WO2025065473A1

WO2025065473A1 - Physical sidelink feedback channel transmissions for non-contiguous resource block sets in unlicensed sidelink communications

Info

Publication number: WO2025065473A1
Application number: PCT/CN2023/122457
Authority: WO
Inventors: Siyi Chen; Chih-Hao Liu; Jing Sun; Xiaoxia Zhang; Changlong Xu; Shaozhen GUO; Luanxia YANG; Hao Xu
Original assignee: Qualcomm Inc
Current assignee: Qualcomm Inc
Priority date: 2023-09-28
Filing date: 2023-09-28
Publication date: 2025-04-03
Anticipated expiration: 2026-03-28

Abstract

Various aspects of the present disclosure generally relate to wireless communication. Some aspects of the techniques described herein may facilitate physical sidelink feedback channel (PSFCH) transmissions for non-contiguous resource block (RB) sets. In some aspects, a user equipment (UE) may perform a PSFCH selection process to select PSFCH communications and, if the remaining PSFCH communications are still located at non-contiguous RB sets, the UE may continue to drop PSFCH communications based on one or more rules. In some aspects, the UE may first perform PSFCH dropping operations to form a contiguous PSFCH transmission among RB sets. If the PSFCH communication (s) in the resulting contiguous RB sets exceed the UE capability, then the UE may perform PSFCH dropping to select the PSFCH communications for transmission. In some aspects, the UE may use a common interlace to form a contiguous PSFCH transmission among RB sets.

Description

PHYSICAL SIDELINK FEEDBACK CHANNEL TRANSMISSIONS FOR NON-CONTIGUOUS RESOURCE BLOCK SETS IN UNLICENSED SIDELINK COMMUNICATIONS

FIELD OF THE DISCLOSURE

Aspects of the present disclosure generally relate to wireless communication and specifically, to techniques and apparatuses for physical sidelink feedback channel transmissions for non-contiguous resource block sets in unlicensed sidelink communications.

BACKGROUND

Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasts. Typical wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources (for example, bandwidth or transmit power) . Examples of such multiple-access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single-carrier frequency division multiple access (SC-FDMA) systems, time division synchronous code division multiple access (TD-SCDMA) systems, and Long Term Evolution (LTE) . LTE/LTE-Advanced is a set of enhancements to the Universal Mobile Telecommunications System (UMTS) mobile standard promulgated by the Third Generation Partnership Project (3GPP) .

The above multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different UEs to communicate on a municipal, national, regional, or global level. New Radio (NR) , which may be referred to as 5G, is a set of enhancements to the LTE mobile standard promulgated by the 3GPP. NR is designed to better support mobile broadband internet access by improving spectral efficiency, lowering costs, improving services, making use of new spectrum, and better integrating with other open standards using orthogonal frequency division multiplexing (OFDM) with a cyclic prefix (CP) (CP-OFDM) on the downlink, using CP-OFDM or single-carrier frequency division multiplexing (SC-FDM) (also known as discrete Fourier transform spread OFDM (DFT-s-OFDM) ) on the uplink, as well as supporting beamforming, multiple-input multiple-output (MIMO) antenna technology, and carrier aggregation. As the demand for mobile broadband access continues to increase, further improvements in LTE, NR, and other radio access technologies remain useful.

In unlicensed sidelink communications, a user equipment (UE) can communicate with one or more other UEs over a sidelink channel. To facilitate reliability in communication, a feedback channel can be used by the UE to transmit feedback to indicate whether the UE successfully received and decoded communications from the one or more other UEs. Some UEs support transmission of simultaneous feedback signals across contiguous resource block sets, while other UEs support transmission of simultaneous feedback signals across non-contiguous resource block sets.

SUMMARY

Some aspects described herein relate to an apparatus for wireless communication at a user equipment (UE) . The apparatus may include one or more memories storing processor-executable code and one or more processors coupled with the one or more memories. At least one processor of the one or more processors may be configured to cause the UE to monitor at least one sidelink channel associated with an unlicensed spectrum for a plurality of sidelink communications. At least one processor of the one or more processors may be configured to cause the UE to transmit a subset of physical sidelink feedback channel (PSFCH) communications, of a set of PSFCH communications, using a second plurality of resource block (RB) sets that are contiguous in a frequency domain, wherein the second plurality of RB sets is selected from among a first plurality of RB sets corresponding to the set of PSFCH communications, and wherein the first plurality of RB sets is selected using a PSFCH selection process.

Some aspects described herein relate to an apparatus for wireless communication at a UE. The apparatus may include one or more memories storing processor-executable code and one or more processors coupled with the one or more memories. At least one processor of the one or more processors may be configured to cause the UE to monitor at least one sidelink channel associated with an unlicensed spectrum for a plurality of sidelink communications. At least one processor of the one or more processors may be configured to cause the UE to transmit a subset of PSFCH communications, of a set of PSFCH communications, using a second plurality of RB sets selected, using a group-based selection operation, from among a first plurality of RB sets corresponding to the set of PSFCH communications associated with the plurality of sidelink communications.

Some aspects described herein relate to an apparatus for wireless communication at a UE. The apparatus may include one or more memories storing processor-executable code and one or more processors coupled with the one or more memories. At least one processor of the one or more processors may be configured to cause the UE to monitor at least one sidelink channel associated with an unlicensed spectrum for a plurality of sidelink communications. At least one processor of the one or more processors may be configured to cause the UE to transmit, in a non-contiguous plurality of RB sets, a set of PSFCH communications associated with the plurality of sidelink communications, wherein at least one RB set of the plurality of RB sets omits a PSFCH communication, and wherein transmitting the set of PSFCH communications comprises transmitting a common interlace in the at least one RB set, wherein the common interlace is associated with the set of PSFCH communications.

Some aspects described herein relate to a method of wireless communication performed by a UE. The method may include monitoring at least one sidelink channel associated with an unlicensed spectrum for a plurality of sidelink communications. The method may include transmitting a subset of PSFCH communications, of a set of PSFCH communications, using a second plurality of RB sets that are contiguous in a frequency domain, wherein the second plurality of RB sets is selected from among a first plurality of RB sets corresponding to the set of PSFCH communications, and wherein the first plurality of RB sets is selected using a PSFCH selection process.

Some aspects described herein relate to a method of wireless communication performed by a UE. The method may include monitoring at least one sidelink channel associated with an unlicensed spectrum for a plurality of sidelink communications. The method may include transmitting a subset of PSFCH communications, of a set of PSFCH communications, using a second plurality of RB sets selected, using a group-based selection operation, from among a first plurality of RB sets corresponding to the set of PSFCH communications associated with the plurality of sidelink communications.

Some aspects described herein relate to a method of wireless communication performed by a UE. The method may include monitoring at least one sidelink channel associated with an unlicensed spectrum for a plurality of sidelink communications. The method may include transmitting, in a non-contiguous plurality of RB sets, a set of PSFCH communications associated with the plurality of sidelink communications, wherein at least one RB set of the plurality of RB sets omits a PSFCH communication, and wherein transmitting the set of PSFCH communications comprises transmitting a common interlace in the at least one RB set, wherein the common interlace is associated with the set of PSFCH communications.

Some aspects described herein relate to a non-transitory computer-readable medium that stores a set of instructions for wireless communication by a UE. The set of instructions, when executed by one or more processors of the UE, may cause the UE to monitor at least one sidelink channel associated with an unlicensed spectrum for a plurality of sidelink communications. The set of instructions, when executed by one or more processors of the UE, may cause the UE to transmit a subset of PSFCH communications, of a set of PSFCH communications, using a second plurality of RB sets that are contiguous in a frequency domain, wherein the second plurality of RB sets is selected from among a first plurality of RB sets corresponding to the set of PSFCH communications, and wherein the first plurality of RB sets is selected using a PSFCH selection process.

Some aspects described herein relate to a non-transitory computer-readable medium that stores a set of instructions for wireless communication by a UE. The set of instructions, when executed by one or more processors of the UE, may cause the UE to monitor at least one sidelink channel associated with an unlicensed spectrum for a plurality of sidelink communications. The set of instructions, when executed by one or more processors of the UE, may cause the UE to transmit a subset of PSFCH communications, of a set of PSFCH communications, using a second plurality of RB sets selected, using a group-based selection operation, from among a first plurality of RB sets corresponding to the set of PSFCH communications associated with the plurality of sidelink communications.

Some aspects described herein relate to a non-transitory computer-readable medium that stores a set of instructions for wireless communication by a UE. The set of instructions, when executed by one or more processors of the UE, may cause the UE to monitor at least one sidelink channel associated with an unlicensed spectrum for a plurality of sidelink communications. The set of instructions, when executed by one or more processors of the UE, may cause the UE to transmit, in a non-contiguous plurality of RB sets, a set of PSFCH communications associated with the plurality of sidelink communications, wherein at least one RB set of the plurality of RB sets omits a PSFCH communication, and wherein transmitting the set of PSFCH communications comprises transmitting a common interlace in the at least one RB set, wherein the common interlace is associated with the set of PSFCH communications.

Some aspects described herein relate to an apparatus for wireless communication. The apparatus may include means for monitoring at least one sidelink channel associated with an unlicensed spectrum for a plurality of sidelink communications. The apparatus may include means for transmitting a subset of PSFCH communications, of a set of PSFCH communications, using a second plurality of RB sets that are contiguous in a frequency domain, wherein the second plurality of RB sets is selected from among a first plurality of RB sets corresponding to the set of PSFCH communications, and wherein the first plurality of RB sets is selected using a PSFCH selection process.

Some aspects described herein relate to an apparatus for wireless communication. The apparatus may include means for monitoring at least one sidelink channel associated with an unlicensed spectrum for a plurality of sidelink communications. The apparatus may include means for transmitting a subset of PSFCH communications, of a set of PSFCH communications, using a second plurality of RB sets selected, using a group-based selection operation, from among a first plurality of RB sets corresponding to the set of PSFCH communications associated with the plurality of sidelink communications.

Some aspects described herein relate to an apparatus for wireless communication. The apparatus may include means for monitoring at least one sidelink channel associated with an unlicensed spectrum for a plurality of sidelink communications. The apparatus may include means for transmitting, in a non-contiguous plurality of RB sets, a set of PSFCH communications associated with the plurality of sidelink communications, wherein at least one RB set of the plurality of RB sets omits a PSFCH communication, and wherein transmitting the set of PSFCH communications comprises transmitting a common interlace in the at least one RB set, wherein the common interlace is associated with the set of PSFCH communications.

Aspects generally include a method, apparatus, system, computer program product, non-transitory computer-readable medium, user equipment, base station, network node, network entity, wireless communication device, or processing system as substantially described with reference to and as illustrated by the drawings and specification.

The foregoing has outlined rather broadly the features and technical advantages of examples in accordance with the disclosure in order that the detailed description that follows may be better understood. Additional features and advantages will be described hereinafter. The conception and specific examples disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present disclosure. Such equivalent constructions do not depart from the scope of the appended claims. Characteristics of the concepts disclosed herein, both their organization and method of operation, together with associated advantages will be better understood from the following description when considered in connection with the accompanying figures. Each of the figures is provided for the purposes of illustration and description, and not as a definition of the limits of the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the above-recited features of the present disclosure can be understood in detail, a more particular description, briefly summarized above, may be had by reference to aspects, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only some typical aspects of this disclosure and are therefore not to be considered limiting of its scope, for the description may admit to other equally effective aspects. The same reference numbers in different drawings may identify the same or similar elements.

Figure 1 is a diagram illustrating an example of a wireless network.

Figure 2 is a diagram illustrating an example user equipment (UE) in communication with UEs in a wireless network.

Figure 3 is a diagram illustrating an example of sidelink communications.

Figure 4 is a diagram illustrating an example of a physical sidelink feedback channel (PSFCH) waveform.

Figure 5 is a diagram illustrating an example of simultaneous PSFCH transmission.

Figures 6A-6C are diagrams illustrating examples associated with PSFCH transmissions for non-contiguous resource block sets in unlicensed sidelink communications.

Figures 7A-7C are diagrams illustrating examples associated with PSFCH transmissions for non-contiguous resource block sets in unlicensed sidelink communications.

Figure 8 is a flowchart illustrating an example process performed, for example, at a UE or an apparatus of a UE that supports simultaneous PSFCH communication transmission.

Figure 9 is a flowchart illustrating an example process performed, for example, at a UE or an apparatus of a UE that supports simultaneous PSFCH transmission.

Figure 10 is a flowchart illustrating an example process performed, for example, at a UE or an apparatus of a UE that supports simultaneous PSFCH communication transmission.

Figure 11 is a diagram of an example apparatus for wireless communication that supports simultaneous PSFCH communication transmission.

