similarly, as used herein, the phrase "based on" should not be interpreted as referring to a closed set of conditions. For example, an example step described as "based on condition A" may be based on both condition A and condition B without departing from the scope of this disclosure. In other words, as used herein, the phrase "based on" should be interpreted in the same manner as the phrase "at least partially based on".

[0232] In the accompanying drawings, similar components or features may have the same reference numerals. Furthermore, components of the same type may be distinguished by a dash following the reference numeral and a second reference numeral used to differentiate between similar components. If only the first reference numeral is used in the description, the description may apply to any of the similar components having the same first reference numeral, regardless of the second reference numeral or other subsequent reference numerals.

[0233] The descriptions herein, illustrated with reference to the accompanying drawings, depict exemplary configurations and are not representative of all examples that may be implemented or fall within the scope of the claims. The term "example" as used herein means "serving as an example, instance, or illustration" and does not imply "superior" or "outperforming" other examples. This detailed description includes specific details to provide an understanding of the described techniques. However, these techniques may be practiced without these specific details. In some instances, known structures and devices are shown in block diagram form to avoid obscuring the concepts of the described examples.

[0234] The description provided herein is intended to enable those skilled in the art to make or use this disclosure. Various modifications to this disclosure will be apparent to those skilled in the art, and the universal principles defined herein can be applied to other variations without departing from the scope of this disclosure. Therefore, this disclosure is not limited to the examples and designs described herein, but should be granted the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for conducting wireless communication at a first user equipment (UE), comprising: Receive sidelink communication from the second UE via the sidelink channel; A feedback message is transmitted to the second UE via a sidelink feedback channel using a first resource configuration, wherein the first resource configuration indicates a first set of one or more sidelink feedback channel resources, the feedback message is at least partially based on the sidelink communication, and wherein the first set of one or more sidelink feedback channel resources is associated with a first set of sub-channels of a frequency band; as well as Inter-UE coordination is performed using a second resource configuration, wherein the second resource configuration indicates a second set of one or more sidelink feedback channel resources, the second set of one or more sidelink feedback channel resources being different from the first set of one or more sidelink feedback channel resources and associated with a second set of sub-channels of the frequency band, and wherein the feedback message uses the first set of one or more sidelink feedback channel resources and the second set of one or more sidelink feedback channel resources to coordinate signaling multiplexing with the UEs.

2. The method of claim 1, further comprising: Receive an instruction regarding the use of the second resource configuration to perform the inter-UE coordination.

3. The method of claim 1, further comprising: Receive the signal to configure the second resource configuration.

4. The method of claim 1, further comprising: The feedback message is transmitted separately from the UE via the sidelink feedback channel.

5. The method of claim 1, wherein performing the inter-UE coordination comprises: The coordination between the UEs is transmitted at least in part based on the contention-free channel access protocol.

6. The method of claim 1, wherein performing the inter-UE coordination comprises: Perform channel access procedures on the side link channel; as well as The inter-UE coordination is performed at least in part based on the results of the channel access procedure.

7. The method of claim 1, wherein performing the inter-UE coordination comprises: The monitoring indicates that the sidelink control information message coordinated between the UEs should be executed; as well as The coordination between UEs is performed at least in part based on the results of the monitoring.

8. The method of claim 1, wherein performing the inter-UE coordination comprises: Transmit a sidelink control information message instructing the first UE to perform inter-UE coordination. as well as The coordination between UEs is performed at least in part based on the side link control information messages.

9. The method of claim 1, wherein performing the inter-UE coordination comprises: Coordination between the UEs for transmitting, receiving, or simultaneously transmitting and receiving.

