Method and apparatus for sidelink initial beam acquisition

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. Methods and apparatus for sidelink (SL) initial beam acquisition in a wireless communication system. A method for operating a user equipment (UE) includes transmitting a first physical sidelink control channel (PSCCH) and a corresponding first physical sidelink shared channel (PSSCH) to a second UE using a plurality of spatial domain transmission filters, respectively. The first PSCCH and the corresponding first PSSCH include a first link setup message. The method also includes receiving assistance information associated with the spatial domain transmission filter from the second UE. The method further includes determining a spatial domain transmission filter based on the auxiliary information. The method further includes transmitting a second PSCCH and a corresponding second PSSCH to a second UE based on the spatial domain transmission filter.

Description

Technical Field

[0001] The present disclosure relates generally to wireless communication systems, and more particularly, to methods and apparatus for sidelink (SL) initial beam acquisition. Background Art

[0002] 5G mobile communication technology defines a wide frequency band so that high transmission rates and new services are possible, and can be realized not only in "below 6 GHz" frequency bands such as 3.5 GHz, but also in "above 6 GHz" frequency bands called millimeter waves including 28 GHz and 39 GHz. In addition, it has been considered to implement 6G mobile communication technology (called super 5G system) in terahertz (THz) frequency bands (e.g., 95 GHz to 3 THz frequency bands) in order to achieve a transmission rate fifty times faster than 5G mobile communication technology and an ultra-low latency one-tenth of 5G mobile communication technology.

[0003] At the beginning of the development of 5G mobile communication technology, in order to support services and meet performance requirements related to enhanced mobile broadband (eMBB), ultra-reliable low latency communication (URLLC), and massive machine type communication (mMTC), there has been ongoing standardization on the following aspects: beamforming and massive MIMO for mitigating radio wave path loss in millimeter waves and increasing radio wave transmission distance, dynamic operation of parameter sets (e.g., operating multiple subcarrier spacings) and time slot formats to support efficient utilization of millimeter wave resources, initial access technology for supporting multi-beam transmission and broadband, definition and operation of BWP (bandwidth part), new channel coding methods such as LDPC (low-density parity check) codes for large-scale data transmission and polar codes for highly reliable transmission of control information, L2 preprocessing, and network slicing for providing dedicated networks customized for specific services.

[0004] Currently, there are ongoing discussions on improvements and performance enhancements to initial 5G mobile communication technologies in view of the services they are to support, and there is already physical layer standardization on technologies such as: V2X (Vehicle to Everything) for assisting driving decisions of autonomous vehicles based on information about the location and status of a vehicle sent by the vehicle and for enhancing user convenience, NR-U (Unlicensed New Radio) for system operation designed to comply with various regulatory-related requirements within unlicensed bands, NR UE energy saving, non-terrestrial networks (NTNs) as UE-satellite direct communication for providing coverage in areas where communication with terrestrial networks is not possible, and positioning.

[0005] In addition, in the air interface architecture / protocol, there is already ongoing standardization on technologies such as the Industrial Internet of Things (IIoT) that supports new services through interconnection and convergence with other industries, IAB (Integrated Access and Backhaul) that provides nodes for network service area expansion by supporting wireless backhaul links and access links in an integrated manner, mobility enhancements including conditional handover and DAPS (Dual Active Protocol Stack) handover, and two-step random access (two-step RACH for NR) for simplifying the random access process. Standardization is also ongoing in terms of system architecture / services: a 5G baseline architecture (e.g., a service-based architecture or a service-based interface) for combining network function virtualization (NFV) and software defined network (SDN) technologies, and mobile edge computing (MEC) for receiving services based on UE location.

[0006] As 5G mobile communication systems are commercialized, the number of connected devices, which has been growing exponentially, will be connected to the communication network, and it is expected that enhanced functions and performance of the 5G mobile communication systems and integrated operations of the connected devices will be necessary. To this end, new research is arranged on extended reality (XR) for effectively supporting AR (augmented reality), VR (virtual reality), MR (mixed reality), etc., 5G performance improvement and complexity reduction by utilizing artificial intelligence (AI) and machine learning (ML), AI service support, metaverse service support, and drone communication.

[0007] In addition, such development of 5G mobile communication systems will serve as the basis for not only developing new waveforms for providing terahertz band coverage for 6G mobile communication technology, multi-antenna transmission technologies such as full-dimensional MIMO (FD-MIMO), array antennas, and massive antennas, metamaterial-based lenses and antennas for improving terahertz band signal coverage, high-dimensional spatial multiplexing technology using OAM (orbital angular momentum), and RIS (reconfigurable smart surface), but also developing full-duplex technology for improving the frequency efficiency of 6G mobile communication technology and improving system networks, AI-based communication technology for achieving system optimization and internalizing end-to-end AI support functions by utilizing satellites and AI (artificial intelligence) from the design stage, and next-generation distributed computing technology for implementing services at a complexity level that exceeds the limits of UE operating capabilities by utilizing ultra-high performance communication and computing resources. Summary of the invention

[0008] Solution to the problem

[0009] The present disclosure relates to a wireless communication network, and more particularly to a terminal and a communication method thereof in a wireless communication system.

[0010] According to one aspect of the present disclosure, a user equipment (UE) is provided. The UE includes a transceiver configured to send a first physical side link (SL) control channel (PSCCH) and a corresponding first physical SL shared channel (PSSCH) to a second UE using multiple spatial domain transmission filters, respectively. The first PSCCH and the corresponding first PSSCH include a first link establishment message. The transceiver is also configured to receive auxiliary information associated with the spatial domain transmission filter from the second UE. The UE also includes a processor operably coupled to the transceiver. The processor is configured to determine the spatial domain transmission filter based on the auxiliary information. The transceiver is also configured to send a second PSCCH and a corresponding second PSSCH to the second UE based on the spatial domain transmission filter.

[0011] Beneficial Effects

[0012] Aspects of the present disclosure are to address at least the above problems and / or disadvantages and to provide at least the advantages described below. Therefore, one aspect of the present disclosure is to provide an efficient communication method in a wireless communication system. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The above and other aspects, features and advantages of certain embodiments of the present disclosure will become more apparent through the following description in conjunction with the accompanying drawings, in which:

[0014] Figure 1 An example wireless network according to an embodiment of the present disclosure is shown;

[0015] Figure 2 An example gNodeB (gNB) according to an embodiment of the present disclosure is shown;

[0016] Figure 3 An example UE according to an embodiment of the present disclosure is shown;

[0017] Figure 4A An example of a wireless transmission path according to an embodiment of the present disclosure is shown;

[0018] Figure 4B An example of a wireless receive path according to an embodiment of the present disclosure is shown;

[0019] Figure 5A An example of a wireless system according to an embodiment of the present disclosure is shown;

[0020] Figure 5B An example of multi-beam operation according to an embodiment of the present disclosure is shown;

[0021] Figure 6 An example of a transmitter structure for beamforming according to an embodiment of the present disclosure is shown;

[0022] Figure 7A flowchart illustrating an example process for Layer 2 link establishment for unicast mode of vehicle-to-everything (V2X) communication over a protocol layer convergence (PC5) reference point of 5G New Radio according to an embodiment of the present disclosure;

[0023] Figure 8 An example of transceiver configuration indication (TCI) signaling according to an embodiment of the present disclosure is shown;

[0024] Fig. 9 An example of initial beam acquisition according to an embodiment of the present disclosure is shown;

[0025] Fig.10 An example of an implementation of a slot index for linking to a transmission beam according to an embodiment of the present disclosure is shown;

[0026] Fig.11 Another example of an implementation for linking a slot index to a transmission beam according to an embodiment of the present disclosure is shown;

[0027] Fig.12 Another example of an implementation for linking a slot index to a transmission beam according to an embodiment of the present disclosure is shown;

[0028] Fig.13 An example of an SL synchronization signal block (S-SSB) according to an embodiment of the present disclosure is shown;

[0029] Fig.14 shows examples of transmit and receive beam scanning according to an embodiment of the present disclosure;

[0030] Fig.15 An example of initial beam acquisition according to an embodiment of the present disclosure is shown;

[0031] Fig.16 Another example of S-SSB according to an embodiment of the present disclosure is shown;

[0032] Fig.17 shows examples of transmit and receive beam scanning according to an embodiment of the present disclosure;

[0033] Fig.18 An example method performed by a UE in a wireless communication system according to an embodiment of the present disclosure is shown;

[0034] Fig.19 illustrates various hardware components of a base station according to the disclosed embodiments; and

[0035] Fig. 20 Various hardware components of a UE according to the disclosed embodiments are shown.

[0036] Throughout the drawings, it should be noted that like reference numbers are used to depict the same or similar elements, features, and structures. DETAILED DESCRIPTION

[0037] Aspects of the present disclosure are to address at least the above-mentioned problems and / or disadvantages and to provide at least the advantages described below. Therefore, one aspect of the present disclosure is to provide a terminal in a wireless communication system and a communication method thereof.

[0038] In one embodiment, a user equipment (UE) is provided. The UE includes a transceiver, which is configured to send a first physical side link (SL) control channel (PSCCH) and a corresponding first physical SL shared channel (PSSCH) to a second UE using multiple spatial domain transmission filters, respectively. The first PSCCH and the corresponding first PSSCH include a first link establishment message. The transceiver is also configured to receive auxiliary information associated with the spatial domain transmission filter from the second UE. The UE also includes a processor operably coupled to the transceiver. The processor is configured to determine the spatial domain transmission filter based on the auxiliary information. The transceiver is also configured to send a second PSCCH and a corresponding second PSSCH to the second UE based on the spatial domain transmission filter.

[0039] In another embodiment, a method for operating a UE is provided. The method includes sending a first PSCCH and a corresponding first PSSCH to a second UE using a plurality of spatial domain transmission filters, respectively. The first PSCCH and the corresponding first PSSCH include a first link establishment message. The method also includes receiving auxiliary information associated with the spatial domain transmission filter from the second UE. The method also includes determining the spatial domain transmission filter based on the auxiliary information. The method also includes sending a second PSCCH and a corresponding second PSSCH to the second UE based on the spatial domain transmission filter.

[0040] Other technical features may be apparent to those skilled in the art from the following drawings, descriptions and claims.

[0041] Before the following detailed description, it may be advantageous to set forth the definitions of certain words and phrases used throughout this patent document.The term "coupling" and its derivatives refer to any direct or indirect communication between two or more elements, whether or not these elements are in physical contact with each other.The terms "send", "receive" and "communication" and their derivatives cover both direct and indirect communication.The terms "include" and "comprise" and their derivatives mean including but not limited to.The term "or" is inclusive, meaning and / or.The phrase "associated with ... " and its derivatives mean including, included in ..., interconnected with ..., including, included in ..., connected to or connected with ..., coupled to or coupled with ..., can communicate with ..., collaborate with ..., interlace, juxtapose, approach, bind to or bind with ..., have, have the property of ..., have to ... relationship or have a relationship with ... etc.The term "controller" means any device, system or part thereof that controls at least one operation.Such a controller can be implemented with hardware or a combination of hardware and software and / or firmware.The function associated with any particular controller can be centralized or distributed, whether local or remote. When used with a list of items, the phrase "at least one of" means that different combinations of one or more of the listed items can be used, and only one of the items in the list may be required. For example, "at least one of A, B, and C" includes any of the following combinations: A, B, C, A and B, A and C, B and C, and A and B and C.

[0042] In addition, the various functions described below can be implemented or supported by one or more computer programs, each of which is formed by a computer-readable program code and embodied in a computer-readable medium. The terms "application" and "program" refer to one or more computer programs, software components, instruction sets, processes, functions, objects, classes, instances, related data or a portion thereof suitable for implementation in a suitable computer-readable program code. The phrase "computer-readable program code" includes any type of computer code, including source code, object code and executable code. The phrase "computer-readable medium" includes any type of medium that can be accessed by a computer, such as a read-only memory (ROM), a random access memory (RAM), a hard drive, a compact disk (CD), a digital video disk (DVD) or any other type of memory. "Non-transitory" computer-readable media excludes wired, wireless, optical or other communication links that transmit temporary electrical signals or other signals. Non-transitory computer-readable media include media in which data can be permanently stored and media in which data can be stored and rewritten later, such as rewritable optical disks or erasable memory devices.

[0043] Definitions for certain other words and phrases are provided throughout this patent document. Those of ordinary skill in the art should understand that in many, if not most instances, such definitions apply to prior, as well as future uses of such defined words and phrases.

[0044] Mode for use in the present invention

[0045] The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of the various embodiments of the present disclosure as defined by the claims and their equivalents. It includes various specific details to assist in understanding, but these details are considered to be exemplary only. Therefore, it will be appreciated by those of ordinary skill in the art that various changes and modifications may be made to the various embodiments described herein without departing from the scope and spirit of the present disclosure. In addition, for the sake of clarity and conciseness, descriptions of well-known functions and structures may be omitted.

[0046] The terms and words used in the following description and claims are not limited to their bibliographical meanings, but are merely used by the inventor to enable a clear and consistent understanding of the present disclosure. Therefore, it will be apparent to those skilled in the art that the following description of various embodiments of the present disclosure is provided for illustrative purposes only and not for the purpose of limiting the present disclosure as defined by the appended claims and their equivalents.

[0047] It should be understood that the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a component surface" includes reference to one or more of such surfaces.

[0048] Before carrying out the following detailed description, it may be advantageous to set forth the definitions of certain words and phrases used throughout this patent document.The term "coupling" and its derivatives refer to any direct or indirect communication between two or more elements, whether or not these elements are in physical contact with each other.The terms "send", "receive" and "communication" and their derivatives cover both direct and indirect communication.The terms "include" and "comprise" and their derivatives mean including but not limited to.The term "or" is inclusive, meaning and / or.The phrase "associated with ... " and its derivatives mean including, included in ..., connected to ..., interconnected with ..., including, included in ..., connected to or with ..., coupled to or with ... coupling, can communicate with ..., collaborate with ..., interlace, juxtapose, approach, be bound to or with ... binding, have, have the property of ..., have to ... relationship or with ... have relationship etc.The term "controller" means any device, system or part thereof that controls at least one operation.Such a controller can be implemented with hardware or a combination of hardware and software and / or firmware. The functionality associated with any particular controller may be centralized or distributed, whether local or remote. When used with a list of items, the phrase "at least one of" means that different combinations of one or more of the listed items may be used, and only one of the items in the list may be required. For example, "at least one of A, B, and C" includes any of the following combinations: A, B, C, A and B, A and C, B and C, and A and B and C. For example, "at least one of A, B, and C" includes any of the following combinations: A, B, C, A and B, A and C, B and C, and A, B and C.

[0049] In addition, the various functions described below can be implemented or supported by one or more computer programs, each of which is formed by a computer-readable program code and embodied in a computer-readable medium. The terms "application" and "program" refer to one or more computer programs, software components, instruction sets, processes, functions, objects, classes, instances, related data or a portion thereof suitable for implementation in a suitable computer-readable program code. The phrase "computer-readable program code" includes any type of computer code, including source code, object code and executable code. The phrase "computer-readable medium" includes any type of medium that can be accessed by a computer, such as a read-only memory (ROM), a random access memory (RAM), a hard drive, a compact disk (CD), a digital video disk (DVD) or any other type of memory. "Non-transitory" computer-readable media excludes wired, wireless, optical or other communication links that transmit temporary electrical signals or other signals. Non-transitory computer-readable media include media in which data can be permanently stored and media in which data can be stored and rewritten later, such as rewritable optical disks or erasable memory devices.

[0050] The terms used herein to describe the embodiments of the present disclosure are not intended to limit and / or define the scope of the present disclosure. For example, unless otherwise defined, the technical terms or scientific terms used in the present disclosure should have the common meanings understood by ordinary technicians in the field to which the present disclosure belongs.

[0051] It should be understood that the terms “first”, “second” and the like used in the present disclosure do not indicate any order, quantity or importance, but are merely used to distinguish different components.

[0052] As used herein, any reference to "one example" or "example", "one implementation" or "implementation", "one embodiment" or "embodiment" means that a particular element, feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. The appearances of the phrases "in one embodiment" or "in an example" in different places in the specification are not necessarily referring to the same embodiment.

[0053] As used herein, "a portion" of something means "at least some" of that thing, and thus may mean less than all or all of that thing. Thus, "a portion" of a thing includes the entire thing as a special case, i.e., the entire thing is an example of a portion of a thing.

[0054] As used herein, the term "set" means one or more. Thus, a set of items may be a single item or a set of two or more items.

[0055] In the present disclosure, in order to determine whether a specific condition is satisfied or met, expressions such as "greater than" or "less than" are used as examples, and expressions such as "greater than or equal to" or "less than or equal to" are also applicable and are not excluded. For example, a condition defined with "greater than or equal to" can be replaced with "greater than" (or vice versa), a condition defined with "less than or equal to" can be replaced with "less than" (or vice versa), and the like.

[0056] It will be further understood that similar words such as the terms "comprise" or "include" mean that the elements or objects appearing before the word encompass the listed elements or objects and their equivalents appearing after the word, but do not exclude other elements or objects. Similar words such as "connect" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left" and "right" are only used to indicate relative positional relationships, and when the absolute position of the described object changes, the relative positional relationship may change accordingly.

[0057] Those skilled in the art will appreciate that the principles of the present disclosure can be implemented in any appropriately arranged wireless communication system. For example, although the following detailed description of the embodiments of the present disclosure will be directed to LTE and / or 5G communication systems, those skilled in the art will appreciate that, without departing from the scope of the present disclosure, the gist of the present disclosure can also be applied to other communication systems with similar technical backgrounds and channel formats with slight modifications. The technical solutions of the embodiments of the present application can be applied to various communication systems, and for example, the communication system may include a global system for mobile communications (GSM), a code division multiple access (CDMA) system, a wideband code division multiple access (WCDMA) system, a general packet radio service (GPRS) system, a long term evolution (LTE) system, a LTE frequency division duplex (FDD) system, a LTE time division duplex (TDD) system, a universal mobile communication system (UMTS), a global interconnection for microwave access (WiMAX) communication system, a fifth generation (5G) system or a new radio (NR) system, etc. In addition, the technical solutions of the embodiments of the present application can be applied to future-oriented communication technologies. In addition, the technical solutions of the embodiments of the present application can be applied to future-oriented communication technologies.

[0058] In order to meet the growing demand for wireless data communication services since the deployment of 4G communication systems, efforts have been made to develop improved 5G or quasi-5G communication systems. Therefore, 5G or quasi-5G communication systems are also called "super 4G networks" or "post-LTE systems."

[0059] Discussed below Figure 1-Figure 20 The various non-limiting embodiments used to describe the principles of the present disclosure in this patent document are illustrative only and should not be interpreted in any way as limiting the scope of the present disclosure. Those skilled in the art will appreciate that the principles of the present disclosure can be implemented in any appropriately arranged system or device.

[0060] In order to meet the demand for wireless data services that has increased since the deployment of 4G communication systems, and to realize various vertical applications, 5G / NR communication systems have been developed and are currently being deployed. 5G / NR communication systems are implemented in higher frequency (mmWave) bands (e.g., 28 GHz or 60 GHz bands) to achieve higher data rates, or in lower frequency bands (e.g., 6 GHz) to achieve robust coverage and mobility support. In order to reduce the propagation loss of radio waves and increase the transmission distance, beamforming, massive multiple-input multiple-output (MIMO), full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and massive antenna technology are discussed in 5G / NR communication systems.

[0061] In addition, in the 5G / NR communication system, system network improvements are being developed based on advanced small cells, cloud radio access networks (RAN), ultra-dense networks, device-to-device (D2D) communication, wireless backhaul, mobile networks, collaborative communications, coordinated multi-point (CoMP), receiving-end interference cancellation, radio access technology (RAT)-related positioning, etc.

[0062] The discussion of 5G systems and frequency bands associated therewith is for reference, as certain embodiments of the present disclosure may be implemented in 5G systems. However, the present disclosure is not limited to 5G systems or frequency bands associated therewith, and embodiments of the present disclosure may be used in conjunction with any frequency band. For example, aspects of the present disclosure may also be applied to the deployment of 5G communication systems, 6G, or even later versions that may use terahertz (THz) frequency bands.

[0063] The following documents and standard descriptions are incorporated by reference into the present disclosure as if fully set forth herein: [1] 3GPP TS 38.211 v17.5.0, “NR; Physical channels and modulation;” [2] 3GPP TS 38.212 v17.5.0, “NR; Multiplexing and Channel coding;” [3] 3GPP TS 38.213 v17.6.0, “NR; Physical Layer Procedures for Control;” [4] 3GPP TS 38.214 v17.6.0, “NR; Physical Layer Procedures for Data;” [5] 3GPP TS 38.321 v17.5.0, “NR; Medium Access Control (MAC) protocol specification;” [6] 3GPP TS 38.331 v17.5.0, “NR; NR; Radio Resource Control (RRC) Protocol Specification”; [7] 3GPP TS 36.213 v17.5.0, “Evolved Universal Terrestrial Radio Access (E-UTRA); Physical layer procedures”; and [8] RP-213678, “WID on NR sidelink evolution”.

[0064] The following Figure 1-Figure 3 Various embodiments are described that may be implemented using Orthogonal Frequency Division Multiplexing (OFDM) or Orthogonal Frequency Division Multiple Access (OFDMA) communication techniques in a wireless communication system. Figure 1-Figure 3 The description is not meant to imply physical or architectural limitations to how different embodiments may be implemented. Different embodiments of the disclosure may be implemented in any suitably arranged communications system.

[0065] Figure 1 An example wireless network 100 is shown in accordance with an embodiment of the present disclosure. Figure 1The embodiment of the wireless network 100 shown is for illustration only. Other embodiments of the wireless network 100 may be used without departing from the scope of the present disclosure.

[0066] like Figure 1 As shown, wireless network 100 includes gNB 101 (e.g., base station, BS), gNB 102, and gNB 103. gNB 101 communicates with gNB 102 and gNB 103. gNB 101 also communicates with at least one network 130 (such as the Internet, a proprietary Internet Protocol (IP) network, or other data network).

[0067] gNB 102 provides wireless broadband access to network 130 for a first plurality of user equipment (UE) within coverage area 120 of gNB 102. The first plurality of UEs include: UE 111, which may be located in a small business; UE 112, which may be located in an enterprise; UE 113, which may be a WiFi hotspot; UE 114, which may be located in a first residence; UE 115, which may be located in a second residence; and UE 116, which may be a mobile device such as a cellular phone, a wireless laptop, a wireless PDA, etc. gNB 103 provides wireless broadband access to network 130 for a second plurality of UEs within coverage area 125 of gNB 103. The second plurality of UEs includes UE 115 and UE 116. In some embodiments, one or more of gNBs 101-103 may communicate with each other and with UEs 111-116 using 5G / NR, Long Term Evolution (LTE), Long Term Evolution-Advanced (LTE-A), WiMAX, WiFi, or other wireless communication technologies.