DETAILED DESCRIPTION

Various aspects of the disclosure are described more fully hereinafter with reference to the accompanying drawings. This disclosure may, however, be embodied in many different forms and are not to be construed as limited to any specific structure or function presented throughout this disclosure. Rather, these aspects are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. One skilled in the art may appreciate that the scope of the disclosure is intended to cover any aspect of the disclosure disclosed herein, whether implemented independently of or combined with any other aspect of the disclosure. For example, an apparatus may be implemented or a method may be practiced using any quantity of the aspects set forth herein. In addition, the scope of the disclosure is intended to cover such an apparatus or method which is practiced using other structure, functionality, or structure and functionality in addition to or other than the various aspects of the disclosure set forth herein. Any aspect of the disclosure disclosed herein may be embodied by one or more elements of a claim.

Several aspects of telecommunication systems will now be presented with reference to various apparatuses and techniques. These apparatuses and techniques will be described in the following detailed description and illustrated in the accompanying drawings by various blocks, modules, components, circuits, steps, processes, or algorithms (collectively referred to as “elements” ) . These elements may be implemented using hardware, software, or a combination of hardware and software. Whether such elements are implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system.

Hybrid automatic repeat request (HARQ) feedback may be transmitted by a user equipment (UE) to indicate whether the UE has received a communication from another device. The HARQ feedback may include an acknowledgement (ACK) to indicate that the UE successfully received the communication from the other device, or may include a negative acknowledgement (NACK) to indicate that the UE did not successfully receive the communication from the other device. In sidelink communications, the other device may be another UE, and the HARQ feedback may be transmitted by the UE to the other UE via a physical sidelink feedback channel (PSFCH) .

An interlace is a basic unit of resource allocation, such as an air interface resource allocation, that is characterized in accordance with any combination of a frequency span (for example, that may be partitioned into sub-bands and/or sub-carriers) , a time span (for example, that may be partitioned into sub-time spans, such as time slots and/or symbols) , and/or one or more physical resource blocks (PRBs) . An interlace may be, for example, a common interlace or a dedicated interlace. In some examples, resources of the common interlace may be accessible to any UE and/or may be shared by a plurality of UEs, while resources of the dedicated interlace may be accessible only to a single UE at a given time. In some examples, each PSFCH transmission may occupy a single common interlace and a quantity (for example, K3) of dedicated PRBs. The quantity of dedicated PRBs may be, for example, one PRB, two PRBs, or five PRBs. In some other examples, each PSFCH transmission may occupy a single dedicated interlace.

A listen-before-talk (LBT) process may be used to regulate access to a channel. For example, a UE may use the LBT process to minimize collisions and interference between the UE and one or more other UEs communicating on a sidelink channel. In one example, the UE may listen to the sidelink channel to identify whether the sidelink channel is being used for transmissions by one or more other UEs. If the UE identifies that the channel is clear (for example, is not being used for transmissions by another UE) , the UE may perform a transmission on the channel. Alternatively, if the UE identifies that the channel is busy (for example, is being used for a transmission by another UE) , the UE may wait a time period and may perform another LBT process to identify whether the channel is clear or busy.

In a first example, a UE that receives a physical sidelink control channel (PSCCH) communication or physical sidelink shared channel (PSSCH) communication may perform a PSFCH transmission on a candidate PSFCH transmission occasion in accordance with the UE failing to transmit on a previous PSFCH transmission occasion due to LBT failure. For example, the UE that receives the PSCCH/PSSCH communication may only perform the PSFCH transmission on the candidate PSFCH transmission occasion if the UE fails to transmit on the previous PSFCH transmission occasion due to LBT failure. In a second example, the UE that receives the PSCCH/PSSCH communication may perform PSFCH transmissions on all PSFCH transmission occasions within a channel occupancy time (COT) . A COT may indicate a time period during which communications between a first UE and a second UE are to occur. The first UE, which may be referred to as a COT initiating UE, may establish the COT in accordance with a time period to be used for communicating with the second UE, which may be referred to as a responding UE. In one example, the first UE may identify the time period in accordance with a quantity of data that is to be transmitted to the second UE, and may establish the COT in accordance with the identified time period. The COT may be used, for example, to reserve one or more resources to be used for the communications between the first UE and the second UE during the time period, and/or may be used to measure one or more characteristics of the channel associated with the COT, such as a channel throughput or a channel performance, among other examples.

In some examples, a UE can support PSFCH transmission over contiguous and non-contiguous resource block (RB) sets. A UE can indicate a UE capability for supporting PSFCH transmissions over contiguous RB sets and/or a UE capability for supporting PSFCH transmissions over non-contiguous RS sets. In some examples, each PSFCH transmission can occupy one common interlace and K3 dedicated PRBs. Cyclic shift on each PRB of the K3 dedicated PRB (s) can be the same. In some examples, the cyclic shift on each PRB of a common interlace can be determined according to a UE implementation.

In some examples, PSFCH communications can be transmitted over non-contiguous RB sets. For example, PSFCH communications associated with different links in different RB sets can be transmitted simultaneously. The support of PSFCH transmission over non-contiguous RB sets is subject to UE capability. Additionally, due to a UE’s capability, there can be a limit on the maximum number of PSFCH communications that can be simultaneously transmitted by the UE. In some examples, when the number of simultaneous PSFCH communications exceed the UE capability, the UE can select the PSFCH communications to be transmitted by performing a PSFCH selection process (which may, in some examples, be referred to as simultaneous PSFCH transmission) . The UE may perform the PSFCH selection process by selecting PSFCH communications based on information carried by the respective PSFCH communication, HARQ-ACK first, conflict indication second, and/or an ascending order of a priority value for information carried by respective PSFCH communications. For example, the PSFCH selection process may be performed by dropping unselected PSFCH communications.

Since the simultaneously transmitted PSFCH communications are associated with different links, the PSFCH communications may be associated with non-contiguous RB sets. When the number of simultaneous PSFCH communications exceeds the UE capability, the UE can select the PSFCH communications, as described above. The outcome of PSFCH selection may be still non-contiguous and thus, a UE that does not support PSFCH transmission over non-contiguous RB sets may be unable to transmit one or more of the PSFCH communications.

Some aspects of the techniques described herein may facilitate PSFCH transmissions for non-contiguous RB sets. In some aspects, for example, a UE may perform the PSFCH selection process described above to select PSFCH communications (for example, buy dropping one or more PSFCH communications) . If the remaining PSFCH communications are still located at non-contiguous RB sets, the UE may continue to drop PSFCH communications based on one or more rules until the remaining PSFCH communications are associated with contiguous RB sets. In some aspects, for example, the UE may perform an additional PSFCH selection process. For example, the UE may continue to drop PSFCH communications until a contiguous PSFCH transmission among RB sets is formed.

In some aspects, the UE may select PSFCH communications (for example, by dropping PSFCH communications) based on a weighted priority value of PSFCH communications in respective RB sets. In some examples, this operation may be repeated until contiguous RB sets are achieved for the simultaneous transmission of the PSFCH communications. For example, in some aspects, the weighted priority value of a PSFCH communication may be an average priority value, a highest priority value, and/or a lowest priority value. In some aspects, the weighted priority value may be based on a quantity of PSFCH communications within each RB set (for example, so that RB sets having more PSFCH communications are prioritized) . In some aspects, the UE may group the RB sets with PSFCH communications into groups containing contiguous RB sets, calculate a weighted priority value of each group and select the group with the lowest weighted priority value for transmission. In some aspects, the weighted priority value of a group may be based on a quantity of PSFCH communications in the group (for example, so that groups of RB sets having more PSFCH communications are prioritized) .

In some aspects, the UE may first perform PSFCH dropping operations to form a contiguous PSFCH transmission among RB sets. If the PSFCH communication (s) in the resulting contiguous RB sets exceed the UE capability, then the UE may performs PSFCH dropping to select the PSFCH communications for transmission. For example, in some aspects, the UE may group the RB sets with PSFCH communications into groups containing contiguous RB sets, calculate a weighted priority value of each group and select the group with the lowest weighted priority value for transmission. In some aspects, the UE may determine a COT status for each RB set (for example, whether each RB set is within the COT or outside of the COT) and may group the RB sets with PSFCH communications having the same COT status into groups containing contiguous RB sets. The UE may calculate a weighted priority value of each group and select the group with the lowest weighted priority value for transmission. In some aspects, the UE may perform energy measurements associated with each RB set to determine a likelihood of LBT success and may group the RB sets into groups of contiguous RB sets having the same energy level. The UE may calculate a weighted priority value of each group and select the group with the lowest weighted priority value for transmission.

In some aspects, the UE may use a common interlace to form a contiguous PSFCH transmission among RB sets.

Particular aspects of the subject matter described in this disclosure can be implemented to realize one or more of the following potential advantages.

In some examples, by performing an additional PSFCH selection process to drop PSFCH communications until a contiguous PSFCH transmission among RB sets is formed, some aspects may facilitate contiguous PSFCH transmission for UEs that do not support non-contiguous PSFCH transmission without introducing new operations, thereby improving network and/or device performance while minimizing complexity.

In some examples, by selecting PSFCH communications based on weighted priority values, some aspects may enable a configurable process of PSFCH communication selection/dropping that may be adaptable to favor selection of various PSFCH communications. In some examples, by using a weighted priority that is based on a quantity of PSFCH communications within each RB set (for example, so that RB sets having more PSFCH communications are prioritized) , some aspects may facilitate increasing the number of PSFCH communications that may be simultaneously transmitted, thereby improving network reliability.

In some examples, by grouping RB sets into groups containing contiguous RB sets and selecting a group based on a weighted priority value of the group, some aspects may facilitate more efficient selection of contiguous RB sets having PSFCH communications of higher priority (for example, lower priority value) , thereby improving network reliability and decreasing the likelihood of retransmission of higher-priority communications. In some aspects, by using a weighted priority that is based on a quantity of PSFCH communications within each RB set (for example, so that RB sets having more PSFCH communications are prioritized) , some aspects may facilitate increasing the number of PSFCH communications that may be simultaneously transmitted, thereby improving network reliability.

In some aspects, by first forming contiguous PSFCH transmissions among RB sets, and then performing PSFCH dropping only if the resulting contiguous RB sets exceed the UE capability, some aspects may facilitate maximizing the quantity of PSFCH communications that are transmitted, thereby improving network reliability. In some aspects, by selecting PSFCH communications based on COT status and/or energy level, some aspects may facilitate improving the likelihood of transmission of PSFCH communications through reliable sidelink channels.

Figure 1 is a diagram illustrating an example of a wireless network. The wireless network 100 may be or may include elements of a 5G (for example, NR) network or a 4G (for example, Long Term Evolution (LTE) ) network, among other examples. The wireless network 100 may include one or more network nodes 110 (shown as a network node (NN) 110a, a network node 110b, a network node 110c, and a network node 110d) , a UE 120 or multiple UEs 120 (shown as a UE 120a, a UE 120b, a UE 120c, a UE 120d, and a UE 120e) , or other network entities. A network node 110 is an entity that communicates with UEs 120. As shown, a network node 110 may include one or more network nodes. For example, a network node 110 may be an aggregated network node, meaning that the aggregated network node is configured to utilize a radio protocol stack that is physically or logically integrated within a single RAN node (for example, within a single device or unit) . As another example, a network node 110 may be a disaggregated network node (sometimes referred to as a disaggregated base station) , meaning that the network node 110 is configured to utilize a protocol stack that is physically or logically distributed among two or more nodes (such as one or more central units (CUs) , one or more distributed units (DUs) , or one or more radio units (RUs) ) .

In some examples, a network node 110 is or includes a network node that communicates with UEs 120 via a radio access link, such as an RU. In some examples, a network node 110 is or includes a network node that communicates with other network nodes 110 via a fronthaul link or a midhaul link, such as a DU. In some examples, a network node 110 is or includes a network node that communicates with other network nodes 110 via a midhaul link or a core network via a backhaul link, such as a CU. In some examples, a network node 110 (such as an aggregated network node 110 or a disaggregated network node 110) may include multiple network nodes, such as one or more RUs, one or more CUs, or one or more DUs. A network node 110 may include, for example, an NR network node, an LTE network node, a Node B, an eNB (for example, in 4G) , a gNB (for example, in 5G) , an access point, or a transmission reception point (TRP) , a DU, an RU, a CU, a mobility element of a network, a core network node, a network element, a network equipment, and/or a RAN node. In some examples, the network nodes 110 may be interconnected to one another or to one or more other network nodes 110 in the wireless network 100 through various types of fronthaul, midhaul, or backhaul interfaces, such as a direct physical connection, an air interface, or a virtual network, using any suitable transport network.

Each network node 110 may provide communication coverage for a particular geographic area. In the Third Generation Partnership Project (3GPP) , the term “cell” can refer to a coverage area of a network node 110 or a network node subsystem serving this coverage area, depending on the context in which the term is used.

