Method and apparatus for sidelink beam alignment

Abstract

A method, apparatus, and system for beam alignment in sidelink communications is disclosed, including a first UE configured to: receive a first wireless signal from a second UE using at least one first antenna; determine a first direction associated with the received first wireless signal based on an estimated angle of arrival of the received first wireless signal at the first UE; select a beam from among a plurality of beams for communication with the second UE based on the determined first direction; and transmit the second wireless signal to the second UE on the selected beam using at least one second antenna.

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED PATENT APPLICATIONS) This application claims the benefit of U.S. Provisional Patent Application No. 63 / 377,539, entitled "Sidelink beam alignment in V2X communication," filed September 29, 2022, 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, such as two or more vehicles in vehicle-to-everything (V2X) communications. For some sidelink communications, such as those requiring high data rates, transmitting and receiving data using high-frequency radio signals is preferred. However, high-frequency radio signals suffer from high path loss, which in turn limits the communication range between devices. Beamforming using narrow beams can provide compensation for path loss. Therefore, beamforming is useful for high-frequency operation in sidelink communications. However, beamforming between two vehicles in sidelink communications is typically challenging, especially when the two vehicles are moving. A system and method for efficient and accurate sidelink beamforming is desired. Summary of the Invention [Means for solving the problem]

[0004] According to some embodiments of the present disclosure, a first user equipment (UE) is provided, the first UE including: a memory storing instructions; and a processor configured to execute the instructions stored in the memory for receiving a first wireless signal from a second UE using at least one first antenna; determining a first direction associated with the received first wireless signal based on an estimated angle of arrival of the received first wireless signal at the first UE; selecting a beam for communication with the second UE from among a plurality of beams based on the determined first direction; and transmitting the second wireless signal to the second UE on the selected beam using at least one second antenna.

[0005] According to some embodiments of the present disclosure, a method for a first UE in sidelink communication is provided, the method including receiving a first wireless signal from a second UE using at least one first antenna, determining a first direction associated with the received first wireless signal based on an estimated angle of arrival of the received first wireless signal at the first UE, selecting a beam for communication with the second UE from among a plurality of beams based on the determined first direction, and transmitting the second wireless signal to the second UE on the selected beam using at least one second antenna.

[0006] 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 in sidelink communication to perform a method includes receiving a first wireless signal from a second UE using at least one first antenna, and determining a time domain associated with the received first wireless signal based on an estimated angle of arrival of the received first wireless signal at the first UE. determining a first direction; selecting a beam for communication with the second UE from among the plurality of beams based on the determined first direction; and transmitting a second wireless transmission to the second UE on the selected beam using at least one second antenna. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic diagram illustrating sidelink beamforming in a communication system consistent with some embodiments of the present disclosure. [Figure 2] FIG. 2 is a schematic diagram illustrating sidelink beamforming based on estimation of angle of arrival of sidelink signals in the communication system of FIG. 1 , consistent with some embodiments of the present disclosure. [Figure 3] FIG. 1 is a schematic diagram illustrating angle of arrival estimation using two FR1 omni-directional antennas located at a UE, consistent with some embodiments of the present disclosure. [Figure 4] FIG. 10 is a schematic diagram illustrating determining the angle of arrival of FR1 relative to the orientation of the FR2 antenna, consistent with some embodiments of the present disclosure. [Figure 5] FIG. 1 is a schematic diagram illustrating an example test setup including two UEs and a circular antenna array for detecting directional transmissions from one of the UEs, consistent with some embodiments of the present disclosure. [Figure 6] FIG. 10 is a schematic diagram illustrating another example test setup including two UEs and a circular antenna array for detecting directional transmissions from one of the UEs, consistent with some embodiments of the present disclosure. [Figure 7] 1 is a flowchart illustrating a method for beam alignment in sidelink communications consistent with some embodiments of the present disclosure. [Figure 8] 1 is a flowchart illustrating a method for detecting directional transmissions consistent with some embodiments of the present disclosure. [Figure 9] FIG. 1 is a block diagram of a UE, consistent with some embodiments of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0008] 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.

[0009] FIG. 1 is a schematic diagram illustrating sidelink beamforming in a communication system consistent with some embodiments of the present disclosure. Referring to FIG. 1, the 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. For example, 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), roadside units, 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.

[0010] Referring to Figure 1, sidelink communication between UE-A and UE-B may be beam-based communication. In this case, sidelink beamforming is used so that the beam from UE-B (solid black oval 102) and the beam from UE-A (solid black oval 104) are aligned. The terms "beam alignment" and "Beamforming" is used interchangeably in this disclosure. Aligning beams at UE-B and UE-A can increase communication range, achievable data rates on the sidelink, and overall system spectral efficiency.