[0068] In another example, UE 116 may be within network coverage and another UE may be outside network coverage (e.g., UEs 111A-111C). In yet another example, both UEs are outside network coverage. In some embodiments, one or more of gNBs 101-103 may communicate with each other and with UEs 111-116 using 5G / NR, LTE, LTE-A, WiMAX, WiFi, or other wireless communication technologies. In some embodiments, UEs 111-116 may communicate using a device-to-device (D2D) interface referred to as PC5 (e.g., also referred to as a sidelink at the physical layer).

[0069] Depending on the network type, the term "base station" or "BS" may refer to any component (or collection of components) configured to provide wireless access to a network, such as a transmission point (TP), a transmission-reception point (TRP), an enhanced base station (eNodeB or eNB), a 5G / NR base station (gNB), a macro cell, a femto cell, a WiFi access point (AP), or other wireless enabling devices. The base station may provide wireless access according to one or more wireless communication protocols (e.g., 5G / NR Third Generation Partnership Project (3GPP) NR, Long Term Evolution (LTE), LTE Advanced (LTE-A), High Speed ​​Packet Access (HSPA), Wi-Fi 802.11a / b / g / n / ac, etc.). For convenience, the terms "BS" and "TRP" are used interchangeably in this patent document to refer to network infrastructure components that provide wireless access to remote terminals. In addition, depending on the network type, the term "user equipment" or "UE" may refer to any component, such as a "mobile station", "subscriber station", "remote terminal", "wireless terminal", "reception point", or "user equipment". For convenience, the terms "user equipment" and "UE" are used in this patent document to refer to a remote wireless device that wirelessly accesses a BS, whether the UE is a mobile device (such as a mobile phone or smartphone) or is generally considered a fixed device (such as a desktop computer or vending machine).

[0070] The dashed lines illustrate the approximate extents of coverage areas 120 and 125, which are shown as approximately circular for purposes of illustration and explanation only. It should be clearly understood that coverage areas associated with a gNB, such as coverage areas 120 and 125, may have other shapes, including irregular shapes, depending on the configuration of the gNB and variations in the radio environment associated with natural and man-made obstacles.

[0071] As described in more detail below, one or more of the UEs 111-116 include circuits, procedures, or a combination thereof for utilizing SL initial beam acquisition. In certain embodiments, one or more of the UEs 111-116 also include circuits, procedures, or a combination thereof to support SL initial beam acquisition.

[0072] although Figure 1 An example of a wireless network is shown, but Figure 1Various changes may be made. For example, wireless network 100 may include any number of gNBs and any number of UEs in any suitable arrangement. In addition, gNB 101 may communicate directly with any number of UEs and provide those UEs with wireless broadband access to network 130. Similarly, each gNB 102-103 may communicate directly with network 130 and provide UEs with direct wireless broadband access to network 130. In addition, gNBs 101, 102, and / or 103 may provide access to other or additional external networks, such as an external telephone network or other type of data network.

[0073] As discussed in more detail below, wireless network 100 may have communications facilitated via one or more devices (e.g., UEs 111A to 111C) that may have SL communications with UE 111. UE 111 may communicate directly with UEs 111A to 111C via a collection of SLs (e.g., SL interfaces) to provide sidelink communications, for example, where UEs 111A to 111C are remotely located or otherwise need to facilitate a network access connection (e.g., BS 102) in addition to or in addition to a traditional fronthaul and / or backhaul connection / interface. In one example, UE 111 may communicate directly with UEs 111A to 111C via SL communications with or without support from BS 102. Various UEs (e.g., as depicted by UEs 112 to 116) may be able to communicate one or more times with their other UEs (e.g., UEs 111A to 111C of UE 111).

[0074] Figure 2 An example gNB 102 is shown according to an embodiment of the present disclosure. Figure 2 The embodiment of the gNB 102 shown in FIG. is for illustration only, and Figure 1 gNBs 101 and 103 may have the same or similar configurations. However, gNBs have a variety of configurations, and Figure 2 The scope of this disclosure is not limited to any particular implementation of gNB.

[0075] like Figure 2 As shown, gNB 102 includes multiple antennas 205a-205n, multiple transceivers 210a-210n, a controller / processor 225, a memory 230, and a backhaul or network interface 235. However, the components of gNB 102 are not limited thereto. For example, gNB 102 may include more or fewer components than those described above. In addition, gNB 102 corresponds to Fig.19 base station.

[0076] The transceivers 210a-210n receive incoming radio frequency (RF) signals from the antennas 205a-205n, such as signals transmitted by UEs in the wireless network 100. The transceivers 210a-210n downconvert the incoming RF signals to generate IF or baseband signals. The IF or baseband signals are processed by receive (RX) processing circuits in the transceivers 210a-210n and / or the controller / processor 225, which generate processed baseband signals by filtering, decoding, and / or digitizing the baseband or IF signals. The controller / processor 225 may further process the baseband signals.

[0077] Transmit (TX) processing circuitry in the transceivers 210a-210n and / or the controller / processor 225 receives analog or digital data (such as voice data, web data, email, or interactive video game data) from the controller / processor 225. The TX processing circuitry encodes, multiplexes, and / or digitizes the outgoing baseband data to generate a processed baseband or IF signal. The transceivers 210a-210n up-convert the baseband or IF signal to an RF signal that is transmitted via the antennas 205a-205n.

[0078] The controller / processor 225 may include one or more processors or other processing devices that control the overall operation of the gNB 102. For example, the controller / processor 225 may control the reception of uplink (UL) channels and / or signals and the transmission of downlink (DL) channels and / or signals through the transceivers 210a-210n in accordance with well-known principles. The controller / processor 225 may also support additional functionality, such as more advanced wireless communication functionality. For example, the controller / processor 225 may support beamforming or directional routing operations, in which outgoing / incoming signals from / to multiple antennas 205a-205n are weighted differently to effectively direct the outgoing signals in a desired direction. The controller / processor 225 may support any of a wide variety of other functionality in the gNB 102.

[0079] The controller / processor 225 is also capable of executing programs and other processes resident in the memory 230, such as to support sidelink (SL) initial beam acquisition. The controller / processor 225 may move data into or out of the memory 230 as required by the executing process.

[0080] The controller / processor 225 is also coupled to a backhaul or network interface 235. The backhaul or network interface 235 allows the gNB 102 to communicate with other devices or systems via a backhaul connection or via a network. The interface 235 may support communication via any suitable wired or wireless connection. For example, when the gNB 102 is implemented as part of a cellular communication system (such as a cellular communication system supporting 5G / NR, LTE, or LTE-A), the interface 235 may allow the gNB 102 to communicate with other gNBs via a wired or wireless backhaul connection. When the gNB 102 is implemented as an access point, the interface 235 may allow the gNB 102 to communicate with a larger network (such as the Internet) via a wired or wireless local area network or via a wired or wireless connection. The interface 235 includes any suitable structure that supports communication via a wired or wireless connection, such as Ethernet or a transceiver.

[0081] Memory 230 is coupled to controller / processor 225. A portion of memory 230 may include RAM, and another portion of memory 230 may include flash memory or other ROM.

[0082] although Figure 2 An example of a gNB 102 is shown, but the Figure 2 For example, gNB 102 may include any number of Figure 2 Each component shown in . In addition, Figure 2 The various components in may be combined, further subdivided, or omitted, and additional components may be added according to specific needs.

[0083] Figure 3 An example UE 116 is shown in accordance with an embodiment of the present disclosure. Figure 3 The embodiment of UE 116 shown is for illustration only, and Figure 1 UEs 111-115 may have the same or similar configurations. In addition, when the term "UE" is used herein, a UE may be Figure 1 Any UE among UEs 111-116 in the UE, and the UE may have Figure 3 However, UEs have a variety of configurations, and Figure 3 The scope of the present disclosure is not limited to any particular implementation of a UE.

[0084] like Figure 3As shown, UE 116 includes antenna 305, transceiver 310 and microphone 320. UE 116 also includes speaker 330, processor 340, input / output (I / O) interface (IF) 345, input 350, display 355 and memory 360. Memory 360 includes operating system (OS) 361 and one or more applications 362. However, the components of UE 116 are not limited thereto. For example, UE 116 may include more or fewer components than the above components. In addition, UE 116 corresponds to Fig. 20 UE.

[0085] Transceiver 310 receives incoming RF signals from antenna 305 transmitted by a gNB of wireless network 100 or by other UEs (e.g., one or more of UEs 111-115) on a SL channel. Transceiver 310 downconverts the incoming RF signals to generate an intermediate frequency (IF) or baseband signal. The IF or baseband signal is processed by RX processing circuitry in transceiver 310 and / or processor 340, which generates a processed baseband signal by filtering, decoding, and / or digitizing the baseband or IF signal. The RX processing circuitry transmits the processed baseband signal to speaker 330 (such as for voice data) or is processed by processor 340 (such as for web browsing data).

[0086] The TX processing circuit in the transceiver 310 and / or the processor 340 receives analog or digital voice data from the microphone 320, or receives other outgoing baseband data (such as web data, email, or interactive video game data) from the processor 340. The TX processing circuit encodes, multiplexes, and / or digitizes the outgoing baseband data to generate a processed baseband or IF signal. The transceiver 310 up-converts the baseband or IF signal to an RF signal that is transmitted via the antenna 305.

[0087] The processor 340 may include one or more processors or other processing devices and executes the OS 361 stored in the memory 360 to control the overall operation of the UE 116. For example, the processor 340 may control the reception of DL channels and / or signals or SL channels and / or signals and the transmission of UL channels and / or signals or SL channels and / or signals through the transceiver 310 according to well-known principles. In some embodiments, the processor 340 includes at least one microprocessor or microcontroller.

[0088] The processor 340 is also capable of executing other processes and programs resident in the memory 360. For example, the processor 340 can execute the processes for utilizing and supporting SL initial beam acquisition as described in the embodiments of the present disclosure. The processor 340 can move data into or out of the memory 360 as needed to execute the process. In some embodiments, the processor 340 is configured to execute the application 362 based on the OS 361 or in response to a signal received from the gNB or another SL UE or operator. The processor 340 is also coupled to the I / O interface 345, which provides the UE 116 with the ability to connect to other devices such as laptops and handheld computers. The I / O interface 345 is the communication path between these accessories and the processor 340.

[0089] Processor 340 is also coupled to input 350 including, for example, a touch screen, a keyboard, etc., and display 355. An operator of UE 116 may use input 350 to enter data into UE 116. Display 355 may be a liquid crystal display, a light emitting diode display, or other display capable of presenting text and / or at least limited graphics, such as from a website.

[0090] Memory 360 is coupled to processor 340. A portion of memory 360 may include random access memory (RAM), and another portion of memory 360 may include flash memory or other read-only memory (ROM).

[0091] although Figure 3 An example of UE 116 is shown, but the Figure 3 Make various changes. For example, Figure 3 The various components in may be combined, further subdivided, or omitted, and additional components may be added as required. As a specific example, processor 340 may be divided into multiple processors, such as one or more central processing units (CPUs) and one or more graphics processing units (GPUs). In another example, transceiver 310 may include any number of transceivers and signal processing chains, and may be connected to any number of antennas. In addition, although Figure 3 The UE 116 is shown configured as a mobile phone or smart phone, but the UE may be configured to operate as other types of mobile or stationary devices.

[0092] Figure 4A and Figure 4BExamples of wireless transmit and receive paths 400 and 450 are shown, respectively, according to embodiments of the present disclosure. For example, transmit path 400 may be described as being implemented in a gNB (such as gNB 102), and receive path 450 may be described as being implemented in a UE (such as UE 116). However, it should be understood that receive path 450 may be implemented in a gNB and transmit path 400 may be implemented in a UE. It may also be understood that receive path 450 may be implemented in a first UE and transmit path 400 may be implemented in a second UE to support SL communications. In some embodiments, transmit path 400 and receive path 450 may be configured to support SL initial beam acquisition, as described in embodiments of the present disclosure.

[0093] like Figure 4A As shown, the transmit path 400 includes a channel coding and modulation block 205, a serial to parallel (S to P) block 410, an inverse fast Fourier transform (IFFT) block of size N 415, a parallel to serial (P to S) block 420, an add cyclic prefix block 425, and an upconverter (UC) 430. The receive path 250 includes a downconverter (DC) 455, a remove cyclic prefix block 460, an S to P block 465, a fast Fourier transform (FFT) block of size N 470, a parallel to serial (P to S) block 475, and a channel decoding and demodulation block 480.

[0094] In transmit path 400, channel coding and modulation block 405 receives a set of information bits, applies coding (such as low density parity check (LDPC) coding), and modulates the input bits (such as with quadrature phase shift keying (QPSK) or quadrature amplitude modulation (QAM)) to generate a sequence of frequency domain modulation symbols. Serial to parallel block 410 converts (such as demultiplexes) the serial modulation symbols into parallel data to generate N parallel symbol streams, where N is the IFFT / FFT size used in gNB 102 and UEs (e.g., UEs 111-116). Size N IFFT block 415 performs an IFFT operation on the N parallel symbol streams to generate a time domain output signal. Parallel to serial block 420 converts (such as multiplexes) the parallel time domain output symbols from Size N IFFT block 415 to generate a serial time domain signal. Add cyclic prefix block 425 inserts a cyclic prefix into the time domain signal. The up-converter 430 modulates (such as up-converts) the output of the add cyclic prefix block 425 to an RF frequency for transmission via a wireless channel. The signal may also be filtered at baseband before conversion to RF frequency.

[0095] like Figure 4BAs shown, down converter 455 down-converts the received signal to baseband frequency, and remove cyclic prefix block 460 removes the cyclic prefix to generate a serial time domain baseband signal. Serial to parallel block 465 converts the time domain baseband signal to a parallel time domain signal. FFT block 470 of size N performs an FFT algorithm to generate N parallel frequency domain signals. (P to S) block 475 converts the parallel frequency domain signals to a sequence of modulated data symbols. Channel decoding and demodulation block 480 demodulates and decodes the modulated symbols to recover the original input data stream.

[0096] Each of gNBs 101-103 may implement a transmit path 400 similar to that for transmitting in a downlink to UEs 111-116, and may implement a receive path 450 similar to that for receiving in an uplink from UEs 111-116. Similarly, each of UEs 111-116 may implement a transmit path 400 for transmitting in an uplink to gNB 101-103 and / or for transmitting in a sidelink to another UE, and may implement a receive path 450 for receiving in a downlink from gNB 101-103 and / or for receiving in a sidelink for another UE.

[0097] Figure 4A and Figure 4B Each component in may be implemented using hardware only or a combination of hardware and software / firmware. As a specific example, Figure 4A and Figure 4B At least some components in can be implemented in software, while other components can be implemented by configurable hardware or a mixture of software and configurable hardware. For example, FFT block 470 and IFFT block 415 can be implemented as configurable software algorithms, where the value of size N can be modified according to the implementation.

[0098] In addition, although described as using FFT and IFFT, this is by way of illustration only and should not be construed as limiting the scope of the present disclosure. Other types of transforms may be used, such as discrete Fourier transform (DFT) and inverse discrete Fourier transform (IDFT) functions. It should be understood that for DFT and IDFT functions, the value of variable N may be any integer (e.g., 1, 2, 3, 4, etc.), while for FFT and IFFT functions, the value of variable N may be any integer that is a power of two (e.g., 1, 2, 4, 8, 16, etc.).

[0099] although Figure 4A and Figure 4B Examples of wireless transmit and receive paths 400 and 450 are shown, respectively, but may be Figure 4A and Figure 4B Make various changes. For example, Figure 4A and Figure 4BThe various components in may be combined, further subdivided, or omitted, and additional components may be added according to specific needs. Figure 4A and Figure 4B It is intended to illustrate examples of the types of transmit and receive paths that may be used in a wireless network. Any other suitable architecture may be used to support wireless communications in a wireless network.

[0100] like Figure 5A As shown, in wireless system 500, beam 501 of device 504 can be characterized by beam direction 502 and beam width 503. For example, device 504 (or UE) transmits RF energy in the beam direction and within the beam width. Device 504 receives RF energy in the beam direction and within the beam width. Figure 5A As shown, a device at point A 505 can receive from and transmit to device 504 because point A is within the beam width and direction of the beam from device 504. Figure 5A As shown, the device at point B 506 cannot receive from and transmit to device 504 because point B 506 is outside the beam width and direction of the beam from device 504. Although for illustration purposes, Figure 5A The beams are shown to be two-dimensional (2D), but it will be apparent to one skilled in the art that the beams may be three-dimensional (3D), where the beam direction and beam width are defined in space.

[0101] Figure 5B 5 shows an example of a multi-beam operation 550 according to an embodiment of the present disclosure. For example, the multi-beam operation 550 may be performed by Figure 2 The gNB 102 utilizes. This example is for illustration only, and other embodiments may be used without departing from the scope of the present disclosure.

[0102] In wireless systems, devices can transmit and / or receive on multiple beams. This is called "multi-beam operation." Figure 5B For illustrative purposes, the beams are 2D, but it will be apparent to one skilled in the art that the beams may be 3D, where the beams may be sent to or received from any direction in space.

[0103] Figure 6 An example of a transmitter structure 600 for beamforming according to an embodiment of the present disclosure is shown. In certain embodiments, one or more of the gNB 102 or the UE includes the transmitter structure 600. For example, one or more of the antenna 205 and its associated system or the antenna 305 and its associated system may be included in the transmitter structure 600. This example is for illustration only, and other embodiments may be used without departing from the scope of the present disclosure.

[0104] Thus, embodiments of the present disclosure recognize that Rel-14 LTE and Rel-15 NR support up to 32 CSI-RS antenna ports, which enables an eNB or gNB to be equipped with a large number of antenna elements (such as 64 or 128). Multiple antenna elements can then be mapped to one CSI-RS port. For mmWave bands, although the number of antenna elements can be larger for a given form factor, the number of CSI-RS ports (which can correspond to the number of digital precoding ports) can be limited due to hardware constraints (such as the feasibility of installing a large number of analog-to-digital converters (ADCs) / digital-to-analog converters (DACs) at mmWave frequencies), such as Figure 6 As shown. One CSI-RS port can then be mapped to a large number of antenna elements that can be controlled by a set of analog phase shifters 601. One CSI-RS port can then correspond to a subarray that produces a narrow analog beam through analog beamforming 605. The analog beam can be configured to scan a wider range of angles 620 by changing the phase shifter set across symbols or time slots / subframes. The number of subarrays (equal to the number of RF chains) is proportional to the number of CSI-RS ports N. CSI-PORT The digital beamforming unit 610 spans N CSI-PORT The analog beams are linearly combined to further increase the precoding gain. While the analog beams are broadband (and therefore not frequency selective), the digital precoding can vary across frequency subbands or resource blocks. Receiver operation can be similarly envisioned.

[0105] because Figure 6 The transmitter structure 600 utilizes multiple simulated beams for transmission and reception (wherein one or a small number of simulated beams are selected from a large number of simulated beams, for example, after a training duration that is performed occasionally or periodically), and the term "multi-beam operation" is used to refer to the overall system aspect. For the purpose of description, this includes indicating an assigned DL or UL or SL TX beam (also referred to as "beam indication"), measuring at least one reference signal for calculating and performing beam reporting (also referred to as "beam measurement" and "beam reporting", respectively), and receiving DL or UL or SL transmissions via selecting the corresponding RX beam. Figure 6 The system is also applicable to higher frequency bands, such as >52.6GHz. In this case, the system can use only analog beams. Due to the O2 absorption loss near the 60GHz frequency (additional loss of ~10dB per 100m distance), more and narrower analog beams (and therefore more radiators in the array) are needed to compensate for the additional path loss.

[0106] The text and drawings are provided as examples only to help the reader understand the present disclosure. They are not intended to and should not be interpreted as limiting the scope of the present disclosure in any way. Although certain embodiments and examples have been provided, it will be apparent to those skilled in the art based on the disclosure herein that changes may be made to the illustrated embodiments and examples without departing from the scope of the present disclosure. The transmitter structure 600 for beamforming is for illustration only, and other embodiments may be used without departing from the scope of the present disclosure.

[0107] Figure 7 FIG. 7 is a flowchart showing an example process 700 for establishing a layer 2 link for unicast mode of V2X communication over a PC5 reference point according to an embodiment of the present disclosure. For example, the process 700 may be performed by Figure 1 Multiple UEs among UEs 111-116 perform to perform SL communication. This example is for illustration only, and other embodiments may be used without departing from the scope of the present disclosure.

[0108] Process 700 begins at step 710, where the UE determines a destination Layer 2 ID for signaling reception for PC5 unicast link establishment. This is determined as specified in clause 5.6.1.4 of TS23.387. The destination Layer 2 ID is configured with the UE as specified in clause 5.1.2.1 of TS23.387. In step 720, the V2X application layer in UE-1 provides application information for PC5 unicast communication. In step 730, UE-1 sends a direct communication request (DCR) to initiate the unicast Layer 2 link establishment process, and sends the DCR message via PC5 broadcast or unicast using the source Layer 2 ID and the destination Layer 2 ID. In step 740, the target UE, or a UE interested in using the announced V2X service type with UE-1 over a PC5 unicast link, establishes security with UE-1 by responding. In step 750, the target UE, which has successfully established security with UE-1, sends a direct communication accept message to UE-1. In step 760, V2X service data is sent via the established unicast link.

[0109] The time unit of DL signaling, UL signaling or SL signaling on a cell is one symbol. A symbol belongs to a time slot including multiple symbols (such as 14 symbols). A time slot can also be used as a time unit. A bandwidth (BW) unit is called a resource block (RB). One RB includes multiple subcarriers (SC). For example, a time slot can have a duration of one millisecond, and the RB can have a bandwidth of 180kHz and include 12 SCs with an inter-SC spacing of 15kHz. As another example, a time slot can have a duration of 0.25 milliseconds and include 14 symbols, and the RB can have a BW of 720kHz and include 12 SCs with an SC spacing of 60kHz. The RB in one symbol of a time slot is called a physical RB (PRB) and includes multiple resource elements (REs). A time slot can be a complete DL time slot, or a complete UL time slot, or a mixed time slot, similar to a special subframe in a time division duplex (TDD) system (see also literature and standards [1]). In addition, a time slot can have symbols for SL communication. A UE may be configured with one or more bandwidth parts (BWPs) of the system BW for transmission or reception of signals or channels.