A network node 110 may provide communication coverage for a macro cell, a pico cell, a femto cell, or another type of cell. A macro cell may cover a relatively large geographic area (for example, several kilometers in radius) and may allow unrestricted access by UEs 120 with service subscriptions. A pico cell may cover a relatively small geographic area and may allow unrestricted access by UEs 120 with service subscription. A femto cell may cover a relatively small geographic area (for example, a home) and may allow restricted access by UEs 120 having association with the femto cell (for example, UEs 120 in a closed subscriber group (CSG) ) . A network node 110 for a macro cell may be referred to as a macro network node. A network node 110 for a pico cell may be referred to as a pico network node. A network node 110 for a femto cell may be referred to as a femto network node or an in-home network node.

In some aspects, the terms “base station” or “network node” may refer to an aggregated base station, a disaggregated base station, an integrated access and backhaul (IAB) node, a relay node, or one or more components thereof. For example, in some aspects, “base station” or “network node” may refer to a CU, a DU, an RU, a Near-Real Time (Near-RT) RAN Intelligent Controller (RIC) , and/or a Non-Real Time (Non-RT) RIC. In some aspects, the terms “base station” or “network node” may refer to one device configured to perform one or more functions, such as those described herein in connection with the network node 110. In some aspects, the terms “base station” or “network node” may refer to a plurality of devices configured to perform the one or more functions. For example, in some distributed systems, each of a quantity of different devices (which may be located in the same geographic location or in different geographic locations) may be configured to perform at least a portion of a function, or to duplicate performance of at least a portion of the function, and the terms “base station” or “network node” may refer to any one or more of those different devices. In some aspects, the terms “base station” or “network node” may refer to one or more virtual base stations or one or more virtual base station functions. For example, in some aspects, two or more base station functions may be instantiated on a single device. In some aspects, the terms “base station” or “network node” may refer to one of the base station functions and not another. In this way, a single device may include more than one base station.

A network controller 130 may couple to or communicate with a set of network nodes 110 and may provide coordination and control for these network nodes 110. The network controller 130 may communicate with the network nodes 110 via a backhaul communication link. The network nodes 110 may communicate with one another directly or indirectly via a wireless or wireline backhaul communication link. In some aspects, the network controller 130 may be a CU or a core network device, or the network controller 130 may include a CU or a core network device.

The wireless network 100 may include one or more relay stations. A relay station is an entity that can receive a transmission of data from an upstream station (for example, a network node 110 or a UE 120) and send a transmission of the data to a downstream station (for example, a UE 120 or a network node 110) . A relay station may be a UE 120 that can relay transmissions for other UEs 120. In the example shown in Figure 1, the network node 110d (for example, a relay network node) may communicate with the network node 110a (for example, a macro network node) and the UE 120d in order to facilitate communication between the network node 110a and the UE 120d. A network node 110 that relays communications may be referred to as a relay station, a relay network node, or a relay.

The UEs 120 may be dispersed throughout the wireless network 100, and each UE 120 may be stationary or mobile. A UE 120 may include, for example, an access terminal, a terminal, a mobile station, or a subscriber unit. A UE 120 may be a cellular phone (for example, a smart phone) , a personal digital assistant (PDA) , a wireless modem, a wireless communication device, a handheld device, a laptop computer, a cordless phone, a wireless local loop (WLL) station, a tablet, a camera, a gaming device, a netbook, a smartbook, an ultrabook, a medical device, a biometric device, a wearable device (for example, a smart watch, smart clothing, smart glasses (for example, an augmented reality (AR) , virtual reality (VR) , mixed reality, or extended reality (XR) headset) , a smart wristband, smart jewelry (for example, a smart ring or a smart bracelet) ) , an entertainment device (for example, a music device, a video device, or a satellite radio) , a vehicular component or sensor, a smart meter/sensor, industrial manufacturing equipment, a global positioning system device, a UE function of a network node, or any other suitable device that is configured to communicate via a wireless medium. Some UEs 120 (for example, UEs 102a and 120e) may communicate directly using one or more sidelink channels (for example, without a network node as an intermediary to communicate with one another) .

Some UEs 120 may be considered machine-type communication (MTC) or evolved or enhanced machine-type communication (eMTC) UEs. An MTC UE or an eMTC UE may include, for example, a robot, a drone, a remote device, a sensor, a meter, a monitor, or a location tag, that may communicate with a network node, another device (for example, a remote device) , or some other entity. Some UEs 120 may be considered Internet-of-Things (IoT) devices, or may be implemented as NB-IoT (narrowband IoT) devices. Some UEs 120 may be considered a Customer Premises Equipment. A UE 120 may be included inside a housing that houses components of the UE 120, such as processor components or memory components. In some examples, the processor components and the memory components may be coupled together. For example, the processor components (for example, one or more processors) and the memory components (for example, a memory) may be operatively coupled, communicatively coupled, electronically coupled, or electrically coupled.

In some examples, two or more UEs 120 (for example, shown as UE 120a and UE 120e) may communicate directly using one or more sidelink channels (for example, without using a network node 110 as an intermediary to communicate with one another) . For example, the UEs 120 may communicate using peer-to-peer (P2P) communications, device-to-device (D2D) communications, a vehicle-to-everything (V2X) protocol (for example, which may include a vehicle-to-vehicle (V2V) protocol using for example a PC5 interface for direct communication, a vehicle-to-infrastructure (V2I) protocol, or a vehicle-to-pedestrian (V2P) protocol) , or a mesh network. In such examples, a UE 120 may perform scheduling operations, resource selection operations, or other operations described elsewhere herein as being performed by the network node 110. In other examples, the two or more UEs 120 may communicate through a vehicle-to-network-vehicle (V2N2V) protocol for example by communicating through a Uu interface using the LTE and/or NR uplink and downlink.

In some aspects, a UE (for example, the UE 120) may include a communication manager 140. As described in more detail elsewhere herein, the communication manager 140 may monitor at least one sidelink channel associated with an unlicensed spectrum for a plurality of sidelink communications; and transmit a subset of PSFCH communications, of a set of PSFCH communications, using a second plurality of RB sets that are contiguous in a frequency domain, wherein the second plurality of RB sets is selected from among a first plurality of RB sets corresponding to the set of PSFCH communications, and wherein the first plurality of RB sets is selected using a PSFCH selection process.

In some aspects, the communication manager 140 may monitor at least one sidelink channel associated with an unlicensed spectrum for a plurality of sidelink communications; and transmit a subset of PSFCH communications, of a set of PSFCH communications, using a second plurality of RB sets selected, using a group-based selection operation, from among a first plurality of RB sets corresponding to the set of PSFCH communications associated with the plurality of sidelink communications.

In some aspects, the communication manager 140 may monitor at least one sidelink channel associated with an unlicensed spectrum for a plurality of sidelink communications; and transmit, in a non-contiguous plurality of RB sets, a set of PSFCH communications associated with the plurality of sidelink communications, wherein at least one RB set of the plurality of RB sets omits a PSFCH communication, and wherein transmitting the set of PSFCH communications comprises transmitting a common interlace in the at least one RB set, wherein the common interlace is associated with the set of PSFCH communications. Additionally or alternatively, the communication manager 140 may perform one or more other operations described herein.

Figure 2 is a diagram illustrating an example UE 120a in communication with a UE 120e in a wireless network. The UE 120a and/or the UE 120e may correspond to the UE 120 of Figure 1. The UE 120a may be equipped with a set of antennas 202 (shown as antennas 202a through 202r) , such as R antennas (R ≥ 1) . The set of antennas 202 may include, or may be included within, one or more antenna panels, one or more antenna groups, one or more sets of antenna elements, or one or more antenna arrays, among other examples. An antenna panel, an antenna group, a set of antenna elements, or an antenna array may include one or more antenna elements (within a single housing or multiple housings) , a set of coplanar antenna elements, a set of non-coplanar antenna elements, or one or more antenna elements coupled to one or more transmission or reception components, such as one or more components of Figure 2.

At the UE 120a, the set of antennas 202 may receive sidelink signals from the UE 120e and/or other UEs 120 and may provide a set of received signals (for example, R received signals) to a set of modems 204 (for example, R modems) , shown as modems 204a through 204r. For example, each received signal may be provided to a demodulator component (shown as DEMOD) of a modem 204. Each modem 204 may use a respective demodulator component to condition (for example, filter, amplify, downconvert, or digitize) a received signal to obtain input samples. Each modem 204 may use a demodulator component to further process the input samples (for example, for OFDM) to obtain received symbols. A MIMO detector 206 may obtain received symbols from the modems 204, may perform MIMO detection on the received symbols if applicable, and may provide detected symbols. A receive processor 208 may process (for example, demodulate and decode) the detected symbols, may provide decoded data for the UE 120a to a data sink 210, and may provide decoded control information and system information to a controller/processor 212. The term “controller/processor” may refer to one or more controllers and/or one or more processors. A channel processor may determine a reference signal received power (RSRP) parameter, a received signal strength indicator (RSSI) parameter, a reference signal received quality (RSRQ) parameter, or a channel quality information (CQI) parameter, among other examples. In some examples, one or more components of the UE 120a may be included in a housing 214.

A transmit processor 216 may receive and process data from a data source 218 and control information (for example, for reports that include RSRP, RSSI, RSRQ, or CQI) from the controller/processor 212. The transmit processor 216 may generate reference symbols for one or more reference signals. The symbols from the transmit processor 216 may be precoded by a transmit (TX) MIMO processor 220 if applicable, further processed by the modems 204 (for example, for DFT-s-OFDM or CP-OFDM) , and transmitted to the UE 120e. In some examples, the modem 204 of the UE 120a may include a modulator and a demodulator. In some examples, the UE 120a includes a transceiver. The transceiver may include any combination of the antenna (s) 202, the modem (s) 204, the MIMO detector 206, the receive processor 208, the transmit processor 216, or the TX MIMO processor 220. The transceiver may be used by a processor (for example, the controller/processor 212) and a memory 222 to perform aspects of any of the methods described herein. In some examples, the controller/processor 212 represents one or more processors and the memory 222 represents one or more memories.

The controller/processor 212 of the UE 120a, or any other component (s) of Figure 2 may perform one or more techniques associated with PSFCH transmissions for non-contiguous RB sets in unlicensed sidelink communications, as described in more detail elsewhere herein. For example, the controller/processor 212 of the UE 120a, or any other component (s) of Figure 2 may perform or direct operations of, for example, process 800 of Figure 8, process 900 of Figure 9, process 1000 of Figure 10, or other processes as described herein. The memory 222 may store data and program codes for the UE 120a. In some examples, the memory 222 may include a non-transitory computer-readable medium storing one or more instructions (for example, code or program code) for wireless communication. For example, the one or more instructions, when executed (for example, directly, or after compiling, converting, or interpreting) by one or more processors of the UE 120a, may cause the one or more processors and/or the UE 120a to perform or direct operations of, for example, process 800 of Figure 8, process 900 of Figure 9, process 1000 of Figure 10, or other processes as described herein. In some examples, executing instructions may include running the instructions, converting the instructions, compiling the instructions, or interpreting the instructions, among other examples. In some implementations, one or more of the multiple memories may be configured to store processor-executable code that, when executed, may configure the one or more processors to perform various functions described herein (as part of a processing system) . In some other implementations, the processing system may be pre-configured to perform various functions described herein.

In some aspects, an individual processor may perform all of the functions described as being performed by one or more processors. In some aspects, one or more processors may collectively perform (or be configured or operable to perform) a set of functions. For example, a first set of (one or more) processors of the one or more processors may perform a first function described as being performed by the one or more processors, and a second set of (one or more) processors of the one or more processors may perform a second function described as being performed by the one or more processors. The first set of processors and the second set of processors may be the same set of processors or may be different sets of processors. Reference to “one or more processors” should be understood to refer to any one or more of the processors described in connection with Figure 2. Reference to “one or more memories” should be understood to refer to any one or more memories of a corresponding device, such as the memory described in connection with Figure 2. For example, functions described as being performed by one or more memories can be performed by the same subset of the one or more memories or different subsets of the one or more memories.

In some aspects, a UE (for example, the UE 120a) includes means for monitoring at least one sidelink channel associated with an unlicensed spectrum for a plurality of sidelink communications; and/or means for transmitting a subset of PSFCH communications, of a set of PSFCH communications, using a second plurality of RB sets that are contiguous in a frequency domain, wherein the second plurality of RB sets is selected from among a first plurality of RB sets corresponding to the set of PSFCH communications, and wherein the first plurality of RB sets is selected using a PSFCH selection process.

In some aspects, the UE includes means for monitoring at least one sidelink channel associated with an unlicensed spectrum for a plurality of sidelink communications; and/or means for transmitting a subset of PSFCH communications, of a set of PSFCH communications, using a second plurality of RB sets selected, using a group-based selection operation, from among a first plurality of RB sets corresponding to the set of PSFCH communications associated with the plurality of sidelink communications.

