Beam maintenance in sidelink communications

Abstract

A first user equipment (UE) for maintaining a sidelink beam in sidelink communications, the first UE comprising: a memory storing instructions; and a processor configured to execute the instructions stored in the memory for: obtaining resource reservation information and future location information for the first UE, where the future location information for the first UE includes an estimated first location of the first UE at a first time after a current time; transmitting the resource reservation information and future location information for the first UE to a second UE; receiving a signal from the second UE including the future location information of the second UE, where the future location information for the second UE includes an estimated second location of the second UE at the first time; and determining one or more beams for transmission from the first UE based on the future location information of the second UE.

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED PATENT APPLICATIONS) This application claims the benefit of U.S. Provisional Patent Application No. 63 / 377,436, filed September 28, 2022, entitled "EXCHANGE OF FUTURE UE POSITION FOR SIDELINK BEAM TRACKING IN MILLIMETER-WAVE BANDS," 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 sidelink beam maintenance 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. A first vehicle in a sidelink communication can provide resource reservation information to one or more other vehicles, for example, using periodic broadcasts of sidelink signals, to prevent other vehicles from selecting the same resource for transmission. This scheme may work well for sidelink communications using low-frequency bands (e.g., 5.9 GHz or lower). However, resource reservation and resource selection for sidelink communications using high-frequency bands (e.g., millimeter wave bands) are more complex. For high-frequency radio signals that suffer from high propagation loss, beamforming using narrow beams is commonly used to compensate for the propagation loss. However, beam alignment is difficult and changes over time, especially when vehicles are moving. Improved systems and methods for beam maintenance in beam-based sidelink communications are desired. Summary of the Invention [Means for solving the problem]

[0004] According to some embodiments of the present disclosure, a first user equipment (UE) for maintaining a sidelink beam in sidelink communications is provided, the first UE including: a memory storing instructions; and a processor configured to execute the instructions stored in the memory for: obtaining resource reservation information and future location information for the first UE, where the future location information for the first UE includes an estimated first location of the first UE at a first time after a current time; transmitting the resource reservation information and future location information for the first UE to a second UE; receiving a signal from the second UE including the future location information of the second UE, where the future location information for the second UE includes an estimated second location of the second UE at the first time; and determining one or more beams for transmission from the first UE based on the future location information of the second UE.

[0005] According to some embodiments of the present disclosure, a second UE for maintaining a sidelink beam in sidelink communications is provided, the second UE including: a memory storing instructions; and a processor configured to execute the instructions stored in the memory, the instructions including: receiving, from the first UE, resource reservation information and future location information of the first UE, the future location information of the first UE including an estimated first location of the first UE at a first time after a current time; and transmitting a signal to the first UE in response to receiving the resource reservation information and future location information of the first UE, the signal including an estimated first location of the second UE at a first time after a current time. The second UE includes future location information of the first UE, the future location information of the second UE includes an estimated second position of the second UE at a first time, and determining one or more beams for reception by the second UE based on the future location information of the first UE.

[0006] According to some embodiments of the present disclosure, a method for maintaining a sidelink beam in sidelink communications is provided, the method including: acquiring, by a first UE, resource reservation information and future location information for the first UE, where the future location information for the first UE includes an estimated first location of the first UE at a first time after a current time; transmitting the resource reservation information and future location information for the first UE to a second UE; receiving, from the second UE, a signal including the future location information of the second UE, where the future location information for the second UE includes an estimated second location of the second UE at the first time; and determining one or more beams for transmission from the first UE based on the future location information of the second UE.

[0007] According to some embodiments of the present disclosure, a method for maintaining a sidelink beam in sidelink communications is provided, the method including: receiving, by a second UE, resource reservation information and future location information for the first UE from a first UE, the future location information for the first UE including an estimated first location of the first UE at a first time after a current time; transmitting a signal to the first UE in response to receiving the resource reservation information and the future location information for the first UE, the signal including the future location information of the second UE, the future location information for the second UE including an estimated second location of the second UE at the first time; and determining one or more beams for reception by the second UE based on the future location information of the first UE.

[0008] 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 to perform a method is provided, the method including: obtaining resource reservation information and future location information for the first UE, where the future location information for the first UE includes an estimated first location of the first UE at a first time after a current time; transmitting the resource reservation information and future location information for the first UE to a second UE; receiving a signal from the second UE including the future location information of the second UE, where the future location information for the second UE includes an estimated second location of the second UE at the first time; and determining one or more beams for transmission from the first UE based on the future location information of the second UE.

[0009] According to some embodiments of the present disclosure, a non-transitory computer-readable medium storing instructions executable by one or more processors of a second UE to perform a method is provided, the method including: receiving, from a first UE, resource reservation information and future location information for the first UE, the future location information for the first UE including an estimated first location of the first UE at a first time after a current time; transmitting a signal to the first UE in response to receiving the resource reservation information and the future location information for the first UE, the signal including future location information of a second UE, the future location information for the second UE including an estimated second location of the second UE at the first time; and determining one or more beams for reception by the second UE based on the future location information of the first UE. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a flowchart illustrating a method for resource selection in sidelink communications, consistent with some embodiments of the present disclosure. [Figure 2A] 2 is a schematic diagram illustrating a resource candidate determination procedure according to the method of FIG. 1, consistent with some embodiments of the present disclosure. [Figure 2B]2 is a table illustrating a correspondence between sub-carrier spacing (SCS) and subsets of resources according to the method of FIG. 1, consistent with some embodiments of the present disclosure. [Figure 3] 3A and 3B are schematic diagrams illustrating transmission of resource reservation information in sidelink communications, consistent with some embodiments of the present disclosure, and resource collision avoidance using the resource reservation information in sidelink communications of FIG. 3A, consistent with some embodiments of the present disclosure. [Figure 4] FIG. 1 is a schematic diagram illustrating sidelink beamforming in a communication system consistent with some embodiments of the present disclosure. [Figure 5] 5A and 5B are schematic diagrams illustrating side information exchange and side information-aided beam maintenance in low-frequency sidelink communication, consistent with some embodiments of the present disclosure. [Figure 6] FIG. 10 is a schematic diagram illustrating the exchange of estimated future positions for beam maintenance in beam-based sidelink communication, consistent with some embodiments of the present disclosure. [Figure 7] FIG. 1 is a schematic diagram illustrating a method for indicating an estimated future location of a UE, consistent with some embodiments of the present disclosure. [Figure 8] FIG. 1 is a schematic diagram illustrating an example communication procedure for sidelink communication, consistent with some embodiments of the present disclosure. [Figure 9] 1 is a flowchart illustrating a method for sidelink beam maintenance in sidelink communications, consistent with some embodiments of the present disclosure. [Figure 10] 1 is a flowchart illustrating a method for sidelink beam maintenance in sidelink communications, consistent with some embodiments of the present disclosure. [Figure 11] FIG. 1 is a block diagram of a UE, consistent with some embodiments of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0011] 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.

[0012] FIG. 1 is a flowchart illustrating a method 100 for resource selection in sidelink communications consistent with some embodiments of the present disclosure. FIG. 2A is a schematic diagram illustrating a resource candidate determination procedure according to the method of FIG. 1, consistent with some embodiments of the present disclosure. FIG. 2B is a table illustrating a correspondence between SCSs and resource subsets according to the method of FIG. 1, consistent with some embodiments of the present disclosure. Method 100 may be performed by a UE in sidelink communications. For example, method 100 may be performed by a vehicle in V2X communications. Method 100 may be performed according to a mode employing orthogonal frequency division multiplexing (OFDM) at the physical (PHY) layer for sidelink communications. An example of this mode is 3GPP (3rd Generation Partnership Project) Release 16 / 17 5G NR-V2X PC5 Mode 2.