[0011] Referring to FIG. 1, UE-A and UE-B may both be located at low altitudes and may both be moving. Furthermore, in the sidelink, each UE communicates with one or more UEs. These characteristics differ from the uplink / downlink formed by a UE and a base station (e.g., a gNB), where one end of the link (the base station) is typically stationary and located at a higher altitude than the other end of the link (the UE). Furthermore, in the uplink / downlink communications, each UE communicates only with the base station. Due to these differences, the continuous beam alignment procedure used in beamforming between a base station and a UE may not be applicable to sidelink beamforming between UE-A and UE-B. Furthermore, even if the procedure used in beamforming between a base station and a UE could be applied to sidelink beamforming, this procedure may be slow because it performs an exhaustive search for the best beam pair, which may incur significant overhead in sidelink beamforming. At least some embodiments of the present disclosure address the above-mentioned problems in sidelink beamforming.

[0012] FIG. 2 is a schematic diagram illustrating sidelink beamforming based on angle-of-arrival estimation of sidelink signals in the communication system of FIG. 1 , consistent with some embodiments of the present disclosure. Referring to FIG. 2 , UE-A and UE-B may periodically broadcast sidelink signals, such as cooperative awareness messages (CAMs) or basic safety messages (BSMs). The CAMs or BSMs may include information related to the transmitting UE (UE-A or UE-B), such as the current location, velocity, and orientation of the transmitting UE. Such broadcast messages may be transmitted using an omnidirectional antenna in an intelligent transportation systems (ITS) band (e.g., 5.9 GHz for the United States, EU, China, etc., or 760 MHz for Japan). These frequency bands correspond to frequency range 1 (FR1) in the 3rd Generation Partnership Project (3GPP) standard. The FR1 frequency range is from 410 to 7125 MHz. UE-A or UE-B may be equipped with one or more omnidirectional antennas for receiving FR1 signals (e.g., CAM) and may be capable of estimating one or more angle(s)-of-arrival (AoA) of the received FR1 signals. As used in this disclosure, the term "AoA" includes direction(s)-of-arrival (DoA), and in this disclosure, the terms AoA and DoA are used interchangeably. In some embodiments, as shown in FIG. 2, UE-B transmits CAM omnidirectionally, and UE-A estimates the angle(s)-of-arrival (φ) of the incoming CAM transmitted from UE-B. B Similarly, UE-A transmits CAM in all directions, and UE-B determines the arrival angle (φ A ) Methods for determining the angle of arrival are well known in the art. For the sake of brevity, the description of methods for determining the angle of arrival will be omitted herein.

[0013] In some embodiments, the contents of the received CAM (e.g., UE-A's location or UE-B's location) may be used to resolve any ambiguity (e.g., front / rear or left / right ambiguity) in estimating the angle of arrival. For example, the CAM broadcast from UE-A and received by UE-B may be used to determine the angle of arrival (φ) of the incoming CAM. A ) may include the location information of UE-A so that the location information can be used in determining the

[0014] In some embodiments, the estimated angle of arrival is used to select a higher frequency beam, e.g., an FR2 beam, for directional transmission or reception. The FR2 frequency range can have two frequency subranges: FR2-1 from 24250 to 52600 MHz and FR2-2 from 52600 to 71000 MHz. For example, UE-B may use the estimated angle of arrival (φ A ) may be used to select a beam for directional transmission of signals to UE-A using a directional antenna (e.g., a phased array).

[0015] At least some embodiments of the disclosed method enable fast and accurate sidelink beam alignment without performing an exhaustive search among all possible beam pairs, which is slower and incurs more overhead. Also, compared to approaches that rely solely on location information (e.g., zones or coordinates) for sidelink beam alignment, at least some embodiments of the disclosed method utilize estimated angles of arrival, thus leading to improved accuracy and enabling beam alignment even in non-line-of-sight (NLOS) situations.

[0016] In some embodiments, UE-A and / or UE-B may be equipped with multiple FR1 omni-directional antennas or multiple antenna panels such that angle of arrival estimation of FR1 signals may be performed using multiple FR1 omni-directional antennas or antenna panels, as described below in connection with FIG. 3.

[0017] 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 may be applied to any frequency band, including frequency bands used in current sidelink communications and frequency bands used in future generation sidelink communications (6th generation (6G), 7th generation (7G), or any future generation). 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).

