Transmission of reverse link grants for anchor-based sidelink communications

Abstract

A wireless communication system and method related to the transmission of a reverse link grant for an anchor-based sidelink communication is provided. A first user equipment (UE) determines multiple reverse link grants for corresponding multiple UEs. The first UE sends a first sidelink control information (SCI) on a physical sidelink control channel (PSCCH). The first SCI may indicate whether user data follows in a physical sidelink shared channel (PSSCH). The first UE sends a demodulation reference signal (DMRS) and a second SCI on the PSSCH. The second SCI includes multiple reverse link grants in a block. The second SCI is rate matched from the start of the PSSCH instead of from the DMRS. Alternatively, a third SCI is introduced after the second SCI, wherein the second SCI starts from the DMRS, and the third SCI is rate matched from the start of the PSSCH and includes a block of reverse link grants.

Description

Technical Field

[0001] The present application relates to wireless communication systems, and more particularly, to sending a reverse link grant by an anchor user equipment (UE) to a client UE. Background Art

[0002] Wireless communication systems are widely deployed to provide various types of communication content, such as voice, video, packet data, messaging, broadcast, etc. These systems are capable of supporting communication with multiple users by sharing available system resources (e.g., time, frequency, and power). A wireless multiple-access communication system may include multiple base stations (BSs), each of which simultaneously supports communication for multiple communication devices, which may also be referred to as user equipment (UE).

[0003] In a wireless communication network, a BS can communicate with a UE in both the uplink direction and the downlink direction. Sidelinks were introduced to allow a UE to send data to another UE without tunneling through the BS and / or associated core network. Sidelink technology has been extended to provide device-to-device (D2D) communications, vehicle-to-everything (V2X) communications, and / or cellular vehicle-to-everything (C-V2X) communications. Similarly, NR can be extended to support sidelink communications for D2D, V2X, and / or C-V2X on dedicated spectrum, licensed spectrum, and / or unlicensed spectrum.

[0004] In a scenario where one UE acts as an anchor UE for other UEs participating in sidelink communications, the anchor UE may assume the scheduling role for the other UEs participating in sidelink communications. However, problems may arise when the anchor UE attempts to provide reverse link grants to multiple UEs, which may waste payload resources and / or find only limited use (which is missing some scenarios (such as when there is no forward link data for transmission)). Therefore, there is a need to provide techniques for transmitting reverse link grants to multiple UEs in a more efficient manner. Summary of the invention

[0005] Some aspects of the present disclosure are summarized below to provide a basic understanding of the technology discussed. This overview is not an exhaustive review of all expected features of the present disclosure, and is neither intended to identify key or important elements of all aspects of the present disclosure, nor is it intended to describe the scope of any or all aspects of the present disclosure. Its sole purpose is to provide some concepts of one or more aspects of the present disclosure in an overview form as a prelude to a more detailed description given later.

[0006] For example, in one aspect of the present disclosure, a method of wireless communication includes: determining, by a first user equipment (UE), a plurality of reverse link grants for corresponding multiple UEs to send sidelink data to the first UE. The method also includes: sending, by the first UE, first sidelink control information on a physical sidelink control channel (PSCCH). The method also includes: sending, by the first UE, a demodulation reference signal (DMRS) and second sidelink control information on a physical sidelink shared channel (PSSCH), the second sidelink control information including the plurality of reverse link grants in a block.

[0007] In an additional aspect of the present disclosure, a method of wireless communication includes: determining, by a first user equipment (UE), a plurality of reverse link grants for a plurality of UEs to send sidelink data to the first UE. The method also includes: sending, by the first UE, first sidelink control information on a physical sidelink control channel (PSCCH). The method also includes: sending, by the first UE, on a PSSCH, the following: a demodulation reference signal (DMRS); second sidelink control information configured to provide information related to third sidelink control information; and the third sidelink control information including the plurality of reverse link grants in a block.

[0008] In an additional aspect of the present disclosure, a user equipment (UE) includes: a processor configured to: determine a plurality of reverse link grants for a corresponding plurality of UEs to send sidelink data to the user equipment. The user equipment also includes: a transceiver configured to: send first sidelink control information on a physical sidelink control channel (PSCCH). The transceiver is further configured to: send a demodulation reference signal (DMRS) and second sidelink control information on a physical sidelink shared channel (PSSCH), the second sidelink control information including the plurality of reverse link grants in a block.

[0009] In an additional aspect of the present disclosure, a user equipment (UE) includes: a processor configured to: determine a plurality of reverse link grants for a plurality of UEs to send sidelink data to the user equipment. The user equipment also includes: a transceiver configured to: send first sidelink control information on a physical sidelink control channel (PSCCH). The transceiver is further configured to: send the following on a physical sidelink shared channel (PSSCH): a demodulation reference signal (DMRS); second sidelink control information configured to provide information related to third sidelink control information; and the third sidelink control information including the plurality of reverse link grants in a block.

[0010] In an additional aspect of the present disclosure, a non-transitory computer-readable medium having program code recorded thereon is provided. The program code includes: code for causing a first user equipment (UE) to determine a plurality of reverse link grants for a corresponding plurality of UEs to send sidelink data to the first UE. The program code also includes: code for causing the first UE to send a first sidelink control information on a physical sidelink control channel (PSCCH). The program code also includes: code for causing the first UE to send a demodulation reference signal (DMRS) and a second sidelink control information on a physical sidelink shared channel (PSSCH), the second sidelink control information including the plurality of reverse link grants in a block.

[0011] In an additional aspect of the present disclosure, a non-transitory computer-readable medium having program code recorded thereon is provided. The program code includes: code for causing a first user equipment (UE) to determine multiple reverse link grants for multiple UEs to send sidelink data to the first UE. The program code includes: code for causing the first UE to send first sidelink control information on a physical sidelink control channel (PSCCH). The program code includes: code for causing the first UE to send the following on a physical sidelink shared channel (PSSCH): a demodulation reference signal (DMRS); second sidelink control information, which is configured to provide information related to third sidelink control information; and the third sidelink control information, which includes the multiple reverse link grants in a block.

[0012] In an additional aspect of the present disclosure, a user equipment includes: a unit for determining a plurality of reverse link grants for a corresponding plurality of UEs to send sidelink data to the user equipment. The user equipment also includes: a unit for sending a first sidelink control information on a physical sidelink control channel (PSCCH). The user equipment also includes: a unit for sending a demodulation reference signal (DMRS) and a second sidelink control information on a physical sidelink shared channel (PSSCH), the second sidelink control information including the plurality of reverse link grants in a block.

[0013] In an additional aspect of the present disclosure, a user equipment (UE) includes: a unit for determining a plurality of reverse link grants for a plurality of UEs to send sidelink data to the user equipment. The user equipment also includes: a unit for sending a first sidelink control information on a physical sidelink control channel (PSCCH). The user equipment also includes: a unit for sending the following on a physical sidelink shared channel (PSSCH): a demodulation reference signal (DMRS); second sidelink control information configured to provide information related to third sidelink control information; and the third sidelink control information including the plurality of reverse link grants in a block.

[0014] After reviewing the following description of specific, exemplary embodiments of the present invention in conjunction with the accompanying drawings, other aspects, features, and embodiments of the present invention will become apparent to those of ordinary skill in the art. Although features of the present invention may be discussed below with respect to certain embodiments and drawings, all embodiments of the present invention may include one or more of the advantageous features discussed herein. In other words, although one or more embodiments may be discussed as having certain advantageous features, one or more of these features may also be used in accordance with the various embodiments of the present invention discussed herein. In a similar manner, although exemplary embodiments may be discussed below as device, system, or method embodiments, it should be understood that these exemplary embodiments may be implemented in a variety of devices, systems, and methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A wireless communication network in accordance with some aspects of the present disclosure is shown.

[0016] Figure 2

[0013] A wireless communication network providing sidelink communications in accordance with some aspects of the present disclosure is shown.

[0017] Figure 3 A sidelink communication scheme according to some aspects of the present disclosure is shown.

[0018] Figure 4 is a simplified block diagram of an exemplary time slot according to some aspects of the present disclosure.

[0019] Figure 5 is a block diagram of an exemplary client user equipment (UE) according to some aspects of the present disclosure.

[0020] Figure 6 is a block diagram of an exemplary anchor UE according to some aspects of the present disclosure.

[0021] Figure 7is a flow chart of a first reverse link grant transmission process according to some aspects of the present disclosure.

[0022] Figure 8 is a block diagram of sidelink resources with reverse link grants in accordance with some aspects of the present disclosure.

[0023] Fig. 9 is a flow chart of a process for sending second stage control information according to a rate matching rule according to some aspects of the present disclosure.

[0024] Fig.10 is a block diagram of sidelink resources with reverse link grants in accordance with some aspects of the present disclosure.

[0025] Fig.11 is a flow chart of a second reverse link grant transmission process according to some aspects of the present disclosure.

[0026] Fig.12 is a block diagram of sidelink resources with reverse link grants in accordance with some aspects of the present disclosure.

[0027] Fig.13 is a flow chart of a third reverse link grant transmission process according to some aspects of the present disclosure.

[0028] Fig.14 is a block diagram of sidelink resources with reverse link grants in accordance with some aspects of the present disclosure.

[0029] Fig.15 is a block diagram of sidelink resources with reverse link grants in accordance with some aspects of the present disclosure. DETAILED DESCRIPTION

[0030] The detailed description set forth below in conjunction with the accompanying drawings is intended as a description of various configurations, rather than being intended to represent the only configuration in which the concepts described herein may be practiced. In order to provide a comprehensive understanding of the various concepts, the detailed description includes specific details. However, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details. In some instances, in order to avoid obscuring these concepts, known structures and components are shown in block diagram form.

[0031] In general, the present disclosure relates to wireless communication systems (also referred to as wireless communication networks). In various embodiments, the techniques and apparatus may be used for wireless communication networks such as code division multiple access (CDMA) networks, time division multiple access (TDMA) networks, frequency division multiple access (FDMA) networks, orthogonal FDMA (OFDMA) networks, single carrier FDMA (SC-FDMA) networks, LTE networks, global system for mobile communications (GSM) networks, fifth generation (5G) or new radio (NR) networks, and other communication networks. As described herein, the terms "network" and "system" may be used interchangeably.

[0032] OFDMA network can realize radio technology such as Evolved UTRA (E-UTRA), Institute of Electrical and Electronics Engineers (IEEE) 802.11, IEEE 802.16, IEEE 802.20, Flash-OFDM, etc. UTRA, E-UTRA and GSM are part of Universal Mobile Telecommunications System (UMTS). Specifically, Long Term Evolution (LTE) is a version of UMTS using E-UTRA. UTRA, E-UTRA, GSM, UMTS and LTE are described in documents provided by an organization named "3rd Generation Partnership Project" (3GPP), and cdma2000 is described in documents from an organization named "3rd Generation Partnership Project 2" (3GPP2). These various radio technologies and standards are known or are being developed. For example, the 3rd Generation Partnership Project (3GPP) is a collaboration between various telecommunications association groups to define a globally applicable third generation (3G) mobile phone specification. 3GPP Long Term Evolution (LTE) is a 3GPP plan to improve the UMTS mobile phone standard. 3GPP may define specifications for next generation mobile networks, mobile systems, and mobile devices. The present disclosure relates to the evolution of wireless technologies from LTE, 4G, 5G, NR and beyond with shared access to wireless spectrum using a collection of new and different radio access technologies or radio air interfaces between networks.

[0033] 5G networks are expected to enable diverse deployments, diverse spectrum, and diverse services and devices using a unified OFDM-based air interface. To achieve these goals, in addition to developing new radio technologies for 5G NR networks, further enhancements to LTE and LTE-A are also being considered. 5G NR will be able to scale to provide the following coverage: (1) Coverage for the massive Internet of Things (IoT), which has ultra-high density (e.g., ~1M nodes / km) 2(1) coverage with ultra-low complexity (e.g., ~10s of bits / second), ultra-low energy (e.g., ~10+ years of battery life), and deep coverage with the ability to reach challenging locations; (2) coverage including mission-critical control with strong security for protecting sensitive personal, financial, or confidential information, ultra-high reliability (e.g., ~99.9999% reliability), ultra-low latency (e.g., ~1ms), and coverage for users with a wide range of mobility or lack of mobility; and (3) coverage with enhanced mobile broadband, including extremely high capacity (e.g., ~10Tbps / km 2 ), extreme data rates (e.g., multi-Gbps rates, 100+Mbps user experience rates), and deep perception with improved discovery and optimization.

[0034] 5G NR can be implemented using an optimized OFDM-based waveform with a scalable digital scheme and transmission time interval (TTI); a common flexible framework to efficiently multiplex services and features using dynamic, low-latency time division duplex (TDD) design / frequency division duplex (FDD) design; and advanced wireless technologies such as massive multiple-input multiple-output (MIMO), robust millimeter wave (mmWave) transmission, advanced channel coding, and device-centric mobility. The scalability of the digital scheme in 5G NR (with scaling of subcarrier spacing) can efficiently address the operation of diverse services across diverse spectrums and diverse deployments. For example, in various outdoor and macro coverage deployments of less than 3GHz FDD / TDD implementations, the subcarrier spacing can appear at 15kHz on bandwidths such as 5, 10, 20MHz, etc. For other various outdoor and small cell coverage deployments of TDD greater than 3GHz, the subcarrier spacing can appear at 30kHz on 80 / 100MHz BW. For various other indoor broadband implementations, using TDD on the unlicensed portion of the 5 GHz band, subcarrier spacing may occur at 60 kHz over 160 MHz BW. Finally, for various deployments transmitting with the mmWave component at 28 GHz with TDD, subcarrier spacing may occur at 120 kHz over 500 MHz BW.

