Discovery signal transmission for sidelink communication on unlicensed bands

Abstract

Wireless communication systems and methods related to discovery signaling for lateral link communication are provided. In one aspect, a first user equipment (UE) transmits synchronization communication to a second UE in a first time slot and a first portion of a subband of a shared frequency band, wherein the synchronization communication indicates the location of a discovery signal in a second portion of the subband of the shared frequency band. The first UE also transmits the discovery signal to the second UE in the first time slot and in the second portion of the subband of the shared frequency band.

Description

[0001] Cross-references to related applications

[0002] This application claims priority and benefit to U.S. Patent Application No. 17 / 305,314, filed July 2, 2021, the entire contents of which are incorporated herein by reference as fully set forth below and for all applicable purposes. Technical Field

[0003] This application relates to wireless communication systems, and more specifically, to transmitting discovery signals for sidelink communication in a shared radio frequency band (e.g., in shared spectrum or unlicensed spectrum) utilized by multiple network operating entities. Background Technology

[0004] Wireless communication systems are widely deployed to provide various types of communication content, such as voice, video, packet data, messaging, and broadcasting. These systems can support communication with multiple users by sharing available system resources (e.g., time, frequency, and power). Wireless multiple access communication systems may include multiple base stations (BSs), each supporting communication with multiple communication devices (which may also be referred to as user equipment (UE)) simultaneously.

[0005] To meet the growing demand for extended mobile broadband connectivity, wireless communication technologies are evolving from Long Term Evolution (LTE) to Next Generation New Radio (NR) technologies (which can be referred to as 5G). For example, compared to LTE, NR is designed to provide lower latency, higher bandwidth or higher throughput, and higher reliability. NR is designed to operate across a wide variety of spectrum bands, from low-frequency bands below approximately 1 GHz and mid-frequency bands from approximately 1 GHz to approximately 6 GHz, to high-frequency bands such as millimeter wave (mm wave) bands. NR is also designed to operate across different spectrum types, from licensed spectrum to unlicensed spectrum and shared spectrum. Spectrum sharing allows operators to opportunistically aggregate spectrum to dynamically support high-bandwidth services. Spectrum sharing can extend the benefits of NR technology to operating entities that may not have access to licensed spectrum.

[0006] In wireless communication networks, a BS can communicate with a UE in both the uplink and downlink directions. LTE introduced sidelinks to allow a UE to send data to another UE without tunneling through the BS and / or the associated core network. LTE sidelink technology has been extended to provide device-to-device (D2D) communication, vehicle-to-everything (V2X) communication, and / or cellular vehicle-to-everything (C-V2X) communication. Similarly, NR can be extended to support sidelink communication for D2D, V2X, and / or C-V2X on dedicated, licensed, and / or unlicensed spectrum. Summary of the Invention

[0007] The following outlines some aspects of this disclosure to provide a basic understanding of the techniques discussed. This overview is not a general summary of all anticipated features of this disclosure, nor is it intended to identify key or essential elements of all aspects of this disclosure, nor to describe the scope of any or all aspects of this disclosure. Its sole purpose is to present some concepts of one or more aspects of this disclosure in an overview form as a prelude to the more detailed description that follows.

[0008] One aspect of this disclosure includes a method performed by a first user equipment (UE). The method includes: transmitting a synchronization communication to a second UE in a first time slot and a first portion of a sub-band of a shared frequency band, wherein the synchronization communication indicates the location of a discovery signal in a second portion of the sub-band of the shared frequency band; and transmitting the discovery signal to the second UE in the first time slot and in the second portion of the sub-band of the shared frequency band.

[0009] One aspect of this disclosure includes a method performed by a first user equipment (UE). The method includes: receiving synchronization communication from a second UE in a first time slot and a first portion of a sub-band of a shared frequency band, wherein the synchronization communication indicates the location of a discovery signal in a second portion of the sub-band of the shared frequency band; and receiving the discovery signal from the second UE in the first time slot and in the second portion of the sub-band of the shared frequency band based on the synchronization communication.

[0010] One aspect of this disclosure includes a first user equipment (UE). The first user equipment includes: a transceiver; and a processor communicating with the transceiver. The processor is configured to cause the transceiver to: transmit a synchronization communication to a second UE in a first time slot and a first portion of a subband of a shared frequency band, wherein the synchronization communication indicates the location of a discovery signal in a second portion of the subband of the shared frequency band; and transmit the discovery signal to the second UE in the first time slot and in the second portion of the subband of the shared frequency band.

[0011] One aspect of this disclosure includes a first user equipment (UE). The first user equipment includes: a transceiver; and a processor communicating with the transceiver. The processor is configured to cause the transceiver to: receive synchronization communication from a second UE in a first time slot and a first portion of a subband of a shared frequency band, wherein the synchronization communication indicates the location of a discovery signal in a second portion of the subband of the shared frequency band; and receive the discovery signal from the second UE in the first time slot and in the second portion of the subband of the shared frequency band based on the synchronization communication.

[0012] Other aspects, features, and embodiments of the invention will become apparent to those skilled in the art when viewed in conjunction with the accompanying drawings of specific, exemplary embodiments thereof. While features of the invention may be discussed with respect to certain embodiments and figures below, all embodiments of the invention may include one or more of the advantageous features discussed herein. In other words, although one or more embodiments may be discussed as features with certain advantages, one or more such features may also be used according to the various embodiments of the invention discussed herein. Similarly, while exemplary embodiments may be discussed below as devices, systems, or methods, it should be understood that such exemplary embodiments may be implemented in various devices, systems, and methods. Attached Figure Description

[0013] Figure 1 A wireless communication network according to some aspects of this disclosure is shown.

[0014] Figure 2 A wireless communication network providing side link communication according to some aspects of this disclosure is shown.

[0015] Figure 3 A sidelink communication scheme based on some aspects of this disclosure is shown.

[0016] Figure 4 A detection signal transmission scheme in a side-link communication scenario is illustrated, based on some aspects of this disclosure.

[0017] Figure 5 This is a simplified block diagram of an exemplary frame structure of a sidelink master information block according to some aspects of this disclosure.

[0018] Figure 6 This is a signaling diagram of a method for discovering signaling in a sidelink communication scenario, based on some aspects of this disclosure.

[0019] Figure 7This is a block diagram of an exemplary user equipment (UE) based on some aspects of this disclosure.

[0020] Figure 8 This is a flowchart of a discovery signal transmission scheme in a sidelink communication scenario based on some aspects of this disclosure.

[0021] Figure 9 This is a flowchart of a detection signal reception scheme in a sidelink communication scenario based on some aspects of this disclosure. Detailed Implementation

[0022] The specific embodiments described below with reference to the accompanying drawings are intended as a description of various configurations, and not as representing only the configurations in which the concepts described herein can be practiced. Specific details are included in the specific embodiments for the purpose of providing a thorough understanding of the various concepts. However, it will be apparent to those skilled in the art that these concepts can be practiced without these specific details. In some cases, well-known structures and components are shown in block diagram form to avoid obscuring such concepts.

[0023] In summary, this disclosure relates to wireless communication systems, also known as wireless communication networks. In various embodiments, the techniques and apparatus described can be used in 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, and 5G or New Radio (NR) networks. As described herein, the terms "network" and "system" are used interchangeably.

[0024] OFDMA networks can implement radio technologies such as Evolved UTRA (E-UTRA), IEEE 802.11, IEEE 802.16, IEEE 802.20, and Flash-OFDM. UTRA, E-UTRA, and GSM are part of the 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 from an organization called the 3rd Generation Partnership Project (3GPP), and cdma2000 is described in documents from an organization called 3rd Generation Partnership Project 2 (3GPP2). These various radio technologies and standards are either known or under development. For example, the 3rd Generation Partnership Project (3GPP) is a collaboration between telecommunications association groups aimed at defining globally applicable third-generation (3G) mobile phone specifications. 3GPP Long Term Evolution (LTE) is a 3GPP initiative aimed at improving the UMTS mobile phone standard. 3GPP defines specifications for next-generation mobile networks, mobile systems, and mobile devices. This disclosure relates to the evolution of wireless technologies such as LTE, 4G, 5G, NR, and beyond, which features shared access to radio spectrum between networks using some new and different radio access technologies or radio air interfaces.

[0025] 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 the development of new radio technologies for 5G NR networks, further enhancements to LTE and LTE-A are also considered. 5G NR will be able to extend to: (1) providing coverage for massive Internet of Things (IoT), which has ultra-high density (e.g., ~1M nodes / km). 2 (1) Provide coverage with ultra-low complexity (e.g., ~10 s bits / second), ultra-low energy (e.g., ~10+ years of battery life), and deep coverage with the ability to reach challenging locations; (2) Provide coverage including mission-critical controls with strong security for protecting sensitive personal, financial, or confidential information, ultra-high reliability (e.g., ~99.9999% reliability), ultra-low latency (e.g., ~1 millisecond), and coverage for users with a wide range of mobility or lack of mobility; and (3) Provide coverage with enhanced mobile broadband, including extremely high capacity (e.g., ~10 Tbps / km). 2 ), extremely high data rates (e.g., multi-Gbps rates, 100+Mbps user experience rates), and deep awareness with improved discovery and optimization.

[0026] 5G NR can be implemented using optimized OFDM-based waveforms with scalable digital schemes (numerology) and transmission time intervals (TTI); a common, flexible architecture to efficiently multiplex services and features using dynamic, low-latency Time Division Duplex (TDD) / Frequency Division Duplex (FDD) designs; and improved radio technologies such as massive MIMO, robust millimeter-wave (mmWave) transmission, improved channel coding, and device-centric mobility. The scalability of the digital scheme in 5G NR (where scaling of subcarrier spacing) efficiently addresses the operation of diverse services across diverse spectrum and deployments. For example, in various outdoor and macro coverage deployments with FDD / TDD implementations below 3 GHz, subcarrier spacing can occur at 15 kHz over bandwidths (BWs) such as 5, 10, and 20 MHz. For other various outdoor and small cell coverage deployments with TDD above 3 GHz, subcarrier spacing can occur at 30 kHz over an 80 / 100 MHz BW. For various other indoor broadband implementations using TDD in the unlicensed portion of the 5 GHz band, subcarrier spacing can occur at 60 kHz over a 160 MHz BW. Finally, for various deployments utilizing the mm-wave component of TDD at 28 GHz, subcarrier spacing can occur at 120 kHz over a 500 MHz BW.

[0027] 5G NR's scalable digital schemes facilitate scalable TTIs for diverse 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 begin at symbol boundaries. 5G NR also anticipates self-contained, integrated subframe designs with UL / downlink scheduling information, data, and acknowledgments within the same subframe. These self-contained, integrated subframes support communication in unlicensed or contention-based shared spectrum and can be flexibly configured per cell to dynamically switch between UL and downlink to meet current service demands, enabling adaptive UL / downlink.

[0028] The following further describes various other aspects and features of this disclosure. It should be apparent that the teachings herein can be embodied in a wide variety of forms, and that any particular structure, function, or both disclosed herein are merely representative and not limiting. Based on the teachings herein, those skilled in the art will understand that the aspects disclosed herein can be implemented independently of any other aspects, and that two or more of these aspects can be combined in various ways. For example, an apparatus or a method can be practiced using any number of the aspects set forth herein. Furthermore, such an apparatus or a method can be practiced using structures, functions, or structures and functions other than or different from one or more of the aspects set forth herein. For example, a method can be implemented as part of a system, device, apparatus, and / or as instructions stored on a computer-readable medium for execution on a processor or computer. Additionally, an aspect may include at least one element of the claims.

[0029] Sidelink communication refers to communication between user equipment (UE) devices without tunneling through a base station (BS) and / or core network. Sidelink communication can be transmitted via the Physical Sidelink Control Channel (PSCCH) and the Physical Sidelink Shared Channel (PSSCH). The PSCCH and PSSCH are similar to the Physical Downlink Control Channel (PDCCH) and Physical Downlink Shared Channel (PDSCH) in downlink (DL) communication between the BS and UE. For example, the PSCCH may carry sidelink control information (SCI), and the PSSCH may carry sidelink data (e.g., user data). Each PSCCH is associated with a corresponding PSSCH, where the SCI in the PSCCH may carry reservation and / or scheduling information for sidelink data transmission in the associated PSSCH. Use cases for sidelink communication can include V2X, enhanced mobile broadband (eMBB), industrial Internet of Things (IIoT), and / or NR-lite.

[0030] 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 independently of any tunnel through a BS (e.g., gNB) and / or associated core network. As used herein, the term "sidelink transmitting UE" may refer to a user equipment device that performs a sidelink transmitting operation. As used herein, the term "sidelink 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" refer to a sidelink UE designated as an anchor node with an independent sidelink configuration, which can initiate sidelink operations autonomously (e.g., independently of any cell and / or associated core network), and these terms are interchangeable without departing from the scope of this disclosure.

[0031] The deployment of NR in unlicensed spectrum is referred to as NR Unlicensed (NR-U). Some research has been conducted on NR-U deployment in the 5 GHz unlicensed band. The Federal Communications Commission (FCC) and the European Telecommunications Standards Institute (ETSI) are regulating 6 GHz as a new unlicensed band for wireless communications. Adding the 6 GHz band allows hundreds of megahertz (MHz) of bandwidth (BW) to be available for unlicensed band communications. Alternatively, NR-U can also be deployed in the 2.4 GHz unlicensed band, which is currently shared by various Radio Access Technologies (RATs) such as IEEE 802.11 Wireless LAN (WLAN) or WiFi and / or Licensed Assisted Access (LAA) (i.e., Wi-Fi). Sidelinks can benefit from utilizing the additional bandwidth available in the unlicensed spectrum. However, channel access in a particular unlicensed spectrum can be regulated by an authority. For example, the specifications in the 2.4 GHz band allow nodes to transmit without performing LBT when a node applies frequency hopping to a transmission and meets the requirements of a transmission sequence or on / off mode with a maximum transmission duration of approximately 5 ms and a minimum silence or gap duration of approximately 5 ms between transmissions.

[0032] For sidelinks on licensed spectrum, NR supports two Radio Resource Allocation (RRA) modes: Mode 1 RRA and Mode 2 RRA. Mode 1 RRA supports network-controlled RRA that can be used for sidelink communication within coverage. For example, the serving BS (e.g., gNB) can determine radio resources on behalf of the sidelink UE and send instructions for those resources to the sidelink UE. In some aspects, the serving BS utilizes downlink control information (DCI) to grant sidelink transmissions. However, significant base station involvement is present in this mode, and it is only operational if the sidelink UE is within the service BS's coverage area. Mode 2 RRA supports autonomous RRA that can be used for sidelink UEs outside coverage or partially covered sidelink UEs. For example, a sidelink UE outside coverage or partially covered UE can be pre-configured with a sidelink resource pool and can select radio resources for sidelink communication from this pre-configured pool. In this mode, V2X systems, CV2X systems, or other sidelink communication systems may operate independently of the serving BS. However, Mode-2 RRA relies on sidelink settings across different UEs and / or environments. Therefore, for Mode-2 RRA, sidelink settings can be coordinated to allow each sidelink UE to communicate with each other. Consequently, UE vendors (e.g., different automotive manufacturers or other UE manufacturers) may need to coordinate and implement common sidelink settings. This can place a significant burden on UE vendors to develop and implement a unified sidelink setting that allows all NR-U sidelink UE devices to communicate via corresponding sidelink connections. Therefore, this disclosure describes methods, apparatus, and systems for facilitating the deployment of NR-U sidelink systems as independent systems.

[0033] For example, this application describes a mechanism for transmitting and receiving discovery signals in a sidelink communication scenario. The mechanism described in this application allows the transmission and reception of discovery signals integrated with synchronization signals, such as synchronization signal blocks (SSBs). Specifically, a first sidelink UE can transmit a discovery signal to a second sidelink UE, the discovery signal being time-aligned with the SSB and occupying multiple RBs in a subband contiguous with the resource blocks (RBs) used to transmit the synchronization signal. Furthermore, the first sidelink UE can transmit the discovery signal such that it is quasi-co-located (QCL) with the synchronization signal. The discovery signal may include configuration information associated with the sidelink communication scheme between the UEs, such as resource pool configuration, UE identifier, UE network service information, and / or any other suitable sidelink configuration information. In some aspects, the structure of the discovery signal may be similar to or identical to the structure of the Residual Minimal System Information (RMSI).