[0018] FIG. 3 is a schematic diagram illustrating angle-of-arrival estimation using two FR1 omni-directional antennas disposed at a UE, consistent with some embodiments of the present disclosure. Referring to FIG. 3, a communication system 300 includes a first UE (UE-A), a second UE (UE-B), and a third UE (UE-C) communicating with each other via sidelink communication. For example, the sidelink communication may be V2X communication, and UE-A, UE-B, and UE-C are vehicles. FIG. 3 illustrates a top view of the vehicles. UE-A may receive FR1 signals (e.g., CAM) transmitted from UE-B and UE-C using two FR1 omni-directional antennas (A1, A2). Each of the two FR1 omni-directional antennas is disposed near a respective side of the vehicle. In some embodiments, the configuration of the two FR1 omni-directional antennas (A1, A2) may be in the form of a two-element linear array of antennas. Typically, the phase of the received FR1 signal at antenna A1 differs from the phase of the received FR1 signal at antenna A2 due to different path lengths and corresponding propagation delays (τ1, τ2). In some embodiments, UE-A may estimate the azimuth angle in the (x, y) plane corresponding to the direction in which the source of the transmitted FR1 signal (UE-B or UE-C) is located by comparing the phase of the received FR1 signal at each antenna.

[0019] There may be multiple angles at which the transmitted FR1 signal can arrive at different antennas with the same phase difference. For example, as shown in Figure 3, the signal (310) transmitted from UE-B may arrive at different antennas from the signal (310) transmitted from UE-C due to radial symmetry about the A1-A2 axis. The received FR1 signal may be received by UE-A's antenna A1 with the same phase difference as the transmitted signal (320). Therefore, UE-A may be unable to distinguish between the signal (320) coming from the left side of the A1-A2 axis and the signal (310) coming from the right side of the A1-A2 axis. This can cause left / right or vertical ambiguity. A similar ambiguity exists in the horizontal direction if A1 and A2 are positioned along UE-A's vertical axis. At least some embodiments of the present disclosure resolve such ambiguity by using location information included in the received FR1 signal. For example, the CAM received from UE-B may include information regarding the geographic coordinates (latitude, longitude, and altitude) of UE-B's current location. As another example, the sidelink control information (SCI) received from UE-B may include information regarding the zone identification (ID) corresponding to UE-B's current location. By combining the angle of arrival estimate with location information received from UE-B and / or UE-C, UE-A may achieve improved angle accuracy in estimating the angle of arrival.

[0020] In some embodiments, UE-A may receive FR1 (e.g., CAM) signals using three or more FR1 omni-directional antennas. The number of FR1 omni-directional antennas can be any number. For example, UE-A may receive FR1 signals transmitted from UE-B using four omni-directional antennas. The four omni-directional antennas may be located on the roof of UE-A, each at a corner of the roof of UE-A. The four antennas at the corners of the roof may form a 2×2 planar array of antennas. At least some embodiments of the present disclosure resolve the above-mentioned ambiguity (e.g., longitudinal ambiguity) by using three or more FR1 antennas without using location information of UE-B or UE-C.

[0021] In some embodiments, UE-A may perform FR2 beam selection based on the estimated angle of arrival of the FR1 signal. After UE-A obtains an estimate of the direction or angle (at least the azimuth angle) at which the FR1 signal transmitted by the signal source (UE-B or UE-C) arrives, UE-A may use this estimate to select a Tx or Rx beam pointing in a direction corresponding to directional communication with the signal source (e.g., UE-B or UE-C) over FR2 using a directional antenna (e.g., a phased array or antenna panel). In some embodiments, UE-A may select a Tx or Rx beam based on an implicit mapping between direction (or angle) and beam. Rules for such mapping may be predefined, preconfigured in UE-A, or configured by a network node. In some embodiments, prior to beam selection, UE-A may analyze the estimated angle of arrival (or direction of arrival) and determine its orientation relative to the coordinate system of the directional antenna (e.g., relative to the FR2 phased array). In some embodiments, this determination is obtained by preconfiguration during device manufacturing or by calibration.

[0022] FIG. 4 is a schematic diagram illustrating determining the angle of arrival of an FR1 with respect to the orientation of an FR2 antenna, consistent with some embodiments of the present disclosure. Referring to FIG. 4, a communication system 400 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 V2X communication, and UE-A and UE-B are vehicles. UE-A may receive an FR1 signal (e.g., CAM) transmitted from UE-B using four FR1 omnidirectional antennas (A1 through A4). The four FR1 omnidirectional antennas A1 through A4 are located on the roof of UE-A, each located at a corner of the roof. In some embodiments, the four antennas A1 through A4 at the corners of the roof are considered to be a 2×2 planar array of antennas.