[0035] 5G NR's scalable digital scheme facilitates scalable TTIs for different latency and quality of service (QoS) requirements. For example, shorter TTIs can be used for low latency and high reliability, while longer TTIs can be used for higher spectral efficiency. Efficient multiplexing of long and short TTIs allows transmissions to start on symbol boundaries. 5G NR also anticipates a self-contained integrated subframe design with UL / downlink scheduling information, data, and acknowledgments in the same subframe. The self-contained integrated subframe supports communications in unlicensed or contention-based shared spectrum, adaptive UL / downlink (which can be flexibly configured on a per-cell basis to dynamically switch between UL and downlink to meet current business needs).

[0036] The following further describes various other aspects and features of the present disclosure. It should be apparent that the teachings herein can be embodied in a variety of forms, and any specific structure, function, or both disclosed herein are representative rather than limiting. Based on the teachings herein, it should be understood by those of ordinary skill in the art that the aspects disclosed herein can be implemented independently of any other aspects, and two or more of these aspects can be combined in various ways. For example, using any number of aspects set forth herein, a device can be implemented or a method can be implemented. In addition, using other structures, functions, or structures and functions other than or different from one or more aspects of the aspects set forth herein, such a device can be implemented, or such a method can be implemented. For example, a method can be implemented as a part of a system, device, device, and / or as an instruction stored on a computer-readable medium for execution on a processor or computer. In addition, an aspect can include at least one element of a claim.

[0037] Sidelink communication refers to communication between user equipment devices (UE) without tunneling through a base station (BS) and / or a core network (e.g., alternatively via a PC5 link interface). Sidelink communication can be transmitted on a physical sidelink control channel (PSCCH) and a physical sidelink shared channel (PSSCH). PSCCH is similar to a physical downlink control channel (PDCCH) in a downlink (DL) communication between a BS and a UE, while PSSCH is similar to a physical downlink shared channel (PDSCH). For example, PSCCH can carry sidelink control information (SCI), while PSSCH can carry sidelink data. Each PSCCH is associated with a corresponding PSSCH, wherein the SCI in the PSCCH can carry scheduling information for sidelink data transmission in the associated PSSCH. In some examples, a UE can send an SCI carrying a PSSCH, which can be indicated in multiple stages (e.g., two stages, three stages, etc.).

[0038] In the first stage control (also referred to herein as SCI-1), the UE may send a PSCCH carrying information for resource allocation and decoding of the second stage control. The first stage SCI may include at least one of the following: priority, PSSCH resource assignment, resource reservation period (if enabled), PSSCH DMRS mode (if more than one mode is configured), second stage SCI format (e.g., the size of the second SCI), the amount of resources used for the second stage SCI, the number of PSSCH demodulation reference signal (DMRS) ports, modulation and coding scheme (MCS), etc. In the second stage control (also referred to herein as SCI-2), the UE may send information for decoding user data on the PSSCH. SCI-2 may include a 16-bit L1 destination identifier (ID), an 8-bit L1 source ID, a HARQ process ID, a new data indicator (NDI), a redundancy version (RV), etc. Sidelink communications may also be transmitted on a physical sidelink feedback control channel (PSFCH), which indicates an acknowledgment (ACK)-negative acknowledgment (NACK) for a previously transmitted PSSCH. Use cases for sidelink communications may include vehicle-to-everything (V2X), Industrial Internet of Things (IIoT), and / or NR lite, to name a few.

[0039] As used herein, the term "sidelink UE" may refer to a user equipment device that performs device-to-device communication or other types of communication with another user equipment device, independent of any tunnel transmission through a BS (e.g., gNB) and / or an associated core network. As used herein, the terms "sidelink sending UE" and "transmitting UE" may refer to a user equipment device that performs a sidelink sending operation. As used herein, the terms "sidelink receiving UE" and "receiving UE" may refer to a user equipment device that performs a sidelink receiving operation. As used herein, the terms "anchor UE" or "sidelink anchor UE" may refer to a sidelink UE designated as an anchor node using an independent sidelink configuration, which can autonomously initiate sidelink operations (e.g., independent of any cell and / or associated core network), and these terms are interchangeable without departing from the scope of the present disclosure.

[0040] NR supports multiple modes of radio resource allocation (RRA) for sidelinks on licensed spectrum, including mode-1 RRA and mode-2 RRA. Mode-1 RRA supports network-controlled RRA that can be used for coverage-inside sidelink communications. For example, a serving BS (e.g., a gNB) can determine radio resources on behalf of a sidelink UE and send an indication of the radio resources to the sidelink UE. In some aspects, the serving BS uses downlink control information (DCI) to authorize sidelink transmissions. However, for this mode, there is significant base station participation, and it is usually operable when the sidelink UE is within the coverage area of ​​the serving BS, but it is not necessarily operable for coverage-outside sidelink scenarios. Mode-2 RRA supports autonomous RRA that can be used for coverage-outside sidelink UEs or partially covered sidelink UEs. For example, a coverage-outside sidelink UE or partially covered UE can be pre-configured with a sidelink resource pool, and radio resources for sidelink communications can be selected from the pre-configured sidelink resource pool. For this mode, it is possible for the V2X system to operate independently of the serving BS. However, Mode-2 RRA relies on sidelink setups across different environments (e.g., vehicles). For example, this mode may require that the sidelink setup is unified so that each sidelink UE (e.g., vehicle) can communicate with each other. This will rely on user equipment vendors (e.g., different car manufacturers) to coordinate and implement common sidelink setups. This may place a large burden on user equipment vendors to develop and implement unified sidelink setups so that NR-U sidelink user equipment devices can communicate via corresponding sidelink connections. Therefore, it is expected that the NR-U sidelink system will be deployed as a standalone system.

[0041] An independent system may include a sidelink UE designated as an anchor UE (e.g., an anchor node). The anchor UE may autonomously (e.g., independently of any cell and / or associated core network) initiate sidelink operations with one or more client UEs. Accordingly, the anchor UE may announce system parameters for operation of each of the client UEs (e.g., information associated with a sidelink master information block (SL-MIB), remaining minimum system information (RMSI), a primary synchronization signal (PSS), a secondary synchronization signal (SSS), etc.), and the anchor UE may provide corresponding radio resource control (RRC) configurations for the corresponding client UEs. For example, the anchor UE may provide a first RRC configuration to a first client UE, and a different second RRC configuration to a second client UE. In addition, although the anchor UE may interface with the client UE using mode-1 RRA or mode-2 RRA, the signaling received by the client UE may remain the same between the two modes.

[0042] In NR Vehicle-to-Everything (V2X), a client UE (e.g., a transmitting UE) may initiate SCI and sidelink data transmission to an anchor UE (e.g., a receiving UE). The client UE may select resources for sidelink transmission based on channel sensing and channel measurements. The sensing and channel measurements performed by the client UE may present the channel conditions and / or interference at the client UE, but may not necessarily represent the channel conditions and / or interference experienced by the anchor UE when the data is being received and decoded. Accordingly, the resources selected by the client UE may not be the resources most suitable for the anchor UE. In contrast, in an anchor-client architecture, it may be preferable to allow the anchor UE to schedule transmissions from the client UE to the anchor UE for better efficiency - such a connection from the client UE to the anchor UE may be referred to as a reverse link in this article (e.g., where the link from the anchor UE to the client UE is referred to as a forward link in this article).

[0043] The present application describes a mechanism for sending one or more reverse link grants from an anchor UE to facilitate sidelink communications between the anchor UE and one or more client UEs. Each reverse link grant may specify scheduling information, such as information indicating sidelink resources (e.g., time-frequency resources) and / or transmission parameters (e.g., modulation and coding scheme (MCS) and / or demodulation reference signal (DMRS) pattern) for sidelink transmissions from the corresponding client UE to the anchor UE. Accordingly, the anchor UE may initiate sidelink communications by sending scheduling information for sidelink transmissions to the client UE. After receiving the scheduling information included in the reverse link grant, the client UE may send sidelink data to the anchor UE based on the received reverse link grant. As the number of client UEs associated with the anchor UE and / or the number of reverse link grants that the anchor UE is configured to send increases, the resources available for user data transmission on the PSSCH decrease.

[0044] Accordingly, in some embodiments, the anchor UE may send a reverse link grant in the form of a shared SCI communication. More specifically, the anchor UE may aggregate one or more reverse link grants into a block and send the block in SCI-2 or in the third stage control information (also referred to herein as SCI-3) on the PSSCH. In some cases, the anchor UE may also send information about the block in a previous stage of the control information, such as the existence of the block, the size of the block, the number of reverse link grants included in the block, etc. For example, in the case where SCI-2 contains a block, the anchor UE may include information about the block in SCI-1, and in the case where SCI-3 contains a block, SCI-2 may include information about the block. To this end, sending a block of reverse link grants may involve adding data fields to SCI-1 and / or SCI-2 and / or modifying existing data fields of SCI-1 and / or SCI-2.

[0045] In addition, the anchor UE may rate match the SCI (e.g., SCI-2 or SCI-3) containing the reverse link grant according to a modified rate matching rule (e.g., where the demodulation reference signal does not start at the beginning of the PSSCH). Rate matching the SCI according to the rate matching rule may involve rate matching starting from a specific position on the PSSCH so that the SCI occupies a certain set of resource elements on the PSSCH after the position. For example, in the absence of user data to be sent to one or more client UEs on the forward link, the anchor UE may rate match the SCI (e.g., SCI-2 or SCI-3) from the beginning of the PSSCH in the case where the DMRS starts later. In this way, the first symbol in the time slot is not wasted (i.e., empty). In another example, in the case where the DMRS starts later, the anchor UE may rate match the SCI (e.g., SCI-2 or SCI-3) from the DMRS, and rate match back to the beginning of the PSSCH (e.g., before the DMRS starts) so that those previous symbols that would otherwise be left empty are still used. Further, the reverse link grant may be sent together with the user data or independently of the user data. To this end, rate matching the SCI according to the rate matching rule may involve accommodating the transmission of the user data on the PSSCH. This may include adding information to the header data of the SCI-1 and / or SCI-2 to allow the receiving client UE to identify how many reverse link grants are included in a given SCI block, and the UE ID corresponding to the corresponding reverse link grant in the given block.

[0046] Aspects of the present disclosure provide several benefits. For example, by aggregating multiple reverse link grants into a single block, the resources (e.g., time-frequency resources) involved in sending reverse link grants can be reduced. In addition, by sending a block of reverse link grants in the form of SCI on PSSCH, the block can be flexibly sent together with user data (such as forward link data) or independently of user data. To this end, in some cases, the anchor UE can send a reverse link grant to the client UE without having to wait for the forward link communication to the client UE, thereby improving turnaround time and / or throughput. In other cases, the anchor UE can send a block of reverse link grants while still accommodating user data (such as forward link data) in the same transmission. In such a case, the anchor UE can efficiently send a block of user data and reverse link grants.

[0047] Figure 1A wireless communication network 100 according to some aspects of the present disclosure is shown. The network 100 may be a 5G network. The network 100 includes a plurality of base stations (BSs) 105 (labeled 105a, 105b, 105c, 105d, 105e, and 105f, respectively) and other network entities. The BS 105 may be a station that communicates with the UE 115, and may also be referred to as an evolved Node B (eNB), a next generation eNB (gNB), an access point, and the like. Each BS 105 may provide communication coverage for a particular geographic area. In 3GPP, the term "cell" may refer to the particular geographic coverage area of ​​the BS 105 and / or the BS subsystem serving the coverage area, depending on the context in which the term is used.

[0048] The BS 105 may provide communication coverage for macro cells or small cells (e.g., pico cells or femto cells) and / or other types of cells. A macro cell typically covers a relatively large geographic area (e.g., a radius of several kilometers) and may allow unrestricted access by UEs with service subscriptions with a network provider. Small cells (such as pico cells) will typically cover a relatively small geographic area and may allow unrestricted access by UEs with service subscriptions with a network provider. Small cells (such as femto cells) will also typically cover a relatively small geographic area (e.g., a residence) and, in addition to unrestricted access, may also provide restricted access by UEs associated with the femto cell (e.g., UEs in a closed subscriber group (CSG), UEs for users in a residence, etc.). A BS for a macro cell may be referred to as a macro BS. A BS for a small cell may be referred to as a small cell BS, a pico BS, a femto BS, or a home BS. In Figure 1 In the example shown in , BS 105d and 105e may be conventional macro BSs, while BS 105a-105c may be macro BSs implemented using one of three-dimensional (3D), full-dimensional (FD), or massive MIMO. BS 105a-105c may utilize their higher-dimensional MIMO capabilities to utilize 3D beamforming in both elevation and azimuth beamforming to increase coverage and capacity. BS 105f may be a small cell BS, which may be a home node or a portable access point. BS 105 may support one or more (e.g., two, three, four, etc.) cells.

[0049] The network 100 may support synchronous operation or asynchronous operation. For synchronous operation, the BSs may have similar frame timing, and transmissions from different BSs may be approximately aligned in time. For asynchronous operation, the BSs may have different frame timing, and transmissions from different BSs may not be aligned in time.