[0034] This disclosure offers several benefits. For example, because the mechanism described herein uses time / frequency resources (e.g., RBs) associated with the configured synchronization signal, the discovery signal indication scheme advantageously allows for the transmission and reception of sidelink discovery information, enabling UEs from various manufacturers and / or operators to receive discovery information without additional cooperation or protocols for specific discovery signal settings and transmission structures. Furthermore, transmitting the discovery signal in a previously unused portion of the subband in which the synchronization signal is transmitted efficiently utilizes network resources, increases throughput, reduces UE power consumption, and increases user satisfaction with the wireless network. Additionally, control information and / or parameters for decoding and using the discovery information can be indicated in system information carried by the synchronization signal (such as the Master Information Block (MIB) carried in the Physical Broadcast Channel (PBCH) of the SSB). In this way, more RBs in the subband not designated for synchronization communication can be used to transmit the discovery signal, further improving the efficiency of sidelink communication, increasing throughput, reducing power consumption, and increasing user satisfaction with the wireless network.

[0035] Figure 1 A wireless communication network 100 is illustrated according to some aspects of this disclosure. Network 100 may be a 5G network. Network 100 includes multiple base stations (BSs) 105 (labeled 105a, 105b, 105c, 105d, 105e, and 105f, respectively) and other network entities. BS 105 may be a station communicating with UE 115, and may also be referred to as an evolved Node B (eNB), a next-generation eNB (gNB), an access point, etc. Each BS 105 may provide communication coverage for a specific geographic area. In 3GPP, the term "cell" may refer to that specific geographic coverage area of ​​BS 105 and / or the BS subsystem serving that coverage area, depending on the context in which the term is used.

[0036] BS 105 can provide communication coverage for macrocells or small cells (such as picocells or femtocells) and / or other types of cells. Macrocells typically cover a relatively large geographic area (e.g., a radius of several kilometers) and allow unrestricted access by UEs with service subscriptions to network providers. Small cells (such as picocells) will typically cover a relatively small geographic area and allow unrestricted access by UEs with service subscriptions to network providers. Small cells (such as femtocells) will also typically cover a relatively small geographic area (e.g., residential areas) and, in addition to unrestricted access, provide restricted access by UEs associated with that femtocell (e.g., UEs in a Closed Subscriber Group (CSG), UEs for users in a residence, etc.). A BS used for macrocells can be called a macro BS. A BS used for small cells can be called a small cell BS, pico BS, femtocell BS, or home BS. Figure 1 In the examples shown, BS 105d and 105e can be conventional macro BSs, while BS 105a-105c can be macro BSs implemented with one of three-dimensional (3D) MIMO, full-dimensional (FD) MIMO, or massive MIMO. BS 105a-105c can leverage their higher-dimensional MIMO capabilities to utilize 3D beamforming in both elevation and azimuth beamforming to increase coverage and capacity. BS 105f can be a small cell BS, which can be a home node or a portable access point. BS 105 can support one or more (e.g., two, three, four, etc.) cells.

[0037] Network 100 can support synchronous or asynchronous operation. For synchronous operation, BSs can have similar frame timing, and transmissions from different BSs can be approximately time-aligned. For asynchronous operation, BSs can have different frame timing, and transmissions from different BSs can be time-disaligned.

[0038] UE 115 is distributed throughout the wireless network 100, and each UE 115 can be stationary or mobile. UE 115 can also be referred to as a terminal, mobile station, user unit, station, etc. UE 115 can be a cellular phone, personal digital assistant (PDA), wireless modem, wireless communication device, handheld device, tablet computer, laptop computer, cordless phone, 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 115 can be a device without a UICC. In some aspects, UE 115 without a UICC can also be referred to as an IoT device or Internet of Things (IoE) device. UE 115a-115d are examples of mobile smartphone-type devices accessing the network 100. UE 115 can also be a machine specifically configured for connected communications (including Machine Type Communication (MTC), Enhanced MTC (eMTC), Narrowband IoT (NB-IoT), etc.). UE 115e-115h are examples of various machines configured for communication and accessing network 100. UE 115i-115k are examples of vehicles equipped with wireless communication devices configured for communication and accessing network 100. UE 115 can communicate with any type of BS (whether macro BS, small cell, etc.). Figure 1 In this context, a lightning bolt (e.g., a communication link) indicates a radio transmission between UE 115 and serving BS 105 (which is a BS designated to serve UE 115 on the downlink (DL) and / or uplink (UL), or a desired transmission between BS 105, a backhaul transmission between BSs, or a sidelink transmission between UE 115.

[0039] In operation, BS 105a-105c can use 3D beamforming and coordinated space technologies (e.g., Co-MP or multi-connectivity) to serve UE 115a and 115b. Macro BS 105d can perform backhaul communication with BS 105a-105c and the small cell BS 105f. Macro BS 105d can also transmit multicast services customized 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 Grey Alerts).

[0040] Base station 105 can also communicate with a core network. The core network can provide user authentication, access permission, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. At least some of the base stations in base station 105 (e.g., examples of gNBs or Access Node Controllers (ANCs)) can interface with the core network via backhaul links (e.g., NG-C, NG-U, etc.) and can perform radio configuration and scheduling for communication with UE 115. In various examples, BS 105 can communicate with each other directly or indirectly (e.g., via the core network) via backhaul links (e.g., X1, X2, etc.), which can be wired or wireless communication links.

[0041] Network 100 can also support mission-critical communication with highly reliable and redundant links for mission-critical devices (e.g., UE 115e, which could be a drone). Redundant communication links with UE 115e can 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)) can communicate directly with BSs (such as small cell BS 105f and macro BS 105e) via network 100, or via network 100 in a multi-step configuration by communicating with another user equipment that relays its information to the network. For example, UE 115f transmits temperature measurement information to smart meter UE 115g, and the temperature measurement information is subsequently reported to the network via small cell BS 105f. Network 100 can 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 UE 115, and / or vehicle-to-infrastructure (V2I) communications between UE 115i, 115j, or 115k and BS 105.

[0042] In some implementations, network 100 uses OFDM-based waveforms for communication. OFDM-based systems can divide the system BW into multiple (K) orthogonal subcarriers, which are also commonly referred to as subcarriers, tones, frequency bands, etc. Each subcarrier can be modulated using data. In some cases, the subcarrier spacing between adjacent subcarriers can be fixed, and the total number of subcarriers (K) can depend on the system BW. The system BW can also be divided into subbands. In other cases, the subcarrier spacing and / or the duration of the time interval (TTI) can be scalable.

[0043] In some aspects, BS 105 can assign or schedule transmission resources (e.g., in the form of time-frequency resource blocks (RBs)) 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. Communication can be in the form of radio frames. Radio frames can be divided into multiple subframes or time slots, for example, approximately 10. Each time slot can be further divided into micro-time slots. In FDD mode, simultaneous UL and DL transmissions can occur in different frequency bands. For example, each subframe includes UL subframes in the UL band and DL subframes in the DL band. In TDD mode, UL and DL transmissions using the same frequency band occur at different time periods. For example, a subset of subframes in a radio frame (e.g., DL subframes) can be used for DL ​​transmissions, while another subset of subframes in the same radio frame (e.g., UL subframes) can be used for UL transmissions.

[0044] DL subframes and UL subframes can be further divided into several regions. For example, each DL or UL subframe can have a predefined region for the transmission of reference signals, control information, and data. Reference signals are predetermined signals that facilitate communication between BS 105 and UE 115. For example, reference signals can have a specific pilot pattern or structure, where pilot tones can span the operating BW or frequency band, and each pilot tone is located at a predefined time and predefined frequency. For example, BS 105 can transmit cell-specific reference signals (CRS) and / or channel state information-reference signals (CSI-RS) to enable UE 115 to estimate the DL channel. Similarly, UE 115 can transmit sounding reference signals (SRS) to enable BS 105 to estimate the UL channel. Control information can include resource allocation and protocol control. Data can include protocol data and / or operational data. In some aspects, BS 105 and UE 115 can communicate using self-contained subframes. Self-contained subframes can include portions for DL ​​communication and portions for UL communication. A self-contained subframe can be DL-centric or UL-centric. A DL-centric subframe can include a longer duration for DL ​​communication (compared to the duration for UL communication). A UL-centric subframe can include a longer duration for UL communication (compared to the duration for UL communication).

[0045] In some aspects, network 100 may be an NR network deployed on licensed spectrum. BS 105 may transmit synchronization signals (e.g., including primary synchronization signal (PSS) and secondary synchronization signal (SSS)) in network 100 to facilitate synchronization. BS 105 may broadcast system information associated with network 100 (e.g., including primary information block (MIB), residual minimum system information (e.g., RMSI), and other system information (OSI)) to facilitate initial network access. In some cases, BS 105 may broadcast PSS, SSS, and / or MIB in the form of synchronization signal blocks (SSB) on the physical broadcast channel (PBCH), and may broadcast RMSI and / or OSI on the physical downlink shared channel (e.g., PDSCH).

[0046] In some respects, UE 115 attempting to access network 100 can perform an initial cell search by detecting the PSS from BS 105. The PSS can provide time-period timing synchronization and can indicate a physical layer identification value. UE 115 can then receive the SSS. The SSS can provide radio frame synchronization and can provide a cell identification value. The cell identification value can be combined with the physical layer identification value to identify the cell. The PSS and SSS can be located in the center portion of the carrier or at any suitable frequency within the carrier.

[0047] After receiving the PSS and SSS, UE 115 can receive the MIB. The MIB may include system information for initial network access and scheduling information for the RMSI and / or OSI. After decoding the MIB, UE 115 can receive the RMSI and / or OSI. The RMSI and / or OSI may include radio resource control (RRC) information related to the Random Access Channel (RACH) procedure, paging, control resource set (CORESET) for monitoring the Physical Downlink Control Channel (PDCCH), Physical UL Control Channel (PUCCH), Physical UL Shared Channel (PUSCH), power control, and SRS.

[0048] After obtaining the MIB, RMSI, and / or OSI, UE 115 can perform a random access procedure to establish a connection with BS 105. In some examples, the random access procedure can be a four-step random access procedure. For example, UE 115 can send a random access preamble, and BS 105 can respond using 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 grant, temporary cell radio network temporary identifier (C-RNTI), and / or backoff indicator. Upon receiving the random access response, UE 115 can send a connection request to BS 105, and BS 105 can respond using a connection response. The connection response may indicate a 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 can be a two-step random access procedure, where UE 115 can send the random access preamble and connection request in a single transmission, and BS 105 can respond by sending the random access response and connection response in a single transmission.

[0049] After the connection is established, UE 115 and BS 105 can enter the normal operation phase, during which they can exchange operational data. For example, BS 105 can schedule UE 115 to perform UL and / or DL ​​communication. BS 105 can send UL and / or DL ​​scheduling permission to UE 115 via PDCCH. The scheduling permission can be sent in the form of DL control information (DCI). BS 105 can send DL communication signals (e.g., carrying data) to UE 115 via PDSCH based on the DL scheduling permission. UE 115 can send UL communication signals to BS 105 via PUSCH and / or PUCCH based on the UL scheduling permission.

[0050] In some aspects, BS 105 can use HARQ technology to communicate with UE 115 to improve communication reliability, such as to provide URLLC services. BS 105 can schedule UE 115 for PDSCH communication by sending DL permission in the PDCCH. BS 105 can send DL data packets to UE 115 in the PDSCH according to the schedule. DL data packets can be sent in transport blocks (TBs). If UE 115 successfully receives DL data packets, UE 115 can send HARQ ACK to BS 105. Conversely, if UE 115 fails to successfully receive DL transmission, UE 115 can send HARQ NACK to BS 105. When receiving HARQ NACK from UE 115, BS 105 can retransmit DL data packets to UE 115. The retransmission may include the same encoded version of the DL data as the initial transmission. Alternatively, the retransmission may include a different encoded version of the DL data than the initial transmission. UE 115 can apply soft combining to combine coded data received from the initial transmission and retransmissions for decoding. BS 105 and UE 115 can also use a mechanism essentially similar to DL HARQ to apply HARQ to UL communications.

[0051] In some aspects, network 100 can operate on a system BW or a component carrier (CC) BW. Network 100 can divide the system BW into multiple BWPs (e.g., portions). BS 105 can dynamically assign UE 115 to operate on a specific BWP (e.g., a specific portion of the system BW). The assigned BWP can be referred to as the active BWP. UE 115 can monitor the active BWP in response to signaling information from BS 105. BS 105 can schedule UE 115 to perform UL or DL ​​communication on the active BWP. In some aspects, BS 105 can assign a pair of BWPs within a CC to UE 115 for UL and DL communication. For example, the BWP pair may include one BWP for UL communication and one BWP for DL ​​communication.

[0052] In some aspects, network 100 can 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. To avoid collisions, BS 105 and UE 115 may employ a Listen-Before-Speak (LBT) procedure to monitor transmission opportunities (TXOPs) in the shared channel. TXOPs may also be referred to as Co-transmission opportunities (COTs). For example, a transmitting node (e.g., BS 105 or UE 115) may perform an LBT before transmitting in the channel. When the LBT succeeds, the transmitting node may continue transmitting. When the LBT fails, the transmitting node may avoid transmitting in the channel.

[0053] LBT can be based on energy detection (ED) or signal detection. For energy detection-based LBT, the LBT result is pass when the signal energy measured from the channel is below a threshold. Conversely, the LBT result is failure when the signal energy measured from the channel exceeds the threshold. For signal detection-based LBT, the LBT result is pass when no channel reservation signal (e.g., a pre-defined preamble signal) is detected in the channel. Additionally, LBT can employ various modes. LBT modes can be, for example, Category 4 (CAT4) LBT, Category 2 (CAT2) LBT, or Category 1 (CAT1) LBT. CAT1 LBT is referred to as the no-LBT mode, where LBT is not performed before transmission. CAT2 LBT refers to LBT without a random backoff period. For example, the transmitting node can determine the channel measurement within a time interval and determine channel availability based on a comparison of the channel measurement with an ED threshold. CAT4 LBT refers to LBT with random backoff and a variable contention window (CW). For example, the transmitting node can draw a random number and backoff for a duration within a certain time unit based on the drawn random number.

[0054] In some aspects, network 100 can support sidelink communication between UEs 115 on a shared radio frequency band (e.g., in shared spectrum or unlicensed spectrum). In some aspects, UEs 115 can communicate with each other on a 2.4 GHz unlicensed frequency band. Figure 2 As shown, unlicensed frequency bands can be shared by multiple network operating entities using various radio access technologies (RATs) such as NR-U, WiFi, and / or Licensed Assisted Access (LAA).

[0055] In some aspects, network 100 can support independent sidelink communication between UEs 115 on a shared radio frequency band, wherein a subset of UEs 115 is adapted as anchor nodes (e.g., sidelink anchor UEs) and autonomously initiates sidelink operations for UEs 115. In this respect, the sidelink anchor UE is autonomous and can perform sidelink operations independently of any cell (such as BS105).

[0056] Figure 2 An example of a wireless communication network 200 providing side-link communication according to an embodiment of this disclosure is shown. Network 200 may correspond to a portion of network 100. For the sake of simplicity, Figure 2 Two BS205s (shown as 205a and 205b) and six UEs 215s (shown as 215a1, 215a2, 215a3, 215a4, 215b1, and 215b2) are illustrated, but it will be appreciated that embodiments of this disclosure can be extended to any suitable number of UEs 215s (e.g., approximately 2, 3, 4, 5, 7, or more) and / or BS205s (e.g., approximately 1, 3, or more). BS205s and UEs 215s can be similar to BS 105 and UE 115, respectively. BS205s and UEs 215s can share the same radio frequency band for communication. In some cases, the radio frequency band can be a 2.4 GHz unlicensed band, a 5 GHz unlicensed band, or a 6 GHz unlicensed band. Typically, the shared radio frequency band can be at any suitable frequency.

[0057] BS 205a and UE 215a1-215a4 can be operated by a first network operating entity. BS205b and UE 215b1-215b2 can be operated by a second network operating entity. In some aspects, the first network operating entity can utilize the same RAT as the second network operating entity. For example, BS205a and UE 215a1-215a4 of the first network operating entity and BS205b and UE 215b1-215b2 of the second network operating entity are NR-U devices. In some other aspects, the first network operating entity can utilize a different RAT than the second network operating entity. For example, BS205a and UE 215a1-215a4 of the first network operating entity can utilize NR-U technology, while BS205b and UE 215b1-215b2 of the second network operating entity can utilize WiFi or LAA technology.

