Sidelink Beam Management

Abstract

In accordance with a method, an apparatus, and a system for beam management for a first user equipment (UE) in sidelink communications are disclosed. The method includes: establishing, by the first UE, beam alignment with a second UE using a first beam; receiving, for the second UE, a second beam assistance indication indicating at least one of time information or frequency information associated with the second beam; transmitting a second beam configuration; receiving a confirmation of the second beam configuration; determining whether selection of resources associated with use of the second beam is triggered; updating a candidate resource set and selecting one or more resources from the updated candidate resource set in response to determining that resource selection is triggered; and transmitting one or more signals or messages using the one or more resources selected from the updated candidate resource set.

Description

[Technical Field]

[0001] [Cross-reference to related patent applications] This application claims the benefit of U.S. Provisional Application No. 63 / 445,884, filed February 15, 2023, entitled "SIDELINK BEAM MANAGEMENT," the entire contents of which are incorporated herein by reference.

[0002] Apparatus and methods consistent with the present disclosure relate generally to communications, and more particularly to methods, systems, and devices for beam management in sidelink communications. [Background technology]

[0003] Sidelink communication technology enables direct communication between two or more devices, such as two or more vehicles in vehicle-to-everything (V2X) communication. In sidelink communication, when a transmitter device transmits data to a receiver device using a narrow beam, the receiver device can receive the data using either a wide receive beam or a narrow receive beam. A wide receive beam may enable stable reception for the receiver device even when one or more other devices are simultaneously transmitting data to the receiver device in sidelink communication with the transmitter device. However, continuously using a wide receive beam may be impractical, especially for high-frequency wireless signals that require narrow beams to be concentrated to compensate for high path loss. On the other hand, using a narrow receive beam may provide advantages to the receiver device, especially in high-frequency sidelink communication. However, the beam correspondence between the narrow receive beam and the narrow transmit beam may easily be lost. Furthermore, when one or more other devices are simultaneously transmitting data to the receiver device with the transmitter device, the narrow receive beam may prevent the receiver device from simultaneously receiving transmissions from multiple devices. A system and method for flexible and efficient sidelink beam management is needed. Summary of the Invention

[0004] According to some embodiments of the present disclosure, a user equipment (UE) for sidelink communication is provided, including: a memory that stores instructions; and a processor configured to execute the instructions stored in the memory to establish beam alignment with a second UE using a first beam, receive from the second UE a second beam-assistance indication indicating at least one of time information or frequency information associated with the second beam for reception of signals or data from the first UE, transmit a second beam configuration to the second UE in response to receiving the second beam-assistance indication, receive from the second UE a confirmation of the second beam configuration, determine whether selection of resources associated with use of the second beam has been triggered, update a candidate resource set in response to determining that resource selection has been triggered, select one or more resources from the updated candidate resource set such that the selected one or more resources are associated with use of the second beam, and transmit one or more signals or messages using the selected one or more resources from the updated candidate resource set.

[0005] According to some embodiments of the present disclosure, a second UE for sidelink communication is provided, the second UE including a memory storing instructions, and executing the instructions stored in the memory to establish beam alignment with the first UE using a first beam, and to transmit a second beam-assistance indication to the first UE indicating at least one of time information or frequency information associated with the second beam for reception of signals or data from the first UE. and a processor configured to transmit a second beam configuration to the first UE, and in response to transmitting the second beam assistance indication, receive a second beam configuration from the first UE, and transmit a confirmation of the second beam configuration to the first UE.

[0006] According to some embodiments of the present disclosure, a method for beam management in sidelink communication is provided, including: establishing, by a first UE, beam alignment with a second UE using a first beam in sidelink communication; receiving from the second UE a second beam-assistance indication indicating at least one of time information or frequency information associated with the second beam for the second UE for reception of signals or data from the first UE; transmitting a second beam configuration to the second UE in response to receiving the second beam-assistance indication; receiving from the second UE a confirmation of the second beam configuration; determining, by the first UE, whether selection of resources associated with use of the second beam is triggered; in response to determining that resource selection is triggered, updating a candidate resource set and selecting one or more resources from the updated candidate resource set such that the selected one or more resources are associated with use of the second beam; and transmitting one or more signals or messages using the selected one or more resources from the updated candidate resource set.

[0007] According to some embodiments of the present disclosure, a method for beam management in sidelink communication is provided. The method includes: establishing, by a second UE in sidelink communication, beam alignment with a first UE using a first beam; transmitting a second beam assistance indication to the first UE indicating at least one of time information or frequency information associated with the second beam for the second UE for reception of signals or data from the first UE; receiving a second beam configuration from the first UE in response to transmitting the second beam assistance indication; and transmitting a confirmation of the second beam configuration to the first UE.

[0008] According to some embodiments of the present disclosure, a non-transitory computer-readable medium having stored thereon instructions executable by one or more processors of a UE for performing a method for sidelink communication is provided. The method includes: establishing, by a first UE, beam alignment with a second UE using a first beam for sidelink communication; receiving from the second UE a second beam-assistance indication indicating at least one of time information or frequency information associated with the second beam for reception of signals or data from the first UE; transmitting a second beam configuration to the second UE in response to receiving the second beam-assistance indication; receiving from the second UE a confirmation of the second beam configuration; determining, by the first UE, whether selection of resources associated with use of the second beam has been triggered; updating a candidate resource set and selecting one or more resources from the updated candidate resource set in response to determining that resource selection has been triggered, such that the selected one or more resources are associated with use of the second beam; and transmitting one or more signals or messages using the selected one or more resources from the updated candidate resource set.

[0009] According to some embodiments of the present disclosure, a non-transitory computer-readable medium having stored thereon instructions executable by one or more processors of a second UE for performing a method for sidelink communication, the method including: establishing beam alignment with the first UE for sidelink communication using a first beam; transmitting a second beam assistance indication to the first UE indicating at least one of time information or frequency information associated with the second beam for the second UE for reception of signals or data from the first UE; and receiving from the first UE, in response to transmitting the second beam assistance indication: Receiving the second beam configuration and sending a confirmation of the second beam configuration to the first UE. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram illustrating a first mode for resource allocation in sidelink communications, consistent with certain embodiments of the present disclosure. [Figure 2] FIG. 10 is a schematic diagram illustrating a second mode for resource allocation in sidelink communications, consistent with some embodiments of the present disclosure. [Figure 3A] FIG. 1 is a schematic diagram illustrating a slot structure for sidelink communication. [Figure 3B] FIG. 10 is a schematic diagram illustrating another slot structure for sidelink communications consistent with certain embodiments of the present disclosure. [Figure 4] FIG. 1 is a schematic diagram illustrating a method for beam alignment between a UE and a base station consistent with certain embodiments of the present disclosure. [Figure 5] FIG. 1 is a schematic diagram illustrating a method for sidelink beam alignment between two UEs in sidelink communication, consistent with certain embodiments of the present disclosure. [Figure 6] FIG. 1 is a schematic diagram illustrating a method for configuration alignment in discontinuous reception (DRX), consistent with certain embodiments of the present disclosure. [Figure 7] 7A and 7B are schematic diagrams illustrating sidelink communication between a receiver (Rx) UE using a wide beam and two transmitter (Tx) UEs using narrow beams, consistent with some embodiments of the present disclosure. [Figure 8] FIG. 1 is a schematic diagram illustrating a method for sidelink beam alignment between two UEs in sidelink communication, consistent with certain embodiments of the present disclosure. [Figure 9] FIG. 1 is a block diagram of a UE consistent with certain embodiments of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0011] Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. The following description refers to the accompanying drawings, in which like numbers in different drawings represent the same or similar elements unless otherwise noted. The implementations set forth in the following description of exemplary embodiments do not represent all implementations consistent with the present disclosure. Rather, they are merely examples of systems, apparatus, and methods consistent with aspects related to the present disclosure as set forth in the appended claims.

