Discovery indication for sidelink

Abstract

Aspects presented herein can improve sidelink discovery procedures for resource efficiency and / or power saving, where power consumption at a receiving sidelink device and / or a transmitting sidelink device can be reduced when the receiving sidelink device and / or the transmitting sidelink device is performing a sidelink discovery procedure. In one aspect, an apparatus transmits an indication to a second wireless device, the indication indicating, in physical layer signaling, whether a PSSCH carries a discovery message. The apparatus transmits the PSSCH (e.g., including a discovery message or a communication message) based at least in part on the indication.

Description

[0001] Cross-reference to related applications

[0002] This application claims the benefit of U.S. Patent Application No. 16 / 951,911, filed November 18, 2020, entitled “DISCOVERY INDICATION FORSIDELINK,” the entire contents of which are expressly incorporated herein by reference. Technical Field

[0003] This disclosure generally relates to communication systems, and more specifically, to sidelink communication. Background Technology

[0004] Wireless communication systems are widely deployed to provide a variety of telecommunications services, such as telephone, video, data, information transmission, and broadcasting. Typical wireless communication systems employ multiple access technologies, enabling communication with multiple users by sharing available system resources. Examples of such multiple access technologies include Code Division Multiple Access (CDMA) systems, Time Division Multiple Access (TDMA) systems, Frequency Division Multiple Access (FDMA) systems, Orthogonal Frequency Division Multiple Access (OFDMA) systems, Single Carrier Frequency Division Multiple Access (SC-FDMA) systems, and Time Division Synchronous Code Division Multiple Access (TD-SCDMA) systems.

[0005] These multiple access technologies have been adopted by various telecommunications standards to provide a common protocol enabling different wireless devices to communicate at the city, national, regional, and even global levels. One example of a telecommunications standard is 5G New Radio (NR). 5G NR is part of the Continuous Evolution of Mobile Broadband (CWB) program issued by the 3rd Generation Partnership Project (3GPP) to meet new requirements associated with latency, reliability, security, scalability (e.g., with the Internet of Things (IoT)), and other requirements. 5G NR includes services associated with enhanced mobile broadband (eMBB), massive machine-type communications (mMTC), and ultra-reliable low-latency communications (URLLC). Some aspects of 5G NR can be based on the 4G Long Term Evolution (LTE) standard. Some aspects of wireless communication can include direct communication between devices based on sidelinks, such as in vehicle-to-everything (V2X) and / or other device-to-device (D2D) communications. There is a need for further improvements to sidelink technologies. These improvements can also be applied to other multiple access technologies and telecommunications standards that adopt these technologies. Summary of the Invention

[0006] The following is a simplified overview of one or more aspects to provide a basic understanding of them. This overview is not a broad summary of all conceived aspects, nor is it intended to identify key or important elements of all aspects, nor to define the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed descriptions that follow.

[0007] In one aspect of this disclosure, an apparatus for wireless communication is provided. The apparatus includes a memory and at least one processor coupled to the memory, the memory and at least one processor being configured to: transmit an indication to a second wireless device, the indication indicating in physical layer signaling whether a physical-side crosslink shared channel (PSSCH) carries a discovery message; and transmit the PSSCH at least in part based on the indication.

[0008] In another aspect of this disclosure, a method for wireless communication at a first wireless device is provided. The method includes: sending an indication to a second wireless device, the indication indicating in physical layer signaling whether a PSSCH carries a discovery message; and sending a PSSCH at least in part based on the indication.

[0009] In another aspect of this disclosure, an apparatus for wireless communication is provided. The apparatus includes a unit for transmitting an indication to a second wireless device, the indication indicating in physical layer signaling whether a PSSCH carries a discovery message; and a unit for transmitting a PSSCH at least in part based on the indication.

[0010] In another aspect of this disclosure, a computer-readable storage medium is provided for wireless communication at a first wireless device. The computer-readable storage medium may, for example, be non-transitory. The computer-readable storage medium includes code for: sending an indication to a second wireless device that indicates in physical layer signaling whether a PSSCH carries a discovery message; and sending a PSSCH at least in part based on the indication.

[0011] In one aspect of this disclosure, an apparatus for wireless communication is provided. The apparatus includes a memory and at least one processor coupled to the memory, the memory and at least one processor being configured to: receive an indication from a second wireless device indicating in physical layer signaling whether a PSSCH carries a discovery message; determine whether the PSSCH carries a discovery message; and if the indication indicates that the PSSCH carries a discovery message, decode the discovery message in the PSSCH.

[0012] In another aspect of this disclosure, a method for wireless communication at a first wireless device is provided. The method includes: monitoring an indication from a second wireless device indicating in physical layer signaling whether a PSSCH carries a discovery message; determining whether the PSSCH carries a discovery message; and if the indication indicates that the PSSCH carries a discovery message, decoding the discovery message in the PSSCH.

[0013] In another aspect of this disclosure, an apparatus for wireless communication is provided. The apparatus includes: a unit for monitoring an indication from a second wireless device, the indication indicating in physical layer signaling whether a PSSCH carries a discovery message; a unit for determining whether the PSSCH carries a discovery message; and a unit for decoding the discovery message in the PSSCH if the indication indicates that the PSSCH carries a discovery message.

[0014] In another aspect of this disclosure, a computer-readable storage medium is provided for wireless communication at a first wireless device. The computer-readable storage medium may, for example, be non-transitory. The computer-readable storage medium includes code for: monitoring an indication from a second wireless device that indicates in physical layer signaling whether a PSSCH carries a discovery message; determining whether the PSSCH carries a discovery message; and if the indication indicates that the PSSCH carries a discovery message, decoding the discovery message in the PSSCH.

[0015] To achieve the foregoing and related objectives, one or more aspects include the features fully described below and particularly indicated in the claims. The following description and the accompanying drawings set forth certain illustrative features of one or more aspects in detail. However, these features are merely indications of several ways in which the principles of the aspects may be employed, and this description is intended to encompass all such aspects and their equivalents. Attached Figure Description

[0016] Figure 1 This is a diagram illustrating an example of a wireless communication system and access network.

[0017] Figure 2 An example aspect of the side link time slot structure is illustrated.

[0018] Figure 3 This is a diagram illustrating an example of a first and a second device involved in wireless communication based on, for example, a side link.

[0019] Figure 4 This illustrates an example side-link communication system.

[0020] Figure 5 This is a diagram illustrating an example of wireless relay in a cellular network.

[0021] Figure 6An example of sensing-based resource allocation is illustrated.

[0022] Figure 7A and Figure 7B This is a communication flow that illustrates an example of lateral link discovery.

[0023] Figure 8 This is a diagram illustrating an example of a two-stage PSCCH.

[0024] Figure 9 This is a diagram illustrating an exemplary PSFCH configuration.

[0025] Figure 10 This is a diagram illustrating an example of a sidelink resource pool and a sidelink time slot structure.

[0026] Figure 11 This is a diagram illustrating exemplary findings indicated according to aspects of this disclosure.

[0027] Figure 12 This is a diagram illustrating exemplary findings indicated according to aspects of this disclosure.

[0028] Figure 13 This is a diagram illustrating exemplary findings indicated according to aspects of this disclosure.

[0029] Figure 14 This is a diagram illustrating exemplary findings indicated according to aspects of this disclosure.

[0030] Figure 15 This is a flowchart of a wireless communication method.

[0031] Figure 16 This is a diagram illustrating an example of the hardware implementation for the example device.

[0032] Figure 17 This is a flowchart of a wireless communication method.

[0033] Figure 18 This is a diagram illustrating an example of the hardware implementation for the example device. Detailed Implementation

[0034] The detailed description that follows, taken in conjunction with the accompanying drawings, is intended as a description of various configurations and not as representing the only configuration in which the concepts described herein can be implemented. The detailed description includes specific details intended to provide a thorough understanding of the various concepts. However, it will be apparent to those skilled in the art that these concepts can be implemented without these specific details. In some cases, well-known structures and components are shown in block diagram form to avoid obscuring these concepts.

[0035] Several aspects of a telecommunications system will now be presented with reference to various apparatuses and methods. These apparatuses and methods will be described in detail below and illustrated in the accompanying drawings by various blocks, components, circuits, processes, algorithms, etc. (collectively, “elements”). These elements can be implemented using electronic hardware, computer software, or any combination thereof. Whether these elements are implemented in hardware or software depends on the specific application and the design constraints imposed on the overall system.

[0036] For example, an element, any part of an element, or any combination of elements can be implemented as a “processing system” including one or more processors. Examples of processors include microprocessors, microcontrollers, graphics processing units (GPUs), central processing units (CPUs), application processors, digital signal processors (DSPs), simplified instruction set computing (RISC) processors, system-on-a-chip (SoCs), baseband processors, field-programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functions described throughout this disclosure. One or more processors in a processing system can execute software. Whether referred to as software, firmware, middleware, microcode, hardware description languages, or otherwise, software should be understood broadly as representing instructions, instruction sets, code, code segments, program code, programs, subroutines, software components, applications, software applications, software packages, routines, subroutines, objects, executable files, threads of execution, programs, functions, etc.

[0037] Therefore, in one or more examples, the functionality can be implemented in hardware, software, or any combination thereof. If implemented in software, the functionality can be stored on or encoded as one or more instructions or code on a computer-readable storage medium. Computer-readable media include computer storage media. Storage media can be any available medium accessible to a computer. By way of example, and not limitation, such computer-readable media can include random access memory (RAM), read-only memory (ROM), electrically erasable programmable ROM (EEPROM), optical disc storage, magnetic disk storage, other magnetic storage devices, combinations of computer-readable media of the types described above, or any other medium that can be used to store computer-executable code in the form of instructions or data structures accessible to a computer.

[0038] Sidelink communication can include direct wireless communication between a first device (e.g., a first UE or other sidelink device) and a second device (e.g., a second UE or other sidelink device), for example, without routing through a base station. In a first mode, the UE can receive resource allocation for sidelink communication from the base station. Sidelink resource allocation from the base station can be referred to as "resource allocation mode 1" or a "centralized" resource allocation mode, for example, where a network entity allocates sidelink resources for multiple sidelink devices. In a second mode, the UE can autonomously determine resources for sidelink transmission by sensing reservations made by other sidelink devices. Autonomous resource selection can be referred to as "resource allocation mode 2," a "distributed" resource allocation mode, or a sensing-based sidelink resource allocation mode, for example, where each sidelink device selects its own sidelink resources for sidelink transmission. Therefore, in resource allocation mode 2 (e.g., sensing-based sidelink resource allocation), the wireless device does not receive allocations for sidelink resources (e.g., as in resource allocation mode 1), but determines sidelink transmission resources based on sensing and resource reservation processes, for example, combining... Figure 6 As described. For example, a UE can perform sensing by monitoring an SCI that indicates other UEs are using or reserving resources for transmitting sidelink transmissions. An SCI indicating resources can be described as reserving sidelink resources. The indicated resources can be referred to as sidelink resource reservations. To exchange sidelink communication, the sidelink device can perform a discovery process, such as combining... Figure 7A and Figure 7B As described. The discovery process may include monitoring discovery signals from another sidelink device. For example, in one type of sidelink discovery model, a first UE (e.g., the UE making the announcement) may broadcast / multicast a discovery message to other UEs indicating its presence as a sidelink device. In response, other UEs that receive the discovery message may send a connection request message to the first UE to establish sidelink communication with the first UE. In another type of sidelink discovery model, the first UE (e.g., the discoverer UE) may broadcast a solicitation message to other UEs. In response, other UEs that receive the solicitation message may process the request and send a response message to the first UE. Monitoring discovery signals and / or sidelink reservation messages may consume power at the sidelink device.

[0039] The aspects proposed in this paper help the receiving UE improve power efficiency while continuing to enable the UE to discover other sideline devices and monitor sideline communications. For example, a transmitting sideline device can send an indication to one or more receiving sideline devices to indicate whether the PSSCH carries a discovery message and / or a communication message. The transmitting sideline device can then send the discovery message and / or communication message in the PSSCH based at least in part on the indication. The receiving sideline device can monitor the indication from the transmitting sideline device to determine whether the PSSCH carries a discovery message or a communication message. If the receiving sideline device detects / receives an indication that the PSSCH carries a discovery message, it can monitor the discovery message in that PSSCH. On the other hand, if the receiving sideline device detects / receives an indication that the PSSCH does not carry a discovery message, it can exclude or skip monitoring the discovery message in that PSSCH to reduce power consumption.

[0040] On the other hand, the transmitting UE can indicate to the receiving UE in physical layer signaling whether the PSSCH carries a discovery message and / or a communication message. In response, when the PSSCH carries a discovery message, the receiving UE can monitor or decode the PSSCH; when the PSSCH does not carry a discovery message, the receiving UE can skip decoding the PSSCH to reduce power consumption. Similarly, in response to a discovery message, the receiving UE can also indicate to the transmitting UE whether the PSSCH carries a discovery-related message. This indication can be provided in the first part (e.g., SCI-1) or the second part (e.g., SCI-2) of the side-link control information (SCI). The indication can be provided in the bits of the SCI, for example, in reserved bits or a new SCI format. The indication can be based on demodulation reference signal (DMRS) resource mapping or physical side-link shared channel (PSSCH) resource mapping. This indication can be provided in a new physical channel, which may be called the Physical Side Link Discovery Indication Channel, or by another name, identifying the physical channel configured to carry information about whether the PSSCH will carry a side link discovery message. This indication can be provided using Physical Side Link Feedback Channel (PSFCH) resources. The indication can specify the type of discovery message (e.g., an announcement message or a solicitation message) to be carried in the PSSCH. The aspects proposed herein enable discovery messages to be sent using the same side link resource pool as communication messages, thereby optimizing resource efficiency.

[0041] Figure 1This is a diagram illustrating an example of a wireless communication system and access network 100. UE 104 may include a sidelink discovery component 198 configured to send a discovery indication to other sidelink devices to indicate in physical layer signaling whether the PSSCH and / or PSCCH carries a discovery message and / or a communication message. When UE 104 receives or detects a discovery indication from another sidelink device / UE, the sidelink discovery component 198 may also determine whether to monitor or decode the PSSCH based on whether the PSSCH will contain a discovery message or a communication message. In one aspect, the sidelink discovery component 198 may be configured to send an indication to a second radio device indicating in physical layer signaling whether the PSSCH carries a discovery message. The sidelink discovery component 198 may be configured to send the PSSCH (e.g., including a discovery message or a communication message) at least in part based on this indication. In another aspect, the sidelink discovery component 198 may be configured to receive an indication from the second radio device indicating in physical layer signaling whether the PSSCH carries a discovery message. The sidelink discovery component 198 can be configured to determine whether the PSSCH carries a discovery message. The sidelink discovery component 198 can be configured to decode the discovery message in the PSSCH if the indication indicates that the PSSCH carries a discovery message.

[0042] The wireless communication system (also known as a wireless wide area network (WWAN)) includes base station 102, UE 104, evolved packet core (EPC) 160, and another core network 190 (e.g., a 5G core (5GC)). Base station 102 may include macro cells (high-power cellular base stations) and / or small cells (low-power cellular base stations). Macro cells include base stations. Small cells include femtocells, picocells, and microcells.

[0043] The link between UE 104 and base station 102 or 180 can be established as an access link, for example, using the Uu interface. Other communications can be exchanged between wireless devices based on sidelinks. For example, some UEs 104 can communicate directly with each other using device-to-device (D2D) communication link 158. In some examples, D2D communication link 158 can use DL / ULWWAN spectrum. D2D communication link 158 can use one or more sidelink channels, such as the Physical Sidelink Broadcast Channel (PSBCH), Physical Sidelink Discovery Channel (PSDCH), Physical Sidelink Shared Channel (PSSCH), and Physical Sidelink Control Channel (PSCCH). D2D communication can be conducted through various wireless D2D communication systems, such as WiMedia, Bluetooth, ZigBee, Wi-Fi based on the IEEE 802.11 standard, LTE, or NR.

[0044] Examples of sidelink communication can include vehicle-based communication devices that can communicate from vehicle to vehicle (V2V), vehicle to infrastructure (V2I) (e.g., from a vehicle-based communication device to a road infrastructure node, such as a roadside unit (RSU)), vehicle to network (V2N) (e.g., from a vehicle-based communication device to one or more network nodes such as a base station), vehicle to pedestrian (V2P), cellular vehicle to everything (C-V2X), and / or combinations thereof and / or with other devices; this can be collectively referred to as vehicle-to-everything (V2X) communication. Sidelink communication can be based on V2X or other D2D communication, such as proximity service (ProSe). Besides the UE, sidelink communication can also be transmitted and received by other transmitting and receiving devices such as the roadside unit (RSU) 107. Sidelink communication can be exchanged using the PC5 interface, for example, in combination with... Figure 2 The examples described herein. Although the following descriptions (including Figure 2 The example time slot structure can provide an example of side link communication combined with 5G NR, but the concepts described herein are applicable to other similar fields, such as LTE, LTE-A, CDMA, GSM and other wireless technologies.

[0045] Base station 102 configured for 4G LTE (collectively referred to as Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN)) can interface with EPC 160 via a first backhaul link 132 (e.g., S1 interface). Base station 102 configured for 5G NR (collectively referred to as Next Generation RAN (NG-RAN)) can interface with core network 190 via a second backhaul link 184. Among other functions, base station 102 can perform one or more of the following functions: transmission of user data, radio channel encryption and decryption, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity), inter-cell interference coordination, connection establishment and release, load balancing, distribution of non-access stratum (NAS) messages, NAS node selection, synchronization, radio access network (RAN) sharing, multimedia broadcast multicast service (MBMS), user and equipment tracking, RAN information management (RIM), paging, location, and warning message delivery. Base station 102 can communicate with each other directly or indirectly (e.g., via EPC 160 or core network 190) via third backhaul link 134 (e.g., X2 interface). First backhaul link 132, second backhaul link 184 and third backhaul link 134 can be wired or wireless.