[0050] UE 115 is dispersed throughout the wireless network 100, and each UE 115 can be stationary or mobile. UE 115 can also be referred to as a terminal, a mobile station, a subscriber unit, a station, etc. UE 115 can be a cellular phone, a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a tablet computer, a laptop computer, a cordless phone, a wireless local loop (WLL) station, etc. In one aspect, UE 115 can be a device including a universal integrated circuit card (UICC). In another aspect, UE can be a device that does not include UICC. In some aspects, UE 115 that does not include UICC can also be referred to as IoT device or Internet of Everything (IoE) device. UE 115a-115d is an example of a mobile smart phone type device that accesses the network 100. UE 115 can also be a machine that is specially configured for connected communications (including machine type communications (MTC), enhanced MTC (eMTC), narrowband IoT (NB-IoT), etc.). UE 115e-115h are examples of various machines configured for communication that access the network 100. UE 115i-115k are examples of vehicles equipped with wireless communication devices configured for communication that access the network 100. UE 115 may be able to communicate with any type of BS, whether macro BS, small cell, etc. Figure 1 In the present disclosure, lightning (e.g., communication link) indicates wireless transmission between UE 115 and serving BS 105 (which is a BS designated to serve UE 115 on downlink (DL) and / or uplink (UL)), desired transmission between BS 105, backhaul transmission between BSs, or sidelink transmission between UE 115 (such as and including embodiments according to the present disclosure).

[0051] In operation, BS 105a-105c can use 3D beamforming and cooperative spatial technology (e.g., coordinated multi-point (CoMP) or multiple connections) to serve UE 115a and 115b. Macro BS 105d can perform backhaul communication with BS 105a-105c and small cell BS 105f. Macro BS 105d also sends multicast services that are subscribed to and received by UE 115c and 115d. Such multicast services may include mobile TV or streaming video, or may include other services for providing community information, such as weather emergencies or alerts (e.g., Amber alerts or gray alerts).

[0052] The BS 105 may also communicate with a core network. The core network may provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. At least some of the BSs 105 (e.g., which may be examples of gNBs or access node controllers (ANCs)) may interface with the core network via a backhaul link (e.g., NG-C, NG-U, etc.) and may perform radio configuration and scheduling for communications with the UE 115. In various examples, the BSs 105 may communicate with each other directly or indirectly (e.g., through the core network) over a backhaul link (e.g., X1, X2, etc.), which may be a wired or wireless communication link.

[0053] The network 100 may also support mission-critical communications with ultra-reliable and redundant links for mission-critical devices, such as UE 115e, which may be a drone. The redundant communication links with UE 115e may include links from macro BSs 105d and 105e and links from small cell BS 105f. Other machine-type devices, such as UE 115f (e.g., a thermometer), UE 115g (e.g., a smart meter), and UE 115h (e.g., a wearable device), may communicate directly with a BS, such as small cell BS 105f and macro BS 105e, through the network 100, or by communicating with another user device that relays its information to the network, such as UE 115f transmitting temperature measurement information to a smart meter (UE 115g), which is then reported to the network through small cell BS 105f, in a multi-step configuration. The network 100 may also provide additional network efficiency through dynamic, low-latency TDD / FDD communications, such as V2V, V2X, C-V2X communications between UE 115i, 115j, or 115k and other UEs 115 and / or vehicle-to-infrastructure (V2I) communications between UE 115i, 115j, or 115k and BS 105.

[0054] In some implementations, the network 100 communicates using an OFDM-based waveform. An OFDM-based system may divide the system BW into multiple (K) orthogonal subcarriers, which are also commonly referred to as subcarriers, tones, frequency bands, etc. Each subcarrier may be modulated with data. In some cases, the subcarrier spacing between adjacent subcarriers may be fixed, and the total number of subcarriers (K) may depend on the system BW. The system BW may also be divided into subbands. In other cases, the subcarrier spacing and / or the duration of the TTI may be scalable.

[0055] In some aspects, BS 105 may assign or schedule transmission resources (e.g., in the form of time-frequency resource elements (REs)) for downlink (DL) and uplink (UL) transmissions in network 100. DL refers to the transmission direction from BS 105 to UE 115, while UL refers to the transmission direction from UE 115 to BS 105. Communications may be in the form of radio frames. Radio frames may be divided into a plurality of subframes or time slots, e.g., about 10. Each time slot may be further divided into micro-time slots. In FDD mode, simultaneous UL and DL transmissions may occur in different frequency bands. For example, each subframe includes a UL subframe in a UL frequency band and a DL subframe in a DL frequency band. In TDD mode, UL and DL transmissions occur at different time periods using the same frequency band. For example, a subset of subframes in a radio frame (e.g., a DL subframe) may be used for DL ​​transmission, and another subset of subframes in a radio frame (e.g., a UL subframe) may be used for UL transmission.

[0056] DL subframes and UL subframes may be further divided into several regions. For example, each DL or UL subframe may have a predefined region for the transmission of reference signals, control information, and data. A reference signal is a predetermined signal that facilitates communication between BS 105 and UE 115. For example, a reference signal may have a specific pilot pattern or structure, wherein a pilot tone may span the entire operational BW or frequency band, and each pilot tone may be located at a predefined time and a predefined frequency. For example, BS 105 may send a cell-specific reference signal (CRS) and / or a channel state information-reference signal (CSI-RS) to enable UE 115 to estimate a DL channel. Similarly, UE 115 may send a sounding reference signal (SRS) to enable BS 105 to estimate an UL channel. Control information may include resource assignments and protocol control. Data may include protocol data and / or operational data. In some aspects, BS 105 and UE 115 may communicate using a self-contained subframe. A self-contained subframe may include a portion for DL ​​communication and a portion for UL communication. A self-contained subframe may be DL-centric or UL-centric. A DL-centric subframe may include a longer duration for DL ​​communications (compared to UL communications). A UL-centric subframe may include a longer duration for UL communications (compared to UL communications).

[0057] In some aspects, the network 100 may be an NR network deployed on a licensed spectrum. The BS 105 may send synchronization signals (e.g., including PSS and SSS) in the network 100 to facilitate synchronization. The BS 105 may broadcast system information associated with the network 100 (e.g., including a master information block (MIB), remaining minimum system information (e.g., RMSI), and other system information (OSI)) to facilitate initial network access. In some cases, the BS 105 may broadcast the PSS, SSS, and / or MIB in the form of a synchronization signal block (SSB) on a physical broadcast channel (PBCH), and may broadcast the RMSI and / or OSI on a physical downlink shared channel (e.g., PDSCH).

[0058] In some aspects, a UE 115 attempting to access the network 100 may perform an initial cell search by detecting a PSS from the BS 105. The PSS may enable synchronization of period timing and may indicate a physical layer identification value. Subsequently, the UE 115 may receive the SSS. The SSS may enable radio frame synchronization and may provide a cell identification value, which may be combined with the physical layer identification value to identify a cell. The PSS and SSS may be located in the center portion of a carrier or in any suitable frequency within a carrier.

[0059] After receiving the PSS and SSS, the UE 115 may receive the MIB. The MIB may include system information for initial network access and scheduling information for RMSI and / or OSI. After decoding the MIB, the UE 115 may receive the RMSI and / or OSI. The RMSI and / or OSI may include radio resource control (RRC) information related to random access channel (RACH) procedures, paging, control resource set (CORESET) for physical downlink control channel (PDCCH) monitoring, physical UL control channel (PUCCH), physical UL shared channel (PUSCH), power control, and SRS.

[0060] After obtaining the MIB, RMSI and / or OSI, the UE 115 may perform a random access procedure to establish a connection with the BS 105. In some examples, the random access procedure may be a four-step random access procedure. For example, the UE 115 may send a random access preamble, and the BS 105 may respond with a random access response. The random access response (RAR) may include a detected random access preamble identifier (ID) corresponding to the random access preamble, timing advance (TA) information, UL authorization, a temporary cell radio network temporary identifier (C-RNTI), and / or a fallback indicator. Upon receiving the random access response, the UE 115 may send a connection request to the BS 105, and the BS 105 may respond with a connection response. The connection response may indicate contention resolution. In some examples, the random access preamble, RAR, connection request, and connection response may be referred to as message 1 (MSG1), message 2 (MSG2), message 3 (MSG3), and message 4 (MSG4), respectively. In some examples, the random access procedure may be a two-step random access procedure, where the UE 115 may send a random access preamble and a connection request in a single transmission, and the BS 105 may respond by sending a random access response and a connection response in a single transmission.

[0061] After establishing the connection, the UE 115 and the BS 105 may enter a normal operation phase, in which operation data may be exchanged. For example, the BS 105 may schedule the UE 115 for UL and / or DL ​​communications. The BS 105 may send an UL and / or DL ​​scheduling grant to the UE 115 via the PDCCH. The scheduling grant may be sent in the form of DL control information (DCI). The BS 105 may send a DL communication signal (e.g., carrying data) to the UE 115 via the PDSCH according to the DL scheduling grant. The UE 115 may send an UL communication signal to the BS 105 via the PUSCH and / or PUCCH according to the UL scheduling grant.

[0062] In some aspects, BS 105 may communicate with UE 115 using HARQ technology to improve communication reliability, for example, to provide URLLC services. BS 105 may schedule UE 115 to perform PDSCH communication by sending DL grants in PDCCH. BS 105 may send DL data packets to UE 115 in PDSCH according to the schedule. DL data packets may be sent in the form of transport blocks (TBs). If UE 115 successfully receives the DL data packet, UE 115 may send HARQ ACK to BS 105. On the contrary, if UE 115 fails to successfully receive the DL transmission, UE 115 may send HARQ NACK to BS 105. After receiving HARQ NACK from UE 115, BS 105 may retransmit the DL data packet to UE 115. The retransmission may include the same coded version of the DL data as the initial transmission. Alternatively, the retransmission may include a decoded version of the DL data different from the initial transmission. The UE 115 may apply soft combining to combine the coded data received from the initial transmission and the retransmission for decoding.The BS 105 and the UE 115 may also apply HARQ to UL communications using a substantially similar mechanism as DL HARQ.

[0063] In some aspects, the network 100 may operate on a system BW or a component carrier (CC) BW. The network 100 may divide the system BW into multiple BWPs (e.g., parts). The BS 105 may dynamically assign the UE 115 to operate on a specific BWP (e.g., a specific part of the system BW). The assigned BWP may be referred to as an active BWP. The UE 115 may monitor the active BWP for signaling information from the BS 105. The BS 105 may schedule the UE 115 to perform UL or DL ​​communications in the active BWP. In some aspects, the BS 105 may assign a pair of BWPs within the CC to the UE 115 for UL and DL communications. For example, the BWP pair may include a BWP for UL communication and a BWP for DL ​​communication.

[0064] In some aspects, network 100 may operate on a shared channel, which may include a shared frequency band and / or an unlicensed frequency band. For example, network 100 may be an NR-U network operating on an unlicensed frequency band. In such aspects, BS 105 and UE 115 may be operated by multiple network operating entities. In order to avoid conflicts, BS 105 and UE 115 may use a listen-before-talk (LBT) process to monitor transmission opportunities (TXOPs) in a shared channel. TXOP may also be referred to as COT (e.g., channel occupancy time). For example, a transmitting node (e.g., BS 105 or UE 115) may perform LBT before transmitting in a channel. When LBT passes, the transmitting node may continue to transmit. When LBT fails, the transmitting node may avoid transmitting in the channel.

[0065] LBT can be based on energy detection (ED) or signal detection. For LBT based on energy detection, when the signal energy measured from the channel is lower than the threshold, LBT generates a pass. On the contrary, when the signal energy measured from the channel exceeds the threshold, LBT generates a failure. For LBT based on signal detection, when a channel reservation signal (e.g., a predetermined preamble signal) is not detected in the channel, LBT generates a pass. In addition, LBT can be in multiple modes. The LBT mode can be, for example, Category 4 (CAT4) LBT, Category 2 (CAT2) LBT, or Category 1 (CAT1) LBT. CAT1LBT is referred to as a non-LBT mode, in which LBT will not be performed before transmission. CAT2LBT refers to LBT without a random backoff period. For example, a transmitting node can determine a channel measurement in a time interval and determine whether the channel is available based on a comparison of the channel measurement with the ED threshold. CAT4LBT refers to an LBT with a random backoff and a variable contention window (CW). For example, a transmitting node can extract a random number and back off a duration in a certain time unit based on the extracted random number.

[0066] In some aspects, network 100 may support independent sidelink communications between UEs 115 over a shared radio frequency band, wherein a subset of UEs 115 are adapted as anchor nodes (e.g., sidelink anchor UEs) and autonomously initiate sidelink operations for UEs 115. In this regard, the sidelink anchor UEs are autonomous and may perform sidelink operations independent of any cell (such as BS 105).

[0067] In order to target Figure 1For simplicity of explanation of the rest of the description, the UE 115 configured as an anchor node is referred to as an "anchor UE" or a "sidelink anchor UE", and the remaining UEs 115 configured to receive system information from the anchor UE are referred to as "client UEs". In some examples, UE 115j may represent an anchor UE, and UE 115k may represent a client UE (for simplicity of illustration and discussion herein, focus on one), however, without departing from the scope of the present disclosure, in corresponding implementations, the remaining UEs 115 may individually act as anchor UEs and / or client UEs.

[0068] The anchor UE may determine the system parameter information autonomously (eg, independent of any in-coverage cell and / or associated core network). Figure 1 In some embodiments, the system parameter information may be substantially the same between UEs 115j, 115d in the system to facilitate coordinated deployment (e.g., IIoT), or in other embodiments the system information may be at least partially different for deployment of different applications.