[0023] Referring to Figure 4, UE-A transmits from UE-B using a 2x2 array on the roof. UE-B may estimate the angle of arrival (φ) of the received FR1 signal. The angle of arrival (φ) is given relative to the direction pointing toward the front of the vehicle (x-axis). As shown in FIG. 4 , UE-A also includes a directional FR2 antenna 410 located on the front bumper and a directional FR2 antenna 420 located on the side. When the FR2 antenna 410 is used for directional communication, the angle (φ) at which the beam should point relative to the normal vector (x̂) of the FR2 phased array is approximately the same as φ, especially when UE-B is located far away from UE-A. However, when the FR2 antenna 420 is used for directional communication, the angle (φ') at which the beam should point relative to the normal vector (ŷ) of the FR2 phased array is approximately (90-φ), especially when UE-B is located far away from UE-A. At least some embodiments of the present disclosure address the effect of different positions of the FR2 antenna by performing an analysis of the direction (or angle) determined by the angle of arrival estimation.

[0024] For example, in some embodiments, UE-A may perform an analysis of the angle of arrival observed at FR1 using a roof-top 2x2 array at FR1 to determine a direction relative to the coordinate system of directional antenna 410 or 420. For example, UE-A may analyze direction 440 observed at FR1 using a roof-top 2x2 array and account for clockwise or counterclockwise variations at FR2 antenna 410 or 420 to obtain direction 450 or 430 relative to FR2 antenna 410 or 420. In this way, the effects of different placements of FR1 and FR2 antennas as well as differences in distance between vehicles are removed, leading to improved beamforming accuracy.

[0025] The exemplary embodiment described with respect to FIG. 4 includes four FR1 antennas located on the roof of UE-A. However, the methods of the present disclosure are not so limited. The number of FR1 antennas can be any number, and the antennas can be located anywhere on the vehicle, for example, on the sides of the vehicle. Also, the FR2 antenna can be located anywhere on the vehicle, for example, on the rear bumper or on the roof of the vehicle.

[0026]

[0023] Figure 5 is a schematic diagram illustrating a first test setup for detecting directional transmissions from a device consistent with some embodiments of the present disclosure, and Figure 6 is a schematic diagram illustrating a second test setup for detecting directional transmissions from a device consistent with some embodiments of the present disclosure. Referring to Figures 5 and 6, each of the first test setup and the second test setup comprises a UE-A (e.g., a mobile phone), a UE-B (e.g., a vehicle), and a circular antenna array (e.g., multiple antennas arranged on the inner wall of a ring) for detecting directional transmissions from the vehicle. Compared to Figure 5, the second test setup in Figure 6 further includes a blocking surface 610 that blocks line-of-sight signals between UE-A and UE-B, and a highly reflective surface 620 that ensures that UE-B receives a strong non-line-of-sight component from UE-A's FR1 signal transmission.

[0027] In Figures 5 and 6, UE-A and UE-B are capable of operating in FR1 and FR2. UE-B is the UE under test, and UE-A is a controllable UE or software-defined radio platform. UE-B is placed within a ring with an array of antennas disposed on the inner wall of the ring. The array of antennas is mounted on the inner wall of the ring such that the Rx beam and / or Tx beam of UE-B are substantially perpendicular to the respective surfaces of each of the antennas.

[0028] 5, in the first test configuration, UE-A transmits an FR1 signal (e.g., CAM) and UE-B receives the FR1 signal. If UE-B transmits a narrow beam in FR2 toward UE-A without any FR2 beam alignment, this means that UE-B can obtain beam alignment information from the CAM received from UE-A.

[0029] Referring to FIG. 6, in a second test configuration, UE-A transmits an FR1 signal (e.g., CAM) and UE-B receives the FR1 signal. The CAM transmitted from UE-A is received by UE-B from a non-line-of-sight (NLoS) direction. The CAM transmitted from UE-A may include location information of UE-A. If UE-B performs narrow beam transmission in FR2 in the direction of arrival of the CAM transmitted from UE-A (NLoS component) instead of line-of-sight (LoS), this provides an indication that UE-B is implementing the method disclosed in the present disclosure.

[0030] 7 is a flowchart illustrating a method 700 for sidelink communication (e.g., for beam alignment) consistent with some embodiments of the present disclosure. Method 700 may be performed by a UE in sidelink communication. For example, method 700 may be performed by UE-A or UE-B of FIGS. 1-4.

[0031] Referring to FIG. 7, method 700 includes step 702 of receiving a first wireless signal from a second UE using at least one first antenna. For example, a first UE, such as UE-A in FIGS. 1-4, may receive a first wireless signal from a second UE, such as UE-B in FIGS. 1-4. In an embodiment, the first wireless signal may be an FR1 signal (e.g., CAM or BSM). In some embodiments, the at least one first antenna may be one or more FR1 omnidirectional antennas. For example, the at least one first antenna may be a two-antenna linear array as shown in FIG. 3 or a four-antenna linear array as shown in FIG. 4. The number of FR1 omnidirectional antennas may be any number, and the shape of the array formed by the FR1 omnidirectional antennas may be any shape (linear, rectangular, square, circular, etc.). In some embodiments, the at least one first antenna may be a single FR1 omnidirectional antenna including multiple antenna panels. In some embodiments, the first wireless signal may include location information providing the current location of the second UE. The location information may be the geographic coordinates (latitude, longitude, altitude) of the current location of the second UE, or a zone ID corresponding to the current location of the second UE.