[0046] Base station 102 can wirelessly communicate with UE 104. Each base station 102 can provide communication coverage for its respective geographic coverage area 110. There may be overlapping geographic coverage areas 110. For example, a small cell 102' may have a coverage area 110' that overlaps with the coverage areas 110 of one or more macro base stations 102. A network that includes both small cells and macro cells can be referred to as a heterogeneous network. A heterogeneous network may also include a Home Evolution Node B (eNB) (HeNB), which can provide services to a restricted group referred to as a Closed Subscriber Group (CSG). The communication link 120 between base station 102 and UE 104 may include uplink (UL) (also referred to as reverse link) transmission from UE 104 to base station 102 and / or downlink (DL) (also referred to as forward link) transmission from base station 102 to UE 104. The communication link 120 may use multiple-input multiple-output (MIMO) antenna technologies, including spatial multiplexing, beamforming, and / or transmit diversity. The communication link may carry one or more carriers. Base station 102 / UE 104 may use spectrum with a bandwidth of up to Y MHz per carrier (e.g., 5, 10, 15, 20, 100, 400 MHz, etc.), said carriers being allocated in carrier aggregation of up to a total of Yx MHz (x component carriers) for transmission in each direction. These carriers may or may not be adjacent to each other. The allocation of carriers may be asymmetric for DL ​​and UL (e.g., more or fewer carriers may be allocated to DL compared to UL). Component carriers may include primary component carriers and one or more secondary component carriers. The primary component carrier may be referred to as the primary cell (PCell), while the secondary component carrier may be referred to as the secondary cell (SCell).

[0047] The wireless communication system may further include a Wi-Fi access point (AP) 150 that communicates with a Wi-Fi station (STA) 152 via a communication link 154, for example in a 5 GHz unlicensed spectrum or similar spectrum. When communicating in unlicensed spectrum, the STA 152 / AP 150 may perform a free channel assessment (CCA) before communication to determine whether the channel is available.

[0048] Small cell 102' can operate in licensed and / or unlicensed spectrum. When operating in unlicensed spectrum, small cell 102' can employ NR and use the same unlicensed spectrum (e.g., 5 GHz, etc.) as Wi-Fi AP 150. Small cell 102' (using NR in unlicensed spectrum) can improve coverage of the access network and / or increase the capacity of the access network.

[0049] The electromagnetic spectrum is typically subdivided into various classes, bands, channels, etc., based on frequency / wavelength. In 5G NR, two initial operating frequency bands have been designated as frequency range names FR1 (410MHz-7.125GHz) and FR2 (24.25GHz-52.6GHz). The frequencies between FR1 and FR2 are generally referred to as the mid-band frequencies. Although a portion of FR1 is greater than 6GHz, FR1 is often referred to (interchangeably) as the "sub-6GHz" band in various documents and articles. Similar naming issues sometimes arise regarding FR2, which is often referred to (interchangeably) as the "millimeter wave" band in documents and articles, but this is different from the extremely high frequency (EHF) band (30GHz-300GHz) designated as "millimeter wave" by the International Telecommunication Union (ITU).

[0050] In light of the foregoing, unless otherwise specifically stated, the term "sub-6GHz" or similar terms (if used herein) should be understood to broadly represent frequencies that may be below 6GHz, within FR1, or may include intermediate frequency band frequencies. Furthermore, unless otherwise specifically stated, the term "millimeter wave" or similar terms (if used herein) should be understood to broadly represent frequencies that may include intermediate frequency band frequencies, within FR2, or within the EHF band.

[0051] Base station 102, whether a small cell 102' or a large cell (e.g., a macro base station), may include and / or be referred to as an eNB, g-node B (gNB), or other types of base station. Some base stations, such as gNB 180, may operate in the conventional sub-6 GHz spectrum, at millimeter-wave frequencies, and / or near-millimeter-wave frequencies to communicate with UE 104. When gNB 180 operates at millimeter-wave or near-millimeter-wave frequencies, gNB 180 may be referred to as a millimeter-wave base station. Millimeter-wave base station 180 may utilize beamforming 182 with UE 104 to compensate for path loss and short range. Base station 180 and UE 104 may each include multiple antennas, such as antenna elements, antenna panels, and / or antenna arrays, to facilitate beamforming. Similarly, beamforming can be applied to sidelink communications, for example, between UEs.

[0052] Base station 180 may transmit beamforming signals to UE 104 in one or more transmit directions 182'. UE 104 may receive beamforming signals from base station 180 in one or more receive directions 182'. UE 104 may also transmit beamforming signals to base station 180 in one or more transmit directions. Base station 180 may receive beamforming signals from UE 104 in one or more receive directions. Base station 180 / UE 104 may perform beam training to determine the optimal receive and transmit directions for each base station 180 / UE 104. The transmit and receive directions of base station 180 may be the same or different. The transmit and receive directions of UE 104 may be the same or different. Although this example is described with respect to base station 180 and UE 104, these aspects can be similarly applied to sidelink communication between first and second devices (e.g., first and second UEs).

[0053] EPC 160 may include Mobility Management Entity (MME) 162, other MMEs 164, Serving Gateway 166, Multimedia Broadcast Multicast Service (MBMS) Gateway 168, Broadcast Multicast Service Center (BM-SC) 170, and Packet Data Network (PDN) Gateway 172. MME 162 can communicate with Home Subscriber Server (HSS) 174. MME 162 is the control node that handles signaling between UE 104 and EPC 160. Generally, MME 162 provides bearer and connection management. All user Internet Protocol (IP) packets are transmitted through Serving Gateway 166, which is itself connected to PDN Gateway 172. PDN Gateway 172 provides UE IP address allocation and other functions. PDN Gateway 172 and BM-SC 170 are connected to IP Service 176. IP Service 176 may include the Internet, intranet, IP Multimedia Subsystem (IMS), PS streaming service, and / or other IP services. BM-SC 170 can provide provisioning and delivery functions for MBMS user services. The BM-SC 170 can serve as an entry point for MBMS transmission by content providers, can be used to authorize and initiate MBMS bearer services within a Public Land Mobile Network (PLMN), and can be used to schedule MBMS transmissions. The MBMS gateway 168 can be used to allocate MBMS services to base station 102 belonging to a Broadcast Specific Service Single Frequency Network (MBSFN) area, and can be responsible for session management (start / stop) and collection of eMBMS-related billing information.

[0054] Core network 190 may include Access and Mobility Management Function (AMF) 192, other AMFs 193, Session Management Function (SMF) 194, and User Plane Function (UPF) 195. AMF 192 can communicate with Unified Data Management (UDM) 196. AMF 192 is the control node that handles signaling between UE 104 and core network 190. Generally, AMF 192 provides QoS flow and session management. All user Internet Protocol (IP) packets are sent through UPF 195. UPF 195 provides UE IP address allocation and other functions. UPF 195 connects to IP service 197. IP service 197 may include the Internet, intranet, IP Multimedia Subsystem (IMS), Packet Switched (PS) Streaming (PSS) service, and / or other IP services.

[0055] Base stations may include and / or be referred to as gNB, Node B, eNB, access point, basic transceiver station, radio base station, radio transceiver, transceiver function, basic service set (BSS), extended service set (ESS), transmit / receive point (TRP), or some other suitable term. Base station 102 provides UE 104 with access to EPC 160 or core network 190. Examples of UE 104 include cellular phones, smartphones, Session Initiation Protocol (SIP) phones, laptops, personal digital assistants (PDAs), satellite radios, GPS devices, multimedia devices, video devices, digital audio players (e.g., MP3 players), cameras, game controllers, tablets, smart devices, wearable devices, vehicles, electricity meters, gas pumps, large or small kitchen appliances, healthcare devices, implants, sensors / actuators, displays, or any other similarly functional devices. Some UE 104 may be referred to as IoT devices (e.g., parking meters, gas pumps, toasters, vehicles, heart monitors, etc.). UE 104 can also be referred to as a station, mobile station, user station, mobile unit, user unit, radio unit, remote unit, mobile device, radio device, wireless communication device, remote device, mobile user station, access terminal, mobile terminal, radio terminal, remote terminal, mobile phone, user agent, mobile client, client, or some other suitable terminology.

[0056] Figure 2 The illustrations in diagrams 200 and 210 illustrate example aspects of the time slot structure for sidelink communication (e.g., between UE 104, RSU 107, etc.). In some examples, the time slot structure can be within a 5G / NR frame structure. In other examples, the time slot structure can be within an LTE frame structure. Although the description below may focus on 5G NR, the concepts described herein are applicable to other similar domains such as LTE, LTE-A, CDMA, GSM, and other wireless technologies.Figure 2 The exemplary time slot structure shown is just one example; other sidelink communications may have different frame structures and / or different channels for sidelink communication. A frame (10 ms) can be divided into 10 equally sized subframes (1 ms). Each subframe may include one or more time slots. Subframes may also include mini-time slots, which may include 7, 4, or 2 symbols. Each time slot may include 7 or 14 symbols, depending on the time slot configuration. For time slot configuration 0, each time slot may include 14 symbols, while for time slot configuration 1, each time slot may include 7 symbols. Schematic 200 illustrates a single resource block for single-time slot transmission, which may correspond to a transmission time interval (TTI) of 0.5 ms. The physical sidelink control channel can be configured to occupy multiple physical resource blocks (PRBs), for example, 10, 12, 15, 20, or 25 PRBs. The PSCCH can be limited to a single subchannel. For example, the PSCCH duration can be configured to 2 or 3 symbols. For example, subchannels may include 10, 15, 20, 25, 50, 75, or 100 PRBs. Resources used for lateral link transmissions can be selected from a resource pool that includes one or more subchannels. As a non-limiting example, the resource pool may include subchannels between 1 and 27. The PSCCH size can be established for the resource pool, for example, between 10% and 100% of a subchannel, with a duration of 2 or 3 symbols. Figure 2 Schematic diagram 210 illustrates an example where the PSCCH occupies approximately 50% of a subchannel, serving as an example to illustrate the concept of the PSCCH occupying a portion of a subchannel. The Physical Side Link Shared Channel (PSSCH) occupies at least one subchannel. In some examples, the PSCCH may include a first portion of the Side Link Control Information (SCI), and the PSSCH may include a second portion of the SCI.

[0057] A resource grid can be used to represent the frame structure. Each time slot can include a resource block (RB) (also known as a physical RB (PRB)) that extends for 12 consecutive subcarriers. The resource grid is divided into multiple resource elements (REs). The number of bits carried by each RE depends on the modulation scheme. Figure 2 As described herein, some REs may include control information from the PSCCH, and some REs may include demodulation RS (DMRS). At least one symbol may be used for feedback. Figure 2An example of two symbols for a Physical Side Link Feedback Channel (PSFCH) with adjacent gap symbols is illustrated. Symbols before and / or after the feedback can be used for turnaround between receiving data and transmitting feedback. This gap allows a device to switch from operating as a transmitting device to preparing to operate as a receiving device (e.g., in a subsequent time slot). As illustrated, data can be transmitted in the remaining REs. This data may include the data message described herein. The positions of any of the data, DMRS, SCI, feedback, gap symbol, and / or LBT symbol can be related to... Figure 2 The examples described differ. In some cases, multiple time slots can be aggregated together.

[0058] Figure 3 This is a block diagram 300 illustrating communication between a first wireless communication device 310 and a second wireless communication device 350 via a sidelink. In some examples, devices 310 and 350 may communicate via V2X or other D2D communication. This communication may be based on a sidelink using a PC5 interface. Devices 310 and 350 may include UEs, RSUs, base stations, etc. Packets may be provided to a controller / processor 375 implementing Layer 3 and Layer 2 functions. Layer 3 includes the Radio Resource Control (RRC) layer, and Layer 2 includes the Packet Data Convergence Protocol (PDCP) layer, Radio Link Control (RLC) layer, and Media Access Control (MAC) layer.

[0059] Transmit (TX) processor 316 and receive (RX) processor 370 implement Layer 1 functions associated with various signal processing functions. Layer 1, including the physical (PHY) layer, may include error detection on the transport channel, forward error correction (FEC) encoding / decoding of the transport channel, interleaving, rate matching, mapping to the physical channel, modulation / demodulation of the physical channel, and MIMO antenna processing. TX processor 316 processes the mapping to the signal constellation based on various modulation schemes (e.g., binary phase shift keying (BPSK), quadrature phase shift keying (QPSK), M-phase shift keying (M-PSK), M-quadrature amplitude modulation (M-QAM)). The encoded and modulated symbols can then be segmented into parallel streams. Each stream can then be mapped to OFDM subcarriers, multiplexed with a reference signal (e.g., pilot) in the time and / or frequency domains, and then combined using an inverse fast Fourier transform (IFFT) to produce a physical channel carrying a stream of time-domain OFDM symbols. The OFDM streams are spatially pre-coded to produce multiple spatial streams. The channel estimate from channel estimator 374 can be used to determine the coding and modulation scheme, as well as spatial processing. The channel estimate can be derived from a reference signal and / or channel condition feedback transmitted by device 350. Each spatial stream can then be provided to a different antenna 320 via a separate transmitter 318 (TX). Each transmitter 318 (TX) can modulate an RF carrier for transmission using its respective spatial stream.

[0060] At device 350, each receiver 354 (RX) receives signals through its respective antenna 352. Each receiver 354 (RX) recovers the information modulated onto the RF carrier and provides the information to the receive (RX) processor 356. The TX processor 368 and RX processor 356 implement Layer 1 functions associated with various signal processing functions. The RX processor 356 can perform spatial processing on the information to recover any spatial stream destined for device 350. If multiple spatial streams are destined for device 350, they can be combined by the RX processor 356 into a single OFDM symbol stream. The RX processor 356 then uses a Fast Fourier Transform (FFT) to transform the OFDM symbol stream from the time domain to the frequency domain. The frequency domain signal comprises a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols and reference signals on each subcarrier are recovered and demodulated by determining the most probable signal constellation point transmitted by device 310. These soft decisions can be based on a channel estimate calculated by the channel estimator 358. The soft decision is then decoded and deinterleaved to recover the data and control signals originally transmitted by device 310 on the physical channel. The data and control signals are then provided to controller / processor 359, which implements Layer 3 and Layer 2 functions.

[0061] The controller / processor 359 may be associated with a memory 360 that stores program code and data. The memory 360 may be referred to as a computer-readable storage medium. The controller / processor 359 can provide demultiplexing, packet reassembly, decryption, header decompression, and control signal processing between transport and logical channels. The controller / processor 359 is also responsible for error detection using ACK and / or NACK protocols to support HARQ operation.

[0062] Similar to the functions described in the transmission of the combined device 310, the controller / processor 359 can provide RRC layer functions associated with system information (e.g., MIB, SIB) acquisition, RRC connection, and measurement reporting; PDCP layer functions associated with header compression / decompression and security (encryption, decryption, integrity protection, integrity verification); RLC layer functions associated with upper-layer PDU transmission, error correction via ARQ, RLC SDU connection, segmentation and reassembly, RLC data PDU resegmentation, and RLC data PDU reordering; and MAC layer functions associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto TBs, demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction via HARQ, priority processing, and logical channel priority.

[0063] The channel estimate derived by the channel estimator 358 from the reference signal or feedback sent from the device 310 can be used by the TX processor 368 to select an appropriate coding and modulation scheme and facilitate spatial processing. The spatial stream generated by the TX processor 368 can be provided to different antennas 352 via individual transmitters 354 (TX). Each transmitter 354 (TX) can use its respective spatial stream to modulate an RF carrier for transmission.

[0064] The transmission is processed at device 310 in a manner similar to the receiver function described at device 350. Each receiver 318 (RX) receives the signal through its respective antenna 320. Each receiver 318 (RX) recovers the information modulated onto the RF carrier and provides the information to the RX processor 370.

[0065] The controller / processor 375 may be associated with a memory 376 that stores program code and data. The memory 376 may be referred to as a computer-readable storage medium. The controller / processor 375 provides demultiplexing, packet reassembly, decryption, header decompression, and control signal processing between the transport channel and the logical channel. The controller / processor 375 is also responsible for error detection using ACK and / or NACK protocols to support HARQ operation.

[0066] At least one of the following: TX processor 368, RX processor 356, controller / processor 359, TX processor 316, RX processor 370, or controller / processor 375 can be configured to perform a combination. Figure 1 The sidelink discovery component 198 can be configured to, for example, indicate whether the PSSCH carries discovery-related messages and / or monitor discovery-related messages over a specified resource pool and / or duration. The sidelink discovery component 198 can also be configured to perform resource allocation for discovery-related messages.

[0067] Figure 4 Example 400 illustrates wireless communication between devices based on side-link communication. This communication can be based on a time-slot structure, including combinations of... Figure 2 In terms of description, for example, transmitting UE 402 may transmit transmission 414, which includes, for example, a control channel and / or a corresponding data channel, and transmission 414 may be received by receiving UEs 404 and 406. The control channel may include information for decoding the data channel and may also be used by the receiving device to avoid interference by avoiding transmission on occupied resources during data transmission. The number of RBs occupied by the data transmission and the number of TTIs may be indicated in a control message from the transmitting device. UEs 402, 404, 406, and 408 may also have the capability to operate as transmitting devices in addition to operating as receiving devices. Therefore, UEs 406 and 408 are described as transmitting transmissions 416 and 420. Transmissions 414, 416, and 420 may be broadcast or multicast to nearby devices. For example, UE 402 may transmit communications (e.g., data) for other UEs within range 401 of UE 402 to receive. In addition, or alternatively, RSU 407 may receive communications from UE 402, 406, 408 and / or send communications 418 to UE 402, 406, 408.