[0013] Referring to Figure 2A, the time-frequency radio resource is divided into slots in the time domain and subchannels in the frequency domain. In an embodiment, this mode is 15*2 m kHz SCS can be supported, where m is the OFDM numerology m∈{0, 1, 2, 3, 4}. For frequencies below 6 GHz, 15, 30, and 60 kHz (i.e. , m∈{0,1,2}) may be supported, while for frequencies above 6 GHz, SCSs of 60, 120, and 240 kHz (i.e., m∈{2,3,4}) may be supported. The length of each slot is ½ m ms and consists of 14 OFDM symbols. Each subchannel can consist of multiple consecutive physical resource blocks (PRBs), each PRB being 180*2 m occupies 15*2 kHz m Each subchannel consists of 12 subcarriers with an SCS of 1 kHz. The size of the subchannel (i.e., the number of PRBs per subchannel) is configurable or preconfigurable. To support multiple SCSs and different Doppler spreads, multiple demodulation reference signal (DMRS) density options (2 to 4 DMRS symbols per slot) may be used. Each UE may transmit first-stage sidelink control information (SCI) and data (e.g., transport blocks (TBs)) in the physical sidelink control channel (PSCCH) and second-stage SCI in the physical sidelink shared channel (PSSCH). Hybrid automatic repeat request (HARQ) feedback (e.g., acknowledgement / negative acknowledgement (ACK) or NACK only) may be transmitted in the physical sidelink feedback channel (PSFCH).

[0014] FIG. 2B illustrates a schematic diagram of an SCS and a sensing and selection window (T SL proc,0 and TSL proc,1 ) parameters. For example, when the SCS is 15 kHz, as shown in the second and third columns of Figure 2B, T SL proc,0 corresponds to 1 ms, and T SL proc,1 corresponds to 3 ms. As another example, if the SCS is 30 kHz, T SL proc,0 corresponds to 0.5 ms, and T SL proc,1 corresponds to 2.5ms.

[0015] 1, the method 100 includes step 102 of performing channel sensing (e.g., background sensing or any other type of full or partial sensing). For example, as shown in FIG. 2A, the UE may perform a sensing window T sensing (For example, T sensing =[T0,T SL proc,0 ], in Figure 2B, T0 = 100 or 1100 ms, and T SL proc,0 A UE may perform channel sensing within a 100 ms sensing window to collect resource reservation information for one or more other UEs. Channel sensing using a 100 ms sensing window may be for aperiodic traffic, while channel sensing using a 1100 ms sensing window may be for periodic traffic.

[0016] The method 100 includes step 104 of collecting resource reservation information of one or more other UEs and measuring corresponding sidelink-reference signal received power (SL-RSRP). For example, as shown in FIG. 2A, the UE may perform channel sensing within a sensing window and collect resource reservation information of one or more other UEs based on decoding of the SCI to identify candidate resources. In an embodiment, to perform channel sensing to obtain information for receiving packets from other UEs, the UE first performs decoding of the SCI. The decoding of the SCI may include two stages: a first-stage SCI (SCI format 1-A) and a second-stage SCI (SCI format 2-A or 2-B), as defined in the 3GPP specifications. The first The first-stage SCI may carry information regarding resource reservation information for future transmissions, resource allocation, PSSCH modulation and coding scheme (MCS), DMRS pattern, and second-stage SCI format, etc. The second-stage SCI may carry control information for HARQ procedures, source / destination identifications (IDs), information regarding distance-based groupcast (e.g., UE zone ID and communication range requirements), etc. Based on the resource reservation information included in the first-stage SCI, the UE can avoid using time and / or frequency resources reserved by other UEs when performing resource selection or resource reselection.

[0017] The method 100 includes determining 106 candidate resources by excluding occupied, reserved, and / or unmonitored resources. For example, the UE may exclude unmonitored slots from the selection window T (e.g., T=[T1, T2], where 0= <T1=<T SL proc,1 ms, and T in Figure 2B. SL proc,1が(T2 may be set based on the remaining packet delay budget). The UE may be unable to sense unmonitored slots in the sensing window, for example, due to its own transmission (e.g., half-duplex constraints). The UE may further exclude resources occupied or reserved by other UEs from the selection window if the corresponding SL-RSRP exceeds a configured or preconfigured SL-RSRP exclusion threshold. After the resource exclusion, the number of candidate resources may be at least X% of the total number of resources in the selection window. If this is not the case, the UE may increase the SL-RSRP exclusion threshold, for example, by 3 dB, until at least X% of the resources are obtained, where X may be configured or preconfigured from {20, 35, 50}%.

[0018] The method 100 includes a step 108 of selecting a resource from among the candidate resources. The selection may be a random selection. For example, as shown in FIG. 2A, the UE may select a resource from among the candidate resources within a selection window. The selected frequency resource may be selected using semi-persistent scheduling (SPS). It can be used multiple times at fixed time intervals in the case of one-shot scheduling, or just once in the case of one-shot transmission (OST).

[0019] In some embodiments, method 100 may utilize a UE-to-UE coordination scheme in which one or more other UEs transmit coordination information regarding resources to the UE, and the UE utilizes the information for resource selection or resource reselection. The UE-to-UE coordination scheme may include a first UE-to-UE coordination scheme and a second UE-to-UE coordination scheme. According to the first UE-to-UE coordination scheme, the UE may receive, from one or more other UEs, an indication of resources that are preferably included or excluded from the UE's selected or reselected resources. In embodiments, when the resource indication indicates inclusion of certain resources, if the indication does not support sensing and / or resource exclusion, the UE may rely solely on those resources. In embodiments, the UE may combine the resource indication with resources identified by its own sensing procedure before making a final selection. The UE may receive the indication via a medium access control (MAC) control element (CE) and / or a second-stage SCI. According to a second inter-UE coordination scheme, a UE may receive an indication that resources reserved for the UE's transmission conflict or may conflict with a transmission from another UE. In this case, the UE may reselect new resources. The UE may receive the indication via a PSFCH. The UE may define a mapping rule between a PSSCH allocation (e.g., one or more slots and subchannels) and the PSFCH resources. A mapping table may be used that defines the PSFCH resource allocation. Using the mapping table, the UE (and the transmitter UE) can determine the PSSCH allocation to which the information in the PSFCH resource refers. If more than one subchannel is reserved in the PSSCH, multiple PSFCH resources may be used. The mapping table may be predefined, preconfigured in the UE, or configured by a network node.

[0020] The method 100 includes a step 110 of checking resource availability based on reevaluation and / or preemption of the selected resource. This step may be performed for later arriving packets (e.g., aperiodic packets) after resource selection and before packet transmission.

[0021] Method 100 includes step 112 of determining whether resource reselection is required. If it is determined that resource reselection is required, the method may repeat from step 104. On the other hand, if it is determined that resource reselection is not required, the method may proceed with step 114 of transmitting a packet based on the SPS or OST. The packet may be an initial packet or a retransmitted packet. The UE may retransmit the packet multiple times (e.g., HARQ retransmissions) with or without feedback from the receiver UE to improve the reliability of the transmission. After step 114, method 100 may repeat from step 102.

[0022] 3A and 3B are schematic diagrams illustrating transmission of resource reservation information in sidelink communication consistent with some embodiments of the present disclosure, and resource collision avoidance using the resource reservation information in the sidelink communication of FIG. 3A , consistent with some embodiments of the present disclosure. Referring to FIGS. 3A and 3B , a sidelink communication system includes a UE 302, a UE 304, a UE 306, a UE 308, and a UE 310. For simplicity, FIG. 3A shows only the UE 302 and the UE 304. The UE 302 is a transmitter (Tx) UE (e.g., an omni-directional Tx UE) in the sidelink communication, and the UE 304 is a receiver (Rx) UE (e.g., an omni-directional Rx UE) in the sidelink communication. The UE 302 may reserve resources for data transmission, encode the resource reservation information in an SCI, and transmit the SCI using, for example, one or more omni-directional antennas. As shown in FIG. 3, the SCI may include time and / or frequency resources for retransmissions scheduled by the UE 302, SPS time intervals, and other information. Other UEs in the sidelink communication system (e.g., UE 306, UE 308, and UE 310 in FIG. 3B) may receive the SCI and decode it to obtain the resource reservation information of the UE 302. The other UEs obtain the time and / or frequency resources reserved by the UE 302 and thus can avoid using the same resources when performing resource selection or resource reselection. In this way, resource collisions may be avoided.

