Resource mapping from sidelink CSI-RS to psfch for beam reporting

Abstract

Disclosed are methods, systems, and computer-readable medium to perform operations including: obtaining a sidelink channel state information reference signal (CSI-RS) transmitted by a UE, determining, based on a mapping rule, one or more physical sidelink feedback channel (PSFCH) resources for beam reporting, wherein the mapping rule specifies a mapping between one or more resources for the sidelink CSI-RS and the one or more PSFCH resources, and transmitting a beam report to the UE using the determined one or more PSFCH resources.

Description

Attorney Docket No. 56990-0012W01 / P64549WO1RESOURCE MAPPING FROM SIDELINK CSI-RS TO PSFCH FOR BEAM REPORTINGCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to and the benefit of U.S. Provisional Patent Application No. 63 / 605,379, filed December 1, 2023, the entire content of which is incorporated herein by reference.BACKGROUND

[0002] Wireless communication networks provide integrated communication platforms and telecommunication services to wireless user devices. Example telecommunication services include telephony, data (e.g., voice, audio, and / or video data), messaging, and / or other services. The wireless communication networks have wireless access nodes that exchange wireless signals with the wireless user devices using wireless network protocols, such as protocols described in various telecommunication standards promulgated by the Third Generation Partnership Project (3GPP). Example wireless communication networks include time division multiple access (TDMA) networks, frequency-division multiple access (FDMA) networks, orthogonal frequency-division multiple access (OFDMA) networks, Long Term Evolution (LTE), and Fifth Generation New Radio (5G NR). The wireless communication networks facilitate mobile broadband service using technologies such as OFDM, multiple input multiple output (MIMO), advanced channel coding, massive MIMO, beamforming, and / or other features.Attorney Docket No. 56990-0012W01 / P64549WO1SUMMARY

[0003] The present disclosure describes techniques for determining resources, such as physical sidelink feedback channel (PSFCH) resources, to be used for beam reporting. In particular, a mapping between sidelink channel state information reference signal (CSI-RS) resources and PSFCH resources is defined to enable PSFCH-based beam reporting. The present disclosure also provides techniques for selecting a transmit beam and a receive beam for beam reporting over PSFCH. In addition, definitions of a channel busy ratio (CBR) and channel occupancy ratio (CR) for sidelink beam-based transmission are described.

[0004] In general, in a first aspect, a method includes: obtaining a sidelink channel state information reference signal (CSI-RS) transmitted by a user equipment (UE), determining, based on a mapping rule, one or more physical sidelink feedback channel (PSFCH) resources for beam reporting, where the mapping rule specifies a mapping between one or more resources for the sidelink CSI-RS and the one or more PSFCH resources, and causing transmission of a beam report to the UE using the determined one or more PSFCH resources.

[0005] In a second aspect combinable with the first aspect, the mapping rule includes at least one of a time domain mapping rule or a frequency domain mapping rule.

[0006] In a third aspect combinable with the first or second aspects, the mapping rule specifies a number of slots between the sidelink CSI-RS and the one or more PSFCH resources.

[0007] In a fourth aspect combinable with any of the preceding aspects, determining, based on the mapping rule, the one or more PSFCH resources for beam reporting includes: indexing one or more sidelink CSI-RS resource sets; indexing one or more PSFCH physical resource blocks (PRBs); associating each of the sidelink CSI-RS resource sets in a slot with a number of the one or more PSFCH PRBs; and for each of the one or more sidelink CSI-RS resource sets, associating each sidelink CSI-RS resource in the respective sidelink CSI-RS resource set with at least one of the one or more PSFCH PRBs; and indexing PSFCH resources among the at least one of the one or more PSFCH PRBs.

[0008] In a fifth aspect combinable with the fourth aspect, the one or more sidelink CSI-RS resource sets are indexed according to a slot index first and sub-channel index second rule, or a sub-channel index first and a slot index second rule.

[0009] In a sixth aspect combinable with the fourth or fifth aspects, the number of the one or more PRBs associated with each of the sidelink CSI-RS resource sets in a slot comprises aAttorney Docket No. 56990-0012W01 / P64549WO1 number of the one or more PRBs divided by a number of the one or more sidelink CSI-RS resource sets.

[0010] In a seventh aspect combinable with any of the fourth through sixth aspects, each sidelink CSI-RS resource in the respective sidelink CSI-RS resource set is associated with the at least one of the one or more PSFCH PRBs according to a contiguous mapping scheme or an interlaced mapping scheme.

[0011] In an eighth aspect combinable with any of the fourth through seventh aspects, the PSFCH resources are indexed among the at least one of the one or more PSFCH PRBs according to a PRB index first and cyclic shift index second rule, or a cyclic shift index first and a PRB index second rule.

[0012] In a ninth aspect combinable with any of the preceding aspects, operations of the method include selecting a beam for transmission of the beam report to the UE; and transmitting the beam report to the UE using the selected beam.

[0013] In a tenth aspect combinable with the ninth aspect, the selected beam includes: a beam corresponding to a receive beam of the UE, a beam corresponding to a transmit beam used for transmission of a hybrid automatic repeat request acknowledgement (HARQ-ACK) over PSFCH to the UE, a beam selected as part of a beam sweeping process over multiple slots, or a wide beam.

[0014] In general, in an eleventh aspect, a method includes: causing transmission of a sidelink channel state information reference signal (CSI-RS) to a user equipment (UE), determining, based on a mapping rule, one or more physical sidelink feedback channel (PSFCH) resources for beam reporting, where the mapping rule specifies a mapping between one or more resources for the sidelink CSI-RS and the one or more PSFCH resources, and receiving a beam report from the UE using the determined one or more PSFCH resources.

[0015] In a twelfth aspect combinable with the eleventh aspect, the mapping rule includes at least one of a time domain mapping rule or a frequency domain mapping rule.

[0016] In a thirteenth aspect combinable with the eleventh or twelfth aspects, the mapping rule specifies a number of slots between the sidelink CSI-RS and the one or more PSFCH resources.

[0017] In a fourteenth aspect combinable with any of the eleventh through thirteenth aspects, determining, based on the mapping rule, the one or more PSFCH resources for beam reportingAttorney Docket No. 56990-0012W01 / P64549WO1 includes: indexing one or more sidelink CSI-RS resource sets; indexing one or more PSFCH physical resource blocks (PRBs); associating each of the sidelink CSI-RS resource sets in a slot with a number of the one or more PSFCH PRBs; and for each of the one or more sidelink CSI-RS resource sets, associating each sidelink CSI-RS resource in the respective sidelink CSI- RS resource set with at least one of the one or more PSFCH PRBs; and indexing PSFCH resources among the at least one of the one or more PSFCH PRBs.

[0018] In a fifteenth aspect combinable with the fourteenth aspect, the one or more sidelink CSI-RS resource sets are indexed according to a slot index first and sub-channel index second rule, or a sub-channel index first and a slot index second rule.

[0019] In a sixteenth aspect combinable with the fourteenth or fifteenth aspects, the number of the one or more PRBs associated with each of the sidelink CSI-RS resource sets in a slot includes a number of the one or more PRBs divided by a number of the one or more sidelink CSI-RS resource sets.

[0020] In a seventeenth aspect combinable with any of the fourteenth through sixteenth aspects, each sidelink CSI-RS resource in the respective sidelink CSI-RS resource set is associated with the at least one of the one or more PSFCH PRBs according to a contiguous mapping scheme or an interlaced mapping scheme.