[0012] FIG. 1 is a schematic diagram illustrating a first mode for resource allocation in sidelink communication consistent with some embodiments of the present disclosure. As shown with reference to FIG. 1, the communication system includes a UE 102, a UE 104, and a base station 106. The UE 102 may be a TxUE in sidelink communication (SL), and the UE 104 may be an RxUE in sidelink communication. The UE 102 and the UE 104 may be any form of UE, for example, two vehicles in V2X communication. The base station 106 may be a LTE (Long Term Evolution) The UE 102 and the UE 104 may be any currently existing base station (e.g., a gNodeB (gNB)), such as a base station for a LTE (Terminal Evolution) or New Radio (NR) or a base station for a future generation radio access technology (RAT) (sixth generation (6G), seventh generation (7G), or any other future generation). The UE 102 and the UE 104 may communicate with each other using sidelink signals. For example, the UE 102 may transmit a physical sidelink control channel (PSCCH) and / or a physical sidelink shared channel (PSSCH) to the UE 104, and in response, the UE 104 may transmit a feedback signal, such as a physical sidelink feedback channel (PSFCH), to the UE 102. The UE 102 and the UE 104 may also communicate with one or more other UEs in sidelink communications.

[0013] In a first mode for resource allocation, the UE 102 may request resources from the base station 106 when the UE 102 has data and / or signals to transmit. For example, the UE 102 may transmit a signal, such as a sidelink scheduling request (SL-SR) signal, to the base station 106. In some embodiments, the UE 102 may transmit the SL-SR via a sidelink buffer status report (SL-BSR) signal. The SL-BSR may be a medium access control (MAC) control element (CE) from the UE 102 to the base station 106 and may convey information regarding the amount of data in the UE's 102 buffer to transmit. In some embodiments, the UE 102 may transmit the SL-SR via a physical uplink control channel (PUCCH) configured for the sidelink logical channel.

[0014] Upon receiving the signal from the UE 102, the base station 106 may determine resources to be allocated to the UE 102 and transmit a signal indicating the resource allocation to the UE 102. For example, the base station 106 may grant sidelink resources for up to three transmissions of a transmission block using dynamic sidelink grant downlink control information (DCI). The base station 106 may also provide one or more configured grants allocating periodic sidelink resources to the UE 102. Similar to the UE 102, the UE 104 may also transmit a SL-SR to the base station 106, which may also perform resource allocation for the UE 104 and transmit a signal indicating the resource allocation for the UE 104.

[0015] In some embodiments, the base station 106 may configure a single resource pool across the entire spectrum, including portions unavailable for the UE 102 and / or UE 104. In some embodiments, the base station 106 may configure only one or more subchannels for the UE 102 and / or UE 104 that include one or more available physical resource blocks (PRBs).

[0016] FIG. 2 is a schematic diagram illustrating a second mode for resource allocation in sidelink communications consistent with some embodiments of the present disclosure. In the second mode for resource allocation, the UE 102 (and similarly the UE 104) may autonomously perform resource selection with the assistance of a sensing procedure. For example, the UE 102 may perform channel sensing on a configured sidelink transmission resource pool to obtain information about resources reserved by other UEs. The channel sensing may be background sensing and / or any other type of full or partial sensing. As illustrated with reference to FIG. 2, the UE 102 may perform channel sensing within a sensing window to collect resource reservation information of other UEs. For example, the UE 102 may collect resource reservation information of other UEs based on decoding sidelink control information (SCI) included in sidelink signals received from the other UEs. The UE 102 may decode the SCI based on two stages: a first stage SCI (SCI format 1-A) and a second stage SCI (SCI format 2-A or 2-B), as defined in the 3rd Generation Partnership Project (3GPP) specifications. Based on channel sensing, the UE 102 may determine candidate resources, for example, by filtering out occupied, reserved, and / or unmonitored resources. As illustrated in FIG. 2, radio resources may be divided into resources in the time domain and resources in the frequency domain. A candidate resource in the time domain may be, for example, one or more frames, subframes, slots, or symbols available for selection for the next time period. In the frequency domain, a candidate resource may be, for example, one or more channels or subchannels. FIG. 2 illustrates, for example, three available subframes or slots of a plurality of subframes or slots in the time domain. Each subframe or slot may include one or more symbols for the PSCCH and one or more symbols for the PSSCH. Resource selection (or reselection) may be performed. When a selection window is triggered, the UE 102 may select a resource from the available sidelink resources based on the channel sensing information.

[0017] In some embodiments, the UE 102 may be configured in either one of two modes (a first mode and a second mode) for resource allocation. In some embodiments, the UE 102 may be configured in both modes for resource allocation. In some embodiments, the UE 102 may switch between the first mode and the second mode for resource allocation.

[0018] 3A is a schematic diagram illustrating a slot structure 300 for sidelink communication consistent with some embodiments of the present disclosure. The slot 300 can be used for the first or second resource allocation mode described above. As shown with reference to FIG. 3A, in the time domain, the slot 300 includes 14 orthogonal frequency division multiplexing (OFDM) symbols. Of the 14 OFDM symbols, two symbols are used for demodulation reference signals (DMRS), one symbol (the first symbol) is used for automatic gain control (AGC), one symbol (the last symbol) is used for a guard period, and the remaining symbols are used for PSCCH or PSSCH. In the frequency domain, the slot 300 can include one or more subchannels, each consisting of one or more physical resource blocks (PRBs).

[0019] In some embodiments, slot 300 is used in legacy sidelink communications based on contiguous resource blocks. In this case, in the frequency domain, a resource pool may consist of a set of contiguous subchannels, with one subchannel consisting of many contiguous resource blocks. The total number of resource blocks in a given resource pool is configurable, ranging from 10 to 275. In general, sidelink resource allocation, sensing, and resource selection operations are based on subchannels. The size of the subchannels is configurable, taking values ​​of 10, 12, 15, 20, 25, 50, 75, and 100 PRBs, and the number of subchannels in a given resource pool can range from 1 to 27. As shown with reference to FIG. 3A, a PSCCH transmission is associated with the lowest subchannel of the scheduled PSSCH, indicating that the bandwidth size (in number of PRBs) of the PSCCH is always less than or equal to the size of one subchannel. PSCCH configuration is also part of resource pool configuration and can be performed, for example, by radio resource control (RRC) signaling. As an example, the PSCCH may be configured or pre-configured to occupy a certain number of PRBs in the frequency domain (e.g., 10, 12, 15, 20, or 25, <= subchannel size) and a certain number of OFDM symbols in the time domain (e.g., 2 or 3) that are set by resource pool signaling (e.g., RRC signaling) or are pre-set. The number of resources for the PSCCH in the frequency domain may be denoted as sl-FreqResourcePSCCH, and the number of resources for the PSCCH in the time domain may be denoted as sl-TimeResourcePSCCH.

[0020] FIG. 3B is a schematic diagram illustrating another slot structure 310 for sidelink communication consistent with some embodiments of the present disclosure. The slot 310 can be used for the first or second mode of resource allocation described above. As shown with reference to FIG. 3B, in the time domain, the slot 310 includes 14 OFDM symbols, of which one symbol is used for the PSFCH, two symbols are used for DMRS, two symbols are used for guard periods, one symbol is used for AGC, and the remaining symbols are used for the PSCCH or PSSCH. In the frequency domain, the slot 310 can include one or more subchannels, each consisting of one or more physical resource blocks (PRBs). As illustrated in FIG. 3B, As in slot 300, a PSCCH transmission is associated with the lowest subchannel of the scheduled PSSCH. The PSCCH configuration (e.g., DMRS, modulation and coding scheme (MCS), number of symbols used) is part of the resource pool configuration. Furthermore, information indicating which slots have PSFCH symbols is also part of the resource pool configuration. However, the PSSCH configuration (e.g., number of symbols used, DMRS pattern, and MCS) is provided by the first stage SCI, which is the payload transmitted within the PSCCH, and follows the configuration set forth in the 3GPP specifications.

