Sidelink beam alignment by UE-to-UE coordination

Abstract

The method includes receiving, by a first UE in sidelink communication, an Inter-UE Coordination (IUC) signal transmitted from a second UE; determining a set of candidate radio resources for communication with the second UE based on the IUC signal; determining at least one direction associated with the IUC signal based on an estimated angle of arrival of the IUC signal; selecting at least one beam for communication with the second UE from among a plurality of beams based on at least one of the determined at least one direction or content of the IUC signal; determining a subset of radio resources from the set of candidate radio resources based on sensing on the selected at least one beam; and transmitting the determined subset of radio resources to the second UE or selecting one or more radio resources for communication with the second UE from the determined subset of radio resources.

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED PATENT APPLICATIONS) This application claims the benefit of U.S. Provisional Patent Application No. 63 / 377,538, filed September 29, 2022, entitled "SIDELINK BEAM ALIGNMENT WITH INTER-UE COORDINATION," the entirety of which is 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 alignment in sidelink communications. [Background technology]

[0003] Sidelink communication technology enables direct communication between two or more devices, for example, between two or more vehicles in vehicle-to-everything (V2X) communication.

[0004] 3rd Generation Partnership Project (3GPP) Release 16 / 17 5G NR sidelink modes 1 and 2 are specified in 3GPP TS 38.211, TS 38.212, TS 38.213, TS 38.214, TS 38.215, TS 38.321, TS 38.322, TS 38.323, and TS 38.331.

[0005] Release 17 introduces inter-user equipment (UE) coordination (IUC) to 5G NR sidelink mode 2, where UE-A sends coordination information about resources to UE-B, which then uses the information for resource (re)selection. Two methods of IUC are supported:

[0006] In IUC scheme 1, UE-A can provide another UE, UE-B, with an indication of resources that should be preferably included or excluded from UE-B's (re)selected resources. Given the resources to include, UE-B may rely solely on those resources, or combine them with resources identified by its own sensing procedure, before making a final selection, at least if it does not support sensing / resource exclusion. The indication from UE-A to UE-B is sent in a medium access control (MAC) control element (CE) and / or two stages of sidelink control information (SCI).

[0007] In IUC scheme 2, UE-A can provide an indication to another UE-B that resources reserved for UE-B's transmission (which may or may not be to UE-A) will or may conflict with a transmission from another UE-B. UE-B then reselects new resources to replace them. The indication from UE-A to UE-B may be sent in the physical sidelink feedback channel (PSFCH).

[0008] Sidelink communication in high frequency bands, e.g., mmWave bands, offers wide bandwidth and High-frequency bands enable high data rates. However, communications in high-frequency bands suffer from high path loss, which significantly limits communication range. To compensate for high path loss, beamforming using narrow beams or directional antennas is an effective method for providing sufficient communication range between two vehicles. However, beamforming between two vehicles in sidelink communications is typically challenging. This is because vehicles in sidelink communications may move and / or be located at similar altitudes, compared to beamforming in downlink / uplink communications between a base station and a UE, where the base station is typically stationary and located at a higher altitude than the UE. Due to these differences, procedures for beamforming in downlink / uplink communications between a base station and a UE may not be applicable to beamforming between two UEs in sidelink communications. Furthermore, beamforming in downlink / uplink communications between a base station and a UE, e.g., a procedure for performing an exhaustive search for the best beam pair, may be too slow, require a large amount of battery power, and may incur significant procedural and resource overhead. Improved systems and methods for beamforming in sidelink communications are desired. Summary of the Invention [Means for solving the problem]

[0009] According to some embodiments of the present disclosure, a method for sidelink communication is provided, the method including: receiving, by a first UE in sidelink communication, an IUC signal transmitted from a second UE; determining, by the first UE, a set of candidate radio resources for communication with the second UE based on the received IUC signal; determining, by the first UE, at least one direction associated with the received IUC signal based on an estimated angle of arrival of the received IUC signal; selecting, by the first UE, at least one beam for communication with the second UE from among a plurality of beams based on at least one of the determined at least one direction or content of the received IUC signal; determining, by the first UE, a subset of radio resources from the set of candidate radio resources based on sensing of the selected at least one beam; and transmitting, by the first UE, the determined subset of radio resources to the second UE or selecting, by the first UE, one or more radio resources for communication with the second UE from the determined subset of radio resources.

[0010] According to some embodiments of the present disclosure, a UE for communication is provided, the UE including: a memory storing instructions; and a processor configured to execute the instructions stored in the memory for receiving an IUC signal transmitted from a second UE; determining a set of candidate radio resources for communication with the second UE based on the received IUC signal; determining at least one direction associated with the received IUC signal based on an estimate of an angle of arrival of the received IUC signal; selecting at least one beam for communication with the second UE from among a plurality of beams based on at least one of the determined at least one direction or content of the received IUC signal; determining a subset of radio resources from the set of candidate radio resources based on sensing of the selected at least one beam; and transmitting the determined subset of radio resources to the second UE or selecting one or more radio resources for communication with the second UE from the determined subset of radio resources.

[0011] According to some embodiments of the present disclosure, a non-transitory computer-readable medium storing instructions executable by one or more processors of a first UE for communication performing a method is provided, the method including receiving, by the first UE, an IUC signal transmitted from a second UE, and determining, by the first UE, a second IUC signal based on the received IUC signal. determining, by the first UE, at least one direction associated with the received IUC signal based on an estimated angle of arrival of the received IUC signal; selecting, by the first UE, at least one beam from among the plurality of beams for communication with the second UE based on at least one of the determined at least one direction or content of the received IUC signal; determining, by the first UE, a subset of radio resources from the set of candidate radio resources based on sensing of the selected at least one beam; and transmitting, by the first UE, the determined subset of radio resources to the second UE or selecting, by the first UE, one or more radio resources for communication with the second UE from the determined subset of radio resources. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a schematic diagram illustrating an example inter-UE coordination scheme within a communication system, consistent with some embodiments of the present disclosure. [Figure 2] 2 is a schematic diagram illustrating an example beam alignment within the communication system of FIG. 1, consistent with some embodiments of the present disclosure. [Figure 3] FIG. 2 is a schematic diagram illustrating joint UE-to-UE coordination and sidelink beam alignment within the communication system of FIG. 1, consistent with some embodiments of the present disclosure. [Figure 4] FIG. 1 is a schematic diagram illustrating an example test setup for detecting directional transmissions, consistent with some embodiments of the present disclosure. [Figure 5] 1 is a flowchart illustrating a method for beam alignment in sidelink communications consistent with some embodiments of the present disclosure. [Figure 6] 1 is a flowchart illustrating a method for detecting directional transmissions consistent with some embodiments of the present disclosure. [Figure 7] FIG. 1 is a block diagram of a UE, consistent with some embodiments of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0013] Reference will now be made in detail to example embodiments, examples of which are illustrated in the accompanying drawings. The following description will refer to the accompanying drawings, in which like numbers in different drawings represent the same or similar elements, unless otherwise indicated. The implementations described in the following description of exemplary embodiments do not represent all implementations consistent with the present disclosure. Instead, the implementations are merely examples of systems, apparatus, and methods consistent with aspects related to the present disclosure as recited in the appended claims.