[0021] In an eighteenth aspect combinable with any of the fourteenth through seventeenth aspects, the PSFCH resources are indexed among the at least one of the one or more PSFCH PRBs according to a PRB index first and cyclic shift index second rule, or a cyclic shift index first and a PRB index second rule.

[0022] In a nineteenth aspect combinable with any of the eleventh through eighteenth aspects, operations of the method further include: selecting a beam for reception of the beam report from the UE; and receiving the beam report from the UE using the selected beam.

[0023] In a twentieth aspect combinable with the nineteenth aspect, the selected beam includes: a beam corresponding to a transmit beam of the UE, a beam corresponding to a receive beam used for reception of a hybrid automatic repeat request acknowledgement (HARQ-ACK) over PSFCH from the UE, or a wide beam.

[0024] In general, in a twenty-first aspect, a method includes: monitoring a resource pool associated with a sidelink interface between a first user equipment (UE) and a second UE; and based on the monitored resource pool, determining at least one of: a sidelink channel busy ratioAttorney Docket No. 56990-0012W01 / P64549WO1(SL CBR) for a particular receive beam of the first UE, or a sidelink channel occupancy ratio (SL CR) for a particular transmit beam of the first UE.

[0025] In a twenty-second aspect combinable with the twenty-first aspect, the resource pool includes at least one reference signal, beam reporting, or beam indication resource that is shared with at least one physical sidelink control channel (PSCCH) or physical sidelink shared channel (PSSCH) resource.

[0026] In a twenty -third aspect combinable with the twenty-first or twenty-second aspects, the at least one of the SL CBR or the SL CR is determined for reference signal, beam reporting, and beam indication, operations of the method further including: determining at least one of a second SL CBR or a second SL CR for physical sidelink control channel (PSCCH) and physical sidelink shared channel (PSSCH).

[0027] In a twenty -fourth aspect combinable with any of the twenty -first through twenty -third aspects, operations of the method further include: receiving a measurement window configuration; monitoring the resource pool according to the measurement window configuration; and determining the at least one of the SL CBR or the SL CR based on the monitoring of the resource pool according to the measurement window configuration.

[0028] In a twenty-fifth aspect combinable with the twenty-fourth aspect, the measurement window configuration is for reference signal, beam reporting, and beam indication, operations of the method further including: receiving a separate measurement window configuration for physical sidelink control channel (PSCCH) and physical sidelink shared channel (PSSCH).

[0029] In a twenty-sixth aspect combinable with any of the twenty-first through twenty -fifth aspect, the at least one of the SL CBR or SL CR is determined for reference signal, beam reporting, beam indication, physical sidelink control channel (PSCCH), and physical sidelink shared channel (PSSCH).

[0030] In a twenty-seventh aspect combinable with any of the twenty-first through twentysixth aspects, the particular receive beam of the first UE corresponds to a transmit beam for a sidelink received signal strength indicator (SL-RSSI).

[0031] In a twenty-eighth aspect combinable with any of the twenty-first through twentyseventh aspects, the particular transmit beam of the first UE corresponds to a desired transmit beam for the first UE.Attorney Docket No. 56990-0012W01 / P64549WO1

[0032] In general, in a twenty-ninth aspect, one or more non-transitory computer storage mediums store instructions that, when executed by one or more processors, cause the one or more processors to perform the method of any preceding claim.

[0033] In general, in a thirtieth aspect, a system includes one or more processors and one or more storage devices storing instructions that, when executed by the one or more processors, cause the one or more processors to perform the method of any preceding claim.

[0034] In general, in a thirty-first aspect, an apparatus includes one or more processors configured to perform the method of any preceding claim.

[0035] In general, in a thirty-second aspect, one or more baseband processors are configured to perform the method of any preceding claim.Attorney Docket No. 56990-0012W01 / P64549WO1BRIEF DESCRIPTION OF THE FIGURES

[0036] FIG. 1 illustrates an example communication system that includes sidelink communications, according to some implementations.

[0037] FIG. 2 illustrates an example resource mapping between sidelink channel state information reference signal (CSI-RS) resources and physical sidelink feedback channel (PSFCH) resources for PSFCH-based beam reporting, according to some implementations.

[0038] FIG. 3 through FIG. 5 illustrate flowcharts of example methods, according to some implementations.

[0039] FIG. 6 illustrates an example user equipment (UE), according to some implementations.Attorney Docket No. 56990-0012W01 / P64549WO1DETAILED DESCRIPTION

[0040] In 3 GPP wireless telecommunication networks, a user equipment (UE) may communicate with another UE directly (e.g., without a radio access network as an intermediary) using what is referred to as sidelink communication. Although sidelink communication was initially developed for vehicle-to-everything (V2X) applications, there is growing interest to expand the applicability of sidelink to other use cases. To support this effort, enhanced sidelink operation on the frequency range 2 (FR2) licensed spectrum may be implemented. In particular, operations for the support of sidelink beam management in FR2, including initial beam-pairing, beam maintenance, and beam failure recovery, may be defined.

[0041] Sidelink beam management may use sidelink channel state information reference signal (CSI-RS) for sidelink beam maintenance. For beam reporting, either the physical sidelink feedback channel (PSFCH) or a sidelink medium access control (MAC) control element (CE) can be used. However, for such beam reporting, a rule, mapping, or other means for determining which PSFCH resources to use for PSFCH-based beam reporting may be required. Without such means for determining the PSFCH resources, a UE receiving a sidelink CSI-RS is unable to determine which PSFCH resources should be used to transmit a beam report. Similarly, the UE transmitting the sidelink CSI-RS would be unable to determine which PSFCH resources should be monitored to receive the beam report. To further facilitate beam reporting in this context, a mechanism for determining which transmit beam or receive beam to use for beam reporting over PSFCH may be used. In addition, support of enhanced beam reporting may define how the channel busy ratio (CBR) and channel occupancy ratio (CR) should be measured in sidelink beam-based transmission.

[0042] The present disclosure describes techniques for determining the PSFCH resources to use for beam reporting. In particular, a mapping between sidelink CSI-RS resources and PSFCH resources is defined to enable PSFCH-based beam reporting. Such a mapping can include a time domain mapping and / or a frequency domain mapping, as described herein. The present disclosure also provides techniques for selecting a transmit beam and a receive beam for beam reporting over PSFCH. In addition, definitions of CBR and CR for sidelink beambased transmission are described.

[0043] FIG. 1 illustrates an example communication system 100 that includes sidelink communications, according to some implementations. It is noted that the system of FIG. 1 isAttorney Docket No. 56990-0012W01 / P64549WO1 merely one example of a possible system, and that features of this disclosure may be implemented in other wireless communication systems.

[0044] The following description is provided for an example communication system that operates in conjunction with fifth generation (5G) networks as provided by 3GPP technical specifications. However, the example implementations are not limited in this regard and the described examples may apply to other networks that may benefit from the principles described herein, such as 3 GPP Long Term Evolution (LTE) networks, Wi-Fi networks, and the like. Furthermore, other types of communication standards are possible, including future 3 GPP systems (e.g., Sixth Generation (6G)), IEEE 802.16 protocols, or the like. While aspects may be described herein using terminology commonly associated with 5G NR, aspects of the present disclosure can be applied to other systems, such as 3G, 4G, and / or systems subsequent to 5G (e.g., 6G).