[0110] SL signals and channels are sent and received on subchannels within a resource pool, which is a collection of time-frequency resources used for SL transmission and reception within a SL BWP. SL channels include a physical SL shared channel (PSSCH) that transmits data information and second-stage / partial SL control information (SCI), a physical SL control channel (PSCCH) that transmits first-stage / partial SCI for scheduling transmission / reception of PSSCH, a physical SL feedback channel (PSFCH) that transmits hybrid automatic repeat request acknowledgment (HARQ-ACK) information in response to correct (ACK value) or incorrect (NACK value) transmission block reception in the corresponding PSSCH, the PSFCH can also transmit conflict information, and a physical SL broadcast channel (PSBCH) that transmits system information to assist SL synchronization. The SL signal includes a demodulation reference signal (DM-RS) multiplexed in PSSCH or PSCCH transmission to assist data or SCI demodulation, a channel state information reference signal (CSI-RS) for channel measurement, a phase tracking reference signal (PT-RS) for tracking carrier phase, and a SL primary synchronization signal (S-PSS) and a SL secondary synchronization signal (S-SSS) for SL synchronization. The SCI may include two parts / stages corresponding to two corresponding SCI formats, where, for example, a first SCI format is multiplexed on the PSCCH, and a second SCI format is multiplexed with SL data on the PSSCH, and the PSSCH is sent in the physical resources indicated by the first SCI format.

[0111] The SL channel can operate in different cast modes. In unicast mode, PSCCH / PSSCH transmits SL information from one UE to only one other UE. In groupcast mode, PSCCH / PSSCH transmits SL information from one UE to a group of UEs within a (pre)configured set. In broadcast mode, PSCCH / PSSCH transmits SL information from one UE to all surrounding UEs. In NR Release 16, there are two resource allocation modes for PSCCH / PSSCH transmission. In resource allocation mode 1, the gNB schedules the UE on SL and transmits scheduling information to the UE transmitting on SL via a DCI format (e.g., DCI format 3_0) sent from gNB 102 on DL. In resource allocation mode 2, the UE schedules SL transmission. SL transmission can operate within network coverage, where each UE is within the communication range of the gNB, outside network coverage, where all UEs do not communicate with any gNB, or within partial network coverage, where only some UEs are within the communication range of the gNB.

[0112] In case of groupcast PSCCH / PSSCH transmission, the UE may be (pre-)configured with one of two options for reporting HARQ-ACK information by the UE.

[0113] In one option of HARQ-ACK reporting, if, for example, the UE detects an SCI format that schedules TB reception via the corresponding PSSCH, the UE may attempt to decode the TB in the PSSCH reception. If the UE fails to correctly decode the TB, the UE multiplexes a NACK in the PSFCH transmission. In this option, when the UE correctly decodes the TB, the UE does not send a PSFCH with an ACK. When a UE sending a PSSCH detects a NACK in the PSFCH reception, the UE is able to send another PSSCH with the TB (a retransmission of the TB).

[0114] In another option of HARQ-ACK reporting, if, for example, the UE detects an SCI format that schedules the corresponding PSSCH, the UE can attempt to decode the TB. If the UE decodes the TB correctly, the UE multiplexes the ACK in the PSFCH transmission; otherwise, if the UE does not decode the TB correctly, the UE multiplexes the NACK in the PSFCH transmission. When the UE sending the PSSCH does not detect an ACK in the PSFCH reception, such as when the UE detects a NACK or does not detect a PSFCH reception, the UE can send another PSSCH using the TB.

[0115] The sidelink resource pool includes a time slot set / pool and a RB set / pool for sidelink transmission and sidelink reception. The time slot set belonging to the sidelink resource pool can be composed of , and can be configured, for example, using at least a bitmap. MAX is the number of SL time slots in the resource pool within a 1024-frame frame. In the frequency domain used for sidelink transmission, there are N subCH consecutive subchannels, where N subCH Provided by higher layer parameters. Subchannel m, where m is in the range of 0 to N subCH -1, by n subCHsize The set of consecutive PRBs is given by: PRB =n subCHstart +m·n subCHsize +j, where j = 0, 1, ..., n subCHsize -1,n subCHstart and n subCHsize Provided by higher layer parameters.

[0116] For resource (re)selection or re-evaluation in time slot n, the UE may determine the resource selection window [n+T 1 , n+T 2 ], so that the single-slot resource R used for transmission is x,y Defined as L subCH A set of consecutive subchannels x+i, where where i = 0, 1, ..., L subCH -1. T 1 Determined by the UE, in, is the PSSCH processing time, e.g. as defined in the document and standard [4]. 2 Determined by UE, so that T 2min ≤T 2 ≤Remaining Packet Delay Budget, as long as T 2min < remaining packet delay budget, otherwise T 2 is equal to the remaining packet delay budget. 2min It is configured by higher layers and depends on the priority of the SL transmission.

[0117] The time slots of the SL resource pool are determined as follows.

[0118] 1. Let the set of time slots that can belong to a resource be represented by: in, And 0≤i <T max. μ is the subcarrier spacing configuration. For 15kHz subcarrier spacing μ=0. For 30kHz subcarrier spacing μ=1. For 60kHz subcarrier spacing μ=2. For 120kHz subcarrier spacing μ=3. The slot index is associated with slot #0 of system frame number (SFN) #0 of the serving cell or downlink frame number (DFN) #0. The slot set includes all slots except the following:

[0119] a. Configure N for SL SS / PBCH block (S-SSB) S-SSB time slots.

[0120] Bn nonSL time slots, where at least one SL symbol is not semi-statically configured as a UL symbol by a higher layer parameter tdd-UL-DL-ConfigurationCommon or sl-TDD-Configuraulion. In the SL time slot, the Yth, (Y+1)th, ..., (Y+X-1)th OFDM symbols are SL symbols, where Y is determined by a higher layer parameter sl-StartSymbol and X is determined by a higher layer parameter sl-LengthSymbols.

[0121] cN reserved The reserved time slots are determined so that the set The time slot in the bitmap is the length (L bitmap ), where bitmap Configured by higher layers. The reserved slots are determined as follows:

[0122] i.let The range is 0...2 μ The set of slots in ×10240-1, excluding S-SSB slots and non-SL slots. The slots are arranged in ascending order of slot index.

[0123] ii. The number of reserved time slots is given by: N reserved =(2 μ ×10240-N S-SSB -N nonSL )mod L bitmap .

[0124] iii. Reserved time slot l r Given by: Where m = 0, 1, ..., N reserved -1

[0125] T max Given by the following formula: T max =2 μ×10240-N S-SSB -N nonSL -N reserved .

[0126] 2. The time slots are arranged in ascending order of the time slot index.

[0127] 3. The set of time slots belonging to the SL resource pool Determined as follows:

[0128] a. Each resource pool has a length of L bitmap The corresponding bitmap

[0129] b. If Time slot Belongs to the SL resource pool

[0130] c. The remaining time slots are from 0, 1, ... T' MAX -1 starts indexing continuously. MAX is the number of remaining time slots in the set.

[0131] The time slots may be numbered (indexed) as physical time slots or logical time slots, where physical time slots include all time slots numbered sequentially, while logical time slots include only sequentially numbered time slots allocated to a sidelink resource pool as described herein. rsvp (in milliseconds) to the logical time slot P r ′ svp The conversion is given by: (See literature and standards [4]).

[0132] For resource (re)selection or re-evaluation in time slot n, the UE may determine the resource selection window [n+T 1 , n+T 2 ], so that the single-slot resource R used for transmission is x,y Defined as L subCH The set of subchannels x+i, where where i = 0, 1, ..., L subCH -1. T 1 Determined by UE 116 such that in, is the PSSCH processing time, e.g. as defined in the document and standard [4]. 2 Determined by UE, so that T 2min ≤T 2 ≤ Remaining packet delay budget, as long as T 2min < remaining packet delay budget, otherwise T 2is equal to the remaining packet delay budget. 2min Configured by higher layers and depends on the priority of the SL transmission.

[0133] Resource (re)selection is a two-step process. The first step (e.g., performed in the physical layer) is to identify candidate resources within the resource selection window. Candidate resources are resources that belong to a resource pool, but exclude resources that were previously reserved or potentially reserved by other UEs (e.g., resource exclusion). The excluded resources are based on the SCI decoded in the sensing window, and the UE measures a SL RSRP that exceeds a threshold for the SCI. The threshold depends on the priority indicated in the SCI format and the priority of the SL transmission. Therefore, sensing within the sensing window involves decoding the first stage SCI and measuring the corresponding SL RSRP, where the SL RSRP can be based on PSCCH DMRS or PSSCH DMRS. Sensing is performed on time slots where the UE does not send SL. The excluded resources are based on reserved transmissions or semi-persistent transmissions or any reserved or semi-persistent transmissions that may conflict with the excluded resources. The candidate resources identified after resource exclusion are provided to higher layers.

[0134] The second step (eg, performed in higher layers) is to select or reselect a resource from the identified candidate resources for PSSCH / PSCCH transmission.

[0135] During the first step of the resource (re)selection process, the UE may monitor the sensing window The UE monitors the time slots in the sidelink resource pool that are not used for the UE's transmission. is the sensing processing delay time defined in the document and standard [4]. In order to determine the candidate single-slot resource set to be reported to the higher layer, the UE excludes (e.g., resource excludes) the following from the available single-slot resource set for SL transmission in the resource pool and in the resource selection window:

[0136] 1. Single time slot resource R x,y , so that for any time slot Not monitored within the sensing window with assumed received SCI format 1-0, where "resource retention period" is set to any periodic value allowed by the higher layer parameter reseverationPerioAllowed, and indicating all subchannels of the resource pool in this timeslot, meet the conditions herein.

[0137] 2. Single time slot resource R x,y , so that for any received SCI within the sensing window:

[0138] a. The associated L1-RSRP measurement is above a (pre-)configured SL-RSRP threshold, where the SL-RSRP threshold depends on the priority indicated in the received SCI and the priority of the SL transmission for which resources are being selected.

[0139] b.Time slot or if the "Resource Reservation Field" is present in the received SCI, it is assumed that the resource is reserved in the time slot receives the same SCI as A collection of overlapping resource blocks.

[0140] iq=1,2,…,Q,where

[0141] ii. If P rsvp_RX ≤T scal and T scal T is in milliseconds 1 .

[0142] Otherwise Q=1

[0143] ●If n belongs to Otherwise n′ belongs to the set The first time slot after time slot n.

[0144] iii.j=0,1,…,C resel -1

[0145] iv.P rsvp_RX is the resource reservation period indicated in the received SCI in the physical time slot, and P r ′ svp_Rx is the value converted to a logical time slot.

[0146] vP r ′ svp_Tx It is the resource reservation period for SL transmission, in which resources are reserved in the logical time slot.

[0147] 3. If the candidate resource is less than the number specified by the higher layer parameter sl_TxPrecentageList(prio TX ) (This parameter depends on the priority of SL transmission prio TX ) given a (pre)configured percentage, such as 20% of the total available resources within the resource selection window, the (pre)configured SL-RSRP threshold is increased by a predetermined amount, for example 3dB.

[0148] The NR sidelink introduces two new procedures for Mode 2 resource allocation; re-evaluation and pre-emption.

[0149] A re-evaluation check occurs when the UE checks the availability of a pre-selected SL resource before first signaling the resource in SCI format, and reselects a new SL resource if necessary. For a pre-selected resource to be signaled for the first time in slot m, the UE shall at least 3 Reassessment checks are performed in the . Reassessment checks include:

[0150] 1. Perform the first step of the SL resource selection process as defined in the 3GPP specifications (i.e., documents and standards [4]), which involves identifying a set of candidate (available) side link resources in the resource selection window as described herein.

[0151] 2. If the pre-selected resources are available in the set of candidate sidelink resources, the resources are used / signaled for sidelink transmission.

[0152] 3. Otherwise, if the pre-selected resource is not available in the candidate side link resource set, a new side link resource is reselected from the candidate side link resource set.

[0153] The preemption check occurs when the UE checks the availability of the pre-selected SL resource that has been previously signaled and reserved in SCI format, and reselects a new SL resource if necessary. For the pre-selected and reserved resource to be signaled in time slot m, the UE shall at least 3 When higher layers enable preemption checking, preemption checking includes:

[0154] (a) The first step of the SL resource selection process as defined in the 3GPP specifications (i.e., documents and standards [4]) is performed, which involves identifying a set of candidate (available) side link resources in the resource selection window as described herein.

[0155] (b) If the pre-selected and reserved resources are available in the set of candidate sidelink resources, the resources are used / signaled for sidelink transmission.

[0156] (c) Otherwise, the pre-selected and reserved resources are not available in the candidate sidelink resource set. RX The associated SCI,resource is excluded from the candidate resource set. Let the priority value of the side link resource to be checked for preemption be P TX .

[0157] (d) If the priority value P RX is less than the threshold configured by the higher layer and the priority value P RX Less than the priority value P TXThe pre-selected and reserved sidelink resource is preempted. A new sidelink resource is reselected from the candidate sidelink resource set. Note that a lower priority value indicates a higher priority service.

[0158] (e) Otherwise, the resources are used / signaled for sidelink transmission.

[0159] As described herein, the monitoring process for resource (re)selection during the sensing window requires receiving and decoding the SCI format and measuring the SL RSRP during the sensing window. This reception and decoding process and measuring the SL RSRP increase the processing complexity and power consumption of the UE for sidelink communication and require the UE to have receiving circuitry on the SL for sensing, even if the UE only transmits on the sidelink and does not receive on the sidelink. The sensing process is called full sensing.

[0160] 3GPP Release 16 is the first NR release to include sidelink through work item "5G V2X with NR Sidelink", and the mechanisms introduced are focused on V2X and can be used for public safety when service requirements can be met. Release 17 extends sidelink support to more use cases through work item "NR Sidelink Enhancements" (RP-201385). Goals for Rel-17 SL include resource allocation enhancements for reduced power consumption, as well as enhanced reliability and reduced latency.

[0161] Rel-17 introduces low power resource allocation. The low power resource allocation scheme includes partial sensing and random resource selection. If the SL transmission from the UE is periodic, the partial sensing can be based on periodic based partial sensing (PBPS), and / or continuous partial sensing (CPS). If the SL transmission from the UE is non-periodic, if the resource pool supports periodic reservation (i.e., sl_multiReserveResource is enabled), the partial sensing can be based on CPS and PBPS. When the UE performs PBPS, the UE selects a set of Y time slots (Y ≥ Y) within the resource selection window corresponding to the PBP. min ), where Y min Provided by the higher layer parameter minNumCandidateSlotsPeriodic. Monitoring time slots, where is one of the Y selected candidate time slots. The periodicity value of PBPS for sensing, i.e., P reserve A subset of the resource reservation periods allowed in the resource pool provided by the higher layer parameter sl-ResourceReservePeriodList. reserve Provided by the higher layer parameter periodicSensingOcasionReservePeriodList.reserve Not configured, P reserve Includes all periods in sl-ResourceReservePeriodList. The UE monitors k sensing occasions determined by additionalPeriodicSensingOcasion, as described herein, and no earlier than n–T 0 For a given period P reserve If additionalPeriodicSensingOccasion is not (pre)configured, the value of k corresponds to an interval earlier than and, if additionalPeriodicSensingOccasion is (pre)configured, additionally includes the value of k corresponding to the last periodic sensing occasion before the most recent periodic sensing occasion. is the first time slot of the Y candidate time slots selected for PBPS. When the UE performs CPS, the UE 116 selects Y' (Y' ≥ Y') within the resource selection window corresponding to the CP. min ) time slots, where Y′ min The CPS sensing window is at least The M logical time slots before (the first of Y' candidate time slots) start and end at

[0162] According to an embodiment of the present disclosure, without loss of generality, UE-A is the UE 116 that initiates a unicast session. That is, UE-A is the UE that sends a direct communication request (DCR) (also called a link establishment message) for link establishment to UE-B. The roles of UE-A and UE-B can be interchanged.

[0163] Embodiments of the present disclosure recognize that Rel-17 introduces inter-UE coordination (IUC) to enhance the reliability of resource allocation and reduce latency, where SL UEs exchange information with each other via a side link to assist in the resource allocation mode 2 (re)selection process. UE-A provides information to UE-B, and UE-B uses the provided information for its resource allocation mode 2 (re)selection process. IUC is designed to solve problems of distributed resource allocation, such as: (1) the hidden node problem, where UE-B is transmitting to UE-A and UE-B cannot sense or detect transmissions from UE-C that interfere with its transmissions to UE-A, (2) the exposed node problem, where UE-B is transmitting to UE-A and UE-B senses or detects transmissions from UE-C and avoids resources used or reserved by UE-C, but UE-C does not cause interference at UE-A, (3) the persistent collision problem, and (4) the half-duplex problem, where UE-B transmits to UE-A in the same time slot in which UE-A is transmitting, UE-A will miss the transmission from UE-B because UE-A cannot receive and transmit in the same time slot.

[0164] There are two schemes for inter-UE coordination.

[0165] In one example, in scheme 1, UE-A may provide another UE-B with an indication of resources that are preferably included in the (re)selected resources of UE-B, or an indication of non-preferred resources that are excluded for the (re)selected resources of UE-B. When given preferred resources, UE-B may use only those resources for its resource (re)selection, or UE-B may combine them with resources identified by its own sensing process (e.g., by finding the intersection of the two sets of resources) for its resource (re)selection. When given non-preferred resources, UE-B may exclude these resources from the resources identified by its own sensing process for its resource (re)selection. The transmission of coordination information (e.g., IUC message) sent by UE-A to UE-B and the transmission of coordination information request (e.g., IUC request) sent by UE-B to UE-A are sent in a MAC-CE message and, if supported by the UE, may also be sent in a second stage SCI format (SCI format 2-C). The benefit of using the second stage SCI is reduced latency. The IUC message from UE-A to UE-B may be sent independently or in combination with other SL data. The coordination information (IUC message) may be in response to a request from UE-B or due to conditions at UE-A. The IUC request is unicast from UE-B to UE-A, and in response, UE-A sends the IUC message to UE-B in unicast mode. The IUC message sent as a result of internal conditions at UE-A may be unicast to UE-B when the IUC message includes preferred resources, or may be unicast, multicast or broadcast to UE-B when the IUC message includes non-preferred resources. Taking into account the SL-RSRP measurement of the sensed data and the priority of the sensed data (i.e., the priority field of the PSCCH decoded during sensing and the priority of the service sent by UE-B in the case of request-based IUC or the configured priority in the case of conditional-based IUC), UE-A may determine the preferred or non-preferred resources for UE-B based on its own sensing. Non-preferred resources for UE-B may also be determined to avoid a half-duplex problem, where UE-A cannot receive data from UE-B in the same time slot that UE-A is transmitting.

[0166] In another example, UE-A may provide another UE-B with an indication that resources reserved for UE-B's transmissions (regardless of whether UE-A is the destination UE for those resources) conflict with transmissions from another UE. UE-A determines the conflicting resources based on the priority and RSRP of the transmissions involved in the conflict. UE-A may also determine the presence of a conflict due to a half-duplex problem, where UE-A cannot receive reserved resources from UE-B while UE-A is transmitting. When UE-B receives an indication of a conflict for the reserved resources, UE-B may reselect new resources to replace them.

[0167] The contention information from UE-A is sent in a PSFCH channel that is (pre-)configured separately from the PSFCH for SL-HARQ operation.The timing of the PSFCH channel carrying the contention information may be based on the SCI indicating the reserved resources or based on the reserved resources.

[0168] In both schemes, UE-A may identify resources based on a number of criteria based on the SL-RSRP of the resource in question as a function of traffic priority, and / or whether UE-A will not be able to receive transmissions from UE-B due to performing its own transmissions (i.e., half-duplex issues). The purpose of this information exchange is to give UE-B information about the resource occupancy obtained by UE-A, which UE-B may not be able to determine on its own due to hidden nodes, exposed nodes, ongoing conflicts, etc.

[0169] Embodiments of the present disclosure recognize that Rel 18 evaluates further evolution of the NR SL air interface for operation in unlicensed bands, beam-based operation in FR2, SL carrier aggregation, and co-channel coexistence between LTE SL and NR SL.

[0170] On the (Uu) interface, the beam is determined by the TCI state or spatial relationship information, which establishes a quasi-co-location (QCL) relationship or spatial relationship between the source reference signal (e.g., SSB and / or CSI-RS) and the target reference signal, and the spatial relationship information establishes an association with the source reference signal (such as SSB, CSI-RS or SRS). In either case, the ID of the source reference signal identifies the beam.

[0171] Terms such as TCI, TCI status, SpatialRelationInfo, target RS, reference RS and other terms are used for illustrative purposes and are therefore not normative. Other terms referring to the same functionality may also be used.

[0172] Embodiments of the present disclosure recognize that Rel-17 introduces a unified TCI framework, where a unified or primary or main or indicated TCI state is signaled or indicated to the UE. The unified, primary, main or indicated TCI state may be one of the following:

[0173] 1. In case of joint TCI state indication, where the same beam is used for DL ​​and UL channels, the joint TCI state can be used for at least UE-specific DL channels and UE-specific UL channels.

[0174] 2. In case of separate TCI state indication, where different beams are used for DL ​​and UL channels, the DL TCI state may be used at least for the UE-dedicated DL channel.

[0175] 3. In case of separate TCI state indication, where different beams are used for DL ​​and UL channels, the UL TCI state may be used at least for the UE-specific UL channel.

[0176] The unified (primary or primary or indicated) TCI state is the DL or joint TCI state for UE-dedicated reception on the physical downlink shared channel (PDSCH) / physical downlink control channel (PDCCH), and the CSI-RS to which the indicated TCI state is applied and / or the UL or joint TCI state for dynamic grant / configuration grant is based on PUSCH, PUCCH and SRS to which the indicated TCI state is applied.

[0177] The unified TCI framework is applicable to intra-cell beam management, where the TCI state has a source RS that is directly or indirectly associated with the SSB of the serving cell through a quasi-co-location relationship (e.g., a spatial relationship) (e.g., the TCI state is associated with the TRP of the serving cell). The unified TCI state framework is also applicable to inter-cell beam management, where the TCI state may have a source RS that is directly or indirectly associated with the SSB of a cell having a physical cell identifier (PCI) different from the PCI of the serving cell through a quasi-co-location relationship (e.g., a spatial relationship) (e.g., the TCI state is associated with the TRP of a cell having a PCI different from the PCI of the serving cell). In Rel-17, a TCI state associated with a cell having a PCI different from the PCI of the serving cell may be used to receive and / or send a UE-dedicated channel. When a common channel may be received and / or sent using a TCI state associated with a serving cell (e.g., not associated with a cell having a PCI different from the PCI of the serving cell), the common channel may include:

[0178] a) A channel (e.g., System Information Block 1 (SIB1)) that carries system information with DL allocations carried by DCI in PDCCH with CRC scrambled by SI-RNTI and sent in the Type0-PDCCH Common Search Space (CSS) set.

[0179] b) A channel that carries other system information with DL allocations carried by DCI in PDCCH with CRC scrambled by SI-RNTI and sent in a Type0A-PDCCH CSS set.

[0180] c) A channel carrying paging or short messages with DL allocations carried by DCI in PDCCH with CRC scrambled by P-RNTI and sent in Type2-PDCCH CSS set.

[0181] d) Channels carrying Random Access Channel (RACH) related channels with DL assignments or UL grants carried by DCI in PDCCH with CRC scrambled by Random Access Radio Network Temporary Identifier (RA-RNTI) or Temporary C(TC)-RNTI and sent in Type 1-PDCCH CSS set.