[0023] The above-described resource reservation and resource selection schemes may be useful for sidelink communications based on low frequency bands, e.g., FR1 beams. In this disclosure, FR1 is defined as the frequency range from 410 to 7125 MHz (including the sub-6 GHz spectrum). However, the above schemes may not be applicable to sidelink communications based on high frequency bands (e.g., FR2). In this disclosure, FR2 is defined as two frequency subranges: FR2-1 from 24250 to 52600 MHz and FR2-2 from 52600 to 71000 MHz (including the millimeter-wave spectrum). For high-frequency radio signals that are adversely affected by high propagation loss, beamforming using narrow beams is commonly used to provide sufficient beamforming gain to compensate for the propagation loss. However, beam alignment is challenging and changes over time, especially when the UE is moving. Therefore, beam tracking (or maintenance) is required for sidelink communications based on high frequency bands (e.g., beam-based). The terms "beam tracking," "beam maintenance," and "beam management" are used interchangeably in this disclosure. At least some embodiments of the present disclosure provide a method for beam maintenance for beam-based sidelink communications.

[0024] FIG. 4 is a schematic diagram illustrating beam maintenance for beam-based sidelink communications consistent with some embodiments of the present disclosure. Referring to FIG. 4, a communication system 400 includes a first UE (UE 402) and a second UE (UE 404) communicating with each other via sidelink communications using high-frequency band signals (e.g., FR2). For example, the sidelink communications may be vehicle-to-everything (V2X) communications, where both the UE 402 and the UE 404 are vehicles. Within the communication system 400, the UE 402 may be a Tx UE, and the UE 404 may be an Rx UE. Because the sidelink communications between the UE 402 and the UE 404 use high-frequency signals, sidelink beamforming is used so that the beams from the UE 402 and the UE 404 can be aligned. As shown in FIG. 4, the beam 410 from the UE 402 and the beam 412 from the UE 404 are a pair of previously aligned beams. However, due to the dynamic nature of beam alignment in the system, beam 410 and beam 412 from UE 402 are no longer aligned. Upon realignment, beam 406 from UE 402 and beam 408 from UE 404 are now aligned. The terms "align," "realign," and "beamforming" (and similar terms, e.g., aligned, alignment, realigned, and realignment) are used interchangeably in this disclosure.

[0025] FIG. 5A is a schematic diagram illustrating side information exchange in low-frequency sidelink communication consistent with some embodiments of the present disclosure, and FIG. 5B is a schematic diagram illustrating side information-assisted beam maintenance in sidelink communication consistent with some embodiments of the present disclosure. Referring to FIGS. 5A and 5B, a communication system includes a UE 502 and a UE 504 communicating with each other via sidelink communication. For example, the sidelink communication may be V2X communication, in which the UE 502 and the UE 504 are both vehicles. In the communication system, the UE 502 may be a Tx UE, and the UE 504 may be an Rx UE. In some embodiments, as shown in FIG. 5A, the UE 502 and the UE 504 exchange side information using low-frequency band signals (e.g., below 6 GHz) using, for example, an omnidirectional antenna. The exchanged side information may include, for example, the current location, velocity, and predicted route of the UE 502 or the UE 504. The UE 502 and the UE 504 may exchange side information periodically (e.g., every 100 ms). For example, UE 502 and UE 504 may exchange side information by periodically broadcasting sidelink signals such as European Telecommunications Standards Institute (ETSI) cooperative awareness messages (CAMs) or Society of Automotive Engineers (SAE) basic safety messages (BSMs).

[0026] Because UE 502 and UE 504 can detect their relative positions with each other by periodically exchanging BSMs or CAMs at low frequencies, they can also detect changes in their relative angles and adjust their beams accordingly. As shown in FIG. 5B, beam 510 from UE 502 and beam 512 from UE 504 are a pair of previously aligned beams, while beam 506 from UE 502 and beam 508 from UE 504 are realigned after beam maintenance. In some embodiments, after side information exchange, UE 502 and UE 504 may be configured to communicate with each other for beam-based sidelink communications. The E504 may perform beam alignment using a limited number (small number) of candidate training pairs, for example, the three beam pairs identified by the dashed ellipse in FIG. 5B. The selected three beam pairs may cover a specific angle space instead of the entire angle space depending on the position or angle estimation error. In some embodiments, using BSM or CAM, the UE 502 and the UE 504 may further share predicted path information. The predicted (or estimated) path may be a path that the transmitting UE is expected to traverse in the form of a radius of curvature. By exchanging predicted path information, the UE 502 and the UE 504 can estimate when beams need to be realigned and train a limited number of beam candidates based on the predicted path information, so that beam tracking overhead can be further reduced. The UE 502 and the UE 504 may exchange side information via at least one of the PHY layer, the MAC layer, or a higher layer (such as the network layer, the transport layer, or the application layer).

[0027] FIG. 6 is a schematic diagram illustrating the exchange of estimated future locations for beam maintenance in beam-based sidelink communication, consistent with some embodiments of the present disclosure. Referring to FIG. 6, a sidelink communication system 600 includes a Tx UE and an Rx UE communicating with each other via beam-based sidelink communication. The sidelink communication may be V2X communication, in which the Tx UE and the Rx UE are both vehicles. The Tx UE and the Rx UE may exchange future location information (e.g., zone IDs and subzone IDs) at lower layers (e.g., PHY and MAC layers) for beam tracking and resource reservation. First, the Tx UE and the Rx UE may exchange their estimated future locations. The future location may be an estimated (e.g., predicted) location at a time later than the current time. For example, as shown in FIG. 6, at time T0, the Tx UE transmits a sidelink signal to the Rx UE indicating that the Tx UE's estimated future location at time T1 (a time later than T0) is zone ID A. Upon receiving the sidelink signal from the Tx UE, at T0′, the Rx UE may send a response signal (e.g., a confirmation) to the Tx UE indicating that the Rx UE's estimated future location at T1 is zone ID B. Then, during a period including T1 (e.g., either before, during, or after T1), the Tx UE and the Rx UE may determine and possibly adjust their Tx and Rx beams, respectively, based on the exchanged future location information. The Tx UE and the Rx UE may then communicate using the determined (and possibly adjusted) Tx and Rx beams. In this manner, beam tracking (maintenance) with low signaling overhead for beam-based sidelink communication in the mmWave band may be achieved.

[0028] The procedure shown in FIG. 6 is merely one example embodiment. The scope of the present disclosure is not so limited. In an embodiment, the Tx beam determination and possible adjustment at the Tx UE and the Rx beam determination and possible adjustment at the Rx UE may occur at different times. For example, the Tx UE may perform the Tx beam determination and possible adjustment at a first event, and the Rx UE may perform the Rx beam determination and possible adjustment at a second event, where the first event and the second event occur at two different times but within a specific time range. The time range may be configured by the network node or at the Tx UE and the Rx UE.

[0029] In an embodiment, T0 and T0' may be the same time. For example, the Rx UE may transmit a sidelink signal to the Tx UE indicating that the Rx UE's estimated future location at T1 is zone ID B, and at the same time, the Tx UE transmits a sidelink signal to the Rx UE indicating that the Tx UE's estimated future location at T1 is zone ID A. In this embodiment, the sidelink signal transmitted from the Rx UE indicates that the Tx UE's estimated future location at T1 is zone ID A. It may be an unsolicited signal rather than a response (or confirmation) to a sidelink signal received from the UE. In another embodiment, T0' may be earlier than T0 (i.e., the Rx UE may transmit its sidelink signal before the Tx UE transmits its sidelink signal).