[0045] Frequency bands for 5G NR may be separated into at least two different frequency ranges. Frequency Range 1 (FR1) may include frequency bands operating in sub-6 GHz frequencies, some of which are bands that may be used by previous standards, and may potentially be extended to cover new spectrum offerings from 410 MHz to 7125 MHz. Frequency Range 2 (FR2) may include frequency bands from 24.25 GHz to 52.6 GHz. Bands in the millimeter wave (mmWave) range of FR2 may have smaller coverage but potentially higher available bandwidth than bands in the FR1.

[0046] As shown, the communication system 100 includes a number of user devices. More specifically, the communication system 100 includes two UEs 105 (UE 105-1 and UE 105-2 are collectively referred to as “UE 105” or “UEs 105”), two base stations 110 (base station 110-1 and base station 110-2 are collectively referred to as “base station 110” or “base stations 110”), two cells 115 (cell 115-1 and cell 115-2 are collectively referred to as “cell 115” or “cells 115”), and one or more servers 135 in a core network (CN) 140 that is connected to the Internet 145.

[0047] In some implementations, the UEs 105 can directly communicate with base stations 110 via links 120 (link 120-1 and link 120-2 are collectively referred to as “link 120” or “links 120”), which utilize a direct interface with the base stations referred to as a “Uu interface.” Each of the links 120 can represent one or more channels. The links 120 are illustrated as an air interface to enable communicative coupling, and can be consistent with cellular communication protocols, such as a GSM protocol, a CDMA network protocol, a UMTSAttorney Docket No. 56990-0012W01 / P64549WO1 protocol, a 3 GPP LTE protocol, an Advanced long term evolution (LTE-A) protocol, a LTE- based access to unlicensed spectrum (LTE-U), a 5G protocol, a NR protocol, an NR-based access to unlicensed spectrum (NR-U) protocol, and / or any of the other communications protocols discussed herein.

[0048] As shown, certain user devices may be able to conduct communications with one another directly, e.g., without an intermediary infrastructure device such as base station 110-1. In this example, UE 105-1 may conduct communications directly with UE 105-2. Similarly, the UE 105-2 may conduct communications directly with UE 105-1. Such peer-to-peer communications may utilize a “sidelink” interface such as a PC5 interface. In certain implementations, the PC5 interface supports direct cellular communication between user devices (e.g., between UEs 105), while the Uu interface supports cellular communications with infrastructure devices such as base stations. For example, the UEs 105 may use the PC5 interface for a radio resource control (RRC) signaling exchange between the UEs (also called PC5-RRC signaling). The PC5 / Uu interfaces are used only as an example, and PC5 as used herein may represent various other possible wireless communications technologies that allow for direct sidelink communications between user devices, while Uu in turn may represent cellular communications conducted between user devices and infrastructure devices, such as base stations.

[0049] In some implementations, the UEs 105 may be configured with parameters for communicating via the Uu interface and / or the sidelink interface. In some examples, the UEs 105 may be “pre-configured” with some parameters. In these examples, the parameters may be hardwired into the UEs 105 or coded into spec. Additionally and / or alternatively, the UEs 105 may receive the parameters from the one or more of the base stations 110.

[0050] To transmit / receive data to / from one or more base stations 110 or UEs 105, the UEs 105 may include a transmitter / receiver (or alternatively, a transceiver), memory, one or more processors, and / or other like components that enable the UEs 105 to operate in accordance with one or more wireless communications protocols and / or one or more cellular communications protocols. The UEs 105 may have multiple antenna elements that enable the UEs 105 to maintain multiple links 120 and / or sidelinks 125 to transmit / receive data to / from multiple base stations 110 and / or multiple UEs 105. For example, as shown in FIG. 1, UE 105-1 may connect with base station 110-1 via link 120 and simultaneously connect with UE 105-2 via sidelink 125.Attorney Docket No. 56990-0012W01 / P64549WO1

[0051] In some implementations, one or more sidelink radio bearers may be established on the sidelink 125. The sidelink radio bearers can include signaling radio bearers (SL-SRB) and / or data radio bearers (SL-DRB).

[0052] The PC5 interface may alternatively be referred to as a sidelink interface and may include one or more logical channels, including but not limited to a Physical Sidelink Control Channel (PSCCH), a Physical Sidelink Shared Channel (PSSCH), a Physical Sidelink Discovery Channel (PSDCH), a Physical Sidelink Broadcast Channel (PSBCH), Physical Sidelink Feedback Channel (PSFCH), and / or any other like communications channels. The PSFCH carries feedback related to the successful or failed reception of a sidelink transmission. The PSSCH can be scheduled by sidelink control information (SCI) carried in the sidelink PSCCH. In some examples, the sidelink interface can operate on an unlicensed spectrum (e.g., in the unlicensed 5 Gigahertz (GHz) and 6 GHz bands) or a (licensed) shared spectrum.

[0053] In one example, the sidelink interface implements vehicle-to-everything (V2X) communications. The V2X communications may, for example, adhere to 3GPP Cellular V2X (C-V2X) specifications, or to one or more other or subsequent standards whereby vehicles and other devices and network entities may communicate. V2X communications may utilize both long-range (e.g., cellular) communications as well as short- to medium -range (e.g., non- cellular) communications. Cellular-capable V2X communications may be called Cellular V2X (C-V2X) communications. C-V2X systems may use various cellular radio access technologies (RATs), such as 4GLTE or 5GNRRATs (orRATs subsequent to 5G, e.g., 6GRATs). Certain LTE standards usable in V2X systems may be called LTE-Vehicle (LTE-V) standards. As used herein in the context of V2X systems, and as defined above, the term “user devices” may refer generally to devices that are associated with mobile actors or traffic participants in the V2X system, e.g., mobile (able-to-move) communication devices such as vehicles, pedestrian user equipment (PUE) devices, and road side units (RSUs).

[0054] In some implementations, UEs 105 may be physical hardware devices capable of running one or more applications, capable of accessing network services via one or more radio links 120 with a corresponding base station 110 (also referred to as a “serving” base station), and capable of communicating with one another via sidelink 125. Link 120 may allow the UEs 105 to transmit and receive data from the base station 110 that provides the link 120. The sidelink 125 may allow the UEs 105 to transmit and receive data from one another. The sidelink 125 between the UEs 105 may include one or more channels for transmittingAttorney Docket No. 56990-0012W01 / P64549WO1 information from UE 105-1 to UE 105-2 and vice versa and / or between UEs 105 and UE-type RSUs and vice versa.

[0055] In some implementations, the base stations 110 are capable of communicating with one another over a backhaul connection 130 and may communicate with the one or more servers 135 within the CN 140 over another backhaul connection 133. The backhaul connections can be wired and / or wireless connections.

[0056] In some implementations, the UEs 105 are configured to use a resource pool for sidelink communications. A sidelink resource pool defines the time-frequency resources used for sidelink communications, and may be divided into multiple time slots, frequency channels, and frequency sub-channels. In some examples, the UEs 105 are synchronized and perform sidelink transmissions aligned with slot boundaries. A UE may be expected to select several slots and sub-channels for transmission of the transport block. In some examples, a UE may use different sub-channels for transmission of the transport block across multiple slots within its own resource selection window.

[0057] In some implementations, a UE that is initiating a communication with another UE is referred to as a transmitter UE (TX UE), and the UE receiving the communication is referred to as a receiver UE (RX UE). For example, UE 105-1 may be a TX UE and UE 105-2 may be an RX UE. Although FIG. 1 illustrates a single TX UE communicating with a single RX UE, a TX UE may communicate with more than one RX UE via sidelink.