[0068] Sidelink communication exchanged directly between devices may include discovery messages for sidelink UEs to find nearby UEs, and / or may include sensing resource reservations of other UEs to select resources for transmission. Sidelink communication may be based on different types or modes of resource allocation mechanisms. In a first resource allocation mode (which may be referred to herein as "Mode 1"), centralized resource allocation may be provided. For example, base station 102 or 180 may determine resources for sidelink communication and allocate these resources to different UEs 104 for sidelink transmission. In this first mode, the sidelink UE receives the allocation of sidelink resources from base station 102 or 180. In a second resource allocation mode (which may be referred to herein as "Mode 2"), distributed resource allocation may be provided. In Mode 2, each UE may autonomously determine resources for sidelink transmission. To coordinate the selection of sidelink resources by each UE, each UE may use sensing technology to monitor resource reservations of other sidelink UEs and may select resources for sidelink transmission from unreserved resources. These resource allocation mechanisms for sidelinks can provide power savings, for example, at the physical layer or media access control (MAC) layer. Power savings can be beneficial for sidelink applications such as public safety applications, commercial applications, and wearable devices, which may include both periodic and non-periodic traffic.

[0069] Figure 5This includes a schematic diagram 500 illustrating an example of wireless relay between a remote UE 502, a relay UE 506, and a base station 504 via a sidelink. Base station 504 can provide communication coverage for a geographic coverage area 510. As shown, remote UE 502 and relay UE 506 can be within the coverage area 510 provided by base station 504. Remote UE 502 can be connected (e.g., via RRC connection) to base station 504 and can request relay services for various purposes. For example, atmospheric and environmental interference may exist between remote UE 502 and base station 504, where remote UE 502 may need to send or receive data via relay UE 506. In other examples, remote UE 502 may wish to utilize link diversity to improve transmission speed and / or reliability, where remote UE 502 is configured to connect to base station 504 via multiple links (or connections). For example, remote UE 502 can employ dual connectivity by simultaneously connecting directly (e.g., via RRC connection) and indirectly (e.g., via relay UE 506 connected via a sidelink) to base station 504. In another example, remote UE 502 may be outside coverage area 510 and unable to establish a direct connection with base station 504. Therefore, remote UE 502 can communicate with base station 504 via relay UE 506. Remote UE 502 can communicate with base station 504 via the Uu interface and with relay UE 506 via the PC5 interface. Thus, remote UE 502 can communicate with base station 504 using two simultaneous protocol stacks through two different paths. Figure 5 Schematic diagram 520 provides an example PC5 protocol stack that can be used by remote UE 502 and relay UE 506 to establish a PC5 connection.

[0070] Figure 6 This section illustrates an example of resource allocation based on Sensing 600. A UE can perform sensing by monitoring Sidelink Control Information (SCI), which instructs other UEs to use or reserve resources for transmitting sidelink transmissions. The SCI indicating resources can be described as reserving sidelink resources. The indicated resources can be referred to as sidelink reservations. The UE can monitor a set of frequency resources within a time window, such as... Figure 6As shown in section 602, this frequency range can be based on a set of resources used for sidelink communication. The time and frequency resources used for sidelink communication can be referred to as a resource pool. The UE can determine the available resources in the resource pool based on unreserved remaining resources. For example, in mode 2 resource allocation, a UE interested in transmitting packets can perform sensing (i.e., monitor activity in the communication resource pool), and the UE can determine whether a resource in a future time slot has been reserved by another UE in a past time slot. If the resource has not been reserved by another UE for transmitting higher-priority packets, or if the resource has been reserved by another UE but the RSRP of the signal transmitted by that other UE is below a threshold, then the UE can use the resource. In another example, the UE can reserve resources if the measurement result for the corresponding SCI received in the sensing window meets a threshold, such as an RSRP threshold or other signal strength threshold. In other words, a resource pool can be a set of time / frequency resources on which sidelink communication can occur. The resource pool can be pre-configured (i.e., pre-loaded) on the UE, or it can be configured by the base station.

[0071] After a resource selection is triggered, at 604, the UE can select a resource from the available resources in the resource pool for transmission. Resource selection can be triggered, for example, by a UE having data for transmission. Figure 6 This describes example resource pool 606, and the resources that the UE selects from available resources that were not reserved by the SCI received during the sensing window.

[0072] As discussed, sidelink devices can exchange direct sidelink communication with each other. To establish sidelink communication between sidelink devices (e.g., UEs), one sidelink device may attempt to discover another sidelink device via a discovery process at a higher layer of the protocol stack (e.g., the application). The discovery mechanism can also be configured at a lower layer of the protocol stack. In one type of sidelink discovery model, such as... Figure 7A As shown in schematic diagram 700A, to determine the presence of another UE, first UE 702 can broadcast / multicast a discovery message. This discovery message can be an announcement message 706. First UE 702 can broadcast the announcement message 706 indicating its presence as a sidelink device to other UEs within its transmission range (e.g., UE 704). In response, if UE 704 wants to establish sidelink communication with first UE 702, UE 704 can send a connection request message 708 (which can also be referred to as a "connection establishment request message") to first UE 702. For example, see reference. Figure 4UE 402 can broadcast an announcement message, which can be received by UEs 404 and 406, as well as other sidelink devices such as RSU 407 within UE 402's transmission range 401. A sidelink UE (such as UE 404) receiving the announcement message can respond to a first UE (such as UE 402) using a message (such as a connection request). After discovering each other, UEs 402 and 404 can exchange sidelink communications. The first sidelink device or first UE (such as UE 402 or 702) that sends the announcement message (such as announcement message 706) can be referred to as the announcing UE. The radio device (such as UEs 404, 406, 704) that sends a discovery response or monitoring announcement message can be referred to as the monitoring UE. The discovery type involving the broadcast announcement and response can be referred to as the first discovery model, or "Model A" sidelink discovery.

[0073] In another type of sidelink discovery model, such as Figure 7B As shown in diagram 700B, a first UE 712 (e.g., UE 402) can broadcast a solicitation message 716 (which may also be referred to as a "discovery request message") to one or more UEs 714. The first UE 712 that sends the solicitation message 716 can be referred to as a discoverer UE. In response, a UE 714 that receives the solicitation message 716 can process the request and send a response message 718 to the first UE 712. The UE 714 that sends the response message 718 can be referred to as a discoveree UE. The discovery type that includes a solicitation message or a discovery request message can be referred to as a second type of discovery or "Model B" sidelink discovery. As an example, in Model A sidelink discovery, an announcement message informs other sidelink UEs "I am here," while in Model B sidelink discovery, a solicitation message or discovery request asks nearby sidelink devices "Who is there?" or "Are you there?".

[0074] For sidelink devices to establish direct communication with each other based on the aforementioned sidelink discovery model, since broadcast / discovery messages (e.g., announcement message 706, solicitation message 716, etc.) can be transmitted in the same sidelink resource pool as discovery response messages (e.g., connection request message 708, response message 718, etc.), the receiving sidelink device (e.g., the monitoring UE or the discovered UE) or the transmitting sidelink device (e.g., the announcement UE or the discovered UE) can be configured to continuously monitor the sidelink resource pool for discovery messages or discovery response messages. Continuous monitoring for discovery-related messages may increase power consumption at the receiving sidelink device and / or the transmitting sidelink device, which may also degrade their performance.

[0075] Sidelink resource reservation can be periodic or aperiodic. For example, a UE can periodically reserve resources, such as by indicating a reservation period in the SCI. Therefore, when periodic resource reservation is enabled, the reservation in the SCI may be repeated in signaled periods. In some examples, a UE can indicate resource reservation in multiple SCI portions. For example, a UE can transmit a first portion of the reservation in the Physical Side Link Control Channel (PSCCH) area and a second portion of the reservation in the Physical Side Link Shared Channel (PSSCH) area. For example, a first-phase control (e.g., SCI-1) can be transmitted on the PSCCH and contain information related to resource allocation and decoding of the second-phase control (e.g., SCI-2), while the second-phase control can be transmitted on the PSSCH and contain information (SCH) for decoding data. Therefore, multiple resources can be indicated or reserved by a combination of a first SCI portion indicated in the PSCCH area and a second SCI portion in the PSSCH area. For example, the first SCI portion in the PSCCH can reserve resources for the UE in the PSSCH, and the first SCI portion can also indicate to the receiving UE that there is a second SCI portion or more in the PSSCH (e.g., two-stage SCI). The second SCI portion can reserve other resources or provide signaling and / or information to the UE, which may be independent of the resources reserved in the first SCI portion.

[0076] Figure 8This is a schematic diagram 800 illustrating an example of a two-phase PSCCH. To reduce control overhead and improve processing timelines, the SCI used for sidelink granting can be divided into two or more parts. A first SCI part 802 can be transmitted within a control area (e.g., PSCCH area 808), while a second SCI part 804 can be transmitted within a downlink service area (e.g., PSSCH area 810). PSCCH area 808 and PSSCH area 810 can together form a single time slot. The first SCI part 802 can include initial control information regarding sidelink transmission, such as resource allocation (RA) or other resource reservation information in SCH 806, the rank and modulation order of the sidelink allocation, etc. Furthermore, the first SCI part 802 can also include control information regarding the second SCI part 804. In some examples, the control information can indicate the number (size) of resource elements and the code rate of the second SCI part 804. The control information can further indicate the position (e.g., the start resource element) and code rate of the second SCI part 804. The second SCI section 804 may include residual control information regarding sidelink assignment. For example, the residual control information may include non-time-critical control information or other resource allocations for data transmission in SCH 806, such as source and destination IDs for data transmission. In one aspect, the format of the first SCI section 802 (e.g., SCI-1) may include one or more of the following: priority (QoS value), PSSCH resource assignment (e.g., frequency / time resources for PSSCH), resource reservation period (e.g., if enabled), PSSCH DMRS mode (e.g., if more than one mode is configured), second SCI format (e.g., information about the size of the second SCI), a 2-bit beta offset for second-stage control resource allocation, the number of PSSCH DMRS ports (e.g., 1 or 2), a 5-bit MCS, and / or one or more reservation bits, etc.

[0077] When a transmitting device (e.g., a sidelink device, a first UE, a base station, or an RSU) sends a PSSCH to a receiving device (e.g., a second UE or another sidelink device) via the sidelink, the receiving device can respond to the transmitting device with a HARQ feedback (e.g., ACK / NACK) corresponding to the received PSSCH via the Physical Sidelink Feedback Channel (PSFCH). The PSFCH can share the same sidelink resource pool as the PSCCH and PSSCH, where the receiving device can determine the PSFCH resources for sending HARQ feedback from the configured PSFCH resource pool. The PSFCH can be enabled for unicast and / or multicast communication. For unicast communication, the receiving device can use the PSFCH to send a 1-bit ACK / NACK feedback (e.g., 0 = NACK, 1 = ACK, etc.) to the transmitting device to indicate whether the transmitting device has successfully decoded the received PSSCH. For multicast communication, the receiving device can send HARQ feedback via the PSFCH in one of two feedback modes. In the first feedback mode, when the receiving device fails to decode the received PSSCH, it can send negative feedback (e.g., NACK) to the transmitting device; conversely, when the receiving device successfully decodes the received PSSCH, it can skip sending positive feedback (e.g., ACK) to the transmitting device. This first mode can be referred to as NACK-based feedback or NACK-only feedback. In the second mode, when the receiving device successfully decodes the received PSSCH, it can send positive feedback to the transmitting device; conversely, when the receiving device fails to decode the received PSSCH, it can send negative feedback to the transmitting device.

[0078] Figure 9This is a schematic diagram 900 illustrating an example PSFCH configuration. PSFCH resources (e.g., a PSFCH resource pool) can be periodic, system-wide feedback resources configured (e.g., loaded onto a sidelink device) or configured by the network (e.g., by a base station). PSFCH resources can also be configured with a period N, which can indicate the frequency at which PSFCH resources are configured in the sidelink resource pool. For example, period N can be 1, 2, or 4 time slots. If N = 1 time slot, it can indicate that the PSFCH resource is configured (e.g., available) in every time slot within the sidelink resource pool; if N = 2, as shown in schematic diagram 900, it can indicate that the PSFCH resource is configured in every two time slots within the sidelink resource pool, and so on. In one example, as shown in schematic diagram 900, when PSFCH resources are configured for a time slot, the PSFCH resource can occupy three OFDM symbols within that time slot, one symbol for slot 902 and two symbols for PSFCH 904. For example, gap 902 can use symbols before and / or after PSFCH 904, and gap 902 can be used by a sidelink device for turnaround between data reception and HARQ feedback transmission. The number of physical resource blocks (PRBs) for PSFCH can be configured, for example, via a bitmap. For example, in one of the PUCCH formats (e.g., format 0), there may be a resource block (RB) carrying HARQ-ACK information for a single PSSCH transmission, where the PSFCH format 0 sequence can be repeated over two PSFCH symbols. There can also be a timing gap K configured for PSFCH resources, where the timing gap can indicate the duration between the time slot carrying PSSCH and the corresponding time slot of the PSFCH resource configured to provide HARQ feedback for PSSCH. Therefore, when a receiving device receives PSSCH in time slot n, the receiving device can transmit the corresponding HARQ feedback via the PSFCH resource in time slot (n+K). For example, as shown in diagram 900, if the timing gap K = 2, then the side link device that receives PSSCH in time slot n can use PSSCH resources to send the corresponding HARQ feedback within time slot n+2.

[0079] Figure 10This is a schematic diagram 1000 illustrating the structure of an exemplary sidelink resource pool 1002 and a sidelink time slot 1004 within the sidelink resource pool 1002. The sidelink resource pool 1002 can be a collection of time and / or frequency resources on which sidelink communication can occur. The sidelink resource pool 1002 can be loaded onto the UE or configured by the base station. Discovery messages (e.g., announcement messages 706 and solicitation messages 716) can be transmitted in the same resource pool as communication messages (e.g., connection request messages 708 and response messages 718). Furthermore, discovery messages and communication messages can be transmitted using the same PSSCH structure. In other words, for resource efficiency, the sidelink resource pool 1002 can be shared between discovery messages and communication messages. Since the sidelink UE uses the same PSSCH structure for discovery messages and communication messages, the sidelink UE can check whether the received / monitored PSSCH carries discovery messages and / or communication messages from a higher layer (e.g., PC5-discovery layer in schematic diagram 520). If the sidelink UE has the ability to identify message types (e.g., discovery messages or communication messages) at the physical layer (e.g., the PC5-PHY layer in schematic diagram 520), the sidelink UE can achieve additional power savings.

[0080] The aspects proposed herein can improve resource allocation for sidelink communication and can improve the sidelink discovery process at the physical layer to achieve resource efficiency and / or UE power savings. Power consumption at the receiving sidelink device and / or transmitting sidelink device can be reduced when the device is performing a sidelink discovery process. In one aspect of this disclosure, a transmitting sidelink device (e.g., UE 104, 402, 502, 702, 712) can send an indication to one or more receiving sidelink devices (e.g., UE 104, 404, 406, 408, 506, 704, 714) to indicate whether the PSSCH (e.g., subsequent PSSCHs) carries a discovery message (e.g., announcement message 706 and solicitation message 716) and / or a communication message (e.g., connection request message 708 and response message 718). The transmitting sidelink device can then send the discovery message and / or communication message in the PSSCH based at least in part on the indication. The receiving traversal device can monitor this indication from the transmitting traversal device to determine whether the PSSCH carries a discovery message or a communication message. If the receiving traversal device monitors / receives an indication that the PSSCH carries a discovery message, it can monitor the discovery message in the PSSCH. On the other hand, if the receiving traversal device monitors / receives an indication that the PSSCH does not carry a discovery message, it can exclude or skip monitoring the discovery message in the PSSCH to reduce power consumption.

[0081] In one example, such asFigure 11 As shown in schematic diagram 1100, transmitting device 1102 (e.g., a first UE, a sidelink device) may send the indication to receiving device 1104 (e.g., a second UE, another sidelink device) in a first SCI portion 1116 (e.g., SCI-1). For example, as shown in example communication flow 1150, at 1106, transmitting device 1102 may send the indication to receiving device 1104 in the first SCI portion 1116 to indicate whether PSSCH 1120 (e.g., PSSCH after the first SCI portion 1116) carries discovery messages (e.g., announcement messages 706 and solicitation messages 716) and / or communication messages (e.g., connection request messages 708 and response messages 718). This indication may be included in physical layer signaling, for example, in an SCI transmitted via PSCCH, in PSFCH, or in resources supporting PSFCH, or in a channel configured to carry information about whether the sidelink transmission will include discovery messages. For the purposes of this disclosure, the term "physical layer" may refer to the lowest layer or layer 1 of a communication system. The physical layer can provide mechanical, electrical, and other functional aids for transmitting signals, such as electromagnetic waves (e.g., for wireless networks), electrical signals, and / or optical signals (fiber optics, lasers). Devices and network components associated with the physical layer may include antennas, amplifiers, and / or transceivers. Therefore, physical layer signaling may refer to the transmission of signals over a network via physical devices. The functions of the physical layer may include encoding and signaling, where data is converted from bits residing within electronic devices into signals that can be transmitted over the network as radio waves or voltages. For example, transmitting device 1102 may transmit this indication in a physical-side crosslink discovery indication channel, which indicates whether the PSSCH or PSCCH carries a discovery message. The physical-side crosslink discovery indication channel may be in the same time slot as the PSSCH and / or PSCCH.