[0030] FIG. 7 is a schematic diagram illustrating a method for indicating an estimated future location of a UE, consistent with some embodiments of the present disclosure. In some embodiments, as shown in FIG. 7, multiple two-dimensional (2D) zones are configured. Each zone has a unique identification (ID) number (e.g., 1, 2, 3, 4, ..., 132). For example, a zone with an ID of 1 is configured. Each dimension (e.g., width and length) L of the zone is also configured, for example, 1, 5, 10, 20, 30, 40, 50 m (e.g., when each zone is two-dimensional and substantially square). The dimension L of the zone can be any other value, for example, smaller than 1 m or larger than 50 m. In this manner, the estimated future location of the UE is indicated using the ID of the zone in which the UE is expected to be located. In some embodiments, instead of 2D zones, 3D zones corresponding to 3D beamforming (i.e., horizontal beamforming and vertical beamforming) are also configured.

[0031] In some embodiments, finer sub-zones corresponding to zones within a conventional zone are used for beam management, thereby improving the resolution of position indication. For example, the conventional zone ID may be used to determine the upper left edge position of the zone, while the finer (new) zone ID may be used to identify the sub-zone for beamforming purposes.

[0032] In an embodiment, for example, the subzones may be determined as follows: x1=Floor(x) Mod L y1=Floor(y) Mod L Sub-Zone_id=y1*L+x1 where L is the dimension of said zone contained in the sidelink zone configuration (sl-ZoneConfig), x is the geodesic distance in longitude between the current location of the UE and the geographic coordinate (0,0) according to the WGS84 model, expressed in meters, and y is the geodesic distance in latitude between the current location of the UE and the geographic coordinate (0,0) according to the WGS84 model, expressed in meters.

[0033] FIG. 8 is a schematic diagram illustrating an example communication procedure for sidelink communication consistent with some embodiments of the present disclosure. Referring to FIG. 8, this procedure includes the following steps: Initially, at time T0, the Tx UE may transmit one or more packets to the Rx UE. The one or more packets may include one or more TBs and an SCI. The SCI includes an estimated future location (e.g., a zone ID and a subzone ID) of the Tx UE at T1 (a time after T0). The estimated future location may be conveyed as at least one of an SCI at the PHY layer, a MAC CE at the MAC layer, or higher layer information (e.g., using a radio resource control (RRC) protocol). The SCI may include a resource reservation for a HARQ packet and / or a next TB packet transmitted on T1. In some embodiments, the Tx UE may transmit the one or more packets and the SCI separately. In some embodiments, the Tx UE may transmit only the SCI.

[0034] Next, at time T0' (T0' is later than T0 but earlier than T1), Rx After the UE receives one or more packets and / or SCI from the Tx UE, the Rx UE sends a signal (e.g., an ACK). The signal indicates the Rx UE's The estimated future location of the Rx UE may include the Rx UE's estimated future location (e.g., zone ID and subzone ID). The estimated future location of the Rx UE may be carried by at least one of an SCI at the PHY, a MAC CE at the MAC layer, or higher layer information (e.g., using the RRC protocol).

[0035] In an embodiment, T0 and T0' are the same time. For example, the Rx UE may transmit a sidelink signal to the Tx UE indicating that the Rx UE's estimated future location at T1 is zone ID B, and at the same time, the Tx UE transmits a sidelink signal to the Rx UE indicating that the Tx UE's estimated future location at T1 is zone ID A. In this embodiment, the sidelink signal transmitted from the Rx UE indicates that the Rx UE's estimated future location at T1 is zone ID A. It is an unsolicited signal, rather than a response (or confirmation) to a sidelink signal received from the Tx UE indicating that the UE's estimated future location is in zone ID B. In another embodiment, T0' may be earlier than T0 (i.e., the Rx UE may transmit its sidelink signal before the Tx UE transmits its sidelink signal).

[0036] After T0', the Tx UE may perform beam training and / or refinement on one or more beams among the plurality of candidate Tx beams. Similarly, the Rx UE may perform beam training and / or refinement on one or more beams among the plurality of candidate Rx beams. In some embodiments, the Tx UE and the Rx UE may The UEs perform beam training and / or refinement simultaneously. In some embodiments, the Tx UE and the Rx UE perform beam training and / or refinement at different times. In some embodiments, both the Tx UE and the Rx UE omit beam training and / or refinement. In some embodiments, only one of the Tx UE and the Rx UE performs beam training and / or refinement.

[0037] During a period including T1 (e.g., either before, during, or after T1), the Tx UE determines (and possibly adjusts) one or more Tx beams for transmission from the Tx UE based on the Rx UE's future location information at T1. Also, during a period including T1, the Rx UE determines (and possibly adjusts) one or more Rx beams for reception by the Rx UE based on the Tx UE's future location information at T1. In an embodiment, the Tx UE and the Rx UE perform the determination (and possible adjustment) of their respective one or more Tx beams and one or more Rx beams simultaneously. In another embodiment, the Tx UE and the Rx UE may perform the determination (and possible adjustment) of their respective one or more Tx beams and one or more Rx beams at different times. For example, a Tx UE may perform a Tx beam decision (and possible adjustment) in a first event, and an Rx UE may perform an Rx beam decision (and possible adjustment) in a second event, where the first and second events are at different times but within a certain duration, which may be configured by a network node or at the Tx UE and / or the Rx UE.

[0038] The Tx UE may then transmit one or more packets to the Rx UE. The one or more packets may include an SCI containing estimated future location information of the Tx UE at T2 (T2 is a time later than T1). The SCI may include resource reservation information. The above procedure may then be repeated. In some embodiments, the Tx UE may omit transmission after beam determination (and possible adjustment), and the process is repeated from the beginning (at T0). In some embodiments, the Tx UE may transmit one or more packets and the SCI separately. In some embodiments, the Tx UE may transmit only the SCI.

[0039] In some embodiments, the predicted future position of the UE is calculated assuming constant velocity and heading. 7)。 In some embodiments, the expected future position of the UE may be calculated using a simple estimation technique based on the UE's current position, velocity, and heading. In some embodiments, the expected future position of the UE may be calculated using a more advanced estimation technique that takes into account vehicle dynamics. The future position information may be indicated by SCI in the FR1 band (e.g., 5.9 GHz) and / or FR2 mmWave band. In some embodiments, the dimension L of the zone (as shown in FIG. 7) is small enough (e.g., 1 m or less) so that the position information is useful for beam management.

[0040] The methods described in this disclosure may be applied to any sidelink communication, for example, long term evolution (LTE) or new radio (NR) or future generation (6th generation (6G), 7th generation (7G), or any future generation) sidelink communication. The methods described in this disclosure may also be applied to downlink / uplink communication between a base station and a UE. The methods described in this disclosure may also be applied to other systems, for example, other standards (e.g., Institute of Electrical and Electronics Engineers (IEEE)). It may also be applied to systems that comply with the IEC 61002-1 (International Standards Association) (IEC 61002-1).

[0041] 9 is a flowchart illustrating a method 900 for sidelink beam maintenance in sidelink communications, consistent with some embodiments of the present disclosure. Method 900 may be performed by a Tx UE in sidelink communications, such as the Tx UEs of FIGS. 6 and 8.

[0042] The method 900 includes obtaining 902, by a first UE, resource reservation information and future location information for the first UE, where the future location information of the first UE includes an estimated first location of the first UE at a first time after the current time. In some embodiments, the first UE determines the estimated first location of the first UE at the first time based on at least one of a current location of the first UE, a velocity of the first UE, an orientation of the first UE, or a planned trajectory of the first UE.

[0043] The method 900 includes transmitting 904 resource reservation information and future location information of the first UE to the second UE. In some embodiments, the first UE may transmit the resource reservation information and future location information of the first UE using a low frequency band (e.g., FR1). In some embodiments, the first UE may transmit the resource reservation information and future location information of the first UE using a high frequency band (e.g., FR2 or a mmWave frequency band).