[0014] FIG. 1 is a schematic diagram illustrating an example inter-UE coordination scheme (referred to herein as a “first IUC scheme”) in a sidelink communication system consistent with some embodiments of the present disclosure. Referring to FIG. 1 , a communication system 100 includes a first UE (UE-A) and a second UE (UE-B) communicating with each other via sidelink communication. For example, the sidelink communication may be vehicle-to-everything (V2X) communication, in which UE-A and UE-B are both vehicles. UE-B may be a transmitter (Tx) UE configured or programmed to transmit signals or data to UE-A and / or other nodes (not shown) in the communication system 100. The other nodes may be network nodes (e.g., base stations), road side units (RSUs), relay nodes, or other UEs in the communication system 100. UE-A may be a receiver (Rx) UE configured or programmed to receive signals or data transmitted from UE-B and / or other nodes in the communication system 100.

[0015] In a first IUC scheme, UE-A may transmit coordination information (or Inter-UE Coordination (IUC) information) to UE-B before transmission of signaling and / or data from UE-B. The IUC information may include a set of preferred and / or non-preferred resources for UE-B's transmission. In some embodiments, the transmission of the IUC information from UE-A to UE-B may be triggered by UE-B. For example, UE-B may trigger the transmission of the coordination information by sending a request for IUC information to UE-A. The request for IUC information may be an explicit request or an implicit request.

[0016] In some embodiments, transmission of IUC information from UE-A to UE-B in the first IUC scheme is triggered by an explicit request. For example, UE-B may send a request to UE-A explicitly requesting IUC information from UE-A, or UE-A may receive the explicit request from UE-B and transmit the IUC information to UE-B. The transmission of the explicit request from UE-B and / or the reception of the explicit request by UE-A may be enabled, disabled, or controlled by configuration over the network or pre-configuration in UE-B and / or UE-A. In some embodiments, after receiving the IUC information, UE-B may transmit signals and / or data (e.g., transport blocks (TBs)) to UE-A. UE-B may transmit signals and / or data to one or more other nodes, such as one or more other UEs. The transmission of signals and / or data from UE-B may be enabled, disabled, or controlled by configuration or pre-configuration. UE-A and / or other nodes in the communication system may receive signals and / or data transmitted from UE-B. Reception of signals and / or data by UE-A may be enabled, disabled, or otherwise controlled by configuration or pre-configuration.

[0017] In some embodiments, transmission of IUC information from UE-A in the first IUC scheme may be triggered by an implicit request received from UE-B. An example of an implicit request may be a condition to be met by UE-A. If UE-A meets the condition, UE-A may transmit the IUC information to UE-B. UE-B may receive the IUC information from UE-A and use the IUC information for resource selection or reselection. The IUC information may include resources preferred by UE-B or resources not preferred by UE-B. The resources not preferred by UE-B may be resources already occupied or reserved by another UE. Resource selection or reselection by UE-B may be enabled, disabled, or controlled by configuration via the network or pre-configuration at UE-B.

[0018] 2 is a schematic diagram illustrating example beamforming within the communication system of FIG. 1 , consistent with some embodiments of the present disclosure. Referring to FIG. 2 , sidelink communication between UE-A and UE-B may be beam-based communication. In this case, sidelink beamforming is used to align the beam from UE-B (solid black oval 102) with the beam from UE-A (solid black oval 104). The terms “beam alignment” and “beamforming” are used interchangeably in this disclosure. Beamforming at the transmitter UE (e.g., UE-B) and / or receiver UE (e.g., UE-A) can increase communication range, achievable data rates on the sidelink, and overall system spectral efficiency by increasing spatial reuse of radio resources.

[0019] Referring to FIG. 2, UE-A and UE-B may both be located at low altitudes and may be moving. Also, in the sidelink, each UE communicates with one or more UEs. This differs from the uplink / downlink formed by the UE and the base station (e.g., gNB, eNB), where one end of the link (the base station) is usually stationary and located at a higher altitude than the other end of the link (the UE). Also, in the uplink / downlink communication, each UE communicates only with the base station. Due to these differences, the continuous beam alignment procedure used in the beamforming between the base station and the UE is required for the alignment of UE-A and UE-B. In some cases, the beamforming procedures used in the sidelink communication between the base station and the UE may not be applicable to the beamforming in the sidelink communication between the base station and the UE. Furthermore, even if the procedures used in the beamforming between the base station and the UE can be applied to the beamforming in the sidelink communication, the procedures for the beamforming between the base station and the UE, e.g., performing an exhaustive search for the best beam pair, may be too slow and may incur significant overhead. For example, the transmission and / or reception of reference signals using each possible beam pair during the search for the best beam may cause significant overhead. At least some embodiments of the present disclosure address the above-mentioned problems of the beamforming in the sidelink communication.