[0069] In some embodiments, the anchor UE may also send synchronization signals (e.g., including PSS and SSS) in the network 100 to initiate sidelink operations in the network 100 and facilitate synchronization with client UEs (e.g., 115k) that decide to join the sidelink operation. In addition, the anchor UE may broadcast system parameter information associated with the network 100 (e.g., including a sidelink master information block (e.g., SL-MIB) and / or remaining minimum system information (e.g., RMSI)) to facilitate sidelink communications between client UEs and with the anchor UE. In some cases, the anchor UE may broadcast the PSS, SSS, and / or SL-MIB in the form of a sidelink synchronization signal block (e.g., S-SSB) on a physical sidelink broadcast channel (e.g., PSBCH).

[0070] After obtaining the SL-MIB and / or RMSI, the client UE may perform a sidelink communication procedure to establish a sidelink connection with the anchor UE. For example, the anchor UE may allocate radio resources to the client UE for sidelink communication via information included in the RMSI. The anchor UE may also send additional system parameters, such as a reverse link grant (e.g., scheduling information), to the client UE. The additional system parameters may be sent in the form of a block (e.g., aggregating multiple reverse link grants for corresponding multiple client UEs) included in the sidelink control information (SCI), as described in more detail below.

[0071] Further, in some aspects, the anchor UE 115 can provide sidelink communications that allow the anchor UE 115 to communicate with the client UE 115 and allow the first client UE 115 to communicate with the second client UE 115 without tunneling through the BS 105 and / or the core network. A pair of UEs (such as an anchor UE 115 and a client UE or a pair of client UEs 115) can communicate with each other on the sidelink in the forward link direction and the reverse link direction. The anchor US 115 can support reverse sidelink communications, wherein the anchor UE 115 (e.g., a receiving UE) can initiate a sidelink transmission, for example, by sending a reverse link grant to the client UE 115 (e.g., a sending UE). In response to receiving the reverse link grant, the client UE 115 can send sidelink data to the anchor UE based at least in part on information included in the reverse link grant (such as scheduling information). In this regard, a receiving UE is understood to be a UE that receives data (e.g., on a PSSCH) from another UE in a sidelink communication, and a transmitting UE is understood to be a UE that transmits data (e.g., on a PSSCH) to another UE in a sidelink communication. Over time, a single UE may be both a receiving UE and a transmitting UE. For example, in an initial sidelink communication, a UE may be a receiving UE, while in a later sidelink communication, the same UE may be a transmitting UE, and vice versa.

[0072] Figure 2 1 shows an example of a wireless communication network 200 that provides sidelink communications according to an embodiment of the present disclosure. The network 200 may correspond to at least a portion of the network 100. Although for the purpose of simplifying the discussion, Figure 2 BS 205 and six UEs 215 (shown as 215a1, 215a2, 215a3, 215b1, 215b2, and 215b3) are shown, but it will be appreciated that embodiments of the present disclosure may be scaled to any suitable number of UEs 215 and / or BS 205. BS 205 and UE 215 may be similar to BS 105 and UE 115, respectively. BS 205 and UE 215 may share the same radio frequency band (or at least a sub-band thereof) for communication. In some cases, the radio frequency band may be a 2.4 GHz unlicensed band, a 5 GHz unlicensed band, or a 6 GHz unlicensed band (or some other band, such as FR2). Generally, the shared radio frequency band may be at any suitable frequency.

[0073] BS 205 and UE 215a1-215a3 may be operated by a first network operation entity. UE 215b1-215b3 may be operated by a second network operation entity. In some aspects, the first network operation entity may utilize the same RAT as the second network operation entity. For example, the BS 205 and UE 215a1-215a3 of the first network operation entity and the UE 215b1-215b3 of the second network operation entity are NR-U devices. In some other aspects, the first network operation entity may utilize a different RAT from the second network operation entity. For example, the BS 205a and UE 215a1-215a3 of the first network operation entity may utilize NR-U technology, while the UE 215b1-215b3 of the second network operation entity may utilize WiFi or LAA technology.

[0074] In network 200, some UEs in UE 215a1-215a3 and / or UE 215b1-215b3 can communicate with each other in peer-to-peer communication. For example, UE 215a1 can communicate with UE 215a2 on sidelink 252, UE 215a1 can communicate with UE 215a3 on another sidelink 251, UE 215b1 can communicate with UE 215b2 on another sidelink 254, and UE 215b1 can communicate with UE 215b3 on sidelink 256. Sidelinks 251, 252, 254 and 256 are unicast bidirectional links. Some UEs in UE 215 can also communicate with BS 205 in UL direction and / or DL ​​direction via communication link 253. For example, UE 215a1 and 215a3 are within the coverage area 210 of BS 205 and can therefore communicate with BS 205. UE 215a2 is outside the coverage area 210 and may therefore not communicate directly with BS 205. In some cases, UE 215a1 may operate as a repeater for UE 215a2 to reach BS 205. As an example, some of UEs 215 may be associated with vehicles (e.g., similar to UE 115i-k), and the communications on sidelinks 251, 252, 254, and 256 may be C-V2X communications. C-V2X communications may refer to communications between a vehicle and any other wireless communication device in a cellular network. This is merely exemplary, as the sidelink may be between any of a variety of different UE types and communications.

[0075] Further, as discussed above, the network 200 may support independent sidelink communications between UEs 215 over a shared radio frequency band, wherein a subset of the UEs 215 are adapted as anchor nodes (e.g., anchor UEs) and autonomously initiate sidelink operations for the UEs 215. In this regard, the sidelink anchor UEs are autonomous and may perform sidelink operations independent of any cell (such as BS 205). There may be several scenarios in which there may be a use for UE 215 to become an anchor UE to perform sidelink specific operations: (i) in multi-cell coverage, where the client UE (e.g., receiving UE) is located in a different asynchronous cell relative to the sidelink transmitting UE; (ii) in partial coverage, where the client UE (such as UE 215a2) is out of coverage and may need to acquire synchronization from a sidelink transmitting UE (such as UE 215a1) in coverage; and / or (iii) out of coverage, where two sidelink UEs (such as UE 215b1 and UE 215b2) are both out of coverage of the cell and the sidelink transmitting UE (e.g., UE 215b1) decides to act as a reference synchronization source (referred to as the anchor UE).

[0076] In any case, the anchor UE (such as 215a1 and 215b1) can send system parameter information so that the client UEs (such as 215a2-3 and 215b2-3) can receive and recover resource allocation and timing information, respectively, to facilitate sidelink communications with the anchor UE. In addition, as described in more detail below, the anchor UE can send one or more reverse link grants aggregated into subchannels so that the client UE can initiate sidelink transmissions with the anchor UE based on the information included in the reverse link grant.

[0077] Figure 3 A sidelink communication scheme 300 according to some aspects of the present disclosure is shown. Scheme 300 may be employed by a UE (such as UE 115 and / or 215) in a network (such as network 100 and / or 200). Specifically, a sidelink UE may employ scheme 300 to engage in sidelink communications on a shared radio frequency band (e.g., in a shared spectrum or an unlicensed spectrum). Figure 3 In , the x-axis represents time in some arbitrary units, and the y-axis represents frequency in some arbitrary units.

[0078] In the scheme 300, a shared radio frequency band 301 is divided in frequency into a plurality of sub-channels or frequency sub-bands 302 (shown as 302 S0 ,302 S1 ,302 S2, ...), and is divided in time into a plurality of sidelink time slots or frames 304 (shown as 304a, 304b, 304c, 304d, ...) for sidelink communications. Frequency band 301 can be at any suitable frequency (e.g., at approximately 2.4 GHz, 5 GHz or 6 GHz, mmW range, etc.). Frequency band 301 can have any suitable BW and can be divided into any suitable number of frequency sub-bands 302. The number of frequency sub-bands 302 can depend on the sidelink communication BW requirements. In one example, frequency band 301 is a 2.4 GHz unlicensed band and can have a bandwidth of approximately 80 megahertz (MHz), which is divided into approximately 15 5 MHz frequency sub-bands 302.

[0079] A sidelink UE (eg, UE 115 and / or 215) may be equipped with a wideband receiver and a narrowband transmitter. For example, the UE may utilize a narrowband transmitter to access frequency subband 302. S2 , to utilize the frame structure 304 for sidelink transmission. The frame structure 304 may be repeated in each frequency sub-band 304. In some cases, there may be frequency gaps or guard bands between adjacent frequency sub-bands, such as Figure 3 , for example, to mitigate adjacent frequency band interference. Thus, multiple sidelink data (e.g., FDM) can be transmitted simultaneously in different frequency sub-bands 302. Frame structure 304 can also repeat in time. For example, frame structure 304 can be used to separate frequency sub-bands 302. S2 Divided into multiple frames in time.

[0080] The frame structure 304 includes sidelink resources 306 in each frequency subband 302. Legend 305 indicates some of the types of sidelink channels within the sidelink resources 306. The sidelink resources 306 may have a structure substantially similar to the NR sidelink resources. For example, the sidelink resources 306 may include multiple resource elements (REs) in frequency (which may include multiple subcarriers) and multiple symbols in time. In some cases, the sidelink resources 306 may have a duration between approximately one millisecond (ms) and approximately 20 ms. Each sidelink resource 306 may include a PSCCH 310 and a PSSCH 320. The PSCCH 310 and the PSSCH 320 may be multiplexed in time and / or frequency. Figure 3In the example shown, for each sidelink resource 306, the PSCCH 310 is located during the starting symbol (e.g., approximately 1 symbol or approximately 2 symbols) of the sidelink resource 306 and occupies a portion of the corresponding frequency subband 302, and the PSSCH 320 occupies the remaining time-frequency resources in the sidelink resource 306. Further, as shown in the figure, the PSCCH 310 may not occupy the entire frequency band / subband, but rather a portion of it. This means that the PSSCH 320 may also occupy a portion of one or more symbols of the frequency band / subband in the previous symbols of the time frame (such as a time slot). In some cases, the sidelink resource 306 may also include a physical sidelink feedback channel (PSFCH), for example, located during the ending symbol of the sidelink resource 306, such as Figure 4 In general, PSCCH 310, PSSCH 320, and / or PSFCH may be multiplexed within sidelink resources 306 in any suitable configuration.

[0081] In some aspects, the scheme 300 is used to synchronize sidelink communications. In other words, the sidelink UE is synchronized in time and aligned in terms of symbol boundaries, sidelink resource boundaries (e.g., the start time of the sidelink frame 304). The sidelink UE can perform synchronization in various forms, for example, based on a sidelink SSB received from the sidelink UE and / or a NR-U SSB received from the BS when within the coverage of the BS (e.g., BS 105 and / or 205). In some aspects, for example, the sidelink UE can be preconfigured with a resource pool 308 in the frequency band 301. The resource pool 308 can include a plurality of sidelink resources 306.

[0082] As discussed above, the subject technology provides a sidelink UE configured as a sidelink anchor UE (e.g., 115j, 215a1, 215b1), which is used to configure resource allocations to other client UEs. In this way, the sidelink anchor UE can configure the client UE with a resource pool configuration indicating resources in the frequency band 301 and / or subband 302 and / or timing information associated with the sidelink frame 304. For example, the sidelink anchor UE can provide resource allocation information to the client UE. In some aspects, the sidelink anchor UE can transmit a transmit resource pool configuration in an RMSI, wherein the transmit resource pool configuration indicates which radio resources are allocated to the sidelink anchor UE for the sidelink anchor UE to transmit sidelink communications. In some aspects, the sidelink anchor UE can transmit a receive resource pool configuration in an RMSI, wherein the receive resource pool configuration indicates which radio resources are allocated to the sidelink anchor UE for the sidelink anchor UE to receive sidelink communications (e.g., via a reverse link). In this regard, the client UE may receive and decode a physical communication channel (e.g., PSCCH 310, PSCCH 320) from the sidelink anchor UE based on the transmit resource pool configuration, and encode and send PSCCH 310 and PSCCH 320 to the sidelink anchor UE based on the receive resource pool configuration.

[0083] Figure 4 4 is a simplified block diagram of an exemplary sidelink resource slot 400 that may be used to send one or more reverse link grants according to some aspects of the present disclosure. The sidelink resource slot 400 includes PSCCH 310, PSCCH 320, physical sidelink feedback channel (PSFCH) 402, symbol gap 404 (e.g., time gap), and DMRS 406 to illustrate various aspects of the present disclosure. In addition, Figure 4 Symbols 408 in time of sidelink resource slots 400 are shown. However, not all depicted sidelink resource channels and / or fields may be required, and one or more implementations may include additional channels and / or fields not shown in the figure. The arrangement and type of sidelink resource channels and / or fields may be changed without departing from the scope of the claims set forth herein. Additional, different or fewer channels and / or fields may be provided.

[0084] In sidelink communications, for a client UE (e.g., Figure 2 If one or more of the client UEs 215a2-3 and 215b2-3 shown in FIG. 1 successfully parses and / or decodes PSCCH 310 and PSCCH 320, a description of the sidelink anchor UE (e.g., in FIG. 1 ) may be carried in the sidelink control information SCI. Figure 2The sidelink UE 215a1 or 215b1 may be used to assign specific resources and transmission configurations for transmission to one or more of the anchor UEs 215a1 or 215b1 shown in FIG. 2 . In this regard, the control information for the sidelink communication may be transmitted in the form of an SCI message. The SCI may inform the client UE of the resource reservation interval, the frequency location of the initial transmission and retransmission, the time interval between the initial transmission and the retransmission, and the modulation and coding scheme (MCS) used to modulate the data sent on the PSSCH 320, as well as other information.