[0021] FIG. 4 is a schematic diagram illustrating a method for beam alignment between a UE and a base station consistent with some embodiments of the present disclosure. The UE and base station may be connected via a Uu interface as described in 3GPP specifications. As shown with reference to FIG. 4, a method 400 for beam management between a UE and a base station (e.g., gNB, eNB) includes three phases: Phase 1, Phase 2, and Phase 3. Phase 1 includes step 402 of performing a Tx beam sweep of the base station by transmitting a synchronization signal block (SSB) from the base station. For example, the base station may generate a synchronization signal (SS) burst to transmit a synchronization signal using Tx beamforming. The SS burst may include multiple consecutive SS blocks (SSBs). The SSBs may be swept and transmitted in different angular directions covering the base station. The UE may use a wide Rx beam to receive the SSBs. The UE measures the quality of the SSBs, such as the reference signal received power (RSRP) for all SSBs on all UE panels, and selects the best SSB beam. Next, the UE transmits a physical random access channel (PRACH) on the RACH opportunity associated with the best SSB beam to connect to the base station via the reciprocal Tx beam. A correlation may be established between the UE's Rx beam associated with the best SSB beam transmitted from the base station and the corresponding UE's Tx beam. In particular, in step 404, the UE transmits a random access preamble (Message 1 or Msg1) to the base station. Msg1 is a physical layer message. In step 406, the base station transmits a random access response (RAR) (Message 2 or Msg2) to the UE in response to Msg1. Msg2 is a MAC layer message. In step 408, the UE transmits an RRC connection request or an RRC connection resumption request (Message 3 or Msg3) to the base station. Msg3 is an RRC layer request. In step 410, the base station transmits an RRC connection setup message or an RRC connection resumption message (Message 4 or Msg4) to the UE.

[0022] In Phase 2, in step 412, the base station may perform a Tx beam sweep using an improved downlink channel state information-reference signal (CSI-RS) beam within the connected SSB beam. The UE may use a wide Rx beam to receive the base station's improved downlink CSI-RS beam sweep. The UE measures the quality (e.g., RSRP) of all CSI-RS beams and reports the measurements to the base station. The UE may report the identity (ID) or beam indication of the best beam to the base station.

[0023] In Phase 3, in step 414, the base station repeatedly transmits the CSI-RS beam using the beam selected based on the UE's report in Phase 2. The UE sweeps through the refined Rx beam settings and identifies the best narrow Rx beam. At the end of Phase 3, alignment between the base station's Tx beam and the UE's Rx beam is achieved so that directional gain is maximized. In step 416, the UE may transmit one or more signals or data to the base station.

[0024] FIG. 5 illustrates a method for sidelink beam alignment between two UEs (UE-1 and UE-2) in sidelink communication, consistent with some embodiments of the present disclosure. 5 is a schematic diagram illustrating a sidelink communication system. In sidelink communication, UE-1 may be a primary UE and UE-2 may be a secondary UE. As shown with reference to FIG. 5, method 500 includes step 502 of performing a detection procedure so that UE-1 and UE-2 can recognize each other. In some embodiments, the detection procedure may be performed based on proximity-based services (ProSe) described in the 3GPP specifications. In some embodiments, the detection procedure may be performed based on Model A or Model B defined in the 3GPP specifications. In one embodiment, UE-1 and UE-2 are two UEs in a V2X system, and detection is performed at the V2X layer. In this embodiment, detection may be performed by exchanging cooperation awareness messages (CAMs) between the two UEs. The exchange of CAMs between the two UEs may occur in the 5.9 GHz Advanced Transmission System (ITS) band. In some embodiments, the detection procedure may be performed in FR1 or FR2. In this disclosure, FR1 is defined as the frequency range from 410 MHz to 7125 MHz (including the sub-6 GHz spectrum), and FR2 is defined as two frequency sub-ranges: FR2-1 from 24250 MHz to 52600 MHz and FR2-2 from 52600 MHz to 71000 MHz (including the mmWave spectrum).

[0025] The method 500 includes establishing 504 a device-to-device connection. The device-to-device connection may be a PC5 connection as described in the 3GPP specifications. For example, UE-1 and UE-2 establish a unicast link via the PC5 connection establishment. In some embodiments, the PC5 connection may be performed in FR1 or FR2.

[0026] The method 500 includes a step 506 of triggering initial beam alignment. For example, UE-1 or UE-2 may trigger the initial beam alignment. In some embodiments, the triggering of initial beam alignment may be performed in FR1 or FR2. In some embodiments, the triggering of initial beam alignment may indicate configuration details related to beam alignment. The beam alignment configuration may include at least one of a format for a sidelink-beam management reference signal (SL-BMRS) to be used in beam alignment, the number of expected beam sweeps, or a period during which the beam sweeps are expected.

[0027] After the initial beam alignment, method 500 proceeds with the beam alignment process. The beam alignment process includes three phases: Phase 1, Phase 2, and Phase 3. Phase 1 includes step 508 of performing a wide beam sweep. For example, UE-1 may perform the wide beam sweep using sequential wide Tx beams. In some embodiments, the wide beam sweep is performed in FR2. In one embodiment, each individual SL-BMRS is transmitted in a single sidelink slot. In this embodiment, if, for example, four wide beam sweeps are required, UE-1 transmits four separate sidelink slots, each with a different beam. However, the resource format for transmitting the SL-BMRS is not so limited. In some embodiments, each individual SL-BMRS is transmitted in any number of slots or symbols, depending on pre-configuration in the UE or configuration by the network (e.g., base station). UE-2 may receive the SL-BMRS using a wide Rx beam.

[0028] Phase 1 includes the step 510 of transmitting a sidelink measurement report. For example, UE-2 performs measurements on the received SL-BMRS and reports the identified best wide SL-BMRS beam to UE-1. For example, UE-2 may identify the best wide SL-BMRS beam based on the received power (maximum power) of the SL-BMRS. In some embodiments, UE-2 may report the index or slot of the best wide SL-BMRS beam to UE-1. In some embodiments, the report may include: The sidelink measurement report may be transmitted in FR1 or FR2. UE-1 may receive the sidelink measurement report using a wide Rx beam. This corresponds to the completion of Phase 1, and the method proceeds with Phase 2.

[0029] Phase 2 includes step 512 of performing a narrow beam sweep. For example, UE-1 may perform a narrow Tx SL-BMRS beam sweep. In some embodiments, UE-1 may perform a narrow SL-BMRS beam sweep in FR2. In some embodiments, the narrow Tx beam sweep utilizes a single slot per beam sweep. UE-2 may receive the narrow SL-BMRS beam using a wide Rx beam.

[0030] Phase 2 includes step 514 of transmitting sidelink measurement reports. For example, UE-2 may perform measurements on the received narrow SL-BMRS and report the identified best narrow SL-BMRS beam to UE-1. In some embodiments, UE-2 may report the index or slot of the best narrow SL-BMRS beam to UE-1. In some embodiments, the sidelink measurements may be transmitted in FR1 or FR2. UE-1 may receive the sidelink measurement report using a wide Rx beam. This corresponds to the completion of Phase 2, and method 500 proceeds to Phase 3.

[0031] Phase 3 includes step 516 of repeating beam sweeping with the selected narrow Tx beam. For example, UE-1 may perform m repetitions of the SL-BMRS sweep (m is an integer) using the selected narrow Tx beam. UE-2 may perform a narrow Rx beam sweep to identify the best narrow Rx beam. At the end of Phase 3, a beam alignment that maximizes directional gain between UE-1 and UE-2 is obtained, and UE-1 (or UE-2) may transmit signals or data.

[0032] FIG. 6 is a schematic diagram illustrating a method for configuration alignment in discontinuous reception (DRX), consistent with some embodiments of the present disclosure. As shown with reference to FIG. 6, method 600 includes step 602 of transmitting DRX assistance information. For example, the RxUE may perform sidelink beam alignment with the TxUE using method 500 of FIG. 5. The RxUE further transmits the DRX assistance information to the TxUE to inform the TxUE of the time or period when the RxUE is (or will be) awake or asleep. Upon receiving the DRX assistance information, the TxUE can determine when the TxUE should transmit a signal or data to the RxUE. For example, the TxUE may transmit a signal or data to the RxUE when the RxUE is awake. Method 600 includes step 604 of forwarding the DRX assistance information to a base station (e.g., a gNB). For example, the TxUE transmits the DRX assistance information to the base station so that the base station is aware of the DRX timing. The method 600 includes a step 606 of transmitting a DRX configuration. For example, the base station generates a DRX configuration (e.g., a resource configuration for DRX) and transmits the DRX configuration to the TxUE. The method 600 includes a step 608 of forwarding the DRX configuration to the RxUE. For example, the TxUE transmits the received DRX configuration to the RxUE. The method 600 includes a step 610 of providing a response to the DRX configuration. For example, upon receiving the DRX configuration, the RxUE may transmit an accept message or a reject message to the TxUE. When the RxUE transmits the accept message, the TxUE may transmit signals or data based on the DRX assistance information and timing in the DRX configuration and may avoid transmitting signals or data if the RxUE is in a sleep state. In this manner, power consumption in sidelink communications can be reduced.