[0058] In some implementations, a TX UE that is initiating sidelink communication may determine the available resources (e.g., sidelink resources) and may select a subset of these resources to communicate with an RX UE based on a resource allocation scheme. Example resource allocation schemes include Mode 1 and Mode 2 resource allocation schemes. In Mode 1 resource allocation scheme (referred to as “Mode 1”), the resources are allocated by a network node for in-coverage UEs. In Mode 2 resource allocation scheme (referred to as “Mode 2”), the TX UE selects the sidelink resources (e.g., sidelink transmission resources).

[0059] In some implementations, the UEs 105 can perform beam maintenance procedures to establish, refine, and / or maintain communications over the sidelink interface 125. To do so, a first UE (e.g., the UE 105-1) can transmit a sidelink CSI-RS over a channel of the sidelink interface 125, such as the PSSCH channel. A second UE (e.g., the UE 105-2) can receive the sidelink CSI-RS and process the signal to measure channel state information. Based on these measurements, the second UE can generate and transmit a beam report indicating, for example,Attorney Docket No. 56990-0012W01 / P64549WO1 a preferred beam (e.g., a CSI resource indicator (CRI)) and / or beam measurements (e.g., layer 1 reference signal received power (Ll-RSRP)), among other information.

[0060] To perform beam reporting during beam maintenance, the PSFCH can be used. However, a means for determining which PSFCH resource to use for beam reporting may not be defined. One option is to map multiple sidelink CSI-RS resources to one set of PSFCH resources. In such a case, CRI and / or Ll-RSRP can be explicitly indicated, such as by using a new PSFCH format (e.g., similar to PUCCH format 2). Another option is to map one sidelink CSI-RS resource to one set of PSFCH resources. In this case, CRI can be implicitly indicated via the resource association, and PSFCH format 0 can be used. Ll-RSRP can also be implicitly indicated by, for example, exploring the frequency and / or code domain PSFCH resource in the set of PSFCH resources. Alternatively, whether or not Ll-RSRP satisfies a certain condition can be implicitly indicated via the presence of a PSFCH transmission. However, these options do not provide the details of the mapping between sidelink CSI-RS resources and PSFCH resources that are needed to enable PSFCH-based beam reporting.

[0061] In accordance with an aspect of the present disclosure, a resource mapping between sidelink CSI-RS resources and PSFCH resources for PSFCH-based beam reporting is defined. For purposes of the present discussion, consider standalone sidelink CSI-RS transmissions in slot #i (time) and sub-channel (or, frequency resource set index) #j (frequency). Mapping from standalone sidelink CSI-RS transmission resources to a number of physical resource blocks (PRBs) for this standalone sidelink CSI-RS can follow a mapping rule. In some examples, such a mapping rule can be similar to a rule for PSSCH to PSFCH resource mapping.

[0062] In some examples, a time domain mapping is defined in which PSFCH-based beam reporting is at least X slots after standalone sidelink CSI-RS transmission slots. In this example, X can be 2 or 3, or another (pre-)configured value. In some examples, X can be separately (pre-)configured from the time gap between PSSCH and PSFCH.

[0063] In some examples, a frequency domain mapping is defined. Such a mapping can include some or all of the following procedures: First, sidelink CSI-RS resource set(s) are indexed (total number is Y). Such an index can follow a slot index first and sub-channel index second rule, or sub-channel index first and slot index second rule, among others. Second, the PSFCH PRBs are indexed for beam reporting (total number is Z). Such an index can follow a PRB index rule in a slot, among other rules. In some examples, a bitmap with length of total number of PRBs in a resource pool is (pre-)configured for beam reporting. In this example, aAttorney Docket No. 56990-0012W01 / P64549WO1‘ 1’ bit can indicate that the corresponding PRB can be used for beam reporting, whereas a ‘0’ bit can indicate that the corresponding PRB is not used for beam reporting (and is instead used, e.g., for HARQ feedback). In this case, the number of ‘ 1’ bits in the bitmap is Z.

[0064] Next, each sidelink CSI-RS resource set in a slot can be associated with (Z / Y) PSFCH PRBs for beam reporting. For example, the first sidelink CSI-RS resource set can be mapped to the first (Z / Y) PSFCH PRBs for beam reporting; the second sidelink CSI-RS resource set can be mapped to the second (Z / Y) PSFCH PRBs, and so on. Then, each sidelink CSI-RS resource in a resource set can be associated with one or more PSFCH PRBs for beam reporting using, for example, contiguous mapping or interlaced mapping. For instance, suppose the number of PSFCH PRBs for beam reporting associated with standalone sidelink CSI-RS transmission is A = (Z / Y), and the number of sidelink CSI-RS transmissions in a slot is B. It is expected that A is an integer multiple of B. If A is not an integer multiple of B, [-] * B PRBs can be used for beam reporting. In some examples, contiguous mapping is used in which the first sidelink CSI-RS is mapped to the first C = [-] PRBs for beam reporting; the second SL BACSI-RS is mapped to the second C = [-] PRBs for beam reporting, and so on. Such a mapping has the benefit of simplicity. In some examples, interlaced mapping can be used in which the first sidelink CSI-RS is mapped to the first PRB, the (B+l)-th PRB, and so on for beam reporting; the second SL CSI-RS is mapped to the second PRB, the (B+2)-th PRB and so on for beam reporting, etc. Interlaced mapping is more complex than contiguous mapping, but has the benefit of being frequency selective and / or frequency diverse.

[0065] From here, and supposing a sidelink CSI-RS resource is mapped to C PSFCH PRBs for beam reporting, the PSFCH resources can be indexed among these C PSFCH PRBs (e.g., in the coding domain). Such an indexing can follow a PRB index first and cyclic shift index second rule, or a cyclic shift index first and PRB index second rule, among others. Suppose the number of PSFCH resources for beam reporting for a sidelink CSI-RS is D = C * (number of cyclic shift pairs). Then, supposing the total number of Ll-RSRP levels is E, the first E PSFCH resources within the total of D PSFCH resources can be used to indicate the Ll-RSRP measurement value of the corresponding sidelink CSI-RS. In this way, Ll-RSRP can be implicitly indicated.

[0066] Referring to FIG. 2, a diagram 200 of an example resource mapping between sidelink CSI-RS resources and PSFCH resources for PSFCH-based beam reporting is shown. In thisAttorney Docket No. 56990-0012W01 / P64549WO1 example, three sidelink CSI-RS are transmitted by a TX UE and received by a RX UE using sidelink CSI-RS resources 202a, 202b, and 202c. Using the techniques described herein, the RX UE transmits (and the TX UE receives) beam reporting for the CSI-RS on PSFCH resources 204a, 204b, and 204c. In particular, sidelink CSI-RS resources 202a-c are mapped to PSFCH resources 204a-c in a slot that is a predetermined or (pre-)configured number of slots after the CSI-RS transmission slots according to the time domain mapping described herein. In addition, sidelink CSI-RS resources 202a-c are mapped to PSFCH resources 204a-c associated with PRBs determined according to the frequency domain mapping described herein.