[0182] A DL-related DCI format (e.g., DCI format 1_1 or DCI format 1_2) with or without DL allocation may indicate a TCI state code point to the UE through the field "Transmission Configuration Indication", where the TCI state code point may be one of a DL TCI state, a UL TCI state, a joint TCI state, or a pair of a DL TCI state and a UL TCI state. The TCI state code point is activated by medium access control (MAC) control element (CE) signaling.

[0183] A QCL relation can be a quasi-position with respect to one or more of the following relations (literature and standards [4]):

[0184] a) Type A, {Doppler shift, Doppler spread, average delay, delay spread}

[0185] b) Type B, {Doppler shift, Doppler spread}

[0186] c) Type C, {Doppler shift, average delay}

[0187] d) Type D, {spatial Rx parameters}

[0188] Additionally, the QCL relationship may also provide a spatial relationship for the UL channel, e.g., the DL source reference signal provides information about a spatial domain filter to be used for UL transmission, or the UL source reference signal provides a spatial domain filter to be used for UL transmission, e.g., the same spatial domain filter is used for both the UL source reference signal and the UL transmission.

[0189] The unified (primary or primary or indicated) TCI state is applicable at least to UE-specific DL and UL channels. The unified (primary or primary or indicated) TCI can also be applied to other DL and / or UL channels and / or signals, such as non-UE-specific channels and sounding reference signals (SRS).

[0190] A “reference RS” corresponds to a set of characteristics of a DL beam or a UL TX beam, such as direction, precoding / beamforming, number of ports, etc.

[0191] On the Uu interface, the TCI state can be used for beam indication. It may refer to a DL TCI state for a downlink channel (e.g., PDCCH and PDSCH), an uplink TCI state for an uplink channel (e.g., PUSCH or PUCCH), a joint TCI state for downlink and uplink channels, or a separate TCI state for uplink and downlink channels. The TCI state may be common across multiple component carriers, or may be a separate TCI state for a component carrier or a set of component carriers. The TCI state may be gNB or UE panel specific or common across panels. In some examples, the uplink TCI state may be replaced by an SRS resource indicator (SRI).

[0192] Figure 8 800 according to an embodiment of the present disclosure. For example, the signaling 800 may be Figure 2 Initiated by BS 102 in and by UE (e.g., Figure 1 UE 111-116), and in particular, transceiver 310. This example is for illustration only, and other embodiments may be used without departing from the scope of the present disclosure.

[0193] A set of TCI states with N elements may be configured / updated to the UE via higher layer RRC signaling. In one example, the DL and joint TCI states are configured by a higher layer parameter DLorJoint-TCIState, where the number of DL and joint TCI states is N. DJ The UL TCI state is configured by the higher layer parameter UL-TCIState, where the number of UL TCI states is N. U . N = N DJ +N U , where N is the total number of configured TCI states. DLorJoint-TCIState may include a DL or joint-TCI state belonging to a serving cell, for example, the source RS of the TCI state is associated with the serving cell (the PCI of the serving cell). In addition, a DL or joint-TCI state may be associated with a cell having a PCI different from the PCI of the serving cell, for example, the source RS of the TCI state is associated with a cell having a PCI different from the PCI of the serving cell. UL-TCIState may include a UL TCI state belonging to a serving cell, for example, the source RS of the TCI state is associated with the serving cell (the PCI of the serving cell). In addition, a UL TCI state may be associated with a cell having a PCI different from the PCI of the serving cell, for example, the source RS of the TCI state is associated with a cell having a PCI different from the PCI of the serving cell.

[0194] MAC CE signaling includes activating a subset of M (M≤N) TCI states or TCI state code points from a set of N TCI states, where the DCI for the indication of the TCI state is signaled in the "Transmission Configuration Indication" field. The code point may include one TCI state (e.g., DL TCI state, UL TCI state, or joint (DL and UL) TCI state). Alternatively, the code point may include two TCI states (e.g., DL TCI state and UL TCI state). L1 control signaling (i.e., downlink control information (DCI)) updates the TCI state of the UE, where the DCI includes a "Transmission Configuration Indication" (beam indication) field, for example, with m bits (such that: M≤2 m ), the TCI state corresponds to the code point signaled by the MAC CE. The DCI for indicating the TCI state may be a DL-related DCI format (eg, DCI format 1_1 or DCI format 1_2), with or without DL allocation.

[0195] Embodiments of the present disclosure describe initial beam acquisition for SL in FR2 during DCR (e.g., during link establishment). A first UE (e.g., UE-A) wants to establish a unicast link with a second UE (e.g., UE-B). UE-A sends a DCR (e.g., a link establishment message) to UE-B. A communication request is sent from UE-A on multiple UE-ASL transmit beams (e.g., transmit beam scanning). UE-B receives the communication request and responds, indicating the UE-A SL transmit beam for subsequent communications. The present disclosure evaluates aspects related to the transmission of DCR from UE-A on multiple UE-ASL transmit beams, the reception process of the DCR at UE-B, and the signaling of the beam for subsequent communications (e.g., the UE-ASL transmit beam preferred by UE-B).

[0196] Embodiments of the present disclosure recognize that Release 18 evaluates further evolution of the NR SL air interface for operation in unlicensed bands, beam-based operation in FR2, SL carrier aggregation, and co-channel coexistence between LTE SL and NR SL. One of the key features of NR is its ability to support beam-based operation. This is particularly important for operation in FR2, which suffers from higher propagation losses. In Rel-16 and Rel-17, the main focus of developing SL was FR1. In fact, the frequency bands supported for SL in Rel-16 and Rel-17 are all sub-6 GHz frequencies (bands n14, n38, n47, and n79). One of the goals of Rel-18 is to extend SL to FR2, and SL supports SL Phase Tracking Reference Signal (PTRS), which is an important feature to support operation in FR2, i.e., beam management is missing. In the present disclosure, we evaluate aspects related to initial beam acquisition: (1) Transmission of DCR (e.g., link establishment message) from UE-A on multiple UE-A SL transmit beams (e.g., transmit beam scanning). (2) The reception process of DCR at UE-B. (3) Signaling of beams (e.g., UE-B prefers the UE-ASL transmission beam for subsequent communications).

[0197] Aspects, features and advantages of embodiments of the present disclosure will be apparent from the following detailed description simply by illustrating a number of specific embodiments and implementations, including the best mode. Embodiments of the present disclosure are also capable of other and different embodiments, and several details thereof may be modified in various obvious respects, all without departing from the spirit and scope of the present disclosure. Therefore, the drawings and description are to be regarded as illustrative in nature, and not restrictive. Embodiments of the present disclosure are shown by way of example and not limitation in the figures of the accompanying drawings.

[0198] The text and drawings are provided as examples only to help the reader understand the embodiments of the present disclosure. They are not intended to and should not be interpreted as limiting the scope of the embodiments of the present disclosure in any way. Although certain embodiments and examples have been provided, it will be apparent to those skilled in the art based on the disclosure herein that the illustrated embodiments and examples may be changed without departing from the scope of the present disclosure.

[0199] The flowcharts illustrate example methods that can be implemented according to the principles of the present disclosure, and various changes can be made to the methods illustrated in the flowcharts herein. For example, although shown as a series of steps, the various steps in each figure can overlap, occur in parallel, occur in a different order, or occur multiple times. In another example, a step can be omitted or replaced by another step.

[0200] In SL, a "reference RS" may correspond to a set of characteristics of a SL beam, such as direction, precoding / beamforming, number of ports, etc. This may correspond to a SL receive beam or a SL transmit beam. At least two UEs are involved in SL communication. We refer to the first UE as UE-A and the second UE as UE-B. In one example, UE-A is sending SL data on PSSCH / PSCCH and UE-B is receiving SL data on PSSCH / PSCCH.

[0201] For mmWave bands (or FR2) or for higher frequency bands where multi-beam operation is particularly relevant (such as >52.6GHz), the transmit-receive process includes a receiver in a second UE (e.g., UE-B) selecting a receive (RX) beam for a given TX beam from a first UE (e.g., UE-A). During initiation of a communication session between UE-A and UE-B, a beam pair for communication from UE-A to UE-B is determined, i.e., the transmit beam from UE-A is paired with the receive beam from UE-B. A beam pair for communication from UE-B to UE-A is also determined, i.e., the transmit beam from UE-B is paired with the receive beam from UE-A.

[0202] In the present disclosure, a beam is also referred to as a spatial domain filter. For example, a transmit beam is a spatial domain transmit (or transmit) filter, and a receive beam is a spatial domain receive (or receive) filter.

[0203] In the present disclosure, RRC signaling (e.g., configuration performed via RRC signaling) includes RRC signaling on the Uu interface, which may be RRC signaling based on a system information block (SIB) (e.g., SIB1 or other SIBs) or RRC dedicated signaling sent to a specific UE, and / or PC5-RRC signaling on a PC5 or SL interface.

[0204] In the present disclosure, MAC CE signaling includes MAC CE signaling on the Uu interface, and / or MAC CE signaling on the PC5 or SL interface.

[0205] In the present disclosure, L1 control signaling includes L1 control signaling on a Uu interface, which may include DL control information (e.g., DCI on PDCCH) and / or UL control information (e.g., UCI on PUCCH or PUSCH), and / or SL control information on a PC5 or SL interface, which may include first-stage sidelink control information (e.g., first-stage SCI on PSCCH), second-stage sidelink control information (e.g., second-stage SCI on PSSCH) and / or feedback control information (e.g., control information carried on PSFCH).

[0206] In the present disclosure, a beam report or a beam measurement report may be a periodic report (e.g., preconfigured or configured by a higher layer), a semi-persistent report activated and / or deactivated by MAC CE signaling and / or L1 control signaling, or a non-periodic report triggered by L1 control signaling and / or MAC CE signaling.

[0207] In the present disclosure, a container of a report (e.g., a beam report (or beam measurement report) or a beam indication message) may be:

[0208] a. MAC CE report. For example, MAC CE report can reuse MAC CE CSI report on SL PC5 interface.

[0209] b. SCI report container. The SCI report container can be a first-stage SCI (e.g., transmitted by PSCCH) and / or a second-stage SCI (e.g., transmitted by PSSCH). In one example, the second-stage SCI is a standalone second-stage SCI in PSSCH, where there is no sidelink shared channel (SL-SCH) in PSSCH. In another example, the second-stage SCI is multiplexed with a MAC CE carrying reports in PSSCH without other SL data. In yet another example, the second-stage SCI is multiplexed with a MAC CE carrying reports and other SL data in PSSCH. In yet another example, the second-stage SCI is multiplexed with other SL data (e.g., in SL-SCH) in PSSCH.

[0210] c. PSFCH report container. In one example, the PSFCH can be redesigned to carry more than one bit of information, e.g., a PSFCH with N bits of information and N>1. In another example, the report is one bit indicating whether the beam is good (e.g., valid) or bad (e.g., invalid). In yet another example, the report is N bits, where N is a small number and N PSFCHs are used.

[0211] d. If the UE is within network coverage, the report may be sent to the network (or gNB) 130 using UCI on PUCCH or PUSCH, and / or the report may be sent to the network (or gNB) 130 using MAC CE on the Uu interface.

[0212] According to an embodiment of the present disclosure, a beam used for communication between a first UE and a second UE may be identified.

[0213] In one example for the first UE, the same beam is used to send PSSCH / PSCCH and PSFCH from the first UE to the second UE. In another example for the first UE, the same beam is used to receive PSSCH / PSCCH and PSFCH from the second UE at the first UE. In another example for the first UE, different beams are used to send PSSCH / PSCCH and PSFCH from the first UE to the second UE. In yet another example for the first UE, different beams are used to receive PSSCH / PSCCH and PSFCH from the second UE at the first UE. In yet another example for the first UE, different beams are used to send PSSCH and PSCCH from the first UE to the second UE. In yet another example for the first UE, different beams are used to send PSSCH and PSCCH from the first UE to the second UE. In yet another example for the first UE, different beams are used to receive PSSCH and PSCCH from the second UE at the first UE. The roles of the first UE and the second UE may be interchanged.

[0214] In one example, if the transmit beam to the second UE is known, the UE can have a beam correspondence between the transmit beam and the receive beam without beam scanning. The receive beam from the second UE is also known without beam scanning.

[0215] In another example, if the receive beam from the second UE is known, the UE can have a beam correspondence between the transmit beam and the receive beam without beam scanning. In the absence of beam scanning, the transmit beam to the second UE is also known.

[0216] In yet another example, the UE performs beam scanning to determine a receive beam from a second UE regardless of whether it knows a transmit beam to the second UE.

[0217] In yet another example, the UE performs beam scanning to determine a transmit beam to a second UE regardless of whether it knows a receive beam from the second UE.

[0218] According to an embodiment of the present disclosure, the DCR may be, for example, a message for performing link establishment sent on a PSSCH / PSCCH.

[0219] Fig. 9 An example of initial beam acquisition 900 according to an embodiment of the present disclosure is shown. For example, acquisition 900 may be performed by Figure 1 This example is for illustration only, and other embodiments may be used without departing from the scope of the present disclosure.

[0220] The DCR includes target user information. The DCR initiating unicast layer 2 link establishment is sent to UE-B via PC5 unicast transmission. When the DCR includes target user information:

[0221] a) UE-A sends a DCR message on multiple UE-A transmit beams (e.g., multiple UE-A spatial domain transmission filters), e.g., transmit beam scanning.

[0222] b) UE-B attempts to receive DCR messages sent on multiple UE-A transmit beams (e.g., UE-A spatial domain transmission filters), and determines a DCR message (e.g., a DCR message corresponding to a preferred UE-A transmit beam (e.g., UE-A spatial domain transmission filter)). In one example, UE-B may perform receive beam scanning to find a preferred receive beam (spatial domain receive filter) at UE-B. In this case, UE-A may repeatedly transmit on the same transmit beam (spatial domain transmission filter) from UE-A.

[0223] c) UE-B sends a response corresponding to the determined DCR message back to UE-A, which indicates the preferred transmit beam (spatial domain transmission filter) from UE-A to UE-B. In one example, the response from UE-B is sent on one transmit beam (spatial domain transmission filter) from UE-B. In one example, UE-A can perform receive beam scanning for the response to find the preferred receive beam (spatial domain receive filter) at UE-A. In this case, UE-B can repeat the response transmission on the same transmit beam (spatial domain transmission filter) from UE-B.

[0224] d) In one example, the response from UE-B is transmitted to UE-A on multiple transmit beams (spatial domain transmission filters) from UE-B. In one example, UE-A may perform receive beam scanning for the response to find the preferred receive beam (spatial domain receive filter) at UE-A. In this case, UE-B may repeat the response transmission on the same transmit beam (spatial domain transmission filter) from UE-B. In another example, UE-A may indicate to UE-B the preferred transmit beam (spatial domain transmission filter) from UE-B to UE-A.

[0225] Fig.10 An example of an implementation 1000 for linking a time slot index to a transmission beam according to an embodiment of the present disclosure is shown. For example, the implementation 1000 may be composed of Figure 1 UE 111 utilizes. This example is for illustration only, and other embodiments may be used without departing from the scope of the present disclosure.

[0226] In one example, the slot index determines or is linked to the UE-A transmit beam (e.g., the UE-A spatial domain transmit filter).

[0227] In another example, the slot index is a physical slot index.

[0228] In yet another example, the time slot index is a logical time slot index within a resource pool.

[0229] In yet another example, if there are N UE-A transmit beams (e.g., UE-A spatial domain transmission filters) 0, 1, ..., N-1, the DCR transmitted in the time slot with index m is transmitted on beam (e.g., spatial domain transmission filter) n, such that m%N=n. % is a modulo operator that determines the remainder after m is divided by N.

[0230] In yet another example, if the initial transmission of the DCR message is in time slot m 0 In time slot m 1 The DCR message is retransmitted so that m 0 %N=m 1 % N. N may be pre-configured and / or configured or updated via RRC signaling from the network and / or RRC signaling on PC5 and / or MAC CE signaling and / or L1 control signaling.

[0231] In yet another example, N may be specified in the system specification. In one example, if N is not (pre)configured, a default value specified in the system specification is used. After the UE has scanned N transmit beams, the UE may cyclically repeat the beam scanning (eg, retransmit).

[0232] In another example, after one transmit beam scanning cycle across the N transmit antennas, the UE may increase its power by a step size. The step size may be preconfigured and / or configured or updated via RRC signaling from the network and / or RRC signaling on PC5 and / or MAC CE signaling and / or L1 control signaling.

[0233] In yet another example, the step size may be specified in the system specification. In yet another example, if the step size is not (pre)configured, a default value specified in the system specification is used. In one example, whether or not the UE increases its power by the step size after scanning, the N transmit antennas may be preconfigured and / or configured or updated by RRC signaling from the network and / or RRC signaling on PC5 and / or MAC CE signaling and / or L1 control signaling.

[0234] In yet another example, after a cycle of M transmit beam scanning across N transmit antennas, the UE may increase its power by a step size (e.g., after N×M transmissions). The step size and / or M may be pre-configured and / or configured or updated by RRC signaling from the network and / or RRC signaling on PC5 and / or MAC CE signaling and / or L1 control signaling. In one example, the step size and / or M may be specified in the system specification. In yet another example, if the step size and / or M is not (pre) configured, a default value specified in the system specification is used.

[0235] In yet another example, if the number of transmit beams T is less than N, the UE leaves some NT opportunities unused per beam scanning period.

[0236] In yet another example, if the number of transmit beams T is less than N, the UE may use more than one opportunity in each beam scanning cycle for transmitting a beam. For example, the choice of leaving some opportunities unused per beam scanning cycle or repeating the transmission of a beam in multiple opportunities per beam scanning cycle may be (pre)configured or left to the implementation of the UE.

[0237] In yet another example, if the number of transmit beams T is equal to N, the UE maps the transmit beams to the occasions of each beam scanning cycle.

[0238] In yet another example, if the number of transmit beams T is greater than N, the UE selects N transmit beams to map to the N opportunities in each beam scanning cycle. In a sub-example, the same N transmit beams are used in each beam scanning cycle. In a sub-example, different N transmit beams may be used in each beam scanning cycle.

[0239] Fig.11 An example of an implementation 1100 for linking a time slot index to a transmission beam according to an embodiment of the present disclosure is shown. For example, the implementation 1100 may be composed of Figure 1 This example is for illustration only, and other embodiments may be used without departing from the scope of the present disclosure.

[0240] In one example, if there are N UE-A transmit beams (e.g., UE-A spatial domain transmission filters) 0, 1, ..., N-1, then the DCR transmitted in the time slot with index m is transmitted on beam (e.g., spatial domain transmission filter) n such that % is OK Modulo operator for the remainder after division by N. Wherein, M is the number of time slots that the DCR message (i.e., link establishment message) can be repeated on the same beam. M can be pre-configured and / or configured or updated through RRC signaling from the network and / or RRC signaling on PC5 and / or MAC CE signaling and / or L1 control signaling.

[0241] In another example, M may be specified in the system specification. In yet another example, if M is not (pre-)configured, a default value specified in the system specification is used.

[0242] In yet another example, if the initial transmission of the DCR message is in time slot m 0 In time slot m 1 The DCR message is retransmitted so that m 0 %NM=m 1 % NM. The repetition of the DCR message in multiple time slots in the same UE-A transmit beam (e.g., UE spatial domain transmit filter) may be used for spatial domain receive filter scanning at the UE receiving the DCR message, i.e., for UE-B to refine its receive beam for transmissions from UE-A. N may be preconfigured and / or configured or updated by RRC signaling from the network and / or RRC signaling on PC5 and / or MAC CE signaling and / or L1 control signaling.

[0243] In yet another example, N may be specified in the system specification. In yet another example, if N is not (pre-)configured, a default value specified in the system specification is used. After the UE has swept N×M transmit beams, the UE may cyclically repeat the beam sweep (eg, retransmit).

[0244] In another example, after one transmit beam scanning cycle across N×M transmit antennas, the UE may increase its power by a step size. The step size may be preconfigured and / or configured or updated via RRC signaling from the network and / or RRC signaling on PC5 and / or MAC CE signaling and / or L1 control signaling.

[0245] In yet another example, the step size may be specified in the system specification. In yet another example, if the step size is not (pre)configured, a default value specified in the system specification is used.

[0246] In yet another example, regardless of whether the UE increases its power in steps after scanning, the N×M transmit antennas may be pre-configured and / or configured or updated via RRC signaling from the network and / or RRC signaling on PC5 and / or MAC CE signaling and / or L1 control signaling.

[0247] In yet another example, after a cycle of K transmit beam scanning across N×M transmit antennas, the UE may increase its power by a step size (e.g., after N×M×K transmissions). The step size and / or K may be pre-configured and / or configured or updated via RRC signaling from the network and / or RRC signaling on PC5 and / or MAC CE signaling and / or L1 control signaling.

[0248] In yet another example, the step size and / or K may be specified in the system specification. In yet another example, if the step size and / or K are not (pre-)configured, a default value specified in the system specification is used.

[0249] In yet another example, if the number of transmit beams T is less than N, the UE leaves some (NT)×M opportunities unused per beam scanning cycle. In one example, if the number of transmit beams T is less than N, the UE may use more than M opportunities per beam scanning cycle for transmitting beams. For example, the choice of leaving some opportunities unused per beam scanning cycle or repeating the transmission beam in multiple opportunities per beam scanning cycle may be (pre)configured or left to the implementation of the UE.

[0250] In yet another example, if the number of transmit beams T is equal to N, the UE maps the transmit beams to M opportunities per beam scanning cycle.

[0251] In yet another example, if the number of transmit beams T is greater than N, the UE selects N transmit beams to map to N×M opportunities per beam scanning cycle.

[0252] In one sub-example, the same N transmit beams are used in each beam scanning cycle. In one sub-example, different N transmit beams may be used in each beam scanning cycle.

[0253] Fig.12 An example of an implementation 1200 for linking a slot index to a transmission beam according to an embodiment of the present disclosure is shown. For example, the implementation 1200 may be composed of Figure 1 This example is for illustration only, and other embodiments may be used without departing from the scope of the present disclosure.

[0254] In one example, if there are N UE-A transmit beams (e.g., UE-A spatial domain transmission filters) 0, 1, ..., N-1, then the DCR transmitted in the time slot with index m is transmitted on beam (e.g., spatial domain transmission filter) n such that

[0255] (mr)%R=0 and % is OK Modulo operator for the remainder after division by N. R may be pre-configured and / or configured or updated by RRC signaling from the network and / or RRC signaling on PC5 and / or MAC CE signaling and / or L1 control signaling.

[0256] In another example, R may be specified in the system specification. In yet another example, if R is not (pre)configured, a default value specified in the system specification is used. r may be preconfigured and / or configured or updated via RRC signaling from the network and / or RRC signaling on PC5 and / or MAC CE signaling and / or L1 control signaling.