[0044] In some embodiments, the resource reservation information and future location information of the first UE may be transmitted via at least one of an SCI at a PHY layer, a MAC CE at a MAC layer, or higher layer information. The higher layer may be a network layer, a transport layer, or an application layer. The higher layer may utilize an RRC protocol.

[0045] In some embodiments, the resource reservation information and future location information of the first UE are included in a packet transmitted from the first UE to the second UE.

[0046] In some embodiments, the future location information of the first UE is represented as an ID of one of a plurality of zones in two or three dimensions. The plurality of zones may be configured by a network node or may be pre-configured in the first UE. In some embodiments, the future location information of the first UE is represented as two or more IDs of one of a plurality of zones in two or three dimensions, the two or more IDs of the zones including sub-zone IDs used for beamforming. The plurality of zones may be configured by a network node or may be pre-configured in the first UE. The first UE may be configured with the UE's UE ID or may be pre-configured in the first UE.

[0047] The method 900 includes receiving 906 a signal from a second UE including future location information of the second UE, the future location information of the second UE including an estimated second location of the second UE at a first time. In some embodiments, the signal received from the second UE may include a HARQ confirmation message. In some embodiments, the future location information of the second UE is transmitted via at least one of an SCI at a PHY layer, a MAC CE at a MAC layer, or higher layer information. The higher layer may utilize an RRC protocol.

[0048] In some embodiments, the future location information of the second UE is indicated as an ID of one of a plurality of zones in two or three dimensions, the plurality of zones may be configured by a network node or may be pre-configured in the first UE, and in some embodiments, the future location information of the second UE is indicated as two or more IDs of one of a plurality of zones in two or three dimensions, the two or more IDs of the zones including subzone IDs used for beamforming, the plurality of zones being configured or pre-configured.

[0049] The method 900 includes step 908 of determining one or more beams for transmission from the first UE based on the future location information of the second UE. In some embodiments, the first UE may perform beam training on one or more beams of the plurality of beams before determining the one or more beams. In some embodiments, the first UE may determine the beams for transmission based on a trigger signal received via a sidelink transmission. In some embodiments, the method 900 may further include at least one of the first UE transmitting to the second UE using the determined one or more beams or the first UE repeating the method 900 from step 902. In some embodiments, the first UE may determine one or more beams for transmission from the first UE within a period of time, the period including the first time. For example, the period of time may extend from step 906 to at least one of the first UE transmitting to the second UE using the determined one or more beams or the first UE repeating the method 900 from step 902.

[0050] In some embodiments, the future location information of the first UE is first future location information of the first UE, and the first UE may further transmit a packet to the second UE using the determined one or more beams. The packet may include second future location information of the first UE. The second future location information of the first UE may include an estimated third location of the first UE at a second time, which is after the first time. The estimated third location may be the same as or different from the estimated first location or the estimated second location. Also, the steps of method 900 may continue by repeating method 900 from step 902.

[0051] 10 is a flowchart illustrating a method 1000 for sidelink beam maintenance in sidelink communications, consistent with some embodiments of the present disclosure. Method 1000 may be performed by an Rx UE in sidelink communications, such as the Rx UEs of FIGS. 6 and 8.

[0052] The method 1000 includes receiving 1002, by a second UE, resource reservation information and future location information for the first UE from the first UE, where the future location information for the first UE includes an estimated first location of the first UE at a first time after the current time. In some embodiments, the resource reservation information and future location information for the first UE may be included in a packet transmitted from the first UE to the second UE.

[0053] In some embodiments, the future location information of the first UE may be represented as an ID of one of a plurality of zones in two or three dimensions. The plurality of zones may be configured by a network node or pre-configured in the first UE. In some embodiments, the future location information of the first UE may be represented as two or more IDs of one of a plurality of zones in two or three dimensions, the two or more IDs of the zones including subzone IDs used for beamforming. The plurality of zones may be configured by a network node or pre-configured in the first UE.

[0054] The method 1000 includes transmitting 1004 a signal to the first UE in response to receiving the resource reservation information and the future location information of the first UE, the signal including the future location information of the second UE, the future location information of the second UE including an estimated second location of the second UE at a first time. The second UE may determine the estimated second location of the second UE at the first time based on at least one of a current location of the second UE, a velocity of the second UE, an orientation of the second UE, or a planned trajectory of the second UE. In some embodiments, the signal transmitted to the first UE may include a HARQ confirmation message.

[0055] In some embodiments, the future location information of the second UE is transmitted via at least one of an SCI at a PHY layer, a MAC CE at a MAC layer, or higher layer information. The higher layer may utilize an RRC protocol. In some embodiments, the future location information of the second UE is transmitted using a low frequency band (e.g., FR1). In some embodiments, the future location information of the second UE is transmitted using a high frequency band (e.g., mmWave frequency band).

[0056] In some embodiments, the future location information of the second UE is indicated as an ID of one of a plurality of zones in two or three dimensions. The plurality of zones may be configured or pre-configured. In some embodiments, the future location information of the second UE is indicated as two or more IDs of one of a plurality of zones in two or three dimensions, the two or more IDs of the zones including subzone IDs used for beamforming. The plurality of zones may be configured or pre-configured.

[0057] Method 1000 includes step 1006 of determining one or more beams for reception by the second UE based on the future location information of the first UE. In some embodiments, method 900 may further include at least one of the second UE receiving the determined one or more beams from the first UE or the second UE repeating method 1000 from step 1002. In some embodiments, the second UE may determine one or more beams for reception by the second UE within a period of time, the period of time including the first time. For example, the period of time may extend from step 1004 to at least one of the second UE receiving the determined one or more beams from the first UE or the second UE repeating method 1000 from step 1002. In some embodiments, the second UE may perform beam training on one or more beams of the plurality of beams before determining the one or more beams.

[0058] In some embodiments, the second UE may receive a packet from the first UE using the determined beam or beams. In some embodiments, the future location information of the first UE is first future location information of the first UE, and the packet may include second future location information of the first UE. The second future location information of the first UE may include an estimated third location of the first UE at a second time, which is later than the first time. The estimated third location may be the same as or different from the estimated first location or the estimated second location. Additionally, the steps of method 1000 may be performed by repeating the method from step 1002. It can be continued.

[0059] FIG. 11 is a block diagram of a UE 1100 consistent with some embodiments of the present disclosure. For example, each of the Tx UE and Rx UE of FIGS. 6 and 8 may be in the form of a UE 1100. The UE 1100 may be mounted in a moving vehicle or at a fixed location. The UE 1100 may take any form, including, but not limited to, a vehicle, a vehicle-mounted component, a roadside unit, a laptop computer, a wireless terminal including a mobile phone, a wireless handheld device, or a wireless personal device, or any other form. Referring to FIG. 11, the UE 1100 may include an antenna 1102 that may be used to transmit or receive electromagnetic signals to or from a base station or other UEs. The antenna 1102 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 1102 may include multiple (e.g., tens or hundreds) antenna elements and may enable multi-antenna functionality such as beamforming. In some embodiments, the antenna 1102 is a single antenna. The antenna 1102 can be an FR1 antenna or an FR2 antenna.

[0060] The UE 1100 may include a transceiver 1104 coupled to an antenna 1102. The transceiver 1104 may be a wireless transceiver at the UE 1100 and may communicate bidirectionally with a base station or other UEs. For example, the transceiver 1104 may receive / transmit wireless signals to / from a base station via downlink / uplink communication. The transceiver 1104 may receive / transmit wireless signals to / from another UE or a roadside unit via sidelink communication. The transceiver 1104 may include a modem for modulating packets and providing the modulated packets to the antenna 1102 for transmission, and for demodulating packets received from the antenna 1102.

[0061] The UE 1100 may include memory 1106. The memory 1106 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 wireless technologies such as infrared, radio, and microwave. The media may be transmitted from a remote source (e.g., a website, a server, etc.) using a medium such as coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave. Combinations of the above examples are also within the scope of computer-readable media.