In some aspects, the UE includes means for monitoring at least one sidelink channel associated with an unlicensed spectrum for a plurality of sidelink communications; and/or means for transmitting, in a non-contiguous plurality of RB sets, a set of PSFCH communications associated with the plurality of sidelink communications, wherein at least one RB set of the plurality of RB sets omits a PSFCH communication, and wherein transmitting the set of PSFCH communications comprises transmitting a common interlace in the at least one RB set, wherein the common interlace is associated with the set of PSFCH communications. The means for the UE to perform operations described herein may include, for example, one or more of communication manager 140, antenna 202, modem 204, MIMO detector 206, receive processor 208, transmit processor 216, TX MIMO processor 220, controller/processor 212, or memory 222.

Figure 3 is a diagram illustrating an example 300 of sidelink communications.

As shown in Figure 3, a first UE 305-1 may communicate with a second UE 305-2 (and one or more other UEs 305) via one or more sidelink channels 310. The UEs 305-1 and 305-2 may communicate using the one or more sidelink channels 310 for P2P communications, D2D communications, V2X communications (for example, which may include V2V communications, V2I communications, and/or V2P communications) and/or mesh networking. In some examples, the UEs 305 (for example, UE 305-1 and/or UE 305-2) may correspond to one or more other UEs described elsewhere herein, such as UE 120. In some examples, the one or more sidelink channels 310 may use a PC5 interface and/or may operate in a high frequency band (for example, the 5.9 GHz band) . Additionally or alternatively, the UEs 305 may synchronize timing of transmission time intervals (TTIs) (for example, frames, subframes, slots, or symbols) using global navigation satellite system (GNSS) timing.

As further shown in Figure 3, the one or more sidelink channels 310 may include a PSCCH 315, a PSSCH 320, and/or a PSFCH 325. The PSCCH 315 may be used to communicate control information, similar to a physical downlink control channel (PDCCH) and/or a physical uplink control channel (PUCCH) used for cellular communications with a network node 110 via an access link or an access channel. The PSSCH 320 may be used to communicate data. For example, the PSCCH 315 may carry sidelink control information (SCI) 330, which may indicate various control information used for sidelink communications, such as one or more resources (for example, time resources, frequency resources, and/or spatial resources) where a transport block (TB) 335 may be carried on the PSSCH 320. The TB 335 may include data. The PSFCH 325 may be used to communicate sidelink feedback 340, such as HARQ feedback (for example, acknowledgement or negative acknowledgement (ACK/NACK) information) , transmit power control (TPC) , and/or a scheduling request (SR) . For example, the UE 305-1, which may be a responding UE, may receive HARQ feedback (such as an ACK or a NACK) from the UE 305-1, which may be a COT initiating UE. The HARQ feedback may be received via one or more PSFCH transmission occasions associated with the PSFCH 325.

Although shown on the PSCCH 315, in some examples, the SCI 330 may include multiple communications in different stages, such as a first stage SCI (SCI-1) and a second stage SCI (SCI-2) . The SCI-1 may be transmitted on the PSCCH 315. The SCI-2 may be transmitted on the PSSCH 320. The SCI-1 may include, for example, an indication of one or more resources (for example, time resources, frequency resources, and/or spatial resources) on the PSSCH 320, information for decoding sidelink communications on the PSSCH, a quality of service (QoS) priority value, a resource reservation period, a PSSCH demodulation reference signal (DMRS) pattern, an SCI format for the SCI-2, a beta offset for the SCI-2, a quantity of PSSCH DMRS ports, and/or a modulation and coding scheme (MCS) . The SCI-2 may include information associated with data transmissions on the PSSCH 320, such as a HARQ process ID, a new data indicator (NDI) , a source identifier, a destination identifier, and/or a channel state information (CSI) report trigger.

In some examples, the one or more sidelink channels 310 may use resource pools. For example, a scheduling assignment (for example, included in SCI 330) may be transmitted in sub-channels using specific RBs across time. In some examples, data transmissions (for example, on the PSSCH 320) associated with a scheduling assignment may occupy adjacent RBs in the same subframe as the scheduling assignment (for example, using frequency division multiplexing) . In some examples, a scheduling assignment and associated data transmissions are not transmitted on adjacent RBs.

In some examples, a UE 305 may operate using a sidelink transmission mode (for example, Mode 1) where resource selection and/or scheduling is performed by a network node 110 (for example, a base station, a CU, or a DU) . For example, the UE 305 may receive a grant (for example, in downlink control information (DCI) or in a radio resource control (RRC) message, such as for configured grants) from the network node 110 (for example, directly or via one or more network nodes) for sidelink channel access and/or scheduling. In some examples, a UE 305 may operate using a transmission mode (for example, Mode 2) where resource selection and/or scheduling is performed by the UE 305 (for example, rather than a network node 110) . In some examples, the UE 305 may perform resource selection and/or scheduling by sensing channel availability for transmissions. For example, the UE 305 may measure an RSSI parameter (for example, a sidelink-RSSI (S-RSSI) parameter) associated with various sidelink channels, may measure an RSRP parameter (for example, a PSSCH-RSRP parameter) associated with various sidelink channels, and/or may measure an RSRQ parameter (for example, a PSSCH-RSRQ parameter) associated with various sidelink channels, and may select a channel for transmission of a sidelink communication based at least in part on the measurement (s) .

Additionally or alternatively, the UE 305 may perform resource selection and/or scheduling using SCI 330 received in the PSCCH 315, which may indicate occupied resources and/or channel parameters. Additionally or alternatively, the UE 305 may perform resource selection and/or scheduling by determining a channel busy ratio (CBR) associated with various sidelink channels, which may be used for rate control (for example, by indicating a maximum number of resource blocks that the UE 305 can use for a particular set of subframes) .

In the transmission mode where resource selection and/or scheduling is performed by a UE 305, the UE 305 may generate sidelink grants, and may transmit the grants in SCI 330. A sidelink grant may indicate, for example, one or more parameters (for example, transmission parameters) to be used for an upcoming sidelink transmission, such as one or more resource blocks to be used for the upcoming sidelink transmission on the PSSCH 320 (for example, for TBs 335) , one or more subframes to be used for the upcoming sidelink transmission, and/or an MCS to be used for the upcoming sidelink transmission. In some examples, a UE 305 may generate a sidelink grant that indicates one or more parameters for semi-persistent scheduling (SPS) , such as a periodicity of a sidelink transmission. Additionally or alternatively, the UE 305 may generate a sidelink grant for event-driven scheduling, such as for an on-demand sidelink message.

Figure 4 is a diagram illustrating an example 400 of a PSFCH waveform. The PSFCH waveform may be associated with a PSFCH transmission with 15 kilohertz (kHz) sub-carrier spacing (SCS) or 30 kHz SCS. In a first example, each PSFCH transmission may occupy a single common interlace and K3 dedicated PRBs. A value of K3 may be configured (for example, pre-configured) at the UE. For example, K3 may be equal to 1, 2, or 5, among other examples. The K3 dedicated PRBs may be located on the same interlace. In some examples, there may be one or more guard band PRBs between a common PRB and a dedicated PRB. On the K3 dedicated PRBs, multiple cyclic shift (CS) pairs may be used (for example, as in legacy NR sidelink (SL) PSFCH transmission) . When a PRB of the common interlace and a dedicated PRB are located within a same 1 megahertz (MHz) bandwidth, the UE may only transmit on the dedicated PRB (subject to meeting occupied channel bandwidth (OCB) requirements) . In a second example, each PSFCH transmission may occupy a single dedicated interlace. PSSCH transmissions on non-overlapped resources may be mapped to orthogonal dedicated PRBs for PSFCH transmission.

Example 400 is an example of a unified framework between the first example (where a PSFCH transmission occupies a common interlace 402 and K3 dedicated PRBs) and the second example (where a PSFCH transmission occupies a single dedicated interlace 404) . A configurable number (for example, K3) of contiguous ACK/NACK carrying PRBs 404 may be transmitted on a non-common interlace 404 and N K3 dummy PSFCH interlace resource blocks (IRBs) may be transmitted on the common interlace 402. N may be equal to the number of IRBs in one interlace. The PSFCH waveform may become a full interlaced PSFCH waveform in accordance with K3 being equal to N (K3 =N) . In some examples, configuring more than one ACK/NACK carrying IRB may resolve a low transmit power issue that occurs due to a power spectral density (PSD) limit and a near-far problem. As shown in Figure 4, a UE may have two ACK/NACK carrying RBs 404. A CS ramping offset 406 of five CS resources may be used to reduce a peak-to-average power ratio (PAPR) . Dummy IRBs 408 that are within X RBs of the ACK/NACK carrying IRBs may be dropped in order to maintain the ACK/NACK transmit power under the PSD limit. The UE and another PSFCH transmitting UE may transmit on reserved (R) cyclic resources in the dummy IRBs on the common interlace, for example, to fulfill the OCB.

Figure 5 is a diagram illustrating an example 500 of simultaneous PSFCH transmission.

In some examples, a UE can support PSFCH transmission over contiguous and non-contiguous RB sets. A UE can indicate a UE capability for supporting PSFCH transmissions over contiguous RB sets and/or a UE capability for supporting PSFCH transmissions over non-contiguous RB sets. In some examples, each PSFCH transmission can occupy one common interlace and K3 dedicated PRBs. The cyclic shift on each PRB of the K3 dedicated PRB (s) can be the same. In some examples, the cyclic shift on each PRB of a common interlace can be determined according to a UE implementation.

In some examples, PSFCH can be transmitted over non-contiguous RB sets. For example, PSFCH communications associated with different links in different RB sets can be transmitted simultaneously. The support of PSFCH transmission over non-contiguous RB sets is subject to UE capability. Additionally, due to a UE’s capability, there can be a limit on the maximum number of PSFCH communications that can be simultaneously transmitted by the UE. In some examples, when the number of simultaneous PSFCH communications exceed the UE capability, the UE can select the PSFCH communications to be transmitted by performing a PSFCH selection process (which may, in some examples, be referred to as simultaneous PSFCH transmission) . The UE may perform the PSFCH selection process by selecting PSFCH communications based on information carried by the respective PSFCH communication, HARQ-ACK first, conflict indication second, and/or an ascending order of a priority value for information carried by respective PSFCH communications. For example, the PSFCH selection process may be performed by dropping unselected PSFCH communications.

Since the simultaneously transmitted PSFCH communications are associated with different links, the PSFCH communications may be associated with non-contiguous RB sets (shown as “RB set #0, ” “RB set #1, ” “RB set #2, ” and “RB set #3” in Figure 5) . When the number of simultaneous PSFCH communications exceeds the UE capability, the UE can select the PSFCH communications, as described above. As shown by reference number 505, the outcome of PSFCH selection may be still non-contiguous and thus, a UE that does not support PSFCH transmission over non-contiguous RB sets may be unable to transmit one or more of the PSFCH communications.

Some aspects of the techniques described herein may facilitate PSFCH transmissions for non-contiguous RB sets. In some aspects, for example, a UE may perform the PSFCH selection process described above to select PSFCH communications (for example, buy dropping one or more PSFCH communications) . If the remaining PSFCH communications are still located at non-contiguous RB sets, the UE may continue to drop PSFCH communications based on one or more rules until the remaining PSFCH communications are associated with contiguous RB sets. In some aspects, the UE may first perform PSFCH dropping operations to form a contiguous PSFCH transmission among RB sets. If the PSFCH communication (s) in the resulting contiguous RB sets exceed the UE capability, then the UE may performs PSFCH dropping to select the PSFCH communications for transmission. In some aspects, the UE may use a common interlace to form a contiguous PSFCH transmission among RB sets.

Figures 6A-6C are diagrams illustrating examples 600, 612, and 614 associated with PSFCH transmissions for non-contiguous resource block sets in unlicensed sidelink communications. As shown, a UE 602 may communicate with one or more additional UEs 604a, 604b, 604c, and 604d. The UE 602 may be, be similar to, include, or be included in, the UE 102 and/or 102a depicted in Figs. 1 and 2.

As shown in Figure 6A, in a first operation 606, the UE 602 may monitor at least one sidelink channel. For example, the UE 602 may monitor at least one sidelink channel associated with an unlicensed spectrum for a plurality of sidelink communications 608. In a second operation 610, the UE 602 may transmit a subset of PSFCH communications of a set of PSFCH communications. In some aspects, the UE 602 may transmit the subset of PSFCH communications simultaneously using a second plurality of RB sets that are contiguous in a frequency domain. In some aspects, the second plurality of RB sets is selected from among a first plurality of RB sets corresponding to the set of PSFCH communications. In some aspects, the first plurality of RB sets may be selected using an initial PSFCH selection process. The UE 602 may perform the initial PSFCH selection process by selecting PSFCH communications based on information carried by the PSFCH. For example, the UE 602 may first select PSFCH communications with HARQ-ACK information from the set 612 of PSFCH communications corresponding to the smallest priority values and then the UE 602 may select PSFCH communications with conflict information corresponding to the smallest remaining priority values. Accordingly, the UE 602 may perform the initial PSFCH selection process by dropping one PSFCH communication at a time (e.g., PSFCH communication dropping may be performed at the PSFCH level) .