[0257] In yet another example, r may be specified in the system specification, for example, r = 0. In yet another example, if r is not (pre-)configured, a default value specified in the system specification is used, for example, r = 0.

[0258] In yet another example, if the initial transmission of the DCR message is in time slot m 0 In time slot m 1 The DCR message is retransmitted so that m 0 %NR=m 1 %NR. N may be pre-configured and / or configured or updated via RRC signaling from the network and / or RRC signaling on PC5 and / or MAC CE signaling and / or L1 control signaling.

[0259] In yet another example, N may be specified in the system specification. In yet another example, if N is not (pre)configured, a default value specified in the system specification is used. After the UE has scanned N×R transmit beams, the UE may cyclically repeat the beam scanning (eg, retransmit).

[0260] In another example, after one transmit beam scanning cycle across the N transmit antennas, the UE may increase its power by a step size. The step size may be preconfigured and / or configured or updated via RRC signaling from the network and / or RRC signaling on PC5 and / or MAC CE signaling and / or L1 control signaling.

[0261] In yet another example, the step size may be specified in the system specification. In yet another example, if the step size is not (pre)configured, a default value specified in the system specification is used.

[0262] In yet another example, whether or not the UE increases its power in steps after scanning, the N transmit antennas may be pre-configured and / or configured or updated via RRC signaling from the network and / or RRC signaling on PC5 and / or MAC CE signaling and / or L1 control signaling.

[0263] In yet another example, after K transmit beam scanning cycles across N transmit antennas, the UE may increase its power by a step size (i.e., after N×K transmissions). The step size and / or K may be pre-configured and / or configured or updated via RRC signaling from the network and / or RRC signaling on PC5 and / or MAC CE signaling and / or L1 control signaling.

[0264] In yet another example, the step size and / or K may be specified in the system specification. In yet another example, if the step size and / or K are not (pre-)configured, a default value specified in the system specification is used.

[0265] In yet another example, if the number of transmit beams T is less than N, the UE leaves some NT opportunities unused per beam scanning period.

[0266] In yet another example, if the number of transmit beams T is less than N, the UE may use more than one opportunity in each beam scanning cycle for transmitting a beam. For example, the choice of leaving some opportunities unused per beam scanning cycle or repeating the transmission of a beam in multiple opportunities per beam scanning cycle may be (pre)configured or left to the implementation of the UE.

[0267] In yet another example, if the number of transmit beams T is equal to N, the UE maps the transmit beams to the opportunities of each beam scanning cycle. In yet another example, if the number of transmit beams T is greater than N, the UE selects N transmit beams to map to the N opportunities of each beam scanning cycle.

[0268] In one sub-example, the same N transmit beams are used in each beam scanning cycle. In one sub-example, different N transmit beams may be used in each beam scanning cycle.

[0269] Fig.13 1 shows an example of an S-SSB 1300 according to an embodiment of the present disclosure. For example, the S-SSB 1300 may be composed of Figure 1 Any one of UEs 111-116 utilizes. This example is for illustration only, and other embodiments may be used without departing from the scope of the present disclosure.

[0270] In one example, the nearest S-SSB transmission determines or is linked to the UE-A transmit beam (e.g., UE-A spatial domain transmit filter). The SL UE receives or transmits the SL primary synchronization signal (S-PSS), SL secondary synchronization signal (S-SSS), and physical SL broadcast channel (PSBCH). The UE assumes that the reception timings of PSBCH, S-PSS, and S-SSS are in consecutive symbols and form an S-SS / PSBCH block (S-SSB). The UE is provided with a period of 16 frames via the higher layer parameter sl-NumSSB-WithinPeriod. The number of S-SSBs. sl-NumSSB-WithinPeriod The allowed values ​​depend on the frequency range and the subcarrier spacing (SCS):

[0271] a) For FR1 and SCS = 15kHz,

[0272] b) For FR1 and SCS = 30kHz,

[0273] c) For FR1 and SCS = 60kHz,

[0274] d) For FR2 and SCS = 60kHz,

[0275] e) For FR2 and SCS = 120kHz,

[0276] The transmission of S-SSB of this period has a periodicity of 16 frames. The index of the time slot of the SSB transmission is determined by the following formula:

[0277]

[0278] in,

[0279] a) Slot index 0 corresponds to the first slot of a frame with (SFN mod 16)=0 or (DFN mod 16)=0.

[0280] b) Given by the higher layer parameter sl-TimeOffsetSSB, which is in the range {0, 1, ..., 1279}.

[0281] c) Given by a higher layer parameter in the range: {0, 1, ..., 639}

[0282] In one example, the DCR transmission between S-SSB 0 and S-SSB 1 is associated with or linked to a first UE-A TX beam (e.g., a first UE-A spatial domain transmission filter), and the DCR transmission between S-SSB 1 and S-SSB 2 is associated with or linked to a second UE-ATX beam (e.g., a second UE-A spatial domain transmission filter)… and The DCR transmission between UE-A TX beam (e.g., UE-A spatial domain transmission filter) is associated or linked to the UE-ATX beam (for example, UE-A spatial domain transmission filter), S-SSB The DCR transmission after and before S-SSB 0 in the next 16-frame period is the same as the first UE-ATx beam (e.g. UE-A spatial domain transmission filter) is associated or linked to the UE-A Tx beam (e.g. UE-A spatial domain transmission filter).

[0283] In one example, the DCR transmission between S-SSB 0 and S-SSB 1 is associated with or linked to a first UE-A TX beam (e.g., a first UE-A spatial domain transmission filter), and the DCR transmission between S-SSB 1 and S-SSB 2 is associated with or linked to a second UE-ATX beam (e.g., a second UE-A spatial domain transmission filter)… and The DCR transmission between UE-A TX beam (e.g., UE-A spatial domain transmission filter) is associated or linked to the UE-ATX beam (for example, UE-A spatial domain transmission filter), After that and before the end of the next 16-frame period, the DCR transmission is the same as the first UE-A Tx beam (e.g. UE-A spatial domain transmission filter) is associated or linked to the UE-ATx beam (e.g. UE-A spatial domain transmission filter).

[0284] In one example, the DCR transmission between S-SSB 0 and S-SSB 1 is associated with or linked to a first UE-A TX beam (e.g., a first UE-A spatial domain transmission filter), and the DCR transmission between S-SSB 1 and S-SSB 2 is associated with or linked to a second UE-ATX beam (e.g., a second UE-A spatial domain transmission filter)… and The DCR transmission between UE-A TX beam (e.g., UE-A spatial domain transmission filter) is associated or linked to the UE-A TX beam (e.g., UE-A spatial domain transmission filter), After and from rise The DCR transmission of the first time slot is UE-ATx beam (e.g. UE-A spatial domain transmission filter) is associated or linked to the UE-ATx beam (e.g. UE-A spatial domain transmission filter).

[0285] In one example, a DCR transmission after S-SSB 0 and before S-SSB 1 and no more than K time slots starting from S-SSB 0 is associated with or linked to a first UE-A Tx beam (e.g., a first UE-A spatial domain transmission filter), a DCR transmission after S-SSB 1 and before S-SSB 2 and no more than K time slots starting from S-SSB 1 is associated with or linked to a second UE-ATx beam (e.g., a second UE-A spatial domain transmission filter), ..., Afterwards and Before and since Start DCR transmission of no more than K time slots with the first UE-A Tx beam (e.g. UE-A spatial domain transmission filter) is associated or linked to the UE-ATx beam (e.g. UE-A spatial domain transmission filter), in After and before S-SSB 0 of the next 16-frame interval and from Start DCR transmission of no more than K time slots with the first UE-A Tx beam (e.g. UE-A spatial domain transmission filter) is associated or linked to the UE-ATx beam (e.g. UE-A spatial domain transmission filter).

[0286] In one example, K is in units of logical time slots in a resource pool. In one example, K is in units of physical time slots. K can be pre-configured and / or configured or updated by RRC signaling from the network and / or RRC signaling on PC5 and / or MAC CE signaling and / or L1 control signaling. In one example, K can be specified in the system specification, for example, K=1 or K=2. In one example, if K is not (pre) configured, a default value specified in the system specification is used, for example, K=1 or K=2. In one example, K is the same for all S-SSBs. In one example, different Ks can be configured for each S-SSB or some of the S-SSBs.

[0287] In one example, a DCR transmission after S-SSB 0 and before S-SSB 1 and no more than K time slots from S-SSB 0 is associated with or linked to a first UE-ATx beam (e.g., a first UE-A spatial domain transmission filter), a DCR transmission after S-SSB 1 and before S-SSB 2 and no more than K time slots from S-SSB 1 is associated with or linked to a second UE-ATx beam (e.g., a second UE-A spatial domain transmission filter), ..., Afterwards and Before and since Start DCR transmission of no more than K time slots with the first UE-ATx beam (e.g. UE-A spatial domain transmission filter) is associated or linked to the UE-ATx beam (e.g. UE-A spatial domain transmission filter), in After and before the end of the 16-frame interval and from Start DCR transmission of no more than K time slots with the first UE-ATx beam (e.g. UE-A spatial domain transmission filter) is associated or linked to the UE-ATx beam (e.g. UE-A spatial domain transmission filter).

[0288] In one example, K is in units of logical time slots in a resource pool. In one example, K is in units of physical time slots. K can be pre-configured and / or configured or updated through RRC signaling from the network and / or RRC signaling on PC5 and / or MAC CE signaling and / or L1 control signaling.

[0289] In one example, K may be specified in the system specification, e.g., K=1 or K=2. In one example, if K is not (pre)configured, a default value specified in the system specification is used, e.g., K=1 or K=2. In one example, K is the same for all S-SSBs. In one example, different Ks may be configured for each S-SSB or for some S-SSBs.

[0290] In one example, a DCR transmission after S-SSB 0 and no more than K time slots from S-SSB 0 is associated with or linked to a first UE-ATx beam (e.g., a first UE-A spatial domain transmission filter), a DCR transmission after S-SSB 1 and no more than K time slots from S-SSB 1 is associated with or linked to a second UE-A Tx beam (e.g., a second UE-A spatial domain transmission filter), ..., Afterwards and from Start DCR transmission of no more than K time slots with the first UE-A Tx beam (e.g. UE-A spatial domain transmission filter) is associated or linked to the UE-A Tx beam (e.g. UE-A spatial domain transmission filter), in Afterwards and from Start DCR transmission of no more than K time slots with the first UE-A Tx beam (e.g. UE-A spatial domain transmission filter) is associated or linked to the UE-A Tx beam (e.g. UE-A spatial domain transmission filter).

[0291] In one example, K is in units of logical time slots in a resource pool. In one example, K is in units of physical time slots. K can be pre-configured and / or configured or updated through RRC signaling from the network and / or RRC signaling on PC5 and / or MAC CE signaling and / or L1 control signaling.

[0292] In one example, K may be specified in the system specification, for example, K=1 or K=2. In one example, if K is not (pre-)configured, a default value specified in the system specification is used, for example, K=1 or K=2.

[0293] In one example, K is the same for all S-SSBs. In one example, different Ks may be configured for each S-SSB or for some S-SSBs.

[0294] In one example, a parameter (value) is included in the DCR, wherein the parameter (value) determines or is linked to the UE-A transmit beam (e.g., UE-A spatial domain transmission filter). In one example, the parameter (value) may be a UE-A transmit beam (e.g., UE-A spatial domain transmission filter) index.

[0295] In one example, the parameter (value) is a field in the first stage SCI in the PSCCH channel associated with the DCR. In one example, the parameter (value) is a field in the second stage SCI in the PSSCH channel associated with the DCR. In one example, the parameter (value) is a field in the SL shared channel (SL-SCH) in the PSCCH channel associated with the DCR. In one example, the parameter (value) is a field in the MAC CE associated with the DCR.

[0296] In one example, the DCR includes the SL CSI-RS. In one example, the SL CSI-RS may include and / or indicate the UE-ID. In one example, the SL CSI-RS may include and / or indicate the beam ID.

[0297] In one example, the sequence of SL CSI-RS resources is generated according to:

[0298]

[0299] Where m = 0, 1, ...

[0300] The pseudo-random sequence c(n) is a Gold sequence of length 31, defined as

[0301] c(n)=(x 1 (n+N c )+x 2 (n+N c ))mod 2

[0302] in,

[0303] N c =1600

[0304] x 1 (n+31)=(x 1 (n+3)+x 1 (n))mod 2

[0305] x 1 (n+31)=(x 2(n+3)+x 2 (n+2)+x 2 (n+1)+x 2 (n))mod 2

[0306] The first m sequence is initialized to: x 1 (0) = 1, and x 2 (n) = 0, for n = 1…30.

[0307] The second m-sequence is initialized to c init , where c init

[0308]

[0309] in,

[0310] a) is the number of symbols in a time slot.

[0311] b) is the timeslot number within the frame used for the subcarrier spacing configuration μ.

[0312] c) l is the OFDM symbol number in the time slot.

[0313] d) in, It is the decimal representation of the CRC of the first stage SL control information carried on the PSCCH.

[0314] In one example, the sequence of SL CSI-RS resources is the same for all UE-A transmit beams (UE-A spatial domain transmission filters). In one example, the sequence of SL CSI-RS resources depends on (is a function of) the UE-A transmit beam index (UE-A spatial domain transmission filter index). In one example, the sequence n ID Depends on UE-A transmit beam index (UE-A spatial domain transmit filter index).

[0315] In one example, equation c init Depends on UE-A transmit beam index (UE-A spatial domain transmit filter index).

[0316] In one example, the CSI-RS resource has a sequence as a function of the slot number and symbol number within a frame. In a variant example, the slot number is a logical slot number. In a variant example, the slot number is a slot number within a subframe. The slot number and / or symbol determines the beam (or spatial filter) ID based on a mapping between the slot / symbol index and the beam (or spatial filter) ID.

[0317] In one example, a DCR for a first UE (e.g., UE-A) to a second UE (e.g., UE-B) does not implicitly or explicitly indicate to UE-B the UE-A transmit beam index (UE-A spatial domain transmission filter). The DCR from UE-A is transmitted on multiple beams. A response to a particular transmission instance of the DCR allows UE-A to infer (e.g., based on timing) the UE-A transmit beam index (UE-A spatial domain transmission filter) for subsequent transmissions from UE-A to UE-B based on the transmission instance of the DCR to which UE-A received a response from UE-B.

[0318] In another example, a response to the DCR sent from UE-B to UE-A includes a signal quality indicator (e.g., SL reference signal received power (RSRP) or SL signal to interference and noise ratio (SINR) as measured by UE-B). In order to determine the UE-A transmit beam index (UE-A spatial domain transmission filter), UE-A may select a transmission instance with the best (e.g., maximum) signal quality indicator (e.g., SL RSRP or SL SINR). Alternatively, UE-A may select any transmission instance with a SL RSRP that exceeds a SL RSRP threshold or a SL SINR threshold. The SL RSRP threshold or SL SINR threshold may be pre-configured, and / or configured or updated, via RRC signaling from the network and / or RRC signaling on PC5 and / or MAC CE signaling and / or L1 control signaling. In one example, if the SL RSRP threshold or SL SINR threshold is not (pre) configured, a default value specified in the system specification is used.

[0319] In one example, the SL RSRP threshold or the SL SINR threshold depends on the priority of the corresponding DCR message. In one example, the SL RSRP may be based on the PSCCH DMRS RSRP or the PSSCH DMRS RSRP or the SL CSI-RS RSRP. In one example, the SL SINR may be based on the PSCCH DMRS SINR or the PSSCH DMRS SINR or the SL CSI-RS SINR.

[0320] In another example, a response to the DCR sent from UE-B to UE-A includes one or more corresponding resources for the DCR from UE-A, such as a starting (or ending) time resource (e.g., time slot and / or symbol - this can be absolute or relative to the response) and / or a starting (or ending) frequency resource (e.g., subchannel and / or PRB and / or subcarrier - this can be absolute or relative to the response). In another example, a response to the DCR sent from UE-B to UE-A includes a reference (e.g., an index) to the DCR from UE-A.

[0321] In one example, UE-B receives or attempts to receive a DCR message sent on multiple UE-A transmit beams (e.g., UE-A spatial domain transmission filters). UE-B may check whether its target user information (e.g., layer 2 destination ID) is included in the DCR message. Therefore, UE-B may follow one or more of the following:

[0322] a) In one example, if the DCR is successfully decoded, UE-B sends a response corresponding to the successfully decoded DCR back to UE-A.

[0323] b) In one example, if the DCR is successfully decoded and the SL RSRP of the DCR exceeds the SL RSRP threshold or the SL SINR of the DCR exceeds the SL SINR threshold, UE-B sends back a response corresponding to the DCR exceeding the SL RSRP threshold or the SL SINR threshold to UE-A. The SL RSRP or SL SINR can be determined based on the PSCCH DMRS or based on the PSSCH DMRS or based on the SLCSI-RS. The SL RSRP threshold or the SL SINR threshold can be pre-configured, and / or configured or updated via RRC signaling from the network and / or RRC signaling on PC5 and / or MAC CE signaling and / or L1 control signaling. In one example, if the SL RSRP threshold or the SL SINR threshold is not (pre) configured, the default value specified in the system specification is used. In one example, the SL RSRP threshold or the SL SINR threshold depends on the priority of the corresponding DCR message.

[0324] c) In one example, if multiple DCR messages are successfully decoded, UE-B determines the DCR message with the maximum SL RSRP or SL SINR. SL RSRP or SL SINR can be determined based on PSCCH DMRS or based on PSSCH DMRS or based on SLCSI-RS. UE-B sends a response corresponding to the determined DCR back to UE-A. In another example, a window can be (pre) configured during which UE-B attempts to receive a DCR message. In one example, the window starts in the time slot of the first successfully decoded DCR (or in the next time slot) and ends after T time slots, where T can be in units of logical time slots in the resource pool. In another example, T can be in units of physical time slots. In one example, T can be pre-configured and / or configured or updated by RRC signaling from the network and / or RRC signaling on PC5 and / or MAC CE signaling and / or L1 control signaling. In one example, T can be specified in the system specification. In one example, if T is not (pre) configured, a default value specified in the system specification is used.

[0325] d) In one example, if multiple DCR messages are successfully decoded and the SL RSRP of the DCR exceeds the SL RSRP threshold or the SL SINR of the DCR exceeds the SL SINR threshold, UE-B determines the DCR message with the maximum SL RSRP or SL SINR. UE-B sends a response corresponding to the determined DCR message back to UE-A. SL RSRP or SL SINR can be determined based on PSCCH DMRS or based on PSSCH DMRS or based on SL CSI-RS. The SL RSRP threshold or SL SINR threshold can be pre-configured and / or configured or updated by RRC signaling from the network and / or RRC signaling on PC5 and / or MAC CE signaling and / or L1 control signaling. In one example, if the SL RSRP threshold or SL SINR threshold is not (pre) configured, the default value specified in the system specification is used. In one example, the SL RSRP threshold or SL SINR threshold depends on the priority of the corresponding DCR message. In another example, a window can be (pre) configured during which UE-B attempts to receive a DCR message. In one example, the window starts in the time slot of the first successfully decoded DCR (or in the next time slot) and ends after T time slots. In one example, T can be in units of logical time slots in the resource pool. In another example, T can be in units of physical time slots. In one example, T can be pre-configured and / or configured or updated by RRC signaling from the network and / or RRC signaling on PC5 and / or MAC CE signaling and / or L1 control signaling. In one example, T can be specified in the system specification. In one example, if T is not (pre) configured, a default value specified in the system specification is used.

[0326] e) In one example, UE-B receives or attempts to receive DCRs corresponding to all transmit beams from UE-A before determining a DCR message to respond to. For example, within a (pre)configured window as described herein. In another example, the link establishment messages (e.g., DCRs) may be those sent in one transmit beam scan as described herein.

[0327] f) In one example, once UE-B successfully decodes the DCR message, UE-B may send a response corresponding to the successfully decoded DCR back to UE-A. In a variation of this example, before UE-B sends the response back to UE-A, it may depend on the implementation of UE-B whether to wait for decoding of other DCR messages (e.g., within a (pre)configured window as described herein).

[0328] g) In one example, once UE-B successfully decodes the DCR message and the corresponding SL RSRP or SL SINR of the DCR exceeds the SL RSRP threshold or SL SINR threshold, UE-B sends back a response to UE-A corresponding to the DCR that exceeds the SL RSRP threshold or SL SINR threshold. The SL RSRP or SL SINR can be determined based on the PSCCH DMRS or based on the PSSCH DMRS or based on the SL CSI-RS. The SL RSRP threshold or SL SINR threshold can be pre-configured and / or configured or updated by RRC signaling from the network and / or RRC signaling on PC5 and / or MAC CE signaling and / or L1 control signaling. In one example, if the SL RSRP threshold or SL SINR threshold is not (pre) configured, the default value specified in the system specification is used. In one example, the SLRSRP threshold or SL SINR threshold depends on the priority of the corresponding DCR message. In a variation of this example, before UE-B sends a response back to UE-A, it may depend on whether the implementation of UE-B waits for decoding other DCR messages. In one example, if UE-B waits, the decoded DCR may be within a (pre-)configured window as described herein.

[0329] h) In one example, if there is no DCR message with a SL RSRP exceeding the SL RSRP threshold at UE-B or a SL SINR exceeding the SLSINR threshold, UE-B receives or attempts to receive DCRs corresponding to all transmit beams from UE-A before determining the DCR message to respond to. In one example, the decoded DCR may be within a (pre)configured window as described herein. In another example, the link establishment messages (e.g., DCRs) may be those sent in a transmit beam scan as described herein. UE-B determines the DCR message with the maximum SL RSRP or SL SINR. The SL RSRP or SL SINR may be determined based on the PSCCH DMRS or based on the PSSCH DMRS or based on the SL CSI-RS. The SL RSRP threshold or SL SINR threshold may be preconfigured and / or configured or updated by RRC signaling from the network and / or RRC signaling on PC5 and / or MAC CE signaling and / or L1 control signaling. In one example, if there is no (pre)configured SL RSRP threshold or SL SINR threshold, the default value specified in the system specification is used. In one example, the SL RSRP threshold or the SL SINR threshold depends on the priority of the corresponding DCR message.

[0330] i) In one example, UE-A repeats the DCR message on the same transmit beam (spatial domain transmission filter), and UE-B uses a different receive beam (spatial domain reception filter) to attempt to receive the repeated DCR to discover the best receiver beam (spatial domain reception filter) to use (at UE-B). In one example, the resource pool can be (pre)configured whether repetition is turned on or off. Repetition can be preconfigured and / or configured or updated by RRC signaling from the network and / or RRC signaling on PC5 and / or MAC CE signaling and / or L1 control signaling. In one example, if repetition is not (pre)configured, the default value specified in the system specification is used. When repetition is turned on, UE-B can assume that the DCR message is repeated using the same transmit beam (spatial domain transmission filter) as UE-A. When repetition is turned off, UE-B cannot assume that the DCR message is repeated using the same transmit beam (spatial domain transmission filter) as UE-A. When repetition is turned on, the resource pool may be (pre)configured with a repetition count M, where M is the number of DCR transmissions on the same transmit beam (spatial domain transmission filter) from UE-A. M may be pre-configured and / or configured or updated via RRC signaling from the network and / or RRC signaling on PC5 and / or MAC CE signaling and / or L1 control signaling. In one example, if M is not (pre)configured, a default value specified in the system specification is used.