[0020] FIG. 3 is a schematic diagram illustrating joint IUC and sidelink beamforming in the communication system of FIG. 1 , consistent with some embodiments of the present disclosure. Referring to FIG. 3 , UE-A and UE-B are both ready to perform sidelink beam alignment and support and use a first IUC scheme. UE-A and UE-B may exchange signals for the first IUC scheme. For example, UE-B (Tx UE) may send an inter-UE coordination request (IUC_REQ) signal to UE-A (Rx UE). In an embodiment, UE-B may send an explicit request for IUC information. The IUC information may include a set of preferred and / or non-preferred radio resources for UE-B's resource selection and / or reselection. In an embodiment, the explicit request (or any implicit request) may be sent from UE-B and received by UE-A over the FR2 spectrum. In this disclosure, FR2 is defined by two frequency subranges: FR2-1 from 24,250 to 52,600 MHz, and FR2-2 from 52,600 to 71,000 MHz (including the mmWave spectrum). FR2 signals may be transmitted using one or more FR2 antennas. In another embodiment, an explicit request (or any implicit request) may be transmitted from UE-B and received by UE-A over the FR1 spectrum, for example, based on omnidirectional FR1 transmission and reception. In this disclosure, FR1 is defined as the frequency range from 410 to 7,125 MHz (including the sub-6 GHz spectrum). FR1 signals may be transmitted using one or more FR1 antennas. In some embodiments, generating a wide beam using an antenna panel used to generate a narrow beam (e.g., FR2) may be achieved by using a subset of antenna elements within the antenna panel. In some embodiments, a phase shift may be applied to each antenna element to produce a wider beam. In some embodiments, the range of the IUC may be increased by using a robust modulation coding scheme (MCS).

[0021] Upon receiving the IUC_REQ signal, UE-A determines the direction of arrival (DoA) (θ B , φ B ) may be determined. Methods for determining the direction of arrival are well established in the art. For the sake of brevity, the description of methods for determining the direction of arrival will be omitted here. B may be the angle between the x-axis and the incoming IUC_REQ signal, and angle φ B may be the angle between the y-axis and the incoming IUC_REQ signal. In some embodiments, UE-A may determine the elevation angle (the angle between the z-axis and the incoming IUC_REQ signal).

[0022] Based on the determined arrival direction of the incoming UE-to-UE coordination request (IUC_REQ) signal, UE-A may further select one or more Rx beams for subsequent communication with UE-B. For example, UE-A may select one or more narrow Rx beams from among a plurality of narrow Rx beams for subsequent reception of data from UE-B. In some embodiments, UE-A may determine two or more arrival directions of the incoming UE-to-UE coordination request (IUC_REQ) signal and select multiple Rx beam candidates based on the determination of the multiple arrival directions of the incoming UE-to-UE coordination request (IUC_REQ).

[0023] In some embodiments, UE-A may perform channel sensing on one or more selected Rx beams and determine IUC information for UE-B based on the sensing results for the selected one or more Rx beams. The IUC information may include preferred or non-preferred resources for UE-B.

[0024] In some embodiments, UE-A may further transmit an Inter-UE Coordination Message (IUC_MSG) to UE-B. The IUC_MSG may include IUC information determined by UE-A. In embodiments, UE-A may determine multiple Rx beam candidates, and the IUC_MSG transmitted to UE-B may include preferred and / or non-preferred radio resources for each Rx beam candidate. In some embodiments, the IUC_MSG may be transmitted from UE-A and received by UE-B using a wide FR2 beam. In some embodiments, the IUC_MSG may be transmitted from UE-A and received by UE-B using an omnidirectional FR1 antenna. In embodiments, based on the correlation between the Tx beam and the Rx beam, the transmission of the IUC_MSG by UE-A may use one or more Rx beams already selected by UE-A.

[0025] Upon receiving the IUC_MSG from UE-A, UE-B determines the direction of arrival (θ A , φ A ) may be determined. A may be the angle between the x-axis and the incoming IUC_MSG signal, and the angle φ A may be the angle between the y-axis and the incoming IUC_MSG signal. In some embodiments, UE-B may determine the elevation angle (the angle between the z-axis and the incoming IUC_MSG signal). UE-B may use the determined direction of arrival to select a Tx beam for subsequent communication with UE-A. For example, UE-B may select one or more narrow Tx beams from among multiple narrow Tx beams for subsequent transmission of data to UE-A. In some embodiments, UE-B may determine two or more directions of arrival of the IUC_MSG signal and select two or more candidate Tx beams based on the multiple directions of arrival of the IUC_MSG signal.

[0026] In some embodiments, UE-B may further perform channel sensing on the selected one or more Tx beams and select one or more resources based on the sensing results for the selected one or more Tx beams and the received IUC information. For example, UE-B may avoid selecting resources occupied or reserved by other UEs. In embodiments, UE-B may perform sensing on multiple Tx beam candidates and select a beam for transmission based on the sensing results obtained from the sensing on the multiple Tx beam candidates and the received IUC_MSG. UE-B may then transmit data to UE-A within the selected one or more resources using the selected beam.

[0027] In an embodiment, as part of resource selection for NR sidelink mode 2 as described in the 3GPP specifications, UE-A and UE-B may exchange IUC_REQ and IUC_MSG signals.

[0028] The method described above in connection with Figure 3 is a joint IUC in which both UE-A and UE-B perform direction of arrival estimation. In some embodiments, only one UE (UE-A or UE-B) may perform direction of arrival estimation.

[0029] Although example embodiments in this disclosure relate to FR1 and FR2 communications, application of the disclosed methods is not so limited. The methods described in this disclosure are applicable to frequency bands used in current sidelink communications as well as future generations (6th generation (6G), 7th generation (7G), or any other frequency bands). The methods described in this disclosure may be applied to any frequency band, including frequency bands used in sidelink communications of future generations (e.g., future generations). The methods described in this disclosure may also be applied to other systems, such as downlink / uplink or wireless local area networks, or any other system conforming to other standards (e.g., IEEE standards).

[0030] At least some embodiments of the disclosed method are beneficial for resource selection because sensing is performed on beams that will actually be used for subsequent data transmission and / or reception. Additionally, at least some embodiments of the disclosed method are beneficial for beam alignment because the method can enable fast beam alignment and reduced overhead without performing an exhaustive beam search based on beam sweeping. Furthermore, at least some embodiments of the disclosed method are applicable to both line-of-sight (LOS) and non-line-of-sight (NLOS) channels because the method can rely on direction-of-arrival estimation rather than geometry (e.g., UE position).

[0031] 4 is a schematic diagram illustrating an example test setup 400 for detecting directional transmissions, consistent with some embodiments of the present disclosure. Referring to FIG. 4, the test setup 400 includes two UEs, e.g., a smartphone (UB-B) and a vehicle (UE-A). UE-A is the UE under test. UE-A is positioned within a ring. An array of antennas is attached to the inner wall of the ring such that the Rx beam and / or Tx beam of UE-A are substantially perpendicular to the respective surfaces of each of the antennas. The two UEs may operate within FR2.