[0062] The memory 1106 may store information related to the identity of the UE 1100 and signals and / or data received by the antenna 1102. The memory 1106 may store post-processed signals and / or data. The memory 1106 may store computer-readable program instructions, mathematical models, and algorithms used for signal processing in the receiver 1104 and calculations in the processor 1108. The memory 1106 may further store computer-readable program instructions for execution by the processor 1108 to operate the UE 1100 to perform various functions described in this disclosure. In some examples, the memory 1106 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 1106 includes both an LTE SL module and an NR SL module. In some embodiments, the memory 1106 includes only an NR SL module. In some embodiments, the memory 1106 includes only an LTE SL module.

[0063] 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).

[0064] The UE 1100 may include a processor 1108, which may include hardware devices having processing capabilities. The processor 1108 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 general-purpose processors include, but are not limited to, a microprocessor, any conventional processor, controller, microcontroller, or state machine. In some embodiments, the processor 1108 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 1108 may receive downlink or sidelink signals from the transceiver 1104 and further process those signals. The processor 1108 may receive data packets from the transceiver 1104 and further process those packets. In some embodiments, the processor 1108 may be configured to operate memory using a memory controller. In some embodiments, the memory controller may be integrated into the processor 1108. The processor 1108 may be configured to execute computer-readable instructions stored in a memory (e.g., memory 1106) to cause the UE 1100 to perform various functions.

[0065] The UE 1100 may include a global positioning system (GPS) 1110. The GPS 1110 may be used to enable location-based services or other services based on the geographic location of the UE 1100 and / or synchronization between UEs. The GPS 1110 receives a global navigation satellite system (GNSS) signal from a single satellite or multiple satellites via an antenna 1102. navigation satellite systems) signals and can provide the geographic location of the UE 1100 (e.g., the coordinates of the UE 1100). In some embodiments, the GPS 1110 is omitted. In some embodiments, a timer is included.

[0066] The UE 1100 may include input / output (I / O) devices 1112 that can be used to communicate the results of signal processing and calculations to a user or another device. The I / O devices 1112 may include a user interface, including a display and input devices for sending user commands to the processor 1108. The display may be configured to display the status of signal reception at the UE 1100, data stored in the memory 1106, 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.

[0067] The UE 1100 may further include a machine interface 1114, such as an electrical bus, that connects the transceiver 1104, the memory 1106, the processor 1108, the GPS 1110, and the I / O device 1112.

[0068] In some embodiments, the UE 1100 may be a transmitter UE (e.g., a first UE) in sidelink communications (e.g., the Tx UE in FIGS. 6 and 8) and may be configured or programmed to perform sidelink beam maintenance in sidelink communications. The processor 1108 may be configured or programmed to execute instructions stored in the memory 1106 for: obtaining resource reservation information and future location information for the first UE, where the future location information for the first UE includes an estimated first location of the first UE at a first time after the current time; transmitting the resource reservation information and future location information for the first UE to a second UE; receiving a signal from the second UE including the future location information of the second UE, where the future location information for the second UE includes an estimated second location of the second UE at the first time; and determining one or more beams for transmission from the first UE based on the future location information of the second UE.

[0069] In some embodiments, the UE 1100 may transmit sidelink communications (e.g., the The processor 1108 may be a receiver UE (e.g., a second UE) in a sidelink communication system (Rx UE) and may be configured or programmed to perform sidelink beam maintenance in sidelink communications. The processor 1108 may be configured or programmed to execute instructions stored in the memory 1106 for: receiving, from the first UE, resource reservation information and future location information of the first UE, where the future location information of the first UE includes an estimated first location of the first UE at a first time after the current time; transmitting a signal to the first UE in response to receiving the resource reservation information and the future location information of the first UE, where the signal includes future location information of the second UE, where the future location information of the second UE includes an estimated second location of the second UE at the first time; and determining one or more beams for reception by the second UE based on the future location information of the first UE.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] 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.

[0078] 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.

[0079] 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.

[0080] 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.

[0081] Item 1. A first user equipment (UE) for maintaining a sidelink beam in sidelink communications, the first UE comprising: a memory for storing instructions; and a processor configured to execute instructions stored in a memory, the instructions comprising: Obtaining resource reservation information and future location information of a first UE, where the future location information of the first UE includes an estimated first location of the first UE at a first time after a current time; Sending resource reservation information and future location information of the first UE to a second UE; receiving a signal from a second UE including future location information of the second UE, the future location information of the second UE including an estimated second location of the second UE at a first time; and, and determining one or more beams for transmission from the first UE based on future location information of the second UE.

[0082] Clause 2. The first UE of clause 1, wherein one or more beams are determined for transmission from the first UE within a period of time, the period of time including a first time.

[0083] Item 3. The processor is further configured to execute instructions stored in the memory, the instructions comprising: A first UE as described in paragraph 1, which is for performing beam training on one or more beams of a plurality of beams before determining one or more beams for transmission from the first UE.

[0084] Item 4. The processor is further configured to execute instructions stored in the memory, the instructions comprising: 10. The first UE of claim 1, for transmitting a packet to a second UE using the determined one or more beams.

[0085] Clause 5. The first UE of clause 4, wherein the future location information of the first UE is first future location information of the first UE, the packet includes second future location information of the first UE, the second future location information of the first UE includes an estimated third location of the first UE at a second time after the first time, and the estimated third location is the same as or different from the estimated first location or the estimated second location.

[0086] Item 6. In obtaining the resource reservation information and future location information of the first UE, 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 is configured to determine an estimated first position of the first UE at a first time based on at least one of a current position of the first UE, a velocity of the first UE, an orientation of the first UE, or a planned trajectory of the first UE.

[0087] Clause 7. The first UE of clause 1, wherein the resource reservation information and future location information of the first UE are transmitted via at least one of sidelink control information (SCI) at the physical layer, a medium access control (MAC) control element (CE) at the MAC layer, or higher layer information.

[0088] Clause 8. The first UE of clause 1, wherein the resource reservation information and future location information of the first UE are transmitted using FR1.

[0089] Clause 9. The first UE of clause 1, wherein the resource reservation information and future location information of the first UE are transmitted using a millimeter wave frequency band.

[0090] Clause 10. The first UE of clause 1, wherein the future location information of the second UE is transmitted via at least one of an SCI at a physical layer, a MAC CE at a MAC layer, or higher layer information.

[0091] Clause 11. The first UE of clause 1, wherein the resource reservation information and future location information of the first UE are included in a packet transmitted from the first UE to the second UE.

[0092] Clause 12. The future location information of the first UE is indicated as identification information (ID) of one of multiple zones in two or three dimensions, and the multiple zones are configured or pre-defined. 2. The first UE of claim 1, configured

[0093] Clause 13. The first UE of clause 1, wherein the future location information of the first UE is indicated as two or more IDs of a zone among a plurality of zones in two or three dimensions, the two or more IDs of the zone including a subzone ID used for beamforming, and the plurality of zones are configured or pre-configured.

[0094] Clause 14. The first UE of clause 1, wherein the future location information of the second UE is indicated as an ID of one of a plurality of zones in two or three dimensions, the plurality of zones being configured or pre-configured.

[0095] Clause 15. The first UE of clause 1, wherein the future location information of the second UE is indicated as two or more IDs of a zone of a plurality of zones in two or three dimensions, the two or more IDs of the zone including a subzone ID used for beamforming, and the plurality of zones are configured or pre-configured.

[0096] Clause 16. The first UE of clause 1, wherein the processor is further configured to execute instructions stored in the memory, the instructions being for receiving a trigger signal via a sidelink transmission, and determining one or more beams for transmission from the first UE based on the trigger signal.

[0097] Clause 17. The first UE of clause 1, wherein the signal received from the second UE includes a hybrid automatic repeat request (HARQ) confirmation message.