[0067] In accordance with an aspect of the present disclosure, techniques for selecting a transmit beam and / or a receive beam for PSFCH-based beam reporting are described. In some examples, a transmit beam of PSFCH for beam reporting is selected as the beam corresponding to the serving RX beam of PSSCH / PSCCH data transmission. In some examples, the transmit beam of PSFCH for beam reporting is selected as the serving TX beam used for PSFCH for HARQ-ACK transmission to the peer UE. In some examples, beam sweeping over multiple slots is used for transmission of PSFCH during beam reporting. In some examples, a wide beam is selected as the transmit beam of PSFCH for beam reporting. In some examples, a receive beam of PSFCH for beam reporting is selected as the beam corresponding to the serving Tx beam of PSSCH / PSCCH. In some examples, the receive beam of PSFCH for beam reporting is selected as the serving RX beam used for PSFCH for HARQ-ACK reception from the peer UE. In some examples, a wide beam is selected as the receive beam of PSFCH for beam reporting.

[0068] Unlike legacy (FR1) sidelink operation, sidelink operation on FR2 can support beambased transmissions. Thus, to facilitate sidelink beam management in FR2, modification of the channel busy ratio (CBR) and the channel occupancy ratio (CR) to support beam-based transmissions should be considered.

[0069] In accordance with an aspect of the present disclosure, techniques for determining a Channel Busy Ratio (CBR) and Channel occupancy Ratio (CR) in sidelink beam-based transmissions are defined. In general, in sidelink for FR1, there is no standalone CSI-RS and CSI-RS resources. Accordingly, the CR and CBR measurement is based on PSCCH / PSSCH. In sidelink for FR2, standalone CSI-RS resources and beam reporting resources are introduced. As such, the CR and CBR measurement in FR2 could be based either on PSCCH / PSSCHAttorney Docket No. 56990-0012W01 / P64549WO1 resources (e.g., as in legacy / FR1), or on standalone CSI-RS resources. Thus, there can be two different CR and CBR measurements, and their corresponding measurement windows can be different.

[0070] In some examples, if dedicated resources are used for reference signal, beam reporting, and beam indication resources in a resource pool that is shared with PSCCH / PSSCH, then CR and CBR are separately calculated for PSCCH / PSSCH and reference signal / beam reporting / beam indication. In some examples, the CR and CBR measurement window for reference signal / beam reporting / beam indication could be configured separately from that for PSCCH / PSSCH. This allows the measurement window for reference signal / beam reporting / beam indication to be longer in order to compensate for the fewer measurement occasions.

[0071] In some examples, if dedicated resources are used for reference signal, beam reporting, and beam indication resources in a resource pool that is shared with PSCCH / PSSCH, then joint CR and CBR calculation over a resource pool can be used for reference signal / beam reporting / beam indication and PSCCH / PSSCH transmissions. In some examples, an RSSI measurement on the slot with the reference signal for beam management is used for CBR determination. In some examples, a single SL-RSSI is measured on symbols with both sidelink CSI-RS and PSCCH / PSSCH.

[0072] In some examples, only those slots that use the RX beam corresponding to the desired TX beam for sidelink RSSI measurement are accounted for in the CBR definition. In other words, the CBR definition can be directional (whereas legacy CBR is omni-directional). To account for this feature, the sidelink CBR can be defined as follows: SL Channel Busy Ratio (SL CBR) for a given receive beam measured in slot n is defined as the portion of sub-channels in the resource pool whose SL RSSI measured by the UE using the receive beam exceed a (pre- )configured threshold sensed over a CBR measurement window [n-a, n-1], in which a is equal to 100 or 100-2p slots, according to higher layer parameter sl-TimeWindowSizeCBR. When UE is configured to perform partial sensing by higher layers (including when SL DRX is configured), SL RSSI is measured in slots where the UE performs partial sensing and where the UE performs PSCCH / PSSCH reception within the CBR measurement window. The calculation of SL CBR is limited within the slots for which the SL RSSI is measured. If the number of SL RSSI measurement slots within the CBR measurement window is below a (pre- )configured threshold, a (pre-)configured SL CBR value is used.Attorney Docket No. 56990-0012W01 / P64549WO1

[0073] In some examples, only those slots using the same TX beam corresponding to the desired TX beam are accounted for in the CR definition. To capture this feature, the sidelink CR can be defined as follows: Sidelink Channel Occupancy Ratio (SL CR) for a given transmit beam evaluated at slot n is defined as the total number of sub-channels used for its transmissions with the transmit beam in slots [n-a, n-1] and granted in slots [n, n+b] divided by the total number of configured sub-channels in the transmission pool over [n-a, n+b],

[0074] FIG. 3 illustrates a flowchart of an example method 300, according to some implementations. For clarity of presentation, the description that follows generally describes method 300 in the context of the other figures in this description. For example, method 300 can be performed by the UE 105-1 or 105-2 of FIG. 1. It will be understood that method 300 can be performed, for example, by any suitable system, environment, software, hardware, or a combination of systems, environments, software, and hardware, as appropriate. In some implementations, various steps of method 300 can be run in parallel, in combination, in loops, or in any order.

[0075] Operations of the method 300 include obtaining (e.g., receiving), by a first UE, a sidelink CSI-RS transmitted by a second UE (302). One or more PSFCH resources for beam reporting based on the sidelink CSI-RS are then determined based on a mapping rule (304). A beam report is transmitted to the second UE using the determined one or more PSFCH resources (306).

[0076] In some examples, the mapping rule includes a time domain mapping rule, a frequency domain mapping rule, or both. The time domain mapping rule can specify a number (e.g., a predefined or (pre-)configured number) of slots between the sidelink CSI-RS and the one or more PSFCH resources. The frequency domain rule can cause the UE to perform one or more of the following operations: indexing one or more sidelink CSI-RS resource sets; indexing one or more PSFCH PRBs; associating each of the sidelink CSI-RS resource sets in a slot with a number of the one or more PSFCH PRBs; and for each of the one or more sidelink CSI-RS resource sets, associating each sidelink CSI-RS resource in the respective sidelink CSI-RS resource set with at least one of the one or more PSFCH PRBs; and indexing PSFCH resources among the at least one of the one or more PSFCH PRBs.

[0077] In some examples, the one or more sidelink CSI-RS resource sets are indexed according to a slot index first and sub-channel index second rule, or a sub-channel index first and a slot index second rule. In some examples, the number of the one or more PRBs associated withAttorney Docket No. 56990-0012W01 / P64549WO1 each of the sidelink CSI-RS resource sets in a slot is a number of the one or more PRBs divided by a number of the one or more sidelink CSI-RS resource sets. In some examples, each sidelink CSI-RS resource in the respective sidelink CSI-RS resource set is associated with the at least one of the one or more PSFCH PRBs according to a contiguous mapping scheme or an interlaced mapping scheme. In some examples, the PSFCH resources are indexed among the at least one of the one or more PSFCH PRBs according to a PRB index first and cyclic shift index second rule, or a cyclic shift index first and a PRB index second rule.

[0078] In some examples, operations of the method 300 further include selecting a beam for transmission of the beam report to the second UE; and transmitting the beam report to the second UE using the selected beam. In some examples, the selected beam is a beam corresponding to a receive beam of the second UE, a beam corresponding to a transmit beam used for transmission of a hybrid automatic repeat request acknowledgement (HARQ-ACK) over PSFCH to the second UE, a beam selected as part of a beam sweeping process over multiple slots, or a wide beam.

[0079] FIG. 4 illustrates a flowchart of an example method 400, according to some implementations. For clarity of presentation, the description that follows generally describes method 400 in the context of the other figures in this description. For example, method 400 can be performed by the UE 105-1 or 105-2 of FIG. 1. It will be understood that method 400 can be performed, for example, by any suitable system, environment, software, hardware, or a combination of systems, environments, software, and hardware, as appropriate. In some implementations, various steps of method 400 can be run in parallel, in combination, in loops, or in any order.