[0085] In some embodiments, the SCI may include a frequency hopping flag field, a resource block assignment and a frequency hopping resource allocation field, a time resource mode field, an MCS field, a timing advance field and / or a beta offset field, and a group destination identifier field. The SCI may include other additional fields suitable for supporting control signaling (such as for V2X, etc.). The time resource mode field may provide time domain resource allocation for a data channel (e.g., PSSCH 320) and specifically potential symbols for PSSCH transmission. The MCS field may provide an MCS for PSSCH 320, which may be selected autonomously by the sidelink anchor UE. The timing advance field and / or the beta offset field may provide a sidelink time adjustment. The group destination identifier field may indicate a group of client UEs that are potentially interested in messages sent from the sidelink anchor UE. This may be used by the client UE to ignore messages destined for other groups of client UEs. In addition, in some embodiments, the SCI may include one or more reverse link grants that may provide scheduling information so that the corresponding client UE may send sidelink communications to the anchor UE based at least in part on the information included in the reverse link grant, as described in more detail below. In addition to including one or more reverse link grants themselves, the SCI may include: one or more data fields configured to identify the number of reverse link grants included in the SCI and / or the size of a block including the reverse link grants; one or more identifiers corresponding to each of the reverse link grants; and one or more identifiers corresponding to client UEs associated with the reverse link grants; and other fields.

[0086] In some aspects, the SCI may be processed using transport channel coding to generate an SCI message transport block, which may then be processed using physical channel coding to generate a corresponding PSCCH block. The PSCCH block is carried on a corresponding symbol for transmission. The client UE may receive one or more resource units on the corresponding symbol to recover the control signaling information, and may extract the data channel allocation and transmission configuration. Further, as described above, the SCI may be sent in stages on PSCCH 310 and PSCCH 320.

[0087] For example, PSCCH 310 may be used to carry a first stage SCI (SCI-1). PSSCH 320 may be used to carry a second stage SCI (SCI-2) and / or a third stage SCI (SCI-3). In some embodiments, SCI-2 and / or SCI-3 carried on PSSCH 320 may include blocks of reverse link grants for multiple client UEs, as described in more detail below. PSSCH 320 may additionally carry sidelink data (e.g., forward link data). According to some embodiments of the present disclosure, SCI-1 may carry one or more flags and / or information bits indicating whether PSSCH carries forward link data, which the client UE may use to determine whether PSSCH will have only rate-matched SCI-2 and / or SCI-3 data or a combination of SCI-2 and / or SCI-3 data and forward link (sidelink) data. Sidelink data (if present) may be in various forms and types, depending on the sidelink application. For example, when the sidelink application is a V2X application, the sidelink data may carry V2X data (e.g., vehicle position information, driving speed and / or direction, vehicle sensing measurements, etc.). Alternatively, when the sidelink application is an IIoT application, the sidelink data may carry IIoT data (e.g., sensor measurements, device measurements, temperature readings, etc.). The PSFCH 402 may be used to carry feedback information, such as HARQ ACK / NACK for sidelink data received in an earlier sidelink resource 306.

[0088] The SCI may also indicate scheduling information and / or a destination identifier (ID) identifying a target client UE for the next sidelink resource 306. For example, this may be included in SCI-2. When an SCI is detected in the sidelink resource 306, the sidelink UE may determine whether the sidelink UE is the target receiver based on the destination ID. If the sidelink UE is the target receiver, the sidelink UE may continue to receive and decode the sidelink data indicated by the SCI. In some aspects, multiple sidelink UEs may transmit sidelink data in the sidelink frame 304 simultaneously in different frequency subbands (e.g., via FDM). For example, in the sidelink frame 304b, a pair of sidelink UEs may use frequency subband 302a to transmit sidelink data to the sidelink frame 304b. S2 The sidelink resource 306 in the frequency subband can be used to transmit sidelink data, while another pair of sidelink UEs can use the frequency subband 302 S1 The sidelink resources 306 in are used to transmit sidelink data.

[0089] Figure 55 is a block diagram of an exemplary client UE 500 (eg, a non-anchor UE) according to some aspects of the present disclosure. For example, the client UE 500 may be the client UE described above in Figure 1 1 or 115 in the network 100 discussed above. Figure 2 As shown, the client UE 500 may include a processor 502, a memory 504, a sidelink communication module 508, a transceiver 510 including a modem subsystem 512 and a radio frequency (RF) unit 514, and one or more antennas 516. These elements may communicate directly or indirectly with each other, for example, via one or more buses.

[0090] The processor 502 may include a central processing unit (CPU), a digital signal processor (DSP), an application specific integrated circuit (ASIC), a controller, a field programmable gate array (FPGA) device, another hardware device, a firmware device, or any combination thereof configured to perform the operations described herein. The processor 502 may also be implemented as a combination of computing devices, for example, a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

[0091] The memory 504 may include cache memory (e.g., cache memory of the processor 502), random access memory (RAM), magnetoresistive RAM (MRAM), read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), flash memory, a solid-state memory device, a hard drive, other forms of volatile and non-volatile memory, or a combination of different types of memory. In one aspect, the memory 504 includes a non-transitory computer-readable medium. The memory 504 may store or have stored thereon instructions 506. The instructions 506 may include, when executed by the processor 502, causing the processor 502 to perform aspects of the present disclosure described herein (e.g., Figure 1-4 506 may also be referred to as program code. The program code may be used to cause the wireless communication device to perform the operations, for example, by causing one or more processors (such as processor 502) to control or command the wireless communication device to do so. The terms "instructions" and "code" should be broadly interpreted to include any type of computer-readable statements. For example, the terms "instructions" and "code" may refer to one or more programs, routines, subroutines, functions, processes, etc. "Instructions" and "code" may include a single computer-readable statement or multiple computer-readable statements.

[0092] The sidelink communication module 508 may be implemented via hardware, software, or a combination thereof. For example, the sidelink communication module 508 may be implemented as a processor, circuitry, and / or instructions 506 stored in the memory 504 and executed by the processor 502. In some cases, the sidelink communication module 508 may be integrated within the modem subsystem 512. For example, the sidelink communication module 508 may be implemented by a combination of software components (e.g., executed by a DSP or general purpose processor) and hardware components (e.g., logic gates and circuits) within the modem subsystem 512.

[0093] The sidelink communication module 508 can be used in various aspects of the present disclosure (e.g., Figure 1-4 and aspects of 7-15). In some aspects, the sidelink communication module 508 is adapted to monitor one or more SCI transmissions to receive a reverse link grant from an anchor UE, and in response to receiving a reverse link grant, initiate sidelink communication with the anchor UE based in part on the reverse link grant. According to an embodiment of the present disclosure, this may include receiving an SCI-1 transmission from an anchor UE, the SCI-1 transmission indicating whether there is forward link data included in the PSSCH along with SCI-2 and / or SCI-3 data (which includes reverse link grants for multiple UEs (potentially including the client UE 500, which can be indicated, for example, by an identifier of the client UE 500)) and indicating whether the block of reverse link grants is in SCI-2 (in some embodiments) or in SCI-3 (in some embodiments). In embodiments in which the block of reverse link grants is included in SCI-3, SCI-2 may indicate parameters for SCI-3, including a block size, a number of clients for SCI-3, and potentially including an indication of the presence or absence of forward link data (instead of SCI-1 in some embodiments). The above and further below with respect to the remaining figures include details related to SCI-1, SCI-2 and / or SCI-3.

[0094] As shown, the transceiver 510 may include a modem subsystem 512 and an RF unit 514. The transceiver 510 may be configured to communicate bidirectionally with other devices, such as the BS 105. The modem subsystem 512 may be configured to modulate and / or encode data from the memory 504 and / or the sidelink communication module 508 according to a modulation and coding scheme (MCS) (e.g., a low-density parity check (LDPC) coding scheme, a turbo coding scheme, a convolutional coding scheme, a digital beamforming scheme, etc.). The RF unit 514 may be configured to process (e.g., perform analog-to-digital conversion or digital-to-analog conversion, etc.) the modulated / encoded data (e.g., SCI, sidelink data, synchronization signal, SSB, uplink data, etc.) from the modem subsystem 512 (for outbound transmissions) or the modulated / encoded data of a transmission originating from another source, such as the UE 115 or the BS 105. The RF unit 514 may also be configured to perform analog beamforming in conjunction with digital beamforming. Although shown as being integrated together in the transceiver 510, the modem subsystem 512 and the RF unit 514 may be separate devices that are coupled together at the UE 500 to enable the UE 500 to communicate with other devices.

[0095] The RF unit 514 may provide modulated and / or processed data (e.g., data packets (or more generally, data messages that may include one or more data packets and other information)) to the antenna 516 for transmission to one or more other devices. The RF unit 514 may process the modulated and / or processed data and generate a corresponding time domain waveform using SC-FDMA modulation before transmission via the antenna 516. In other cases, the RF unit 514 may generate a time domain waveform using OFDM modulation. The antenna 516 may also receive data messages sent from other devices. The antenna 516 may provide the received data message for processing and / or demodulation at the transceiver 510. The transceiver 510 may provide the demodulated and decoded data (e.g., sidelink configuration, SCI, sidelink data, SCI reservation conflict information, synchronization signal, SSB) to the sidelink communication module 508 for processing. The antenna 516 may include multiple antennas of similar or different designs to maintain multiple transmission links. The RF unit 514 may configure the antenna 516. In some aspects, the RF unit 514 may include various RF components, such as a local oscillator (LO), an analog filter, and / or a mixer. The LO and the mixer may be configured based on a specific channel center frequency. The analog filter may be configured to have a specific passband according to the channel BW. The RF components may be configured to operate in various power modes (e.g., normal power mode, low power mode, power-off mode), and may switch between different power modes according to the transmission and / or reception requirements at the client UE 500 and / or the anchor UE.

[0096] In one aspect, the client UE 500 may include multiple transceivers 510 that implement different RATs (e.g., NR and LTE). In one aspect, the client UE 500 may include a single transceiver 510 that implements multiple RATs (e.g., NR and LTE). In one aspect, the transceiver 510 may include various components, where different combinations of components may implement different RATs.

[0097] Figure 6 600 according to some aspects of the present disclosure. The anchor UE 600 may be as described above in Figure 1 1 or 115 in the network 100 discussed above. Figure 2 As shown, the anchor UE 600 may include a processor 602, a memory 604, an anchor sidelink configuration module 608, a transceiver 610 including a modem subsystem 612 and an RF unit 614, and one or more antennas 616. These elements may communicate directly or indirectly with each other, for example, via one or more buses.

[0098] The processor 602 may have various features as a type-specific processor. For example, these may include a CPU, a DSP, an ASIC, a controller, an FPGA device, another hardware device, a firmware device, or any combination thereof configured to perform the operations described herein. The processor 602 may also be implemented as a combination of computing devices, for example, a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

[0099] The memory 604 may include cache memory (e.g., cache memory of the processor 602), RAM, MRAM, ROM, PROM, EPROM, EEPROM, flash memory, solid-state memory devices, one or more hard disk drives, memristor-based arrays, other forms of volatile and non-volatile memory, or a combination of different types of memory. In some aspects, the memory 604 includes a non-transitory computer-readable medium. The memory 604 may store instructions 606. The instructions 606 may include: when executed by the processor 602, cause the processor 602 to perform the operations described herein (e.g., Figure 1-4 Instructions 606 may also be referred to as code, which may be broadly interpreted as including any type of computer-readable statements, such as those described above. Figure 5 discussed.

[0100] The anchor sidelink configuration module 608 may be implemented via hardware, software, or a combination thereof. For example, the anchor sidelink configuration module 608 may be implemented as a processor, circuit, and / or instructions 606 stored in the memory 604 and executed by the processor 602. In some examples, the anchor sidelink configuration module 608 may be integrated within the modem subsystem 612. For example, the anchor sidelink configuration module 608 may be implemented by a combination of software components (e.g., executed by a DSP or general purpose processor) and hardware components (e.g., logic gates and circuits) within the modem subsystem 612.

[0101] The anchor side link configuration module 608 may be used in various aspects of the present disclosure (eg, Figure 1-4and aspects of 7-15). For example, the anchor sidelink configuration module 608 is configured to determine one or more reverse link grants and send them to one or more client UEs. According to an embodiment of the present disclosure, this may include configuring an SCI-1 transmission that indicates whether there is forward link data included in the PSSCH along with SCI-2 and / or SCI-3 data (which includes reverse link grants for multiple client UEs). The anchor sidelink configuration module 608 may also determine a block of reverse link grants to be sent for one or more client UEs in a given time frame, and place these reverse link grants into blocks for transmission. The anchor sidelink communication module 608 may place the block of reverse link grants in SCI-2 (in some embodiments) or SCI-3 (in some examples). In embodiments where blocks of reverse link grants are included in SCI-3, the anchor sidelink communications module 608 may also include in SCI-2 an indication of parameters for SCI-3, including block size, number of clients for SCI-3, and potentially an indication of the presence or absence of forward link data (instead of SCI-1 in some embodiments). The above and further below with respect to the remaining figures include details related to SCI-1, SCI-2, and / or SCI-3.