[0058] In network 200, some of UEs 215a1-215a4 can communicate with each other in peer-to-peer communication. For example, UE 215a1 can communicate with UE 215a2 via side link 252, UE 215a3 can communicate with UE 215a4 via another side link 251, and UE 215b1 can communicate with UE 215b2 via yet another side link 254. Side links 251, 252, and 254 are unicast bidirectional links. Some UEs 215 can also communicate with BS205a or BS205b via communication link 253 in the UL direction and / or DL ​​direction. For example, UEs 215a1, 215a3, and 215a4 are within the coverage area 210 of BS205a and therefore can communicate with BS205a. UE 215a2 is outside the coverage area 210 and therefore can not communicate directly with BS205a. In some cases, UE 215a1 can operate as a relay for UE 215a2 to reach BS 205a. Similarly, UE 215b1 is within the coverage area 212 of BS 205b and can therefore communicate with BS 205b and can operate as a relay for UE 215b2 to reach BS 205b. In some aspects, some UE 215s are associated with a vehicle (e.g., similar to UE 115i-k), and communication on sidelinks 251, 252, and 254 can be C-V2X communication. C-V2X communication can refer to communication between the vehicle and any other wireless communication device in the cellular network.

[0059] As described above, NR supports an independent sidelink communication mechanism. In some aspects, the first user equipment (UE) includes: a processor configured to: determine system parameter information for initiating sidelink communication; and a transceiver configured to: transmit the system parameter information in one or more first subbands among a plurality of subbands within a shared radio frequency during a first time period; and, based on the system parameter information, transmit sidelink data with the second UE in a second subband among the plurality of subbands during a second time period different from the first time period.

[0060] For example, UE 215a2 can be used as a sidelink anchor UE, and UE 215a1 can be used as a sidelink receiving UE. UE 215a2 transmits system parameter information, including timing synchronization signals, via a sidelink broadcast channel (e.g., PSBCH), enabling UE 215a1 to receive and recover resource allocation and timing information to facilitate sidelink communication with UE 215a2. For purposes of explanation and brevity, the discussion will refer to UE 215a1 (e.g., a sidelink receiving UE) and UE 215a2 (e.g., a sidelink anchor UE). Figure 2 The remaining description.

[0061] Sidelink discovery for other sidelink transmitting UEs (such as other anchor nodes) can be facilitated by using a transport channel (referred to as the transport-side sidelink discovery channel (SL-DCH)) and its physical counterpart (physical sidelink discovery channel (e.g., PSDCH)). In some aspects, a sidelink transmitting UE can send one or more announcement messages generated using physical layer transport blocks with zero media access control overhead. For example, UE 215a2 can broadcast an announcement message on the PSDCH to announce its status as an anchor node.

[0062] In various embodiments, the sidelink anchor UE can utilize the sidelink discovery process to: 1) announce its presence to potential neighboring sidelink UEs by sending a message containing its application information or other useful information fields (e.g., GPS coordinates, time, etc.); and 2) detect the presence of other neighboring sidelink UEs by detecting and decoding the corresponding discovery message, and respond to the sidelink transmitting UE with a similar discovery message. In some cases, the discovery message may include information about the type of discovery being performed and / or the type of content provided by the sidelink transmitting UE (e.g., announcement, query). For example, UE 215a2 may broadcast a discovery message on the PSDCH, wherein the discovery message includes an indication regarding the announcement of the discovery message and its anchor node status.

[0063] In some aspects, depending on the implementation, UE 215a2 can perform sensing operations on one or more of the discovery channel (such as PSDCH) or the sidelink broadcast channel (such as PSBCH). If UE 215a2 does not detect an existing anchor UE on the discovery channel, UE 215a2 can configure itself as the anchor UE and broadcast an announcement indicating that it is the anchor UE. If UE 215a2 detects an existing anchor UE, UE 215a2 can determine whether it needs to become an anchor node within the wireless communication network 200.

[0064] In some cases, multiple anchor nodes may exist in the wireless communication network 200. A sidelink anchor UE (such as UE 215a2) may perform sensing operations on the sidelink discovery channel. In some aspects, when two anchor UEs sense each other, one anchor UE may adopt the system parameters of the other anchor UE to maintain local consistency of system parameters in the wireless communication network 200. In some cases, in-coverage anchor UEs (e.g., sidelink anchor UEs within the coverage area of ​​an existing cell) may have priority in determining system parameters. For example, UE 215a1 may be configured as an anchor node such that UE 215a2 senses UE 215a2 as an anchor node and determines itself as an in-coverage anchor UE based on its location within the coverage area of ​​BS 205a. In some embodiments, an anchor UE adopting new system parameters may broadcast its updated system parameters to other sidelink receiving UEs via a sidelink broadcast channel. For example, UE 215a2 may use the system parameters of UE 215a1, and further, UE 215a2 may broadcast its updated system parameters to other adjacent sidelink receiving UEs (e.g., 215a3, 215a4, 215b2). In other embodiments, the sidelink anchor UE may actively communicate with other sidelink receiving UEs via unicast or multicast transmission to indicate changes in system parameters.

[0065] For in-coverage sidelink operations, where both the transmitting and receiving UEs reside in the same coverage area of ​​the BS, the BS provides time synchronization, and UE 215a2 may not need to be the anchor UE to initiate sidelink operations by performing sidelink-specific synchronization. However, there may be several scenarios where UE 215a2 may need to be the anchor UE to perform sidelink-specific operations: (i) in multi-cell coverage, where the receiving UE resides in a different asynchronous cell relative to the transmitting UE; (ii) in partial coverage, where the receiving UE is outside coverage and may need to obtain synchronization from the transmitting UE within coverage; and / or (iii) outside coverage, where both UEs are outside the cell's coverage, and the transmitting UE decides to act as a reference synchronization source (referred to as the anchor UE).

[0066] In some respects, UE 215a2 may evaluate other factors, including but not limited to UE 215a2’s transmission priority level, UE 215a2’s application type, the number of sidelink UE participants in UE 215a2’s synchronization range, and / or the level of network congestion in UE 215a2’s sidelink coverage area.

[0067] In some aspects, if UE 215a2 determines through quantitative and / or qualitative analysis that one or more of the aforementioned factors are satisfied, then UE 215a2 can be determined to be an anchor node. In this regard, UE 215a2 can employ system parameters and any associated timing parameters of the detected anchor UE (e.g., UE 215a1). In some aspects, the detected anchor UE can propagate its system parameters to UE 215a2. This will allow multiple anchor UEs to coexist in network 200, with each anchor UE having corresponding system parameters to maintain local consistency in sidelink system operation.

[0068] In various embodiments, UE 215a2, acting as an anchor node, can autonomously form mode-specific time and frequency radio resource pools. UE 215a2 can allocate specific resources from these radio resource pools for control and data purposes to other sidelink receiving UEs. In some cases, UE 215a2 can form a radio resource pool for discovery communications (hereinafter referred to as the "sidelink discovery resource pool"). In other cases, UE 215a2 can form radio resource pools for control and data communications, such as a control channel resource pool (hereinafter referred to as the "PSCCH resource pool") and a data channel resource pool (hereinafter referred to as the "PSSCH resource pool"). In various embodiments, UE 215a2 can provide a transport resource pool configuration that includes configuration information for discovery resource pool configuration and control / data communication resource pool configuration.

[0069] A sidelink receiving UE (e.g., UE 215a1) can monitor multiple resources to listen for discovery announcements transmitted by an anchor UE (e.g., UE 215a2) to minimize and / or avoid sidelink UE interference. In some embodiments, UE 215a2 can autonomously determine a sidelink discovery resource pool containing certain subframes carrying sidelink control signals, while the remaining subframes can carry sidelink data. In this regard, time and frequency resources from the sidelink discovery resource pool for sending and / or monitoring discovery messages to other sidelink receiving UEs can be assigned to the sidelink receiving UE. When selecting resources from the pool, UE 215a2 can attempt to avoid assigning common time / frequency resources to different sidelink receiving UEs. In some embodiments, UE 215a2 can use randomization parameters to select time and frequency resources from the resource pool to minimize (or at least reduce) the number of resource allocation conflicts.

[0070] In some embodiments, the discovery resource pool configuration may indicate which RBs are available for discovery transmissions, whether a broadcast synchronization signal can be triggered in response to a discovery message, whether such broadcast synchronization signals should be sent once or periodically, and / or instructions on how sidelink radio resources can be allocated to different discovery transmissions (e.g., autonomously by a sidelink anchor UE or a sidelink transmitting UE). The discovery resource pool configuration may include additional parameter information indicating which resources a sidelink receiving UE can monitor to identify potential discovery announcement messages and other parameter information for tuning channel estimation and channel decoding operations at the sidelink receiving UE. In discovery mode operation, discovery messages may follow the transmission of broadcast synchronization signals allocated according to the time / frequency resources defined in the discovery resource pool configuration.

[0071] In independent sidelink communication, the radio resource pools for PSCCH and PSSCH can be separate. In some cases, the PSSCH radio resource pool can begin at a fixed time offset relative to the PSCCH radio resource pool. In some embodiments, UE 215a2, acting as an anchor node, can autonomously select time / frequency resources from the PSCCH radio resource pool based on randomization parameters to allocate resources for the sidelink control channel PSCCH. UE 215a2 can also autonomously select time / frequency resources from the PSSCH radio resource pool based on a UE-specific subframe bitmap to allocate resources for the sidelink shared channel PSSCH. In various embodiments, sidelink communication between sidelink UEs can be facilitated by using transport channels, transport sidelink shared channel (SL-SCH), and their physical counterpart (PSSCH).

[0072] Timing synchronization and system information acquisition for a sidelink receiving UE (e.g., 215a1) can be facilitated by the sidelink broadcast transport channel (SL-BCH) and its physical counterpart (PSBCH). These channels can be used to broadcast a set of preambles and system parameter information near UE 215a2. The set of primary and secondary preambles (PSS and SSS) can be used for synchronization of the sidelink receiving UE (e.g., 215a1). As described herein, the sidelink master information block (SL-MIB) can carry sidelink system parameter information. By acquiring the PSS / SSS preambles, a neighboring sidelink receiving UE (e.g., UE 215a1) can obtain time synchronization with the sidelink anchor UE (e.g., UE 215a2) and obtain its physical identifier. The SL-MIB may include system information for initial network access and scheduling information for RMSI. The SL-MIB may also include one or more predefined sets of initial BWP configuration and / or initial transport resource pool configuration. In some respects, S-SSB is transmitted within the bandwidth defined in the initial BWP configuration.

[0073] After decoding the SL-MIB, the sidelink receiving UE (e.g., UE 215a1) can recover the RMSI based on pointers included in the purpose-change bit field of the SL-MIB. The RMSI may include additional system parameters. In some aspects, the RMSI includes intra-cell guard band information for the NR-U system, for the sidelink receiving UE (e.g., UE 215a1) to deduce the resource block set. In various embodiments, the RMSI includes transmit resource pool configuration information and / or receive resource pool configuration information. The transmit resource pool configuration information may define a subset of available subframes and resource blocks for sidelink transmissions from the sidelink anchor UE (e.g., 215a2). The receive resource pool configuration information may define a subset of available subframes and resource blocks for sidelink reception by the sidelink anchor UE. In some aspects, the RMSI includes transmission mode information, such as an S-SSB transmission mode for rate matching purposes and / or an RMSI transmission mode for monitoring purposes.

[0074] In some aspects, the RMSI may include an active side-crossing link (BWP) configuration to assign an active BWP to a side-crossing link receiving UE. A side-crossing link anchor UE may use the active BWP configuration included in the RMSI to dynamically assign the side-crossing link receiving UE to operate on a particular side-crossing link BWP (e.g., a portion of a system BW). The side-crossing link receiving UE may monitor signaling information from the side-crossing link anchor UE within the active side-crossing link BWP. In some embodiments, the active side-crossing link BWP configuration may correspond to an initial side-crossing link BWP configuration, or in other embodiments, the active side-crossing link BWP configuration may differ from the initial side-crossing link BWP configuration. In some aspects, the active side-crossing link BWP configuration and the initial side-crossing link BWP configuration may include separate digital schemes. In this respect, UE 215a2 may schedule UE 215a1 for side-crossing communication within the active side-crossing link BWP.

[0075] Figure 3 A sidelink communication scheme 300 according to some aspects of this disclosure is illustrated. Scheme 300 can be adopted by UEs such as UE 115 and / or 215 in networks such as networks 100 and / or 200. Specifically, the sidelink UE can adopt scheme 300 to transmit the sidelink on a shared radio frequency band (e.g., in shared spectrum or unlicensed spectrum). The shared radio frequency band can be shared by multiple RATs, such as... Figure 2 As discussed in [the document]. Figure 3 In the diagram, the x-axis represents time in some arbitrary units, and the y-axis represents frequency in some arbitrary units.

[0076] In scheme 300, the shared radio frequency band 301 is divided into multiple sub-channels or frequency sub-bands 302 (denoted as 302) on the frequency. S0 302 S1 302 S2 …) and multiple sidelink frames 304 (shown as 304a, 304b, 304c, 304d…) in time for sidelink communication. Band 301 can be at any suitable frequency (e.g., at approximately 2.4 GHz, 5 GHz, or 6 GHz). Band 301 can have any suitable bandwidth and can be divided into any suitable number of frequency subbands 302. The number of frequency subbands 302 can depend on the sidelink communication bandwidth requirements. Band 301 can be at any suitable frequency. In some aspects, band 301 is a 2.4 GHz unlicensed band and can have a bandwidth of approximately 80 MHz divided into approximately fifteen 5 MHz frequency subbands 302.

[0077] Sidelink UEs (e.g., UE 115 and / or 215) can be equipped with a wideband receiver and a narrowband transmitter. For example, a UE can utilize a narrowband transmitter to access frequency subband 302. S2 Sidelink transmission is performed using frame structure 304. Frame structure 304 is repeated in each frequency subband 302. In some cases, such as... Figure 3 As shown, frequency gaps or guard bands may exist between adjacent frequency sub-bands 302, for example, to mitigate interference between adjacent frequency bands. Therefore, multiple sidelink data can be transmitted simultaneously in different frequency sub-bands 302 (e.g., FDM). Frame structure 304 also repeats in time. For example, frequency sub-band 302... S2 It can be divided into multiple frames with frame structure 304 in time.

[0078] Frame structure 304 includes sidelink resources 306 in each frequency subband 302. Figure 305 indicates the type of sidelink channel within sidelink resource 306. Sidelink resource 306 can have a structure substantially similar to NR sidelink resources. For example, sidelink resource 306 may include several subcarriers or RBs in frequency and several symbols in time. In some cases, sidelink resource 306 may have a duration between approximately 1 millisecond (ms) and approximately 20 ms. Each sidelink resource 306 may include PSCCH 310 and PSCCH 320. PSCCH 310 and PSCCH 320 may be multiplexed in time and / or frequency. Figure 3 In the example shown, for each sidelink resource 306, PSCCH 310 is located during the start symbol (e.g., approximately one symbol or approximately two symbols) of the sidelink resource 306 and occupies a portion of the corresponding frequency subband 302, while PSSCH 320 occupies the remaining time-frequency resources in the sidelink resource 306. In some cases, the sidelink resource 306 may also include, for example, a Physical Sidelink Feedback Channel (PSFCH) located during the end symbol of the sidelink resource 306. Typically, PSCCH 310, PSSCH 320, and / or PSFCH can be multiplexed within the sidelink resource 306 in any suitable configuration.

[0079] As described above, this subject matter provides a sidelink anchor UE (e.g., 115j, 215a2) configured to allocate resources to other sidelink receiving UEs. Thus, the sidelink anchor UE can configure the sidelink receiving UE with a resource pool configuration indicating resources in frequency band 301 and / or subband 302 and / or timing information associated with sidelink frame 304. For example, the sidelink anchor UE can provide resource allocation information to the sidelink receiving UE. In some aspects, the sidelink anchor UE can transmit a transmit resource pool configuration in the RMSI, wherein the transmit resource pool configuration indicates which radio resources are allocated to the sidelink anchor UE for transmitting sidelink communication. In some aspects, the sidelink anchor UE can transmit a receive resource pool configuration in the RMSI, wherein the receive resource pool configuration indicates which radio resources are allocated to the sidelink anchor UE for receiving sidelink communication. In this regard, the sidelink receiving UE can receive and decode physical communication channels (e.g., PSCCH310, PSSCH320) from the sidelink anchor UE based on the transmit resource pool configuration, and encode PSCCH310 and PSSCH320 based on the receive resource pool configuration and transmit them to the sidelink anchor UE.