[0033] Consistent with some embodiments of the present disclosure, FIG. 7A is a schematic diagram illustrating sidelink communication between an RxUE using a wide beam and two TxUEs using narrow beams. FIG. 7B is a schematic diagram illustrating sidelink communication between an RxUE using a narrow beam and two TxUEs using narrow beams. As shown with reference to FIG. 7A, TxUE-1 and TxUE-2 transmit signals or data to the RxUE using narrow beams, and the RxUE receives the signals or data using wide beams. The wide Rx beam used in the RxUE allows it to receive transmissions from both TxUE-1 and TxUE-2 at any time, thereby ensuring stability of sidelink communication. However, particularly in high-frequency sidelink communication, beamforming using narrow beams is required to compensate for the high path loss of high-frequency radio signals, so continuous use of the wide Rx beam may be impractical. Next, as shown with reference to FIG. 7B, TxUE-1 and TxUE-2 transmit signals or data to the RxUE using narrow beams, and the RxUE receives the transmissions using narrow Rx beams. Although a narrow Rx beam may provide advantages to an RxUE, especially in high frequency bands, the beam correspondence between the narrow Rx beam and the narrow Tx beam may be easily lost. Furthermore, a narrow Rx beam may prevent an RxUE from receiving transmissions from multiple UEs (TxUE-1 and TxUE-2) simultaneously.

[0034] At least some embodiments of the present disclosure provide a solution to the problem illustrated in FIGS. 7A-7B by employing a coordinated beam fallback mechanism, as described below. The coordinated beam fallback mechanism allows two sidelink UEs to maintain communication even when they are about to lose their beam correspondence. For example, after the TxUE and RxUE establish sidelink beam alignment using a narrow Tx beam and a narrow Rx beam, the TxUE and RxUE establish a coordination procedure regarding when the RxUE should apply a wide Rx beam, thereby enabling a beam transition in the RxUE and / or the TxUE to occur before the beam correspondence is completely lost. At least some embodiments of the present disclosure also include a biased resource selection procedure that allows the TxUE to prioritize the selection of resources on which the RxUE should apply a wide Rx beam.

[0035] FIG. 8 is a schematic diagram illustrating a method for sidelink beam alignment between two UEs (TxUE and RxUE) in sidelink communication, consistent with some embodiments of the present disclosure. As shown with reference to FIG. 8, the method 800 includes three phases: an initialization phase, a configuration phase, and an application phase. The initialization phase includes a step 802 of obtaining a sidelink configuration. The sidelink configuration can be obtained in several ways. In one embodiment, if there is no base station (e.g., gNB) in the vicinity, or if a base station is in the vicinity but does not transmit a system information block (SIB) 12, the TxUE (or RxUE) may use a sidelink configuration previously configured in the TxUE (or RxUE). In one embodiment, if the base station transmits a SIB 12, the TxUE (or RxUE) may obtain the sidelink configuration from the base station. The sidelink configuration may include information about the configuration and access parameters of the sidelink physical channel. The base station is not limited to a gNB, but can be any currently existing base station, such as a base station for LTE or NR, or a base station for a future generation (e.g., 6G, 7G), or any other future generation RAT.

[0036] The initialization phase includes step 804, in which a discovery procedure is performed between the TxUE and the RxUE, so that the two devices become aware of each other. In some embodiments, discovery is performed by the application layer of the TxUE (or the RxUE) generating an announce or discovery message that is broadcast on a sidelink physical channel. In one embodiment, for example, the application layer of the RxUE receives a decoded message from the TxUE and determines whether a unicast connection with the TxUE should be established. If the application layer of the RxUE determines that a unicast connection with the TxUE should be established, the application layer Generates a message to

[0037] The initialization phase includes step 806 of establishing a device-to-device connection. In one embodiment, the device-to-device connection is a PC5-RRC connection. For example, if the TxUE and the RxUE decide to establish a unicast connection, the PC5-RRC connection can be established. The TxUE and the RxUE may further exchange device capabilities. The device capabilities may include beamforming capabilities.

[0038] The initialization phase includes step 808 of performing beam alignment between the TxUE and the RxUE and establishing beam alignment using a first beam. For example, the TxUE and the RxUE may perform beam alignment using method 500 as illustrated in FIG. 5. After the three phases of the beam alignment procedure are completed as illustrated in FIG. 5, the TxUE and the RxUE establish beam alignment using a first beam. The first beam may be a narrow beam. The narrow beam may be a directional beam. The beamwidth of the narrow beam may be adjusted by the UE, for example, by adjusting the number of antenna elements, beamforming gain, etc. The first beam may be a high frequency beam, such as FR2.

[0039] After the initialization phase, method 800 proceeds with a configuration phase. The configuration phase includes step 810 of receiving (transmitting) a second beam-assistance indication. For example, the RxUE transmits a second beam-assistance indication to the TxUE, and the TxUE receives the transmitted second beam-assistance indication. In some embodiments, the second beam may be a wide beam (e.g., at least wider than the first beam). The beamwidth of the wide beam may be adjusted by the RxUE (or the TxUE), for example, by adjusting the number of antenna elements, beamforming gain, etc. In some embodiments, the second beam is FR1 or FR2. In some embodiments, the RxUE generates the second beam-assistance indication based on at least one of one or more channel busy ratio (CBR) ranges, an absolute rate range of the TxUE, an absolute rate range of the RxUE, a relative rate range between the TxUE and the RxUE, or priority information of one or more packets transmitted from the TxUE. The absolute velocity range of the TxUE, the absolute velocity range of the RxUE, and the range of relative velocities between the TxUE and the RxUE may be determined based on an exchange of absolute velocities and orientations of the TxUE and the RxUE. In some embodiments, the second beam-assistance indication may indicate at least one of time information or frequency information associated with a second beam for the RxUE for receiving signals or data from the TxUE. For example, the time information or frequency information may include a time or frequency that the RxUE wants to use to utilize the second beam as a new Rx beam for receiving signals or data from the TxUE. In some embodiments, the second beam-assistance indication includes assistance information for using the second beam as a second receive beam at the RxUE, wherein the assistance information includes at least one of a periodicity of the second receive beam, an offset of the second receive beam, a duration of the second receive beam, one or more frequency resources, an orientation of the receive panel, or a receive beam width.

[0040] The configuration phase includes step 812 of transmitting (or receiving) a second beam configuration. For example, the TxUE generates a second beam configuration in response to receiving a second beam-assistance indication, transmits the second beam configuration to the RxUE, and the RxUE receives the second beam configuration. In some embodiments, the TxUE generates the second beam configuration based on one or more scheduling constraints of the TxUE. The one or more scheduling constraints of the TxUE may include at least one of a receive beam fallback configuration with a third UE that causes a receive beam fallback from the second beam, or an existing discontinuous reception configuration that needs to be maintained at the TxUE. In some embodiments, the second beam configuration is The configuration includes second receive beam configuration information for a second receive beam to be used by the RxUE. The second receive beam configuration information may include at least one of a periodicity of the second receive beam, an offset of the second receive beam, a duration of the second receive beam, one or more frequency resources, an orientation of the receive panel, a receive beam width, acceptance of the configuration included in the second beam-assistance instruction, or rejection of the configuration included in the second beam-assistance instruction.

[0041] The configuration phase includes step 814 of receiving (or transmitting) a confirmation of the second beam configuration. For example, after transmitting the second beam configuration, the TxUE may receive a confirmation of the second beam configuration from the RxUE. In some embodiments, the confirmation of the second beam configuration is received via RRC signaling, MAC CE, or physical layer signaling. The physical layer signaling may include at least one of a hybrid automatic repeat request (HARQ), an SCI, or a PSFCH.

[0042] After the configuration phase, method 800 proceeds with an application phase. The application phase includes step 816 of determining whether resource selection has been triggered, the resource selection being associated with the use of a second beam. For example, upon receiving confirmation of the second beam configuration from the RxUE, the TxUE may determine whether resource selection has been triggered. In some embodiments, the trigger for resource selection includes at least one of: (a) receipt of a negative acknowledgment (NACK) message or no HARQ feedback in response to transmission of a transmission block; (b) receipt of a NACK message or no HARQ feedback in response to a retransmission of a transmission block; (c) a decrease in one or more signal parameters, including at least one of a signal-to-interference-and-noise ratio (SINR), RSRP, or reference signal strength indicator (RSSI), below a first threshold; (d) a decrease in one or more signal parameters, including at least one of a SINR, RSRP, or RSSI, from a previous state to a current state exceeding a second threshold; or (e) no receipt of a scheduled transmission.