[0102] As shown, the transceiver 610 may include a modem subsystem 612 and an RF unit 614. The transceiver 610 may be configured to communicate bidirectionally with other devices (such as UE 115 and / or 600 and / or another core network element). The modem subsystem 612 may be configured to modulate and / or encode data according to an MCS (e.g., an LDPC coding scheme, a turbo coding scheme, a convolutional coding scheme, a polarization coding scheme, a digital beamforming scheme, etc.). The RF unit 614 may be configured to process (e.g., perform analog-to-digital conversion or digital-to-analog conversion, etc.) modulated / encoded data (e.g., PDCCH, PDSCH, SSB, sidelink configuration, sidelink resource pool configuration, SSB, frequency hopping pattern for sidelink communication, PSCCH, PSSCH, etc.) from the modem subsystem 612 (for outbound transmission) or modulated / encoded data originating from another source (such as UE 115 and / or BS 105) for transmission. The RF unit 614 may also be configured to perform analog beamforming in conjunction with digital beamforming.Although shown as being integrated together in the transceiver 610, the modem subsystem 612 and / or the RF unit 614 may be separate devices that are coupled together at the UE 600 to enable the UE 600 to communicate with other devices.

[0103] The RF unit 614 may provide modulated and / or processed data (e.g., data packets (or more generally, data messages that may include one or more data packets and other information)) to the antenna 616 for transmission to one or more other devices. The RF unit 614 may process the modulated and / or processed data and generate a corresponding time domain waveform using SC-FDMA modulation before transmission via the antenna 616. In other cases, the RF unit 614 may generate the time domain waveform using OFDM modulation. The antenna 616 may also receive data messages sent from other devices and provide the received data messages for processing and / or demodulation at the transceiver 610. The transceiver 610 may provide the demodulated and decoded data to the anchor side link configuration module 608 for processing. The antenna 616 may include multiple antennas of similar or different designs to maintain multiple transmission links.

[0104] In one aspect, the anchor UE 600 may include multiple transceivers 610 that implement different RATs (e.g., NR and LTE). In one aspect, the anchor UE 600 may include a single transceiver 610 that implements multiple RATs (e.g., NR and LTE). In one aspect, the transceiver 610 may include various components, where different combinations of components may implement different RATs.

[0105] Mechanisms for sending one or more reverse link grants in the form of SCIs (eg, using SCI-1 via PSCCH, SCI-2 via PSSCH, and / or SCI-3 via PSSCH) are described in greater detail herein.

[0106] Figure 7 700 is a flowchart of a first reverse link grant transmission process according to some aspects of the present disclosure. Various aspects of process 700 may be performed by a computing device (e.g., a processor, a processing circuit, and / or other suitable components) of a wireless communication device or other suitable units for performing these steps. For example, a wireless communication device (such as UE 115, 215, and / or 600) may utilize one or more components (such as a processor 602, a memory 604, an anchor side link communication module 608, a transceiver 610, a modem 612, and one or more antennas 616) to perform the steps of process 700. As shown, process 700 includes multiple enumerated steps, but various aspects of process 700 may include additional steps before, after, and between the enumerated steps. In some aspects, one or more of the enumerated steps may be omitted or performed in a different order.

[0107] At block 702, an anchor UE (e.g., UE 600) may determine one or more reverse link grants for transmission, such as multiple reverse link grants for corresponding multiple client UEs. In some aspects, the anchor UE 600 may determine the reverse link grant based in part on a scheduling condition at the anchor UE 600. For example, the anchor sidelink communication module 608 may be configured to determine one or more reverse link grants based on sidelink channel information (e.g., channel quality information (CQI) and / or channel sensing information). Additionally or alternatively, the anchor UE 600 may determine the reverse link grant based at least in part on a transmission delay between a certain client UE 500 and the anchor UE 600. Each reverse link grant may correspond to a specific client UE 500. Accordingly, the reverse link grant may be configured to provide scheduling information so that the anchor UE 600 may successfully receive a corresponding transmission from the client UE 500 to the anchor UE 600.

[0108] At block 704, the anchor UE 600 may transmit the first stage control information (SCI-1) on the PSCCH. For example, the anchor UE 600 may use the transceiver 610 to transmit the SCI-1. Figure 4 As described, SCI-1 may include resource allocation information and additional fields. In addition, in some aspects, SCI-1 may include information related to the second stage control information (SCI-2). For example, SCI-1 may include the size of SCI-2 and information about parsing SCI-2. Further, in some aspects, SCI-1 may indicate whether the PSSCH includes sidelink data (e.g., user data and / or forward link data), as described in more detail below (e.g., such as having a dedicated flag for this purpose, etc.).

[0109] At block 706, the anchor UE 600 may send an SCI-2 rate-matched according to a rate matching rule on the PSSCH 320. As described herein, the term "rate matching" may refer to the process of resizing and / or modulating data to fit in a specific block of time-frequency elements (such as available resource elements for the PSSCH within a time frame such as a time slot according to an embodiment of the present disclosure). In some aspects, the SCI-2 includes the reverse link grant determined at block 702. Further, after determining the reverse link grant, the anchor UE 600 may aggregate the reverse link grant into blocks. Accordingly, the SCI-2 may include the reverse link grant in a single data block. The SCI-2 may also include information for decoding the PSSCH 320. For example, the SCI-2 may include a destination identifier identifying the corresponding client UE 500, and the SCI-2 may include a source identifier identifying the anchor UE 600. In any case, the SCI-2 may be rate matched according to the rate matching rules so that the SCI-2 occupies specific resource elements and / or symbols of the PSSCH 320. For example, in the case where the DMRS in the PSSCH is not transmitted at the beginning of the PSSCH in a given time slot, the anchor UE 600 may rate match the SCI-2 from the beginning of the PSSCH (and around the DMRS). As another example (where the DMRS is not transmitted at the beginning of the PSSCH), the anchor UE 600 may rate match the SCI-2 from the beginning of the DMRS and, upon reaching the end of the time slot, return to the beginning of the PSSCH within the time slot. These examples and other examples are discussed in more detail further below with respect to other figures.

[0110] For example, now go to Figure 8 , in some embodiments (where the DMRS does not start at the beginning of the PSSCH), the SCI-2 sent on the PSSCH 806 may be rate matched according to a first rate matching rule. According to the first rate matching rule, the SCI-2 may be rate matched from the beginning 802 of the PSSCH 806. As used herein, the term "start of the PSSCH", the term "first resource element of the PSSCH", and the term "first resource element after the PSCCH" may refer to the first time-frequency resource (e.g., a combination of a subcarrier and a symbol) in the PSSCH and may be interchangeable.

[0111] Further, as shown by the block diagram of an exemplary first sidelink resource 800 with one or more reverse link grants, the SCI-2 can be rate matched to occupy any resource element that is available (e.g., unoccupied) after the start 802 of the PSSCH 806. To this end, the SCI-2 can be rate matched to occupy continuous resource elements from the start 802 to the end of the PSSCH 806. In addition, the rate matched SCI-2 can overlap with (e.g., be interspersed with) the DMRS 406. Therefore, in some embodiments, when the PSSCH 806 lacks user data and the DMRS 406 is sent after the first resource element of the PSSCH 320, the SCI-2 can be rate matched according to the first rate matching rule.

[0112] In addition, because user data is not included on the PSSCH 320, the transmission of the sidelink resources 800 can be dedicated to information associated with the reverse link grant included in the SCI-2. To this end, the anchor UE 600 can send each portion of the sidelink resources 800 (e.g., SCI-1 on the PSCCH 804, SCI-2 on the PSCCH 806, etc.), regardless of whether the anchor UE 600 has forward link data to be sent to a particular client UE 500. Further, in some embodiments, the SCI-1 can include an additional data field configured to indicate whether the PSSCH 806 includes user data (i.e., forward link data). Therefore, as described in more detail below, the SCI-1 on the PSCCH 804 can indicate whether the transmission of the sidelink resources 800 is dedicated to information associated with the reverse link grant or also includes user data.

[0113] Fig. 9 is a flow chart of an exemplary embodiment for sending SCI-2 according to a rate matching rule. More specifically, Fig. 9 An embodiment of performing block 706 according to a second rate matching rule is shown. Accordingly, consistent with the description above, aspects involved in performing block 706 may be performed by a computing device (e.g., a processor, a processing circuit, and / or other appropriate components) of a wireless communication device or other appropriate units for performing these steps. For example, a wireless communication device (such as UE115, 215, and / or 600) may utilize one or more components (such as a processor 602, a memory 604, an anchor sidelink communication module 608, a transceiver 610, a modem 612, and one or more antennas 616) to perform various aspects of block 706. As shown, block 706 includes a plurality of enumerated steps, but various aspects of block 706 may include additional steps before, after, and between the enumerated steps. In some aspects, one or more of the enumerated steps may be omitted or performed in a different order.

[0114] Now refer to box 900 and Fig.10 , the anchor UE 600 may rate match the first portion of the SCI-2 1001 in a second time period 1002 (eg, the second symbol set 408) of the PSSCH 320. The second time period 1002 may start from the start of the DMRS 406, for example.

[0115] like Fig.10 As shown, in some embodiments, the anchor UE 600 may send SCI-1 in the PSCCH 804 in a first time period 1004. As shown, the first time period 1004 occurs in time before the second time period 1002. After the first time period 1004, the anchor UE 600 may send the DMRS 406 in the second time period 1002 and begin rate matching the first portion of the SCI-2 1001 from the start of the DMRS 406. In some embodiments, the anchor UE 600 is configured to use the second matching rule when the PSSCH lacks user data and the DMRS 406 is sent after the first resource element of the PSSCH (e.g., after the start of the PSSCH 802).

[0116] exist Fig. 9 At block 902 of FIG. 1 , the anchor UE 600 may return to the first time period 1004 when rate matching SCI-2 in the PSSCH, as shown in FIG. Fig.10 In such an embodiment, the resource elements of the PSSCH within the first time period 1004 (including the start 802 of the PSSCH) may be available (e.g., unoccupied and / or unreserved). To this end, the anchor UE 600 may be configured to return to the start 802 of the PSSCH when in the process of rate matching the SCI-2 according to the second rate matching rule.

[0117] exist Fig. 9At block 904 of , the anchor UE 600 may rate match the second portion 1008 of the SCI-2 from the start 802 of the PSSCH (e.g., the first resource element after the PSCCH) in the first time period 1004 to fill the resource elements of the PSSCH in the first time period 1004 with the second portion 1008 of the SCI-2 (e.g., the remaining portion of the SCI-2). In some embodiments, the anchor UE 600 may rate match the second portion 1008 of the SCI-2 from the start 802 of the PSSCH to the start of the DMRS signal 406 in the second time period 1002. Thus, in some embodiments, the anchor UE 600 may rate match the second portion 1008 of the SCI-2 as part of general rate matching of the SCI-2 as a whole, so that the second portion 1008 of the SCI-2 occupies available resource elements of the PSSCH in the first time period 1004.

[0118] From the above discussion, it can be seen that Fig.10 , the first portion 1001 of the SCI-2 may include data (such as the first portion of a block of reverse link grants) that is configured to be decoded and / or parsed before proceeding to the remainder of the reverse link grant included in the second portion 1008 of the SCI-2. That is, for example, although the data in the second portion 1008 of the SCI-2 may be sent at an earlier time, the client UE 500 may read and / or decode the data in the first portion 1001 of the SCI-2 chronologically before the data in the second portion 1008 of the SCI-2, and thus save it until the complete SCI-2 at the client UE 500 is available for further processing.

[0119] Furthermore, because in this example, user data is not included on the PSSCH, transmissions of the sidelink resources 1000 may be dedicated to information associated with the reverse link grant included in SCI-2. To this end, the anchor UE 600 may transmit each portion (e.g., SCI-1, SCI-2) of the sidelink resources 1000 regardless of whether a forward link transmission occurs on the sidelink (e.g., 251, 252, 254, 256) and / or is directed to a particular client UE 500 (thereby, for example, reducing latency).

[0120] Fig.111 is a flow chart of a second reverse link grant transmission process 1100 according to some aspects of the present disclosure. Aspects of process 1100 may be performed by a computing device (e.g., a processor, processing circuitry, and / or other appropriate components) of a wireless communication device or other appropriate means for performing such steps. For example, a wireless communication device (such as UE 115, 215, and / or 600) may utilize one or more components (such as processor 602, memory 604, anchor sidelink communication module 608, transceiver 610, modem 612, and one or more antennas 616) to perform the steps of process 1100. Process 1100 may be at least partially implemented as described above with respect to Figure 7 Similar mechanisms in the process 700 discussed. As shown, process 1100 includes a plurality of enumerated steps, but aspects of process 1100 may include additional steps before, after, and between the enumerated steps. In some aspects, one or more of the enumerated steps may be omitted or performed in a different order.

[0121] At block 1102, the anchor UE 600 may determine one or more reverse link grants. As described above with reference to process 700, the anchor UE 600 may determine the reverse link grant based in part on the scheduling conditions at the anchor UE 600. For example, the anchor sidelink communication module 608 may be configured to determine one or more reverse link grants based on sidelink channel information (e.g., CQI and / or channel sensing information). Additionally or alternatively, the anchor UE 600 may determine the reverse link grant based at least in part on the transmission delay between a given client UE 500 and the anchor UE 600. Each reverse link grant may correspond to a particular client UE 500. Accordingly, the reverse link grant may be configured to provide scheduling information so that the anchor UE 600 may successfully receive the corresponding transmission from the client UE 500 to the anchor UE 600.