[0032] The method 700 includes step 704 of determining a first direction associated with the received first wireless signal based on an estimated angle of arrival of the received first wireless signal at the first UE. For example, the first UE (e.g., UE-A in FIG. 4 ) determines a direction of the first incoming wireless signal (e.g., CAM) based on an estimate of the angle of arrival of the first wireless signal at the first UE. The estimated angle of arrival of the received first wireless signal at the first UE may include at least one of an angle between an x-axis and the first incoming wireless signal direction or an angle between a y-axis and the first incoming wireless signal direction. In some embodiments, the estimated angle of arrival of the received first wireless signal at the first UE may further include an angle between a z-axis and the first incoming wireless signal direction. In some embodiments, the first UE may select any other reference axis other than the x-axis, y-axis, or z-axis. In some embodiments, the at least one first antenna may include two or more omni-directional antennas, and the angle of arrival of the received first wireless signal may be estimated based on a comparison of the phase of the received first wireless signal at the two or more omni-directional antennas. In some embodiments, the received first wireless signal may include location information of the second UE, and in determining the angle of arrival of the first wireless signal, the first UE considers the location information of the second UE.

[0033] The method 700 includes selecting 706 a beam from among the plurality of beams for communication with the second UE based on the determined first direction. In some embodiments, the first UE selects a beam from among the plurality of beams based on a corresponding mapping between the plurality of beams and a plurality of directions of a plurality of signals incoming to the first UE. The corresponding mapping rule may be predefined, preconfigured in UE-A, or configured by a network node. In some embodiments, before selecting a beam from among the plurality of beams, the first UE may determine a direction of the beam from the at least one second antenna relative to a coordinate system of the at least one second antenna based on the determined first direction associated with the received first wireless signal. For example, the first UE may perform an analysis of the direction determined by the angle-of-arrival estimation of the first wireless signal to obtain the direction relative to the coordinate system of the second antenna, as described with respect to FIG. 4 above. The direction of the beam may be determined based on one or more parameters, such as a position of the second antenna at the first UE, a distance between the first UE and the second UE, etc.

[0034] The method 700 includes transmitting 708 a second radio signal on the selected beam to a second UE using at least one second antenna. The at least one second antenna may be at least one directional antenna that communicates with the second UE using an FR2 beam. In this manner, FR2 beam-based directional communication between the first UE and the second UE may be easily established using the aligned beams.

[0035] 8 is a flowchart illustrating a method 800 for detecting directional transmissions consistent with some embodiments of the present disclosure. Method 800 may be performed by two UEs in sidelink communication. For example, method 800 may be performed by UE-A and UE-B as shown in FIG. 5 or FIG. 6.

[0036] Referring to Figure 8, method 800 includes step 802 of placing a first UE in a ring having multiple antennas arranged along the periphery (inner wall) of the ring. The first UE is a UE being tested to determine whether it implements the method of Figure 7. The first UE may be capable of operating in an FR2 beam. The first UE may be a vehicle in V2X communication, such as the vehicles shown in Figures 5 and 6.

[0037] The method 800 includes transmitting 804 a first wireless signal from a second UE to the first UE. The first wireless signal may be an FR1 signal (e.g., CAM) transmitted from the second UE. The second UE may be capable of operating in an FR2 beam. The second UE may be a mobile phone, as shown in FIGS. 5 and 6.

[0038] The method 800 includes step 806 of receiving a response signal transmitted from the first UE in response to the first wireless signal. In an example in which the first UE implements the method of FIG. 7 , upon receiving the first wireless signal (e.g., CAM), the first UE determines an angle of arrival of the first wireless signal. The first UE may further analyze an estimated direction associated with the estimated angle of arrival to determine a direction relative to a coordinate system of the second antenna. The first UE may then select a beam and transmit the response signal on the selected beam using the second antenna.

[0039] The method 800 includes determining 808 whether a direction associated with a response signal transmitted from the first UE matches a direction of the first wireless signal. If the direction associated with the response signal determined by one or more antennas on the inner wall of the ring matches the direction of the first wireless signal, a conclusion may be made that the first UE is performing the method of FIG.