[0032] During the test, UE-B is triggered to send an Inter-UE Coordination Request (IUC-REQ) signal to UE-A. The IUC-REQ signal may be transmitted using a narrow beam or a wide beam (e.g., FR2) or an omnidirectional FR1 antenna. Referring to FIG. 4, for example, UE-B utilizes a narrow beam. The incoming IUC-REQ signal may be substantially perpendicular to the outer surface of the ring. UE-A receives the IUC-REQ and determines the direction of arrival of the incoming IUC-REQ signal.

[0033] Upon receiving the IUC-REQ signal, UE-A transmits an Inter-UE Coordination Message (IUC-MSG). For the IUC-MSG transmission, UE-A applies a beam that matches the direction of arrival of UE-B's IUC-REQ signal transmission. In this case, an antenna array mounted on the ring can detect the direction of transmission of the IUC-MSG signal from UE-A. Detection of the IUC-MSG signal by one or more antennas of the antenna array on the ring surface indicates that UE-A is performing the method disclosed in this disclosure.

[0034] 5 is a flowchart illustrating a method 500 for sidelink communication (e.g., for beam alignment and resource (re)selection), consistent with some embodiments of the present disclosure. Method 500 may be performed by a UE in sidelink communication. For example, method 500 may be performed by a vehicle in V2X communication.

[0035] Referring to FIG. 5, a method 500 includes receiving 502, by a first UE in sidelink communication, an inter-UE coordination (IUC) signal transmitted from a second UE.

[0036] In one embodiment, the first UE may be a transmitter UE in sidelink communication, such as UE-B in FIG. 3, and the IUC signal may be a UE-to-UE coordination message signal, such as the IUC_MSG signal in FIG. 3. The first UE may receive the IUC signal using at least one of FR2 or FR1. The IUC message signal may be transmitted to the first UE. The set of radio resources may include at least one of a set of radio resources that are preferred for transmitting signals or data from the first UE, or a set of radio resources that are not preferred for transmitting signals or data from the first UE. In this embodiment, before receiving the IUC message signal, the first UE transmits an IUC request signal to the second UE to request an IUC message, and receives the IUC message signal in response to the transmission of the IUC request signal. The IUC request may be an explicit request or an implicit request. In this case, one or more beams used to receive the IUC message signal from the second UE and one or more beams used to transmit the IUC request signal may have a mutual relationship.

[0037] In another embodiment, the first UE is a receiver UE in sidelink communication, such as UE-A in FIG. 3, and the IUC signal is an IUC request signal. The first UE may receive the IUC request signal using at least one of FR2 or FR1. In this embodiment, after receiving the IUC request signal, the first UE may transmit an IUC message signal to the second UE. The IUC message signal transmitted from the first UE may include at least one of a set of radio resources preferred for transmitting signals or data from the second UE or a set of radio resources not preferred for transmitting signals or data from the second UE. One or more beams used to transmit the IUC message signal from the first UE and one or more beams used to receive the IUC request signal may be interrelated.

[0038] The method 500 includes determining 504, by the first UE, a set of candidate radio resources for communication with the second UE based on the received IUC signaling.

[0039] In one embodiment, the first UE is a transmitter UE in sidelink communication, such as UE-B in FIG. 3, and the IUC signal is an IUC message signal. In this embodiment, based on the received IUC message signal, the first UE may determine a set of candidate radio resources for transmitting data or signals to the second UE. The first UE may determine the candidate resources based on the IUC message signal received from the second UE. In addition, the first UE may perform its own channel sensing and consider the channel sensing results. The transmission of the signal or data to the second UE may be broadcast, multicast, or unicast.

[0040] In another embodiment, the first UE is a receiver UE in sidelink communication, such as UE-A in FIG. 3, and the IUC signal is an IUC request signal. In this embodiment, upon receiving the IUC request signal, the first UE may determine a set of candidate radio resources for communication with the second UE. Alternatively, in this embodiment, step 504 is not performed.

[0041] The method 500 includes determining 506, by the first UE, at least one direction associated with the received IUC signal based on the estimated angle of arrival of the IUC signal.

[0042] In one embodiment, the first UE is a transmitter UE in sidelink communication, such as UE-B in FIG. 3, and the IUC signal is an IUC message signal. In this embodiment, the first UE may determine at least one direction associated with the received IUC message signal based on an estimated angle of arrival of the incoming IUC message. The estimated angle may be one or more angles between the IUC message signal direction and an x-axis, a y-axis, a z-axis, or any other reference axis.

[0043] In another embodiment, the first UE is a receiver UE in sidelink communication, such as UE-A in FIG. 3, and the IUC signal is an IUC request signal. In this embodiment, the first UE associates the received IUC request signal with the IUC request signal based on an estimated angle of arrival of the incoming IUC request signal. The estimated angle may be one or more angles between the IUC request signal direction and an x-axis, a y-axis, a z-axis, or any other reference axis.

[0044] The method 500 includes a step 508 of selecting, by the first UE, at least one beam from among the plurality of beams for communication with the second UE based on at least one of the determined at least one direction or the content of the received IUC signal.

[0045] In one embodiment, the first UE is a transmitter UE in sidelink communication, such as UE-B in Figure 3, and the IUC signal is an IUC message signal. In this embodiment, the first UE may select at least one beam for transmission (Tx beam) from among the multiple beams based on the determined direction associated with the received IUC message signal and / or the content of the IUC message signal (e.g., preferred resources of non-preferred resources for the first UE).

[0046] In another embodiment, the first UE is a receiver UE in sidelink communication, such as UE-A in FIG. 3, and the IUC signal is an IUC request signal. In this embodiment, the first UE may select at least one beam (Rx beam) from multiple beams for subsequent reception of data or signals from the second UE. In this embodiment, the first UE may select at least one beam (Rx beam) based on a determined direction associated with the received IUC request signal and / or the content of the IUC request signal.

[0047] The method 500 includes determining 510, by the first UE, a subset of radio resources from the set of candidate radio resources based on sensing for the at least one selected beam.

[0048] In one embodiment, the first UE is a transmitter UE in sidelink communication, such as UE-B in Figure 3, and the IUC signal is an IUC message signal. In this embodiment, the first UE may perform sensing on at least one selected beam (Tx beam) and determine a subset of radio resources from the candidate radio resources based on the sensing result.