In some aspects, the second plurality 614 of RB sets may be selected using an additional PSFCH selection process. The additional PSFCH selection process, in some aspects, may be a continuation of the initial PSFCH selection process (e.g., the additional PSFCH selection process may include PSFCH dropping performed at the PSFCH level) . For example, the UE 602 may continue selecting PSFCH communications (e.g., by dropping unselected PSFCH communications) in accordance with the initial PSFCH selection process described above until a contiguous PSFCH transmission among RB sets is formed.

In some aspects, the second plurality of RB sets may be selected by dropping PSFCH communications at the RB set level. For example, the UE 602 may drop entire RB sets (and any PSFCH communications therein) based on a selection process. For example, in some aspects, the second plurality of RB sets may be selected using a set of weighted priority values. Each weighted priority value of the set of weighted priority values may be a weighted priority value, Priority_weighted, corresponding to an RB set. The weighted priority value, Pruirity_weighted, corresponding to an RB set may be associated with priority values associated with respective PSFCH communication of the RB set. For example, in some aspects, the weighted priority value may be calculated using Priority_weighted=∑_ia_iPSFCH_i. The second plurality of RB sets may include a first RB set having a first weighted priority value of the set of weighted priority values, and the second plurality of RB sets may omit a second RB set having a second weighted priority value of the set of weighted priority values based on the second weighted priority value being higher than the first weighted priority value.

In some aspects, as shown in Figure 6B by example 612, the weighted priority values may include average priority values of two or more priority values corresponding, respectively, to two or more PSFCH communications 616 and 618, of the set 620 of PSFCH communications, associated with each RB set. For example, the weighted priority value associated with RB set#0 is the average of the priority value associated with PSFCH communication 616 and the priority value associated with PSFCH communication 618. Thus, the weighted priority value associated with RB set#0 is 1.5, which is greater than 1, and, as shown by illustrative transmission 622, the RB set#0 may be dropped, leaving only RB set#3 and PSFCH communication 624.

In some aspects, the weighted priority value may include a highest priority value (and, thus a lowest priority level) of two or more priority values corresponding, respectively, to two or more PSFCH communications, of the set 620 of PSFCH communications, associated with the first RB set. Thus, in example 612, the weighted priority value associated with RB set#0 is 2, which is greater than 1, resulting in the dropping of the RB set#0, leaving the illustrative transmission 622. In some aspects, the weighted priority value associated with an RB set may include a lowest priority value (e.g., a highest priority level) of two or more priority values corresponding, respectively, to two or more PSFCH communications, of the set 620 of PSFCH communications, associated with the first RB set.

In some aspects, keeping RB sets with more PSFCH communications than other RB sets may be preferable. A function may be used to produce weighted priority values such that RB sets with more PSFCH communications have lower priority values (and, thus, higher priority levels) . In some aspects, for example, the weighted priority value associated with an RB set may include a function of two or more priority values corresponding, respectively, to two or more PSFCH communications, of the PSFCH communications in the RB set. For example, the function may include a product of a second weighted priority value (for example, an average weighted priority value) associated with the first RB set and a quantity of PSFCH communications associated with the first RB set. For example, in some aspects, a_i=b_ic_i. Thus, in example 612, where b1, b2, and b3, corresponding respectively to PSFCH communication 618, 616, and 624, may equal 1/2, 1/2, and 1, respectively (to provide the average priority value across the PSFCH communications in the respective groups) , and c1, c2, and c3 may equal 1/2, 1/2, and 1, respectively. Thus, the weighted priority value associated with RB set#0 may be 2*1/2*1/2 + 1*1/2*1/2 = 3/4 = 0.75, which is less than 1 (the weighted priority value associated with RB set#3) , and therefore, the RB set#3 may be dropped, resulting in the illustrative transmission 626.

In some aspects, the second plurality of RB sets may be selected based on a selection of a first group 628 of contiguous RB sets, of the first plurality of RB sets, using a set of weighted priority values. In some aspects, each weighted priority value of the set of weighted priority values may be associated with a respective group of contiguous RB sets 628 or 630. The second plurality of RB sets may include the first group 628 of contiguous RB sets, and may omit a second group 630 of contiguous RB sets set having a second weighted priority value of the set of weighted priority values based on the second weighted priority value being higher than the first weighted priority value. In some aspects, the first weighted priority value may include a function of two or more priority values corresponding, respectively, to two or more RB sets of the first group 628 of contiguous RB sets, and the function may be associated with a quantity of PSFCH communications associated with the first group 628 of contiguous RB sets. For example, in some aspects, a_i=b_ic_i. Thus, for example, as shown in Figure 6C, b1, b2, b3, and b4, corresponding to PSFCH set 632, 634, 636, and 638, respectively, may equal 1, 1/3, 1/3, and 1/3, respectively (to provide the average priority value across the PSFCH communications in the respective groups) , and c1, c2, and c3 may equal 1, 1/3, 1/3, and 1/3, respectively. Thus, the weighted priority value associated with the first group 628 is equal to 4*1/3*1/3 + 2*1/3*1/3 + 1*1/3*1/3 = 7/9 (approximately 0.78) , which is less than 2 and, therefore, the second group 630 of RB sets may be dropped, resulting in the illustrative transmission 640.

In some aspects, the UE may form a contiguous PSFCH transmission across RB sets and, if the transmission includes more PSFCH communications than the UE supports, the UE may drop one or more of the PSFCH communications until the quantity of PSFCH communications is within the UE capability.

Figures 7A-7C are diagrams illustrating examples 700, 702, and 704 associated with PSFCH transmissions for non-contiguous resource block sets in unlicensed sidelink communications. Example 700 illustrates examples associated with the signaling of the UE 602 depicted in Figure 6A.

In some aspects, the second plurality of RB sets may be selected, using a group-based selection operation, from among a first plurality 706 of RB sets corresponding to the set of PSFCH communications associated with the plurality of sidelink communications. For example, the second plurality of RB sets may be selected based on a selection of a first group 708 of contiguous RB sets, of the first plurality 706 of RB sets, using a set of weighted priority values. Each weighted priority value of the set of weighted priority values may be associated with a respective group of contiguous RB sets. The second plurality of RB sets may include the first group 708 of contiguous RB sets, and may omit a second group 710 of contiguous RB sets set having a second weighted priority value of the set of weighted priority values based on the second weighted priority value being higher than a first weighted priority value, thereby resulting in the illustrative transmission 712.

In some aspects, the first group 708 of contiguous RB sets may include at least two RB sets, where each RB set of the at least two RB sets is associated with an equivalent COT status. In some aspects, the first group of contiguous RB sets may include at least two RB sets, where each RB set of the at least two RB sets may be associated with an equivalent energy level. In some aspects, the equivalent energy level may include an RSSI and/or an RSRP. In some aspects, an indication of the equivalent energy level may be maintained in one or more memories of the UE 602 (for example, as a result of being specified in a wireless communication standard) and/or provided to the UE 602 via an RRC message.

In some aspects, the second plurality of RB sets may be further based on a PSFCH dropping operation associated with a third plurality 714 of RB sets, where the third plurality 714 of RB sets is selected from among the first plurality of RB sets using the group-based selection operation. In some aspects, the second plurality of RB sets may omit at least one RB set of the third plurality 714 of RB sets based on the at least one RB set comprising an outermost RB set of the third plurality of RB sets. For example, as shown by example 702 in Figure 7B, the UE 602 may drop PSFCH#4, which has a priority value of 3, resulting in the illustrative communication 716.

In some aspects, each RB set of the second plurality of RB sets may include an initial PSFCH communication, where the initial PSFCH communication has a lowest priority value of at least one priority value associated with the RB set, and where the subset of PSFCH communications omits at least one PSFCH communication of the set of PSFCH communications in association with the at least one PSFCH communication having a highest priority value of at least two priority values associated with an RB set of the second plurality of RB sets. The initial PSFCH communication may be referred to, for example, as a “specific” PSFCH. Each RB set may have a specific PSFCH, which may be the PSFCH communication having a lowest priority value. In some aspects, the specific PSFCH communication is not dropped, whereas non-specific PSFCH communications may be dropped as described herein. In some aspects, as further shown in example 702 of Figure 7B, PSFCH#1, PSFCH#3, PSFCH#4 may be specific PSFCHs, and the UE 602 may drop PSFCH#2 (priority value = 4) , resulting in the illustrative transmission 718. In some aspects, s PSFCH communication may be established as a specific PSFCH for RB sets other than the edge of contiguous RB sets.

In some aspects, the subset of PSFCH communications may omit at least one PSFCH communication of the set of PSFCH communications in association with the at least one PSFCH communication having a highest weighted priority value of at least two weighted priority values associated with the second plurality of RB sets. In some aspects, the at least one PSFCH communication has the highest weighted priority value based on the at least one PSFCH communication being associated with an outermost RB set of a third plurality 714 of RB sets. For example, in Figure 7B, PSFCH#2 and PSFCH#3 may be prioritized and PSFCH#4 may be dropped, resulting in the illustrative transmission 716. The third plurality of RB sets may be selected from among the first plurality of RB sets using the group-based selection operation.

In some aspects, as shown by example 704 in Figure 7C, the at least one RB set of the plurality of RB sets omits a PSFCH communication, and the UE 602 may transmit a common interlace in the at least one RB set (e.g., RB set#1 in example 704) . In some aspects, transmitting the common interlace in the at least one RB set may include transmitting the common interlace in the at least one RB set in accordance with configuration information. The configuration information may be maintained in one or more memories of the UE 602 (for example, as a result of being specified by a wireless communication standard) and/or provided to the UE 602 via an RRC message.

Figure 8 is a flowchart illustrating an example process 800 performed, for example, at a UE or an apparatus of a UE that supports simultaneous PSFCH transmission in accordance with the present disclosure. Example process 800 is an example where the apparatus or the UE (for example, UE 602) performs operations associated with PSFCH transmissions for non-contiguous RB sets in unlicensed sidelink communications.

As shown in Figure 8, in some aspects, process 800 may include monitoring at least one sidelink channel associated with an unlicensed spectrum for a plurality of sidelink communications (block 810) . For example, the UE (such as by using communication manager 1108 or reception component 1102, depicted in Figure 11) may monitor at least one sidelink channel associated with an unlicensed spectrum for a plurality of sidelink communications, as described above.

As further shown in Figure 8, in some aspects, process 800 may include transmitting a subset of PSFCH communications, of a set of PSFCH communications, using a second plurality of RB sets that are contiguous in a frequency domain, wherein the second plurality of RB sets is selected from among a first plurality of RB sets corresponding to the set of PSFCH communications, and wherein the first plurality of RB sets is selected using an initial PSFCH selection process (block 820) . For example, the UE (such as by using communication manager 1108 or transmission component 1104, depicted in Figure 11) may transmit a subset of PSFCH communications, of a set of PSFCH communications, using a second plurality of RB sets that are contiguous in a frequency domain, wherein the second plurality of RB sets is selected from among a first plurality of RB sets corresponding to the set of PSFCH communications, and wherein the first plurality of RB sets is selected using an initial PSFCH selection process, as described above.

Process 800 may include additional aspects, such as any single aspect or any combination of aspects described below or in connection with one or more other processes described elsewhere herein.

In a first additional aspect, the second plurality of RB sets is selected using an additional PSFCH selection process, wherein the additional PSFCH selection process comprises a continuation of the initial PSFCH selection process.

In a second additional aspect, alone or in combination with the first aspect, the second plurality of RB sets is selected using a set of weighted priority values, and each weighted priority value of the set of weighted priority values is associated with a respective PSFCH communication of the set of PSFCH communications.

In a third additional aspect, alone or in combination with one or more of the first and second aspects, the second plurality of RB sets comprises a first RB set having a first weighted priority value of the set of weighted priority values, the second plurality of RB sets omits a second RB set having a second weighted priority value of the set of weighted priority values, and the second weighted priority value is higher than the first weighted priority value.

In a fourth additional aspect, alone or in combination with one or more of the first through third aspects, the first weighted priority value comprises an average priority value of two or more priority values corresponding, respectively, to two or more PSFCH communications, of the set of PSFCH communications, associated with the first RB set.

In a fifth additional aspect, alone or in combination with one or more of the first through fourth aspects, the first weighted priority value comprises a highest priority value of two or more priority values corresponding, respectively, to two or more PSFCH communications, of the set of PSFCH communications, associated with the first RB set.