[0080] In sidelink communication, to enable the sidelink receiving UE to successfully decode PSCCH 310 and PSSCH 320, information describing the specific resources assigned for transmission by the sidelink anchor UE and the transmission configuration can be carried in the sidelink control information (SCI). In this regard, control information for sidelink communication can be transmitted in the form of an SCI message. An SCI message can be sent on PSCCH 310, which carries information related to data transmission on PSSCH 320.

[0081] SCI can notify the UE receiving the side link of the resource reservation interval, the frequency positions of the initial transmission and retransmission, the time interval between the initial transmission and retransmission, and the modulation and coding scheme (MCS) used to modulate the data transmitted on PSSCH 320.

[0082] The SCI message can be populated based on the radio resource allocation mode (e.g., Mode-1 RRA or Mode-2 RRA). For Mode-1 RRA, the SCI can be populated using higher-layer information carried by L3 control signaling (e.g., RRC, and L1 control signaling configured at the cell (e.g., BS 215a)). For Mode-2 RRA, the SCI can be populated based on the autonomous decisions made by each sidelink anchor UE. The structure of the SCI message may include a frequency hopping flag field, a resource block assignment and hopping resource allocation field, a time resource mode field, an MCS field, a time advance field, and a group destination identifier field. The structure of the SCI message may include other additional fields suitable for supporting V2X control signaling. The frequency hopping flag field and the resource block assignment and hopping resource allocation field can provide information for the sidelink receiving UE to identify the RBs (Resource Blocks) where the data channel (e.g., PSSCH 320) resides. The sidelink anchor UE can autonomously configure each of these two fields. The identified RBs may belong to a sidelink communication resource pool (e.g., a PSSCH resource pool). The Time Resource Mode field can provide the time-domain resource allocation for the data channel (e.g., PSSCH 320), and in particular, can provide potential subframes for PSSCH transmission. The MCS field can provide the MCS for PSSCH 320, which can be autonomously selected by the sideline anchor UE. The Timing Advance field can provide sideline time adjustments for Mode-2RRA or other applicable modes. The Group Destination Identifier field can indicate the sideline receiving UE group that is potentially interested in messages sent from the sideline anchor UE. This can be used by the sideline receiving UE to ignore messages destined for other sideline UE groups.

[0083] In some aspects, transport channel coding can be used to process SCI messages to generate SCI message transport blocks, followed by physical channel coding to generate corresponding PSCCH blocks. The PSCCH blocks are carried on the corresponding subframe resource elements used for transmission. The side-link receiving UE can receive one or more resource elements on the corresponding subframe to recover control signaling information and can extract data channel allocation and transmission configuration.

[0084] PSCCH 310 can be used to carry SCI 330. PSSCH 320 can be used to carry sidelink data. Depending on the sidelink application, the sidelink data can have various forms and types. For example, when the sidelink application is a V2X application, the sidelink data can carry V2X data (e.g., vehicle location information, driving speed and / or direction, vehicle sensor measurements, etc.). Alternatively, when the sidelink application is an IIoT application, the sidelink data can carry IIoT data (e.g., sensor measurements, device measurements, temperature readings, etc.). PSFCH can be used to carry feedback information, such as HARQ ACK / NACK for sidelink data received in earlier sidelink resource 306.

[0085] In some aspects, scheme 300 is used for synchronizing sidelink communication. In other words, the sidelink UE is synchronized in time and aligned with symbol boundaries and sidelink resource boundaries (e.g., the start time of sidelink frame 304). The sidelink UE can perform synchronization in various forms, such as based on a sidelink SSB received from the sidelink UE and / or an NR-U SSB received from a BS (e.g., BS 105 and / or 205) when within its coverage. In some aspects, for example, when within the coverage of a serving BS configured according to mode-1 RRA, the sidelink UE can be pre-configured with a resource pool 308 in band 301. Resource pool 308 may include multiple sidelink resources 306.

[0086] In the NR sidelink frame structure, sidelink frames 304 in resource pool 308 can be sequential in time. A sidelink receiving UE (e.g., UE 115 and / or 215) can include a reservation for sidelink resource 306 in a later sidelink frame 304 in SCI 330. Therefore, another sidelink UE (e.g., a UE in the same NR-U sidelink system) can perform SCI sensing in resource pool 308 to determine whether sidelink resource 306 is available or occupied. For example, if a sidelink UE detects an SCI indicating a reservation for sidelink resource 306, the sidelink UE can avoid transmitting in the reserved sidelink resource 306. If the sidelink UE determines that no reservation has been detected for sidelink resource 306, the sidelink UE can transmit in sidelink resource 306. Therefore, SCI sensing can help the UE identify the target frequency subband 302 to be reserved for sidelink communication and avoid intra-system conflicts with another sidelink UE in the NR sidelink system. In some aspects, the UE can be configured with a sensing window for SCI sensing or monitoring to reduce intra-system conflicts.

[0087] In some aspects, the sidelink UE can be configured with a frequency hopping mode. In this respect, the sidelink UE can hop from one frequency subband 302 in one sidelink frame 304 to another frequency subband 302 in another sidelink frame 304. Figure 3 In the example shown, during sidelink frame 304a, the sidelink UE is located in frequency subband 302. S2 SCI 330 is transmitted in side link resource 306 to transmit in frequency subband 302. S1 Sideline resources 306 are reserved in the next sideline frame 304b. Similarly, during sideline frame 304b, the sideline UE is located in frequency subband 302. S1 SCI 332 is transmitted in side link resource 306 to transmit in frequency subband 302. S1 Side-link resources 306 are reserved in the next side-link frame 304c. During side-link frame 304c, the side-link UE is located in frequency subband 302. S1 SCI 334 is transmitted in side link resource 306 to transmit in frequency subband 302. S0 Side-link resources 306 are reserved in the next side-link frame 304d. During side-link frame 304d, the side-link UE is located in frequency subband 302. S0 SCI 336 is sent in side link resource 306. SCI 336 can reserve side link resource 306 in a later side link frame 304.

[0088] The SCI can also indicate scheduling information and / or identify the destination identifier (ID) of the target sidelink receiving UE for the next sidelink resource 306. Therefore, the sidelink UE can monitor SCIs sent by other sidelink UEs. Upon detecting an SCI in sidelink resource 306, the sidelink UE can determine whether it is the target receiver based on the destination ID. If the sidelink UE is the target receiver, it can continue to receive and decode the sidelink data indicated by the SCI. In some aspects, multiple sidelink UEs can simultaneously transmit sidelink data in sidelink frame 304 (e.g., via FDM) in different frequency subbands. For example, in sidelink frame 304b, a pair of sidelink UEs can use frequency subband 302. S2 Sidelink resources 306 are used to transmit sidelink data, while another pair of sidelink UEs can use frequency subband 302. S1 Sidelink resource 306 is used to transmit sidelink data.

[0089] The above is about Figure 3The described sidelink mechanisms allow sidelink UE groups to communicate in a shared frequency band (e.g., NR-U). In some aspects, these mechanisms can be used for independent communication, including scenarios where one or more UEs are not associated with a subscription. In some aspects, Figure 3 The mechanisms described herein may involve dynamic sidelink discovery and communication processes, which may involve significant coordination and / or standardization between UEs. In some cases, such coordination between sidelink UEs may be difficult or impractical. For example, UEs may be provided by different manufacturers and / or associated with different service providers. Therefore, specifying and indicating time / frequency resources for PSSCH 320 and PSCCH 310 may be difficult. This disclosure describes schemes and methods for indicating sidelink discovery information based on periodic synchronization communications (such as sidelink synchronization signal blocks (S-SSBs)). For example, aspects of this disclosure provide for transmitting discovery signals in unoccupied portions of subbands carrying synchronization communications (which may include, as described above, regarding...). Figure 2 and Figure 3 The discussed RMSI and the mechanism for aligning with synchronization communication time. Therefore, a first sidelink UE (e.g., an anchor UE) can indicate discovery information to other sidelink UEs in a manner that enables efficient use of resources associated with predefined synchronization signaling. In addition to improving network efficiency, these mechanisms can reduce or eliminate considerations regarding standards for coordinating between manufacturers and / or service providers to agree on shared frequency bands for sidelink communication.

[0090] Figure 4 Sidelink communication scheme 400 according to some aspects of this disclosure is illustrated. Scheme 300 can be adopted by UEs such as UE 115 and / or 215 in networks such as networks 100 and / or 200. Specifically, the sidelink UE can adopt scheme 300 to transmit the sidelink on a shared radio frequency band (e.g., in a shared spectrum or unlicensed spectrum). The shared radio frequency band can be shared by multiple RATs, such as... Figure 2 As discussed in [the document]. Figure 4 In the diagram, the x-axis represents time in some arbitrary units, and the y-axis represents frequency in some arbitrary units.

[0091] In scheme 400, a first sidelink UE 415a transmits and a second sidelink UE 415b receives sidelink communication including synchronization communication 410 and discovery signal 420. The first sidelink UE 415a can transmit the sidelink communication in a shared frequency band (e.g., NR-U). The first sidelink UE 415a transmits the sidelink communication in a subband 430, which may be referred to as a channel. Subband 430 includes a first portion 432 and a second portion 434. The first portion 432 may include one or more first RBs, and the second portion 434 may include one or more second RBs. The one or more first RBs may be consecutive, and the one or more second RBs may be consecutive. Furthermore, the one or more second RBs of the second portion 434 may be consecutive with the one or more first RBs of the first portion 432. In other aspects, gaps of one or more RBs may exist between the first portion 432 and the second portion 434. In one example, subband 430 includes a total of 50 RBs, with the first portion 432 including 11 RBs and the second portion 434 including 30, 32, 36, 39, or any other suitable number of RBs. In another example, subband 430 includes a total of 100 RBs, with the first portion 432 including 11 RBs and the second portion 434 including 60, 70, 72, 80, or any other suitable number of RBs. The RBs of subband 430 can span a bandwidth that can be 5 MHz, 10 MHz, 20 MHz, 40 MHz, or any other suitable bandwidth. In some aspects, the number of RBs in the subband can depend on the subcarrier spacing of subband 430. The subcarrier spacing of subband 430 can depend on the frequency range and / or carrier frequency of subband 430. For example, for a first carrier frequency and bandwidth, the subcarrier frequency can be 15 kHz. For a second carrier frequency and bandwidth, the subcarrier frequency can be 30 kHz. For example, if the subcarrier spacing is 30 kHz, then subband 430 may include 50 RBs, or if the subcarrier spacing is 15 kHz, then subband 430 may include 100 RBs.

[0092] In the first portion 432 of subband 430, a first sidelink UE 415a transmits and a second sidelink UE 415b receives synchronization communication 410. The first sidelink UE 415a may transmit synchronization communication 410 in the first 13 OFDM symbols of a time slot, where the last OFDM symbol is an idle symbol or gap symbol 419. In an exemplary aspect, synchronization communication 410 includes a synchronization signal block (SSB), such as a sidelink SSB (S-SSB). In this respect, synchronization communication 410 includes a physical broadcast channel (PBCH) 412, a primary synchronization signal (PSS) 414, and a secondary synchronization signal (SSS) 416. PBCH 412 carries control information 418. In some aspects, PBCH 412 may be a physical sidelink broadcast channel (PSBCH). In an exemplary aspect, control information 418 includes a master information block (MIB). The MIB may have, for example, the following regarding... Figure 5 The MIB 500 is described in this form.

[0093] Control information, or MIB 418, can be used to detect and / or decode discovery signal 420. Therefore, discovery signal 420 may not carry its own control information, such as the physical side link control channel (PSCCH). Instead, control information can be included or carried in MIB 418. Control information 418 may include or indicate the modulation and coding scheme (MCS) of the discovery signal, the RB allocation of the discovery signal, the TB size of the discovery signal, the demodulation reference signal (DMRS) mode of the discovery signal, and / or any other suitable control parameters associated with discovery signal 420.

[0094] exist Figure 4 In one aspect, the first-side walkway UE 415a transmits synchronization communication 410 in a first portion 432, wherein the first portion 432 is located at or near the edge of subband 430. Specifically, the first portion 432 is located at the lower edge or bottom edge of the lower frequency subcarrier representing subband 430. In other aspects, subband 430 may not be located at the edge of subband 430. For example, one or more RBs may be present on the first side of the first portion 432, and one or more RBs may be present on the opposite second side of the first portion 434. In other aspects, the first portion 432 in which the first-side walkway UE 415a transmits synchronization communication 410 may be at or near the center frequency of subband 430.

[0095] The first side-link UE 415a may transmit a discovery signal 420 in the second portion 434 of subband 430 and in the same time slot used for transmitting synchronization communication 410. The first side-link UE 415a may transmit the discovery signal 420 such that the discovery signal 420 includes a waveform similar to or the same as that of Physical Side-Link Shared Channel (PSSCH) communication. Therefore, the first side-link UE 415a may generate or prepare the discovery signal 420 based on appropriate parameters of the PSSCH waveform to include DMRS mode, MCS, RB allocation, TB size, and / or any other waveform parameters. In some aspects, the information carried in the discovery signal 420 may be similar to or the same as Residual Minimal System Information (RMSI). The discovery signal 420 may include or indicate side-link connection configuration information including one or more side-link communication parameters. For example, the discovery signal 420 may include or indicate at least one of the following: side-link resource pool configuration, network service information associated with the first side-link UE 415a, and / or UE identification information associated with the first side-link UE 415a. Therefore, the sidelink connection configuration can provide configuration information that can be used by multiple sidelink UEs for self-organizing and coordinating transmission, using sidelink channel resources, detecting and synchronizing with other UEs, specifying coordinating or anchoring UEs, establishing resource pools and / or any other sidelink functions.

[0096] In some aspects, transmitting the discovery signal 420 includes transmitting the Physical Shared Channel (PSSCH). For example, in some aspects, the PSSCH may be similar to or the same as the PSSCH. In some aspects, the PSSCH transmitted by the first-side walkway UE may be different from the PSSCH because control information (e.g., SCI) may be carried in the synchronization communication. For example, the MIB of the PBCH may carry control information, as explained above. In some aspects, the first-side walkway UE 415a may transmit multiple repetitions of the discovery signal 420 within a time period. For example, the first-side walkway UE 415a may transmit multiple repetitions of the discovery signal 420 at 80ms intervals or any other suitable intervals. Therefore, the second-side walkway UE may perform soft decoding of the discovery signal 420 based on multiple repetitions.

[0097] The second portion of a subband of the shared frequency band may include one or more RBs that form a portion of the subband different from the RBs used for transmitting synchronization communication. As explained above, the second portion of the subband may be contiguous with the first portion of the subband. For example, the first-side walkway UE 415a may transmit the discovery signal 420 in a second plurality of RBs contiguous with the first plurality of RBs used for transmitting synchronization communication. In some aspects, the number of RBs used by the first-side walkway UE to transmit the discovery signal 420 may depend on the subcarrier spacing of the shared frequency band. For example, if the shared frequency band is associated with a subcarrier spacing of 30 kHz, the first-side walkway UE 415a may transmit the discovery signal 420 in a contiguous group of 36 RBs and may transmit synchronization communication in a contiguous group of 11 RBs. In another example, if the shared frequency band is associated with a subcarrier spacing of 15 kHz, the first-side walkway UE may transmit the discovery signal 420 in a contiguous group of 72 RBs. However, it should be understood that these values ​​are examples, and the first-side walkway UE 415a may transmit the discovery side walkway in any suitable number of RBs.

[0098] Furthermore, as described above, the first-side traversal UE 415a transmits the discovery signal 420 in the first time slot, which is the same time slot used for transmitting synchronization communication. In some aspects, the first-side traversal UE 415b can transmit and the second-side traversal UE 415b can receive the discovery signal 420 in the same 13 OFDM symbols used for transmitting synchronization communication, wherein the 14th symbol is an idle symbol or a gap symbol. Therefore, the discovery signal 420 and the synchronization communication can be aligned in the time domain.

[0099] In some aspects, the first sidelink UE 415a transmits a discovery signal 420 such that it is quasi-co-located (QCL) with synchronization communications. Furthermore, in some aspects, the first sidelink UE 415a can use the same antenna port as the antenna portion used for transmitting synchronization communications to transmit the discovery signal 420. In some aspects, by transmitting the discovery signal 420 such that it is time-aligned with synchronization communications and QCL with them, and by having the discovery signal 420 occupy a portion of the subband not occupied by synchronization communications (e.g., S-SSB), the first sidelink UE 415a can efficiently utilize network resources to transmit sidelink configuration information for sidelink coordination. Moreover, transmitting the discovery signal 420 in this manner provides a flexible and inclusive discovery signal 420 scheme that can be used by equipment associated with various network service providers and equipment manufacturers. For example, in some aspects, scheme 400 can be used by a UE without a network subscription.