[0043] The application phase includes step 818 of updating a candidate resource set and selecting one or more resources from the updated candidate resource set if resource selection is triggered. For example, in response to determining that resource selection is triggered, the TxUE may update the candidate resource set and select one or more resources from the updated candidate resource set, such that the selected one or more resources are associated with use of the second beam. The candidate resource set may be any candidate resource set previously determined by the TxUE. In some embodiments, updating the candidate resource set includes excluding one or more resources not associated with use of the second beam from the candidate resource set to form a new candidate resource set. After updating, the new candidate resource set is associated with use of the second beam. For example, the new candidate resource set may include only resources associated with use of the second beam. In some embodiments, the second beam is a wide beam, and resources that do not include wide Rx beam resources are excluded from the previous candidate resource set. In this manner, the TxUE and RxUE can switch between the first beam and the second beam using the fallback mechanism described above.

[0044] The application phase includes a step 820 of transmitting (or receiving) one or more signals or messages using one or more resources selected from the updated candidate resource set. For example, the TxUE may transmit one or more signals or messages to the RxUE using one or more resources selected from the new candidate resource set. In some embodiments, the one or more signals or messages include at least one of a beam realignment request, a receive beam realignment request, a receive beam resource, or a reception of a PSFCH.

[0045] By switching between a first beam (e.g., a narrow beam) and a second beam (e.g., a wide beam), beam gain is achieved compared to a system using only a single beam (the first beam or the second beam). In addition, the TxUE and RxUE have a fallback mechanism, which allows for faster beam realignment when communication via the first beam (e.g., a narrow beam) is about to fail, improving reliability and efficiency in sidelink communication.

[0046] The methods described in this disclosure may be applied to any sidelink communication, such as, for example, LTE or NR or future generation (e.g., 6G, 7G, or any future generation) sidelink communication. The methods described in this disclosure may also be applied to sidelink communication involving any number of UEs. The methods described in this disclosure may also be applied to downlink / uplink communication between a base station and a UE. The methods described in this disclosure may also be applied to other systems, for example, systems conforming to other standards (e.g., Institute of Electrical and Electronics Engineers (IEEE) standards), such as IEEE 802.11 technology.

[0047] Figure 9 is a block diagram of a UE 900 consistent with some embodiments of the present disclosure. For example, the UE 900 may be the TxUE or RxUE of Figure 8 and perform the method of Figure 8. The UE 900 may be mounted in a moving vehicle or at a fixed location. The UE 900 may take any form, including, but not limited to, a vehicle, a vehicle-mounted component, a roadside unit, a laptop computer, a wireless terminal including a mobile phone, a wireless handheld device, or a wireless personal device, or any other form.

[0048] As shown with reference to FIG. 9, a UE 900 may include an antenna 902 that may be used for transmitting and receiving electromagnetic signals to and from a base station or other UEs. The antenna 902 may include one or more antenna elements and may enable different input / output antenna configurations, such as, for example, a multiple-input multiple-output (MIMO) configuration, a multiple-input single-output (MISO) configuration, and a single-input multiple-output (SIMO) configuration. In some embodiments, the antenna 902 may include multiple (e.g., tens or hundreds) antenna elements and may enable multi-antenna functions such as beamforming. In some embodiments, the antenna 902 is a single antenna. In some embodiments, the antenna 902 may provide wide and narrow beams and may be able to switch between the wide and narrow beams as needed, as described in FIGS. 5 and 8.

[0049] The UE 900 may include a transceiver 904 coupled to an antenna 902. The transceiver 904 may be a wireless transceiver in the UE 900 and may communicate bidirectionally with a base station or other UEs. For example, the transceiver 904 may receive / transmit wireless signals to / from a base station via downlink / uplink communication. The transceiver 904 may also receive / transmit wireless signals to / from another UE or a roadside unit via sidelink communication. The transceiver 904 may include a modem for modulating packets and providing the modulated packets to the antenna 902 for transmission and for demodulating packets received from the antenna 902.

[0050] The UE 900 may include a memory 906. The memory 906 may be any type of computer-readable storage medium, including volatile or non-volatile memory devices, or a combination thereof. Computer-readable storage media include, but are not limited to, non-transitory computer storage media. Non-transitory storage media may be accessed by a general-purpose computer or a special-purpose computer. Examples of non-transitory storage media include portable computer diskettes, hard disks, random access memory (RAM), read-only memory (ROM), and the like. Non-transitory media include, but are not limited to, erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), digital versatile disk (DVD), flash memory, compact disk (CD) ROM, or other optical disk storage, magnetic disk storage, or other magnetic storage devices. Non-transitory media may be used to carry or store desired program code means (e.g., instructions and / or data structures) and may be accessed by a general-purpose computer or a special-purpose computer or processor. In some examples, software / program code may be transmitted from a remote source (e.g., a website, a server, etc.) using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, microwave, etc. In such examples, coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, microwave, etc. are included within the definition of medium. Combinations of the above examples are also within the scope of computer-readable media.

[0051] The memory 906 may store identification information of the UE 900 and information regarding signals and / or data received by the antenna 902. The memory 906 may also store post-processed signals and / or data. The memory 906 may also store computer-readable program instructions, mathematical models, and algorithms used for signal processing in the receiver 904 and calculations in the processor 908. The memory 906 may further store computer-readable program instructions for execution by the processor 908 to operate the UE 900 to perform various functions described in this disclosure. In some examples, the memory 906 may include a basic input / output system (BIOS) that may control basic hardware or software operations, such as interactions with peripheral components or devices.

[0052] The computer-readable program instructions of the present disclosure may be assembler instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, state-setting data, or source or object code written in any combination of one or more programming languages, including object-oriented programming languages ​​and conventional procedural programming languages. The computer-readable program instructions may execute as a standalone software package, entirely on a computing device, or partially on a first computing device and partially on a second computing device remote from the first computing device. In the latter scenario, the second, remote computing device may be connected to the first computing device via any type of network, including a local area network (LAN) or a wide area network (WAN).

[0053] The UE 900 may include a processor 908, which may include hardware devices with processing capabilities. The processor 908 may include at least one of a general-purpose processor, a digital signal processor (DSP), a central processing unit (CPU), a microcontroller, an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or other programmable logic device. Examples of a general-purpose processor include, but are not limited to, a microprocessor, any conventional processor, controller, microcontroller, or state machine. In some embodiments, the processor 908 may be implemented using a combination of devices (e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or other such configuration). The processor 908 may receive downlink or sidelink signals from the transceiver 904 and further process those signals. The processor 908 also receives data packets from the transceiver 904. The processor 908 may receive packets and further process those packets. In some embodiments, the processor 908 may be configured to operate the memory using a memory controller. In some embodiments, the memory controller may be integrated into the processor 908. The processor 908 may be configured to execute computer-readable instructions stored in a memory (e.g., memory 906) to cause the UE 900 to perform various functions.

[0054] The UE 900 may include a global positioning system (GPS) 910. The GPS 910 may be used to enable location-based services or other services based on the geographic location of the UE 900 and / or synchronization between UEs. The GPS 910 may receive a global navigation satellite system (GNSS) signal from a single satellite or multiple satellite signals via the antenna 902 and provide the geographic location of the UE 900 (e.g., the coordinates of the UE 900). In some embodiments, the GPS 910 is omitted. In some embodiments, a timer is included.

[0055] The UE 900 may include input / output (I / O) devices 912 that can be used to communicate the results of signal processing and calculations to a user or another device. The I / O devices 912 may include a user interface including a display and an input device for sending user commands to the processor 908. The display may be configured to display the status of signal reception in the UE 900, data stored in the memory 906, the status of signal processing, and the results of calculations. The display may include, but is not limited to, a cathode ray tube (CRT), a liquid crystal display (LCD), a light emitting diode (LED), a gas plasma display, a touchscreen, or other image projection device for displaying information to a user. The input devices may be any type of computer hardware equipment used to receive data and control signals from a user. The input devices may include, but are not limited to, a keyboard, a mouse, a scanner, a digital camera, a joystick, a trackball, cursor direction keys, a touchscreen monitor, or an audio / video commander.