[0082] The indication may include one or more of a source ID (e.g., of the sending device 1102) or a destination ID (e.g., of the receiving device 1104), such that the receiving device 1104 can identify the sending device 1102 at least in part based on the source ID and / or determine whether it is the recipient of the indication or communication / discovery message at least in part based on the destination ID.

[0083] Return to reference Figure 11The first SCI portion 1116 can be transmitted in PSCCH 1118 corresponding to PSSCH 1120. In one example, the transmitting device can use one or more reserved bits of the first SCI portion 1116 to indicate the presence of a discovery message and / or communication message. Then, at 1108, the transmitting device 1102 can send the discovery message and / or communication message to the receiving device 1104 based on this indication. For example, if the indication indicates that the transmitting device 1102 is transmitting a discovery message in PSSCH 1120, then the transmitting device 1102 transmits the discovery message in PSSCH 1120. The transmitting device 1102 can optionally indicate a duration 1122 within PSSCH 1120 during which the discovery message and / or communication message will be transmitted, such that the receiving device 1104 can monitor the discovery message and / or communication message during the duration 1122, and can exclude or skip monitoring the discovery message and / or communication message outside the duration 1122 to achieve additional power savings.

[0084] For receiving device 1104, as shown in 1110, receiving device 1104 can monitor or receive indications from transmitting device 1102. In 1112, receiving device 1104 can determine whether PSSCH 1120 carries discovery messages and / or communication messages based on the received / monitored indications. In 1114, receiving device 1104 can monitor discovery messages and / or communications based on this determination. For example, if the indication indicates that transmitting device 1102 is sending a discovery message in PSSCH 1120, receiving device 1104 can monitor discovery messages in PSSCH 1120. However, if the indication indicates that PSSCH 1120 does not carry discovery messages, receiving device 1104 can exclude or skip monitoring discovery messages in PSSCH 1120 to reduce power consumption.

[0085] In another example, such as Figure 12As shown in schematic diagram 1200, transmitting device 1202 (e.g., a first UE, a side-link device) can send the indication to receiving device 1204 (e.g., a second UE, another side-link device) in a second SCI portion 1217 (e.g., SCI-2). For example, as shown in example communication flow 1250, at 1206, transmitting device 1202 can send the indication to receiving device 1204 in the second SCI portion 1217 to indicate whether PSSCH 1220 carries a discovery message and / or a communication message. This indication can be included in / sent in physical layer signaling, such as in an SCI sent via PSCCH. For example, transmitting device 1202 can send the indication in a physical side-link discovery indication channel, which indicates whether PSSCH or PSCCH carries a discovery message. The physical side-link discovery indication channel can be in the same time slot as PSSCH and / or PSCCH. The second SCI portion 1217 can be transmitted along with the discovery message and / or communication message in PSSCH 1220. Then, at 1208, the transmitting device 1202 can transmit the discovery message and / or communication message to the receiving device 1204 based on the indication. For example, if the indication indicates that the transmitting device 1202 is transmitting a discovery message in PSSCH 1220, then the transmitting device 1202 transmits the discovery message in PSSCH 1220. The transmitting device 1202 can optionally indicate a duration 1222 within PSSCH 1220 during which the discovery message and / or communication message will be transmitted, such that the receiving device 1204 can monitor the discovery message and / or communication message during the duration 1222, and can exclude or skip monitoring the discovery message and / or communication message outside the duration 1222 to achieve additional power savings.

[0086] The indication may include one or more of a source ID (e.g., for sending device 1202) or a destination ID (e.g., for receiving device 1204), such that receiving device 1204 can identify sending device 1202 at least in part based on the source ID and / or determine whether it is the recipient of the indication or communication / discovery message at least in part based on the destination ID.

[0087] For receiving device 1204, as shown in 1210, receiving device 1204 can monitor or receive the indication from transmitting device 1202. In 1212, receiving device 1204 can determine whether PSSCH 1220 carries a discovery message and / or communication message based on the received / monitored indication. In 1214, receiving device 1204 can monitor the discovery message and / or communication based on this determination. For example, if the indication indicates that transmitting device 1202 is sending a discovery message in PSSCH 1220, receiving device 1204 can monitor the discovery message in PSSCH 1220. However, if the indication indicates that PSSCH 1220 does not carry a discovery message, receiving device 1204 can exclude or skip monitoring the discovery message in PSSCH 1220 to reduce power consumption.

[0088] For transmitting device 1202, there are several ways to indicate at 1206 whether a discovery message and / or communication message exists in PSSCH 1220. In one example, transmitting device 1202 can use one or more reserved or existing bits of the second SCI section 1217 to indicate to receiving device 1204 whether a discovery message and / or communication message exists in PSSCH 1220. For example, the indication can be made using an existing SCI-2 format by changing the use of one or more bits in the existing SCI-2 format. Alternatively or additionally, a new SCI-2 format can be configured for transmitting device 1202 and receiving device 1204 for transmitting the indication.

[0089] In another example, transmitting device 1202 may indicate to receiving device 1204, at least in part, the presence of discovery messages and / or communication messages in PSSCH 1220 based on demodulation reference signals (DMRS) and / or resource mapping.

[0090] In one aspect, transmitting device 1202 may indicate whether PSSCH 1220 carries discovery messages and / or communication messages based on PSCCH DMRS mapping and / or PSCCH resource mapping (e.g., PSCCH 1218). For example, a first mapping from the lowest physical resource block (PRB) to the highest PRB may indicate that PSSCH 1220 includes discovery messages, and a second mapping from the highest PRB to the lowest PRB may indicate that PSSCH 1220 does not include discovery messages or carries communication messages. Alternatively, a first mapping from the lowest PRB to the highest PRB may be used to indicate that PSSCH 1220 does not include discovery messages or carries communication messages, and conversely, a second mapping from the highest PRB to the lowest PRB may be used to indicate that PSSCH 1220 includes discovery messages. Mapping rules may be pre-configured (e.g., pre-loaded) on transmitting device 1202 and / or receiving device 1204, or they may be configured by the base station.

[0091] In another example, transmitting device 1202 can indicate that PSSCH 1220 does not carry a discovery message or carries a communication message by mapping one or more PSCCH DMRS from the first DMRS symbol to the last DMRS symbol of one or more PSCCH DMRS, and transmitting device 1202 can indicate that PSSCH 1220 carries a discovery message by mapping one or more PSCCH DMRS from the last DMRS symbol to the first DMRS symbol of one or more PSCCH DMRS. Alternatively, transmitting device 1202 can indicate that PSSCH 1220 carries a discovery message by mapping one or more PSCCH DMRS from the first DMRS symbol to the last DMRS symbol of one or more PSCCH DMRS, and conversely, transmitting device 1202 can indicate that PSSCH 1220 does not carry a discovery message or carries a communication message by mapping one or more PSCCH DMRS from the last DMRS symbol to the first DMRS symbol of one or more PSCCH DMRS.

[0092] In other words, based on the DMRS resource mapping, transmitting device 1202 can indicate the presence of a communication message in PSSCH 1220 by mapping the DMRS from the lowest PRB to the highest PRB, and transmitting device 1202 can indicate the presence of a discovery message in PSSCH 1220 by mapping the DMRS from the highest PRB to the lowest PRB. Furthermore, or alternatively, if the DMRS is transmitted over multiple symbols, transmitting device 1202 can indicate the presence of a communication message in PSSCH 1220 by mapping the DMRS from the first DMRS symbol to the last DMRS symbol, and transmitting device 1202 can indicate the presence of a discovery message in PSSCH 1220 by mapping the DMRS from the last DMRS symbol to the first DMRS symbol.

[0093] In another aspect, transmitting device 1202 can indicate whether PSSCH 1220 carries discovery messages and / or communication messages based on PSSCH DMRS mapping and / or PSSCH resource mapping. For example, a first mapping of PSSCH 1220 from the lowest PRB to the highest PRB can indicate that PSSCH 1220 carries discovery messages, while a second mapping of PSSCH 1220 from the highest PRB to the lowest PRB can indicate that PSSCH 1220 does not carry discovery messages or carries communication messages. Alternatively, a first mapping of PSSCH 1220 from the lowest PRB to the highest PRB can indicate that PSSCH 1220 does not carry discovery messages or carries communication messages, and conversely, a second mapping of PSSCH 1220 from the highest PRB to the lowest PRB can indicate that PSSCH 1220 carries discovery messages.

[0094] In another example, if the second SCI portion 1217 is transmitted via multiple PSSCH symbols, the transmitting device 1202 can indicate that PSSCH 1220 does not carry a discovery message or carries a communication message by mapping one or more PSSCH DMRS from the first PSSCH symbol carrying the second SCI portion 1217 to the last PSSCH symbol carrying the second SCI portion 1217, and the transmitting device 1202 can indicate that PSSCH 1220 carries a discovery message by mapping one or more PSSCH DMRS from the last PSSCH symbol carrying the second SCI portion 1217 to the first PSSCH symbol carrying the second SCI portion 1217. Alternatively, if the second SCI portion 1217 is transmitted via multiple PSSCH symbols, the transmitting device 1202 can indicate that PSSCH 1220 carries a discovery message by mapping one or more PSSCH DMRS from the first PSSCH symbol carrying the second SCI portion to the last PSSCH symbol carrying the second SCI portion, and the transmitting device 1202 can indicate that PSSCH 1220 does not carry a discovery message or carries a communication message by mapping one or more PSSCH DMRS from the last PSSCH symbol carrying the second SCI portion 1217 to the first PSSCH symbol carrying the second SCI portion 1217.

[0095] In other words, based on the resource mapping of PSSCH 1220 (e.g., carrying the second SCI portion 1217), transmitting device 1202 can indicate the presence of a communication message by mapping PSSCH 1220 from the lowest PRB to the highest PRB, and transmitting device 1202 can indicate the presence of a discovery message by mapping PSSCH 1220 from the highest PRB to the lowest PRB. Furthermore or alternatively, if the second SCI portion 1217 is transmitted via multiple symbols, transmitting device 1202 can indicate the presence of a communication message by mapping DMRS from the first PSSCH (carrying the second SCI portion 1217) symbol to the last PSSCH symbol, and transmitting device 1202 can indicate the presence of a discovery message by mapping DMRS from the last PSSCH (carrying the second SCI portion 1217) symbol to the first PSSCH symbol.

[0096] In another aspect of this disclosure, such as Figure 13 As shown in schematic diagram 1300, transmitting device 1302 (e.g., a first UE, a first radio device) can indicate to receiving device 1304 (e.g., a second UE, a second radio device) via a discovery indication signal (DIS) whether PSSCH 1320 or PSCCH 1318 carries a discovery message and / or a communication message, wherein the discovery indication signal can be a physical channel / signal (e.g., a physical-side walkway discovery indication channel). For example, as shown in example communication flow 1350, at 1306, transmitting device 1302 can send discovery indication signal 1324 to receiving device 1304 to indicate whether PSSCH 1320 (e.g., a PSSCH carrying discovery indication signal 1324) or PSCCH 1318 carries a discovery message and / or a communication message. Therefore, discovery indication signal 1324 can be included in / sent in physical layer signaling. For example, transmitting device 1302 can transmit a discovery indication signal 1324 in the physical-side cross-link discovery indication channel, which indicates whether the PSSCH or PSCCH carries a discovery message. The physical-side cross-link discovery indication channel can be in the same time slot as the PSSCH and / or PSCCH.

[0097] The discovery indication signal 1324 may include one or more of a source ID (e.g., of the sending device 1302) or a destination ID (e.g., of the receiving device 1304), such that the receiving device 1304 can identify the sending device 1302 at least in part based on the source ID and / or determine whether it is the recipient of the discovery indication signal 1324 or the communication / discovery message at least in part based on the destination ID.

[0098] In one example, the discovery indication signal 1324 may be a sequence or include sequences (e.g., sequence-based), a PSCCH with a defined SCI format, and / or a PSFCH, wherein the discovery indication signal 1324 may include information indicating whether a discovery message will be sent in PSSCH 1320 or not. Transmitting device 1302 may transmit the discovery indication signal 1324 in the same time slot as PSSCH 1320 and / or PSCCH 1318, and may also transmit the discovery indication signal 1324 in PSCCH 1318 and / or PSSCH 1320. Therefore, the discovery indication signal 1324 may share one or more DMRSs with PSSCH 1320, or the discovery indication signal 1324 may include one or more DMRSs (e.g., having its own DMRS not shared with PSSCH 1320). Furthermore, the discovery indication signal 1324 may share the same sidelink resource pool as discovery messages and communication messages. However, the discovery indication signal 1324 may not use resources that conflict with one or more DMRS of PSSCH 1320 or PSCCH 1318. Transmitting device 1302 may also transmit the discovery indication signal 1324 on a different physical channel than PSCCH 1318 and / or PSSCH 1320. In one example, the discovery indication signal 1324 may be associated with PSCCH 1318 and / or PSSCH 1320 carrying a discovery message. Therefore, the presence of the discovery indication signal 1324 indicates that a discovery message will be transmitted in PSCCH 1318 and / or PSSCH 1320. In other words, the discovery indication signal 1324 may be associated with a PSCCH / PSSCH carrying a discovery message or with a PSCCH / PSSCH carrying a communication message, or the discovery indication signal 1324 may always be transmitted. Therefore, when receiving device 1304 receives / detects discovery indication signal 1324 in PSSCH or PSCCH, receiving device 1304 can identify whether PSSCH or PSCCH carries discovery message and / or communication message.

[0099] Optionally or additionally, the discovery indication signal 1324 may include additional functionality. In one example, the discovery indication signal 1324 may include one or more reference signals for performing time tracking, frequency tracking, and / or Doppler estimation to decode PSCCH 1318 and / or PSSCH 1320. In another example, the discovery indication signal 1324 may include one or more reference signals that can be used by the transmitting device 1302 and / or the receiving device 1304 to perform mobility management such as radio link monitoring.

[0100] Then, at 1308, transmitting device 1302 may send a discovery message and / or communication message to receiving device 1304 based on discovery indication signal 1324. For example, if discovery indication signal 1324 indicates that transmitting device 1302 is sending a discovery message in PSSCH 1320, then transmitting device 1302 sends a discovery message in PSSCH 1320. Transmitting device 1302 may optionally indicate a duration (e.g., 1122, 1222) within PSSCH 1320 during which the discovery message and / or communication message will be sent, such that receiving device 1304 can monitor the discovery message and / or communication message during this duration and can exclude or skip monitoring the discovery message and / or communication message outside this duration to achieve additional power savings.

[0101] For receiving device 1304, as shown in 1310, receiving device 1304 can monitor or receive a discovery indication signal 1324 from transmitting device 1302. In 1312, receiving device 1304 can determine, based on the received / monitored discovery indication signal 1324, whether PSSCH 1320 carries a discovery message and / or communication message. In 1314, receiving device 1304 can monitor the discovery message and / or communication based on this determination. For example, if the discovery indication signal 1324 indicates that transmitting device 1302 is sending a discovery message in PSSCH 1320, then receiving device 1304 can monitor the discovery message in PSSCH 1320. However, if the indication indicates that PSSCH 1320 does not carry a discovery message, receiving device 1304 can exclude or skip monitoring the discovery message in PSSCH 1320 to reduce power consumption.

[0102] In another aspect of this disclosure, such as Figure 14As shown in schematic diagram 1400, transmitting device 1402 (e.g., a first UE, a first radio device) can indicate to receiving device 1404 (e.g., a second UE, a second radio device) whether the PSSCH carries a discovery message and / or communication message by sending a discovery indication to receiving device 1404 using one or more PSSCH resources. For example, as shown in example communication flow 1450, at 1406, transmitting device 1402 can send discovery indication 1424 to receiving device 1404 to indicate whether the PSSCH (e.g., PSSCH 1420 following discovery indication 1424) carries a discovery message and / or communication message. Discovery indication 1424 can be included in / sent in physical layer signaling. For example, transmitting device 1402 can send discovery indication 1424 in a physical-side walkway discovery indication channel, which indicates whether the PSSCH or PSCCH carries a discovery message. The physical-side walkway discovery indication channel can be in the same time slot as the PSSCH and / or PSCCH. The indication may include one or more of a source ID (e.g., for transmitting device 1402) or a destination ID (e.g., for receiving device 1404), such that receiving device 1404 can identify transmitting device 1402 at least partially based on the source ID and / or determine whether it is the recipient of the indication or communication / discovery message at least partially based on the destination ID. For example, one or more of the source ID or destination ID may be included in the PSFCH. In another example, the UE may transmit discovery indication 1424 in a physical-side walkway discovery indication channel in a time slot having the same structure as the time slot containing the PSFCH, and the physical-side walkway discovery indication channel may be transmitted in symbols for the PSFCH.

[0103] Transmitting device 1402 may use some PSFCH 1426 resources to signal (e.g., to indicate) that they will be used in the future to transmit discovery messages and / or communication messages on associated sub-channels (e.g., PSSCH 1420). Therefore, some of the scheduled PSFCHs (e.g., 1425) may be used to carry sidelink HARQ feedback (e.g., by receiving device 1404), for example, in conjunction with... Figure 9As described, some PSFCHs (e.g., 1426) can be used to carry discovery indication 1424 (e.g., by transmitting device 1402). In one example, the discovery indication 1424 transmitted within PSFCH 1426 can have an independent configuration relative to the configuration used for reporting side traverse feedback in PSFCH 1425. For example, the independent configuration can configure at least one of the period, number of symbols, or number of PRBs for the discovery indication 1424. In other words, the PSFCH resources used to indicate discovery messages can have an independent configuration (e.g., time slot, period, #RB, etc.) compared to those resources used for reporting side traverse feedback.