[0080] Operations of the method 400 include transmitting, by a first UE, a sidelink CSI-RS to a second UE (402). One or more PSFCH resources for beam reporting based on the sidelink CSI-RS are then determined based on a mapping rule (404). A beam report is received from the second UE using the determined one or more PSFCH resources (406).

[0081] In some examples, the mapping rule includes a time domain mapping rule, a frequency domain mapping rule, or both. The time domain mapping rule can specify a number (e.g., a predefined or (pre-)configured number) of slots between the sidelink CSI-RS and the one or more PSFCH resources. The frequency domain rule can cause the UE to perform one or more of the following operations: indexing one or more sidelink CSI-RS resource sets; indexing one or more PSFCH PRBs; associating each of the sidelink CSI-RS resource sets in a slot with aAttorney Docket No. 56990-0012W01 / P64549WO1 number of the one or more PSFCH PRBs; and for each of the one or more sidelink CSI-RS resource sets, associating each sidelink CSI-RS resource in the respective sidelink CSI-RS resource set with at least one of the one or more PSFCH PRBs; and indexing PSFCH resources among the at least one of the one or more PSFCH PRBs.4

[0082] In some examples, the one or more sidelink CSI-RS resource sets are indexed according to a slot index first and sub-channel index second rule, or a sub-channel index first and a slot index second rule. In some examples, the number of the one or more PRBs associated with each of the sidelink CSI-RS resource sets in a slot is a number of the one or more PRBs divided by a number of the one or more sidelink CSI-RS resource sets. In some examples, each sidelink CSI-RS resource in the respective sidelink CSI-RS resource set is associated with the at least one of the one or more PSFCH PRBs according to a contiguous mapping scheme or an interlaced mapping scheme. In some examples, the PSFCH resources are indexed among the at least one of the one or more PSFCH PRBs according to a PRB index first and cyclic shift index second rule, or a cyclic shift index first and a PRB index second rule.

[0083] In some examples, operations of the method 400 further include selecting a beam for reception of the beam report from the second UE; and receiving the beam report from the second UE using the selected beam. In some examples, the selected beam is a beam corresponding to a transmit beam of the second UE, a beam corresponding to a receive beam used for transmission of a HARQ-ACK over PSFCH from the second UE, or a wide beam.

[0084] FIG. 5 illustrates a flowchart of an example method 500, according to some implementations. For clarity of presentation, the description that follows generally describes method 500 in the context of the other figures in this description. For example, method 500 can be performed by the UE 105-1 or 105-2 of FIG. 1. It will be understood that method 500 can be performed, for example, by any suitable system, environment, software, hardware, or a combination of systems, environments, software, and hardware, as appropriate. In some implementations, various steps of method 500 can be run in parallel, in combination, in loops, or in any order.

[0085] Operations of the method 500 include monitoring, by a first UE, a resource pool associated with a sidelink interface between the first UE and a second UE (502). Based on the monitored resource pool, the first UE determines at least one of a sidelink channel busy ratio (SL CBR) for a particular receive beam of the first UE, or a sidelink channel occupancy ratio (SL CR) for a particular transmit beam of the first UE.Attorney Docket No. 56990-0012W01 / P64549WO1

[0086] In some examples, the resource pool includes at least one reference signal, beam reporting, or beam indication resource that is shared with at least one physical sidelink control channel (PSCCH) or physical sidelink shared channel (PSSCH) resource. In some examples, the at least one of the SL CBR or the SL CR is determined for reference signal, beam reporting, and beam indication, the operations of the method 500 further include determining at least one of a second SL CBR or a second SL CR for PSCCH and PSSCH.

[0087] In some examples, operations of the method 500 include receiving a measurement window configuration, monitoring the resource pool according to the measurement window configuration; and determining the at least one of the SL CBR or the SL CR based on the monitoring of the resource pool according to the measurement window configuration. In some examples, the measurement window configuration is for reference signal, beam reporting, and beam indication, the operations of the method 500 further include receiving a separate measurement window configuration for PSCCH and PSSCH. In some examples, the at least one of the SL CBR or SL CR is determined for reference signal, beam reporting, beam indication, PSCCH, and PSSCH.

[0088] In some examples, the particular receive beam of the first UE corresponds to a transmit beam for a sidelink received signal strength indicator (SL-RSSI). In some examples, the particular transmit beam of the first UE corresponds to a desired transmit beam for the first UE.

[0089] FIG. 6 illustrates an example UE 600, according to some implementations. The UE 600 may be similar to and substantially interchangeable with UEs 105 of FIG. 1.

[0090] The UE 600 may be any mobile or non-mobile computing device, such as, for example, mobile phones, computers, tablets, industrial wireless sensors (for example, microphones, pressure sensors, thermometers, motion sensors, accelerometers, inventory sensors, electric voltage / current meters, etc.), video devices (for example, cameras, video cameras, etc.), wearable devices (for example, a smart watch), relaxed-IoT devices.

[0091] The UE 600 may include processors 602, RF interface circuitry 604, memory / storage 606, user interface 608, sensors 610, driver circuitry 612, power management integrated circuit (PMIC) 614, one or more antenna(s) 616, and battery 618. The components of the UE 600 may be implemented as integrated circuits (ICs), portions thereof, discrete electronic devices, or other modules, logic, hardware, software, firmware, or a combination thereof. The block diagram of FIG. 6 is intended to show a high-level view of some of the components of the UE 600. However, some of the components shown may be omitted, additional components may beAttorney Docket No. 56990-0012W01 / P64549WO1 present, and different arrangement of the components shown may occur in other implementations.

[0092] The components of the UE 600 may be coupled with various other components over one or more interconnects 620, which may represent any type of interface, input / output, bus (local, system, or expansion), transmission line, trace, optical connection, etc. that allows various circuit components (on common or different chips or chipsets) to interact with one another.

[0093] The processors 602 may include processor circuitry such as, for example, baseband processor circuitry (BB) 622A, central processor unit circuitry (CPU) 622B, and graphics processor unit circuitry (GPU) 622C. The processors 602 may include any type of circuitry or processor circuitry that executes or otherwise operates computer-executable instructions, such as program code, software modules, or functional processes from memory / storage 606 to cause the UE 600 to perform operations as described herein.

[0094] In some implementations, the baseband processor circuitry 622A may access a communication protocol stack 624 in the memory / storage 606 to communicate over a 3 GPP compatible network. In general, the baseband processor circuitry 622A may access the communication protocol stack to: perform user plane functions at a physical (PHY) layer, medium access control (MAC) layer, radio link control (RLC) layer, packet data convergence protocol (PDCP) layer, service data adaptation protocol (SDAP) layer, and PDU layer; and perform control plane functions at a PHY layer, MAC layer, RLC layer, PDCP layer, RRC layer, and a non-access stratum layer. In some implementations, the PHY layer operations may additionally / altematively be performed by the components of the RF interface circuitry 604. The baseband processor circuitry 622A may generate or process baseband signals or waveforms that carry information in 3 GPP-compatible networks. In some implementations, the waveforms for NR may be based cyclic prefix orthogonal frequency division multiplexing (OFDM) “CP-OFDM” in the uplink or downlink, and discrete Fourier transform spread OFDM “DFT-S-OFDM” in the uplink.