[0056] The UE 900 may further include a machine interface 914, such as an electrical bus, that connects the transceiver 904, the memory 906, the processor 908, the GPS 910, and the I / O device 912.

[0057] In some embodiments, the UE 900 may be a first UE (e.g., a TxUE as illustrated in FIG. 8) in sidelink communication. The processor 908 may be configured or programmed to execute instructions stored in the memory 906 to establish beam alignment with a second UE (e.g., an RxUE as illustrated in FIG. 8) using a first beam, receive a second beam-assistance indication from the second UE indicating at least one of time information or frequency information associated with the second beam for the second UE for reception of signals or data from the first UE, transmit a second beam configuration to the second UE in response to receiving the second beam-assistance indication, receive a confirmation of the second beam configuration from the second UE, determine whether selection of resources associated with use of the second beam has been triggered, and in response to determining that resource selection has been triggered, update a candidate resource set, select one or more resources from the updated candidate resource set such that the selected one or more resources are associated with use of the second beam, and transmit one or more signals or messages using the selected one or more resources from the updated candidate resource set.

[0058] In some embodiments, the UE 900 may be a second UE in sidelink communication (e.g., an Rx UE as illustrated in FIG. 8). The processor 908 executes instructions stored in the memory 906 to communicate with the first UE (e.g., an Rx UE as illustrated in FIG. 8) using the first beam. TxUE as shown in FIG. 1 ; transmit a second beam-assistance indication to the first UE indicating at least one of time information or frequency information associated with the second beam for the second UE for reception of signals or data from the first UE; receive a second beam configuration from the first UE in response to transmitting the second beam-assistance indication; and transmit a confirmation of the second beam configuration to the first UE.

[0059] As used in this disclosure, the use of the word "or" in a list of items indicates an inclusive list. A list of items may begin with phrases such as "at least one of" or "one or more of." For example, a list of at least one of A, B, or C includes A or B or C or AB (i.e., A and B), or AC or BC or ABC (i.e., A and B and C). Also, as used in this disclosure, the phrase "based on" preceding a list of conditions shall not be construed as "based only on" the set of conditions, but as "based at least in part on" the set of conditions. For example, a result described as "based on condition A" may be based on both condition A and condition B without departing from the scope of this disclosure.

[0060] As used herein, the terms "comprise," "include," or "contain" can be used interchangeably, have the same meaning, and are to be construed as inclusive and open-ended. The terms "comprise," "include," or "contain" can be used before a list of elements to indicate that at least all of the listed elements are present in the list, but that other elements not included in the list may also be present. For example, if A comprises B and C, then both {B,C} and {B,C,D} are within the scope of A.

[0061] The present disclosure, in connection with the accompanying drawings, describes exemplary configurations, which do not represent all examples that may be implemented or all configurations within the scope of the present disclosure. The term "exemplary" should not be interpreted as "preferred" or "advantageous over other examples," but rather as "an example, instance, or example." Upon reading this disclosure, including the description of the embodiments and the drawings, those skilled in the art will recognize that the techniques disclosed herein may be implemented using alternative embodiments. Those skilled in the art will recognize that the embodiments described herein, or specific features of the embodiments, may be combined to obtain yet other embodiments for practicing the techniques described in the present disclosure. Thus, the present disclosure is not limited to the examples and designs described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0062] The flowcharts and block diagrams in the figures illustrate examples of the architecture, functionality, and operation of possible implementations of systems, methods, and devices according to various embodiments. It should be noted that in some alternative implementations, the functions noted in the blocks may differ from the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently or may be executed in the reverse order, depending on the functionality involved. Similarly, additional steps may be included in such methods, and certain steps may be omitted or combined, in methods consistent with various embodiments.

[0063] It is understood that the described embodiments are not mutually exclusive, and that elements, components, materials, or steps described in connection with one exemplary embodiment may be combined with or excluded from other embodiments in any suitable manner to achieve desired design objectives.

[0064] References herein to "some embodiments" or "some exemplary embodiments" mean that a particular feature, structure, or characteristic described in connection with an embodiment can be included in at least one embodiment. The appearances of the phrases "one embodiment," "some embodiments," or "another embodiment" in various places in this disclosure do not necessarily all refer to the same embodiments, nor are separate or alternative embodiments necessarily mutually exclusive of other embodiments.

[0065] Additionally, the articles "a" and "an," as used in this disclosure and the appended claims, should generally be construed to mean "one or more," unless otherwise specified or unless the context makes clear a reference to the singular form.

[0066] Unless expressly stated otherwise, each numerical value and range should be interpreted as being approximate, as if the word "about" or "approximately" were added before the value or range value.

[0067] Although elements in the following method claims, if any, are recited in a particular sequence, unless the claim recitation implies a particular sequence for performing some or all of the elements, the elements are not necessarily intended to be limited to being performed in that particular sequence.

[0068] It will also be appreciated that certain features of the present disclosure, which are described for clarity in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features herein, which are described for brevity in the context of a single embodiment, may also be provided individually or in any suitable subcombination, or as needed, in any other embodiment described herein. Certain features described in the context of various embodiments are not essential features of those embodiments, unless specifically noted.

[0069] Furthermore, it will be understood that various changes, substitutions, and variations may be made by those skilled in the art in the details, materials, and arrangements of parts described and illustrated to explain the nature of the described embodiments without departing from the scope thereof, and therefore the following claims encompass all such alternatives, modifications, and variations within the terms of the claims.

[0070] Item 1: A first user equipment (UE) for sidelink communication, a memory for storing instructions; Executes instructions stored in memory establishing beam alignment with a second UE using the first beam; receiving a second beam assistance indication from the second UE indicating at least one of time information or frequency information associated with a second beam for the second UE for reception of signals or data from the first UE; In response to receiving the second beam assistance indication, transmitting a second beam configuration to the second UE; receiving a confirmation of the second beam configuration from the second UE; determining whether a selection of a resource associated with use of the second beam has been triggered; In response to determining that resource selection is triggered, updating the candidate resource set and selecting one or more resources from the updated candidate resource set such that the selected one or more resources are associated with use of the second beam; and a processor configured to transmit one or more signals or messages using one or more resources selected from the updated candidate resource set.

[0071] Clause 2: In the first UE according to clause 1, when updating the candidate resource set, the processor further executes instructions to: The method is configured to exclude one or more resources that are not associated with use of the second beam from the candidate resource set to form a new candidate resource set.

[0072] Clause 3: The first UE of clause 2, wherein the new candidate resource set is associated with the use of a second beam.

[0073] Clause 4: The first UE of clause 1, wherein the second beam is wider than the first beam.

[0074] Clause 5: A first UE as described in clause 1, wherein the second beam assistance instruction comprises assistance information for using the second beam as a second receive beam, and the assistance information includes at least one of a periodicity of the second receive beam, an offset of the second receive beam, a duration of the second receive beam, one or more frequency resources, an orientation of the receive panel, or a receive beam width.

[0075] Clause 6: The first UE of clause 1, wherein the processor further executes instructions to: and configured to generate the second beam configuration based on one or more scheduling constraints of the first UE.

[0076] Clause 7: The first UE according to clause 6, wherein the one or more scheduling constraints of the first UE are: a receive beam fallback configuration with a third UE causing a receive beam fallback from the second beam; or At least one of the existing discontinuous reception configurations needs to be maintained.

[0077] Clause 8: The first UE of clause 1, wherein the second beam configuration comprises second receive beam configuration information, and the second receive beam configuration information includes at least one of a periodicity of the second receive beam, an offset of the second receive beam, a duration of the second receive beam, one or more frequency resources, an orientation of the receive panel, a receive beam width, acceptance of the configuration included in the second beam assistance instruction, or rejection of the configuration included in the second beam assistance instruction.

[0078] Clause 9: The first UE of clause 1, wherein the confirmation of the second beam configuration is transmitted via radio resource control (RRC) signaling, a medium access control (MAC) control element (CE), or physical layer signaling.

[0079] Clause 10: The first UE described in clause 9, wherein the physical layer signaling comprises at least one of hybrid automatic repeat request (HARQ), sidelink control information (SCI), or a physical sidelink feedback channel (PSFCH).