[0104] Then, at 1408, transmitting device 1402 may send a discovery message and / or communication message to receiving device 1404 based on discovery indication 1424. For example, if discovery indication 1424 in PSFCH 1426 indicates that transmitting device 1402 is sending a discovery message in PSSCH 1420, then transmitting device 1402 sends a discovery message in PSSCH 1420.

[0105] For receiving device 1404, as shown in 1410, receiving device 1404 can monitor or receive discovery indication 1424 from transmitting device 1402 in PSSCH 1426. In 1412, receiving device 1404 can determine whether PSSCH 1420 carries discovery messages and / or communication messages based on the received / monitored discovery indication 1424. In 1414, receiving device 1404 can monitor discovery messages and / or communications based on this determination. For example, if discovery indication 1424 indicates that transmitting device 1402 is sending a discovery message in PSSCH 1420, receiving device 1404 can monitor discovery messages in PSSCH 1420. However, if the indication indicates that PSSCH 1420 does not carry discovery messages, receiving device 1404 can exclude or skip monitoring discovery messages in PSSCH 1420 to reduce power consumption.

[0106] In another aspect of this disclosure, the aforementioned indications (e.g., 1106, 1206, 1306, 1406) may include multiple bits. For example, the transmitting device (e.g., 1102, 1202, 1302, 1402) may use multiple bits to additionally indicate the type of discovery message to be transmitted in the PSSCH, such as whether the discovery message is an announcement message in discovery model A (e.g., 706) or a solicitation message in discovery model B (e.g., 716).

[0107] Figure 15This is a flowchart 1500 of a wireless communication method. This method can be performed by a first wireless device communicating via a sidelink (e.g., UE 104, 402, 404, 406; transmitting devices 1102, 1202, 1302, 1402; device 310 or 350, RSU 407; apparatus 1602). Optional aspects are illustrated with dashed lines. This method can cause the first wireless device to indicate to a second wireless device whether the PSSCH carries a discovery message and / or a communication message.

[0108] In step 1502, the first wireless device can send an indication to the second wireless device, which in the physical layer signaling indicates whether the PSSCH carries a discovery message, for example, in conjunction with... Figure 11 to Figure 14 As described. For example, at 1106, transmitting device 1102 may send an indication to receiving device 1104 to indicate whether PSSCH 1120 carries a discovery message.

[0109] In one example, such as combination Figure 11 and Figure 12 As described, the first wireless device may transmit the indication in at least one of a first portion (e.g., SCI-1) or a second portion (e.g., SCI-2) of the SCI. For example, the first wireless device may transmit the first portion of the SCI in the PSCCH and the second portion of the SCI in the PSSCH. If the indication is transmitted in the first portion of the SCI, the first wireless device may transmit the indication in one or more reserved bits of the first portion of the SCI.

[0110] In one example, if the indication specifies that the PSSCH carries a discovery message, the first wireless device may send a discovery message in the PSSCH. Otherwise, if the indication specifies that the PSSCH does not carry a discovery message, the first wireless device may send a communication message in the PSSCH while sending a discovery message.

[0111] If the indication is sent in the second part of the SCI, in one example, the first wireless device may send the indication in one or more reserved or existing bits in the second part of the SCI. In another example, the indication may indicate whether the PSSCH carries a discovery message based on the PSCCH DMRS mapping or the PSCCH resource mapping. For example, a first mapping from the lowest PRB to the highest PRB may indicate that the PSSCH includes a discovery message, and a second mapping from the highest PRB to the lowest PRB may indicate that the PSSCH does not include a discovery message. Alternatively, a first mapping from the lowest PRB to the highest PRB may indicate that the PSSCH does not include a discovery message, and a second mapping from the highest PRB to the lowest PRB may indicate that the PSSCH includes a discovery message. In another example, the indication may indicate that the PSSCH does not carry a discovery message by mapping one or more PSCCH DMRS from the first DMRS symbol to the last DMRS symbol of one or more PSCCH DMRS, and the indication may indicate that the PSSCH carries a discovery message by mapping one or more PSCCH DMRS from the last DMRS symbol to the first DMRS symbol of one or more PSCCH DMRS. Alternatively, the indication can be used to indicate that the PSSCH carries a discovery message by mapping one or more PSCCH DMRS from the first DMRS symbol to the last DMRS symbol of one or more PSCCH DMRS, and the indication can be used to indicate that the PSSCH does not carry a discovery message by mapping one or more PSCCH DMRS from the last DMRS symbol to the first DMRS symbol of one or more PSCCH DMRS.

[0112] In another example, the indication can be based on a PSSCH DMRS mapping or a PSSCH resource mapping to indicate whether the PSSCH carries a discovery message. For example, a first mapping of the PSSCH from the lowest PRB to the highest PRB can indicate that the PSSCH carries a discovery message, and a second mapping of the PSSCH from the highest PRB to the lowest PRB can indicate that the PSSCH does not carry a discovery message. Alternatively, a first mapping of the PSSCH from the lowest PRB to the highest PRB can indicate that the PSSCH does not carry a discovery message, and a second mapping of the PSSCH from the highest PRB to the lowest PRB can indicate that the PSSCH carries a discovery message. In another example, if the second part of the SCI is sent via multiple PSSCH symbols, the indication can be based on mapping one or more PSSCH DMRS from the first PSSCH symbol carrying the second part of the SCI to the last PSSCH symbol carrying the second part of the SCI to indicate that the PSSCH does not carry a discovery message, and the indication can be based on mapping one or more PSSCH DMRS from the last PSSCH symbol carrying the second part of the SCI to the first PSSCH symbol carrying the second part of the SCI to indicate that the PSSCH carries a discovery message. Alternatively, if the second part of the SCI is transmitted via multiple PSSCH symbols, the indication can be made by mapping one or more PSSCH DMRS from the first PSSCH symbol carrying the second part of the SCI to the last PSSCH symbol carrying the second part of the SCI to indicate that the PSSCH carries a discovery message, and the indication can be made by mapping one or more PSSCH DMRS from the last PSSCH symbol carrying the second part of the SCI to the first PSSCH symbol carrying the second part of the SCI to indicate that the PSSCH does not carry a discovery message.

[0113] In another example, such as combination Figure 13As described, the first wireless device can transmit the indication in a physical-side walkway discovery indication channel, which indicates whether a subsequent PSSCH or PSCCH carries a discovery message. The physical-side walkway discovery indication channel can be a physical channel configured to carry information about an upcoming discovery message, for example, to notify the walkway device whether the discovery message will be included in the PSSCH transmission. The physical channel can be referred to by another name than the physical-side walkway discovery indication channel. The physical-side walkway discovery indication channel can include a source ID. The physical-side walkway discovery indication channel can optionally include a destination ID. For example, the source ID can inform the receiving device which device will send the discovery message. The destination ID can enable the receiving device to determine that it is the recipient of the discovery message and / or communication message, for example, if the discovery message will be a unicast message. The physical-side walkway discovery indication channel can include sequences; for example, the physical-side walkway discovery indication channel can be a sequence-based channel or a SCI-based channel. The first wireless device can transmit the physical-side walkway discovery indication channel in the same time slot as the PSSCH and / or PSCCH. For example, the physical-side walkway discovery indication channel can be different from the PSCCH and PSSCH. The physical-side walkway discovery indication channel can share one or more DMRSs with the PSSCH, or the discovery indication signal can include one or more DMRSs not shared with the PSSCH. Therefore, the physical-side walkway discovery indication channel can share the same sidewalk resource pool as discovery messages and communication messages, and the physical-side walkway discovery indication channel can use resources that do not conflict with one or more demodulation reference signals (DMRSs) of the PSSCH or PSCCH for the physical-side walkway discovery indication channel. In another example, the physical-side walkway discovery indication channel can be configured to be associated with the PSCCH or PSSCH carrying the discovery message, such that the presence of the discovery indication signal indicates that the discovery message will be sent in the PSCCH or PSSCH. Furthermore, the physical-side walkway discovery indication channel can include information indicating whether a discovery message will be sent or not. Optionally, the physical-side walkway discovery indication channel may further include one or more reference signals for performing at least one of time tracking, frequency tracking, or Doppler estimation against the PSCCH or PSSCH, and the one or more reference signals may also be used to perform mobility management or radio link monitoring. In some examples, transmitting the indication at 1502 may include transmitting the indication in the physical-side walkway discovery indication channel in a time slot having the same structure as the time slot containing the PSFCH, and the physical-side walkway discovery indication channel being transmitted in symbols of the PSFCH.

[0114] In another example, such as combination Figure 14As described, the first wireless device can transmit the indication in the PSFCH, wherein the indication can indicate an associated subchannel for transmitting discovery messages. The first wireless device can transmit one or more of a source ID or a destination ID in the PSFCH. The indication within the PSFCH can have an independent configuration relative to the configuration used for reporting side-link feedback within the PSFCH. For example, the independent configuration can configure at least one of the following: the period of the indication, the number of symbols, or the number of PRBs.

[0115] The above indication may include multiple bits. The indication may also indicate the type of discovery message. For example, the indication may indicate whether the discovery message is an announcement message or a solicitation message.

[0116] In 1504, the first wireless device can transmit PSSCH at least in part based on this instruction, for example, in combination with Figure 11 to Figure 14 As described. For example, at 1108, transmitting device 1102 may send a discovery message and / or a communication message to receiving device 1104 based on the indication. For instance, as illustrated at 1506, the first wireless device may send the indication in physical layer signaling, indicating that the PSSCH carries a discovery message, and as illustrated at 1510, sending the PSSCH at 1504 may include sending the discovery message in the PSSCH. In another example, as illustrated at 1508, the indication in physical layer signaling may indicate that the PSSCH does not carry a discovery message, and as illustrated at 1512, the first wireless device may send the PSSCH at 1504 including sending a communication message in the PSSCH.

[0117] Figure 16 This is a schematic diagram illustrating an example of the hardware implementation of device 1602. Figure 1600. Device 1602 is a UE and includes a cellular baseband processor 1604 (also referred to as a modem) coupled to a cellular RF transceiver 1622 and one or more Subscriber Identity Module (SIM) cards 1620, an application processor 1606 coupled to a Secure Digital (SD) card 1608 and a screen 1610, a Bluetooth module 1612, a Wireless Local Area Network (WLAN) module 1614, a Global Positioning System (GPS) module 1616, and a power supply 1618. The cellular baseband processor 1604 communicates with the UE 104 and / or BS 102 / 180 via the cellular RF transceiver 1622. The cellular baseband processor 1604 may include a computer-readable storage medium / memory. The computer-readable storage medium / memory may be non-transitory. The cellular baseband processor 1604 is responsible for general processing, including executing software stored on the computer-readable storage medium / memory. When executed by the cellular baseband processor 1604, this software causes the cellular baseband processor 1604 to perform the various functions described above. Computer-readable storage media / memory can also be used to store data manipulated by the cellular baseband processor 1604 during software execution. The cellular baseband processor 1604 further includes a receiving component 1630, a communication manager 1632, and a transmitting component 1634. The communication manager 1632 includes one or more of the described components. The components within the communication manager 1632 can be stored in a computer-readable storage medium / memory and / or configured as hardware within the cellular baseband processor 1604. The cellular baseband processor 1604 can be a component of device 350 and can include memory 360 and / or at least one of TX processor 368, RX processor 356, and controller / processor 359. In one configuration, device 1602 can be a modem chip and includes only the baseband processor 1604, while in another configuration, device 1602 can be the entire wireless device (e.g., see...). Figure 3 (350), and includes an additional module of device 1602.

[0118] Communication manager 1632 includes indication component 1640, which is configured to send an indication to a second wireless device in physical layer signaling, indicating whether the PSSCH carries a discovery message, for example, as in combination with Figure 15 As described in 1502. The communication manager 1632 further includes a discovery communication message component 1642, which is configured to send PSSCH (e.g., including discovery messages or communication messages) at least in part based on the indication, for example, as in combination with... Figure 15 As described in 1504.

[0119] The device may include the ability to perform the above-described actions. Figure 15 The additional components of each box in the flowchart of the algorithm. Therefore, the aforementioned Figure 15Each block in the flowchart can be executed by a component, and the apparatus can include one or more of these components. These components can be one or more hardware components specifically configured to execute the process / algorithm, implemented by a processor configured to execute the process / algorithm, stored in a computer-readable storage medium for processor implementation, or some combination thereof.

[0120] In one configuration, apparatus 1602, particularly cellular baseband processor 1604, includes units (e.g., indication component 1640) for sending an indication to a second wireless device, the indication indicating in physical layer signaling whether the PSSCH carries a discovery message. Apparatus 1602 includes units (e.g., discovery communication message component 1642, transmission component 1634) for sending the PSSCH (e.g., including a discovery message or a communication message) at least in part based on the indication.

[0121] In one configuration, device 1602 may transmit the indication in at least one of a first portion (e.g., SCI-1) or a second portion (e.g., SCI-2) of the SCI. In this configuration, device 1602 may transmit the first portion of the SCI in the PSCCH and the second portion in the PSSCH. If the indication is transmitted in the first portion of the SCI, device 1602 may transmit the indication in one or more reserved bits within the first portion of the SCI.

[0122] In one configuration, if the indication is sent in the second part of the SCI, device 1602 may send the indication in one or more reserved or existing bits of the second part of the SCI. In another configuration, the indication may indicate whether the PSSCH carries a discovery message based on a PSCCH DMRS mapping or a PSCCH resource mapping. In such a configuration, a first mapping from the lowest PRB to the highest PRB may indicate that the PSSCH includes a discovery message, while a second mapping from the highest PRB to the lowest PRB may indicate that the PSSCH does not include a discovery message. Alternatively, a first mapping from the lowest PRB to the highest PRB may indicate that the PSSCH does not include a discovery message, while a second mapping from the highest PRB to the lowest PRB may indicate that the PSSCH includes a discovery message. In another configuration, the indication may indicate that the PSSCH does not carry a discovery message by mapping one or more PSCCH DMRS from a first DMRS symbol to the last DMRS symbol of one or more PSCCH DMRS, and the indication may indicate that the PSSCH carries a discovery message by mapping one or more PSCCH DMRS from the last DMRS symbol to the first DMRS symbol of one or more PSCCH DMRS. Alternatively, the indication can be used to indicate that the PSSCH carries a discovery message by mapping one or more PSCCH DMRS from the first DMRS symbol to the last DMRS symbol of one or more PSCCH DMRS, and the indication can be used to indicate that the PSSCH does not carry a discovery message by mapping one or more PSCCH DMRS from the last DMRS symbol to the first DMRS symbol of one or more PSCCH DMRS.

[0123] In another configuration, the indication can be based on either the PSSCH DMRS mapping or the PSSCH resource mapping to indicate whether the PSSCH carries a discovery message. In this configuration, a first mapping of the PSSCH from the lowest PRB to the highest PRB can indicate that the PSSCH carries a discovery message, while a second mapping of the PSSCH from the highest PRB to the lowest PRB can indicate that the PSSCH does not carry a discovery message. Alternatively, a first mapping of the PSSCH from the lowest PRB to the highest PRB can indicate that the PSSCH does not carry a discovery message, while a second mapping of the PSSCH from the highest PRB to the lowest PRB can indicate that the PSSCH carries a discovery message. In another configuration, if the second part of the SCI is transmitted via multiple PSSCH symbols, the indication can be made by mapping one or more PSSCH DMRS from the first PSSCH symbol carrying the second part of the SCI to the last PSSCH symbol carrying the second part of the SCI to indicate that the PSSCH does not carry a discovery message, and by mapping one or more PSSCH DMRS from the last PSSCH symbol carrying the second part of the SCI to the first PSSCH symbol carrying the second part of the SCI to indicate that the PSSCH carries a discovery message. Alternatively, if the second part of the SCI is transmitted via multiple PSSCH symbols, the indication can be made by mapping one or more PSSCH DMRS from the first PSSCH symbol carrying the second part of the SCI to the last PSSCH symbol carrying the second part of the SCI to indicate that the PSSCH carries a discovery message, and by mapping one or more PSSCH DMRS from the last PSSCH symbol carrying the second part of the SCI to the first PSSCH symbol carrying the second part of the SCI to indicate that the PSSCH does not carry a discovery message.

[0124] In another configuration, device 1602 may transmit an indication in a discovery indication signal, which indicates whether a subsequent PSSCH or PSCCH carries a discovery message. The discovery indication signal may include a sequence. Device 1602 may transmit the discovery indication signal in the same time slot as the PSSCH and / or PSCCH. Device 1602 may also transmit the discovery indication signal on a different physical channel than the PSCCH and PSSCH. The discovery indication signal may share one or more DMRSs with the PSSCH, or the discovery indication signal may include one or more DMRSs not shared with the PSSCH. Therefore, the discovery indication signal may share the same sidelink resource pool as the discovery message and the communication message, and the discovery indication signal may not use resources that conflict with one or more DMRSs of the PSSCH or PSCCH. In another configuration, the discovery indication signal may be configured to be associated with a PSCCH or PSSCH carrying a discovery message, such that the presence of the discovery indication signal indicates that a discovery message will be transmitted in the PSCCH or PSSCH. Furthermore, the discovery indication signal may include information indicating whether a discovery message will be transmitted or will not be transmitted. Optionally, the discovery indication signal may further include one or more reference signals for performing at least one of time tracking, frequency tracking, or Doppler estimation for PSCCH or PSSCH decoding, and the one or more reference signals may also be used to perform mobility management or radio link monitoring.