[0100] Figure 5This is a simplified block diagram of an exemplary frame structure for a sidelink master information block (MIB) 500 according to some aspects of this disclosure. The frame structure includes a sidelink bandwidth field 502, an in-coverage indicator field 504, a time division duplex (TDD) configuration field 506, a reservation field 508, a frame number field 510, and a subframe number field 512. However, not all depicted frame structure fields may be included, and one or more implementations may include additional frame structure fields not shown in the figures. Variations in the arrangement and type of frame structure fields may be made without departing from the scope of the claims set forth herein. Additional frame structure fields, different frame structure fields, or fewer frame structure fields may be provided.

[0101] As described herein, the sidelink master information block can carry system parameter information. The sidelink master information block can be similar to the MIB in NR and NR-U systems. In NR or NR-U systems, the MIB can contain an 8-bit information field configuring CORESET 0 and Type-0 PDCCH monitoring. However, in sidelink communication, the sidelink master information block may not contain such bit field information corresponding to CORESET 0 and Type-0 PDCCH monitoring. In some embodiments, the SL-MIB in the S-SSB can reuse the 8-bit information field to indicate the location of the discovery signal. For example, multiple bits in the reserved field 508 and / or TDD configuration field 506 of the sidelink master information block can be reused by the sidelink UE as the initial sidelink resource configuration field 514.

[0102] Sidelink master information blocks can be mapped to reference subframes at specific frequency and / or time resource allocations. For example... Figure 5 The frame structure of the sidelink main information block 510, as depicted, may include a 40-bit sequence. In some cases, the sidelink bandwidth field 502 may provide a bandwidth mode (e.g., 5, 10, 15, 20 MHz). The coverage indicator field 504 may notify the sidelink receiving UE of the coverage status of the sidelink UE (e.g., within coverage, partially covered, outside coverage). The frame field 510 and the subframe field 512 may provide timing reference information in the frame and subframe time scales, respectively.

[0103] like Figure 5As depicted, the TDD configuration field 506 and the reservation field 508 have been reused as the initial side-link configuration field 514. However, in other aspects, the initial side-link resource configuration field 514 may be a field separate from the TDD configuration field 506 and / or the reservation field 508. In some cases, the initial side-link configuration field 514 may include a pointer indicating the location of the discovery signal so that the side-link receiving UE can resume the discovery signal after locating the S-SSB. In this regard, the initial side-link configuration field 514 includes an RB allocation field 524 indicating at least one of the starting RB or the RB range associated with the discovery signal.

[0104] In some aspects, the location of the discovery signal or RB allocation can be indicated in field 524 relative to the S-SSB. In some aspects, the sidelink UE can allocate bit fields in the initial sidelink resource configuration field 514 to indicate at least one of a plurality of predefined initial sidelink BWP configuration sets. The initial sidelink configuration field 514 includes a modulation and coding scheme (MCS) field 522, a transport block (TB) size field 526, and a demodulation reference signal (DMRS) mode field 528. The modulation and coding scheme field 522 can indicate the modulation type (e.g., QPSK) used to modulate the discovery signal. The TB size field 526 can indicate the number of bits per TB carried in the discovery signal. The DMRS mode field 528 can indicate the DMRS mode.

[0105] In some aspects, one or more of fields 522, 524, 526, and 528 may include one or more bits indicating the selection of an option for MCS, RB allocation, TB size, DMRS mode, etc. For example, a sidelink UE may be configured with two or more MCS, RB allocation, TB size, and / or DMRS modes, and the values ​​of fields 522, 524, 526, and 528 may indicate which option was selected for the discovery signal. In other aspects, one or more of fields 522, 524, 526, and 528 may include or carry absolute values ​​(such as numerical values) to indicate the corresponding parameters. For example, the value of the TB size field 526 may include multiple bits indicating the TB size associated with the discovery signal. In another aspect, the value of the RB allocation field 524 may indicate the value of the start and / or end RB of the discovery signal relative to the S-SSB.

[0106] After decoding the sidelink master information block, the sidelink receiving UE can receive and recover the discovery signal based on the pointer provided in the initial sidelink configuration field 514. In other cases, the UE can allocate bit positions in the initial sidelink configuration field 514 to include an indication of whether the sidelink master information block includes a discovery signal. For example, the sidelink master information block indication could indicate that no discovery signal is present, and the sidelink receiving UE may not attempt to monitor for a discovery signal.

[0107] Figure 6 This is a signaling diagram of a method 600 for sidelink communication with discovery signaling, based on some aspects of this disclosure. Method 600 is performed by a first UE 615a and a second UE 615b. Each of the first UE 615a and the second UE 615b may be one of the UEs 115 in network 100. Figure 2 One and / or one of the UE 215 shown Figure 4 One of the UEs 415 shown. Specifically, the sidelink UE can employ method 600 to transmit the sidelink on a shared radio frequency band (e.g., in a shared spectrum or unlicensed spectrum). The shared radio frequency band can be shared by multiple RATs, such as Figure 2 As discussed in the document. In some aspects, one of the UEs (such as the first UE 615a) can be used as an anchor UE for coordinating sidelink communication between one or more non-anchor UEs (e.g., the second UE 615b).

[0108] At action 602, the first UE 615a transmits and the second UE 615b receives a synchronization communication in the first part of the subband and a discovery signal in the second part of the subband. The first UE 615a may transmit the synchronization communication and the discovery signal in the same time slot, such that the synchronization communication and the discovery signal are time-aligned. The synchronization communication may include or indicate control information that can be used by the second UE 615b to decode the discovery signal. In some aspects, action 602 includes transmitting a synchronization signal block (SSB) including a physical broadcast channel (PBCH), a primary synchronization signal (PSS), and a secondary synchronization signal (SSS). For example, the SSB may be a sidelink SSB (S-SSB). In some aspects, the first UE 615a may transmit a PBCH carrying a primary information block (MIB). The MIB may have a... Figure 5The structure of the MIB 500 shown is similar to or the same as that of the MIB. For example, the MIB may include sidelink resource configurations that include or indicate modulation and coding schemes, resource block (RB) allocations, transport block (TB) sizes, demodulation reference signal (DMRS) modes, and / or any other suitable parameters associated with the discovery signal. In some aspects, the first UE 615a transmits an indication in the PBCH of the first RB of the discovery signal and the size of the discovery signal (e.g., in RBs). In some aspects, the first UE 615a may also indicate the position and / or period of the reference signal carried in the discovery signal. Synchronization information may include any suitable parameters or information used to assist the second UE 615b in detecting and decoding the discovery signal.

[0109] The first portion of a subband may include one or more consecutive RBs within the subband. In some aspects, a subband may be described as a channel with a bandwidth of 20 MHz, 80 MHz, 10 MHz, or any other suitable bandwidth (larger or smaller). The bandwidth of the subband may also be described or defined in terms of RBs. For example, a subband may include 50 RBs, 100 RBs, or any other suitable number of RBs (larger or smaller). The first UE 615a may transmit synchronization communication such that the synchronization communication occupies the first portion of a plurality of RBs in the subband. In one aspect, the first portion of the subband includes 11 RBs. In some aspects, at least one RB may be located at or near an edge of the subband (e.g., the lowest or highest frequency). For example, the first RB of the first portion of the subband may be the first RB of the subband. In other aspects, the first RB of the first portion may not be the first RB of the subband. For example, a subband may include one or more RBs on either side of the first portion of the subband, wherein synchronization communication is transmitted in the first portion of the subband.

[0110] The first UE 615a can send a discovery signal, such that the discovery signal includes a waveform similar to or the same as that of PSSCH communication. Therefore, the first UE 615a can generate or prepare the discovery signal based on corresponding parameters of the PSSCH waveform to include DMRS mode, MCS, RB allocation, TB size, and / or any other waveform parameters. In some aspects, the information carried in the discovery signal can be similar to or the same as the Residual Minimal System Information (RMSI). The discovery signal can include or indicate sidelink connection configuration information including one or more sidelink communication parameters. For example, the discovery signal can include or indicate at least one of the following: sidelink resource pool configuration, network service information associated with the first UE 615a, and / or UE identification information associated with the first UE 615a. Therefore, the sidelink connection configuration can provide configuration information that can be used by multiple sidelink UEs for self-organizing and coordinating transmissions, using sidelink channel resources, detecting and synchronizing with other UEs, designating coordinating or anchoring UEs, establishing resource pools, and / or any other sidelink functions.

[0111] In some aspects, sending a discovery signal includes sending a physical shared channel. For example, in some aspects, the physical shared channel may be similar to or the same as the physical side link shared channel (PSSCH). In some aspects, the physical shared channel sent by the first UE615a may be different from the PSSCH because control information (e.g., SCI) may be carried in the synchronization communication. For example, the MIB of the PBCH may carry control information, as explained above.

[0112] The second portion of a subband of the shared frequency band may include one or more RBs that form a portion of the subband different from the RBs used for transmitting synchronization communication. As explained above, the second portion of the subband may be contiguous with the first portion of the subband. For example, the first UE 615a may transmit a discovery signal in a second plurality of RBs contiguous with the first plurality of RBs used for transmitting synchronization communication. In some aspects, the number of RBs used by the first UE 615a for transmitting the discovery signal may depend on the subcarrier spacing of the shared frequency band. For example, if the shared frequency band is associated with a subcarrier spacing of 30 kHz, the first UE 615a may transmit a discovery signal in a contiguous group of 36 RBs and may transmit synchronization communication in a contiguous group of 11 RBs. In another example, if the shared frequency band is associated with a subcarrier spacing of 15 kHz, the first UE 615a may transmit a discovery signal in a contiguous group of 72 RBs. However, it should be understood that these values ​​are examples, and the first UE 615a may transmit a discovery-side link in any suitable number of RBs.

[0113] Furthermore, as described above, the first UE 615a transmits a discovery signal in the first time slot, which is the same time slot used for transmitting synchronization communication. In some aspects, the first UE 615a can transmit and the second UE 615b can receive the discovery signal in the same 13 OFDM symbols used for transmitting synchronization communication, wherein the 14th symbol is an idle symbol or a gap symbol. Therefore, the discovery signal and the synchronization communication can be aligned in the time domain.

[0114] In some aspects, the first UE 615a transmits a discovery signal such that it is quasi-co-located (QCL) with synchronous communication. Furthermore, in some aspects, the first UE 615a may use an antenna port that is the same antenna portion used for transmitting synchronous communication to transmit the discovery signal.

[0115] At action 604, the second UE 615b decodes synchronization communication. In some aspects, decoding synchronization communication includes decoding S-SSB. S-SSB may include PBCH (e.g., PSBCH), PSS, and SSS. PBCH may include control information as described above. Accordingly, action 604 may include decoding or detecting, for example, a MIB that includes control information used by the second UE 615b to decode a discovery signal.

[0116] At action 606, the second UE 615b decodes the discovery signal based on control information in the synchronization communication. For example, the second UE 615b may decode or detect the discovery signal based on the sidelink resource configuration carried in the MIB. The sidelink resource configuration may include or indicate modulation and coding schemes, resource block (RB) allocations, transport block (TB) sizes, demodulation reference signal (DMRS) modes, and / or any other suitable parameters associated with the discovery signal. The second UE 615b may decode or detect the discovery signal based on one or more of these parameters.

[0117] At action 608, the first UE 615a transmits a repeat of the discovery signal, and the second UE 615b receives the repeat of the discovery signal. In this respect, the first UE 615a may transmit multiple repeats of the discovery signal within a time period. For example, the first UE 615a may transmit multiple repeats of the discovery signal at an 80ms interval or any other suitable interval.

[0118] At action 610, the second UE 615b uses soft decoding of the discovery signal based on multiple repetitions of the discovery signal.

[0119] At action 612, the second UE 615b sends sidelink communication based on a discovery signal, and the first UE 615a receives sidelink communication based on the discovery signal. For example, as described above, the discovery signal may indicate sidelink connection configuration information including one or more sidelink communication parameters. For example, the discovery signal may include or indicate at least one of the following: sidelink resource pool configuration, network service information associated with the first UE 615a, and / or UE identification information associated with the first UE 615a. Therefore, the sidelink connection configuration can provide configuration information that can be used by multiple sidelink UEs for self-organizing and coordinating transmissions, using sidelink channel resources, detecting and synchronizing with other UEs, specifying coordinating or anchoring UEs, establishing resource pools, and / or any other sidelink functions. The second UE 615b can use this information to determine whether to initiate sidelink communication with the first UE 615a, and / or to determine the time / frequency resources to be used for sidelink communication.

[0120] Figure 7 This is a block diagram of an exemplary sidelink UE 700 based on some aspects of this disclosure. The sidelink UE 700 can be as described above. Figure 1 The UE 115 in network 100 discussed above Figure 2 UE 215 discussed above, or as mentioned above Figure 4 The UE 415 discussed herein. As shown in the figure, the sidelink UE 700 may include a processor 702, a memory 704, a sidelink configuration module 708, a transceiver 710 including a modem subsystem 712 and an RF unit 714, and one or more antennas 716. These components may communicate with each other directly or indirectly, for example, via one or more buses.

[0121] Processor 702 may have various features as a particular type of processor. For example, these may include a CPU, DSP, ASIC, controller, FPGA device, another hardware device, firmware device, or any combination thereof configured to perform the operations described herein. Processor 702 may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors and a DSP core, or any other such configuration.

[0122] Memory 704 may include cache memory (e.g., the cache memory of processor 702), 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 combinations of different types of memory. In some aspects, memory 704 may include a non-transitory computer-readable medium. Memory 704 may store instructions 706. Instructions 706 may include causing processor 702 to perform the operations described herein when executed by processor 702 (e.g., ...). Figures 1-6 , Figure 8 and / or Figure 9 Instructions (in all aspects). Instruction 706 can also be referred to as code, which can be broadly interpreted as including any type of computer-readable statement.

[0123] The sidelink configuration module 708 can be implemented via hardware, software, or a combination thereof. For example, the sidelink configuration module 708 can be implemented as a processor, circuitry, and / or instructions 706 stored in memory 704 and executed by processor 702. In some cases, the sidelink configuration module 708 can be integrated within the modem subsystem 712. For example, the sidelink configuration module 708 can 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 circuitry) within the modem subsystem 712.

[0124] The sidelink configuration module 708 can be used in various aspects of this disclosure, for example, Figures 1-6 , Figure 8 and / or Figure 9 In various aspects, for example, the sidelink configuration module 708 is configured to transmit synchronization communication to the second sidelink UE in the first time slot and the first part of the subband of the shared frequency band. The synchronization communication may indicate the location of the discovery signal in the second part of the subband of the shared frequency band. In some aspects, transmitting synchronization communication includes transmitting a synchronization signal block (SSB) that includes a physical broadcast channel (PBCH), a primary synchronization signal (PSS), and a secondary synchronization signal (SSS). For example, the SSB may be a sidelink SSB (S-SSB). In some aspects, the sidelink configuration module 708 may be configured to transmit a PBCH carrying a primary information block (MIB). The MIB may have a... Figure 5The structure of the MIB 500 shown is similar to or the same as that of the MIB. For example, the MIB may include sidelink resource configurations that include or indicate modulation and coding schemes, resource block (RB) allocations, transport block (TB) sizes, demodulation reference signal (DMRS) modes, and / or any other suitable parameters associated with the discovery signal. In some aspects, the sidelink configuration module 708 may be configured to transmit an indication in the PBCH of the first RB of the discovery signal and the size of the discovery signal (e.g., in RBs). In some aspects, the sidelink configuration module 708 may be configured to indicate the position and / or period of the reference signal carried in the discovery signal. Synchronization information may include any suitable parameters or information for assisting the second sidelink UE in detecting and decoding the discovery signal.

[0125] The first portion of a subband may include one or more consecutive RBs within the subband. In some aspects, a subband may be described as a channel with a bandwidth of 20 MHz, 80 MHz, 10 MHz, or any other suitable bandwidth (larger or smaller). The bandwidth of the subband may also be described or defined in terms of RBs. For example, a subband may include 50 RBs, 100 RBs, or any other suitable number of RBs (larger or smaller). The side link configuration module 708 may be configured to transmit synchronization communication such that the synchronization communication occupies the first portion of a plurality of RBs in the subband. In one aspect, the first portion of the subband includes 11 RBs. In some aspects, at least one RB may be located at or near an edge of the subband (e.g., the lowest or highest frequency). For example, the first RB of the first portion of the subband may be the first RB of the subband. In other aspects, the first RB of the first portion may not be the first RB of the subband. For example, a subband may include one or more RBs on either side of the first portion of the subband, wherein synchronization communication is transmitted in the first portion of the subband.