[0049] In another embodiment, the first UE is a receiver UE in sidelink communication, such as UE-A in FIG. 3, and the IUC signal is an IUC request signal. In this embodiment, the first UE may perform sensing on the selected at least one Rx beam and determine a subset of radio resources from among the candidate radio resources based on the sensing result. In this embodiment, the first UE may perform sensing to determine inter-UE coordination information (e.g., preferred or non-preferred resources) of the second UE.

[0050] The method 500 includes a step 512 of transmitting, by the first UE, the determined subset of radio resources to the second UE or selecting, by the first UE, one or more radio resources from the determined subset of radio resources for communication with the second UE.

[0051] In an embodiment, the first UE is a transmitter UE in sidelink communication, such as UE-B in FIG. 3, and the IUC signal is an IUC message signal. In this embodiment, the first UE may transmit the determined subset of radio resources to the second UE. Alternatively, the first UE may select one or more radio resources for communication with the second UE from the determined subset of radio resources.

[0052] In another embodiment, the first UE is a receiver UE in sidelink communication, such as UE-A in FIG. 3, and the IUC signal is an IUC request signal. In this embodiment, the first UE may transmit the determined subset of radio resources to the second UE or select one or more radio resources from the determined subset of radio resources for communication with the second UE. Alternatively, in this embodiment, step 512 may not be performed.

[0053] 6 is a flowchart illustrating a method 600 for detecting directional transmissions consistent with some embodiments of the present disclosure. The method 600 may be performed by two UEs in sidelink communication. For example, the method 600 may be performed by a transmitter UE and a receiver UE in sidelink communication in the example test setup of FIG. 4.

[0054] Referring to Figure 6, method 600 includes step 602 of placing a first UE in a ring having multiple antennas arranged on an inner wall of the ring. The first UE is a UE being tested to determine whether it performs the method of Figure 5. The first UE may be capable of operating in an FR2 beam. The first UE may be a receiver UE in sidelink communication (e.g., UE-A in Figure 3). The first UE may be UE-A shown in Figure 4.

[0055] The method 600 includes step 604 of transmitting an Inter-UE Coordination (IUC) signal from the second UE to the first UE. The IUC signal may be an IUC request signal transmitted from the second UE. The IUC request signal may be transmitted using a narrow beam or a wide beam. The second UE may or may not implement the method of FIG. 5. The second UE may be capable of operating in an FR2 beam. The second UE may be UE-B shown in FIG. 6.

[0056] The method 600 includes receiving 606 a response signal transmitted from the first UE in response to the IUC signal. In an example in which the first UE implements the method of FIG. 5, upon receiving the IUC signal (e.g., an IUC request signal), the first UE determines the arrival direction of the IUC signal. The first UE further transmits a response signal (e.g., an IUC message signal) using a beam that coincides with the arrival direction of the IUC signal.

[0057] The method 600 includes determining 608 whether at least one direction associated with the response signal transmitted from the first UE matches a direction of the IUC signal. If the at least one direction associated with the response signal determined by one or more antennas on the inner wall of the ring matches a direction of the IUC signal, a conclusion may be made that the first UE is performing the method of FIG.

[0058] FIG. 7 is a block diagram of a UE 700 consistent with some embodiments of the present disclosure. The UE 700 may be a transmitter UE in sidelink communications, such as UE-B in FIG. 3, or a receiver UE in sidelink communications, such as UE-A in FIG. 3. The UE 700 may take any form, including, but not limited to, a vehicle, a vehicle-mounted component, a laptop computer, a wireless terminal including a mobile phone, a wireless handheld device, or a wireless personal device, or any other form. Referring to FIG. 7, the UE 700 may include an antenna 702 that may be used to transmit or receive electromagnetic signals to or from other nodes, such as a network node (e.g., a base station), an RSU, a relay node, or another UE. The antenna 702 may be an FR1 antenna configured to transmit and / or receive FR1 signals. Alternatively or additionally, the antenna 702 may be an FR2 antenna configured to transmit and / or receive FR2 signals. The antenna 702 may include one or more antenna elements and may be configured for various input / output antenna configurations, e.g., multiple-input multiple-output (MIMO) The antenna 702 may enable multiple input multiple output (MISO), multiple input single output (MISO), and single input multiple output (SIMO) configurations. In some embodiments, the antenna 702 may include multiple (e.g., tens or hundreds) antenna elements, enabling multi-antenna functionality such as beamforming. In some embodiments, the antenna 702 is a single antenna.

[0059] The UE 700 may include a transceiver 704 coupled to the antenna 702. The transceiver 704 may be a wireless transceiver in the UE 700 and may communicate bidirectionally with a base station or other UEs. For example, the transceiver 704 may receive / transmit wireless signals to / from a base station via downlink / uplink communication. The transceiver 704 may receive / transmit wireless signals to / from another UE or an RSU via sidelink communication. The transceiver 704 may include a modem for modulating packets and providing the modulated packets to the antenna 702 for transmission, and for demodulating packets received from the antenna 702.

[0060] The UE 700 may include memory 706. The memory 706 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 or special-purpose computer. Examples of non-transitory storage media include, but are not limited to, portable computer diskettes, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM), electrically erasable programmable ROM (EEPROM), digital versatile disks (DVDs), flash memory, compact disk (CD) ROM, or other optical disk storage, magnetic disk storage, or other magnetic storage devices. The non-transitory medium 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 or special-purpose computer or processor. In some examples, the software / program code may be transmitted over coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or other suitable communication medium. The information may be transmitted from a remote source (e.g., a website, a server, etc.) using wired or line, or wireless technologies such as infrared, radio, and microwave. In such examples, coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are within the definition of media. Combinations of the above examples are also within the scope of computer-readable media.

[0061] The memory 706 may store information related to the identity of the UE 700 and signals and / or data received by the antenna 702. The memory 706 may store post-processed signals and / or data. The memory 706 may store computer-readable program instructions, mathematical models, and algorithms used for signal processing in the transceiver 704 and calculations in the processor 708. For example, the memory 706 may store computer-readable program instructions, mathematical models, and algorithms used to estimate the angle of arrival of an IUC request signal and / or the angle of arrival of an IUC message signal. The memory 706 may be configured to perform various functions described in this disclosure. The memory 706 may further store computer-readable program instructions for execution by the processor 708 to operate the UE 700. In some examples, the memory 706 may include a basic input / output system (BIOS) that can control basic hardware or software operations, such as interacting with peripheral components or devices. In some embodiments, the memory 706 includes both an LTE module and an NR module. In some other embodiments, the memory 706 includes only an NR module. In some other embodiments, the memory 706 includes only an LTE module.