[0098] Item 18. A second user equipment (UE) for maintaining a sidelink beam in sidelink communications, the second UE comprising: a memory for storing instructions; and a processor configured to execute instructions stored in a memory, the instructions comprising: receiving, from a first UE, resource reservation information and future location information of the first UE, the future location information of the first UE including an estimated first location of the first UE at a first time after the current time; transmitting a signal to the first UE in response to receiving the resource reservation information and the future location information of the first UE, the signal including the future location information of the second UE, the future location information of the second UE including an estimated second location of the second UE at the first time; and determining one or more beams for reception by the second UE based on the future location information of the first UE.

[0099] Clause 19. The second UE of clause 18, wherein one or more beams are determined for reception by the second UE within a period of time, the period of time including the first time.

[0100] Item 20. The processor is further configured to execute instructions stored in the memory, the instructions comprising: A second UE as described in clause 18, which is for performing beam training on one or more beams of the plurality of beams before determining one or more beams for reception by the second UE.

[0101] Item 21. The processor is further configured to execute instructions stored in the memory, the instructions comprising: 19. The second UE of claim 18, wherein the second UE is for receiving a packet from the first UE using the determined one or more beams.

[0102] Clause 22. The second UE of clause 21, wherein the future location information of the first UE is first future location information of the first UE, the packet includes second future location information of the first UE, the second future location information of the first UE includes an estimated third location of the first UE at a second time after the first time, and the estimated third location is the same as or different from the estimated first location or the estimated second location.

[0103] Item 23. The processor is further configured to execute instructions stored in the memory, the instructions comprising: 19. The second UE of claim 18, wherein the second UE is configured to determine an estimated second position of the second UE at a first time based on at least one of a current position of the second UE, a velocity of the second UE, an orientation of the second UE, or a planned trajectory of the second UE.

[0104] Clause 24. The second UE of clause 18, wherein the future location information of the second UE is transmitted via at least one of sidelink control information (SCI) at the physical layer, a medium access control (MAC) control element (CE) at the MAC layer, or higher layer information.

[0105] Clause 25. The second UE of clause 18, wherein the future location information of the second UE is transmitted using FR1.

[0106] Clause 26. The second UE of clause 18, wherein the future location information of the second UE is transmitted using a millimeter wave frequency band.

[0107] Clause 27. The second UE of clause 18, wherein the resource reservation information and future location information of the first UE are included in a packet transmitted from the first UE to the second UE.

[0108] Clause 28. The second UE of clause 18, wherein the future location information of the first UE is indicated as an identification (ID) of one of a plurality of zones in two or three dimensions, and the plurality of zones are configured or pre-configured.

[0109] Clause 29. The second UE of clause 18, wherein the future location information of the first UE is indicated as two or more IDs of a zone of a plurality of zones in two or three dimensions, the two or more IDs of the zone including a subzone ID used for beamforming, and the plurality of zones are configured or pre-configured.

[0110] Clause 30. The second UE of clause 18, wherein the future location information of the second UE is indicated as an ID of one of a plurality of zones in two or three dimensions, and the plurality of zones is configured or pre-configured.

[0111] Clause 31. The second UE of clause 18, wherein the future location information of the second UE is indicated as two or more IDs of a zone of a plurality of zones in two or three dimensions, the two or more IDs of the zone including a subzone ID used for beamforming, and the plurality of zones are configured or pre-configured.

[0112] 32. A method for maintaining a sidelink beam in sidelink communications, comprising: acquiring, by a first user equipment (UE), resource reservation information and future location information of the first UE, wherein the future location information of the first UE includes an estimated first location of the first UE at a first time after a current time; Sending resource reservation information and future location information of the first UE to a second UE; receiving a signal from a second UE including future location information of the second UE, the future location information of the second UE including an estimated second location of the second UE at a first time; and determining one or more beams for transmission from the first UE based on future location information of the second UE.

[0113] Clause 33. The method of clause 32, wherein one or more beams are determined for transmission from a first UE within a period of time, the period of time including a first time.

[0114] Clause 34. The method of clause 32, further comprising performing beam training on one or more beams of the plurality of beams before determining one or more beams for transmission from the first UE.

[0115] Clause 35. The method of clause 32, further comprising transmitting a packet to a second UE using the determined one or more beams.

[0116] Clause 36. The method of clause 35, wherein the future location information of the first UE is first future location information of the first UE, the packet includes second future location information of the first UE, the second future location information of the first UE includes an estimated third location of the first UE at a second time after the first time, and the estimated third location is the same as or different from the estimated first location or the estimated second location.

[0117] Clause 37. Obtaining resource reservation information and future location information of a first UE includes: 33. The method of clause 32, further comprising determining an estimated first position of the first UE at the first time based on at least one of a current position of the first UE, a velocity of the first UE, an orientation of the first UE, or a planned trajectory of the first UE.

[0118] Clause 38. The method of clause 32, wherein the resource reservation information and future location information of the first UE are transmitted via at least one of sidelink control information (SCI) at the physical layer, a medium access control (MAC) control element (CE) at the MAC layer, or higher layer information.

[0119] Clause 39. The method of clause 32, wherein the resource reservation information and future location information of the first UE are transmitted using FR1.

[0120] Clause 40. The method of clause 32, wherein the resource reservation information and future location information of the first UE are transmitted using a millimeter wave frequency band.

[0121] Clause 41. The method of clause 32, wherein the future location information of the second UE is transmitted via at least one of an SCI at the physical layer, a MAC CE at the MAC layer, or higher layer information.

[0122] Clause 42. The method of clause 32, wherein the resource reservation information and future location information of the first UE are included in a packet transmitted from the first UE to the second UE.

[0123] Clause 43. The method of clause 32, wherein the future location information of the first UE is indicated as an identification (ID) of one of a plurality of zones in two or three dimensions, and the plurality of zones is configured or pre-configured.

[0124] Clause 44. The future location information of the first UE is represented as two or more IDs of one of a plurality of zones in two or three dimensions, and the two or more IDs of the zones are 33. The method of clause 32, wherein a plurality of zones are configured or pre-configured, including subzone IDs used in the formation.

[0125] Clause 45. The method of clause 32, wherein the future location information of the second UE is indicated as an ID of one of a plurality of zones in two or three dimensions, the plurality of zones being configured or pre-configured.

[0126] Clause 46. The method of clause 32, wherein the future location information of the second UE is indicated as two or more IDs of a zone of a plurality of zones in two or three dimensions, the two or more IDs of the zone including subzone IDs used for beamforming, and the plurality of zones are configured or pre-configured.

[0127] Clause 47. Further including receiving a trigger signal via a sidelink transmission; 33. The method of clause 32, wherein determining one or more beams for transmission from the first UE is based on a trigger signal.

[0128] Clause 48. The method of clause 32, wherein the signal received from the second UE includes a hybrid automatic repeat request (HARQ) confirmation message.

[0129] 49. A method for maintaining a sidelink beam in sidelink communications, comprising: receiving, by a second user equipment (UE), from a first UE, resource reservation information and future location information of the first UE, wherein the future location information of the first UE includes an estimated first location of the first UE at a first time after the current time; transmitting a signal to the first UE in response to receiving the resource reservation information and the future location information of the first UE, the signal including the future location information of the second UE, the future location information of the second UE including an estimated second location of the second UE at the first time; and determining one or more beams for reception by the second UE based on the future position information of the first UE.

[0130] Clause 50. The method of clause 49, wherein one or more beams are determined for reception by the second UE within a period of time, the period of time including the first time.

[0131] Clause 51. The method of clause 49, further comprising performing beam training on one or more beams of the plurality of beams before determining one or more beams for reception by the second UE.

[0132] Clause 52. The method of clause 49, further comprising receiving a packet from the first UE using the determined one or more beams.

[0133] Clause 53. The method of clause 52, wherein the future location information of the first UE is first future location information of the first UE, the packet includes second future location information of the first UE, the second future location information of the first UE includes an estimated third location of the first UE at a second time after the first time, and the estimated third location is the same as or different from the estimated first location or the estimated second location.