[0126] The sidelink configuration module 708 can also be configured to send a discovery signal to the second sidelink UE in a first time slot and in a second portion of a subband of the shared frequency band. The sidelink configuration module 708 can be configured to send the discovery signal such that the discovery signal includes a waveform similar to or the same as that of PSSCH communication. Accordingly, the sidelink configuration module 708 can be configured to generate or prepare the discovery signal based on appropriate parameters of the PSSCH waveform to include DMRS mode, MCS, RB allocation, TB size, and / or any other waveform parameters. In some aspects, the information carried in the discovery signal may be similar to or the same as the Residual Minimal System Information (RMSI). The discovery signal may include or indicate sidelink connection configuration information including one or more sidelink communication parameters. For example, the discovery signal may include or indicate at least one of the following: sidelink resource pool configuration, network service information associated with the sidelink UE 700, and / or UE identification information associated with the sidelink UE 700. Therefore, the sidelink connection configuration can provide configuration information that can be used by multiple sidelink UEs for self-organizing and coordinating transmission, using sidelink channel resources, detecting and synchronizing with other UEs, specifying coordinating or anchoring UEs, establishing resource pools and / or any other sidelink functions.

[0127] In some aspects, transmitting a discovery signal includes transmitting a Physical Shared Channel (PSSCH). For example, in some aspects, the PSSCH may be similar to or the same as the Physical Side Link Shared Channel (PSSCH). In some aspects, the PSSCH may differ from the PSSCH because control information (e.g., SCI) can be carried in the synchronization communication. For example, the MIB of the PBCH can carry control information, as explained above. In some aspects, the side link configuration module 708 can be configured to transmit multiple repetitions of the discovery signal within a time period. For example, the side link configuration module 708 can be configured to transmit multiple repetitions of the discovery signal at 80ms intervals or any other suitable intervals. Therefore, the second side link UE can perform soft decoding of the discovery signal based on multiple repetitions.

[0128] The second portion of a subband of the shared frequency band may include one or more RBs that form a portion of the subband different from the RBs used for transmitting synchronization communication. As explained above, the second portion of the subband may be contiguous with the first portion of the subband. For example, the sidelink configuration module 708 may be configured to transmit a discovery signal in a second plurality of RBs contiguous with the first plurality of RBs used for transmitting synchronization communication. In some aspects, the number of RBs used by the sidelink configuration module 708 for transmitting the discovery signal may depend on the subcarrier spacing of the shared frequency band. For example, if the shared frequency band is associated with a subcarrier spacing of 30 kHz, the sidelink configuration module 708 may be configured to transmit the discovery signal in a contiguous group of 36 RBs and may transmit synchronization communication in a contiguous group of 11 RBs. In another example, if the shared frequency band is associated with a subcarrier spacing of 15 kHz, the sidelink configuration module 708 may be configured to transmit the discovery signal in a contiguous group of 72 RBs. However, it should be understood that these values ​​are examples, and the sidelink configuration module 708 may be configured to transmit the discovery sidelink in any suitable number of RBs.

[0129] Furthermore, as described above, the sidelink configuration module 708 can be configured to transmit a discovery signal in a first timeslot, which is the same timeslot used for transmitting synchronization communication. In some aspects, the sidelink configuration module 708 can be configured to transmit, and a second sidelink UE can receive, the discovery signal in the same 13 OFDM symbols used for transmitting synchronization communication, where the 14th symbol is an idle symbol or a gap symbol. Therefore, the discovery signal and synchronization communication can be aligned in the time domain.

[0130] In some aspects, the sidelink configuration module 708 can be configured to transmit a discovery signal such that it is quasi-co-located (QCL) with synchronous communication. Furthermore, in some aspects, the sidelink configuration module 708 can be configured to transmit the discovery signal using an antenna port that is the same antenna portion used for transmitting synchronous communication.

[0131] In another aspect, the sidelink configuration module 708 can be used to receive and / or detect discovery signals. For example, the sidelink configuration module 708 can be configured to receive synchronization communication from a second sidelink UE in a first time slot and a first portion of a subband of a shared frequency band. The synchronization communication can indicate the location of the discovery signal in a second portion of the subband of the shared frequency band. In some aspects, receiving synchronization communication includes receiving a synchronization signal block (SSB), which includes a physical broadcast channel (PBCH), a primary synchronization signal (PSS), and a secondary synchronization signal (SSS). For example, the SSB can be a sidelink SSB (S-SSB). In some aspects, the sidelink configuration module 708 can be configured to receive a PBCH carrying a primary information block (MIB). The MIB can have... Figure 5The structure of the MIB 500 shown is similar to or the same as that of the MIB. For example, the MIB may include a sidelink resource configuration that includes or indicates modulation and coding schemes, resource block (RB) allocations, transport block (TB) sizes, demodulation reference signal (DMRS) modes, and / or any other suitable parameters associated with the discovery signal. In some aspects, the sidelink configuration module 708 may be configured to receive a PBCH that includes an indication of the first RB of the discovery signal and the size of the discovery signal (e.g., in RBs). In some aspects, the sidelink configuration module 708 may be configured to receive an indication of the position and / or period of a reference signal carried in the discovery signal. Synchronization information may include any suitable parameters or information used to assist the first UE in detecting and decoding the discovery signal.

[0132] In some aspects, the sidelink configuration module 708 can also be configured to receive a discovery signal from a second sidelink UE in a first timeslot and in a second portion of a subband of a shared frequency band. The sidelink configuration module 708 can be configured to receive the discovery signal based on a waveform similar to or the same as that of PSSCH communication. Therefore, the sidelink configuration module 708 can be configured to detect or decode the discovery signal based on DMRS mode, MCS, RB allocation, TB size, and / or any other waveform parameters based on corresponding parameters of the PSSCH waveform. In some aspects, the information carried in the discovery signal can be similar to or the same as the Residual Minimal System Information (RMSI). The discovery signal can include or indicate one or more sidelink communication parameters. For example, the discovery signal can provide configuration information that can be used by multiple sidelink UEs for self-organizing and coordinating transmissions, using sidelink channel resources, detecting and synchronizing with other UEs, providing coordination or anchoring UEs, establishing resource pools, and / or any other sidelink functions.

[0133] In some aspects, receiving a discovery signal includes transmitting a Physical Shared Channel (PSSCH). For example, in some aspects, the PSSCH may be similar to or the same as the Physical Side Link Shared Channel (PSSCH). The PSSCH may differ from the PSSCH because control information (e.g., SCI) can be carried in the synchronization communication. For example, the MIB of the PBCH can carry control information, as explained above. In some aspects, the side link configuration module 708 may be configured to receive multiple repetitions of the discovery signal over a time period. For example, the side link configuration module 708 may be configured to receive multiple repetitions of the discovery signal at an 80ms interval or any other suitable interval. Therefore, the side link configuration module 708 may be configured to perform soft decoding of the discovery signal based on multiple repetitions.

[0134] As shown in the figure, transceiver 710 may include modem subsystem 712 and RF unit 714. Transceiver 710 may be configured to communicate bidirectionally with other devices (such as UE 115 and / or 700 and / or another core network element). Modem subsystem 712 may be configured to modulate and / or encode data according to MCS (e.g., LDPC coding scheme, turbo coding scheme, convolutional coding scheme, polarization coding scheme, digital beamforming scheme, etc.). RF unit 714 may be configured to process (e.g., perform analog-to-digital conversion or digital-to-analog conversion, etc.) modulated / coded data from modem subsystem 712 (in outward transmission) or from another source (such as UE 115 and / or UE 700). RF unit 714 can also be configured to perform analog beamforming in conjunction with digital beamforming. Although shown as being integrated into transceiver 710, modem subsystem 712 and / or RF unit 714 can be separate devices coupled together at UE 115 to enable UE 115 to communicate with other devices.

[0135] RF unit 714 can provide modulated and / or processed data, such as data packets (or more generally, data messages containing one or more data packets and other information), to antenna 716 for transmission to one or more other devices. RF unit 714 can process the modulated and / or processed data and generate a corresponding time-domain waveform using SC-FDMA modulation before transmission via antenna 716. Antenna 716 can also receive data messages transmitted from other devices and provide the received data messages for processing and / or demodulation at transceiver 710. Transceiver 710 can provide the demodulated and decoded data to sidelink configuration module 708 for processing. Antenna 716 may include multiple antennas with similar or different designs to maintain multiple transmission links.

[0136] In one aspect, the sidelink UE 700 may include multiple transceivers 710 implementing different RATs (e.g., NR and LTE). In another aspect, the sidelink UE 700 may include a single transceiver 710 implementing multiple RATs (e.g., NR and LTE). In yet another aspect, the transceiver 710 may include various components, wherein different combinations of the components can implement different RATs.

[0137] In some embodiments, the sidelink UE 700 may provide a discovery signal in the form of an RMSI. In some aspects, the RMSI includes additional system parameter information that differs from at least a portion of the system parameter information in the SL-MIB. In some aspects, the transceiver 710 may transmit the RMSI in one or more of a plurality of PSCCHs, and the transceiver 710 may also transmit sidelink data in at least one of a plurality of PSSCHs.

[0138] Figure 8 This is a flowchart of an anchor node discovery process according to some aspects of this disclosure. The aspects of process 800 can be performed by a computing device of a wireless communication device (e.g., a processor, processing circuitry, and / or other suitable components) or other suitable units for performing these steps. For example, a wireless communication device (such as UE 115, 215, 415, and / or 700) can utilize one or more components (such as processor 702, memory 704, sidelink configuration module 708, transceiver 710, modem 712, and one or more antennas 716) to perform the steps of process 800. As shown, process 800 includes a plurality of enumerated steps, but aspects of process 800 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.

[0139] At block 810, a first sidelink UE (e.g., UE 115j) transmits synchronization communication to a second sidelink UE in a first time slot and a first portion of a subband of the shared frequency band. The synchronization communication may indicate the location of a discovery signal in a second portion of the subband of the shared frequency band. In some aspects, transmitting synchronization communication includes transmitting a synchronization signal block (SSB) comprising a physical broadcast channel (PBCH), a primary synchronization signal (PSS), and a secondary synchronization signal (SSS). For example, the SSB may be a sidelink SSB (S-SSB). In some aspects, the first sidelink UE may transmit a PBCH carrying a primary information block (MIB). The MIB may have a... Figure 5The structure of the MIB 500 shown is similar to or the same as that of the MIB. For example, the MIB may include sidelink resource configurations that include or indicate modulation and coding schemes, resource block (RB) allocations, transport block (TB) sizes, demodulation reference signal (DMRS) modes, and / or any other suitable parameters associated with the discovery signal. In some aspects, the first sidelink UE transmits an indication in the PBCH of the first RB of the discovery signal and the size of the discovery signal (e.g., in RBs). In some aspects, the first sidelink UE may also indicate the position and / or period of the reference signal carried in the discovery signal. Synchronization information may include any suitable parameters or information used to assist the second sidelink UE in detecting and decoding the discovery signal.

[0140] The first portion of a subband may include one or more consecutive RBs within the subband. In some aspects, a subband may be described as a channel with a bandwidth of 20 MHz, 80 MHz, 10 MHz, or any other suitable bandwidth (larger or smaller). The bandwidth of the subband may also be described or defined in terms of RBs. For example, a subband may include 50 RBs, 100 RBs, or any other suitable number of RBs (larger or smaller). The first-side traveling link UE may transmit synchronization communication such that the synchronization communication occupies the first portion of multiple RBs in the subband. In one aspect, the first portion of the subband includes 11 RBs. In some aspects, at least one RB may be located at or near the edge of the subband (e.g., the lowest or highest frequency). For example, the first RB of the first portion of the subband may be the first RB of the subband. In other aspects, the first RB of the first portion may not be the first RB of the subband. For example, a subband may include one or more RBs on either side of the first portion of the subband, in which synchronization communication is transmitted in the first portion of the subband. In some cases, the first sidelink UE may utilize one or more components (such as processor 702, sidelink configuration module 708, transceiver 710, modem 712 and one or more antennas 716) to perform the actions of block 810.

[0141] At block 820, the first sidelink UE transmits a discovery signal to the second sidelink UE in the first time slot and in the second portion of a subband of the shared frequency band. The first sidelink UE may transmit the discovery signal such that it includes a waveform similar to or identical to that of the PSSCH communication. Accordingly, the first sidelink UE may generate or prepare the discovery signal based on appropriate parameters of the PSSCH waveform to include DMRS mode, MCS, RB allocation, TB size, and / or any other waveform parameters. In some aspects, the information carried in the discovery signal may be similar to or identical to the Residual Minimal System Information (RMSI). The discovery signal may include or indicate sidelink connection configuration information including one or more sidelink communication parameters. For example, the discovery signal may include or indicate at least one of the following: sidelink resource pool configuration, network service information associated with the first sidelink UE, and / or UE identification information associated with the first UE. Therefore, the sidelink connection configuration can provide configuration information that can be used by multiple sidelink UEs for self-organizing and coordinating transmission, using sidelink channel resources, detecting and synchronizing with other UEs, specifying coordinating or anchoring UEs, establishing resource pools and / or any other sidelink functions.

[0142] In some aspects, transmitting a discovery signal includes transmitting a physical shared channel (PSSCH). For example, in some aspects, the PSSCH may be similar to or the same as the Physical Side Link Shared Channel (PSSCH). In some aspects, the PSSCH transmitted by the first-side link UE may differ from the PSSCH because control information (e.g., SCI) may be carried in the synchronization communication. For example, the MIB of the PBCH may carry control information, as described above. In some aspects, the first-side link UE may transmit multiple repetitions of the discovery signal within a time period. For example, the first-side link UE may transmit multiple repetitions of the discovery signal at 80ms intervals or any other suitable interval. Therefore, the second-side link UE may perform soft decoding of the discovery signal based on multiple repetitions.

[0143] The second portion of a subband of the shared frequency band may include one or more RBs that form a portion of the subband different from the RBs used for transmitting synchronization communication. As explained above, the second portion of the subband may be contiguous with the first portion of the subband. For example, a first-side walkway UE may transmit a discovery signal in a second or more RBs contiguous with a first or more RBs used for transmitting synchronization communication. In some aspects, the number of RBs used by the first-side walkway UE for transmitting the discovery signal may depend on the subcarrier spacing of the shared frequency band. For example, if the shared frequency band is associated with a subcarrier spacing of 30 kHz, the first-side walkway UE may transmit a discovery signal in a contiguous group of 36 RBs and may transmit synchronization communication in a contiguous group of 11 RBs. In another example, if the shared frequency band is associated with a subcarrier spacing of 15 kHz, the first-side walkway UE may transmit a discovery signal in a contiguous group of 72 RBs. However, it should be understood that these values ​​are examples, and the first-side walkway UE may transmit the discovery side walkway signal in any suitable number of RBs.

[0144] Furthermore, as described above, the first-side traversal UE can transmit a discovery signal in a first timeslot, which is the same timeslot used for transmitting synchronization communication. In some aspects, the first-side traversal UE can transmit and the second-side traversal UE can receive the discovery signal in the same 13 OFDM symbols used for transmitting synchronization communication, where the 14th symbol is an idle symbol or a gap symbol. Therefore, the discovery signal and the synchronization communication can be aligned in the time domain.

[0145] In some aspects, the first sidelink UE transmits a discovery signal such that the discovery signal is quasi-co-located (QCL) with synchronization communication. Furthermore, in some aspects, the first sidelink UE can use an antenna port that is the same antenna portion used for transmitting synchronization communication to transmit the discovery signal. In some aspects, by transmitting a discovery signal such that the discovery signal is time-aligned with and QCLs the synchronization communication, and such that the discovery signal occupies the portion of the subband not occupied by synchronization communication (e.g., S-SSB), the first sidelink UE can efficiently utilize network resources to transmit sidelink configuration information for sidelink coordination. Moreover, transmitting the discovery signal in this manner can provide a flexible and inclusive discovery signaling scheme that can be used by equipment associated with various network service providers and equipment manufacturers. For example, in some aspects, method 800 can be used by a UE without a network subscription. In some cases, the first sidelink UE can utilize one or more components (such as processor 702, sidelink configuration module 708, transceiver 710, modem 712, and one or more antennas 716) to perform the actions of block 820.