[0040] 9 is a block diagram of a UE 900 consistent with some embodiments of the present disclosure. The UE 900 may be a UE in sidelink communication, such as UE-A or UE-B of FIGS. 1-6. The UE 900 may be mounted in a moving vehicle or at a fixed location. The UE 900 may be a wireless terminal, including, but not limited to, a vehicle, a component mounted in a vehicle, a laptop computer, a mobile phone, a wireless handheld device, or a wireless personal device, or any other form. 9, the UE 900 may include an antenna 902 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), a road side unit (RSU), a relay node, a base station, or other UEs. The antenna 902 may be one or more FR1 omnidirectional antennas, such as antennas A1 and A2 of FIG. 3 or antennas A1-A4 of FIG. 4. The antenna 902 may also be one or more FR2 antennas, such as antenna 410 or antenna 420 of FIG. 4. The antenna 902 may include one or more antenna elements and may enable various input / output antenna configurations, such as 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, antenna 902 is a single antenna.

[0041] 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 receive / transmit wireless signals to / from another UE or an RSU 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.

[0042] The UE 900 may include 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 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. 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 or 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, 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 medium. Combinations of the above examples are also within the scope of computer-readable media.

[0043] The memory 906 may store information related to the identity of the UE 900 and signals and / or data received by the antenna 902. The memory 906 may store post-processed signals and / or data. The memory 906 may store computer-readable program instructions, mathematical models, and algorithms used for signal processing in the transceiver 904 and calculations in the processor 908. For example, the memory 906 may store computer-readable program instructions, mathematical models, and algorithms used to estimate the angle of arrival of an FR1 signal (e.g., CAM). 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 can control basic hardware or software operations, such as interacting with peripheral components or devices. In some embodiments, the memory 906 includes both an LTE module and an NR module. In some other embodiments, the memory 906 includes only an NR module. In some other embodiments, the memory 906 includes only an LTE module.

[0044] 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).

[0045] The UE 900 may include a processor 908, which may include hardware devices having 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, discrete gate or transistor logic components, discrete hardware components, or other programmable logic devices. 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 any other such configuration). The processor 908 may receive downlink or sidelink signals from the transceiver 904 and further process those signals. The processor 908 may receive data packets from the transceiver 904 and further process those packets. In some embodiments, the processor 908 may be configured to operate the memory using a memory controller. The UE 900 may be integrated into a processor 908. The processor 908 may be configured to execute computer-readable instructions stored in a memory (e.g., the memory 906) to cause the UE 900 to perform various functions.

[0046] The UE900 is a global positioning system (GPS) The UE 900 may include a 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 global navigation satellite systems (GNSS) signals from a single satellite or multiple satellite signals via the antenna 902 and provide the geographic location of the UE 900 (e.g., coordinates of the UE 900). In some embodiments, the GPS 910 may be omitted.

[0047] 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 input devices for sending user commands to the processor 908. The display may be configured to display the status of signal reception at the UE 900, data stored in the memory 906, 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.

[0048] The UE 900 may further include a machine interface 914 , such as an electrical bus, connecting the transceiver 904 , memory 906 , processor 908 , GPS 910 , and I / O devices 912 .

[0049] In some embodiments, the UE 900 may be configured or programmed for sidelink communication. For example, the UE 900 may be a first UE in sidelink communication, and the processor 908 may be configured to execute instructions stored in the memory 906 for receiving a first wireless signal from a second UE using at least one first antenna, determining a first direction associated with the received first wireless signal based on an estimated angle of arrival of the received first wireless signal at the first UE, selecting a beam for communication with the second UE from among a plurality of beams based on the determined first direction, and transmitting the second wireless signal to the second UE on the selected beam using at least one second antenna.

[0050] 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, a list of conditions may be prefaced with the phrase "based on." A result described as "based at least in part on" a set of conditions should not be construed as "based only on" a 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 the present disclosure.

[0051] As used herein, the terms "comprise," "include," or "comprise" are used interchangeably, may have the same meaning, and should be construed as inclusive and open-ended. The terms "comprise," "include," or "comprise" 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.

[0052] 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.

[0053] 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, and certain steps may be omitted or combined, in a manner consistent with various embodiments.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] Unless expressly stated otherwise, each numerical value and range is referred to as "about" or "approximately." The value or range of values ​​should be interpreted as an approximation, as if the word "approximate" preceded the value or range of values.

[0058] Although elements in the following method claims, if any, are recited in a particular order, unless the recitation of a claim specifically implies a particular order for performing some or all of those elements, those elements are not necessarily intended to be limited to being performed in that particular order.

[0059] 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.

[0060] 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.

[0061] 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 a first wireless signal from a second UE using the at least one first antenna; determining a first direction associated with the received first wireless signal based on an estimated angle of arrival of the received first wireless signal at the first UE; selecting a beam from among the plurality of beams for communication with the second UE based on the determined first direction; and transmitting a second radio signal on the selected beam to a second UE using at least one second antenna.

[0062] Clause 2: The first UE of clause 1, wherein the at least one first antenna is a plurality of omnidirectional antennas and the at least one second antenna is at least one directional antenna.