[0331] Fig.14 An example of transmit and receive beam scanning 1400 according to an embodiment of the present disclosure is shown. For example, any of UEs 111-116 may perform SL communication using beam scanning 1400. This example is for illustration only, and other embodiments may be used without departing from the scope of the present disclosure.

[0332] In one example, after a UE (e.g., UE-B) determines a corresponding transmit beam (or spatial domain transmission filter) and DCR from UE-A according to one or more examples described herein, UE-B sends a response, signal, or message to UE-A, where the response, signal, or message indicates the transmit beam (or spatial domain transmission filter) from UE-A.

[0333] In one example, the response is a PSFCH transmission corresponding to the DCR of the transmit beam (or spatial domain transmission filter) from UE-A. There is a relationship between the DCR (e.g., transmitted on the PSCCH / PSSCH) and the corresponding PSFCH resource. By receiving the PSFCH, UE-A will be able to determine the corresponding PSCCH / PSSCH and the associated transmit beam (spatial domain transmission filter) of the DCR. This can be the spatial domain filter that UE-A uses for subsequent transmissions to UE-B.

[0334] In another example, the PSFCH response includes a positive acknowledgement. In another example, the PSFCH response includes a negative acknowledgement. The retransmission of the DCR uses the transmit beam (spatial domain transmit filter) of the negatively acknowledged DCR.

[0335] In one example, UE-A receives multiple PSFCH transmissions in response to DCR messages sent on multiple transmit beams (spatial domain transmission filters).UE-A may select a transmit beam (spatial domain transmission filter) corresponding to one of the DCRs having the received PSFCH.

[0336] In one example, UE-A may select a transmit beam (spatial domain transmission filter) corresponding to the DCR associated with the strongest received PSFCH. In one example, UE-A may select a transmit beam (spatial domain transmission filter) corresponding to the DCR associated with the PSFCH including a positive acknowledgment. In one example, UE-A may select a transmit beam (spatial domain transmission filter) corresponding to the DCR associated with the strongest received PSFCH including a positive acknowledgment.

[0337] In one example, if UE-B receives multiple DCRs that are successfully decoded, UE-B only sends a PSFCH with a positive acknowledgement for one of the successfully decoded DCRs. For example, the DCR associated with the preferred transmit beam (or spatial domain transmission filter) can be according to one or more examples described herein. In one example, if UE-B receives multiple DCRs that are successfully decoded, UE-B can send a PSFCH with a positive acknowledgement for the successfully decoded DCR or a subset of the successfully decoded DCRs.

[0338] In one example, the response is a PSCCH transmission corresponding to the DCR of the transmit beam (or spatial domain transmit filter) from UE-A. There may be a fixed relationship between DCR and PSCCH transmission.

[0339] For example, a DCR (eg, associated with a preferred transmit beam (or spatial domain transmit filter) from UE-A) and a fixed time offset between PSCCH transmissions may be determined according to one or more examples described herein.

[0340] In another example, there is a mapping between resources (eg, associated with a preferred transmit beam (or spatial domain transmit filter) from UE-A) and PSCCH transmissions for a DCR determined according to one or more examples described herein.

[0341] In another example, a DCR determined according to one or more examples described herein (eg, associated with a preferred transmit beam (or spatial domain transmit filter) from UE-A) indicates resources for a corresponding PSCCH transmission.

[0342] In one example, the time slot of the link establishment message (e.g., DCR) - time slot n - the time slot of the determination response message (e.g., PSCCH) - time slot m - for example, m = n + D, m ≥ n + D, m > n + D, where D can be pre-configured and / or configured or updated via RRC signaling from the network and / or RRC signaling on PC5 and / or MAC CE signaling and / or L1 control signaling.

[0343] In one example, D may be specified in the system specification. In one example, if D is not (pre)configured, a default value specified in the system specification is used.

[0344] In one example, m and / or n and / or D may be in a logical time slot of a resource pool. In one example, m and / or n and / or D may be in a logical time slot that may be in a resource pool. In one example, m and / or n and / or D may be in a physical time slot or physical time.

[0345] In one example, UE-A receives multiple PSCCH transmissions in response to DCR messages sent on multiple transmit beams (spatial domain transmission filters).UE-A may select a transmit beam (spatial domain transmission filter) corresponding to one of the DCRs having the received PSCCH transmissions.

[0346] In one example, UE-A may select a transmit beam (spatial domain transmit filter) that corresponds to the DCR associated with the strongest received PSCCH transmission.

[0347] In one example, if UE-B receives multiple DCRs that are successfully decoded, UE-B only sends a PSCCH transmission for one of the successfully decoded DCRs.For example, the DCR associated with the preferred transmit beam (or spatial domain transmit filter) can be according to one or more examples described herein.

[0348] In one example, if UE-B receives multiple DCRs that are successfully decoded, UE-B may send a PSCCH transmission for the successfully decoded DCRs or a subset of the successfully decoded DCRs.

[0349] In one example, the PSCCH transmission includes a quality metric for the corresponding DCR. For example, the quality metric may be the SL RSRP (PSCCH RSRP or PSSCH RSRP or SL CSI-RS RSRP) of the DCR. In another example, the quality metric may be the SL SINR (PSCCH SINR or PSSCH SINR or SL CSI-RS SINR) of the DCR.

[0350] In another example, UE-A may determine a transmit beam (spatial domain transmit filter) for subsequent transmissions from UE-A based at least on the quality metric.

[0351] In one example, in response to one or more DCR transmissions (e.g., transmissions associated with multiple transmit beams (spatial domain transmission filters) from UE-A), UE-B transmits a PSCCH transmission. The PSCCH transmission includes an indication of a determined DCR according to one or more examples described herein, e.g., a DCR associated with a preferred transmit beam (or spatial domain transmission filter) from UE-A.

[0352] In one example, the PSCCH transmission is sent multiple times on different transmit beams (or spatial domain transmit filters) from UE-B for transmit beam scanning from UE-B.

[0353] In one example, the response is a PSCCH / PSSCH transmission corresponding to the DCR of the transmit beam (or spatial domain transmission filter) from UE-A. There may be a fixed relationship between the DCR and the PSCCH / PSSCH transmission, such as a fixed time offset between the DCR determined according to one or more examples described herein (e.g., associated with a preferred transmit beam (or spatial domain transmission filter) from UE-A) and the PSCCH / PSSCH transmission.

[0354] In another example, there is a mapping between resources used for determining a DCR (e.g., associated with a preferred transmit beam (or spatial domain transmit filter) from UE-A) according to one or more examples described herein and PSCCH / PSSCH transmissions.

[0355] In another example, a DCR determined according to one or more examples described herein (eg, associated with a preferred transmit beam (or spatial domain transmit filter) from UE-A) indicates resources used for corresponding PSCCH / PSSCH transmissions.

[0356] In one example, the time slot of the link establishment message (e.g., DCR) - time slot n - determines the time slot of the response message (e.g., PSCCH / PSCCH) - time slot m - for example, m=n+D, m≥n+D or m>n+D, where D can be pre-configured and / or configured or updated via RRC signaling from the network and / or RRC signaling on PC5 and / or MAC CE signaling and / or L1 control signaling.

[0357] In one example, D may be specified in the system specification. In one example, if D is not (pre)configured, a default value specified in the system specification is used.

[0358] In one example, m and / or n and / or D may be in a logical time slot of a resource pool. In one example, m and / or n and / or D may be in a logical time slot that may be in a resource pool. In one example, m and / or n and / or D may be in a physical time slot or physical time.

[0359] In one example, UE-A receives multiple PSCCH / PSSCH transmissions in response to DCR messages sent on multiple transmit beams (spatial domain transmission filters). UE-A may select a transmit beam (spatial domain transmission filter) corresponding to one of the DCRs having the received PSCCH / PSSCH transmissions.

[0360] In one example, UE-A may select a transmit beam (spatial domain transmit filter) corresponding to the DCR associated with the strongest received PSCCH / PSSCH transmission or the strongest SL CSI-RS associated with or included in the PSCCH / PSSCH.

[0361] In one example, if UE-B receives multiple DCRs that are successfully decoded, UE-B sends a PSCCH / PSSCH transmission only for one of the successfully decoded DCRs, such as a DCR associated with a preferred transmit beam (or spatial domain transmit filter) according to one or more examples described herein.

[0362] In one example, if UE-B receives multiple DCRs that are successfully decoded, UE-B may send a PSCCH / PSSCH transmission for the successfully decoded DCRs or a subset of the successfully decoded DCRs.

[0363] In one example, the PSCCH / PSSCH transmission includes a quality metric for the corresponding DCR. For example, the quality metric may be the SL RSRP of the DCR (PSCCH RSRP or PSSCH RSRP or SL CSI-RS RSRP). In another example, the quality metric may be the SL SINR of the DCR (PSCCH SINR or PSSCH SINR or SL CSI-RS SINR).

[0364] In another example, UE-A may determine a transmit beam (spatial domain transmit filter) from UE-A for subsequent transmission based at least on a quality metric. In one example, the quality metric may be in a first stage SCI (e.g., in a PSCCH). In another example, the quality metric may be in a second stage SCI (e.g., in a PSSCH). In another example, the quality metric may be in a SL shared channel (e.g., in a PSSCH). In another example, the quality metric may be in a MAC CE.

[0365] In one example, in response to one or more DCR transmissions (e.g., transmissions associated with multiple transmit beams (spatial domain transmission filters) from UE-A), UE-B transmits a PSCCH / PSSCH transmission. The PSCCH / PSSCH transmission includes an indication of a determined DCR according to one or more examples described herein, such as a DCR associated with a preferred transmit beam (or spatial domain transmission filter) from UE-A. In one example, the indication may be in a first stage SCI (e.g., in the PSCCH). In another example, the indication may be in a second stage SCI (e.g., in the PSSCH). In another example, the indication may be in a SL shared channel (e.g., in the PSSCH). In another example, the indication may be in a MAC CE.

[0366] In one example, PSCCH / PSSCH transmissions are sent multiple times on different transmit beams (or spatial domain transmit filters) from UE-B for transmit beam scanning from UE-B.

[0367] In one example, a response to a DCR transmitted from UE-A over a plurality of transmit beams (spatial domain transmission filters), indicating the determined DCR and its associated transmit beams (spatial domain transmission filters), is included in (or is part of) a security establishment procedure, e.g., Figure 7 Step 740.

[0368] In one example, UE-B may determine a transmit beam for a response message to UE-A based on beam correspondence or beam reciprocity between a transmit beam (or spatial domain transmit filter) of UE-B and a receive beam (or spatial domain receive filter) of UE-B, for example, a PSFCH according to one or more examples described herein and a security establishment procedure according to one or more examples described herein. A receive beam (or spatial domain receive filter) of UE-B for receiving a DCR (e.g., a DCR determined according to one or more examples described herein) determines a transmit beam (or spatial domain transmit filter) used by UE-B to send a response to UE-A.

[0369] In another example, a response message according to one or more examples described herein is repeated multiple times on the same transmit beam (spatial domain transmit filter) from UE-B to allow UE-A to perform RX beam scanning and discover the preferred RX beam (spatial domain receive filter) at UE-A.

[0370] In another example, UE-A determines its receive beam (spatial domain receive filter) based on beam correspondence (beam reciprocity) using UE-A's transmit beam (spatial domain receive filter) corresponding to DCR sent from UE-A.

[0371] For example, if UE-A sends a message in time slot n and expects to receive a response in time slot m, UE-A determines the RX beam of time slot m based on the beam correspondence with the TX beam used in time slot n.

[0372] In one example, a response message from UE-B (e.g., PSFCH, PSCCH and / or PSCCH / PSSCH according to one or more examples described herein and a security establishment procedure according to one or more examples described herein) is sent from UE-B on multiple transmit beams (spatial domain transmission filters). The transmissions in the multiple beams may be in different time and / or frequency and / or code (e.g., cyclic shift of PSFCH) resources. UE-A may determine a transmission from UE-B that corresponds to a transmit beam (e.g., spatial domain transmission filter) from UE-B that is preferred for subsequent transmissions from UE-B. UE-A may, for example, signal a preferred transmission to UE-B using one or more examples described herein, where the roles of UE-A and UE-B are switched. UE-A can determine the corresponding preferred transmit beam (e.g., spatial domain transmission filter) and preferred transmission from UE-B based on a quality metric (e.g., SL RSPR), where the SL RSRP can be based on PSCCH DMRS RSRP or PSSCH DMRS RSRP or SL CSI-RS RSRP or SL SINR, where the SL SINR can be based on PSCCH DMRS SINR or PSSCH DMRS SINR or SL CSI-RS SINR.

[0373] In another example, a response message according to one or more examples described herein is repeated multiple times on each transmit beam (spatial domain transmit filter) from UE-B (in addition to having multiple Tx beams) to allow UE-A to perform RX beam scanning and discover the preferred RX beam (spatial domain receive filter) at UE-A.

[0374] In another example, UE-A determines its receive beam (spatial domain receive filter) based on beam correspondence (beam reciprocity) using UE-A's transmit beam (spatial domain receive filter) corresponding to DCR sent from UE-A.

[0375] For example, if UE-A transmits a message in time slot n and expects to receive a response in time slot m, UE-A determines the Rx beam for time slot m based on the beam correspondence with the TX beam used in time slot n.

[0376] According to one or more examples described herein, when UE-B receives one or more link establishment messages from UE-A, an example of a response from UE-B may be:

[0377] a) In one example, each response from UE-B corresponds to one of the messages received from UE-A. In a sub-example, UE-B may send one message (e.g., if UE-B receives (e.g., successfully decodes) more than one link establishment message, UE-B may select one of them based on the aforementioned example and send a corresponding response). In a sub-example, UE-B may send multiple messages (e.g., if UE-B receives (e.g., successfully decodes) more than one link establishment message, UE-B may select some or all of them based on the aforementioned example and send a corresponding response for each message).

[0378] b) In one example, the response from UE-B corresponds to one or more messages received from UE-A. For example, a single response message may be sent for a link setup message (or a subset of received link setup messages) received at UE-B from UE-A. UE-B may select one, some, or all of the received link setup messages to include in a message sent to UE-A based on selection criteria according to one or more examples described herein.

[0379] c) In one example, the response from UE-B may be PSFCH and / or PSCCH and / or PSCCH / PSSCH (eg, second stage SCI and / or first stage SCI) and / or PSCCH / PSSCH (eg, MAC CE).

[0380] In one example, the DCR does not include target user information. The DCR for initiating unicast layer-2 link establishment is sent to multiple UEs via PC5 broadcast transmission. UEs interested in using the advertised V2X service type respond to the DCR.

[0381] Fig.15 An example of initial beam acquisition 1500 according to an embodiment of the present disclosure is shown. For example, acquisition 1500 may be performed by any one of UEs 111-116 for SL communication. This example is for illustration only, and other embodiments may be used without departing from the scope of the present disclosure.

[0382] UE-A sends a DCR message on multiple UE-A transmit beams (e.g., multiple UE-A spatial domain transmission filters), such as transmit beam scanning. UE-B attempts to receive the DCR message sent on multiple UE-A transmit beams (e.g., UE-A spatial domain transmission filters) and determines whether it is interested in the announced service type. If UE-B is interested in the announced service type, UE-B determines the DCR message (e.g., a DCR message corresponding to the preferred UE-A transmit beam (e.g., UE-A spatial domain transmission filter)).

[0383] In one example, UE-B may perform receive beam scanning to discover a preferred receive beam (spatial domain receive filter) at UE-B. In this case, UE-A may repeat transmissions on the same transmit beam (spatial domain transmit filter) from UE-A. UE-B sends a response corresponding to the determined DCR message back to UE-A, which indicates the preferred transmit beam (spatial domain transmit filter) from UE-A to UE-B.

[0384] In one example, the response from UE-B is transmitted on one transmit beam (spatial domain transmit filter) from UE-B.

[0385] In one example, UE-A may perform receive beam scanning for the response to discover a preferred receive beam (spatial domain receive filter) at UE-A. In this case, UE-B may repeat the response transmission on the same transmit beam (spatial domain transmit filter) from UE-B.

[0386] In one example, the response from UE-B is transmitted from UE-B to UE-A over multiple transmit beams (spatial domain transmission filters).

[0387] In one example, UE-A may perform receive beam scanning for the response to discover a preferred receive beam (spatial domain receive filter) at UE-A. In this case, UE-B may repeat the response transmission on the same transmit beam (spatial domain transmit filter) from UE-B.

[0388] In another example, UE-A may indicate to UE-B a preferred transmit beam (spatial domain transmission filter) from UE-B to UE-A.

[0389] There may be one or more UE-Bs that are interested in the announced service type. Therefore, UE-A may receive one or more responses from one or more UE-Bs. It is also possible that no UE is interested in the announced service type, or no UE receives the DCR message, in which case there may be no response returned to UE-A.

[0390] In one example, UE-A transmits a DCR message on multiple UE-A transmit beams (e.g., multiple UE-A spatial domain transmission filters), for example, UE-A performs transmit beam scanning.

[0391] Fig.16 1 shows an example of an S-SSB 1600 according to an embodiment of the present disclosure. For example, the S-SSB 1600 may be composed of Figure 1 This example is for illustration only, and other embodiments may be used without departing from the scope of the present disclosure.

[0392] In one example, the DCR transmission between S-SSB 0 and S-SSB 1 is associated with or linked to a first UE-A TX beam (e.g., a first UE-A spatial domain transmission filter), and the DCR transmission between S-SSB 1 and S-SSB 2 is associated with or linked to a second UE-A TX beam (e.g., a second UE-A spatial domain transmission filter)… and The DCR transmission between UE-A TX beam (e.g., UE-A spatial domain transmission filter) is associated or linked to the UE-ATX beam (for example, UE-A spatial domain transmission filter), The DCR transmission after and before S-SSB 0 in the next 16-frame period is the same as the first UE-ATx beam (e.g. UE-A spatial domain transmission filter) is associated or linked to the UE-ATx beam (e.g. UE-A spatial domain transmission filter).

[0393] In one example, the DCR transmission between S-SSB 0 and S-SSB 1 is associated with or linked to a first UE-ATX beam (e.g., a first UE-A spatial domain transmission filter), and the DCR transmission between S-SSB 1 and S-SSB 2 is associated with or linked to a second UE-ATX beam (e.g., a second UE-A spatial domain transmission filter)… and The DCR transmission between UE-ATX beam (for example, UE-A spatial domain transmission filter) is associated or linked to the UE-ATX beam (for example, UE-A spatial domain transmission filter), After that and before the end of the next 16-frame period, the DCR transmission is the same as the first UE-ATx beam (e.g. UE-A spatial domain transmission filter) is associated or linked to the UE-ATx beam (e.g. UE-A spatial domain transmission filter).

[0394] In one example, the DCR transmission between S-SSB 0 and S-SSB 1 is associated with or linked to a first UE-ATX beam (e.g., a first UE-A spatial domain transmission filter), and the DCR transmission between S-SSB 1 and S-SSB 2 is associated with or linked to a second UE-ATX beam (e.g., a second UE-A spatial domain transmission filter)… and The DCR transmission between UE-ATX beam (for example, UE-A spatial domain transmission filter) is associated or linked to the UE-ATX beam (for example, UE-A spatial domain transmission filter), After and from rise The DCR transmission of the first time slot is UE-ATx beam (e.g. UE-A spatial domain transmission filter) is associated or linked to the UE-ATx beam (e.g. UE-A spatial domain transmission filter).

[0395] In one example, a DCR transmission after S-SSB 0 and before S-SSB 1 and no more than K time slots from S-SSB 0 is associated with or linked to a first UE-ATx beam (e.g., a first UE-A spatial domain transmission filter), a DCR transmission after S-SSB 1 and before S-SSB 2 and no more than K time slots from S-SSB 1 is associated with or linked to a second UE-ATx beam (e.g., a second UE-A spatial domain transmission filter), ..., Afterwards and Before and since Start DCR transmission of no more than K time slots with the first UE-A Tx beam (e.g. UE-A spatial domain transmission filter) is associated or linked to the UE-A Tx beam (e.g. UE-A spatial domain transmission filter), in After and before S-SSB 0 of the next 16-frame interval and from Start DCR transmission of no more than K time slots with the first UE-ATx beam (e.g. UE-A spatial domain transmission filter) is associated or linked to the UE-ATx beam (e.g. UE-A spatial domain transmission filter).

[0396] In one example, K is in units of logical time slots in a resource pool. In one example, K is in units of physical time slots. K can be pre-configured and / or configured or updated through RRC signaling from the network and / or RRC signaling on PC5 and / or MAC CE signaling and / or L1 control signaling.

[0397] In one example, K may be specified in the system specification, e.g., K=1 or K=2. In one example, if K is not (pre)configured, a default value specified in the system specification is used, e.g., K=1 or K=2. In one example, K is the same for all S-SSBs. In one example, different Ks may be configured for each S-SSB or for some S-SSBs.

[0398] In one example, a DCR transmission after S-SSB 0 and before S-SSB 1 and no more than K time slots from S-SSB 0 is associated with or linked to a first UE-ATx beam (e.g., a first UE-A spatial domain transmission filter), a DCR transmission after S-SSB 1 and before S-SSB 2 and no more than K time slots from S-SSB 1 is associated with or linked to a second UE-ATx beam (e.g., a second UE-A spatial domain transmission filter), ..., Afterwards and Before and since Start DCR transmission of no more than K time slots with the first UE-ATx beam (e.g. UE-A spatial domain transmission filter) is associated or linked to the UE-ATx beam (e.g. UE-A spatial domain transmission filter), in After and before the end of the 16-frame interval and from Start DCR transmission of no more than K time slots with the first UE-A Tx beam (e.g. UE-A spatial domain transmission filter) is associated or linked to the UE-A Tx beam (e.g. UE-A spatial domain transmission filter).

[0399] In one example, K is in units of logical time slots in a resource pool. In one example, K is in units of physical time slots. K can be pre-configured and / or configured or updated through RRC signaling from the network and / or RRC signaling on PC5 and / or MAC CE signaling and / or L1 control signaling.

[0400] In one example, K may be specified in the system specification, for example, K=1 or K=2. In one example, if K is not (pre-)configured, a default value specified in the system specification is used, for example, K=1 or K=2.

[0401] In one example, K is the same for all S-SSBs. In one example, different Ks may be configured for each S-SSB or for some S-SSBs.