[0125] In another configuration, device 1602 can transmit an indication in the PSFCH, wherein the indication may indicate an associated subchannel for transmitting a discovery message. This indication within the PSFCH may have an independent configuration relative to the configuration for reporting side-link feedback within the PSFCH. In this configuration, the independent configuration configures at least one of the following: the period, the number of symbols, or the number of PRBs for the indication.

[0126] The above indication may include multiple bits. The indication may also indicate the type of discovery message. For example, the indication may indicate whether the discovery message is an announcement message or a solicitation message.

[0127] The aforementioned unit may be one or more of the components of device 1602 configured to perform the functions described above. As described above, device 1602 may include TX processor 368, RX processor 356, and controller / processor 359. Therefore, in one configuration, the aforementioned unit may be TX processor 368, RX processor 356, and controller / processor 359, configured to perform the functions described above.

[0128] Figure 17This is a flowchart 1700 of a wireless communication method. This method can be performed by a first wireless device communicating via a sidelink (e.g., UE 104, 402, 404, 406; receiving devices 1104, 1204, 1304, 1404; device 310 or 350, RSU 407; apparatus 1802). Optional aspects are illustrated with dashed lines. This method enables the first wireless device to monitor discovery messages or communication messages on a designated PSSCH to achieve power savings.

[0129] At 1702, the first wireless device receives an indication from the second wireless device, which in the physical layer signaling indicates whether the PSSCH carries a discovery message, for example, in conjunction with... Figure 11 to Figure 14 As described. For example, in 1110, receiving device 1104 can monitor an indication from transmitting device 1102 indicating whether the PSSCH carries a discovery message.

[0130] In one example, such as combination Figure 11 and Figure 12 As described, the first wireless device may receive the indication in at least one of the first part of the SCI in the PSCCH or the second part of the SCI in the PSSCH. If the indication is received in the first part of the SCI, the first wireless device may receive the indication in one or more reserved bits of the first part of the SCI.

[0131] If the indication is received in the second part of the SCI, in one example, the first wireless device may receive the indication in one or more reserved or existing bits of the second part of the SCI. In another example, the indication may indicate whether the PSSCH carries a discovery message based on the PSCCH DMRS mapping or the PSCCH resource mapping. For example, a first mapping from the lowest PRB to the highest PRB may indicate that the PSSCH includes a discovery message, while a second mapping from the highest PRB to the lowest PRB may indicate that the PSSCH does not include a discovery message. Alternatively, a first mapping from the lowest PRB to the highest PRB may indicate that the PSSCH does not include a discovery message, while a second mapping from the highest PRB to the lowest PRB may indicate that the PSSCH includes a discovery message. In another example, the indication may indicate that the PSSCH does not carry a discovery message by mapping one or more PSCCH DMRS from the first DMRS symbol to the last DMRS symbol of one or more PSCCH DMRS, and the indication may indicate that the PSSCH carries a discovery message by mapping one or more PSCCH DMRS from the last DMRS symbol to the first DMRS symbol of one or more PSCCH DMRS. Alternatively, the indication can indicate that the PSSCH carries a discovery message by mapping one or more PSCCH DMRS from the first DMRS symbol to the last DMRS symbol of one or more PSCCH DMRS, and the indication can indicate that the PSSCH does not carry a discovery message by mapping one or more PSCCH DMRS from the last DMRS symbol to the first DMRS symbol of one or more PSCCH DMRS.

[0132] In another example, the indication can be based on a PSSCH DMRS mapping or a PSSCH resource mapping to indicate whether the PSSCH carries a discovery message. For example, a first mapping of the PSSCH from the lowest PRB to the highest PRB can indicate that the PSSCH carries a discovery message, while a second mapping of the PSSCH from the highest PRB to the lowest PRB can indicate that the PSSCH does not carry a discovery message. Alternatively, a first mapping of the PSSCH from the lowest PRB to the highest PRB can indicate that the PSSCH does not carry a discovery message, while a second mapping of the PSSCH from the highest PRB to the lowest PRB can indicate that the PSSCH carries a discovery message. In another example, if the second part of the SCI is sent via multiple PSSCH symbols, the indication can be made by mapping one or more PSSCH DMRS from the first PSSCH symbol carrying the second part of the SCI to the last PSSCH symbol carrying the second part of the SCI to indicate that the PSSCH does not carry a discovery message, and the indication can be made by mapping one or more PSSCH DMRS from the last PSSCH symbol carrying the second part of the SCI to the first PSSCH symbol carrying the second part of the SCI to indicate that the PSSCH carries a discovery message. Alternatively, if the second part of the SCI is transmitted via multiple PSSCH symbols, the indication can be made by mapping one or more PSSCH DMRS from the first PSSCH symbol carrying the second part of the SCI to the last PSSCH symbol carrying the second part of the SCI to indicate that the PSSCH carries a discovery message, and the indication can be made by mapping one or more PSSCH DMRS from the last PSSCH symbol carrying the second part of the SCI to the first PSSCH symbol carrying the second part of the SCI to indicate that the PSSCH does not carry a discovery message.

[0133] In another example, such as combination Figure 13 As described, the first wireless device can receive the indication in the physical-side cross-link discovery indication channel, which indicates whether the PSSCH or subsequent PSCCH carries a discovery message. (As in conjunction with...) Figure 15The physical channels discussed may be referred to by different names. The discovery indication signal may include sequences; for example, a physical-side walkway discovery indication channel may be sequence-based or SCI-based. A first radio device may receive the physical-side walkway discovery indication channel in the same time slot as the PSSCH and / or PSCCH. A first radio device may receive the physical-side walkway discovery indication channel on a physical channel different from the PSCCH and PSSCH. The physical-side walkway discovery indication channel may share one or more DMRSs with the PSSCH, or it may include one or more DMRSs not shared with the PSSCH. Therefore, the physical-side walkway discovery indication channel may share the same side-walkway resource pool as discovery messages and communication messages, and the discovery indication signal may not use resources that conflict with one or more DMRSs of the PSSCH or PSCCH. In another example, the physical-side walkway discovery indication channel may be associated with a PSCCH or PSSCH carrying a discovery message, such that the presence of the physical-side walkway discovery indication channel indicates that a discovery message will be transmitted in the PSCCH or PSSCH. In addition, the physical-side link discovery indication channel may include information indicating whether a discovery message will be sent or not.

[0134] Optionally, the physical-side link discovery indication channel may further include one or more reference signals for performing at least one of time tracking, frequency tracking, or Doppler estimation for the PSCCH or PSSCH. The one or more reference signals may also be used to perform mobility management or radio link monitoring.

[0135] In another example, such as combination Figure 14 As described, the first wireless device can monitor the indication in the PSFCH, where the indication can indicate the associated subchannel for transmitting discovery messages. The indication within the PSFCH can have an independent configuration relative to the configuration used for reporting side-link feedback within the PSFCH. For example, the independent configuration can configure at least one of the following: the period of the indication, the number of symbols, or the number of PRBs.

[0136] The above indication may include multiple bits. The indication may also indicate the type of discovery message. For example, it may indicate whether the discovery message is an announcement or a solicitation message.

[0137] In 1704, the first wireless device can determine whether the PSSCH carries a discovery message, for example, by combining... Figure 11 to Figure 14 As described. For example, in 1112, receiving device 1104 can determine whether the PSSCH carries a discovery message.

[0138] In 1706, if the first wireless device receives the indication and the indication indicates that the PSSCH carries a discovery message, then the first wireless device can decode the discovery message in the PSSCH, for example, by combining... Figure 11 to Figure 14 As described. For example, at 1114, if receiving device 1104 receives the indication and the indication indicates that the PSSCH carries a discovery message, then receiving device 1104 can monitor or decode the discovery message in the PSSCH. In some examples, at 1702, the indication in physical layer signaling can indicate that the PSSCH carries a discovery message, and at 1706, the first wireless device can decode the discovery message in the PSSCH in response to receiving the indication. In other examples, the indication in physical layer signaling can indicate at 1702 that the PSSCH does not carry a discovery message, and the first wireless device can skip decoding the PSSCH at 1708 in response to receiving the indication.

[0139] Figure 18Schematic diagram 1800 illustrates an example of the hardware implementation of device 1802. Device 1802 is a UE and includes a cellular baseband processor 1804 (also referred to as a modem) coupled to a cellular RF transceiver 1822 and one or more Subscriber Identity Module (SIM) cards 1820, an application processor 1806 coupled to a Secure Digital Card (SD) card 1808 and a screen 1810, a Bluetooth module 1812, a Wireless Local Area Network (WLAN) module 1814, a Global Positioning System (GPS) module 1816, and a power supply 1818. The cellular baseband processor 1804 communicates with UE 104 and / or BS 102 / 180 via the cellular RF transceiver 1822. The cellular baseband processor 1804 may include a computer-readable storage medium / memory. The computer-readable storage medium / memory may be non-transitory. The cellular baseband processor 1804 is responsible for general processing, including executing software stored on the computer-readable storage medium / memory. When executed by the cellular baseband processor 1804, the software causes the cellular baseband processor 1804 to perform the various functions described above. The computer-readable storage medium / memory can also be used to store data manipulated by the cellular baseband processor 1804 during software execution. The cellular baseband processor 1804 further includes a receiving component 1830, a communication manager 1832, and a transmitting component 1834. The communication manager 1832 includes one or more of the illustrated components. The components within the communication manager 1832 can be stored in a computer-readable storage medium / memory and / or configured as hardware within the cellular baseband processor 1804. The cellular baseband processor 1804 can be a component of device 350 and can include memory 360 and / or at least one of TX processor 368, RX processor 356, and controller / processor 359. In one configuration, device 1802 can be a modem chip and includes only the baseband processor 1804, while in another configuration, device 1802 can be the entire wireless device (e.g., see...). Figure 3 (350), and includes an additional module of device 1802.

[0140] Communication manager 1832 includes indication monitoring component 1840, which is configured to receive indication from a second wireless device indicating in physical layer signaling whether the PSSCH carries a discovery message, for example, as combined with Figure 17 As described in 1702. The communication manager 1832 further includes a determining component 1842 configured to determine whether the PSSCH carries a discovery message, for example, as in conjunction with... Figure 17 As described in 1704. The communication manager 1832 further includes a discovery message decoding component 1844, which is configured to decode the discovery message in the PSSCH if the indication indicates that the PSSCH carries a discovery message, for example, as in conjunction with... Figure 17As described in 1706.

[0141] The device may include the ability to perform the above-described actions. Figure 17 The additional components of each box in the flowchart of the algorithm. Therefore, the aforementioned Figure 17 Each box in the flowchart can be executed by a component, and the apparatus can include one or more of these components. A component can be one or more hardware components specifically configured to execute the process / algorithm, implemented by a processor configured to execute the process / algorithm, stored in a computer-readable storage medium for processor implementation, or some combination thereof.

[0142] In one configuration, device 1802 (particularly cellular baseband processor 1804) includes a unit for receiving an indication (e.g., indication monitoring component 1840) from a second wireless device, the indication indicating whether the PSSCH carries a discovery message. Device 1802 includes a unit for determining whether the PSSCH carries a discovery message (e.g., determination component 1842). Device 1802 includes a unit for decoding the discovery message in the PSSCH if the indication indicates that the PSSCH carries a discovery message (e.g., discovery message decoding component 1844).

[0143] In one configuration, device 1802 may receive the indication in at least one of a first portion or a second portion of the SCI, wherein device 1802 may receive the first portion of the SCI in the PSCCH and monitor the second portion of the SCI in the PSSCH. If the indication is received in the first portion of the SCI, device 1802 may receive the indication in one or more reserved bits of the first portion of the SCI.

[0144] If the indication is received in the second part of the SCI, in one configuration, device 1802 may receive the indication in one or more reserved or existing bits of the second part of the SCI. In another configuration, the indication may indicate whether the PSSCH carries a discovery message based on a PSCCH DMRS mapping or a PSCCH resource mapping. In such a configuration, a first mapping from the lowest PRB to the highest PRB may indicate that the PSSCH includes a discovery message, while a second mapping from the highest PRB to the lowest PRB may indicate that the PSSCH does not include a discovery message. Alternatively, a first mapping from the lowest PRB to the highest PRB may indicate that the PSSCH does not include a discovery message, while a second mapping from the highest PRB to the lowest PRB may indicate that the PSSCH includes a discovery message. In another configuration, the indication may indicate that the PSSCH does not carry a discovery message by mapping one or more PSCCH DMRS from a first DMRS symbol to the last DMRS symbol of one or more PSCCH DMRS, and the indication may indicate that the PSSCH carries a discovery message by mapping one or more PSCCH DMRS from the last DMRS symbol to the first DMRS symbol of one or more PSCCH DMRS. Alternatively, the indication can be made by mapping one or more PSCCH DMRS from the first DMRS symbol to the last DMRS symbol of one or more PSCCH DMRS to indicate that the PSSCH carries a discovery message, and the indication can be made by mapping one or more PSCCH DMRS from the last DMRS symbol to the first DMRS symbol of one or more PSCCH DMRS to indicate that the PSSCH does not carry a discovery message.

[0145] In another configuration, the indication can be based on a PSSCH DMRS mapping or a PSSCH resource mapping to indicate whether the PSSCH carries a discovery message. In this configuration, a first mapping of the PSSCH from the lowest PRB to the highest PRB can indicate that the PSSCH carries a discovery message, while a second mapping of the PSSCH from the highest PRB to the lowest PRB can indicate that the PSSCH does not carry a discovery message. Alternatively, a first mapping of the PSSCH from the lowest PRB to the highest PRB can indicate that the PSSCH does not carry a discovery message, while a second mapping of the PSSCH from the highest PRB to the lowest PRB can indicate that the PSSCH carries a discovery message. In another configuration, if the second part of the SCI is sent via multiple PSSCH symbols, the indication can be based on mapping one or more PSSCH DMRS from the first PSSCH symbol carrying the second part of the SCI to the last PSSCH symbol carrying the second part of the SCI to indicate that the PSSCH does not carry a discovery message, and the indication can be based on mapping one or more PSSCH DMRS from the last PSSCH symbol carrying the second part of the SCI to the first PSSCH symbol carrying the second part of the SCI to indicate that the PSSCH carries a discovery message. Alternatively, if the second part of the SCI is transmitted via multiple PSSCH symbols, the indication can be made by mapping one or more PSSCH DMRS from the first PSSCH symbol carrying the second part of the SCI to the last PSSCH symbol carrying the second part of the SCI to indicate that the PSSCH carries a discovery message, and the indication can be made by mapping one or more PSSCH DMRS from the last PSSCH symbol carrying the second part of the SCI to the first PSSCH symbol carrying the second part of the SCI to indicate that the PSSCH does not carry a discovery message.

[0146] In another configuration, device 1802 can monitor the indication in a discovery indication signal, which indicates whether a discovery message is carried on the PSSCH or subsequent PSCCH. The discovery indication signal includes a sequence. Device 1802 can monitor the discovery indication signal in the same time slot as the PSSCH and / or PSCCH. Device 1802 can also monitor the discovery indication signal on a different physical channel than the PSCCH and PSSCH. The discovery indication signal may share one or more DMRSs with the PSSCH, or it may include one or more DMRSs not shared with the PSSCH. Therefore, the discovery indication signal may share the same sidelink resource pool as the discovery message and the communication message, and it may not use resources that conflict with one or more DMRSs of the PSSCH or PSCCH. In another configuration, the discovery indication signal can be associated with a PSCCH or PSSCH carrying a discovery message, such that the presence of the discovery indication signal indicates that a discovery message will be sent on the PSCCH or PSSCH. Furthermore, the discovery indication signal may include information indicating whether a discovery message will be sent or will not be sent.

[0147] Optionally, the discovery indication signal may further include one or more reference signals for performing at least one of time tracking, frequency tracking, or Doppler estimation for PSCCH or PSSCH decoding. The one or more reference signals may also be used to perform mobility management or radio link monitoring.

[0148] In another configuration, device 1802 can monitor the indication in the PSFCH, where the indication can indicate the associated subchannel used to send discovery messages. The indication within the PSFCH can have an independent configuration relative to the configuration used for reporting side-link feedback within the PSFCH. In this configuration, the independent configuration can configure at least one of the following: the period, the number of symbols, or the number of PRBs for the indication.

[0149] The above indication may include multiple bits. It may also indicate the type of discovery message. For configuration purposes, this indication may specify whether the discovery message is an announcement or a solicitation message.

[0150] The aforementioned unit may be one or more of the aforementioned components of device 1802, configured to perform the functions described in the aforementioned unit. As described above, device 1802 may include TX processor 368, RX processor 356, and controller / processor 359. Therefore, in one configuration, the aforementioned unit may be TX processor 368, RX processor 356, and controller / processor 359 configured to perform the functions described in the aforementioned unit.

[0151] The aspects proposed herein can improve resource allocation for side-link communication and reduce power consumption at the receiving-side and / or transmitting-side traversal devices when performing the side-link discovery process. In one aspect of this disclosure, the transmitting-side traversal device can indicate to the receiving-side traversal device whether the PSSCH carries a discovery message and / or a communication message. In response, when the PSSCH carries a discovery message and / or a communication message, the receiving-side traversal device can monitor the PSSCH; when the PSSCH does not carry a discovery message and / or a communication message, the receiving-side traversal device can skip monitoring the PSSCH.