[0062] 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 code 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 be executed entirely on a computing device as a standalone software package, or may be executed partially on a first computing device and partially on a second computing device that is remote from the first computing device. In the latter situation, 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).

[0063] The UE 700 may include a processor 708, which may include hardware devices having processing capabilities. The processor 708 may be a general-purpose processor. It may include at least one of 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, discrete gate or transistor logic components, discrete hardware components, or other programmable logic devices. Examples of general-purpose processors include, but are not limited to, a microprocessor, any conventional processor, controller, microcontroller, or state machine. In some embodiments, the processor 708 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 any other such configuration). The processor 708 may receive downlink or sidelink signals from the transceiver 704 and further process those signals. The processor 708 may receive data packets from the transceiver 704 and further process those packets. In some embodiments, the processor 708 may be configured to operate the memory using a memory controller. In some embodiments, the memory controller may be integrated into the processor 708. The processor 708 may be configured to execute computer-readable instructions stored in a memory (e.g., memory 706) to cause the UE 700 to perform various functions.

[0064] The UE700 is a global positioning system (GPS) The GPS 710 may include a GPS system 710. The GPS 710 may be used to enable location-based services or other services based on the geographic location of the UE 700 and / or synchronization between UEs. The GPS 710 may receive signals from a single satellite or Global navigation satellite systems (GNSS) signals may be received from multiple satellite signals to provide the geographic location of the UE 700 (e.g., the coordinates of the UE 700). In some embodiments, the GPS 710 may be omitted.

[0065] The UE 700 may include input / output (I / O) devices 712 that can be used to communicate the results of signal processing and calculations to a user or another device. The I / O devices 712 may include a user interface, including a display and input devices for sending user commands to the processor 708. The display may be configured to display the status of signal reception at the UE 700, data stored in the memory 706, the status of signal processing, and calculation results. 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 devices 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.

[0066] The UE 700 may further include a machine interface 714 , such as an electrical bus, connecting the transceiver 704 , memory 706 , processor 708 , GPS 710 , and I / O devices 712 .

[0067] In some embodiments, the UE 700 may be configured or programmed for sidelink communications. For example, the UE 700 may be a transmitter UE or a receiver UE in sidelink communications, and the processor 708 may be configured to execute instructions stored in the memory 706, such as: receiving an IUC signal transmitted from a second UE; determining a set of candidate radio resources for communication with the second UE based on the received IUC signal; determining at least one direction associated with the received IUC signal based on an estimate of an angle of arrival of the received IUC signal; selecting at least one beam for communication with the second UE from among a plurality of beams based on at least one of the determined at least one direction or content of the received IUC signal; determining a subset of radio resources from the set of candidate radio resources based on sensing on the selected at least one beam; and transmitting the determined subset of radio resources to the second UE or selecting one or more radio resources for communication with the second UE from the determined subset of radio resources.

[0068] As used in this disclosure, the use of the word "or" in a list of terms indicates an inclusive list. A list of terms may be prefaced 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, prefaced with the phrase "based on" a list of conditions should not be interpreted as "based only on" the set of conditions, but rather 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.

[0069] As used herein, the terms "comprises," "includes," or "comprises" may be used interchangeably, have the same meaning, and should be construed as inclusive and open-ended. The terms "comprises," "includes," or "comprises" may be used after a list of elements to indicate that at least all of the listed elements in the list are present, but that other elements not in the list may also be present. For example, if A comprises B and C, then {B,C} and {B,C,D} are both within the scope of A.

[0070] The present disclosure, in connection with the accompanying drawings, describes exemplary configurations that are not representative of all examples that may be implemented, nor of 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." By reading this disclosure, including the description of the embodiments and drawings, those skilled in the art will understand that the technology disclosed herein may be implemented using alternative embodiments. Those skilled in the art will understand that the embodiments described herein, or specific features of the embodiments, can be combined to arrive at yet other embodiments for implementing the technology described in the present disclosure. Therefore, 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.

[0071] 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 occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, depending on the functionality involved, or the blocks may sometimes be executed in the reverse order. Likewise, additional steps may be included in such methods, or certain steps may be omitted or combined, in a manner consistent with various embodiments.

[0072] It is understood that the described embodiments are not mutually exclusive, and that elements, components, materials, or steps described in connection with one example embodiment may be combined with, or excluded from, other embodiments in any suitable manner to achieve desired design objectives.

[0073] References herein to "some embodiments" or "some exemplary embodiments" mean that a particular feature, structure, or characteristic described in connection with an embodiment may 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, and separate or alternative embodiments are not necessarily mutually exclusive of other embodiments.

[0074] Furthermore, the articles "a" and "an," as used in this disclosure and the appended claims, should generally be construed to mean "one or more," unless specifically indicated or clear from the context to mean singular.

[0075] Unless expressly stated otherwise, each numerical value and range should be construed as being approximate, as if the word "about" or "approximately" preceded the value or range.

[0076] The elements in the following method claims, if any, are recited in any particular order, but the elements of the claims Unless a listing specifically implies a particular order for performing some or all of the elements, the elements are not necessarily intended to be limited to being performed in that particular order.

[0077] It will be understood that certain features of the present disclosure that are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features herein that are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable subcombination, or as appropriate, in any other described embodiment herein. Particular features described in the context of various embodiments are not essential features of those embodiments, unless so noted.

[0078] It will be further understood that various changes, substitutions, and variations in the details, materials, and arrangements of parts explained and shown to explain the nature of the described embodiments may be made by those skilled in the art without departing from the scope thereof, and therefore the following claims will encompass all such alternatives, modifications, and variations that fall within the terms of the claims.

[0079] Item 1: A first user equipment (UE) for communication, wherein the first UE: a memory for storing instructions; and a processor configured to execute instructions stored in a memory, the instructions comprising: receiving an Inter-UE Coordination (IUC) signal transmitted from a second UE; determining a set of candidate radio resources for communication with the second UE based on the received IUC signal; determining at least one direction associated with the received IUC signal based on an estimate of an angle of arrival of the received IUC signal; selecting at least one beam from among the plurality of beams for communication with the second UE based on at least one of the determined at least one direction or content of the received IUC signal; determining a subset of radio resources from the set of candidate radio resources based on sensing for the selected at least one beam; and transmitting the determined subset of radio resources to the second UE or selecting, from the determined subset of radio resources, one or more radio resources for communication with the second UE.