[0146] Figure 9This is a flowchart of a sidelink communication process 900 according to some aspects of this disclosure. The aspects of process 900 can be performed by a computing device of a wireless communication device (e.g., a processor, processing circuitry, and / or other suitable components) or other suitable units for performing these steps. For example, a wireless communication device (such as UE 115, 215, and / or 700) can utilize one or more components (such as processor 702, memory 704, sidelink configuration module 708, transceiver 710, modem 712, and one or more antennas 716) to perform the steps of process 900. As shown, process 900 includes a plurality of enumerated steps, but aspects of process 900 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.

[0147] At block 910, a first sidelink UE (e.g., UE 115j) receives synchronization communication from a second sidelink UE in a first time slot and a first portion of a subband of the shared frequency band. The synchronization communication may indicate the location of a discovery signal in a second portion of the subband of the shared frequency band. In some aspects, receiving synchronization communication includes receiving a synchronization signal block (SSB) comprising a physical broadcast channel (PBCH), a primary synchronization signal (PSS), and a secondary synchronization signal (SSS). For example, the SSB may be a sidelink SSB (S-SSB). In some aspects, the first sidelink UE may receive a PBCH carrying a primary information block (MIB). The MIB may have a... Figure 5 The structure of the MIB 500 shown is similar to or the same as that of the MIB. For example, the MIB may include a sidelink resource configuration that includes or indicates modulation and coding schemes, resource block (RB) allocations, transport block (TB) sizes, demodulation reference signal (DMRS) modes, and / or any other suitable parameters associated with the discovery signal. In some aspects, the first sidelink UE receives a PBCH that includes an indication of the first RB of the discovery signal and the size of the discovery signal (e.g., in RBs). In some aspects, the first sidelink UE may also receive an indication of the position and / or period of a reference signal carried in the discovery signal. Synchronization information may include any suitable parameters or information used to assist the first UE in detecting and decoding the discovery signal.

[0148] The first portion of a subband may include one or more consecutive RBs within the subband. In some aspects, a subband may be described as a channel with a bandwidth of 20 MHz, 80 MHz, 10 MHz, or any other suitable bandwidth (larger or smaller). The bandwidth of the subband may also be described or defined in terms of RBs. For example, a subband may include 50 RBs, 100 RBs, or any other suitable number of RBs (larger or smaller). A first-side traveling link UE may receive synchronization communication in the first portion of a plurality of RBs within the subband. In one aspect, the first portion of the subband includes 11 RBs. In some aspects, at least one RB may be located at or near an edge of the subband (e.g., the lowest or highest frequency). For example, the first RB of the first portion of the subband may be the first RB of the subband. In other aspects, the first RB of the first portion may not be the first RB of the subband. For example, a subband may include one or more RBs on either side of the first portion of the subband, in which synchronization communication is transmitted. In some cases, the first sidelink UE may utilize one or more components (such as processor 702, sidelink configuration module 708, transceiver 710, modem 712 and one or more antennas 716) to perform the actions of block 910.

[0149] At box 920, the first sidelink UE receives a discovery signal from the second sidelink UE in the first time slot and in the second portion of a subband of the shared frequency band. The first sidelink UE may receive the discovery signal based on a waveform similar to or the same as that of PSSCH communication. Accordingly, the first sidelink UE may detect or decode the discovery signal based on DMRS mode, MCS, RB allocation, TB size, and / or any other waveform parameters based on corresponding parameters of the PSSCH waveform. In some aspects, the information carried in the discovery signal may be similar to or the same as the Residual Minimal System Information (RMSI). The discovery signal may include or indicate one or more sidelink communication parameters. For example, the discovery signal may provide configuration information that can be used by multiple sidelink UEs for self-organizing and coordinating transmissions, using sidelink channel resources, detecting and synchronizing with other UEs, providing coordination or anchoring UEs, establishing resource pools, and / or any other sidelink functions.

[0150] In some aspects, receiving a discovery signal involves transmitting a physical shared channel. For example, in some aspects, the physical shared channel may be similar to or the same as the physical side link shared channel (PSSCH). The physical shared channel received by the first-side link UE may differ from the PSSCH because control information (e.g., SCI) may be carried in the synchronization communication. For example, the MIB of the PBCH may carry control information, as explained above. In some aspects, the first-side link UE may receive multiple repetitions of the discovery signal within a time period. For example, the first-side link UE may receive multiple repetitions of the discovery signal at an 80ms interval or any other suitable interval. Therefore, the first-side link UE may perform soft decoding of the discovery signal based on multiple repetitions.

[0151] The second portion of a subband of the shared frequency band may include one or more RBs that form a portion of the subband different from the RBs used to transmit synchronization communication. As explained above, the second portion of the subband may be contiguous with the first portion of the subband. For example, a first-side walkway UE may receive a discovery signal in a second or more RBs contiguous with a first or more RBs carrying synchronization communication. In some aspects, the number of RBs carrying the discovery signal may depend on the subcarrier spacing of the shared frequency band. For example, if the shared frequency band is associated with a subcarrier spacing of 30 kHz, the first-side walkway UE may receive a discovery signal in a contiguous group of 36 RBs and may receive synchronization communication in different contiguous groups of 11 RBs. In another example, if the shared frequency band is associated with a subcarrier spacing of 15 kHz, the first-side walkway UE may receive a discovery signal in a contiguous group of 72 RBs. However, it should be understood that these values ​​are examples, and the first-side walkway UE may receive a discovery-side walkway signal in any suitable number of RBs.

[0152] Furthermore, as described above, the first-side traversal UE can receive the discovery signal in a first timeslot, which is the same timeslot in which the first-side traversal UE receives synchronization communication. In some aspects, the first-side traversal UE can receive the discovery signal in the same 13 OFDM symbols used for transmitting synchronization communication, where the 14th symbol is an idle symbol or gap symbol. Therefore, the discovery signal and synchronization communication can be aligned in the time domain.

[0153] In some aspects, the first sidelink UE receives the discovery signal based on a quasi-co-address (QCL) relationship with the synchronization communication. Furthermore, in some aspects, the first sidelink UE can use an antenna port that is the same antenna portion used for receiving the synchronization communication to receive the discovery signal. In some cases, the sidelink transmitting UE can utilize one or more components (such as processor 702, sidelink configuration module 708, transceiver 710, modem 712, and one or more antennas 716) to perform the actions of block 920.

[0154] Other aspects of this disclosure include the following:

[0155] 1. A method performed by a first user equipment (UE), the method comprising:

[0156] A synchronization communication is transmitted to a second UE in a first time slot and a first portion of a sub-band of the shared frequency band, wherein the synchronization communication indicates the location of a discovery signal in a second portion of the sub-band of the shared frequency band; and

[0157] The discovery signal is sent to the second UE in the first time slot and in the second part of the sub-band of the shared frequency band.

[0158] 2. The method according to Clause 1, wherein the discovery signal indicates side-link connection configuration information.

[0159] 3. The method according to Clause 2, wherein the sidelink connection configuration information indicates at least one of the following:

[0160] Sidelink resource pool configuration;

[0161] Network service information associated with the first UE; or

[0162] UE identification information associated with the first UE.

[0163] 4. The method according to any one of clauses 1-3, wherein the synchronization communication includes a side link-synchronization signal block (S-SSB).

[0164] 5. The method according to any one of clauses 1-4, wherein the synchronization communication indicates one or more control parameters associated with the discovery signal.

[0165] 6. The method according to Clause 5, wherein the one or more control parameters indicate at least one of the following:

[0166] The modulation and coding scheme (MCS) of the discovery signal;

[0167] Resource block (RB) allocation for the discovery signal;

[0168] The size of the transmission block (TB) of the discovery signal; or

[0169] The demodulation reference signal (DMRS) mode of the discovery signal.

[0170] 7. The method according to any one of clauses 1-6, wherein sending the discovery signal comprises: sending two or more repetitions of the discovery signal within a time period.

[0171] 8. The method according to any one of clauses 1-7, wherein sending the discovery signal comprises: sending the discovery signal based on the Physical Side Link Shared Channel (PSSCH) waveform.

[0172] 9. The method according to any one of clauses 1-8, wherein the second portion of the subband comprises a plurality of resource blocks (RBs), wherein the plurality of RBs are contiguous with the RBs of the synchronous communication.

[0173] 10. The method according to any one of clauses 1-9, wherein sending the discovery signal comprises: sending the discovery signal such that the discovery signal and the synchronization communication are quasi-co-located (QCL).

[0174] 11. A method performed by a first user equipment (UE), the method comprising:

[0175] Synchronization communication is received from a second UE in a first time slot and a first portion of a sub-band of the shared frequency band, wherein the synchronization communication indicates the location of a discovery signal in a second portion of the sub-band of the shared frequency band; and

[0176] The discovery signal is received from the second UE in the first time slot and in the second portion of the sub-band of the shared frequency band based on the synchronous communication.

[0177] 12. As described in Clause 11,

[0178] The discovery signal includes side link configuration information indicating at least one of the following:

[0179] Sidelink resource pool configuration;

[0180] Network service information associated with the second UE; or

[0181] UE identification information associated with the second UE.

[0182] 13. The method described in Clause 12 further includes:

[0183] The sidelink communication is sent to the second UE based on the sidelink configuration information.

[0184] 14. The method according to any one of clauses 12-13 further includes:

[0185] Based on the sidelink configuration information, the second UE sends uplink (UL) communication to the base station (BS).

[0186] 15. The method according to any one of Clauses 11-14,

[0187] The synchronous communication includes a Master Information Block (MIB).

[0188] The MIB indicates one or more control parameters associated with the detection signal, and

[0189] The receiving of the discovery signal includes receiving the discovery signal based on one or more control parameters.

[0190] 16. The method according to Clause 15, wherein the one or more control parameters indicate at least one of the following:

[0191] The modulation and coding scheme (MCS) of the discovery signal;

[0192] Resource block (RB) allocation for the discovery signal;

[0193] The size of the transmission block (TB) of the discovery signal; or

[0194] The demodulation reference signal (DMRS) mode of the discovery signal.

[0195] 17. The method according to any one of Clauses 11-16,

[0196] The receiving of the discovery signal includes: receiving two or more repetitions of the discovery signal within a time period, and

[0197] The method further includes decoding the discovery signal based on the two or more repetitions of the discovery signal.

[0198] 18. A first user equipment (UE), comprising:

[0199] transceiver; and

[0200] A processor communicating with the transceiver, wherein the processor is configured to cause the transceiver to perform the following operations:

[0201] A synchronization communication is transmitted to a second UE in a first time slot and a first portion of a sub-band of the shared frequency band, wherein the synchronization communication indicates the location of a discovery signal in a second portion of the sub-band of the shared frequency band; and

[0202] The discovery signal is sent to the second UE in the first time slot and in the second part of the sub-band of the shared frequency band.

[0203] 19. The first UE as described in Clause 18, wherein the discovery signal indicates side-link connection configuration information.

[0204] 20. The first UE as described in Clause 19, wherein the sidelink connection configuration information indicates at least one of the following:

[0205] Sidelink resource pool configuration;

[0206] Network service information associated with the first UE; or

[0207] UE identification information associated with the first UE.

[0208] 21. The first UE according to any one of clauses 18-20, wherein the synchronization communication includes a sidelink-synchronization signal block (S-SSB).

[0209] 22. The first UE according to any one of clauses 18-21, wherein the synchronization communication indicates one or more control parameters associated with the discovery signal.

[0210] 23. The first UE as described in Clause 22, wherein the one or more control parameters indicate at least one of the following:

[0211] The modulation and coding scheme (MCS) of the discovery signal;

[0212] Resource block (RB) allocation for the discovery signal;

[0213] The size of the transmission block (TB) of the discovery signal; or

[0214] The demodulation reference signal (DMRS) mode of the discovery signal.

[0215] 24. The first UE according to any one of clauses 18-23, wherein the processor is configured to cause the transceiver to transmit the discovery signal by: the processor being configured to cause the transceiver to transmit the discovery signal based on a physical side crosslink shared channel (PSSCH) waveform.

[0216] 25. The first UE according to any one of clauses 18-24, wherein the processor is configured to cause the transceiver to send the discovery signal, comprising: the processor being configured to cause the transceiver to send the discovery signal such that the discovery signal and the synchronization communication are quasi-co-addressable (QCL).

[0217] 26. A first user equipment (UE), comprising:

[0218] transceiver; and

[0219] A processor communicating with the transceiver, wherein the processor is configured to cause the transceiver to perform the following operations:

[0220] Synchronization communication is received from a second UE in a first time slot and a first portion of a sub-band of the shared frequency band, wherein the synchronization communication indicates the location of a discovery signal in a second portion of the sub-band of the shared frequency band; and

[0221] The discovery signal is received from the second UE in the first time slot and in the second portion of the sub-band of the shared frequency band based on the synchronous communication.

[0222] 27. The first UE as described in Clause 26,

[0223] The discovery signal includes side link configuration information indicating at least one of the following:

[0224] Sidelink resource pool configuration;

[0225] Network service information associated with the second UE; or

[0226] UE identification information associated with the second UE.

[0227] 28. The first UE as described in Clauses 26 and 27,

[0228] The synchronous communication includes a Master Information Block (MIB).

[0229] The MIB indicates one or more control parameters associated with the detection signal, and

[0230] The processor is configured to cause the transceiver to receive the discovery signal, wherein the processor is configured to cause the transceiver to receive the discovery signal based on the one or more control parameters.

[0231] 29. The first UE as described in Clause 28, wherein the one or more control parameters indicate at least one of the following:

[0232] The modulation and coding scheme (MCS) of the discovery signal;

[0233] Resource block (RB) allocation for the discovery signal;

[0234] The size of the transmission block (TB) of the discovery signal; or

[0235] The demodulation reference signal (DMRS) mode of the discovery signal.

[0236] 30. The first UE pursuant to any one of Clauses 26-30,

[0237] The processor is configured to cause the transceiver to receive the discovery signal, comprising: the processor being configured to cause the transceiver to receive two or more repetitions of the discovery signal within a time period; and

[0238] The processor is further configured to decode the discovery signal based on the two or more repetitions of the discovery signal.

[0239] 31. A non-transitory computer-readable medium having program code recorded thereon, wherein the program code comprises:

[0240] Code for causing a first user equipment (UE) to send synchronization communication to a second UE in a first time slot and a first portion of a subband of a shared frequency band, wherein the synchronization communication indicates the location of a discovery signal in a second portion of the subband of the shared frequency band; and

[0241] Code for causing the first UE to send the discovery signal to the second UE in the first time slot and in the second portion of the sub-band of the shared frequency band.

[0242] 32. The non-transitory computer-readable medium of claim 31, wherein the discovery signal indicates side-link connection configuration information.

[0243] 33. The non-transitory computer-readable medium of claim 32, wherein the sidelink connection configuration information indicates at least one of the following:

[0244] Sidelink resource pool configuration;

[0245] Network service information associated with the first UE; or

[0246] UE identification information associated with the first UE.

[0247] 34. The non-transitory computer-readable medium according to any one of claims 31-33, wherein the synchronization communication includes a side link-synchronization signal block (S-SSB).

[0248] 35. The non-transitory computer-readable medium according to any one of claims 31-34, wherein the synchronous communication indicates one or more control parameters associated with the discovery signal.

[0249] 36. The non-transitory computer-readable medium of claim 35, wherein the one or more control parameters indicate at least one of the following:

[0250] The modulation and coding scheme (MCS) of the discovery signal;

[0251] Resource block (RB) allocation for the discovery signal;

[0252] The size of the transmission block (TB) of the discovery signal; or

[0253] The demodulation reference signal (DMRS) mode of the discovery signal.

[0254] 37. The non-transitory computer-readable medium according to any one of claims 31-36, wherein the code for causing the first UE to send the discovery signal comprises: two or more repeated codes for causing the first UE to send the discovery signal within a time period.

[0255] 38. The non-transitory computer-readable medium according to any one of claims 31-37, wherein the code for causing the first UE to send the discovery signal comprises: code for causing the first UE to send the discovery signal based on a physical side link shared channel (PSSCH) waveform.

[0256] 39. The non-transitory computer-readable medium according to any one of claims 31-38, wherein the second portion of the subband comprises a plurality of resource blocks (RBs), wherein the plurality of RBs are contiguous with the RBs of the synchronous communication.

[0257] 40. The non-transitory computer-readable medium according to any one of claims 31-39, wherein the code for causing the first UE to send the discovery signal comprises: code for causing the first UE to send the discovery signal such that the discovery signal and the synchronization communication are quasi-co-addressable (QCL).