[0152] The following aspects are illustrative only and may be combined with, but not limited to, other aspects or teachings described herein.

[0153] Aspect 1 is a wireless communication method at a first wireless device, comprising: sending an indication to a second wireless device indicating whether a PSSCH carries a discovery message; and sending a discovery message or a communication message in the PSSCH based at least in part on the indication.

[0154] In aspect 2, the method of aspect 1 further includes: the first wireless device transmitting an instruction in at least one of the first part or the second part of the SCI.

[0155] In aspect 3, the method of aspect 1 or aspect 2 further includes: the first wireless device transmitting a first portion of the SCI in the PSCCH and transmitting a second portion of the SCI in the PSSCH.

[0156] In aspect 4, the method of any one of aspects 1-3 further comprises: the first wireless device transmitting an indication in one or more reserved bits in the first part of the SCI.

[0157] In aspect 5, the method of any one of aspects 1-2 and 4 further includes: the first wireless device transmitting an instruction in the second part of the SCI.

[0158] In aspect 6, the method of any one of aspects 1-2 and 4-5 further comprises: the first wireless device transmitting an indication in one or more reserved or existing bits in the second part of the SCI.

[0159] In aspect 7, the method of any one of aspects 1-6 further comprises: the indication indicating whether the PSSCH carries a discovery message based on the PSCCHDMRS mapping or the PSCCH resource mapping.

[0160] In aspect 8, the method of any one of aspects 1-7 further comprises: a first mapping indication PSSCH from the lowest PRB to the highest PRB including a discovery message, while a second mapping indication PSSCH from the highest PRB to the lowest PRB does not include a discovery message.

[0161] In aspect 9, the method of any one of aspects 1-7 further comprises: a first mapping from the lowest PRB to the highest PRB indicating that the PSSCH does not include discovery messages, while a second mapping from the highest PRB to the lowest PRB indicating that the PSSCH includes discovery messages.

[0162] In aspect 10, the method of any one of aspects 1-9 further comprises: the indication indicating that the PSSCH does not carry a discovery message by mapping one or more PSCCH DMRS from a first DMRS symbol to the last DMRS symbol of one or more PSCCH DMRS, and the indication indicating that the PSSCH carries a discovery message by mapping one or more PSCCH DMRS from the last DMRS symbol to the first DMRS symbol of one or more PSCCH DMRS.

[0163] In aspect 11, the method of any one of aspects 1-9 further comprises: the indication indicating that the PSSCH carries a discovery message by mapping one or more PSCCH DMRS from a first DMRS symbol to the last DMRS symbol of one or more PSCCH DMRS, and the indication indicating that the PSSCH does not carry a discovery message by mapping one or more PSCCH DMRS from the last DMRS symbol to the first DMRS symbol of one or more PSCCH DMRS.

[0164] In aspect 12, the method of any one of aspects 1-11 further comprises: the indication based on the PSSCHDMRS mapping or the PSSCH resource mapping indicating that the PSSCH carries a discovery message.

[0165] In aspect 13, the method of any one of aspects 1-12 further includes: a first mapping of the PSSCH from the lowest PRB to the highest PRB indicating that the PSSCH carries a discovery message, and a second mapping of the PSSCH from the highest PRB to the lowest PRB indicating that the PSSCH does not carry a discovery message.

[0166] In aspect 14, the method of any one of aspects 1-12 further comprises: a first mapping of PSSCH from the lowest PRB to the highest PRB indicating that PSSCH does not carry a discovery message, and a second mapping of PSSCH from the highest PRB to the lowest PRB indicating that PSSCH carries a discovery message.

[0167] In aspect 15, the method of any one of aspects 1-14 further comprises: if the second part of the SCI is transmitted via a plurality of PSSCH symbols, the indication indicates that the PSSCH does not carry a discovery message by mapping one or more PSSCH DMRS from the first PSSCH symbol carrying the second part of the SCI to the last PSSCH symbol carrying the second part of the SCI, and the indication indicates that the PSSCH carries a discovery message by mapping one or more PSSCH DMRS from the last PSSCH symbol carrying the second part of the SCI to the first PSSCH symbol carrying the second part of the SCI.

[0168] In aspect 16, the method of any one of aspects 1-14 further comprises: if the second part of the SCI is transmitted on a plurality of PSSCH symbols, the indication indicates that the PSSCH carries a discovery message by mapping one or more PSSCH DMRS from the first PSSCH symbol carrying the second part of the SCI to the last PSSCH symbol carrying the second part of the SCI, and the indication indicates that the PSSCH does not carry a discovery message by mapping one or more PSSCH DMRS from the last PSSCH symbol carrying the second part of the SCI to the first PSSCH symbol carrying the second part of the SCI.

[0169] In aspect 17, the method of any one of aspects 1-16 further comprises: a first wireless device transmitting an indication in a discovery indication signal, the indication indicating whether a PSSCH or a subsequent PSCCH carries a discovery message.

[0170] In aspect 18, the method of any one of aspects 1-17 further includes: detecting that the indicator signal comprises a sequence.

[0171] In aspect 19, the method of any one of aspects 1-18 further comprises: the first wireless device transmitting a discovery indication signal in the same time slot as PSSCH and PSCCH.

[0172] In aspect 20, the method of any one of aspects 1-18 further comprises: a first wireless device transmitting a discovery indication signal on a physical channel different from the PSCCH and PSSCH.

[0173] In aspect 21, the method of any one of aspects 1-20 further comprises: the discovery indication signal sharing one or more DMRS with the PSSCH or the discovery indication signal including one or more DMRS.

[0174] In aspect 22, the method of any one of aspects 1-21 further comprises: the discovery indication signal sharing the same sidelink resource pool as the discovery message and the communication message, and the discovery indication signal not using resources that conflict with one or more DMRS of the PSSCH or PSCCH.

[0175] In aspect 23, the method of any one of aspects 1-22 further comprises: a discovery indication signal being associated with a PSCCH or PSSCH carrying a discovery message, and the presence of the discovery indication signal indicating that a discovery message will be sent in the PSCCH or PSSCH.

[0176] In aspect 24, the method of any one of aspects 1-23 further includes: the discovery indication signal includes information indicating that a discovery message will be sent or that a discovery message will not be sent.

[0177] In aspect 25, the method of any one of aspects 1-24 further comprises: the discovery indication signal comprising one or more reference signals for performing at least one of time tracking, frequency tracking or Doppler estimation for PSCCH or PSSCH decoding.

[0178] In aspect 26, the method of any one of aspects 1-25 further includes: the detection indication signal including one or more reference signals for performing mobility management or radio link monitoring.

[0179] In aspect 27, the method of any one of aspects 1-26 further includes: the first wireless device transmitting an instruction in the PSFCH.

[0180] In aspect 28, the method of any one of aspects 1-27 further includes: the indication indicating an associated subchannel for sending a discovery message.

[0181] In aspect 29, the method of any one of aspects 1-28 further comprises: the indication within the PSFCH having an independent configuration relative to the configuration for reporting side-link feedback within the PSFCH.

[0182] In aspect 30, the method of any one of aspects 1-29 further includes at least one of the period, number of symbols, or number of PRBs of the independent configuration configuration indication.

[0183] In aspect 31, the method of any one of aspects 1-30 further includes: the indication comprising a plurality of bits.

[0184] In aspect 32, the method of any one of aspects 1-31 further includes: the indication indicating the type of the discovery message.

[0185] In aspect 33, the method of any one of aspects 1-32 further includes: the type of discovery message includes an announcement message or a solicitation message.

[0186] Aspect 34 is an apparatus for wireless communication, comprising: a unit for transmitting an indication to a second wireless device, the indication indicating whether a PSSCH carries a discovery message; and a unit for transmitting a discovery message or a communication message in the PSSCH based at least in part on the indication.

[0187] In aspect 35, the apparatus of aspect 34 further includes: a unit for performing the method of any one of aspects 2-33.

[0188] Aspect 36 is an apparatus for wireless communication, comprising: a memory; and at least one processor coupled to the memory, the memory and the at least one processor being configured to perform the methods of aspects 1-33.

[0189] Aspect 37 is a non-transitory computer-readable storage medium storing computer-executable code for wireless communication at a first wireless device, which, when executed by a processor, causes the processor to perform the method described in any one of aspects 1-33.

[0190] Aspect 38 is a method of wireless communication at a first wireless device, comprising: monitoring an indication from a second wireless device indicating whether a PSSCH carries a discovery message; determining whether the PSSCH carries a discovery message; and if the first wireless device receives the indication and the indication indicates that the PSSCH carries a discovery message, monitoring the discovery message in the PSSCH.

[0191] In aspect 39, the method of aspect 38 further includes: a first wireless device monitoring the indication in at least one of a first portion or a second portion of the SCI.

[0192] In aspect 40, the method of aspect 38 or aspect 39 further includes: a first wireless device monitoring a first portion of the SCI in the PSCCH and monitoring a second portion of the SCI in the PSSCH.

[0193] In aspect 41, the method of any one of aspects 38-40 further comprises: the first wireless device monitoring the indication in one or more reserved bits of the first portion of the SCI.

[0194] In aspect 42, the method of any one of aspects 38-41 further includes: the first wireless device monitoring the indication in the second part of the SCI.

[0195] In aspect 43, the method of any one of aspects 38-42 further comprises: the first wireless device monitoring the indication in one or more reserved bits or existing bits of the second part of the SCI.

[0196] In aspect 44, the method of any one of aspects 38-43 further comprises: the indication indicating whether the PSSCH carries a discovery message based on the PSCCHDMRS mapping or the PSCCH resource mapping.

[0197] In aspect 45, the method of any one of aspects 38-44 further comprises: a first mapping indication PSSCH from the lowest PRB to the highest PRB including a discovery message, while a second mapping indication PSSCH from the highest PRB to the lowest PRB does not include a discovery message.

[0198] In aspect 46, the method of any one of aspects 38-44 further comprises: a first mapping from the lowest PRB to the highest PRB indicating that the PSSCH does not include a discovery message, while a second mapping from the highest PRB to the lowest PRB indicating that the PSSCH includes a discovery message.

[0199] In aspect 47, the method of any one of aspects 38-46 further comprises: the indication indicating that the PSSCH does not carry a discovery message by mapping one or more PSCCH DMRS from a first DMRS symbol to the last DMRS symbol of one or more PSCCH DMRS, and the indication indicating that the PSSCH carries a discovery message by mapping one or more PSCCH DMRS from the last DMRS symbol to the first DMRS symbol of one or more PSCCH DMRS.

[0200] In aspect 48, the method of any one of aspects 38-46 further comprises: the indication indicating that the PSSCH carries a discovery message by mapping one or more PSCCH DMRS from a first DMRS symbol to the last DMRS symbol of one or more PSCCH DMRS, and the indication indicating that the PSSCH does not carry a discovery message by mapping one or more PSCCH DMRS from the last DMRS symbol to the first DMRS symbol of one or more PSCCH DMRS.

[0201] In aspect 49, the method of any one of aspects 38-48 further comprises: the indication based on the PSSCHDMRS mapping or the PSSCH resource mapping indicating that the PSSCH carries a discovery message.

[0202] In aspect 50, the method of any one of aspects 38-49 further comprises: a first mapping of the PSSCH from the lowest PRB to the highest PRB indicating that the PSSCH carries a discovery message, and a second mapping of the PSSCH from the highest PRB to the lowest PRB indicating that the PSSCH does not carry a discovery message.

[0203] In aspect 51, the method of any one of aspects 38-49 further comprises: a first mapping of the PSSCH from the lowest PRB to the highest PRB indicating that the PSSCH does not carry a discovery message, and a second mapping of the PSSCH from the highest PRB to the lowest PRB indicating that the PSSCH carries a discovery message.

[0204] In aspect 52, the method of any one of aspects 38-51 further comprises: if the second part of the SCI is transmitted via a plurality of PSSCH symbols, the indication indicates that the PSSCH does not carry a discovery message by mapping one or more PSSCH DMRS from the first PSSCH symbol carrying the second part of the SCI to the last PSSCH symbol carrying the second part of the SCI, and the indication indicates that the PSSCH carries the discovery message by mapping one or more PSSCH DMRS from the last PSSCH symbol carrying the second part of the SCI to the first PSSCH symbol carrying the second part of the SCI.

[0205] In aspect 53, the method of any one of aspects 38-51 further comprises: if the second part of the SCI is transmitted via a plurality of PSSCH symbols, the indication indicates that the PSSCH carries a discovery message by mapping one or more PSCCH DMRS from the first PSCCH symbol carrying the second part of the SCI to the last PSCCH symbol carrying the second part of the SCI, and the indication indicates that the PSSCH does not carry a discovery message by mapping one or more PSCCH DMRS from the last PSSCH symbol carrying the second part of the SCI to the first PSSCH symbol carrying the second part of the SCI.

[0206] In aspect 54, the method of any one of aspects 38-53 further comprises: a first wireless device monitoring the indication in a discovery indication signal, the indication indicating whether a PSSCH or subsequent PSCCH carries a discovery message.

[0207] In aspect 55, the method of any one of aspects 38-54 further includes: detecting that the indicator signal comprises a sequence.

[0208] In aspect 56, the method of any one of aspects 38-55 further comprises: a first wireless device monitoring a discovery indication signal in the same time slot as the PSSCH and PSCCH.

[0209] In aspect 57, the method of any one of aspects 38-55 further comprises: a first wireless device monitoring a discovery indication signal on a physical channel different from the PSCCH and PSSCH.

[0210] In aspect 58, the method of any one of aspects 38-57 further comprises: finding that the indication signal shares one or more DMRS with the PSSCH, or finding that the indication signal includes one or more DMRS.

[0211] In aspect 59, the method of any one of aspects 38-58 further comprises: the discovery indication signal sharing the same sidelink resource pool as the discovery message and the communication message, and the discovery indication signal not using resources that conflict with one or more DMRSs of the PSSCH or PSCCH.

[0212] In aspect 60, the method of any one of aspects 38-59 further comprises: a discovery indication signal being associated with a PSCCH or PSSCH carrying a discovery message, and the presence of the discovery indication signal indicating that a discovery message will be sent in the PSCCH or PSSCH.

[0213] In aspect 61, the method of any one of aspects 38-60 further includes: the discovery indication signal including information indicating that a discovery message will be sent or that a discovery message will not be sent.

[0214] In aspect 62, the method of any one of aspects 38-61 further comprises: the discovery indication signal comprising one or more reference signals for performing at least one of time tracking, frequency tracking or Doppler estimation for PSCCH or PSSCH decoding.

[0215] In aspect 63, the method of any one of aspects 38-62 further comprises: the detection indication signal including one or more reference signals for performing mobility management or radio link monitoring.

[0216] In aspect 64, the method of any one of aspects 38-63 further comprises: a first wireless device monitoring the indication in the PSFCH.

[0217] In aspect 65, the method of any one of aspects 38-64 further includes: the indication indicating an associated subchannel for receiving a discovery message.

[0218] In aspect 66, the method of any one of aspects 38-65 further comprises: the indication within the PSFCH having an independent configuration relative to the configuration for reporting side link feedback within the PSFCH.

[0219] In aspect 67, the method of any one of aspects 38-66 further comprises: the independent configuration configuring at least one of the indicated period, number of symbols, or number of PRBs.

[0220] In aspect 68, the method of any one of aspects 38-67 further includes: the indication comprising a plurality of bits.

[0221] In aspect 69, the method of any one of aspects 38-68 further includes: the indication indicating the type of the discovery message.

[0222] In aspect 70, the method of any one of aspects 38-69 further includes: the type of discovery message includes an announcement message or a solicitation message.

[0223] Aspect 71 is an apparatus for wireless communication, comprising: a unit for monitoring an indication from a second wireless device indicating whether a PSSCH carries a discovery message; a unit for determining whether a PSSCH carries a discovery message; and a unit for monitoring a discovery message in a PSSCH if a first wireless device receives the indication and the indication indicates that the PSSCH carries a discovery message.

[0224] In aspect 72, the apparatus of aspect 71 further includes a unit for performing the method described in any one of aspects 39-70.

[0225] Aspect 73 is an apparatus for wireless communication, comprising: a memory; and at least one processor coupled to the memory, the memory and the at least one processor being configured to perform the method of claims 38-70.

[0226] Aspect 74 is a non-transitory computer-readable storage medium storing computer-executable code for wireless communication at a first wireless device, which, when executed by a processor, causes the processor to perform the method described in any one of claims 38-70.

[0227] Aspect 75 is a method of wireless communication at a first wireless device, comprising: sending an indication to a second wireless device, the indication indicating in physical layer signaling whether a PSSCH carries a discovery message; and sending a PSSCH at least in part based on the indication.

[0228] In aspect 76, the method of aspect 75 further includes: the indication instructs the PSSCH to carry a discovery message, the method further including: sending the discovery message in the PSSCH.

[0229] In aspect 77, the method of aspect 75 further includes: the indication indicating that the PSSCH does not carry a discovery message, the method further including: sending a communication message in the PSSCH in the absence of a discovery message.

[0230] In aspect 78, the method of any one of aspects 75-77 further comprises: sending the instruction in at least one of the first part of the SCI in the PSCCH or the second part of the SCI in the PSSCH.

[0231] In aspect 79, the method of any one of aspects 75-78 further comprises: the first wireless device transmitting the indication in one or more reserved bits in the first part of the SCI.

[0232] In aspect 80, the method of any one of aspects 75-78 further comprises: the first wireless device transmitting the instruction in a second part of the SCI.