[0080] Clause 2: The first UE of clause 1, wherein the arrival angle of the received IUC signal comprises at least one of an angle between an x-axis and the incoming IUC signal direction or an angle between a y-axis and the incoming IUC signal direction.

[0081] Clause 3: The first UE is a transmitter UE in sidelink communication, the IUC signal is an IUC message signal, and the processor is further configured to execute instructions stored in the memory, the instructions comprising: 10. The first UE of claim 1, for transmitting an IUC request signal to a second UE.

[0082] Clause 4: The first UE of clause 3, wherein the IUC request signal is transmitted using at least one of FR2 or FR1.

[0083] Clause 5: One or more beams used to receive an IUC message signal from the second UE, and one or more beams used to transmit an IUC request signal. 4. The first UE of claim 3, wherein the systems have a mutual relationship.

[0084] Clause 6: The first UE described in clause 1, wherein the first UE is a transmitter UE in sidelink communication, the IUC signal is an IUC message signal, and the IUC message signal includes at least one of (a) a set of radio resources that are preferred for transmitting signals or data from the first UE, or (b) a set of radio resources that are not preferred for transmitting signals or data from the first UE.

[0085] Clause 7: The first UE is a transmitter UE in sidelink communication, and the processor is further configured to execute instructions stored in the memory, the instructions comprising: 10. The first UE of claim 1, wherein the first UE transmits a signal or data to the second UE using the selected one or more radio resources.

[0086] Clause 8: The first UE is a receiver UE in sidelink communication, the IUC signal is an IUC request signal, and the processor is further configured to execute instructions stored in the memory, the instructions comprising: 10. The first UE of claim 1, for transmitting an IUC message signal to a second UE.

[0087] Clause 9: The first UE described in clause 8, wherein the IUC message signal includes at least one of (a) a set of radio resources that are preferred for transmitting signals or data from the second UE, or (b) a set of radio resources that are not preferred for transmitting signals or data from the second UE.

[0088] Clause 10: A first UE as described in clause 8, wherein one or more beams used to transmit an IUC message signal from the first UE and one or more beams used to receive an IUC request signal are interrelated.

[0089] Clause 11: The first UE of clause 8, wherein the IUC message signal is transmitted using at least one of FR2 or FR1.

[0090] Clause 12: The processor is further configured to execute instructions stored in the memory, the instructions comprising: 9. The first UE of claim 8, for receiving from the second UE a signal or data transmitted based on at least one of the at least one direction or the content of the IUC message signal.

[0091] Clause 13: The first UE of clause 1, wherein the set of candidate radio resources includes one or more subchannels or one or more slots for sidelink communication.

[0092] Item 14: A method for sidelink communication, comprising: receiving, by a first user equipment (UE) in sidelink communication, an inter-UE coordination (IUC) signal transmitted from a second UE; determining, by the first UE, a set of candidate radio resources for communication with the second UE based on the received IUC signal; determining, by the first UE, at least one direction associated with the received IUC signal based on the estimated angle of arrival of the received IUC signal; selecting, by the first UE, at least one beam from among the plurality of beams for communication with the second UE based on at least one of the determined at least one direction or content of the received IUC signal; determining, by the first UE, a subset of radio resources from the set of candidate radio resources based on sensing for the at least one selected beam; transmitting, by the first UE, the determined subset of radio resources to the second UE or selecting, by the first UE, one or more radio resources from the determined subset of radio resources for communication with the second UE.

[0093] Clause 15: The method of clause 14, wherein the angle of arrival of the received IUC signal comprises at least one of an angle between an x-axis and an incoming IUC signal direction or an angle between a y-axis and an incoming IUC signal direction.

[0094] Clause 16: The first UE is a transmitter UE in sidelink communication, and the IUC signal is an IUC message signal, and the method includes: 15. The method of clause 14, further comprising sending an IUC request signal to the second UE before receiving the IUC message signal.

[0095] Clause 17: The method of clause 16, wherein the IUC request signal is transmitted using at least one of FR2 or FR1.

[0096] Clause 18: The method of clause 16, wherein one or more beams used to receive an IUC message signal from the second UE and one or more beams used to transmit an IUC request signal have a correlation.

[0097] Clause 19: The method of clause 14, wherein the first UE is a transmitter UE in sidelink communication, the IUC signal is an IUC message signal, and the IUC message signal includes at least one of (a) a set of radio resources that are preferred for transmitting signals or data from the first UE, or (b) a set of radio resources that are not preferred for transmitting signals or data from the first UE.

[0098] Clause 20: The first UE is a transmitter UE in sidelink communication, and the method includes: 15. The method of clause 14, further comprising transmitting a signal or data to the second UE using the selected one or more radio resources.

[0099] Clause 21: The first UE is a receiver UE in sidelink communication, and the IUC signal is an IUC request signal, and the method includes: 15. The method of clause 14, further comprising transmitting an IUC message signal to the second UE.

[0100] Clause 22: The method of clause 21, wherein the IUC message signal is transmitted using at least one of FR2 or FR1.

[0101] Clause 23: The method of clause 21, wherein the IUC message signal includes at least one of (a) a set of radio resources that are preferred for transmitting signals or data from the second UE, or (b) a set of radio resources that are not preferred for transmitting signals or data from the second UE.

[0102] Clause 24: The method of clause 21, wherein one or more beams used to transmit an IUC message signal from the first UE and one or more beams used to receive an IUC request signal have a correlation.

[0103] Clause 25: From the second UE, at least one direction or content of the IUC message signal 22. The method of claim 21, further comprising receiving a signal or data transmitted based on at least one of:

[0104] Clause 26: The method of clause 14, wherein the set of candidate radio resources includes one or more subchannels or one or more slots for sidelink communication.

[0105] Clause 27: A non-transitory computer-readable medium storing instructions executable by one or more processors of a first user equipment (UE) for communication performing a method, the method comprising: receiving, by the first UE, an inter-UE coordination (IUC) signal transmitted from the second UE; determining, by the first UE, a set of candidate radio resources for communication with the second UE based on the received IUC signal; determining, by the first UE, at least one direction associated with the received IUC signal based on the estimated angle of arrival of the received IUC signal; selecting, by the first UE, at least one beam from among the plurality of beams for communication with the second UE based on at least one of the determined at least one direction or content of the received IUC signal; determining, by the first UE, a subset of radio resources from the set of candidate radio resources based on sensing for the at least one selected beam; transmitting, by the first UE, the determined subset of radio resources to the second UE, or selecting, by the first UE, one or more radio resources from the determined subset of radio resources for communication with the second UE.