In a sixth additional aspect, alone or in combination with one or more of the first through fifth aspects, the first weighted priority value comprises a lowest priority value of two or more priority values corresponding, respectively, to two or more PSFCH communications, of the set of PSFCH communications, associated with the first RB set.

In a seventh additional aspect, alone or in combination with one or more of the first through sixth aspects, the first weighted priority value comprises a function of two or more priority values corresponding, respectively, to two or more PSFCH communications, of the set of PSFCH communications and associated with the first RB set, wherein the function comprises a product of a second weighted priority value associated with the first RB set and a quantity of PSFCH communications associated with the first RB set.

In an eighth additional aspect, alone or in combination with one or more of the first through seventh aspects, the second plurality of RB sets is selected based on a selection of a first group of contiguous RB sets, of the first plurality of RB sets, using a set of weighted priority values, and each weighted priority value of the set of weighted priority values is associated with a respective group of contiguous RB sets.

In a ninth additional aspect, alone or in combination with one or more of the first through eighth aspects, the second plurality of RB sets comprises the first group of contiguous RB sets, the second plurality of RB sets omits a second group of contiguous RB sets set having a second weighted priority value of the set of weighted priority values, and the second weighted priority value is higher than a first weighted priority value.

In a tenth additional aspect, alone or in combination with one or more of the first through ninth aspects, a first weighted priority value comprises a function of two or more priority values corresponding, respectively, to two or more RB sets of the first group of contiguous RB sets, wherein the function is associated with a quantity of PSFCH communications associated with the first group of contiguous RB sets.

Although Figure 8 shows example blocks of process 800, in some aspects, process 800 may include additional blocks, fewer blocks, different blocks, or differently arranged blocks than those depicted in Figure 8. Additionally or alternatively, two or more of the blocks of process 800 may be performed in parallel.

Figure 9 is a flowchart illustrating an example process 900 performed, for example, at a UE or an apparatus of a UE that supports simultaneous PSFCH transmission in accordance with the present disclosure. Example process 900 is an example where the apparatus or the UE (for example, UE 602) performs operations associated with PSFCH transmissions for non-contiguous resource block sets.

As shown in Figure 9, in some aspects, process 900 may include monitoring at least one sidelink channel associated with an unlicensed spectrum for a plurality of sidelink communications (block 910) . For example, the UE (such as by using communication manager 1108 or reception component 1102, depicted in Figure 11) may monitor at least one sidelink channel associated with an unlicensed spectrum for a plurality of sidelink communications, as described above.

As further shown in Figure 9, in some aspects, process 900 may include transmitting a subset of PSFCH communications, of a set of PSFCH communications, using a second plurality of RB sets selected, using a group-based selection operation, from among a first plurality of RB sets corresponding to the set of PSFCH communications associated with the plurality of sidelink communications (block 920) . For example, the UE (such as by using communication manager 1108 or transmission component 1104, depicted in Figure 11) may transmit a subset of PSFCH communications, of a set of PSFCH communications, using a second plurality of RB sets selected, using a group-based selection operation, from among a first plurality of RB sets corresponding to the set of PSFCH communications associated with the plurality of sidelink communications, as described above.

Process 900 may include additional aspects, such as any single aspect or any combination of aspects described below or in connection with one or more other processes described elsewhere herein.

In a first additional aspect, the second plurality of RB sets is selected based on a selection of a first group of contiguous RB sets, of the first plurality of RB sets, using a set of weighted priority values, and each weighted priority value of the set of weighted priority values is associated with a respective group of contiguous RB sets.

In a second additional aspect, alone or in combination with the first aspect, the second plurality of RB sets comprises the first group of contiguous RB sets, the second plurality of RB sets omits a second group of contiguous RB sets set having a second weighted priority value of the set of weighted priority values, and the second weighted priority value is higher than a first weighted priority value.

In a third additional aspect, alone or in combination with one or more of the first and second aspects, the first group of contiguous RB sets comprises at least two RB sets, wherein each RB set of the at least two RB sets is associated with an equivalent COT status.

In a fourth additional aspect, alone or in combination with one or more of the first through third aspects, the first group of contiguous RB sets comprises at least two RB sets, wherein each RB set of the at least two RB sets is associated with an equivalent energy level.

In a fifth additional aspect, alone or in combination with one or more of the first through fourth aspects, the equivalent energy level comprises a received signal strength indicator.

In a sixth additional aspect, alone or in combination with one or more of the first through fifth aspects, the equivalent energy level comprises a reference signal received power.

In a seventh additional aspect, alone or in combination with one or more of the first through sixth aspects, an indication of the equivalent energy level is maintained in one or more memories of the UE.

In an eighth additional aspect, alone or in combination with one or more of the first through seventh aspects, process 900 includes receiving a radio resource control message indicative of the equivalent energy level.

In a ninth additional aspect, alone or in combination with one or more of the first through eighth aspects, the second plurality of RB sets is further based on a PSFCH dropping operation associated with a third plurality of RB sets, wherein the third plurality of RB sets is selected from among the first plurality of RB sets using the group-based selection operation.

In a tenth additional aspect, alone or in combination with one or more of the first through ninth aspects, the second plurality of RB sets omits at least one RB set of the third plurality of RB sets based on the at least one RB set comprising an outermost RB set of the third plurality of RB sets.

In an eleventh additional aspect, alone or in combination with one or more of the first through tenth aspects, each RB set of the second plurality of RB sets comprises an initial PSFCH communication, wherein the initial PSFCH communication has a lowest priority value of at least one priority value associated with the RB set, and wherein the subset of PSFCH communications omits at least one PSFCH communication of the set of PSFCH communications in association with the at least one PSFCH communication having a highest priority value of at least two priority values associated with an RB set of the second plurality of RB sets.

In a twelfth additional aspect, alone or in combination with one or more of the first through eleventh aspects, the subset of PSFCH communications omits at least one PSFCH communication of the set of PSFCH communications in association with the at least one PSFCH communication having a highest weighted priority value of at least two weighted priority values associated with the second plurality of RB sets.

In a thirteenth additional aspect, alone or in combination with one or more of the first through twelfth aspects, the at least one PSFCH communication has the highest weighted priority value based on the at least one PSFCH communication being associated with an outermost RB set of a third plurality of RB sets, wherein the third plurality of RB sets is selected from among the first plurality of RB sets using the group-based selection operation.

Although Figure 9 shows example blocks of process 900, in some aspects, process 900 may include additional blocks, fewer blocks, different blocks, or differently arranged blocks than those depicted in Figure 9. Additionally or alternatively, two or more of the blocks of process 900 may be performed in parallel.

Figure 10 is a flowchart illustrating an example process 1000 performed, for example, at a UE or an apparatus of a UE that supports simultaneous transmission of multiple PSFCH communications. Example process 1000 is an example where the apparatus or the UE (for example, UE 602) performs operations associated with PSFCH transmissions for non-contiguous resource block sets.

As shown in Figure 10, in some aspects, process 1000 may include monitoring at least one sidelink channel associated with an unlicensed spectrum for a plurality of sidelink communications (block 1010) . For example, the UE (such as by using communication manager 1108 or reception component 1102, depicted in Figure 11) may monitor at least one sidelink channel associated with an unlicensed spectrum for a plurality of sidelink communications, as described above.

As further shown in Figure 10, in some aspects, process 1000 may include transmitting, in a non-contiguous plurality of RB sets, a set PSFCH communications associated with the plurality of sidelink communications, wherein at least one RB set of the plurality of RB sets omits a PSFCH communication, and wherein transmitting the set of PSFCH communications comprises transmitting a common interlace in the at least one RB set, wherein the common interlace is associated with the set of PSFCH communications (block 1020) . For example, the UE (such as by using communication manager 1108 or transmission component 1104, depicted in Figure 11) may transmit, in a non-contiguous plurality of RB sets, a set of PSFCH communications associated with the plurality of sidelink communications, wherein at least one RB set of the plurality of RB sets omits a PSFCH communication, and wherein transmitting the set of PSFCH communications comprises transmitting a common interlace in the at least one RB set, wherein the common interlace is associated with the set of PSFCH communications, as described above.

Process 1000 may include additional aspects, such as any single aspect or any combination of aspects described below or in connection with one or more other processes described elsewhere herein.

In a first additional aspect, transmitting the common interlace in the at least one RB set comprises transmitting the common interlace in the at least one RB set in accordance with configuration information.

In a second additional aspect, alone or in combination with the first aspect, the configuration information is maintained in one or more memories of the UE.

In a third additional aspect, alone or in combination with one or more of the first and second aspects, process 1000 includes receiving a radio resource control message indicative of the configuration information.

Although Figure 10 shows example blocks of process 1000, in some aspects, process 1000 may include additional blocks, fewer blocks, different blocks, or differently arranged blocks than those depicted in Figure 10. Additionally or alternatively, two or more of the blocks of process 1000 may be performed in parallel.

Figure 11 is a diagram of an example apparatus 1100 for wireless communication that supports simultaneous transmission of PSFCH communications. The apparatus 1100 may be a UE, or a UE may include the apparatus 1100. In some aspects, the apparatus 1100 includes a reception component 1102, a transmission component 1104, and a communication manager 1108, which may be in communication with one another (for example, via one or more buses) . As shown, the apparatus 1100 may communicate with another apparatus 1106 (such as a UE, a network node, or another wireless communication device) using the reception component 1102 and the transmission component 1104.

In some aspects, the apparatus 1100 may be configured to and/or operable to perform one or more operations described herein in connection with Figures 6A-7C. Additionally or alternatively, the apparatus 1100 may be configured to and/or operable to perform one or more processes described herein, such as process 800 of Figure 8, process 900 of Figure 9, and/or process 1000 of Figure 10. In some aspects, the apparatus 1100 may include one or more components of the UE described above in connection with Figure 2.

The reception component 1102 may receive communications, such as reference signals, control information, and/or data communications, from the apparatus 1106. The reception component 1102 may provide received communications to one or more other components of the apparatus 1100, such as the communication manager 140. In some aspects, the reception component 1102 may perform signal processing on the received communications (such as filtering, amplification, demodulation, analog-to-digital conversion, demultiplexing, deinterleaving, de-mapping, equalization, interference cancellation, or decoding, among other examples) , and may provide the processed signals to the one or more other components. In some aspects, the reception component 1102 may include one or more antennas, one or more modems, one or more demodulators, one or more MIMO detectors, one or more receive processors, one or more controllers/processors, and/or one or more memories of the UE described above in connection with Figure 2.

The transmission component 1104 may transmit communications, such as reference signals, control information, and/or data communications, to the apparatus 1106. In some aspects, the communication manager 140 may generate communications and may transmit the generated communications to the transmission component 1104 for transmission to the apparatus 1106. In some aspects, the transmission component 1104 may perform signal processing on the generated communications (such as filtering, amplification, modulation, digital-to-analog conversion, multiplexing, interleaving, mapping, or encoding, among other examples) , and may transmit the processed signals to the apparatus 1106. In some aspects, the transmission component 1104 may include one or more antennas, one or more modems, one or more modulators, one or more transmit MIMO processors, one or more transmit processors, one or more controllers/processors, and/or one or more memories of the UE described above in connection with Figure 2. In some aspects, the transmission component 1104 may be co-located with the reception component 1102 in one or more transceivers.

The communication manager 1108 may monitor at least one sidelink channel associated with an unlicensed spectrum for a plurality of sidelink communications. The communication manager 1108 may transmit or may cause the transmission component 1104 to transmit a subset of PSFCH communications, of a set of PSFCH communications, using a second plurality of RB sets that are contiguous in a frequency domain, wherein the second plurality of RB sets is selected from among a first plurality of RB sets corresponding to the set of PSFCH communications, and wherein the first plurality of RB sets is selected using a PSFCH selection process. In some aspects, the communication manager 1108 may perform one or more operations described elsewhere herein as being performed by one or more components of the communication manager 140.

The communication manager 1108 may monitor at least one sidelink channel associated with an unlicensed spectrum for a plurality of sidelink communications. The communication manager 1108 may transmit or may cause the transmission component 1104 to transmit a subset of PSFCH communications, of a set of PSFCH communications, using a second plurality of RB sets selected, using a group-based selection operation, from among a first plurality of RB sets corresponding to the set of PSFCH communications associated with the plurality of sidelink communications. In some aspects, the communication manager 1108 may perform one or more operations described elsewhere herein as being performed by one or more components of the communication manager 140.