[0122] At box 1104, the anchor UE may send SCI-1 on the PSCCH. In some embodiments, SCI-1 may include a data field (e.g., a flag and / or bit modified from another data field or a new data field) that is configured to indicate whether the PSSCH (e.g., the sidelink resources 400, 800, 1000 shown in the various figures) includes user data (e.g., sidelink data and / or forward link data). For example, the data field may be set to a first state to indicate the absence of user data on the PSSCH, and the data field may be set to a different second state to indicate the presence of user data on the PSSCH. In addition, SCI-1 may include any appropriate data field, such as a data field configured to indicate the size of SCI-2, a data field configured to indicate resource allocation, and / or the above-referenced data field. Figure 4Describes the data fields, and other fields.

[0123] At decision block 1106, the anchor UE 600 may determine that the DMRS 406 is at the start of the PSSCH (eg, Figure 8 In some embodiments, the anchor UE 600 may be preconfigured to send the DMRS 406 at the start 802 of the PSSCH, while in other embodiments the anchor UE 600 may be preconfigured to send the DMRS 406 after a time interval (e.g., on the order of a few symbols), such as using Fig.10 4. In such an embodiment, the anchor UE 600 may determine whether the DMRS 406 is transmitted at the start 802 of the PSSCH based at least in part on the preconfigured settings of the anchor UE 600. Additionally or alternatively, the anchor UE 600 may determine whether the DMRS 406 is transmitted at the start 802 of the PSSCH based in part on the sidelink channel information.

[0124] In response to determining that DMRS 406 is transmitted at the start 802 of the PSSCH, process 1100 may proceed to block 1108. At block 1108, anchor UE 600 may transmit SCI-2 rate-matched from DMRS 406 on the PSSCH. In some embodiments, determining that DMRS 406 is transmitted at the start 802 of the PSSCH may involve determining that DMRS 406 is transmitted in the first symbol on the PSSCH. Thus, rate-matching SCI-2 from DMRS 406 may involve rate-matching SCI-2 from the first symbol of the PSSCH so that SCI-2 occupies any available resource element on the PSSCH starting from the first symbol of the PSSCH. If the PSSCH lacks user data (e.g., as indicated by a flag set in SCI-1), rate-matching SCI-2 from DMRS 406 may include rate-matching SCI-2 to each remaining resource element on the PSSCH. On the other hand, if the PSSCH includes user data (e.g., as indicated by a flag in SCI-1), one set of resource elements for the PSSCH may be reserved for the user data, and SCI-2 may be rate matched from DMRS 406 to a different set of resource elements that are not reserved for user data.

[0125] Returning to decision block 1106 , if the alternative anchor UE 600 determines that the DMRS 406 is not transmitted at the start 802 of the PSSCH, the process 1100 may proceed to decision block 1110 .

[0126] At decision block 1110, the anchor UE 600 determines whether the PSSCH includes user data (e.g., the anchor UE 600 may determine whether it has any user data to be sent via the forward link in the PSSCH in this time slot). If it is determined at decision block 1110 that there is no user data to be sent in the forward link with SCI-2, the process 1100 proceeds to block 1112.

[0127] At block 1112, the anchor UE 600 may send the SCI-2 on the PSSCH. More specifically, the anchor UE 600 may send the SCI-2 on the PSSCH rate matched according to the rate matching rules, as described above with reference to the first and second rate matching rules (as examples). To this end, the anchor UE 600 may rate match the SCI-2 from the start 802 of the PSSCH and continue to rate match the SCI-2 to any available resource elements on the PSSCH to the end of the timeslot (for example). Alternatively, the anchor UE 600 may (with reference to the example in Fig.10 ) in the example shown in , in the second time period 1002, the first part 1001 of SCI-2 is rate matched from DMRS 406, returns to the first time period 1004, and in the first time period 1004, the second part 1008 of SCI-2 is rate matched from the first resource element after PSCCH.

[0128] Returning to decision block 1110, if instead the anchor UE 600 determines that the PSSCH includes user data, the process 1100 may instead proceed to block 1114. At block 1114, the anchor UE 600 may send SCI-2 on the PSSCH according to an additional rate matching rule. In some cases, rate matching the SCI-2 according to the additional rate matching rule may involve rate matching the SCI-2 from the beginning of the DMRS 406, such as in Fig.12 As shown in and discussed further below.

[0129] At block 1116, the anchor UE 600 may transmit the user data identified at block 1110 on the PSSCH. As described in more detail below, transmitting the user data may involve transmitting the user data during the first time period 1004 ( Fig.12 ) and the second time period 1002 ( Fig.12 ), wherein the SCI-2 data is included starting from DRMS ​​406 as Fig.12 SCI-2 1152.

[0130] Now go to Fig.12, provides an exemplary block diagram of a sidelink resource 1150. As shown, the sidelink resource 1150 includes user data 1154 and SCI-2 1152 (e.g., Fig.11 1114).

[0131] In some embodiments, the sidelink resource 1150 includes a first portion of the user data 1154 within the first time period 1004. To this end, refer to Fig.11 At block 1116 of the embodiment, the anchor UE 600 may send a first portion of the user data 1154 within the first time period 1004. In addition, the anchor UE 600 may send a second portion of the user data 1154 within the second time period 1002 such that the sidelink resource 1150 includes the user data 1154 within the second time period 1002.

[0132] In the case where user data 1154 is present in the second time period 1002 of the PSSCH, the SCI-2 1152 may be rate matched according to an additional rate matching rule to occupy a set of resource elements of the PSSCH that are not occupied and / or not reserved for user data 1154 in the second time period 1002 (e.g., at the beginning of the DMRS 406). Accordingly, the SCI-2 1152 may be rate matched to a subset of resource elements after the DMRS 406, such as Fig.12 shown.

[0133] Accordingly, as shown and discussed above, with assistance from SCI-1 (e.g., indicating whether user data is present in a time slot), a reverse link grant may be sent as a block to multiple client UEs 500 as part of SCI-2. In other embodiments, the anchor UE 600 may be configured to send a reverse link grant using a third stage control information (SCI-3). In such an embodiment, SCI-1 may include information associated with SCI-2 (e.g., without any changes, such as additional or modified data fields), SCI-2 may include data associated with SCI-3 (e.g., including new information, such as in one or more new data fields regarding a new SCI-3), and SCI-3 may include a reverse link grant, as described in more detail below.

[0134] Fig.131 is a flow chart of a third reverse link grant transmission process 1300 utilizing SCI-3 in accordance with aspects of the present disclosure. Aspects of process 1300 may be performed by a computing device (e.g., a processor, processing circuitry, and / or other appropriate components) of a wireless communication device or other appropriate means for performing such steps. For example, a wireless communication device (such as UE 115, 215, and / or 600) may utilize one or more components (such as processor 602, memory 604, anchor sidelink communication module 608, transceiver 610, modem 612, and one or more antennas 616) to perform the steps of process 1300. Process 1300 may employ the same techniques as described above with respect to Figure 7 Similar mechanisms in the process 700 discussed. As shown, process 1300 includes a plurality of enumerated steps, but aspects of process 1300 may include additional steps before, after, and between the enumerated steps. In some aspects, one or more of the enumerated steps may be omitted or performed in a different order.

[0135] At block 1302, the anchor UE 600 may determine one or more reverse link grants for transmission. In some aspects, the anchor UE 600 may determine the reverse link grant based in part on the scheduling conditions at the anchor UE 600, as described above with reference to Figure 7 Furthermore, each reverse link grant may correspond to a particular client UE 500. Accordingly, the reverse link grant may be configured to provide scheduling information so that the anchor UE 600 may successfully receive the corresponding transmission from the client UE 500 to the anchor UE 600. Further, in some embodiments, the anchor UE 600 may aggregate one or more reverse link grants into a single block for transmission (e.g., according to Fig.13 An embodiment of the invention is given in SCI-3).

[0136] At block 1304, the anchor UE 600 may send SCI-1 on the PSSCH. In some aspects, the SCI-1 may include data associated with the SCI-2, such as the size of the SCI-2. Further, in some embodiments, the data fields included in the SCI-1 may remain unchanged compared to the data fields in the SCI-1 sent independently of the reverse link grant and / or SCI-3. That is, as described in more detail below, the data fields associated with the transmission of the SCI-3 and / or reverse link grant may be included in the SCI-2. For example, in some embodiments, regardless of whether the block of the reverse link grant is sent with the user data (e.g., forward link data), the SCI-1 may not require an additional flag to indicate the presence or absence of the user data on the PSSCH. In contrast, the anchor sidelink communication module 608 may configure the SCI-1 to treat the SCI-3 and the user data substantially equally. Accordingly, any information about the SCI-3 and / or any additional information about the user data may be captured in the SCI-2 instead.

[0137] At block 1306, the anchor UE 600 may transmit SCI-2 rate matched from the DMRS 406 on the PSSCH (see, e.g., Fig.14 , as discussed further below). In some aspects, DMRS 406 may be transmitted on the PSSCH after the first time period 1004. Accordingly, SCI-2 may be rate matched from DMRS 406 after the first time period 1004. Furthermore, in some embodiments, rate matching SCI-2 may involve overlapping SCI-2 with DMRS 406 such that a particular resource block may contain both a portion of DMRS 406 and a portion of SCI-2.

[0138] According to some aspects, as discussed above, SCI-2 may include a data field associated with SCI-3. More specifically, in some embodiments, SCI-2 may include a data field configured to indicate whether the PSSCH includes user data, a data field configured to indicate the presence of SCI-3 on the PSSCH, a data field configured to indicate the structure of the SCI-3 (such as the length (e.g., size) of the SCI-3), a data field configured to provide parsing instructions associated with the SCI-3, or a suitable combination thereof. SCI-2 may also indicate the number of client UEs 500 associated with the SCI-3 and / or the number of reverse link grants included in the SCI-3. Further, in some embodiments, the SCI-3 may have the same MCS level and / or the same beta offset for resource allocation as the SCI-2. In such an embodiment, SCI-2 may omit a data field indicating the MCS level and / or beta offset of the SCI-3 and / or resource allocation, because the anchor UE 600 and / or the client UE 500 may be preconfigured to use the MCS level and / or beta offset of the SCI-2, and use the MCS level and / or beta offset of the SCI-3 by association. In an embodiment where the MCS level and / or beta offset of the SCI-3 is different from the MCS level and / or beta offset of the SCI-2, the SCI-2 may include one or more data fields configured to indicate the MCS level and / or beta offset of the SCI-3, respectively.

[0139] At decision block 1308, the anchor UE 600 may determine whether the PSSCH includes user data (e.g., the anchor UE 600 may determine whether it has any user data to be sent via the forward link in the PSSCH in the time slot). If it is determined at decision block 1308 that there is no user data to be sent in the forward link with the SCI-3, the process 1300 proceeds to block 1310.

[0140] At block 1310, the anchor UE 600 may send SCI-3 on the PSSCH rate-matched from the first resource element at the start 802 of the PSSCH. For example, the SCI-3 may be rate-matched such that the SCI-3 occupies any available and / or unreserved resource element on the PSSCH after the start 802 of the PSSCH. Accordingly, in some embodiments, for example, with reference to Fig.14 , a first portion of SCI-3 may be rate matched within a first time period 1004 prior to the DMRS 406 signal, and rate matching of SCI-3 may continue using a second portion of SCI-3 that is rate matched from SCI-2 and / or DMRS 406, such as until the end of the timeslot.

[0141] Returning to decision block 1308, if it is determined that there is user data to be sent with the SCI-3 in the forward link, the process 1300 proceeds to block 1312. At block 1312, the anchor UE 600 may send the SCI-3 and the user data on the PSSCH 320. For example, the SCI-3 may be rate matched so that the SCI-3 occupies any available and / or unreserved resource elements on the PSSCH after the start 802 of the PSSCH. Accordingly, in some embodiments, for example, with reference to Fig.15 , the first portion of SCI-3 may be rate matched within the first time period 1004 before the DMRS406 signal. If there is more information of SCI-3 that is not adapted within the first time period 1004, the rate matching of SCI-3 may continue using the second portion of SCI-3, which is rate matched from SCI-2 and / or DMRS 406, but not rate matched to the end of the timeslot. Conversely, user data may follow the end of SCI-3, immediately after DMRS 406 and SCI-2, or immediately after the last portion of SCI-3 included after DMRS 406 / SCI-2. For example, the anchor UE 600 may send user data after the first time period 1004 because resource elements of the PSSCH within the first time period 1004 may be occupied and / or reserved for SCI-3. To this end, in some embodiments, such as Fig.15 As shown, the anchor UE 600 may transmit user data on the PSSCH after SCI-3.

[0142] Now go to Fig.14 , an exemplary sidelink resource 1400 having one or more reverse link grants is provided. As shown, the sidelink resource 1400 includes SCI-1 on the PSCCH 804 and SCI-2 1402 and SCI-3 1404 on the PSSCH. The sidelink resource 1400 also shows SCI-2 1402 being rate matched from the start of DMRS 406, as described above with reference to block 1206. In the illustrated embodiment, SCI-2 1401 and DMRS 406 overlap in time. As further shown, SCI-3 1404 is rate matched from the start 802 of the PSSCH until the start of DMRS 406, and continues from SCI-2 1402 in a second time period 1002. Due to the Fig.14In the example of , user data is not included on the PSSCH, so the transmission of the sidelink resources 1400 can be dedicated to information associated with the reverse link grant included in SCI-3 (which is rate matched on the entire available PSSCH). To this end, the anchor UE 600 can send each portion of the sidelink resources 1400 (e.g., SCI-1, SCI-2, DMRS, SCI-3, etc.) regardless of whether the forward link transmission occurs on the sidelink (e.g., 251, 252, 254, 256) and / or is directed to a specific client UE 500.