Claims

1. A first user equipment (UE) for communication, the first UE comprising: a memory for storing instructions; and a processor configured to execute the instructions stored in the memory, the instructions comprising: receiving an Inter-UE Coordination (IUC) signal transmitted from a second UE; determining a set of candidate radio resources for communication with the second UE based on the received IUC signal; and determining at least one direction associated with the received IUC signal based on an estimate of an angle of arrival of the received IUC signal; selecting at least one beam from among a plurality of beams for communication with the second UE based on at least one of the determined at least one direction or content of the received IUC signal; determining a subset of radio resources from the set of candidate radio resources based on sensing for the selected at least one beam; transmitting the determined subset of radio resources to the second UE or selecting, from the determined subset of radio resources, one or more radio resources for communication with the second UE. A first user equipment (UE).

2. 2. The first user equipment (UE) of claim 1, wherein the angle of arrival of the received IUC signal comprises at least one of an angle between an x-axis and an incoming IUC signal direction or an angle between a y-axis and the incoming IUC signal direction.

3. the first UE is a transmitter UE in sidelink communication; the IUC signal is an IUC message signal; and the processor is further configured to execute the instructions stored in the memory, the instructions comprising: The first user equipment (UE) of claim 1, for transmitting an IUC request signal to the second UE.

4. The first user equipment (UE) of claim 3 , wherein the IUC request signal is transmitted using at least one of FR2 or FR1.

5. 4. The first user equipment (UE) of claim 3, wherein one or more beams used to receive the IUC message signal from the second UE and one or more beams used to transmit the IUC request signal have a correlation.

6. 2. The first user equipment (UE) of claim 1, wherein the first UE is a transmitter UE in sidelink communication, the IUC signal is an IUC message signal, and the IUC message signal includes at least one of (a) a set of radio resources that are preferred for transmission of signals or data from the first UE, or (b) a set of radio resources that are not preferred for transmission of signals or data from the first UE.

7. The first UE is a transmitter UE in sidelink communication, and the processor is further configured to execute the instructions stored in the memory, the instructions comprising:

10. The first user equipment (UE) of claim 1, for transmitting a signal or data to the second UE using the selected one or more radio resources.

8. The first UE is a receiver UE in sidelink communication, and the IUC signal is an IU C request signal, and the processor is further configured to execute the instructions stored in the memory, the instructions comprising: The first user equipment (UE) of claim 1 , for transmitting an IUC message signal to the second UE.

9. 10. The first user equipment (UE) of claim 8, wherein the IUC message signal includes at least one of: (a) a set of radio resources that are preferred for transmission of signals or data from the second UE; or (b) a set of radio resources that are not preferred for transmission of signals or data from the second UE.

10. 9. The first user equipment (UE) of claim 8, wherein one or more beams used to transmit the IUC message signal from the first UE and one or more beams used to receive the IUC request signal are interrelated.

11. The processor is further configured to execute the instructions stored in the memory, the instructions comprising:

9. The first user equipment (UE) of claim 8, for receiving from the second UE a signal or data transmitted based on at least one of the at least one direction or the content of the IUC message signal.

12. 2. The first user equipment (UE) of claim 1, wherein the set of candidate radio resources includes one or more subchannels or one or more slots for sidelink communication.

13. 1. A method for sidelink communication, comprising: receiving, by a first user equipment (UE) in the sidelink communication, an inter-UE coordination (IUC) signal transmitted from a second UE; determining, by the first UE, a set of candidate radio resources for communication with the second UE based on the received IUC signal; determining, by the first UE, at least one direction associated with the received IUC signal based on an estimated angle of arrival of the received IUC signal; selecting, by the first UE, at least one beam from among a plurality of beams for communication with the second UE based on at least one of the determined at least one direction or content of the received IUC signal; determining, by the first UE, a subset of radio resources from the set of candidate radio resources based on sensing of the selected at least one beam; transmitting, by the first UE, the determined subset of radio resources to the second UE, or selecting, by the first UE, one or more radio resources from the determined subset of radio resources for communication with the second UE.

14. 14. The method of claim 13, wherein the angle of arrival of the received IUC signal comprises at least one of an angle between an x-axis and an incoming IUC signal direction or an angle between a y-axis and the incoming IUC signal direction.

15. the first UE is a transmitter UE in the sidelink communication, the IUC signal is an IUC message signal, and the method comprises: The method of claim 13 , further comprising: sending an IUC request signal to the second UE before receiving the IUC message signal.

16. 14. The method of claim 13, wherein the first UE is a transmitter UE in the sidelink communication, the IUC signal is an IUC message signal, and the IUC message signal includes at least one of (a) a set of radio resources that are preferred for transmission of signals or data from the first UE, or (b) a set of radio resources that are not preferred for transmission of signals or data from the first UE.

17. the first UE is a transmitter UE in the sidelink communication, and the method further comprises: The method of claim 13 , further comprising transmitting a signal or data to the second UE using the selected one or more radio resources.

18. the first UE is a receiver UE in the sidelink communication, the IUC signal is an IUC request signal, and the method comprises: The method of claim 13 , further comprising transmitting an IUC message signal to the second UE.

19. 14. The method of claim 13, wherein the set of candidate radio resources comprises one or more subchannels or one or more slots for the sidelink communication.

20. 1. A non-transitory computer-readable medium storing instructions executable by one or more processors of a first user equipment (UE) for communication that performs a method, the method comprising: receiving, by the first UE, an inter-UE coordination (IUC) signal transmitted from the second UE; determining, by the first UE, a set of candidate radio resources for communication with the second UE based on the received IUC signal; determining, by the first UE, at least one direction associated with the received IUC signal based on an estimated angle of arrival of the received IUC signal; selecting, by the first UE, at least one beam from among a plurality of beams for communication with the second UE based on at least one of the determined at least one direction or content of the received IUC signal; determining, by the first UE, a subset of radio resources from the set of candidate radio resources based on sensing of the selected at least one beam; transmitting, by the first UE, the determined subset of radio resources to the second UE, or selecting, by the first UE, one or more radio resources from the determined subset of radio resources for communication with the second UE; 1. A non-transitory computer-readable medium comprising:

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