[0080] Clause 11: The first UE according to clause 1, wherein the trigger for selecting the resource is: (a) receiving a negative acknowledgement (NACK) message in response to sending a transmission block or not receiving HARQ feedback; (b) receiving a NACK message or not receiving HARQ feedback in response to a retransmission of a transmission block; (c) a decrease in one or more signal parameters, including at least one of a signal-to-interference-and-noise ratio (SINR), a reference signal received power (RSRP), or a reference signal strength indicator (RSSI), below a first threshold; (d) one or more of SINR, RSRP, or RSSI; a decrease in the plurality of signal parameters from a previous state to a current state exceeding a second threshold; or (e) non-reception of a scheduled transmission.

[0081] Clause 12: The first UE of clause 1, wherein the one or more signals or messages comprise at least one of a beam realignment request, a receive beam realignment request, a receive beam resource, or a reception of a PSFCH.

[0082] Clause 13: In the first UE of clause 1, when establishing beam alignment with the second UE using the first beam, the processor further executes instructions to: The UE is configured to obtain a sidelink configuration or a sidelink preconfiguration from the network, detect the second UE using a detection message, establish a unicast connection with the second UE, and perform a beam alignment procedure to establish beam alignment with the second UE using the first beam.

[0083] Clause 14: The first UE according to clause 1, wherein in the sidelink communication, the first UE is a transmitter UE and the second UE is a receiver UE.

[0084] Clause 15: The first UE of clause 1, wherein the first beam is FR2 and the second beam is FR1 or FR2.

[0085] Clause 16: A second user equipment (UE) for sidelink communication, a memory for storing instructions; Executes instructions stored in memory establishing beam alignment with the first UE using the first beam; transmitting a second beam assistance indication to the first UE indicating at least one of time information or frequency information associated with a second beam for the second UE for reception of signals or data from the first UE; receiving a second beam configuration from the first UE in response to transmitting the second beam assistance indication; and a processor configured to send a confirmation of the second beam configuration to the first UE.

[0086] Clause 17: The second UE of clause 16, wherein the second beam is wider than the first beam.

[0087] Clause 18: A second UE as described in clause 16, wherein the second beam assistance indication is generated based on at least one of one or more channel busy ratio (CBR) ranges, an absolute speed range of the first UE, an absolute speed range of the second UE, a relative speed range between the first UE and the second UE, or priority information of one or more packets transmitted from the first UE.

[0088] Clause 19: A second UE as described in clause 18, wherein the absolute velocity range of the first UE, the absolute velocity range of the second UE, and the range of relative velocity between the first UE and the second UE are determined based on an exchange of absolute velocities and orientations of the first UE and the second UE.

[0089] Clause 20: A method for beam management in sidelink communications, comprising: establishing, by a first UE, beam alignment with a second UE using a first beam in sidelink communication; a second beam indicating at least one of time information or frequency information associated with the second beam for the second UE for receiving signals or data from the first UE; receiving an assistance indication from the second UE; In response to receiving the second beam assistance indication, transmitting a second beam configuration to the second UE; receiving a confirmation of the second beam configuration from the second UE; determining, by the first UE, whether selection of resources associated with use of the second beam has been triggered; In response to determining that resource selection is triggered, updating a candidate resource set and selecting one or more resources from the updated candidate resource set such that the selected one or more resources are associated with use of the second beam; and transmitting one or more signals or messages using one or more resources selected from the updated candidate resource set.

[0090] Clause 21: The method of clause 20, wherein updating the candidate resource set further comprises: The method includes excluding one or more resources from the candidate resource set that are not associated with use of the second beam to form a new candidate resource set.

[0091] Clause 22: The method of clause 21, wherein the new candidate resource set is associated with the use of a second beam.

[0092] Clause 23: The method of clause 20, wherein the second beam is wider than the first beam.

[0093] Clause 24: The method described in clause 20, wherein the second beam assistance instruction comprises assistance information for using the second beam as a second receive beam, and the assistance information includes at least one of a periodicity of the second receive beam, an offset of the second receive beam, a duration of the second receive beam, one or more frequency resources, an orientation of the receive panel, or a receive beam width.

[0094] Item 25: A method according to item 20, comprising: Further includes generating a second beam configuration based on one or more scheduling constraints of the first UE.

[0095] Clause 26: The method of clause 25, wherein the one or more scheduling constraints of the first UE include: a receive beam fallback configuration with a third UE causing a receive beam fallback from the second beam; or At least one of the existing discontinuous reception configurations needs to be maintained.

[0096] Clause 27: The method of clause 20, wherein the second beam configuration comprises second receive beam configuration information, and the second receive beam configuration information includes at least one of a periodicity of the second receive beam, an offset of the second receive beam, a duration of the second receive beam, one or more frequency resources, an orientation of the receive panel, a receive beam width, acceptance of the configuration included in the second beam assistance instruction, or rejection of the configuration included in the second beam assistance instruction.

[0097] Clause 28: A method as described in clause 20, wherein confirmation of the second beam configuration is transmitted via radio resource control (RRC) signaling, medium access control (MAC) control element (CE) signaling, or physical layer signaling.

[0098] Clause 29: The method according to clause 28, wherein the physical layer signaling is a hybrid automatic It comprises at least one of a repeat request (HARQ), a sidelink control information (SCI), or a physical sidelink feedback channel (PSFCH).

[0099] Clause 30: The method according to clause 20, wherein the trigger for the selection of a resource is: (a) receiving a negative acknowledgement (NACK) message in response to sending a transmission block or not receiving HARQ feedback; (b) receiving a NACK message or not receiving HARQ feedback in response to a retransmission of a transmission block; (c) a decrease in one or more signal parameters, including at least one of a signal-to-interference-and-noise ratio (SINR), a reference signal received power (RSRP), or a reference signal strength indicator (RSSI), below a first threshold; (d) a decrease in one or more signal parameters, including at least one of SINR, RSRP, or RSSI, from a previous state to a current state exceeds a second threshold; or (e) non-reception of a scheduled transmission.

[0100] Clause 31: The method of clause 20, wherein the one or more signals or messages comprise at least one of a beam realignment request, a receive beam realignment request, a receive beam resource, or receiving a PSFCH.

[0101] Clause 32: The method of clause 20, wherein establishing beam alignment with the second UE using the first beam further comprises: obtaining a sidelink configuration or a sidelink preconfiguration from the network; Detecting a second UE using the detection message; establishing a unicast connection with a second UE; and performing a beam alignment procedure to establish beam alignment with the second UE using the first beam.

[0102] Clause 33: The method according to clause 20, wherein in the sidelink communication, the first UE is a transmitter UE and the second UE is a receiver UE.

[0103] Clause 34: The method according to clause 20, wherein the first beam is FR2 and the second beam is FR1 or FR2.

[0104] Clause 35: A method for beam management in sidelink communications, comprising: establishing, by a second user equipment (UE), beam alignment with the first UE using the first beam in sidelink communication; transmitting a second beam assistance indication to the first UE indicating at least one of time information or frequency information associated with a second beam for the second UE for reception of signals or data from the first UE; receiving a second beam configuration from the first UE in response to transmitting the second beam assistance indication; and transmitting a confirmation of the second beam configuration to the first UE.

[0105] Clause 36: A method according to clause 35, wherein the second beam assistance instruction is generated based on at least one of one or more channel busy ratio (CBR) ranges, an absolute speed range of the first UE, an absolute speed range of the second UE, a relative speed range between the first UE and the second UE, or priority information of one or more packets transmitted from the first UE.

[0106] Clause 37: The method described in clause 36, wherein the absolute velocity range of the first UE, the absolute velocity range of the second UE, and the range of relative velocities between the first UE and the second UE are determined based on exchanging the absolute velocities and orientations of the first UE and the second UE using the first beam.

[0107] Clause 38: A non-transitory computer-readable medium storing instructions executable by one or more processors of a first user equipment (UE) for sidelink communication to perform a method, the method comprising: establishing, by the first UE, beam alignment with the second UE for sidelink communication using the first beam; receiving a second beam assistance indication from the second UE indicating at least one of time information or frequency information associated with a second beam for the second UE for reception of signals or data from the first UE; In response to receiving the second beam assistance indication, transmitting a second beam configuration to the second UE; receiving a confirmation of the second beam configuration from the second UE; determining, by the first UE, whether selection of resources associated with use of the second beam has been triggered; In response to determining that resource selection is triggered, updating a candidate resource set and selecting one or more resources from the updated candidate resource set such that the selected one or more resources are associated with use of the second beam; and transmitting one or more signals or messages using one or more resources selected from the updated candidate resource set.