[0095] The memory / storage 606 may include one or more non -transitory, computer-readable media that includes instructions (for example, communication protocol stack 624) that may be executed by one or more of the processors 602 to cause the UE 600 to perform various operations described herein. The memory / storage 606 include any type of volatile or nonvolatile memory that may be distributed throughout the UE 600. In some implementations,Attorney Docket No. 56990-0012W01 / P64549WO1 some of the memory / storage 606 may be located on the processors 602 themselves (for example, LI and L2 cache), while other memory / storage 606 is external to the processors 602 but accessible thereto via a memory interface. The memory / storage 606 may include any suitable volatile or non-volatile memory such as, but not limited to, dynamic random access memory (DRAM), static random access memory (SRAM), erasable programmable read only memory (EPROM), electrically erasable programmable read only memory (EEPROM), Flash memory, solid-state memory, or any other type of memory device technology.

[0096] The RF interface circuitry 604 may include transceiver circuitry and radio frequency front module (RFEM) that allows the UE 600 to communicate with other devices over a radio access network. The RF interface circuitry 604 may include various elements arranged in transmit or receive paths. These elements may include, for example, switches, mixers, amplifiers, filters, synthesizer circuitry, control circuitry, etc.

[0097] In the receive path, the RFEM may receive a radiated signal from an air interface via antenna(s) 616 and proceed to filter and amplify (with a low-noise amplifier) the signal. The signal may be provided to a receiver of the transceiver that downconverts the RF signal into a baseband signal that is provided to the baseband processor of the processors 602.

[0098] In the transmit path, the transmitter of the transceiver up-converts the baseband signal received from the baseband processor and provides the RF signal to the RFEM. The RFEM may amplify the RF signal through a power amplifier prior to the signal being radiated across the air interface via the antenna(s) 616. In various implementations, the RF interface circuitry 604 may be configured to transmit / receive signals in a manner compatible with NR access technologies.

[0099] The antenna(s) 616 may include one or more antenna elements to convert electrical signals into radio waves to travel through the air and to convert received radio waves into electrical signals. The antenna elements may be arranged into one or more antenna panels. The antenna(s) 616 may have antenna panels that are omnidirectional, directional, or a combination thereof to enable beamforming and multiple input, multiple output communications. The antenna(s) 616 may include microstrip antennas, printed antennas fabricated on the surface of one or more printed circuit boards, patch antennas, phased array antennas, etc. The antenna(s) 616 may have one or more panels designed for specific frequency bands including bands in FR1 or FR2.Attorney Docket No. 56990-0012W01 / P64549WO1

[0100] The user interface 608 includes various input / output (I / O) devices designed to enable user interaction with the UE 600. The user interface 608 includes input device circuitry and output device circuitry. Input device circuitry includes any physical or virtual means for accepting an input including, inter alia, one or more physical or virtual buttons (for example, a reset button), a physical keyboard, keypad, mouse, touchpad, touchscreen, microphones, scanner, headset, or the like. The output device circuitry includes any physical or virtual means for showing information or otherwise conveying information, such as sensor readings, actuator position(s), or other like information. Output device circuitry may include any number or combinations of audio or visual display, including, inter alia, one or more simple visual outputs / indicators (for example, binary status indicators such as light emitting diodes “LEDs” and multi -character visual outputs), or more complex outputs such as display devices or touchscreens (for example, liquid crystal displays “LCDs,” LED displays, quantum dot displays, projectors, etc.), with the output of characters, graphics, multimedia objects, and the like being generated or produced from the operation of the UE 600.

[0101] The sensors 610 may include devices, modules, or subsystems whose purpose is to detect events or changes in its environment and send the information (sensor data) about the detected events to some other device, module, subsystem, etc. Examples of such sensors include, inter alia, inertia measurement units including accelerometers, gyroscopes, or magnetometers; microelectromechanical systems or nanoelectromechanical systems including 3-axis accelerometers, 3-axis gyroscopes, or magnetometers; level sensors; temperature sensors (for example, thermistors); pressure sensors; image capture devices (for example, cameras or lensless apertures); light detection and ranging sensors; proximity sensors (for example, infrared radiation detector and the like); depth sensors; ambient light sensors; ultrasonic transceivers; microphones or other like audio capture devices; etc.

[0102] The driver circuitry 612 may include software and hardware elements that operate to control particular devices that are embedded in the UE 600, attached to the UE 600, or otherwise communicatively coupled with the UE 600. The driver circuitry 612 may include individual drivers allowing other components to interact with or control various input / output (I / O) devices that may be present within, or connected to, the UE 600. For example, driver circuitry 612 may include a display driver to control and allow access to a display device, a touchscreen driver to control and allow access to a touchscreen interface, sensor drivers to obtain sensor readings of sensors 610 and control and allow access to sensors 610, drivers to obtain actuator positions of electro-mechanic components or control and allow access to theAttorney Docket No. 56990-0012W01 / P64549WO1 electro-mechanic components, a camera driver to control and allow access to an embedded image capture device, audio drivers to control and allow access to one or more audio devices.

[0103] The PMIC 614 may manage power provided to various components of the UE 600. In particular, with respect to the processors 602, the PMIC 614 may control power-source selection, voltage scaling, battery charging, or DC-to-DC conversion.

[0104] In some implementations, the PMIC 614 may control, or otherwise be part of, various power saving mechanisms of the UE 600. A battery 618 may power the UE 600, although in some examples the UE 600 may be mounted deployed in a fixed location, and may have a power supply coupled to an electrical grid. The battery 618 may be a lithium ion battery, a metal-air battery, such as a zinc-air battery, an aluminum-air battery, a lithium-air battery, and the like. In some implementations, such as in vehicle-based applications, the battery 618 may be a typical lead-acid automotive battery.

[0105] As used herein, the terms “access node,” “access point,” or the like may describe equipment that provides the radio baseband functions for data and / or voice connectivity between a network and one or more users. These access nodes can be referred to as BS, gNBs, RAN nodes, eNBs, NodeBs, RSUs, TRxPs or TRPs, and so forth, and can include ground stations (e.g., terrestrial access points) or satellite stations providing coverage within a geographic area (e.g., a cell). As used herein, the term “NG RAN node” or the like may refer to an access node that operates in an NR or 5G system (for example, a gNB), and the term “E- UTRAN node” or the like may refer to an access node that operates in an LTE or 4G system (e.g., an eNB). According to various implementations, the access node may be implemented as one or more of a dedicated physical device such as a macrocell base station, and / or a low power (LP) base station for providing femtocells, picocells or other like cells having smaller coverage areas, smaller user capacity, or higher bandwidth compared to macrocells.

[0106] In some implementations, all or parts of the access node may be implemented as one or more software entities running on server computers as part of a virtual network, which may be referred to as a CRAN and / or a virtual baseband unit pool (vBBUP). In V2X scenarios, the access node may be or act as a “Road Side Unit.” The term “Road Side Unit” or “RSU” may refer to any transportation infrastructure entity used for V2X communications. An RSU may be implemented in or by a suitable RAN node or a stationary (or relatively stationary) UE, where an RSU implemented in or by a UE may be referred to as a “UE-type RSU,” an RSUAttorney Docket No. 56990-0012W01 / P64549WO1 implemented in or by an eNB may be referred to as an “eNB-type RSU,” an RSU implemented in or by a gNB may be referred to as a “gNB-type RSU,” and the like.