[0402] In one example, a DCR transmission after S-SSB 0 and no more than K time slots from S-SSB 0 is associated with or linked to a first UE-A Tx beam (e.g., a first UE-A spatial domain transmission filter), a DCR transmission after S-SSB 1 and no more than K time slots from S-SSB 1 is associated with or linked to a second UE-ATx beam (e.g., a second UE-A spatial domain transmission filter), ..., 2 and from Start DCR transmission of no more than K time slots with the first UE-ATx beam (e.g. UE-A spatial domain transmission filter) is associated or linked to the UE-ATx beam (e.g. UE-A spatial domain transmission filter), in Afterwards and from Start DCR transmission of no more than K time slots with the first UE-ATx beam (e.g. UE-A spatial domain transmission filter) is associated or linked to the UE-A Tx beam (e.g. UE-A spatial domain transmission filter).

[0403] In one example, K is in units of logical time slots in a resource pool. In one example, K is in units of physical time slots. K can be pre-configured and / or configured or updated through RRC signaling from the network and / or RRC signaling on PC5 and / or MAC CE signaling and / or L1 control signaling.

[0404] In one example, K may be specified in the system specification, for example, K=1 or K=2. In one example, if K is not (pre-)configured, a default value specified in the system specification is used, for example, K=1 or K=2.

[0405] In one example, K is the same for all S-SSBs. In one example, different Ks may be configured for each S-SSB or for some S-SSBs.

[0406] In one example, a parameter (value) is included in the DCR, wherein the parameter (value) determines or is linked to a UE-A transmit beam (e.g., a UE-A spatial domain transmission filter). In one example, the parameter (value) may be a UE-A transmit beam (e.g., a UE-A spatial domain transmission filter) index. In one example, the parameter (value) is a field in a first stage SCI in a PSCCH channel associated with the DCR. In one example, the parameter (value) is a field in a second stage SCI in a PSSCH channel associated with the DCR. In one example, the parameter (value) is a field in a SL shared channel (SL-SCH) in a PSCCH channel associated with the DCR. In one example, the parameter (value) is a field in a MAC CE associated with the DCR.

[0407] In one example, the DCR includes the SL CSI-RS. In one example, the SL CSI-RS may include and / or indicate the UE-ID. In one example, the SL CSI-RS may include and / or indicate the beam ID.

[0408] In one example, the sequence of SL CSI-RS resources is generated according to:

[0409]

[0410] Where m = 0, 1, ...

[0411] The pseudo-random sequence c(n) is a Gold sequence of length 31, defined as

[0412] c(n)=(x 1 (n+N c )+x 2(n+N c ))mod 2

[0413] in,

[0414] N c =1600

[0415] x 1 (n+31)=(x 1 (n+3)+x 1 (n))mod 2

[0416] x 1 (n+31)=(x 2 (n+3)+x 2 (n+2)+x 2 (n+1)+x 2 (n))mod 2

[0417] The first m sequence is initialized to: x 1 (0) = 1 and x 2 (n) = 0, for n = 1…30.

[0418] The second m-sequence is initialized to c init , where c init

[0419]

[0420] in,

[0421] a) is the number of symbols in a time slot.

[0422] b) is the timeslot number within the frame used for the subcarrier spacing configuration μ.

[0423] c) l is the OFDM symbol number in the time slot.

[0424] d) in, It is the decimal representation of the CRC of the first stage SL control information carried on the PSCCH.

[0425] In one example, the sequence of SL CSI-RS resources is the same for all UE-A transmit beams (UE-A spatial domain transmission filters). In one example, the sequence of SL CSI-RS resources depends on (is a function of) the UE-A transmit beam index (UE-A spatial domain transmission filter index).

[0426] In one example, the sequence n ID Depends on UE-A transmit beam index (UE-A spatial domain transmit filter index).

[0427] In one example, equation c init Depends on UE-A transmit beam index (UE-A spatial domain transmit filter index).

[0428] In one example, the SL CSI-RS resource has a sequence that is a function of a slot number and a symbol number within a frame according to one or more examples described herein. In a variant example, the slot number is a logical slot number. In a variant example, the slot number is a slot number within a subframe, and the slot number and / or symbol determines the beam (or spatial filter) ID based on a mapping between a slot / symbol index and a beam (or spatial filter) ID.

[0429] In one example, a DCR for a first UE (e.g., UE-A) to a second UE (e.g., UE-B) does not implicitly or explicitly indicate to UE-B the UE-A transmit beam index (UE-A spatial domain transmission filter). The DCR from UE-A is transmitted on multiple beams. A response to a particular transmission instance of the DCR allows UE-A to infer (e.g., based on timing) the UE-A transmit beam index (UE-A spatial domain transmission filter) for subsequent transmissions from UE-A to UE-B based on the transmission instance of the DCR for which UE-A received a response from the corresponding UE-B.

[0430] In another example, the response to the DCR sent from UE-B to UE-A includes a signal quality indicator (e.g., SL RSRP or SL SINR as measured by UE-B). In order to determine the UE-A transmit beam index (UE-A spatial domain transmission filter), UE-A may select the transmission instance with the best (e.g., maximum) signal quality indicator (e.g., SL RSRP or SL SINR). Alternatively, UE-A may select any transmission instance with a SL RSRP exceeding a SL RSRP threshold or a SL SINR threshold. The SL RSRP threshold or the SL SINR threshold may be pre-configured and / or configured or updated via RRC signaling from the network and / or RRC signaling on PC5 and / or MAC CE signaling and / or L1 control signaling.

[0431] In one example, if the SL RSRP threshold or SL SINR threshold is not (pre)configured, the default value specified in the system specification is used. In one example, the SL RSRP threshold or SL SINR threshold depends on the priority of the corresponding DCR message. In one example, the SL RSRP may be based on the PSCCH DMRS RSRP or PSSCH DMRS RSRP or SL CSI-RSRSRP. In one example, the SL SINR may be based on the PSCCH DMRS SINR or PSSCH DMRS SINR or SL CSI-RSSINR.

[0432] In another example, the response to the DCR sent from UE-B to UE-A includes one or more corresponding resources for the DCR from UE-A, such as a starting (or ending) time resource (e.g., time slot and / or symbol - this can be absolute or relative to the response) and / or a starting (or ending) frequency resource (e.g., subchannel and / or PRB and / or subcarrier - this can be absolute or relative to the response). In another example, the response to the DCR sent from UE-B to UE-A includes a reference (e.g., an index) to the DCR from UE-A.

[0433] In one example, UE-B receives or attempts to receive a DCR message sent on multiple UE-A transmit beams (e.g., UE-A spatial domain transmission filters). UE-B may check whether it is interested in the announced service type. If UE-B is interested in the announced service type in the DCR message, UE-B may respond in accordance with one or more of the following:

[0434] a) In one example, if the DCR is successfully decoded and UE-B is interested in the advertised service, UE-B sends a response corresponding to the successfully decoded DCR back to UE-A. The message may include information identifying UE-B.

[0435] b) In one example, if the DCR is successfully decoded and the SL RSRP of the DCR exceeds the SL RSRP threshold or the SL SINR of the DCR exceeds the SL SINR threshold and UE-B is interested in the announced service, UE-B sends back a response corresponding to the DCR exceeding the SL RSRP threshold or the SL SINR threshold to UE-A. The SL RSRP or SL SINR can be determined based on the PSCCH DMRS or based on the PSSCH DMRS or based on the SL CSI-RS. The SL RSRP threshold or the SL SINR threshold can be pre-configured, and / or configured or updated via RRC signaling from the network and / or RRC signaling on PC5 and / or MAC CE signaling and / or L1 control signaling. In one example, if the SL RSRP threshold or the SL SINR threshold is not (pre) configured, the default value specified in the system specification is used. In one example, the SL RSRP threshold or the SL SINR threshold depends on the priority of the corresponding DCR message. The message sent by UE-B may include information identifying UE-B.

[0436] c) In one example, if multiple DCR messages are successfully decoded and UE-B is interested in the announced service, UE-B determines the DCR message with the maximum SL RSRP or the maximum SL SINR. The SL RSRP or SL SINR may be determined based on PSCCH DMRS or based on PSSCH DMRS or based on SL CSI-RS. UE-B sends a response corresponding to the determined DCR back to UE-A. In another example, a window may be (pre) configured during which UE-B attempts to receive a DCR message. In one example, the window starts in the time slot of the first successfully decoded DCR (or in the next time slot) and ends after T time slots, where T may be in units of logical time slots in a resource pool. In another example, T may be in units of physical time slots. In one example, T may be pre-configured and / or configured or updated by RRC signaling from the network and / or RRC signaling on PC5 and / or MAC CE signaling and / or L1 control signaling. In one example, T may be specified in the system specification. In one example, if T is not (pre-)configured, a default value specified in the system specification is used.The message sent by UE-B may include information identifying UE-B.

[0437] d) In one example, if multiple DCR messages are successfully decoded and the SL RSRP or SL SINR of the DCR message exceeds the SL RSRP threshold or SL SINR threshold, and UE-B is interested in the announced service, UE-B determines the DCR message with the maximum SL RSRP or SL SINR. UE-B sends a response corresponding to the determined DCR message back to UE-A. SL RSRP or SL SINR can be determined based on PSCCH DMRS or based on PSSCH DMRS or based on SL CSI-RS. The SL RSRP threshold or SL SINR threshold can be pre-configured and / or configured or updated by RRC signaling from the network and / or RRC signaling on PC5 and / or MAC CE signaling and / or L1 control signaling. In one example, if the SL RSRP threshold or SL SINR threshold is not (pre) configured, the default value specified in the system specification is used. In one example, the SL RSRP threshold or SL SINR threshold depends on the priority of the corresponding DCR message. In another example, a window can be (pre) configured during which UE-B attempts to receive a DCR message. In one example, the window starts in the time slot of the first successfully decoded DCR (or in the next time slot) and ends after T time slots, where, in one example, T can be in units of logical time slots in the resource pool. In another example, T can be in units of physical time slots. In one example, T can be pre-configured and / or configured or updated by RRC signaling from the network and / or RRC signaling on PC5 and / or MAC CE signaling and / or L1 control signaling. In one example, T can be specified in the system specification. In one example, if T is not (pre) configured, a default value specified in the system specification is used. The message sent by UE-B may include information identifying UE-B.

[0438] e) In one example, UE-B receives or attempts to receive DCRs corresponding to all transmit beams from UE-A before determining a DCR message to respond to, and UE-B is interested in the advertised service. The message sent by UE-B may include information identifying UE-B. For example, within a (pre)configured window as described herein. In another example, the link establishment messages (e.g., DCRs) may be those sent in one transmit beam scan as described above.

[0439] f) In one example, once UE-B successfully decodes the DCR message and UE-B is interested in the advertised service, UE-B may send a response corresponding to the successfully decoded DCR back to UE-A. In a variation of this example, before UE-B sends the response back to UE-A, it may depend on the implementation of UE-B whether to wait for decoding of other DCR messages (e.g., within a (pre)configured window as described herein). The message sent by UE-B may include information identifying UE-B.

[0440] g) In one example, once UE-B successfully decodes the DCR message, UE-B is interested in the announced service, and the corresponding SL RSRP or SL SINR of the DCR exceeds the SL RSRP threshold or SL SINR threshold, UE-B sends a response corresponding to the DCR exceeding the SL RSRP threshold or SL SINR threshold back to UE-A. The SL RSRP or SL SINR can be determined based on the PSCCH DMRS or based on the PSSCH DMRS or based on the SL CSI-RS. The SL RSRP threshold or SL SINR threshold can be pre-configured and / or configured or updated by RRC signaling from the network and / or RRC signaling on PC5 and / or MAC CE signaling and / or L1 control signaling. In one example, if the SL RSRP threshold or SL SINR threshold is not (pre) configured, the default value specified in the system specification is used. In one example, the SL RSRP threshold or SL SINR threshold depends on the priority of the corresponding DCR message. In a variation of this example, before UE-B sends a response back to UE-A, it may depend on whether the implementation of UE-B waits for decoding other DCR messages. In one example, if UE-B waits, the decoded DCR may be within a (pre-)configured window as described herein.The message sent by UE-B may include information identifying UE-B.

[0441] h) In one example, if there is no DCR message with a SL RSRP exceeding a SL RSRP threshold at UE-B or a SL SINR exceeding a SLSINR threshold, and if UE-B is interested in the announced service, UE-B receives or attempts to receive DCRs corresponding to all transmit beams from UE-A before determining a DCR message to respond to. In one example, the decoded DCR may be within a (pre)configured window as described herein. In another example, the link establishment messages (e.g., DCRs) may be those sent in a transmit beam scan as described above. UE-B determines the DCR message with the maximum SL RSRP or SL SINR. The SL RSRP or SL SINR may be determined based on the PSCCH DMRS or based on the PSSCH DMRS or based on the SLCSI-RS. The SL RSRP threshold or SL SINR threshold may be preconfigured and / or configured or updated by RRC signaling from the network and / or RRC signaling on PC5 and / or MAC CE signaling and / or L1 control signaling. In one example, if the SL RSRP threshold or SL SINR threshold is not (pre-)configured, a default value specified in the system specification is used. In one example, the SL RSRP threshold or SL SINR threshold depends on the priority of the corresponding DCR message. The message sent by UE-B may include information identifying UE-B.

[0442] i) In one example, UE-A repeats the DCR message on the same transmit beam (spatial domain transmission filter). If UE-B is interested in the announced service, UE-B attempts to receive the repeated DCR using a different receive beam (spatial domain reception filter) to discover the best receiver beam (spatial domain reception filter) to use (at UE-B). In one example, the resource pool can be (pre)configured whether repetition is on or off. Repetition can be pre-configured and / or configured or updated by RRC signaling from the network and / or RRC signaling on PC5 and / or MAC CE signaling and / or L1 control signaling. In one example, if repetition is not (pre)configured, the default value specified in the system specification is used. When repetition is on, UE-B can assume that the DCR message is repeated using the same transmit beam (spatial domain transmission filter) as UE-A. When repetition is off, UE-B cannot assume that the DCR message is repeated using the same transmit beam (spatial domain transmission filter) as UE-A. When repetition is turned on, the resource pool may be (pre)configured with a repetition count M, where M is the number of DCR transmissions on the same transmit beam (spatial domain transmission filter) from UE-A. M may be preconfigured and / or configured or updated by RRC signaling from the network and / or RRC signaling on PC5 and / or MACCE signaling and / or L1 control signaling. In one example, if M is not (pre)configured, a default value specified in the system specification is used. The message sent by UE-B may include information identifying UE-B.

[0443] Fig.17 An example of transmit and receive beam scanning 1700 according to an embodiment of the present disclosure is shown. For example, any of UEs 111-116 may perform SL communication using beam scanning 1700. This example is for illustration only, and other embodiments may be used without departing from the scope of the present disclosure.

[0444] In one example, after a UE (e.g., UE-B) determines a corresponding transmit beam (or spatial domain transmission filter) and DCR from UE-A according to one or more examples described herein, and wherein UE-B is interested in the advertised service, UE-B sends a response, signal, or message to UE-A, wherein the response, signal, or message indicates the transmit beam (or spatial domain transmission filter) from UE-A. The message sent by UE-B may include information identifying UE-B.

[0445] In one example, the response is a PSFCH transmission corresponding to the DCR of the transmit beam (or spatial domain transmission filter) from UE-A. There is a relationship between the DCR (e.g., transmitted on the PSCCH / PSSCH) and the corresponding PSFCH resource. By receiving the PSFCH, UE-A will be able to determine the corresponding PSCCH / PSSCH and the associated transmit beam (spatial domain transmission filter) of the DCR. This can be the spatial domain filter that UE-A uses for subsequent transmissions to UE-B.

[0446] In one example, if UE-B is interested in the announced service, UE-B sends PSFCH. PSFCH can also instruct UE-B to send a response. For example, each UE-B can be identified by the cyclic shift / PRB of PSFCH or the PSFCH resource used.

[0447] In another example, the PSFCH response includes a positive acknowledgement. In another example, the PSFCH response includes a negative acknowledgement. The retransmission of the DCR uses the transmit beam (spatial domain transmit filter) of the negatively acknowledged DCR.

[0448] In one example, UE-A receives multiple PSFCH transmissions in response to DCR messages sent on multiple transmit beams (spatial domain transmission filters) for the same UE-B. UE-A may also receive PSFCH responses from other UE-Bs. UE-A may select a transmit beam (spatial domain transmission filter) corresponding to one of the DCRs with the received PSFCH for each UE-B.

[0449] In one example, UE-A may select a transmit beam (spatial domain transmission filter) corresponding to the DCR associated with the strongest received PSFCH for each UE-B. In one example, UE-A may select a transmit beam (spatial domain transmission filter) corresponding to the DCR associated with the PSFCH including a positive acknowledgment of each UE-B. In one example, UE-A may select a transmit beam (spatial domain transmission filter) corresponding to the DCR associated with the strongest received PSFCH including a positive acknowledgment of each UE-B.

[0450] In one example, according to one or more examples described herein, if UE-B receives multiple DCRs that are successfully decoded and UE-B is interested in the announced service, UE-B only sends a PSFCH with a positive acknowledgement for one of the successfully decoded DCRs (e.g., the DCR associated with the preferred transmit beam (or spatial domain transmission filter)). In one example, if UE-B receives multiple DCRs that are successfully decoded and UE-B is interested in the announced service, UE-B may send a PSFCH with a positive acknowledgement for the successfully decoded DCR or a subset of the successfully decoded DCRs.

[0451] In one example, there is no PSFCH transmission corresponding to the DCR.Instead, UE-B may indicate a preferred transmit beam (spatial domain transmit filter) from UE-A using one or more of the examples described herein.

[0452] In one example, the response is a PSCCH transmission corresponding to the DCR of the transmit beam (or spatial domain transmission filter) from UE-A. There may be a fixed relationship between the DCR and the PSCCH transmission. For example, a fixed time offset between the DCR (e.g., associated with the preferred transmit beam (or spatial domain transmission filter) from UE-A) and the PSCCH transmission determined according to one or more examples described herein.

[0453] In another example, there is a mapping between resources (eg, associated with a preferred transmit beam (or spatial domain transmit filter) from UE-A) and PSCCH transmissions for a DCR determined according to one or more examples described herein.

[0454] In another example, a DCR determined according to one or more examples described herein (e.g., associated with a preferred transmit beam (or spatial domain transmit filter) from UE-A) indicates resources for corresponding PSCCH transmission. If UE-B is interested in the service announced in the DCR, UE-B sends the PSCCH.

[0455] In one example, the PSCCH may include an indication of the UE-B identity or index. In one example, the identity or index of UE-B is explicitly indicated in the PSCCH (e.g., part of the payload). In another example, the identity or index of UE-B is implicitly indicated by the PSCCH, for example, by a sequence of the PSCCH DMRS or a sequence scrambled to the CRC, etc.

[0456] In one example, the time slot of the link establishment message (e.g., DCR) - time slot n - the time slot of the determination response message (e.g., PSCCH) - time slot m - for example, m = n + D, m ≥ n + D or m> n + D, where D can be pre-configured and / or configured or updated via RRC signaling from the network and / or RRC signaling on PC5 and / or MAC CE signaling and / or L1 control signaling.

[0457] In one example, D may be specified in the system specification. In one example, if D is not (pre)configured, a default value specified in the system specification is used.

[0458] In one example, m and / or n and / or D may be in a logical time slot of a resource pool. In one example, m and / or n and / or D may be in a logical time slot that may be in a resource pool. In one example, m and / or n and / or D may be in a physical time slot or physical time.

[0459] In one example, UE-A receives multiple PSCCH transmissions in response to DCR messages sent on multiple transmit beams (spatial domain transmission filters) for the same UE-B. UE-A may also receive PSCCH responses from other UE-Bs. UE-A may select, for each UE-B transmission, a transmit beam (spatial domain transmission filter) corresponding to one of the DCRs with the received PSCCH.

[0460] In one example, UE-A may select a transmit beam (spatial domain transmit filter) that corresponds to the DCR associated with the strongest received PSCCH transmission for each UE-B.

[0461] In one example, if UE-B receives multiple DCRs that are successfully decoded and UE-B is interested in the announced service, then according to one or more examples described herein, UE-B only sends a PSCCH transmission for one of the successfully decoded DCRs (e.g., a DCR associated with a preferred transmit beam (or spatial domain transmit filter)).

[0462] In one example, if UE-B receives multiple DCRs that are successfully decoded and UE-B is interested in the advertised service, UE-B may send a PSCCH transmission for the successfully decoded DCRs or a subset of the successfully decoded DCRs.

[0463] In one example, the PSCCH transmission includes a quality metric for the corresponding DCR. For example, the quality metric may be the SL RSRP (PSCCH RSRP or PSSCH RSRP or SL CSI-RS RSRP) of the DCR. In another example, the quality metric may be the SL SINR (PSCCH SINR or PSSCH SINR or SL CSI-RS SINR) of the DCR.

[0464] In a further example, UE-A may determine a transmit beam (spatial domain transmission filter) from UE-A for subsequent transmissions to each UE-B based at least on a quality metric from the corresponding UE-B.

[0465] In one example, in response to one or more DCR transmissions (e.g., transmissions associated with multiple transmit beams (spatial domain transmission filters) from UE-A), and if UE-B is interested in the announced service, UE-B sends a PSCCH transmission. The PSCCH transmission includes an indication of a determined DCR according to one or more examples described herein, such as a DCR associated with a preferred transmit beam (or spatial domain transmission filter) from UE-A. If UE-B is interested in the service announced in the DCR, UE-B sends the PSCCH.

[0466] In one example, the PSCCH may include an indication of a UE-B identity or index.

[0467] In one example, the identity or index of UE-B is explicitly indicated in the PSCCH (eg, part of the payload).

[0468] In another example, the identity or index of UE-B is implicitly indicated by the PSCCH, for example, by a sequence of a PSCCH DMRS or a sequence used to scramble the CRC, etc.

[0469] In one example, the PSCCH transmission is sent multiple times on different transmit beams (or spatial domain transmit filters) from UE-B for transmit beam scanning from UE-B.

[0470] In one example, the response is a PSCCH / PSSCH transmission corresponding to the DCR of the transmit beam (or spatial domain transmission filter) from UE-A. There may be a fixed relationship between the DCR and the PSCCH / PSSCH transmission. For example, a fixed time offset between the DCR (e.g., associated with the preferred transmit beam (or spatial domain transmission filter) from UE-A) and the PSCCH / PSSCH transmission determined according to one or more examples described herein.

[0471] In another example, there is a mapping between resources used for determining a DCR (e.g., associated with a preferred transmit beam (or spatial domain transmit filter) from UE-A) according to one or more examples described herein and PSCCH / PSSCH transmissions.

[0472] In another example, a DCR determined according to one or more examples described herein (e.g., associated with a preferred transmit beam (or spatial domain transmit filter) from UE-A) indicates resources for corresponding PSCCH / PSSCH transmissions. If UE-B is interested in the service announced in the DCR, UE-B sends the PSCCH / PSSCH.