[0134] Clause 54. The method of clause 49, further comprising determining an estimated second position of the second UE at the first time based on at least one of a current position of the second UE, a velocity of the second UE, an orientation of the second UE, or a planned trajectory of the second UE.

[0135] Clause 55. The method of clause 49, wherein the future location information of the second UE is transmitted via at least one of sidelink control information (SCI) at the physical layer, a medium access control (MAC) control element (CE) at the MAC layer, or higher layer information.

[0136] Clause 56. The method of clause 49, wherein the future location information of the second UE is transmitted using FR1.

[0137] Clause 57. The method of clause 49, wherein the future location information of the second UE is transmitted using a millimeter wave frequency band.

[0138] Clause 58. The method of clause 49, wherein the resource reservation information and future location information of the first UE are included in a packet transmitted from the first UE to the second UE.

[0139] Clause 59. The method of clause 49, wherein the future location information of the first UE is indicated as an identification (ID) of one of a plurality of zones in two or three dimensions, and the plurality of zones is configured or pre-configured.

[0140] Clause 60. The method of clause 49, wherein the future location information of the first UE is indicated as two or more IDs of a zone of a plurality of zones in two or three dimensions, the two or more IDs of the zone including subzone IDs used for beamforming, and the plurality of zones are configured or pre-configured.

[0141] Clause 61. The method of clause 49, wherein the future location information of the second UE is indicated as an ID of one of a plurality of zones in two or three dimensions, the plurality of zones being configured or pre-configured.

[0142] Clause 62. The method of clause 49, wherein the future location information of the second UE is indicated as two or more IDs of a zone of a plurality of zones in two or three dimensions, the two or more IDs of the zone including subzone IDs used for beamforming, and the plurality of zones are configured or pre-configured.

[0143] Clause 63. A non-transitory computer-readable medium storing instructions executable by one or more processors of a first user equipment (UE) in a sidelink communications network to perform a method, the method comprising: Obtaining resource reservation information and future location information of a first UE, where the future location information of the first UE includes an estimated first location of the first UE at a first time after a current time; Sending resource reservation information and future location information of the first UE to a second UE; receiving a signal from a second UE including future location information of the second UE, the future location information of the second UE including an estimated second location of the second UE at a first time; and determining one or more beams for transmission from the first UE based on the future position information of the second UE.

[0144] Clause 64. A non-transitory computer-readable medium storing instructions executable by one or more processors of a second user equipment (UE) in sidelink communication to perform a method, the method comprising: receiving, from a first UE, resource reservation information and future location information of the first UE, the future location information of the first UE including an estimated first location of the first UE at a first time after the current time; transmitting a signal to the first UE in response to receiving the resource reservation information and the future location information of the first UE, the signal including the future location information of the second UE, the future location information of the second UE including an estimated second location of the second UE at the first time; and determining one or more beams for reception by the second UE based on the future position information of the first UE.

Claims

1. 1. A first user equipment (UE) for maintaining a sidelink beam in sidelink communication, the first UE comprising: a memory for storing instructions; and a processor configured to execute the instructions stored in the memory; The instruction: obtaining resource reservation information and future location information of the first UE, the future location information of the first UE including an estimated first location of the first UE at a first time after a current time; transmitting the resource reservation information and the future location information of the first UE to a second UE; receiving a signal from the second UE including future location information of the second UE, the future location information of the second UE including an estimated second location of the second UE at the first time; determining one or more beams for transmission from the first UE based on the future location information of the second UE; a first user equipment (UE) for performing

2. the one or more beams for transmission from the first UE within a period of time are determined, the period of time including the first time; The first user equipment (UE) of claim 1.

3. The processor is further configured to execute the instructions stored in the memory, the instructions comprising: performing beam training on one or more beams among a plurality of beams before determining the one or more beams for transmission from the first UE; The first user equipment (UE) of claim 1.

4. The processor is further configured to execute the instructions stored in the memory, the instructions comprising: and transmitting a packet to the second UE using the determined one or more beams. The first user equipment (UE) of claim 1.

5. the future location information of the first UE is first future location information of the first UE, the packet includes second future location information of the first UE, the second future location information of the first UE includes an estimated third location of the first UE at a second time after the first time, and the estimated third location is the same as or different from the estimated first location or the estimated second location; A first user equipment (UE) according to claim 4.

6. In obtaining the resource reservation information and the future location information of the first UE, the processor is further configured to execute the instructions stored in the memory, the instructions comprising: and determining the estimated first position of the first UE at the first time based on at least one of a current location of the first UE, a velocity of the first UE, an orientation of the first UE, or a planned trajectory of the first UE. The first user equipment (UE) of claim 1.

7. the resource reservation information and the future location information of the first UE are transmitted via at least one of a sidelink control information (SCI) at a physical layer, a medium access control (MAC) control element (CE) at a MAC layer, or higher layer information; The first user equipment (UE) of claim 1.

8. the resource reservation information and the future location information of the first UE are transmitted using FR1; The first user equipment (UE) of claim 1.

9. the resource reservation information and the future location information of the first UE are transmitted using a millimeter wave frequency band; The first user equipment (UE) of claim 1.

10. the future location information of the second UE is transmitted via at least one of an SCI at a physical layer, a MAC CE at a MAC layer, or higher layer information; The first user equipment (UE) of claim 1.

11. The resource reservation information and the future location information of the first UE are included in a packet transmitted from the first UE to the second UE. The first user equipment (UE) of claim 1.

12. the future location information of the first UE is indicated as an identification (ID) of one of a plurality of zones in two or three dimensions, the plurality of zones being configured or pre-configured; The first user equipment (UE) of claim 1.

13. the future location information of the first UE is represented as two or more IDs of a zone among a plurality of zones in two or three dimensions, the two or more IDs of the zone including subzone IDs used for beamforming, and the plurality of zones are configured or pre-configured; The first user equipment (UE) of claim 1.

14. the future location information of the second UE is indicated as an ID of one of a plurality of zones in two or three dimensions, the plurality of zones being configured or pre-configured; The first user equipment (UE) of claim 1.

15. the future location information of the second UE is represented as two or more IDs of a zone among a plurality of zones in two or three dimensions, the two or more IDs of the zone including subzone IDs used for beamforming, and the plurality of zones are configured or pre-configured; The first user equipment (UE) of claim 1.

16. the processor is further configured to execute the instructions stored in the memory, the instructions being for receiving a trigger signal via a sidelink transmission, and determining the one or more beams for transmission from the first UE based on the trigger signal. The first user equipment (UE) of claim 1.

17. the signal received from the second UE includes a Hybrid Automatic Repeat Request (HARQ) confirmation message. The first user equipment (UE) of claim 1.

18. A second user equipment (UE) for maintaining a sidelink beam in sidelink communication, the second UE comprising: a memory for storing instructions; and a processor configured to execute the instructions stored in the memory, the instructions comprising: receiving, from a first UE, resource reservation information and future location information of the first UE, the future location information of the first UE including an estimated first location of the first UE at a first time after a current time; transmitting a signal to the first UE in response to receiving the resource reservation information and the future location information of the first UE, the signal including future location information of the second UE, the future location information of the second UE including an estimated second location of the second UE at the first time; determining one or more beams for reception by the second UE based on the future location information of the first UE; a second user equipment (UE) for performing the

19. the one or more beams for reception by the second UE within a period of time are determined, the period of time including the first time.

20. A second user equipment (UE) according to claim 18.

20. 1. A method for maintaining a sidelink beam in sidelink communications, comprising: acquiring, by a first user equipment (UE), resource reservation information and future location information of the first UE, the future location information of the first UE including an estimated first location of the first UE at a first time after a current time; transmitting the resource reservation information and the future location information of the first UE to a second UE; receiving a signal from the second UE including future location information of the second UE, the future location information of the second UE including an estimated second location of the second UE at the first time; determining one or more beams for transmission from the first UE based on the future location information of the second UE; A method comprising:

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