The communication manager 1108 may monitor at least one sidelink channel associated with an unlicensed spectrum for a plurality of sidelink communications. The communication manager 1108 may transmit or may cause the transmission component 1104 to transmit, in a non-contiguous plurality of RB sets, a set of PSFCH communications associated with the plurality of sidelink communications, wherein at least one RB set of the plurality of RB sets omits a PSFCH communication, and wherein transmitting the set of PSFCH communications comprises transmitting a common interlace in the at least one RB set, wherein the common interlace is associated with the set of PSFCH communications. In some aspects, the communication manager 1108 may perform one or more operations described elsewhere herein as being performed by one or more components of the communication manager 140.

The communication manager 1108 may include one or more controllers/processors, one or more memories of the UE described above in connection with Figure 2. In some aspects, the communication manager 140 includes a set of components. Alternatively, the set of components may be separate and distinct from the communication manager 140. In some aspects, one or more components of the set of components may include or may be implemented within one or more controllers/processors, one or more memories of the UE described above in connection with Figure 2. Additionally or alternatively, one or more components of the set of components may be implemented at least in part as software stored in one or more memories. For example, a component (or a portion of a component) may be implemented as instructions or code stored in a non-transitory computer-readable medium and executable by one or more controllers or one or more processors to perform the functions or operations of the component.

The reception component 1102 may monitor at least one sidelink channel associated with an unlicensed spectrum for a plurality of sidelink communications. The transmission component 1104 may transmit a subset of PSFCH communications, of a set of PSFCH communications, using a second plurality of RB sets that are contiguous in a frequency domain, wherein the second plurality of RB sets is selected from among a first plurality of RB sets corresponding to the set of PSFCH communications, and wherein the first plurality of RB sets is selected using a PSFCH selection process.

The reception component 1102 may monitor at least one sidelink channel associated with an unlicensed spectrum for a plurality of sidelink communications. The transmission component 1104 may transmit a subset of PSFCH communications, of a set of PSFCH communications, using a second plurality of RB sets selected, using a group-based selection operation, from among a first plurality of RB sets corresponding to the set of PSFCH communications associated with the plurality of sidelink communications.

The reception component 1102 may receive a radio resource control message indicative of the equivalent energy level.

The reception component 1102 may monitor at least one sidelink channel associated with an unlicensed spectrum for a plurality of sidelink communications. The transmission component 1104 may transmit, in a non-contiguous plurality of RB sets, a set of PSFCH communications associated with the plurality of sidelink communications, wherein at least one RB set of the plurality of RB sets omits a PSFCH communication, and wherein transmitting the set of PSFCH communications comprises transmitting a common interlace in the at least one RB set, wherein the common interlace is associated with the set of PSFCH communications.

The reception component 1102 may receive a radio resource control message indicative of the configuration information.

The number and arrangement of components shown in Figure 11 are provided as an example. In practice, there may be additional components, fewer components, different components, or differently arranged components than those shown in Figure 11. Furthermore, two or more components shown in Figure 11 may be implemented within a single component, or a single component shown in Figure 11 may be implemented as multiple, distributed components. Additionally or alternatively, a set of (one or more) components shown in Figure 11 may perform one or more functions described as being performed by another set of components shown in Figure 11.

The following provides an overview of some Aspects of the present disclosure:

Aspect 1: A method of wireless communication performed by a user equipment (UE) , comprising: monitoring at least one sidelink channel associated with an unlicensed spectrum for a plurality of sidelink communications; and transmitting a subset of physical sidelink feedback channel (PSFCH) communications, of a set of PSFCH communications, using a second plurality of resource block (RB) sets that are contiguous in a frequency domain, wherein the second plurality of RB sets is selected from among a first plurality of RB sets corresponding to the set of PSFCH communications, and wherein the first plurality of RB sets is selected using an initial PSFCH selection process.

Aspect 2: The method of Aspect 1, wherein the second plurality of RB sets is selected using an additional PSFCH selection process, wherein the additional PSFCH selection process comprises a continuation of the initial PSFCH selection process.

Aspect 3: The method of either of claims 1 or 2, wherein the second plurality of RB sets is selected using a set of weighted priority values, and wherein each weighted priority value of the set of weighted priority values is associated with a respective PSFCH communication of the set of PSFCH communications.

Aspect 4: The method of Aspect 3, wherein the second plurality of RB sets comprises a first RB set having a first weighted priority value of the set of weighted priority values, wherein the second plurality of RB sets omits a second RB set having a second weighted priority value of the set of weighted priority values, and wherein the second weighted priority value is higher than the first weighted priority value.

Aspect 5: The method of Aspect 4, wherein the first weighted priority value comprises an average priority value of two or more priority values corresponding, respectively, to two or more PSFCH communications, of the set of PSFCH communications, associated with the first RB set.

Aspect 6: The method of Aspect 4, wherein the first weighted priority value comprises a highest priority value of two or more priority values corresponding, respectively, to two or more PSFCH communications, of the set of PSFCH communications, associated with the first RB set.

Aspect 7: The method of Aspect 4, wherein the first weighted priority value comprises a lowest priority value of two or more priority values corresponding, respectively, to two or more PSFCH communications, of the set of PSFCH communications, associated with the first RB set.

Aspect 8: The method of Aspect 4, wherein the first weighted priority value comprises a function of two or more priority values corresponding, respectively, to two or more PSFCH communications, of the set of PSFCH communications and associated with the first RB set, wherein the function comprises a product of a second weighted priority value associated with the first RB set and a quantity of PSFCH communications associated with the first RB set.

Aspect 9: The method of any of Aspects 1-8, wherein the second plurality of RB sets is selected based on a selection of a first group of contiguous RB sets, of the first plurality of RB sets, using a set of weighted priority values, and wherein each weighted priority value of the set of weighted priority values is associated with a respective group of contiguous RB sets.

Aspect 10: The method of Aspect 9, wherein the second plurality of RB sets comprises the first group of contiguous RB sets, wherein the second plurality of RB sets omits a second group of contiguous RB sets set having a second weighted priority value of the set of weighted priority values, and wherein the second weighted priority value is higher than a first weighted priority value.

Aspect 11: The method of any of Aspects 9-10, wherein a first weighted priority value comprises a function of two or more priority values corresponding, respectively, to two or more RB sets of the first group of contiguous RB sets, wherein the function is associated with a quantity of PSFCH communications associated with the first group of contiguous RB sets.

Aspect 12: A method of wireless communication performed by a user equipment (UE) , comprising: monitoring at least one sidelink channel associated with an unlicensed spectrum for a plurality of sidelink communications; and transmitting a subset of physical sidelink feedback channel (PSFCH) communications, of a set of PSFCH communications, using a second plurality of resource block (RB) sets selected, using a group-based selection operation, from among a first plurality of RB sets corresponding to the set of PSFCH communications associated with the plurality of sidelink communications.

Aspect 13: The method of Aspect 12, wherein the second plurality of RB sets is selected based on a selection of a first group of contiguous RB sets, of the first plurality of RB sets, using a set of weighted priority values, and wherein each weighted priority value of the set of weighted priority values is associated with a respective group of contiguous RB sets.

Aspect 14: The method of Aspect 13, wherein the second plurality of RB sets comprises the first group of contiguous RB sets, wherein the second plurality of RB sets omits a second group of contiguous RB sets set having a second weighted priority value of the set of weighted priority values, and wherein the second weighted priority value is higher than a first weighted priority value.

Aspect 15: The method of either of Aspects 13 or 14, wherein the first group of contiguous RB sets comprises at least two RB sets, wherein each RB set of the at least two RB sets is associated with an equivalent channel occupancy time (COT) status.

Aspect 16: The method of any of Aspects 13-15, wherein the first group of contiguous RB sets comprises at least two RB sets, wherein each RB set of the at least two RB sets is associated with an equivalent energy level.

Aspect 17: The method of Aspect 16, wherein the equivalent energy level comprises a received signal strength indicator.

Aspect 18: The method of either of claims 16 or 17, wherein the equivalent energy level comprises a reference signal received power.

Aspect 19: The method of any of Aspects 16-18, wherein an indication of the equivalent energy level is maintained in one or more memories of the UE.

Aspect 20: The method of any of Aspects 16-19, further comprising receiving a radio resource control message indicative of the equivalent energy level.

Aspect 21: The method of any of Aspects 12-20, wherein the second plurality of RB sets is further based on a PSFCH dropping operation associated with a third plurality of RB sets, wherein the third plurality of RB sets is selected from among the first plurality of RB sets using the group-based selection operation.

Aspect 22: The method of any of Aspects 12-21, wherein the second plurality of RB sets omits at least one RB set of the third plurality of RB sets based on the at least one RB set comprising an outermost RB set of the third plurality of RB sets.

Aspect 23: The method of any of Aspects 12-22, wherein each RB set of the second plurality of RB sets comprises an initial PSFCH communication, wherein the initial PSFCH communication has a lowest priority value of at least one priority value associated with the RB set, and wherein the subset of PSFCH communications omits at least one PSFCH communication of the set of PSFCH communications in association with the at least one PSFCH communication having a highest priority value of at least two priority values associated with an RB set of the second plurality of RB sets.

Aspect 24: The method of any of Aspects 12-23, wherein the subset of PSFCH communications omits at least one PSFCH communication of the set of PSFCH communications in association with the at least one PSFCH communication having a highest weighted priority value of at least two weighted priority values associated with the second plurality of RB sets.

Aspect 25: The method of Aspect 24, wherein the at least one PSFCH communication has the highest weighted priority value based on the at least one PSFCH communication being associated with an outermost RB set of a third plurality of RB sets, wherein the third plurality of RB sets is selected from among the first plurality of RB sets using the group-based selection operation.

Aspect 26: A method of wireless communication performed by a user equipment (UE) , comprising: monitoring at least one sidelink channel associated with an unlicensed spectrum for a plurality of sidelink communications; and transmitting, in a non-contiguous plurality of resource block (RB) sets, a set of physical sidelink feedback channel (PSFCH) communications associated with the plurality of sidelink communications, wherein at least one RB set of the plurality of RB sets omits a PSFCH communication, and wherein transmitting the set of PSFCH communications comprises transmitting a common interlace in the at least one RB set, wherein the common interlace is associated with the set of PSFCH communications.

Aspect 27: The method of Aspect 26, wherein transmitting the common interlace in the at least one RB set comprises transmitting the common interlace in the at least one RB set in accordance with configuration information.

Aspect 28: The method of Aspect 27, wherein the configuration information is maintained in one or more memories of the UE.

Aspect 29: The method of either of Aspects 27 or 28, further comprising receiving a radio resource control message indicative of the configuration information.

Aspect 30: An apparatus for wireless communication at a device, the apparatus comprising one or more processors; one or more memories coupled with the one or more processors; and instructions stored in the one or more memories and executable by the one or more processors to cause the apparatus to perform the method of one or more of Aspects 1-11.

Aspect 31: An apparatus for wireless communication at a device, the apparatus comprising one or more memories and one or more processors coupled to the one or more memories, the one or more processors configured to cause the device to perform the method of one or more of Aspects 1-11.

Aspect 32: An apparatus for wireless communication, the apparatus comprising at least one means for performing the method of one or more of Aspects 1-11.

Aspect 33: A non-transitory computer-readable medium storing code for wireless communication, the code comprising instructions executable by one or more processors to perform the method of one or more of Aspects 1-11.

Aspect 34: A non-transitory computer-readable medium storing a set of instructions for wireless communication, the set of instructions comprising one or more instructions that, when executed by one or more processors of a device, cause the device to perform the method of one or more of Aspects 1-11.

Aspect 35: A device for wireless communication, the device comprising a processing system that includes one or more processors and one or more memories coupled with the one or more processors, the processing system configured to cause the device to perform the method of one or more of Aspects 1-11.

Aspect 36: An apparatus for wireless communication at a device, the apparatus comprising one or more memories and one or more processors coupled to the one or more memories, the one or more processors individually or collectively configured to cause the device to perform the method of one or more of Aspects 1-11.

Aspect 37: An apparatus for wireless communication at a device, the apparatus comprising one or more processors; one or more memories coupled with the one or more processors; and instructions stored in the one or more memories and executable by the one or more processors to cause the apparatus to perform the method of one or more of Aspects 12-25.

Aspect 38: An apparatus for wireless communication at a device, the apparatus comprising one or more memories and one or more processors coupled to the one or more memories, the one or more processors configured to cause the device to perform the method of one or more of Aspects 12-25.

Aspect 39: An apparatus for wireless communication, the apparatus comprising at least one means for performing the method of one or more of Aspects 12-25.

Aspect 40: A non-transitory computer-readable medium storing code for wireless communication, the code comprising instructions executable by one or more processors to perform the method of one or more of Aspects 12-25.

Aspect 41: A non-transitory computer-readable medium storing a set of instructions for wireless communication, the set of instructions comprising one or more instructions that, when executed by one or more processors of a device, cause the device to perform the method of one or more of Aspects 12-25.

Aspect 42: A device for wireless communication, the device comprising a processing system that includes one or more processors and one or more memories coupled with the one or more processors, the processing system configured to cause the device to perform the method of one or more of Aspects 12-25.