[0258] 41. A non-transitory computer-readable medium having program code recorded thereon, wherein the program code comprises:

[0259] Synchronization communication is received from a second UE in a first time slot and a first portion of a sub-band of the shared frequency band, wherein the synchronization communication indicates the location of a discovery signal in a second portion of the sub-band of the shared frequency band; and

[0260] The discovery signal is received from the second UE in the first time slot and in the second portion of the sub-band of the shared frequency band based on the synchronous communication.

[0261] 42. The non-transitory computer-readable medium according to claim 41,

[0262] The discovery signal includes side link configuration information indicating at least one of the following:

[0263] Sidelink resource pool configuration;

[0264] Network service information associated with the second UE; or

[0265] UE identification information associated with the second UE.

[0266] 43. The non-transitory computer-readable medium according to claim 42, further comprising:

[0267] The sidelink communication is sent to the second UE based on the sidelink configuration information.

[0268] 44. The non-transitory computer-readable medium according to any one of claims 42-43, wherein the program code further comprises:

[0269] Code used to enable the first UE to send uplink (UL) communication to the base station (BS) via the second UE based on the sidelink configuration information.

[0270] 45. The non-transitory computer-readable medium according to any one of claims 41-44,

[0271] The synchronous communication includes a Master Information Block (MIB).

[0272] The MIB indicates one or more control parameters associated with the detection signal, and

[0273] The code for causing the first UE to receive the discovery signal includes: code for causing the first UE to receive the discovery signal based on the one or more control parameters.

[0274] 46. ​​The non-transitory computer-readable medium of claim 45, wherein the one or more control parameters indicate at least one of the following:

[0275] The modulation and coding scheme (MCS) of the discovery signal;

[0276] Resource block (RB) allocation for the discovery signal;

[0277] The size of the transmission block (TB) of the discovery signal; or

[0278] The demodulation reference signal (DMRS) mode of the discovery signal.

[0279] 47. The non-transitory computer-readable medium according to any one of claims 41-46,

[0280] The code for causing the first UE to receive the discovery signal includes: two or more repeated codes for causing the first UE to receive the discovery signal within a time period, and

[0281] The program code further includes: code for causing the first UE to decode the discovery signal based on the two or more repetitions of the discovery signal.

[0282] 48. A first user equipment (UE), comprising:

[0283] A unit for transmitting synchronization communication to a second UE in a first time slot and a first portion of a sub-band of a shared frequency band, wherein the synchronization communication indicates the location of a discovery signal in a second portion of the sub-band of the shared frequency band; and

[0284] A unit for transmitting the discovery signal to the second UE in the first time slot and in the second portion of the sub-band of the shared frequency band.

[0285] 49. The first UE as described in Clause 48, wherein the discovery signal indicates side-link connection configuration information.

[0286] 50. The first UE as described in Clause 49, wherein the sidelink connection configuration information indicates at least one of the following:

[0287] Sidelink resource pool configuration;

[0288] Network service information associated with the first UE; or

[0289] UE identification information associated with the first UE.

[0290] 51. The first UE according to any one of clauses 48-50, wherein the synchronization communication includes a sidelink-synchronization signal block (S-SSB).

[0291] 52. The first UE according to any one of clauses 48-51, wherein the synchronization communication indicates one or more control parameters associated with the discovery signal.

[0292] 53. The first UE as described in Clause 52, wherein the one or more control parameters indicate at least one of the following:

[0293] The modulation and coding scheme (MCS) of the discovery signal;

[0294] Resource block (RB) allocation for the discovery signal;

[0295] The size of the transmission block (TB) of the discovery signal; or

[0296] The demodulation reference signal (DMRS) mode of the discovery signal.

[0297] 54. The first UE according to any one of clauses 48-53, wherein the unit for transmitting the discovery signal comprises: two or more repeating units for transmitting the discovery signal within a time period.

[0298] 55. The first UE according to any one of clauses 48-54, wherein the unit for transmitting the discovery signal comprises: a unit for transmitting the discovery signal based on the Physical Side Link Shared Channel (PSSCH) waveform.

[0299] 56. The first UE according to any one of clauses 48-55, wherein the second portion of the subband includes a plurality of resource blocks (RBs), wherein the plurality of RBs are contiguous with the RBs of the synchronous communication.

[0300] 57. The first UE according to any one of clauses 48-56, wherein the unit for transmitting the discovery signal comprises: a unit for transmitting the discovery signal such that the discovery signal and the synchronization communication are quasi-co-located (QCL).

[0301] 58. A first user equipment (UE), comprising:

[0302] A unit for receiving synchronization communication from a second UE in a first time slot and a first portion of a sub-band of a shared frequency band, wherein the synchronization communication indicates the location of a discovery signal in a second portion of the sub-band of the shared frequency band; and

[0303] A unit for receiving the discovery signal from the second UE in the first time slot and in the second portion of the sub-band of the shared frequency band based on the synchronous communication.

[0304] 59. The first UE as described in Clause 58,

[0305] The discovery signal includes side link configuration information indicating at least one of the following:

[0306] Sidelink resource pool configuration;

[0307] Network service information associated with the second UE; or

[0308] UE identification information associated with the second UE.

[0309] 60. The first UE as described in Clause 59 further includes:

[0310] A unit for sending sidelink communication to the second UE based on the sidelink configuration information.

[0311] 61. The first UE according to any one of clauses 59-60 further includes:

[0312] A unit for transmitting uplink (UL) communication to a base station (BS) via the second UE based on the sidelink configuration information.

[0313] 62. The first UE pursuant to any one of clauses 58-61,

[0314] The synchronous communication includes a Master Information Block (MIB).

[0315] The MIB indicates one or more control parameters associated with the detection signal, and

[0316] The unit for receiving the discovery signal includes a unit for receiving the discovery signal based on the one or more control parameters.

[0317] 63. The first UE as described in Clause 62, wherein the one or more control parameters indicate at least one of the following:

[0318] The modulation and coding scheme (MCS) of the discovery signal;

[0319] Resource block (RB) allocation for the discovery signal;

[0320] The size of the transmission block (TB) of the discovery signal; or

[0321] The demodulation reference signal (DMRS) mode of the discovery signal.

[0322] 64. The first UE pursuant to any one of clauses 58-63,

[0323] The unit for receiving the discovery signal includes: two or more repeating units for receiving the discovery signal within a time period, and

[0324] The method further includes a unit for decoding the discovery signal based on the two or more repetitions of the discovery signal.

[0325] Information and signals can 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 can be represented by voltage, current, electromagnetic waves, magnetic fields or particles, light fields or particles, or any combination thereof.

[0326] The various illustrative boxes and modules described in conjunction with the disclosure herein can be implemented or executed using a general-purpose processor, DSP, ASIC, FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware component or any combination thereof designed to perform the functions described herein. The general-purpose processor may be a microprocessor, but alternatively, 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, multiple microprocessors, one or more microprocessors combined with a DSP core, or any other such configuration).

[0327] The functions described herein can be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, these functions can be stored on or transmitted on a computer-readable medium as one or more instructions or code. Other examples and implementations are within the scope of this disclosure and the appended claims. For example, due to the nature of software, the functions described above can be implemented using software executed by a processor, hardware, firmware, hardwiring, or any combination thereof. Features used to implement the functions can also be physically located in various locations, including being distributed such that portions of the functions are implemented in different physical locations. Furthermore, as used herein (including in the claims), "or" as used in a list of items (e.g., a list of items ending with phrases such as "at least one of" or "one or more of") indicates an inclusive list, such 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).

[0328] As those skilled in the art will understand to date, and depending on the particular application at hand, numerous modifications may be made to the materials, apparatus, configuration, and methods of use of the devices described herein, without departing from the spirit and scope of this disclosure.

[0329] Modifications, substitutions, and variations. Therefore, the scope of this disclosure should not be limited to the specific embodiments shown and described herein (as they are only by way of some examples), but should be fully equivalent to the scope of the appended claims and their functional equivalents.

Claims

1. A method performed by a first user equipment (UE), the method comprising: A synchronization communication is sent to a second UE in a first time slot and a first portion of a subband of an unlicensed frequency band, wherein the synchronization communication indicates the location of a discovery signal in a second portion of the subband of the unlicensed frequency band, and wherein the synchronization communication includes a demodulation reference signal (DMRS) mode field, wherein the field includes a value for indicating a DMRS mode to be used by the second UE to decode the discovery signal, wherein the DMRS mode is associated with a physical side crosslink shared channel (PSSCH) waveform; The discovery signal is sent to the second UE in the first time slot and in the second portion of the sub-band of the unlicensed frequency band; In the second portion of the sub-band of the unlicensed frequency band, one or more repetitions of the discovery signal are transmitted to the second UE, wherein the one or more repetitions of transmitting the discovery signal are based on the DMRS mode; and Based on the discovery signal and one or more repetitions of the discovery signal, receive-side link communication is performed.

2. The method of claim 1, wherein, The discovery signal indicates the crosslink connection configuration information.

3. The method of claim 2, wherein, The sidelink connection configuration information indicates at least one of the following: Sidelink resource pool configuration; Network service information associated with the first UE; or UE identification information associated with the first UE.

4. The method of claim 1, wherein, The synchronization communication includes a side link-synchronization signal block (S-SSB).

5. The method according to claim 1, wherein, The synchronization communication indicates one or more control parameters associated with the discovery signal.

6. The method of claim 5, wherein, The one or more control parameters include values ​​indicating the DMRS mode to be used for decoding by the second UE, and wherein the one or more control parameters further indicate at least one of the following: The modulation and coding scheme (MCS) of the discovery signal; The resource block (RB) allocation for the discovery signal; or The size of the transmission block (TB) of the discovery signal.

7. The method of claim 1, wherein, Sending the discovery signal includes sending the discovery signal based on the physical side link shared channel (PSSCH) waveform and the repetition interval for soft decoding.

8. The method of claim 1, wherein, The second portion of the subband includes a plurality of resource blocks (RBs), wherein the plurality of RBs are contiguous with the RBs of the synchronous communication.

9. The method of claim 1, wherein, Sending the discovery signal includes sending the discovery signal such that the discovery signal and the synchronization communication are quasi-co-addressable (QCL).

10. A method performed by a first user equipment (UE), the method comprising: A synchronization communication is received from a second UE in a first time slot and a first portion of a subband of an unlicensed frequency band, wherein the synchronization communication indicates the location of a discovery signal in a second portion of the subband of the unlicensed frequency band, and wherein the synchronization communication includes a demodulation reference signal (DMRS) mode field, wherein the field includes a value for indicating a DMRS mode to be used by the second UE to decode the discovery signal, wherein the DMRS mode is associated with a physical side crosslink shared channel (PSSCH) waveform; The discovery signal is received from the second UE in the first time slot and in the second portion of the sub-band of the unlicensed frequency band based on the synchronous communication. In the second portion of the sub-band of the unlicensed frequency band, one or more repetitions of the discovery signal are received from the second UE, wherein the one or more repetitions of the discovery signal are associated with the DMRS mode; and Based on the discovery signal and one or more repetitions of the discovery signal, sidelink communication is sent.

11. The method according to claim 10, wherein, The discovery signal includes side link configuration information indicating at least one of the following: Sidelink resource pool configuration; Network service information associated with the second UE; or UE identification information associated with the second UE.

12. The method of claim 11, further comprising: The sidelink communication is sent to the second UE based on the sidelink configuration information.

13. The method of claim 11, further comprising: Based on the sidelink configuration information, the second UE sends uplink (UL) communication to the base station (BS).

14. The method according to claim 10, wherein The synchronization communication includes a Master Information Block (MIB). The MIB indicates one or more control parameters associated with the detection signal, and The receiving of the discovery signal includes receiving the discovery signal based on one or more control parameters.

15. The method of claim 14, wherein, The one or more control parameters include values ​​indicating the DMRS mode to be used for decoding by the second UE, and wherein the one or more control parameters further indicate at least one of the following: The modulation and coding scheme (MCS) of the discovery signal; The resource block (RB) allocation for the discovery signal; or The size of the transmission block (TB) of the discovery signal.

16. The method according to claim 10, wherein The method further includes: decoding the discovery signal based on the discovery signal and one or more repetitions of the discovery signal, wherein the one or more repetitions of the discovery signal are associated with a repetition interval for soft decoding.

17. A first user equipment (UE), comprising: transceiver; as well as A processor communicating with the transceiver, wherein the processor is configured to cause the transceiver to perform the following operations: A synchronization communication is sent to a second UE in a first time slot and a first portion of a subband of an unlicensed frequency band, wherein the synchronization communication indicates the location of a discovery signal in a second portion of the subband of the unlicensed frequency band, and wherein the synchronization communication includes a demodulation reference signal (DMRS) mode field, wherein the field includes a value for indicating a DMRS mode to be used by the second UE to decode the discovery signal, wherein the DMRS mode is associated with a physical side crosslink shared channel (PSSCH) waveform; The discovery signal is sent to the second UE in the first time slot and in the second portion of the sub-band of the unlicensed frequency band; In the second portion of the sub-band of the unlicensed frequency band, one or more repetitions of the discovery signal are transmitted to the second UE, wherein the one or more repetitions of transmitting the discovery signal are based on the DMRS mode; and Based on the discovery signal and one or more repetitions of the discovery signal, receive-side link communication is performed.

18. The first UE of claim 17, wherein, The discovery signal indicates the crosslink connection configuration information.

19. The first UE of claim 18, wherein, The sidelink connection configuration information indicates at least one of the following: Sidelink resource pool configuration; Network service information associated with the first UE; or UE identification information associated with the first UE.

20. The first UE of claim 17, wherein, The synchronization communication includes a side link-synchronization signal block (S-SSB).

21. The first UE of claim 17, wherein, The synchronization communication indicates one or more control parameters associated with the discovery signal.

22. The first UE of claim 21, wherein, The one or more control parameters include values ​​indicating the DMRS mode to be used for decoding by the second UE, and wherein the one or more control parameters further indicate at least one of the following: The modulation and coding scheme (MCS) of the discovery signal; The resource block (RB) allocation for the discovery signal; or The size of the transmission block (TB) of the discovery signal.

23. The first UE of claim 17, wherein, The processor is configured to cause the transceiver to send the discovery signal, including: the processor is configured to cause the transceiver to send the discovery signal based on the physical side link shared channel (PSSCH) waveform and the repetition interval for soft decoding.

24. The first UE of claim 17, wherein, The processor is configured to cause the transceiver to send the discovery signal, including: the processor is configured to cause the transceiver to send the discovery signal such that the discovery signal and the synchronization communication are quasi-co-addressable (QCL).

25. A first user equipment (UE), comprising: transceiver; as well as A processor communicating with the transceiver, wherein the processor is configured to cause the transceiver to perform the following operations: A synchronization communication is received from a second UE in a first time slot and a first portion of a subband of an unlicensed frequency band, wherein the synchronization communication indicates the location of a discovery signal in a second portion of the subband of the unlicensed frequency band, and wherein the synchronization communication includes a demodulation reference signal (DMRS) mode field, wherein the field includes a value for indicating a DMRS mode to be used by the second UE to decode the discovery signal, wherein the DMRS mode is associated with a physical side crosslink shared channel (PSSCH) waveform; The discovery signal is received from the second UE in the first time slot and in the second portion of the sub-band of the unlicensed frequency band based on the synchronous communication. In the second portion of the sub-band of the unlicensed frequency band, one or more repetitions of the discovery signal are received from the second UE, wherein the one or more repetitions of the discovery signal are associated with the DMRS mode; and Based on the discovery signal and one or more repetitions of the discovery signal, sidelink communication is sent.

26. The first UE according to claim 25, wherein, The discovery signal includes side link configuration information indicating at least one of the following: Sidelink resource pool configuration; Network service information associated with the second UE; or UE identification information associated with the second UE.

27. The first UE according to claim 25, wherein, The synchronization communication includes a Master Information Block (MIB). The MIB indicates one or more control parameters associated with the detection signal, and The processor is configured to cause the transceiver to receive the discovery signal, wherein the processor is configured to cause the transceiver to receive the discovery signal based on the one or more control parameters.

28. The first UE of claim 27, wherein, The one or more control parameters include values ​​indicating the DMRS mode to be used for decoding by the second UE, and wherein the one or more control parameters further indicate at least one of the following: The modulation and coding scheme (MCS) of the discovery signal; The resource block (RB) allocation for the discovery signal; or The size of the transmission block (TB) of the discovery signal.

29. The first UE according to claim 25, wherein The processor is further configured to decode the discovery signal based on the discovery signal and one or more repetitions of the discovery signal, wherein the one or more repetitions of the discovery signal are associated with a repetition interval for soft decoding.

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