[0473] In one example, the PSCCH / PSSCH may include an indication of the UE-B identity or index. In one example, the identity or index of UE-B is explicitly indicated in the PSCCH (e.g., part of the payload) or in the PSSCH (e.g., as a field in the second stage SCI), or is included in the SL-SCH or is included in the MAC CE. In another example, the identity or index of UE-B is implicitly indicated by the PSCCH or PSSCH, for example, by a sequence of PSCCH DMRS or PSSCH DMRS or a sequence of associated SL CSI-RS or a sequence for scrambling the CRC of the PSCCH or the CRC of the second stage SCI or the CRC of the SL shared channel, etc.

[0474] In one example, the time slot of the link establishment message (e.g., DCR) - time slot n - determines the time slot of the response message (e.g., PSCCH / PSCCH) - time slot m - for example, m=n+D, m≥n+D or m>n+D, where D can be pre-configured and / or configured or updated via RRC signaling from the network and / or RRC signaling on PC5 and / or MAC CE signaling and / or L1 control signaling.

[0475] In one example, D may be specified in the system specification. In one example, if D is not (pre)configured, a default value specified in the system specification is used.

[0476] In one example, m and / or n and / or D may be in a logical time slot of a resource pool. In one example, m and / or n and / or D may be in a logical time slot that may be in a resource pool. In one example, m and / or n and / or D may be in a physical time slot or physical time.

[0477] In one example, UE-A receives multiple PSCCH / PSSCH transmissions in response to DCR messages sent on multiple transmit beams (spatial domain transmission filters) for the same UE-B. UE-A may also receive PSCCH / PSSCH responses from other UE-Bs. UE-A may select, for each UE-B, a transmit beam (spatial domain transmission filter) corresponding to one of the DCRs having the received PSCCH / PSSCH transmissions.

[0478] In one example, UE-A may select a transmit beam (spatial domain transmit filter) corresponding to the DCR associated with the strongest received PSCCH / PSSCH transmission for each UE-B or the strongest SL CSI-RS associated with or included in the PSCCH / PSSCH.

[0479] In one example, if UE-B receives multiple DCRs that are successfully decoded and UE-B is interested in the announced service, then according to one or more examples described herein, UE-B sends a PSCCH / PSSCH transmission only for one of the successfully decoded DCRs (e.g., the DCR associated with the preferred transmit beam (or spatial domain transmit filter)).

[0480] In one example, if UE-B receives multiple successfully decoded DCRs and UE-B is interested in the advertised service, UE-B may send a PSCCH / PSSCH transmission for the successfully decoded DCRs or a subset of the successfully decoded DCRs.

[0481] In one example, the PSCCH / PSSCH transmission includes a quality metric for the corresponding DCR. For example, the quality metric may be the SL RSRP of the DCR (PSCCH RSRP or PSSCH RSRP or SL CSI-RS RSRP). In another example, the quality metric may be the SL SINR of the DCR (PSCCH SINR or PSSCH SINR or SL CSI-RS SINR).

[0482] In another example, UE-A may determine a transmit beam (spatial domain transmit filter) from UE-A for subsequent transmissions to each UE-B based at least on a quality metric from the corresponding UE-B. In one example, the quality metric may be in the first stage SCI (e.g., in the PSCCH). In another example, the quality metric may be in the second stage SCI (e.g., in the PSSCH). In another example, the quality metric may be in the SL shared channel (e.g., in the PSSCH). In another example, the quality metric may be in the MAC CE.

[0483] In one example, in response to one or more DCR transmissions (e.g., transmissions associated with multiple transmit beams (spatial domain transmission filters) from UE-A), and if UE-B is interested in the announced service, UE-B sends a PSCCH / PSSCH transmission. The PSCCH / PSSCH transmission includes an indication of a determined DCR according to one or more examples herein, for example, a DCR associated with a preferred transmit beam (or spatial domain transmission filter) from UE-A. In one example, the indication may be in a first stage SCI (e.g., in the PSCCH). In another example, the indication may be in a second stage SCI (e.g., in the PSSCH). In another example, the indication may be in a SL shared channel (e.g., in the PSSCH). In another example, the indication may be in a MAC CE.

[0484] If UE-B is interested in the service announced in the DCR, UE-B sends the PSCCH / PSSCH. In one example, the PSCCH / PSSCH may include an indication of the UE-B identity or index.

[0485] In one example, the identity or index of UE-B is explicitly indicated in PSCCH (e.g., part of the payload) or in PSSCH (e.g., as a field in the second stage SCI) or is included in SL-SCH or is included in MAC CE. In another example, the identity or index of UE-B is implicitly indicated by PSCCH or PSSCH, for example, by a sequence of PSCCH DMRS or PSSCH DMRS or a sequence of SL CSI-RS or a sequence of CRC scrambled on PSCCH or CRC of the second stage SCI or CRC of the SL shared channel, etc.

[0486] In one example, PSCCH / PSSCH transmissions are sent multiple times on different transmit beams (or spatial domain transmit filters) from UE-B for transmit beam scanning from UE-B.

[0487] In one example, a response to a DCR transmitted on a plurality of transmit beams (spatial domain transmission filters) from UE-A indicating the determined DCR and its associated transmit beams (spatial domain transmission filters) is included in (or is part of) a security establishment procedure, e.g., Figure 7 Step 740.

[0488] In one example, UE-B may determine a transmit beam for a response message to UE-A based on beam correspondence or beam reciprocity between UE-B's transmit beam (or spatial domain transmit filter) and UE-B's receive beam (or spatial domain receive filter), for example, PSFCH (if applicable) according to one or more examples herein, PSCCH according to one or more examples herein, PSCCH / PSSCH according to one or more examples herein, and security establishment procedures according to one or more examples herein. The receive beam (or spatial domain receive filter) of UE-B for receiving a DCR (e.g., a DCR determined according to one or more examples herein) determines the transmit beam (or spatial domain transmit filter) that UE-B uses to send a response to UE-A.

[0489] In one example, if UE-B is interested in the service announced in the DCR, UE-B sends a response to the DCR. In another example, the response message according to one or more examples herein is repeated multiple times on the same transmit beam (spatial domain transmission filter) from UE-B to allow UE-A to perform Rx beam scanning and find a preferred Rx beam (spatial domain reception filter) at UE-A for transmission to the corresponding UE-B.

[0490] In another example, UE-A determines its receive beam (spatial domain receive filter) based on beam correspondence (beam reciprocity) using UE-A's transmit beam (spatial domain receive filter) corresponding to DCR sent from UE-A.

[0491] For example, if UE-A transmits a message in time slot n and expects to receive a response in time slot m, UE-A determines the Rx beam of time slot m based on the beam correspondence with the TX beam used in time slot n.

[0492] In one example, a response message from UE-B (e.g., a PSFCH (if applicable) according to one or more examples herein, a PSCCH according to one or more examples herein, a PSCCH / PSSCH according to one or more examples herein, and a security establishment procedure according to one or more examples described herein) is sent from UE-B on multiple transmit beams (spatial domain transmission filters). The transmissions in the multiple beams may be in different time and / or frequency and / or code (e.g., cyclic shifts of the PSFCH, if applicable) resources. UE-A may determine a transmission from each UE-B that corresponds to a transmit beam (e.g., a spatial domain transmission filter) from the corresponding UE-B that is preferred for subsequent transmissions from the corresponding UE-B. UE-A may, for example, signal the preferred transmission to the corresponding UE-B using one of the previous examples, where the roles of UE-A and UE-B are switched. UE-A can determine the preferred transmission and the corresponding preferred transmit beam (e.g., spatial domain transmission filter) from UE-B based on a quality metric (e.g., SL RSPR), where the SL RSRP can be based on PSCCH DMRS RSRP or PSSCH DMRS RSRP or SL CSI-RS RSRP, or SL SINR, where the SL SINR can be based on PSCCH DMRS SINR or PSSCH DMRS SINR or SL CSI-RS RSRP.

[0493] In one example, if UE-B is interested in the service announced in the DCR, UE-B sends a response to the DCR. In another example, the response message according to one or more examples described herein is repeated multiple times on each transmit beam (spatial domain transmit filter) from UE-B (in addition to having multiple Tx beams) to allow UE-A to perform Rx beam scanning and find a preferred Rx beam (spatial domain receive filter) at UE-A for transmission to the corresponding UE-B.

[0494] In another example, UE-A determines its receive beam (spatial domain receive filter) based on beam correspondence (beam reciprocity) using the transmit beam (spatial domain receive filter) of UE-A corresponding to the DCR sent from UE-A. For example, if UE-A transmits a message in time slot n and expects to receive a response in time slot m, UE-A determines the Rx beam of time slot m based on the beam correspondence with the TX beam used in time slot n.

[0495] According to one or more examples described herein, when UE-B receives one or more link establishment messages from UE-A, the response from UE-B may be:

[0496] a) In one example, each response from UE-B corresponds to one of the messages received from UE-A. In a sub-example, UE-B may send one message (e.g., if UE-B receives (e.g., successfully decodes) more than one link establishment message, UE-B may select one of them based on the aforementioned example and send a corresponding response). In a sub-example, UE-B may send multiple messages (e.g., if UE-B receives (e.g., successfully decodes) more than one link establishment message, UE-B may select some or all of them based on the aforementioned example and send a corresponding response for each message).

[0497] b) In one example, the response from UE-B corresponds to one or more messages received from UE-A. For example, a single response message may be sent for a link setup message (or a subset of received link setup messages) received at UE-B from UE-A. UE-B may select one, some, or all of the received link setup messages to include in a message sent to UE-A based on the selection criteria described above.

[0498] c) In one example, the response from UE-B may be PSFCH and / or PSCCH and / or PSCCH / PSSCH (eg, second stage SCI and / or first stage SCI) and / or PSCCH / PSSCH (eg, MAC CE).

[0499] Fig.18 An example method 1800 performed by a UE in a wireless communication system according to an embodiment of the present disclosure is shown. Fig.18 The method 1800 may be performed by Figure 1 One of the UEs 111-116 (such as Figure 3 The method 1800 is for illustration only, and other embodiments may be used without departing from the scope of the present disclosure.

[0500] Method 1800 begins with the UE sending a first PSCCH and a corresponding first PSSCH to a second UE using multiple spatial domain transmission filters, respectively (1810). For example, in 1810, the first PSCCH and the corresponding first PSSCH include a first link establishment message. In various embodiments, the PSCCH in the first PSCCH and the corresponding PSSCH in the corresponding first PSSCH are repeated multiple times using the same spatial domain transmission filter in multiple spatial domain transmission filters. In various embodiments, the retransmission of the PSCCH in the first PSCCH and the corresponding PSSCH in the corresponding first PSSCH uses the spatial domain transmission filter for the corresponding earlier transmission. In various embodiments, the UE receives a PSFCH corresponding to the PSSCH from the corresponding first PSSCH. The spatial domain transmission filter is a filter for sending the PSSCH. The PSFCH includes a positive confirmation.

[0501] The UE then receives auxiliary information associated with the spatial domain transmission filter from the second UE (1820). For example, in 1820, the auxiliary information includes a quality metric related to the first PSCCH and the corresponding PSSCH. In various embodiments, the PSSCH in the corresponding first PSSCH includes a SL CSI-RS.

[0502] Then, the UE determines a spatial domain transmission filter based on the auxiliary information (1830). Then, the UE transmits a second PSSCH and a corresponding second PSSCH to a second UE based on the spatial domain transmission filter (1840).

[0503] In various embodiments, the UE may also receive a third PSCCH and a corresponding third PSSCH from a third UE. For example, the third PSCCH and the corresponding third PSSCH include a second link establishment message. The UE's measurement metric is associated with the third PSCCH and the corresponding third PSSCH. In various embodiments, the metric is based on the SLRSRP measurement corresponding to the third PSCCH and the corresponding third PSSCH. The UE determines a second spatial domain receive filter to receive a signal from the third UE. The UE sends a second auxiliary information based on the metric to the third UE. The UE receives a subsequent signal from the third UE using the second spatial domain receive filter. The UE receives information indicating the SLRSRP threshold. The UE determines the PSCCH from the third PSCCH and the corresponding PSSCH from the corresponding third PSSCH based on one of the following: the RSRP of the PSCCH DMRS exceeds the RSRP threshold, the RSRP of the PSSCH DMRS exceeds the RSRP threshold, or the RSRP of the CSI-RS associated with the corresponding PSSCH exceeds the RSRP threshold. The UE sends a PSFCH corresponding to the PSCCH and the corresponding PSSCH. In one example, the second auxiliary information is included in the PSFCH or indicated by the PSFCH.

[0504] Fig.19 The structure of a base station according to an embodiment of the present disclosure is shown.

[0505] like Fig.19 As shown, the base station according to the embodiment may include a transceiver 1910, a memory 1920, and a processor 1930. The transceiver 1910, the memory 1920, and the processor 1930 of the base station may operate according to the communication method of the above-mentioned base station. However, the components of the base station are not limited thereto. For example, the base station may include more or fewer components than the above-mentioned components. In addition, the processor 1930, the transceiver 1910, and the memory 1920 may be implemented as a single chip. In addition, the processor 1930 may include at least one processor. In addition, Fig.19 The base station corresponds to Figure 2 base station.

[0506] The transceiver 1910 is collectively referred to as a base station receiver and a base station transmitter, and can send signals to / receive signals from a terminal (UE) or a network entity. The signals sent to or received from a terminal or a network entity may include control information and data. The transceiver 1910 may include an RF transmitter for up-converting and amplifying the frequency of the transmitted signal, and an RF receiver for amplifying the frequency of the low noise and down-converting the received signal. However, this is only an example of the transceiver 1910, and the components of the transceiver 1910 are not limited to the RF transmitter and the RF receiver.

[0507] In addition, the transceiver 1910 may receive a signal and output a signal to the processor 1930 through a wireless channel, and transmit a signal output from the processor 1930 through a wireless channel.

[0508] The memory 1920 may store programs and data required for the operation of the base station. In addition, the memory 1920 may store control information or data included in a signal obtained by the base station. The memory 1920 may be a storage medium such as a read-only memory (ROM), a random access memory (RAM), a hard disk, a CD-ROM, and a DVD, or a combination of storage media.

[0509] The processor 1930 may control a series of processes so that the base station operates as described above. For example, the transceiver 1910 may receive a data signal including a control signal transmitted by a terminal, and the processor 1930 may determine a result of receiving the control signal and the data signal transmitted by the terminal.

[0510] Fig. 20 The structure of a UE according to an embodiment of the present disclosure is shown.

[0511] like Fig. 20 As shown, the UE according to the embodiment may include a transceiver 2010, a memory 2020, and a processor 2030. The transceiver 2010, the memory 2020, and the processor 2030 of the UE may operate according to the communication method of the above-mentioned UE. However, the components of the UE are not limited thereto. For example, the UE may include more or fewer components than the above-mentioned components. In addition, the processor 2030, the transceiver 2010, and the memory 2020 may be implemented as a single chip. In addition, the processor 2030 may include at least one processor. In addition, Fig. 20 The UE corresponds to Figure 3 UE116.

[0512] The transceiver 2010 is collectively referred to as a UE receiver and a UE transmitter, and can send / receive signals to / from a base station or a network entity. The signals sent to or received from a base station or a network entity may include control information and data. The transceiver 2010 may include an RF transmitter for up-converting and amplifying the frequency of the transmitted signal, and an RF receiver for amplifying the low noise and down-converting the frequency of the received signal. However, this is only an example of the transceiver 2010, and the components of the transceiver 2010 are not limited to the RF transmitter and the RF receiver.

[0513] In addition, the transceiver 2010 may receive a signal through a wireless channel and output the signal to the processor 2030 , and transmit a signal output from the processor 2030 through a wireless channel.

[0514] The memory 2020 may store programs and data required for the operation of the UE. In addition, the memory 2020 may store control information or data included in a signal obtained by the UE. The memory 2020 may be a storage medium such as a read-only memory (ROM), a random access memory (RAM), a hard disk, a CD-ROM, and a DVD, or a combination of storage media.

[0515] The processor 2030 may control a series of processes so that the UE operates as described above. For example, the transceiver 2010 may receive a data signal including a control signal sent by a base station or a network entity, and the processor 2030 may determine a result of receiving the control signal and the data signal sent by the base station or the network entity.

[0516] Those skilled in the art will appreciate that the various illustrative logic blocks, modules, circuits and steps described in the present application can be implemented as hardware, software or a combination of the two. In order to clearly illustrate this interchangeability between hardware and software, various illustrative components, blocks, modules, circuits and steps are generally described above in the form of their functional set. Whether such a functional set is implemented as hardware or software depends on specific applications and the design constraints imposed on the entire system. The technician can implement the described functional set in different ways for each specific application, but such design decisions should not be interpreted as causing a departure from the scope of the present application.

[0517] In the above-mentioned embodiments of the present disclosure, all operations and messages may be selectively performed or may be omitted. In addition, the operations in each embodiment do not need to be performed in sequence, and the order of the actions may be different. Messages do not need to be sent in sequence, and the order in which messages are sent may be changed. Each operation and transmission of each message may be performed independently.

[0518] Although the drawings show different examples of user equipment, various changes may be made to the drawings. For example, the user equipment may include any number of each component in any suitable arrangement. Generally, the drawings do not limit the scope of the present disclosure to any particular configuration. In addition, although the drawings show operating environments in which various user equipment features disclosed in this patent document may be used, these features may be used in any other suitable system.

[0519] The various illustrative logical blocks, modules, and circuits described in this application may be implemented or performed by a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in an alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices, for example, a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in cooperation with a DSP core, or any other such configuration.

[0520] The steps of the method or algorithm described in this application can be directly embodied in hardware, in a software module executed by a processor, or in a combination thereof. The software module can reside in a RAM memory, a flash memory, a ROM memory, an EPROM memory, an EEPROM memory, a register, a hard disk, a removable disk, or any other form of storage medium known in the art. The storage medium is coupled to the processor so that the processor can read and write information from / to the storage medium. In an alternative, the storage medium can be integrated into the processor. The processor and the storage medium can reside in an ASIC. The ASIC can reside in a user terminal. In an alternative, the processor and the storage medium can reside in a user terminal as discrete components.

[0521] In one or more designs, the functions may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, each function may be stored on or delivered by one or more instructions or codes on a computer-readable medium. Computer-readable media include both computer storage media and communication media, the latter including any media that facilitates the transfer of a computer program from one place to another. Storage media may be any available media that can be accessed by a general or special purpose computer.

[0522] While the present disclosure has been shown and described with reference to various embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present disclosure as defined by the appended claims and their equivalents.

Claims

1. A first user equipment (UE) in a wireless communication system, the first UE comprising: Transceiver; and at least one processor coupled to the transceiver, the at least one processor configured to: sending a first physical sidelink control channel (PSCCH) and a corresponding first physical sidelink shared channel (PSSCH) to a second UE using a plurality of spatial domain transmission filters, respectively, wherein the first PSCCH and the corresponding first PSSCH include a first link establishment message, receiving auxiliary information associated with the spatial domain transmission filter from a second UE, Determine the spatial domain transmission filter based on the auxiliary information, Based on the spatial domain transmission filter, a second PSCCH and a corresponding second PSSCH are sent to the second UE.

2. The first UE according to claim 1, wherein: The PSCCH in the first PSCCH and the corresponding PSSCH in the corresponding first PSSCH are repeated a plurality of times using the same spatial domain transmit filter among the plurality of spatial domain transmit filters.

3. The first UE according to claim 1, wherein: The auxiliary information includes quality metrics related to the first PSCCH and the corresponding first PSSCH.

4. The first UE according to claim 1, wherein: The PSSCH in the corresponding first PSSCH includes a sidelink (SL) channel state information reference signal (CSI-RS).

5. A second user equipment (UE) in a wireless communication system, the second UE comprising: Transceiver; and at least one processor coupled to the transceiver, the at least one processor configured to: receiving a first physical sidelink control channel (PSCCH) and a corresponding first physical sidelink shared channel (PSSCH) from a first UE using a plurality of spatial domain transmission filters, respectively, wherein the first PSCCH and the corresponding first PSSCH include a first link establishment message, sending auxiliary information associated with the spatial domain transmission filter to the first UE, receiving a second PSCCH and a corresponding second PSSCH from the first UE based on the spatial domain transmission filter, Among them, the spatial domain transmission filter is determined based on the auxiliary information.

6. The second UE according to claim 5, wherein: The PSCCH in the first PSCCH and the corresponding PSSCH in the corresponding first PSSCH are repeated a plurality of times using the same spatial domain transmit filter among the plurality of spatial domain transmit filters.

7. The second UE according to claim 5, wherein: The auxiliary information includes quality metrics related to the first PSCCH and the corresponding first PSSCH.

8. The second UE according to claim 5, wherein: The PSSCH in the corresponding first PSSCH includes a sidelink (SL) channel state information reference signal (CSI-RS).

9. A method performed by a first user equipment (UE) in a wireless communication system, the method comprising: Sending a first physical sidelink control channel (PSCCH) and a corresponding first physical sidelink shared channel (PSSCH) to a second UE using a plurality of spatial domain transmission filters respectively, wherein the first PSCCH and the corresponding first PSSCH include a first link establishment message; receiving, from a second UE, assistance information associated with a spatial domain transmission filter; determining a spatial domain transfer filter based on the side information; and Based on the spatial domain transmission filter, a second PSCCH and a corresponding second PSSCH are sent to the second UE.

10. The method according to claim 9, wherein: The PSCCH in the first PSCCH and the corresponding PSSCH in the corresponding first PSSCH are repeated a plurality of times using the same spatial domain transmit filter among the plurality of spatial domain transmit filters.

11. The method according to claim 9, wherein: The auxiliary information includes quality metrics related to the first PSCCH and the corresponding first PSSCH.

12. The method according to claim 9, wherein: The PSSCH in the corresponding first PSSCH includes a sidelink (SL) channel state information reference signal (CSI-RS).

13. A method performed by a second user equipment (UE) in a wireless communication system, the method comprising: Receiving a first physical sidelink control channel (PSCCH) and a corresponding first physical sidelink shared channel (PSSCH) from a first UE using a plurality of spatial domain transmission filters, respectively, wherein the first PSCCH and the corresponding first PSSCH include a first link establishment message; sending auxiliary information associated with the spatial domain transmit filter to the first UE; and receiving a second PSCCH and a corresponding second PSSCH from the first UE based on the spatial domain transmission filter, Among them, the spatial domain transmission filter is determined based on the auxiliary information.

14. The method according to claim 13, wherein: The PSCCH in the first PSCCH and the corresponding PSSCH in the corresponding first PSSCH are repeated a plurality of times using the same spatial domain transmit filter among the plurality of spatial domain transmit filters.

15. The method according to claim 13, wherein: The auxiliary information includes a quality metric related to the first PSCCH and the corresponding first PSSCH, and Among them, the PSSCH in the corresponding first PSSCH includes a side link (SL) channel state information reference signal (CSI-RS).

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