[0233] In aspect 81, the method of any one of aspects 75-80 further comprises: the indication indicating whether the PSSCH carries a discovery message based on the PSCCHDMRS mapping or the PSCCH resource mapping.

[0234] In aspect 82, the method of any one of aspects 75-81 further comprises: the indication indicating whether the PSSCH carries a discovery message based on the PSSCHDMRS mapping or the PSSCH resource mapping.

[0235] In aspect 83, the method of any one of aspects 75-82 further comprises: a first wireless device transmitting the indication in a physical-side cross-link discovery indication channel, the indication indicating whether the PSSCH or PSCCH carries a discovery message.

[0236] In aspect 84, the method of any one of aspects 75-83 further includes: the indication further includes one or more of a source ID or a destination ID.

[0237] In aspect 85, the method of any one of aspects 75-84 further includes: transmitting a physical-side link discovery indication channel, which further includes transmitting the physical-side link discovery indication channel in the same time slot as the PSSCH and PSCCH.

[0238] In aspect 86, the method of any one of aspects 75-84 further comprises: a first wireless device transmitting the indication in a physical side crosslink discovery indication channel in a time slot having the same structure as a time slot including a physical side crosslink feedback channel (PSFCH).

[0239] In aspect 87, the method of any one of aspects 75-86 further comprises: the physical-side crosslink discovery indication channel sharing one or more DMRSs with the PSSCH, or the physical-side crosslink discovery indication channel including one or more DMRSs.

[0240] In aspect 88, the method of any one of aspects 75-87 further comprises: the physical side walkway discovery indication channel sharing the same side walkway resource pool as the discovery message and the communication message, the method further comprising: using resources for the physical side walkway discovery indication channel that do not conflict with one or more DMRSs of the PSSCH or PSCCH.

[0241] In aspect 89, the method of any one of aspects 75-88 further comprises: a physical-side crosslink discovery indication channel associated with a PSCCH or PSSCH carrying a discovery message, and the presence of the physical-side crosslink discovery indication channel indicates that a discovery message will be sent in the PSCCH or PSSCH.

[0242] In aspect 90, the method of any one of aspects 75-89 further comprises: the physical-side link discovery indication channel including information indicating that a discovery message will be sent or that a discovery message will not be sent.

[0243] In aspect 91, the method of any one of aspects 75-90 further comprises: the physical-side link discovery indication channel including one or more reference signals for performing at least one of time tracking, frequency tracking, Doppler estimation, mobility management, or radio link monitoring for PSCCH or PSSCH.

[0244] In aspect 92, the method of any one of aspects 75-91 further comprises: the first wireless device transmitting the instruction in the PSFCH.

[0245] In aspect 93, the method of any one of aspects 75-92 further includes: sending one or more of the source ID or destination ID in the PSFCH.

[0246] In aspect 94, the method of any one of aspects 75-93 further includes: the indication indicating an associated subchannel for sending a discovery message.

[0247] In aspect 95, the method of any one of aspects 75-94 further comprises: the indication within the PSFCH having an independent configuration relative to the configuration for reporting side-link feedback in the PSFCH.

[0248] In aspect 96, the method of any one of aspects 75-95 further includes: the indication indicating the type of the discovery message.

[0249] Aspect 97 is an apparatus for wireless communication, comprising at least one processor coupled to a memory and configured to implement the method described in any one of aspects 75 to 96.

[0250] Aspect 98 is an apparatus for wireless communication, comprising units for implementing the method described in any one of aspects 75 to 96.

[0251] Aspect 99 is a non-transitory computer-readable storage medium storing computer-executable code, wherein when executed by a processor, the code causes the processor to perform the methods described in any one of aspects 75 to 96.

[0252] Aspect 100 is a method of wireless communication at a first wireless device, comprising: receiving an indication from a second wireless device, the indication indicating in physical layer signaling whether a PSSCH carries a discovery message; determining whether the PSSCH carries a discovery message; and if the indication indicates that the PSSCH carries a discovery message, decoding the discovery message in the PSSCH.

[0253] In aspect 101, the method of aspect 100 further includes: the indication instructs the PSSCH to carry a discovery message, the method further including: decoding the discovery message in the PSSCH in response to receiving the indication.

[0254] In aspect 102, the method of aspect 100 further includes: the indication indicating that the PSSCH does not carry a discovery message, the method further including: skipping the decoding of the PSSCH in response to receiving the indication.

[0255] In aspect 103, the method of any one of aspects 100-102 further comprises: a first wireless device receiving the instruction in at least one of a first portion of the SCI in the PSCCH or a second portion of the SCI in the PSSCH.

[0256] In aspect 104, the method of any one of aspects 100-103 further comprises: a first wireless device receiving the indication in a physical-side cross-link discovery indication channel, the indication indicating whether a PSSCH or a subsequent PSCCH carries a discovery message.

[0257] In aspect 105, the method of any one of aspects 100-104 further comprises: a first wireless device receiving the instruction in the PSFCH.

[0258] Aspect 106 is an apparatus for wireless communication, including at least one processor coupled to a memory and configured to implement the method described in any one of aspects 100 to 105.

[0259] Aspect 107 is an apparatus for wireless communication, comprising units for implementing the method described in any one of aspects 100 to 105.

[0260] Aspect 108 is a non-transitory computer-readable storage medium storing computer-executable code, wherein when executed by a processor, the code causes the processor to perform the methods described in any one of aspects 100 to 105.

[0261] It is understood that the specific order or hierarchy of boxes in the disclosed process / flowchart is illustrative of the example method. Based on design preferences, it is understood that the specific order or hierarchy of boxes in the process / flowchart can be rearranged. Furthermore, some boxes can be combined or omitted. The appended method claims describe the elements of various boxes in a sample order and are not intended to limit the specific order or hierarchy described.

[0262] The above description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be apparent to those skilled in the art, and the general principles defined herein can also be applied to other aspects. Therefore, the claims are not intended to be limited to the aspects shown herein, but rather to be given the full scope consistent with the language of the claims, wherein, unless specifically stated otherwise, reference to a singular element does not mean “one and only one,” but rather “one or more.” Terms such as “if,” “when,” and “at the time of,” should be interpreted as meaning “under the following conditions,” rather than implying an immediate temporal relationship or reaction. That is, these phrases, such as “when,” do not imply a reaction to an action or an immediate action during the occurrence of the action, but simply mean that if the condition is met, then the action will occur, without requiring a specific or immediate time limit for the action to occur. The term “exemplary” as used herein means “as an example, instance, or illustration.” Any aspect described herein as “exemplary” is not necessarily to be construed as more preferred or advantageous than other aspects. Unless specifically stated otherwise, the term “some” means one or more. Combinations such as "at least one of A, B, or C", "one or more of A, B, or C", "at least one of A, B, and C", "one or more of A, B, and C", and "A, B, C, or any combination thereof" include any combination of A, B, and / or C, and may include multiples of A, multiples of B, or multiples of C. Specifically, combinations such as "at least one of A, B, or C", "one or more of A, B, or C", "at least one of A, B, and C", "one or more of A, B, and C", and "A, B, C, or any combination thereof" may be only A, only B, only C, A and B, A and C, B and C, or A and B and C, wherein any such combination may contain one or more members of A, B, or C. All structural and functional equivalents of the elements throughout the aspects described in this disclosure are known or subsequently known to those skilled in the art, are expressly incorporated herein by reference, and are intended to be included in the claims. Furthermore, nothing disclosed herein is intended to be offered to the public, whether or not such disclosure is expressly mentioned in the claims. The terms “module,” “mechanism,” “element,” and “device” are not substitutes for the word “unit.” Therefore, unless a claim element is explicitly stated using the phrase “unit for…”, no claim element is to be interpreted as a unit plus a function.

Claims

1. A method for wireless communication at a first wireless device, comprising: An indication is sent to the second wireless device based on at least one of the following: Physical-side Cross-link Control Channel (PSCCH) Demodulation Reference Signal (DMRS) mapping, PSCCH resource mapping, Physical-side Cross-link Shared Channel (PSSCH) DMRS mapping, or PSSCH resource mapping, wherein the indication indicates in physical layer signaling whether the PSSCH carries a discovery message. as well as The PSSCH is sent at least in part based on the instruction.

2. The method according to claim 1, wherein, The instruction instructs the PSSCH to carry the discovery message, and the method further includes: The discovery message is sent in the PSSCH.

3. The method according to claim 1, wherein, The indication indicates that the PSSCH does not carry the discovery message, and the method further includes: In the absence of the discovery message, a communication message is sent in the PSSCH.

4. The method according to claim 1, wherein, The instruction is based on mapping the first DMRS symbol of the PSCCH to the last DMRS symbol of the PSCCH or mapping the last DMRS symbol of the PSCCH to the PSCCH DMRS mapping of the first DMRS symbol of the PSCCH.

5. The method according to claim 1, wherein, The instruction is based on mapping the first DMRS symbol of the PSSCH to the last DMRS symbol of the PSSCH or mapping the last DMRS symbol of the PSSCH to the PSSCH DMRS mapping of the first DMRS symbol of the PSSCH.

6. The method according to claim 1, wherein, The instruction is based on the PSCCH resource mapping that maps the PSCCH from the lowest physical resource block (PRB) to the highest PRB or the PSCCH from the highest PRB to the lowest PRB.

7. The method according to claim 1, wherein, The instruction is based on the PSSCH resource mapping that maps the PSSCH from the lowest physical resource block (PRB) to the highest PRB or from the highest PRB to the lowest PRB.

8. The method according to claim 1, wherein, The instruction indicates the type of the discovery message.

9. An apparatus for wireless communication of a first wireless device, comprising: A unit for sending an indication to a second wireless device based on at least one of Physical Side Cross-Link Control Channel (PSCCH) Demodulation Reference Signal (DMRS) mapping, PSCCH resource mapping, Physical Side Cross-Link Shared Channel (PSSCH) DMRS mapping, or PSSCH resource mapping, wherein the indication indicates in physical layer signaling whether the PSSCH carries a discovery message. as well as A unit for sending the PSSCH based at least in part on the instruction.

10. The apparatus according to claim 9, wherein, The instruction is based on mapping the first DMRS symbol of the PSSCH to the last DMRS symbol of the PSSCH or mapping the last DMRS symbol of the PSSCH to the PSSCH DMRS mapping of the first DMRS symbol of the PSSCH.

11. The apparatus according to claim 9, further comprising: Units for performing the method according to any one of claims 2-4 and 6-8.

12. A method for wireless communication at a first wireless device, comprising: The indication from the second radio device is received based on at least one of the following: Physical-side Cross-link Control Channel (PSCCH) Demodulation Reference Signal (DMRS) mapping, PSCCH resource mapping, Physical-side Cross-link Shared Channel (PSSCH) DMRS mapping, or PSSCH resource mapping, wherein the indication in physical layer signaling indicates whether the PSSCH carries a discovery message. as well as In response to the indication that the PSSCH carries the discovery message, the discovery message in the PSSCH is decoded.

13. The method according to claim 12, wherein, The instruction instructs the PSSCH to carry the discovery message, and the method further includes: In response to receiving the instruction, the discovery message in the PSSCH is decoded.

14. The method according to claim 12, wherein, The indication does not instruct the PSSCH to carry the discovery message, and the method further includes: In response to receiving the instruction, the decoding of the PSSCH is skipped.

15. The method according to claim 12, wherein, The instruction is based on mapping the first DMRS symbol of the PSSCH to the last DMRS symbol of the PSSCH or mapping the last DMRS symbol of the PSSCH to the PSSCH DMRS mapping of the first DMRS symbol of the PSSCH.

16. The method according to claim 12, wherein, The instruction is based on the PSSCH resource mapping that maps the PSSCH from the lowest physical resource block (PRB) to the highest PRB or from the highest PRB to the lowest PRB.

17. An apparatus for wireless communication at a first wireless device, comprising: A unit for receiving an indication from a second wireless device based on at least one of Physical Side Cross-Link Control Channel (PSCCH) Demodulation Reference Signal (DMRS) mapping, PSCCH resource mapping, Physical Side Cross-Link Shared Channel (PSSCH) DMRS mapping, or PSSCH resource mapping, wherein the indication indicates in physical layer signaling whether the PSSCH carries a discovery message. as well as A unit for decoding the discovery message in the PSSCH in response to the indication that the PSSCH carries the discovery message.

18. The apparatus according to claim 17, wherein, The instruction is based on mapping the first DMRS symbol of the PSSCH to the last DMRS symbol of the PSSCH or mapping the last DMRS symbol of the PSSCH to the PSSCH DMRS mapping of the first DMRS symbol of the PSSCH.

19. The apparatus of claim 17, further comprising: Units for performing the method according to any one of claims 13-14 and 16.

20. An apparatus for wireless communication at a first wireless device, comprising: One or more memory units; as well as One or more processors, coupled to the one or more memories, and configured to cause the first wireless device to perform the following operations: An indication is sent to the second wireless device based on at least one of the following: Physical-side Cross-link Control Channel (PSCCH) Demodulation Reference Signal (DMRS) mapping, PSCCH resource mapping, Physical-side Cross-link Shared Channel (PSSCH) DMRS mapping, or PSSCH resource mapping, wherein the indication indicates in physical layer signaling whether the PSSCH carries a discovery message. as well as The PSSCH is sent at least in part based on the instruction.

21. The apparatus according to claim 20, wherein, The instruction is based on mapping the first DMRS symbol of the PSCCH to the last DMRS symbol of the PSCCH or mapping the last DMRS symbol of the PSCCH to the PSCCH DMRS mapping of the first DMRS symbol of the PSCCH.

22. The apparatus according to claim 20, wherein, The instruction is based on mapping the first DMRS symbol of the PSSCH to the last DMRS symbol of the PSSCH or mapping the last DMRS symbol of the PSSCH to the PSSCH DMRS mapping of the first DMRS symbol of the PSSCH.

23. The apparatus according to claim 20, wherein, The instruction is based on the PSCCH resource mapping that maps the PSCCH from the lowest physical resource block (PRB) to the highest PRB or the PSCCH from the highest PRB to the lowest PRB.

24. The apparatus according to claim 20, wherein, The one or more processors are configured to individually or in combination cause the first wireless device to send the instruction and to send the PSSCH.

25. The apparatus according to claim 20, wherein, The one or more processors are further configured to cause the first wireless device to perform the method according to any one of claims 2, 3, 7, and 8.

26. A non-transitory computer-readable storage medium storing computer-executable code at a first wireless device, the code causing the at least one processor, when executed, to: An indication is sent to the second wireless device based on at least one of the following: Physical-side Cross-link Control Channel (PSCCH) Demodulation Reference Signal (DMRS) mapping, PSCCH resource mapping, Physical-side Cross-link Shared Channel (PSSCH) DMRS mapping, or PSSCH resource mapping, wherein the indication indicates in physical layer signaling whether the PSSCH carries a discovery message; and The PSSCH is sent at least in part based on the instruction.

27. The non-transitory computer-readable storage medium according to claim 26, wherein, The instruction is based on mapping the first DMRS symbol of the PSSCH to the last DMRS symbol of the PSSCH or mapping the last DMRS symbol of the PSSCH to the PSSCH DMRS mapping of the first DMRS symbol of the PSSCH.

28. The non-transitory computer-readable storage medium according to claim 26, wherein, When the code is executed by at least one processor, it also causes the at least one processor to perform the method according to any one of claims 2-4 and 6-8.

29. An apparatus for wireless communication at a first wireless device, comprising: One or more memory units; as well as One or more processors, coupled to the one or more memories, and configured to cause the first wireless device to perform the following operations: The indication from the second radio device is received based on at least one of the following: Physical-side Cross-link Control Channel (PSCCH) Demodulation Reference Signal (DMRS) mapping, PSCCH resource mapping, Physical-side Cross-link Shared Channel (PSSCH) DMRS mapping, or PSSCH resource mapping, wherein the indication in physical layer signaling indicates whether the PSSCH carries a discovery message. as well as In response to the indication that the PSSCH carries the discovery message, the discovery message in the PSSCH is decoded.

30. The apparatus according to claim 29, wherein, The instruction is based on mapping the first DMRS symbol of the PSSCH to the last DMRS symbol of the PSSCH or mapping the last DMRS symbol of the PSSCH to the PSSCH DMRS mapping of the first DMRS symbol of the PSSCH.

31. The apparatus according to claim 29, wherein, The one or more processors are configured to individually or in combination cause the first wireless device to receive the indication and decode the discovery message in the PSSCH.

32. The apparatus according to claim 29, wherein, The one or more processors are further configured to cause the first wireless device to perform the method according to claim 14 or 16.

33. A non-transitory computer-readable storage medium storing computer-executable code at a first wireless device, the code causing the at least one processor, when executed, to: The indication from the second wireless device is received based on at least one of the following: Physical-side Cross-link Control Channel (PSCCH) Demodulation Reference Signal (DMRS) mapping, PSCCH resource mapping, Physical-side Cross-link Shared Channel (PSSCH) DMRS mapping, or PSSCH resource mapping, wherein the indication indicates in physical layer signaling whether the PSSCH carries a discovery message; and In response to the indication that the PSSCH carries the discovery message, the discovery message in the PSSCH is decoded.

34. The non-transitory computer-readable storage medium according to claim 33, wherein, The instruction is based on the PSSCH resource mapping that maps the PSSCH from the lowest physical resource block (PRB) to the highest PRB or from the highest PRB to the lowest PRB.

35. The non-transitory computer-readable storage medium according to claim 33, wherein, When the code is executed by at least one processor, it also causes the at least one processor to perform the method according to any one of claims 13-15.

Images