[0108] Clause 39: A non-transitory computer-readable medium storing instructions executable by one or more processors of a second user equipment (UE) for sidelink communication to perform a method, the method comprising: establishing beam alignment with a first UE for sidelink communication using the first beam; transmitting a second beam assistance indication to the first UE indicating at least one of time information or frequency information associated with a second beam for the second UE for reception of signals or data from the first UE; receiving a second beam configuration from the first UE in response to transmitting the second beam assistance indication; and transmitting a confirmation of the second beam configuration to the first UE.

Claims

1. A first user equipment (UE) for sidelink communication, comprising: a memory for storing instructions; Executing the instructions stored in the memory, establishing beam alignment with a second UE using the first beam; receiving a second beam assistance indication from the second UE indicating at least one of time information or frequency information associated with a second beam for the second UE for reception of signals or data from the first UE; In response to receiving the second beam assistance indication, transmitting a second beam configuration to the second UE; receiving a confirmation of the second beam configuration from the second UE; determining whether a selection of resources associated with use of the second beam has been triggered; In response to determining that the selection of the resource is triggered, updating a candidate resource set and selecting one or more resources from the updated candidate resource set such that the selected one or more resources are associated with the use of the second beam; Transmitting one or more signals or messages using the one or more resources selected from the updated set of candidate resources. and a processor configured to:

2. When updating the candidate resource set, the processor further executes the instructions to: excluding from the candidate resource set one or more resources that are not associated with the use of the second beam to form a new candidate resource set. The first UE of claim 1 , configured to:

3. the second beam is wider than the first beam; The first UE of claim 1 .

4. the second beam assistance instruction comprises assistance information for using the second beam as a second receive beam, the assistance information including at least one of a periodicity of the second receive beam, an offset of the second receive beam, a duration of the second receive beam, one or more frequency resources, an orientation of a receive panel, or a receive beam width; The first UE of claim 1 .

5. The processor further executes the instructions to: generating the second beam configuration based on one or more scheduling constraints of the first UE; The first UE of claim 1 , configured to:

6. The one or more scheduling constraints of the first UE: a receive beam fallback configuration with a third UE causing a receive beam fallback from the second beam; or at least one of the existing discontinuous reception configurations that needs to be maintained; The first UE of claim 1 .

7. The second beam configuration comprises second receive beam configuration information, and the second receive beam configuration information includes a periodicity of the second receive beam, an offset of the second receive beam, the second beam-assistance instruction includes at least one of a duration of the second receive beam, one or more frequency resources, an orientation of the receive panel, a receive beam width, acceptance of the configuration included in the second beam-assistance instruction, or rejection of the configuration included in the second beam-assistance instruction; The first UE of claim 1 .

8. the confirmation of the second beam configuration is sent via Radio Resource Control (RRC) signaling, Medium Access Control (MAC) Control Element (CE) signaling, or Physical Layer signaling. The first UE of claim 1 .

9. The trigger for the selection of the resource comprises: (a) Receipt of a negative acknowledgement (NACK) message or non-reception of HARQ feedback in response to transmission of a transmission block; (b) receiving a NACK message or not receiving HARQ feedback in response to a retransmission of the transmission block; (c) a decrease in one or more signal parameters, including at least one of a signal-to-interference-and-noise ratio (SINR), a reference signal received power (RSRP), or a reference signal strength indicator (RSSI), below a first threshold; (d) a decrease in one or more signal parameters, including at least one of SINR, RSRP, or RSSI, from a previous state to a current state exceeds a second threshold; or Missed scheduled transmission The first UE of claim 1 , comprising at least one of:

10. the one or more signals or messages comprise at least one of a beam realignment request, a receive beam realignment request, a receive beam resource, or a reception of a PSFCH. The first UE of claim 1 .

11. When establishing the beam alignment with the second UE using the first beam, the processor further executes the instructions to: Get Sidelink configuration from the network or Sidelink pre-configuration, Detecting the second UE using a detection message; establishing a unicast connection with the second UE; performing a beam alignment procedure to establish the beam alignment with the second UE using the first beam; The first UE of claim 1 , configured to:

12. a second user equipment (UE) for sidelink communication, a memory for storing instructions; Executing the instructions stored in the memory, establishing beam alignment with the first UE using the first beam; transmitting a second beam assistance indication to the first UE indicating at least one of time information or frequency information associated with a second beam for the second UE for reception of signals or data from the first UE; receiving a second beam configuration from the first UE in response to the transmission of the second beam assistance indication; sending a confirmation of the second beam configuration to the first UE; and a processor configured to:

13. The second UE of claim 12 , wherein the second beam is wider than the first beam.

14. The second UE of claim 12, wherein the second beam assistance indication is generated based on at least one of one or more channel busy ratio (CBR) ranges, an absolute speed range of the first UE, an absolute speed range of the second UE, a relative speed range between the first UE and the second UE, or priority information of one or more packets transmitted from the first UE.

15. the absolute velocity range of the first UE, the absolute velocity range of the second UE, and the range of the relative velocity between the first UE and the second UE are determined based on an exchange of absolute velocities and headings of the first UE and the second UE; The second UE of claim 14.

16. 1. A method for beam management in sidelink communication, comprising: establishing, by a first UE, beam alignment with a second UE using a first beam in the sidelink communication; receiving a second beam assistance indication from the second UE indicating at least one of time information or frequency information associated with a second beam for the second UE for reception of signals or data from the first UE; In response to receiving the second beam assistance indication, transmitting a second beam configuration to the second UE; receiving a confirmation of the second beam configuration from the second UE; determining, by the first UE, whether selection of resources associated with use of the second beam has been triggered; In response to determining that the selection of the resource is triggered, updating a candidate resource set and selecting one or more resources from the updated candidate resource set such that the selected one or more resources are associated with the use of the second beam; transmitting one or more signals or messages using the one or more resources selected from the updated candidate resource set. method.

17. Updating the candidate resource set further comprises: excluding from the candidate resource set one or more resources that are not associated with the use of the second beam to form a new candidate resource set.

17. The method of claim 16.

18. 1. A method for beam management in sidelink communication, comprising: establishing, by a second user equipment (UE) in the sidelink communication, beam alignment with the first UE using the first beam; transmitting a second beam assistance indication to the first UE indicating at least one of time information or frequency information associated with a second beam for the second UE for reception of signals or data from the first UE; receiving a second beam configuration from the first UE in response to the transmission of the second beam assistance indication; transmitting a confirmation of the second beam configuration to the first UE. method.

19. a non-transitory computer-readable storage medium storing instructions executable by one or more processors of a first user equipment (UE) for sidelink communication to perform a method; A medium, the method comprising: establishing, by the first UE, beam alignment with a second UE for the sidelink communication using a first beam; receiving a second beam assistance indication from the second UE indicating at least one of time information or frequency information associated with a second beam for the second UE for reception of signals or data from the first UE; In response to receiving the second beam assistance indication, transmitting a second beam configuration to the second UE; receiving a confirmation of the second beam configuration from the second UE; determining, by the first UE, whether selection of resources associated with use of the second beam has been triggered; In response to determining that the selection of the resource is triggered, updating a candidate resource set and selecting one or more resources from the updated candidate resource set such that the selected one or more resources are associated with the use of the second beam; transmitting one or more signals or messages using the one or more resources selected from the updated candidate resource set. Non-transitory computer-readable medium.

20. 1. A non-transitory computer-readable medium storing instructions executable by one or more processors of a second user equipment (UE) for sidelink communication to perform a method, the method comprising: establishing beam alignment with a first UE for the sidelink communication using a first beam; and transmitting a second beam assistance indication to the first UE indicating at least one of time information or frequency information associated with a second beam for the second UE for reception of signals or data from the first UE; receiving a second beam configuration from the first UE in response to the transmission of the second beam assistance indication; transmitting a confirmation of the second beam configuration to the first UE. Non-transitory computer-readable medium.

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