[0063] Clause 3: The first UE of clause 1, wherein the communication is directional communication between the first UE and the second UE.

[0064] Clause 4: The processor is further configured to execute instructions stored in the memory, the instructions comprising: The first UE of claim 1, which is configured to determine a direction of a beam from at least one second antenna relative to a coordinate system of the at least one second antenna based on at least a first direction associated with a received first radio signal before selecting a beam from among the plurality of beams.

[0065] Clause 5: The first UE of clause 1, wherein the received first wireless signal includes location information providing a location of the second UE.

[0066] Clause 6: In determining a first direction associated with the received first wireless transmission, the processor is further configured to execute instructions stored in the memory, the instructions comprising: 6. The first UE of claim 5, wherein the first UE is for determining a first direction based on at least one radio measurement of a received first radio signal and location information.

[0067] Clause 7: The first UE of clause 5, wherein the location information includes at least one of geographic coordinates of the second UE or a zone ID corresponding to a current location of the second UE.

[0068] Clause 8: The first UE of clause 1, wherein the first wireless signal is a Cooperative Awareness Message (CAM) or a Basic Safety Message (BSM).

[0069] Clause 9: The first UE of clause 1, wherein the first radio signal is transmitted using FR1.

[0070] Clause 10: The first UE of clause 1, wherein at least one second antenna is configured to communicate with the second UE using FR2.

[0071] Clause 11: The first UE described in clause 1, wherein the at least one first antenna includes a plurality of first antennas, and the angle of arrival of the received first radio signal is estimated based on a comparison of the phase of the received first radio signal at two or more antennas of the plurality of first antennas.

[0072] Clause 12: The first UE described in clause 1, wherein an arrival angle of the received first wireless signal at the first UE includes at least one of an angle between an x-axis and the first incoming wireless signal direction or an angle between a y-axis and the first incoming wireless signal direction.

[0073] Clause 13: The first UE of clause 12, wherein the angle of arrival further includes an elevation angle at the first UE.

[0074] Clause 14: The first UE described in clause 1, wherein a beam is selected from among a plurality of beams based on a correspondence mapping between the plurality of beams and a plurality of directions of a plurality of signals coming into the first UE.

[0075] Clause 15: The first UE of clause 1, wherein the first UE is a vehicle and the at least one second antenna is a linear array of antennas arranged along a longitudinal or lateral axis of the vehicle.

[0076] Clause 16: The first UE of clause 1, wherein the first UE is a vehicle and the at least one first antenna is located on a roof of the vehicle.

[0077] Clause 17: A method for a first user equipment (UE) in sidelink communication, comprising: receiving a first wireless signal from a second UE using the at least one first antenna; determining a first direction associated with the received first wireless signal based on an estimated angle of arrival of the received first wireless signal at the first UE; selecting a beam from among the plurality of beams for communication with the second UE based on the determined first direction; and transmitting a second radio signal on the selected beam using at least one second antenna. and transmitting to the second UE.

[0078] Clause 18: The method of clause 17, wherein the at least one first antenna is a plurality of omnidirectional antennas and the at least one second antenna is at least one directional antenna.

[0079] Clause 19: The method of clause 17, wherein the communication is directional communication between the first UE and the second UE.

[0080] Clause 20: The method of clause 17, further comprising, before selecting a beam from among the plurality of beams, determining a direction of the beam from the at least one second antenna relative to a coordinate system of the at least one second antenna based at least on a determined first direction associated with the received first radio signal.

[0081] Clause 21: The method of clause 17, wherein the received first wireless signal includes location information providing a location of the second UE.

[0082] Clause 22: The method of clause 21, wherein determining a first direction associated with the received first wireless signal further includes determining the first direction based on at least one radio measurement of the received first wireless signal and location information.

[0083] Clause 23: The method of clause 21, wherein the location information includes at least one of geographic coordinates of the second UE or a zone ID corresponding to a current location of the second UE.

[0084] Clause 24: The method of clause 17, wherein the first wireless signal is a Cooperative Awareness Message (CAM) or a Basic Safety Message (BSM).

[0085] Clause 25: The method of clause 17, wherein the first radio signal is transmitted using FR1.

[0086] Clause 26: The method of clause 17, wherein at least one second antenna is configured to communicate with the second UE using FR2.

[0087] Clause 27: The method of clause 17, wherein the at least one first antenna includes a plurality of first antennas, and the angle of arrival of the received first radio signal is estimated based on a comparison of phases of the received first radio signal at two or more antennas of the plurality of first antennas.

[0088] Clause 28: The method of clause 17, wherein the angle of arrival of the received first wireless signal at the first UE comprises at least one of an angle between an x-axis and the first incoming wireless signal direction or an angle between a y-axis and the first incoming wireless signal direction.