[0143] Fig.15 An exemplary block diagram of sidelink resources 1500 with one or more reverse link grants is shown. In the illustrated embodiment, the sidelink resources 1500 include SCI-1 on PSCCH 804 and SCI-2 1502, SCI-3 1504, and user data 1506 on PSSCH. Fig.14 As described with reference to sidelink resource 1400, sidelink resource 1500 shows SCI-2 1502 being rate matched from the start of DMRS 406. In addition, SCI-3 1506 is rate matched from the start 802 of PSSCH, and the rate matching of SCI-3 1506 continues from the end of SCI-2 1502 in the second time period 1002. In the second time period 1002, SCI-3 1504 is rate matched to accommodate user data. Fig.14 Compared to the sidelink resources 1400, the SCI-3 1506 is rate matched to fewer resource elements (not across the entire available PSSCH), so that the anchor UE 600 can use the remaining resource elements to send user data 1506 on the PSSCH.

[0144] As described above, in some embodiments, the anchor UE 600 may treat the SCI-3 1504 as user data from the perspective of control information. That is, for example, regardless of whether the anchor UE 600 transmits the SCI-3 1506 together with the user data 1506, the SCI-1 on the PSCCH 804 may remain unchanged, because the SCI-3 1504 may be transmitted in resource elements that may also be occupied by user data of the PSSCH. Fig.15 As shown, the anchor UE 600 may transmit SCI-3 1504 as first user data on the PSSCH, and may transmit user data 1506 as second user data. More specifically, in some embodiments, the anchor UE 600 may transmit the user data after SCI-3.

[0145] Although the above describes the embodiment with reference to the DMRS 406 transmitted after the first time period 1004, Figure 13-15 , but in some embodiments, the anchor UE 600 may send the DMRS 406 at the start 802 of the PSSCH (e.g., within or before the first time period 1004). In such an embodiment, the anchor UE 600 may rate match the SCI-2 1502 from the start of the DMRS 406. The anchor UE 600 may also rate match the SCI-3 1504 from the SCI-2 1502. In such an embodiment, the anchor UE 600 may rate match the SCI-3 1504 to occupy the remaining resource elements of the PSSCH (if there is no user data 1506) or to occupy a subset of the remaining resource elements of the PSSCH to accommodate the user data 1506.

[0146] Information and signals may be represented using any of a variety of different techniques and methods. For example, data, instructions, commands, information, signals, bits, symbols, and chips mentioned throughout the above description may be represented by voltage, current, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0147] The various illustrative blocks and modules described in conjunction with the disclosure herein may be implemented or executed using a general purpose processor, DSP, ASIC, 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. A general purpose processor may be a microprocessor, but in an alternative, the processor may be any conventional 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, a plurality of microprocessors, a combination of one or more microprocessors and a DSP core, or any other such configuration).

[0148] The functions described herein can be implemented in hardware, software executed by a processor, firmware, or any combination thereof. When implemented in software executed by a processor, the functions can be stored on a computer-readable medium as one or more instructions or codes or sent by it. Other examples and implementations are within the scope of protection of the present disclosure and the appended claims. For example, due to the nature of software, the functions described above can be implemented using software, hardware, firmware, hard wiring, or any combination thereof executed by a processor. The features used to implement the functions can be physically located at multiple locations, including being distributed so that the parts of the functions are implemented at different physical locations. In addition, as used herein (including in the claims), "or" (for example, "or" used in a list of items ending with "at least one of" or "one or more of") indicates an inclusive list, so that, for example, a list of [at least one of 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).

[0149] As will be understood by those skilled in the art by now, and depending on the specific application at the time, many modifications, substitutions and changes may be made in and to the materials, devices, configurations and methods of use of the devices of the present disclosure without departing from the spirit and scope of the present disclosure. In view of this, the scope of the present disclosure should not be limited to the scope of the specific embodiments shown and described herein (as they are only by way of some examples thereof), but should be fully commensurate with the claims appended hereto and their functional equivalents.

Claims

1. A method of wireless communication, comprising: determining, by a first user equipment (UE), a plurality of reverse link grants for corresponding plurality of UEs to transmit sidelink data to the first UE; The first UE sends first sidelink control information on a physical sidelink control channel (PSCCH); as well as A demodulation reference signal (DMRS) and second sidelink control information are sent by the first UE on a physical sidelink shared channel (PSSCH), and the second sidelink control information includes in a block the multiple reverse link grants for the corresponding multiple UEs to send the sidelink data to the first UE.

2. The method according to claim 1, wherein: Sending the DMRS includes: sending the DMRS on the PSSCH after a first time period.

3. The method according to claim 2, wherein: Sending the second sidelink control information includes: Starting before the start of the DMRS, the second sidelink control information is rate matched from a first resource element after the PSCCH at the start of the first time period.

4. The method according to claim 2, wherein: Sending the second sidelink control information includes: In a second time period after the first time period, rate matching a first part of the second sidelink control information from the beginning of the DMRS; Returning to the beginning of the first time period; and A second portion of the second sidelink control information is rate matched from a first resource element after the PSCCH at the beginning of the first time period until the DMRS.

5. The method according to claim 4, wherein: Sending the second sidelink control information includes: transmitting the second portion of the second sidelink control information during the first time period; and The first portion of the second sidelink control information is transmitted during the second time period.

6. The method according to claim 2, further comprising: sending, by the first UE, user data on the PSSCH during the first time period; as well as In a second time period after the first time period, rate matching is performed on the second sidelink control information from the beginning of the DMRS.

7. The method according to claim 1, wherein: Sending the DMRS includes: sending the DMRS at the beginning of a first symbol on the PSSCH; and Sending the second sidelink control information includes: performing rate matching on the second sidelink control information from the beginning of the DMRS.

8. The method of claim 1, further comprising at least one of the following: A first rate matching rule is selected by the first UE in response to the PSSCH not including user data, wherein: The first rate matching rule comprises: performing rate matching on a portion of the second sidelink control information in a first time period at the beginning of the PSSCH and before the start of the DMRS; or A second rate matching rule is selected by the first UE in response to the PSSCH including user data, wherein the user data starts before the DMRS at the beginning of the PSSCH, and the second rate matching rule includes rate matching starting from the beginning of the DMRS.

9. The method according to claim 1, wherein: The second sidelink control information further includes at least one of the following: a respective reverse link grant identifier corresponding to each reverse link grant of the plurality of reverse link grants; a respective user identifier corresponding to each of the plurality of UEs; or An indication of the number of reverse link grants included in the block.

10. A method of wireless communication, comprising: Determining, by a first user equipment (UE), a plurality of reverse link grants for a plurality of UEs to transmit sidelink data to the first UE; Sending, by the first UE, first sidelink control information on a physical sidelink control channel (PSCCH); and The first UE sends the following on a physical sidelink shared channel (PSSCH): Demodulation Reference Signal (DMRS); second sidelink control information configured to provide information related to the third sidelink control information; as well as The third sidelink control information includes, in a block, the multiple reverse link grants for the multiple UEs to send the sidelink data to the first UE.

11. The method according to claim 10, wherein: Sending the DMRS includes: sending the DMRS on the PSSCH after a first time period.

12. The method according to claim 10, further comprising: In response to the PSSCH not including user data: performing rate matching on the second sidelink control information from the beginning of the DMRS; as well as Starting before the DMRS and the second sidelink control information and continuing after the DMRS and the second sidelink control information, the third sidelink control information is rate matched from a first resource element at the beginning of the PSSCH.

13. The method according to claim 12, wherein: The second sidelink control information includes: a length of the third sidelink control information, and information indicating how to parse the block in the third sidelink control information.

14. The method according to claim 10, further comprising: In response to the PSSCH including user data: performing rate matching on the second sidelink control information from the beginning of the DMRS; Starting before the DMRS and the second sidelink control information, rate matching the third sidelink control information from a first resource element at the beginning of the PSSCH; and The user data is included after the DMRS.

15. The method according to claim 14, further comprising: The rate matching of the third sidelink control information is continued after the DMRS and the second sidelink control information and before the user data on the PSSCH.

16. The method according to claim 10, wherein: The second sidelink control information includes at least one of the following: an indication of a beta offset for said third sidelink control information; The block size of the third sidelink control information; or The number of the multiple UEs.

17. The method according to claim 10, wherein: The transmitting on the PSSCH further comprises: Sending the DMRS as a first symbol on the PSSCH; performing rate matching on the second sidelink control information from the beginning of the DMRS; and The third sidelink control information is rate matched from the end of the second sidelink control information.

18. The method according to claim 10, wherein: The third sidelink control information also includes a UE identifier for each of the plurality of UEs corresponding to each of the respective reverse link grants.

19. A user equipment (UE), comprising: means for determining a plurality of reverse link grants for a corresponding plurality of UEs to transmit sidelink data to the user equipment; means for transmitting first sidelink control information on a physical sidelink control channel (PSCCH); as well as A unit for sending a demodulation reference signal (DMRS) and second sidelink control information on a physical sidelink shared channel (PSSCH), wherein the second sidelink control information includes in a block the multiple reverse link grants for the corresponding multiple UEs to send the sidelink data to the user equipment.

20. The user equipment according to claim 19, wherein: The means for sending the DMRS includes: a means for sending the DMRS on the PSSCH after a first time period.

21. The user equipment according to claim 20, wherein: The unit for sending the second sidelink control information includes: Means for rate matching the second sidelink control information from a first resource element after the PSCCH at the start of the first time period, starting before the start of the DMRS.

22. The user equipment according to claim 20, wherein: The unit for sending the second sidelink control information includes: means for rate matching a first portion of the second sidelink control information from the beginning of the DMRS in a second time period after the first time period; means for returning to the start of said first time period; and A unit for rate matching a second portion of the second sidelink control information from a first resource element after the PSCCH at the beginning of the first time period to the DMRS.

23. The user equipment according to claim 22, wherein: The unit for sending the second sidelink control information includes: means for transmitting said second portion of said second sidelink control information during said first time period; and Means for transmitting the first portion of the second sidelink control information during the second time period.

24. The user equipment according to claim 20, further comprising: means for sending, by the user equipment, user data on the PSSCH during the first time period; as well as A unit for performing rate matching on the second sidelink control information from the beginning of the DMRS in a second time period after the first time period.

25. The user equipment according to claim 19, wherein: The means for transmitting the DMRS includes: a means for transmitting the DMRS at the beginning of a first symbol on the PSSCH; and The means for transmitting the second sidelink control information includes means for rate matching the second sidelink control information from the beginning of the DMRS.

26. The user equipment of claim 19, further comprising at least one of the following: means for selecting, by the user equipment, a first rate matching rule in response to the PSSCH not including user data, wherein The first rate matching rule comprises: performing rate matching on a portion of the second sidelink control information in a first time period at the beginning of the PSSCH and before the start of the DMRS; or Means for selecting, by the user equipment, a second rate matching rule in response to the PSSCH comprising user data, wherein the user data begins at the beginning of the PSSCH before the DMRS, and the second rate matching rule comprises rate matching starting from the beginning of the DMRS.

27. The user equipment according to claim 19, wherein: The second sidelink control information further includes at least one of the following: a respective reverse link grant identifier corresponding to each reverse link grant of the plurality of reverse link grants; a respective user identifier corresponding to each of the plurality of UEs; or An indication of the number of reverse link grants included in the block.

28. The user equipment according to claim 19, further comprising: Means for identifying, by the user equipment, a size of the second sidelink control information in the first sidelink control information.

29. A user equipment (UE), comprising: means for determining a plurality of reverse link grants for a plurality of UEs to transmit sidelink data to the user equipment; means for transmitting first sidelink control information on a physical sidelink control channel (PSCCH); and Means for transmitting on a physical sidelink shared channel (PSSCH): Demodulation Reference Signal (DMRS); second sidelink control information configured to provide information related to the third sidelink control information; as well as The third sidelink control information includes, in a block, the plurality of reverse link grants for the plurality of UEs to send the sidelink data to the user equipment.

30. The user equipment according to claim 29, wherein: The means for sending the DMRS includes: a means for sending the DMRS on the PSSCH after a first time period.

31. The user equipment according to claim 29, further comprising: means for rate matching the second sidelink control information from the beginning of the DMRS in response to the PSSCH not including user data; as well as means for rate matching the third sidelink control information from a first resource element at the beginning of the PSSCH, starting before the DMRS and the second sidelink control information and continuing after the DMRS and the second sidelink control information.

32. The user equipment according to claim 31, wherein: The second sidelink control information includes: a length of the third sidelink control information, and information indicating how to parse the block in the third sidelink control information.

33. The user equipment according to claim 29, further comprising: means for rate matching the second sidelink control information from the beginning of the DMRS in response to the PSSCH including user data; means for rate matching the third sidelink control information starting from a first resource element at the beginning of the PSSCH before the DMRS and the second sidelink control information; as well as A unit for including the user data after the DMRS.

34. The user equipment according to claim 33, further comprising: and a unit for continuing the rate matching of the third sidelink control information after the DMRS and the second sidelink control information and before the user data on the PSSCH.

35. The user equipment according to claim 29, wherein: The unit for transmitting on the PSSCH also includes: a unit for transmitting the DMRS as a first symbol on the PSSCH; means for rate matching the second sidelink control information from the beginning of the DMRS; and means for rate matching the third sidelink control information from an end of the second sidelink control information.

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