[0107] Various components may be described as performing a task or tasks, for convenience in the description. Such descriptions should be interpreted as including the phrase “configured to.” Reciting a component that is configured to perform one or more tasks is expressly intended not to invoke 35 U.S.C. § 112(f) interpretation for that component.

[0108] For one or more embodiments, at least one of the components set forth in one or more of the preceding figures may be configured to perform one or more operations, techniques, processes, or methods as set forth in the example section below. For example, the baseband circuitry as described above in connection with one or more of the preceding figures may be configured to operate in accordance with one or more of the examples set forth below. For another example, circuitry associated with a UE, base station, network element, etc. as described above in connection with one or more of the preceding figures may be configured to operate in accordance with one or more of the examples set forth below in the example section.

[0109] Any of the above-described examples may be combined with any other example (or combination of examples), unless explicitly stated otherwise. The foregoing description of one or more implementations provides illustration and description, but is not intended to be exhaustive or to limit the scope of embodiments to the precise form disclosed. Modifications and variations are possible in light of the above teachings or may be acquired from practice of various embodiments.

[0110] Although the embodiments above have been described in considerable detail, numerous variations and modifications will become apparent to those skilled in the art once the above disclosure is fully appreciated. It is intended that the following claims be interpreted to embrace all such variations and modifications.[OHl] It is well understood that the use of personally identifiable information should follow privacy policies and practices that are generally recognized as meeting or exceeding industry or governmental requirements for maintaining the privacy of users. In particular, personally identifiable information data should be managed and handled so as to minimize risks of unintentional or unauthorized access or use, and the nature of authorized use should be clearly indicated to users.

Claims

Attorney Docket No. 56990-0012W01 / P64549WO1CLAIMSWe Claim:

1. One or more processors configured to, when executing instructions stored in a memory, perform operations comprising: obtaining a sidelink channel state information reference signal (CSI-RS) transmitted by a user equipment (UE); determining, based on a mapping rule, one or more physical sidelink feedback channel (PSFCH) resources for beam reporting, wherein the mapping rule specifies a mapping between one or more resources for the sidelink CSI-RS and the one or more PSFCH resources; and causing transmission of a beam report to the UE using the determined one or more PSFCH resources.

2. The one or more processors of claim 1, wherein the mapping rule comprises at least one of a time domain mapping rule or a frequency domain mapping rule.

3. The one or more processors of claim 1 or 2, wherein the mapping rule specifies a number of slots between the sidelink CSI-RS and the one or more PSFCH resources.

4. The one or more processors of any preceding claim, wherein determining, based on the mapping rule, the one or more PSFCH resources for beam reporting comprises: indexing one or more sidelink CSI-RS resource sets; indexing one or more PSFCH physical resource blocks (PRBs); associating each of the sidelink CSI-RS resource sets in a slot with a number of the one or more PSFCH PRBs; and for each of the one or more sidelink CSI-RS resource sets, associating each sidelink CSI-RS resource in the respective sidelink CSI-RS resource set with at least one of the one or more PSFCH PRBs; and indexing PSFCH resources among the at least one of the one or more PSFCH PRBs.

5. The one or more processors of claim 4, wherein the one or more sidelink CSI-RS resource sets are indexed according to a slot index first and sub-channel index second rule, or a subchannel index first and a slot index second rule.Attorney Docket No. 56990-0012W01 / P64549WO16. The one or more processors of claim 4, wherein the number of the one or more PRBs associated with each of the sidelink CSI-RS resource sets in a slot comprises a number of the one or more PRBs divided by a number of the one or more sidelink CSI-RS resource sets.

7. The one or more processors of claim 4, wherein each sidelink CSI-RS resource in the respective sidelink CSI-RS resource set is associated with the at least one of the one or more PSFCH PRBs according to a contiguous mapping scheme or an interlaced mapping scheme.

8. The one or more processors of claim 4, wherein the PSFCH resources are indexed among the at least one of the one or more PSFCH PRBs according to a PRB index first and cyclic shift index second rule, or a cyclic shift index first and a PRB index second rule.

9. The one or more processors of any preceding claim, further comprising: selecting a beam for transmission of the beam report to the UE; and transmitting the beam report to the UE using the selected beam.

10. The one or more processors of claim 9, wherein the selected beam comprises: a beam corresponding to a receive beam of the UE, a beam corresponding to a transmit beam used for transmission of a hybrid automatic repeat request acknowledgement (HARQ-ACK) over PSFCH to the UE, a beam selected as part of a beam sweeping process over multiple slots, or a wide beam.

11. The one or more processors of any preceding claim, wherein the beam report comprises at least one of a CSI resource indicator (CRI) or a layer 1 reference signal received power (Ll- RSRP).

12. A method, comprising: obtaining a sidelink channel state information reference signal (CSI-RS) transmitted by a user equipment (UE); determining, based on a mapping rule, one or more physical sidelink feedback channel (PSFCH) resources for beam reporting, wherein the mapping rule specifies a mapping between one or more resources for the sidelink CSI-RS and the one or more PSFCH resources; and causing transmission of a beam report to the UE using the determined one or more PSFCH resources.Attorney Docket No. 56990-0012W01 / P64549WO113. A user equipment (UE), comprising: radio frequency (RF) circuitry; one or more processors; and memory storing instructions executable by the one or more processors to perform operations comprising: transmitting, using the RF circuitry, a sidelink channel state information reference signal (CSI-RS) to a user equipment (UE); determining, based on a mapping rule, one or more physical sidelink feedback channel (PSFCH) resources for beam reporting, wherein the mapping rule specifies a mapping between one or more resources for the sidelink CSI-RS and the one or more PSFCH resources; and receiving a beam report from the UE using the determined one or more PSFCH resources.

14. The UE of claim 13, wherein the mapping rule comprises at least one of a time domain mapping rule or a frequency domain mapping rule.

15. The UE of claim 13 or 14, wherein the mapping rule specifies a number of slots between the sidelink CSI-RS and the one or more PSFCH resources.

16. The UE of any of claims 13 to 15, wherein determining, based on the mapping rule, the one or more PSFCH resources for beam reporting comprises: indexing one or more sidelink CSI-RS resource sets; indexing one or more PSFCH physical resource blocks (PRBs); associating each of the sidelink CSI-RS resource sets in a slot with a number of the one or more PSFCH PRBs; and for each of the one or more sidelink CSI-RS resource sets, associating each sidelink CSI-RS resource in the respective sidelink CSI-RS resource set with at least one of the one or more PSFCH PRBs; and indexing PSFCH resources among the at least one of the one or more PSFCH PRBs.

17. The UE of claim 16, wherein the one or more sidelink CSI-RS resource sets are indexed according to a slot index first and sub-channel index second rule, or a sub-channel index first and a slot index second rule.Attorney Docket No. 56990-0012W01 / P64549WO118. The UE of claim 16, wherein the number of the one or more PRBs associated with each of the sidelink CSI-RS resource sets in a slot comprises a number of the one or more PRBs divided by a number of the one or more sidelink CSI-RS resource sets.

19. The UE of claim 16, wherein each sidelink CSI-RS resource in the respective sidelink CSI-RS resource set is associated with the at least one of the one or more PSFCH PRBs according to a contiguous mapping scheme or an interlaced mapping scheme.

20. The UE of claim 16, wherein the PSFCH resources are indexed among the at least one of the one or more PSFCH PRBs according to a PRB index first and cyclic shift index second rule, or a cyclic shift index first and a PRB index second rule.

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