[0089] Clause 29: The method of clause 28, wherein the angle of arrival of the received first wireless signal at the first UE further includes an elevation angle at the first UE.

[0090] Clause 30: The method of clause 17, wherein a beam is selected from among the plurality of beams based on a correspondence mapping between the plurality of beams and a plurality of directions of a plurality of signals coming into the first UE.

[0091] Clause 31: The method of clause 17, wherein the first UE is a vehicle and the at least one second antenna is a linear array of antennas arranged along a longitudinal or lateral axis of the vehicle.

[0092] Clause 32: The method of clause 17, wherein the first UE is a vehicle and the at least one first antenna is disposed on a roof of the vehicle.

[0093] Item 33: 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 a first wireless signal from a second UE using the at least one first antenna; determining a first direction associated with the received first wireless signal based on an estimated angle of arrival of the received first wireless signal at the first UE; selecting a beam from among the plurality of beams for communication with the second UE based on the determined first direction; and transmitting a second wireless transmission on the selected beam to a second UE using at least one second antenna.

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 a first wireless signal from a second UE using at least one first antenna; determining a first direction associated with the received first wireless signal based on an estimated angle of arrival of the received first wireless signal at the first UE; selecting a beam from among a plurality of beams for communication with the second UE based on the determined first direction; and transmitting a second radio signal on the selected beam to the second UE using at least one second antenna.

2. 2. The first user equipment (UE) of claim 1, wherein the at least one first antenna is a plurality of omnidirectional antennas and the at least one second antenna is at least one directional antenna.

3. 2. The first user equipment (UE) of claim 1, wherein the communication is a directional communication between the first UE and the second UE.

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

2. The first user equipment (UE) of claim 1, wherein before selecting the beam from the plurality of beams, the first user equipment (UE) is configured to determine a direction of the beam from the at least one second antenna relative to a coordinate system of the at least one second antenna based on at least the first direction associated with the received first radio signal.

5. The first user equipment (UE) of claim 1 , wherein the received first wireless signal includes location information providing a location of the second UE.

6. The first user equipment (UE) of claim 1 , wherein the first wireless signal is a Cooperative Awareness Message (CAM) or a Basic Safety Message (BSM).

7. The first user equipment (UE) of claim 1 , wherein the first radio signal is transmitted using FR1.

8. 2. The first user equipment (UE) of claim 1, wherein the at least one second antenna is configured to communicate with the second UE using FR2.

9. 2. The first user equipment (UE) of claim 1, wherein the at least one first antenna comprises a plurality of first antennas, and the angle of arrival of the received first wireless signal is estimated based on a comparison of a phase of the received first wireless signal at two or more antennas of the plurality of first antennas.

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

11. 2. The first user equipment (UE) of claim 1, wherein the beam is selected from among the plurality of beams based on a correspondence mapping between the plurality of beams and a plurality of directions of a plurality of signals coming into the first UE.

12. 2. The first user equipment (UE) of claim 1, wherein the first UE is a vehicle and the at least one second antenna is a linear array of antennas positioned along a longitudinal or lateral axis of the vehicle.

13. 1. A method for a first user equipment (UE) in sidelink communication, comprising: receiving a first wireless signal from a second UE using at least one first antenna; determining a first direction associated with the received first wireless signal based on an estimated angle of arrival of the received first wireless signal at the first UE; selecting a beam from among a plurality of beams for communication with the second UE based on the determined first direction; and transmitting, using at least one second antenna, a second wireless signal on the selected beam to the second UE.

14. The method of claim 13 , wherein the at least one first antenna is a plurality of omnidirectional antennas and the at least one second antenna is at least one directional antenna.

15. The method of claim 13 , wherein the communication is a directional communication between the first UE and the second UE.

16. 14. The method of claim 13, further comprising, prior to selecting the beam from among the plurality of beams, determining a direction of the beam from the at least one second antenna relative to a coordinate system of the at least one second antenna based at least on the determined first direction associated with the received first radio signal.

17. The method of claim 13 , wherein the received first wireless signal includes location information providing a location of the second UE.

18. 14. The method of claim 13, wherein the at least one first antenna comprises a plurality of first antennas, and the angle of arrival of the received first wireless signal is estimated based on a comparison of a phase of the received first wireless signal at two or more antennas of the plurality of first antennas.

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

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 a first wireless signal from a second UE using at least one first antenna; determining a first direction associated with the received first wireless signal based on an estimated angle of arrival of the received first wireless signal at the first UE; selecting a beam from among a plurality of beams for communication with the second UE based on the determined first direction; transmitting a second radio transmission on the selected beam to the second UE using at least one second antenna; 1. A non-transitory computer-readable medium comprising:

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