10. A method for conducting wireless communication at a first user equipment (UE), comprising: Transmitting sidelink communication to the second UE via the sidelink channel; Feedback messages are received from the second UE via a sidelink feedback channel using a first resource configuration, the first resource configuration indicating a first set of one or more sidelink feedback channel resources, the feedback messages being at least partially based on the sidelink communication, and wherein the first set of one or more sidelink feedback channel resources is associated with a first set of sub-channels of a frequency band; as well as Inter-UE coordination is performed using a second resource configuration, wherein the second resource configuration indicates a second set of one or more sidelink feedback channel resources, the second set of one or more sidelink feedback channel resources being different from the first set of one or more sidelink feedback channel resources and associated with a second set of sub-channels of the frequency band, and wherein the feedback message uses the first set of one or more sidelink feedback channel resources and the second set of one or more sidelink feedback channel resources to coordinate signaling multiplexing with the UEs.

11. The method of claim 10, further comprising: Transmit an instruction regarding the use of the second resource configuration to perform inter-UE coordination via the sidelink feedback channel.

12. The method of claim 10, further comprising: Transmit a signal configuring the second resource configuration.

13. The method of claim 10, further comprising: The feedback message is received separately from the UE via the sidelink feedback channel.

14. The method of claim 10, wherein performing the inter-UE coordination comprises: The coordination between the UEs is transmitted at least in part based on the contention-free channel access protocol.

15. The method of claim 10, wherein performing the inter-UE coordination comprises: Perform channel access procedures on the side link channel; as well as The inter-UE coordination is performed at least in part based on the results of the channel access procedure.

16. The method of claim 10, wherein performing the inter-UE coordination comprises: Transmit a sidelink control information message indicating that the inter-UE coordination should be performed; as well as The inter-UE coordination is performed at least in part based on the results of the sidelink control information messages.

17. The method of claim 10, wherein performing the inter-UE coordination comprises: Receive a sidelink control information message instructing the second UE to perform inter-UE coordination; as well as The coordination between UEs is performed at least in part based on the side link control information messages.

18. The method of claim 10, wherein performing the inter-UE coordination comprises: Coordination between the UEs for transmitting, receiving, or simultaneously transmitting and receiving.

19. An apparatus for performing wireless communication at a first user equipment (UE), comprising: One or more processors; One or more memories coupled to the one or more processors; as well as One or more processor-readable instructions stored in the one or more memories and executable individually or jointly by the one or more processors to cause the device to perform the following operations: Receive sidelink communication from the second UE via the sidelink channel; A feedback message is transmitted to the second UE via a sidelink feedback channel using a first resource configuration, wherein the first resource configuration indicates a first set of one or more sidelink feedback channel resources, the feedback message is at least partially based on the sidelink communication, and wherein the first set of one or more sidelink feedback channel resources is associated with a first set of sub-channels of a frequency band; as well as Inter-UE coordination is performed using a second resource configuration, wherein the second resource configuration indicates a second set of one or more sidelink feedback channel resources, the second set of one or more sidelink feedback channel resources being different from the first set of one or more sidelink feedback channel resources and associated with a second set of sub-channels of the frequency band, and wherein the feedback message uses the first set of one or more sidelink feedback channel resources and the second set of one or more sidelink feedback channel resources to coordinate signaling multiplexing with the UEs.

20. The apparatus of claim 19, wherein the one or more processor-readable instructions are further executable by the one or more processors to cause the apparatus to: Receive an instruction regarding the use of the second resource configuration to perform the inter-UE coordination.

21. The apparatus of claim 19, wherein the one or more processor-readable instructions are further executable by the one or more processors to cause the apparatus to: Receive the signal to configure the second resource configuration.

22. The apparatus of claim 19, wherein the one or more processor-readable instructions are further executable by the one or more processors to cause the apparatus to: The feedback message is transmitted separately and in coordination with the UE.

23. The apparatus of claim 19, wherein one or more processor-readable instructions for performing the inter-UE coordination are executable by the one or more processors to cause the apparatus to: The coordination between the UEs is transmitted at least in part based on the contention-free channel access protocol.

24. The apparatus of claim 19, wherein one or more processor-readable instructions for performing the inter-UE coordination are executable by the one or more processors to cause the apparatus to: Perform channel access procedures on the sidelink channel; and The inter-UE coordination is performed at least in part based on the results of the channel access procedure.

25. The apparatus of claim 19, wherein one or more processor-readable instructions for performing the inter-UE coordination are executable by the one or more processors to cause the apparatus to: The monitoring indicates the execution of the sidelink control information message for inter-UE coordination; and The coordination between UEs is performed at least in part based on the results of the monitoring.

26. The apparatus of claim 19, wherein one or more processor-readable instructions for performing the inter-UE coordination are executable by the one or more processors to cause the apparatus to: Transmit a sidelink control information message instructing the first UE to perform inter-UE coordination; and The coordination between UEs is performed at least in part based on the side link control information messages.

27. The apparatus of claim 19, wherein one or more processor-readable instructions for performing the inter-UE coordination are executable by the one or more processors to cause the apparatus to: Coordination between the UEs for transmitting, receiving, or simultaneously transmitting and receiving.

28. The apparatus of claim 19, wherein the one or more processor-readable instructions are further executable by the one or more processors to cause the apparatus to: Transmit sidelink control signaling.

29. An apparatus for performing wireless communication at a first user equipment (UE), comprising: One or more processors; One or more memories coupled to the one or more processors; as well as One or more processor-readable instructions stored in the one or more memories and executable individually or jointly by the one or more processors to cause the device to perform the following operations: Transmitting sidelink communication to the second UE via the sidelink channel; Feedback messages are received from the second UE via a sidelink feedback channel using a first resource configuration, the first resource configuration indicating a first set of one or more sidelink feedback channel resources, the feedback messages being at least partially based on the sidelink communication, and wherein the first set of one or more sidelink feedback channel resources is associated with a first set of sub-channels of a frequency band; as well as Inter-UE coordination is performed using a second resource configuration, wherein the second resource configuration indicates a second set of one or more sidelink feedback channel resources, the second set of one or more sidelink feedback channel resources being different from the first set of one or more sidelink feedback channel resources and associated with a second set of sub-channels of the frequency band, and wherein the feedback message uses the first set of one or more sidelink feedback channel resources and the second set of one or more sidelink feedback channel resources to coordinate signaling multiplexing with the UEs.

30. The apparatus of claim 29, wherein the one or more processor-readable instructions are further executable by the one or more processors to cause the apparatus to: Transmit an instruction regarding the use of the second resource configuration to perform inter-UE coordination via the sidelink feedback channel.

31. The apparatus of claim 29, wherein the one or more processor-readable instructions are further executable by the one or more processors to cause the apparatus to: Transmit a signal configuring the second resource configuration.

32. The apparatus of claim 29, wherein the one or more processor-readable instructions are further executable by the one or more processors to cause the apparatus to: The feedback message is received separately from the UE via the sidelink feedback channel.

33. The apparatus of claim 29, wherein one or more processor-readable instructions for performing the inter-UE coordination are executable by the one or more processors to cause the apparatus to: The coordination between the UEs is transmitted at least in part based on the contention-free channel access protocol.

34. The apparatus of claim 29, wherein one or more processor-readable instructions for performing the inter-UE coordination are executable by the one or more processors to cause the apparatus to: Perform channel access procedures on the sidelink channel; and The inter-UE coordination is performed at least in part based on the results of the channel access procedure.

35. The apparatus of claim 29, wherein one or more processor-readable instructions for performing the inter-UE coordination are executable by the one or more processors to cause the apparatus to: Transmit a sidelink control information message indicating that the inter-UE coordination will be performed; and The inter-UE coordination is performed at least in part based on the results of the sidelink control information messages.

36. The apparatus of claim 29, wherein one or more processor-readable instructions for performing the inter-UE coordination are executable by the one or more processors to cause the apparatus to: Receive a sidelink control information message instructing the second UE to perform inter-UE coordination; and The coordination between UEs is performed at least in part based on the side link control information messages.

37. The apparatus of claim 29, wherein one or more processor-readable instructions for performing the inter-UE coordination are executable by the one or more processors to cause the apparatus to: Coordination between the UEs for transmitting, receiving, or simultaneously transmitting and receiving.

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