Aspect 43: An apparatus for wireless communication at a device, the apparatus comprising one or more memories and one or more processors coupled to the one or more memories, the one or more processors individually or collectively configured to cause the device to perform the method of one or more of Aspects 12-25.

Aspect 44: An apparatus for wireless communication at a device, the apparatus comprising one or more processors; one or more memories coupled with the one or more processors; and instructions stored in the one or more memories and executable by the one or more processors to cause the apparatus to perform the method of one or more of Aspects 26-29.

Aspect 45: An apparatus for wireless communication at a device, the apparatus comprising one or more memories and one or more processors coupled to the one or more memories, the one or more processors configured to cause the device to perform the method of one or more of Aspects 26-29.

Aspect 46: An apparatus for wireless communication, the apparatus comprising at least one means for performing the method of one or more of Aspects 26-29.

Aspect 47: A non-transitory computer-readable medium storing code for wireless communication, the code comprising instructions executable by one or more processors to perform the method of one or more of Aspects 26-29.

Aspect 48: A non-transitory computer-readable medium storing a set of instructions for wireless communication, the set of instructions comprising one or more instructions that, when executed by one or more processors of a device, cause the device to perform the method of one or more of Aspects 26-29.

Aspect 49: A device for wireless communication, the device comprising a processing system that includes one or more processors and one or more memories coupled with the one or more processors, the processing system configured to cause the device to perform the method of one or more of Aspects 26-29.

Aspect 50: An apparatus for wireless communication at a device, the apparatus comprising one or more memories and one or more processors coupled to the one or more memories, the one or more processors individually or collectively configured to cause the device to perform the method of one or more of Aspects 26-29.

The foregoing disclosure provides illustration and description but is not intended to be exhaustive or to limit the aspects to the precise forms disclosed. Modifications and variations may be made in light of the above disclosure or may be acquired from practice of the aspects.

As used herein, the term “component” is intended to be broadly construed as hardware or a combination of hardware and software. “Software” shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, or functions, among other examples, whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. As used herein, a “processor” is implemented in hardware or a combination of hardware and software. It will be apparent that systems or methods described herein may be implemented in different forms of hardware or a combination of hardware and software. The actual specialized control hardware or software code used to implement these systems or methods is not limiting of the aspects. Thus, the operation and behavior of the systems or methods are described herein without reference to specific software code, because those skilled in the art will understand that software and hardware can be designed to implement the systems or methods based, at least in part, on the description herein.

As used herein, “satisfying a threshold” may, depending on the context, refer to a value being greater than the threshold, greater than or equal to the threshold, less than the threshold, less than or equal to the threshold, equal to the threshold, or not equal to the threshold, among other examples.

As used herein, the term “determine” or “determining” encompasses a wide variety of actions and, therefore, “determining” can include calculating, computing, processing, deriving, investigating, looking up (such as via looking up in a table, a database or another data structure) , identifying, inferring, ascertaining, measuring, and the like. Also, “determining” can include receiving (such as receiving information or receiving an indication) , accessing (such as accessing data stored in memory) , transmitting (such as transmitting information) and the like. Also, “determining” can include resolving, selecting, obtaining, choosing, establishing and other such similar actions. The term “identify” or “identifying” also encompasses a wide variety of actions and, therefore, “identifying” can include calculating, computing, processing, deriving, investigating, looking up (such as via looking up in a table, a database or another data structure) , inferring, ascertaining, measuring, and the like. Also, “identifying” can include receiving (such as receiving information or receiving an indication) , accessing (such as accessing data stored in memory) , transmitting (such as transmitting information) and the like. Also, “identifying” can include resolving, selecting, obtaining, choosing, establishing and other such similar actions.

Even though particular combinations of features are recited in the claims or disclosed in the specification, these combinations are not intended to limit the disclosure of various aspects. Many of these features may be combined in ways not specifically recited in the claims or disclosed in the specification. The disclosure of various aspects includes each dependent claim in combination with every other claim in the claim set. As used herein, a phrase referring to “at least one of” a list of items refers to any combination of those items, including single members. As an example, “at least one of: a, b, or c” is intended to cover a, b, c, a + b, a + c, b + c, and a + b + c, as well as any combination with multiples of the same element (for example, a + a, a + a + a, a + a + b, a + a + c, a +b + b, a + c + c, b + b, b + b + b, b + b + c, c + c, and c + c + c, or any other ordering of a, b, and c) .

No element, act, or instruction used herein should be construed as critical or essential unless explicitly described as such. Also, as used herein, the articles “a” and “an” are intended to include one or more items and may be used interchangeably with “one or more. ” Further, as used herein, the article “the” is intended to include one or more items referenced in connection with the article “the” and may be used interchangeably with “the one or more. ” Furthermore, as used herein, the terms “set” and “group” are intended to include one or more items and may be used interchangeably with “one or more. ” Where only one item is intended, the phrase “only one” or similar language is used. Also, as used herein, the terms “has, ” “have, ” “having, ” and similar terms are intended to be open-ended terms that do not limit an element that they modify (for example, an element “having” A may also have B) . Further, as used herein, “based on”is intended to be interpreted in the inclusive sense, unless otherwise explicitly indicated. For example, “based on” may be used interchangeably with “based at least in part on, ” “associated with” , or “in accordance with” unless otherwise explicitly indicated. Specifically, unless a phrase refers to “based on only ‘a, ’ ” or the equivalent in context, whatever it is that is “based on ‘a, ’ ” or “based at least in part on ‘a, ’ ” may be based on “a” alone or based on a combination of “a” and one or more other factors, conditions or information.. Also, as used herein, the term “or” is intended to be inclusive when used in a series and may be used interchangeably with “and/or, ” unless explicitly stated otherwise (for example, if used in combination with “either” or “only one of” ) .

Claims

An apparatus for wireless communication at a user equipment (UE) , comprising:

one or more memories storing processor-executable code; and

one or more processors coupled with the one or more memories, at least one processor of the one or more processors configured to cause the UE to:

monitor at least one sidelink channel associated with an unlicensed spectrum for a plurality of sidelink communications; and

transmit a subset of physical sidelink feedback channel (PSFCH) communications, of a set of PSFCH communications, using a second plurality of resource block (RB) sets that are contiguous in a frequency domain, wherein the second plurality of RB sets is selected from among a first plurality of RB sets corresponding to the set of PSFCH communications, and wherein the first plurality of RB sets is selected using an initial PSFCH selection process.
The apparatus of claim 1, wherein the second plurality of RB sets is selected using an additional PSFCH selection process, wherein the additional PSFCH selection process comprises a continuation of the initial PSFCH selection process.
The apparatus of claim 1, wherein the second plurality of RB sets is selected using a set of weighted priority values, and wherein each weighted priority value of the set of weighted priority values is associated with a respective PSFCH communication of the set of PSFCH communications.
The apparatus of claim 3, wherein the second plurality of RB sets comprises a first RB set having a first weighted priority value of the set of weighted priority values, wherein the second plurality of RB sets omits a second RB set having a second weighted priority value of the set of weighted priority values, and wherein the second weighted priority value is higher than the first weighted priority value.
The apparatus of claim 4, wherein the first weighted priority value comprises an average priority value of two or more priority values corresponding, respectively, to two or more PSFCH communications, of the set of PSFCH communications, associated with the first RB set.
The apparatus of claim 4, wherein the first weighted priority value comprises a highest priority value of two or more priority values corresponding, respectively, to two or more PSFCH communications, of the set of PSFCH communications, associated with the first RB set.
The apparatus of claim 4, wherein the first weighted priority value comprises a lowest priority value of two or more priority values corresponding, respectively, to two or more PSFCH communications, of the set of PSFCH communications, associated with the first RB set.
The apparatus of claim 4, wherein the first weighted priority value comprises a function of two or more priority values corresponding, respectively, to two or more PSFCH communications, of the set of PSFCH communications and associated with the first RB set, wherein the function comprises a product of a second weighted priority value associated with the first RB set and a quantity of PSFCH communications associated with the first RB set.
The apparatus of claim 2, wherein the second plurality of RB sets is selected based on a selection of a first group of contiguous RB sets, of the first plurality of RB sets, using a set of weighted priority values, and wherein each weighted priority value of the set of weighted priority values is associated with a respective group of contiguous RB sets.
The apparatus of claim 9, wherein the second plurality of RB sets comprises the first group of contiguous RB sets, wherein the second plurality of RB sets omits a second group of contiguous RB sets set having a second weighted priority value of the set of weighted priority values, and wherein the second weighted priority value is higher than a first weighted priority value.
The apparatus of claim 9, wherein a first weighted priority value comprises a function of two or more priority values corresponding, respectively, to two or more RB sets of the first group of contiguous RB sets, wherein the function is associated with a quantity of PSFCH communications associated with the first group of contiguous RB sets.
An apparatus for wireless communication at a user equipment (UE) , comprising:

one or more memories storing processor-executable code; and

one or more processors coupled with the one or more memories, at least one processor of the one or more processors configured to cause the UE to:

monitor at least one sidelink channel associated with an unlicensed spectrum for a plurality of sidelink communications; and

transmit a subset of physical sidelink feedback channel (PSFCH) communications, of a set of PSFCH communications, using a second plurality of resource block (RB) sets selected, using a group-based selection operation, from among a first plurality of RB sets corresponding to the set of PSFCH communications associated with the plurality of sidelink communications.
The apparatus of claim 12, wherein the second plurality of RB sets is selected based on a selection of a first group of contiguous RB sets, of the first plurality of RB sets, using a set of weighted priority values, and wherein each weighted priority value of the set of weighted priority values is associated with a respective group of contiguous RB sets.
The apparatus of claim 13, wherein the second plurality of RB sets comprises the first group of contiguous RB sets, wherein the second plurality of RB sets omits a second group of contiguous RB sets set having a second weighted priority value of the set of weighted priority values, and wherein the second weighted priority value is higher than a first weighted priority value.
The apparatus of claim 13, wherein the first group of contiguous RB sets comprises at least two RB sets, wherein each RB set of the at least two RB sets is associated with at least one of an equivalent channel occupancy time (COT) status or an equivalent energy level.
The apparatus of claim 15, wherein the equivalent energy level comprises at least one of a received signal strength indicator or a reference signal received power.
The apparatus of claim 15, wherein an indication of the equivalent energy level is maintained in one or more memories of the UE.
The apparatus of claim 15, wherein the at least one processor of the one or more processors is further configured to cause the UE to receive a radio resource control message indicative of the equivalent energy level.
The apparatus of claim 12, wherein the second plurality of RB sets is further based on a PSFCH dropping operation associated with a third plurality of RB sets, wherein the third plurality of RB sets is selected from among the first plurality of RB sets using the group-based selection operation.
The apparatus of claim 19, wherein the second plurality of RB sets omits at least one RB set of the third plurality of RB sets based on the at least one RB set comprising an outermost RB set of the third plurality of RB sets.
The apparatus of claim 12, wherein each RB set of the second plurality of RB sets comprises an initial PSFCH communication, wherein the initial PSFCH communication has a lowest priority value of at least one priority value associated with the RB set, and wherein the subset of PSFCH communications omits at least one PSFCH communication of the set of PSFCH communications in association with the at least one PSFCH communication having a highest priority value of at least two priority values associated with an RB set of the second plurality of RB sets.
The apparatus of claim 12, wherein the subset of PSFCH communications omits at least one PSFCH communication of the set of PSFCH communications in association with the at least one PSFCH communication having a highest weighted priority value of at least two weighted priority values associated with the second plurality of RB sets.
The apparatus of claim 22, wherein the at least one PSFCH communication has the highest weighted priority value based on the at least one PSFCH communication being associated with an outermost RB set of a third plurality of RB sets, wherein the third plurality of RB sets is selected from among the first plurality of RB sets using the group-based selection operation.
An apparatus for wireless communication at a user equipment (UE) , comprising:

one or more memories storing processor-executable code; and

one or more processors coupled with the one or more memories, at least one processor of the one or more processors configured to cause the UE to:

monitor at least one sidelink channel associated with an unlicensed spectrum for a plurality of sidelink communications; and

transmit, in a non-contiguous plurality of resource block (RB) sets, a set of physical sidelink feedback channel (PSFCH) communications associated with the plurality of sidelink communications, wherein at least one RB set of the plurality of RB sets omits a PSFCH communication, and wherein transmitting the set of PSFCH communications comprises transmitting a common interlace in the at least one RB set, wherein the common interlace is associated with the set of PSFCH communications.
The apparatus of claim 24, wherein the at least one processor, of the one or more processors, to cause the UE to transmit the common interlace in the at least one RB set, is configured to cause the UE to transmit the common interlace in the at least one RB set in accordance with configuration information.
The apparatus of claim 25, wherein the configuration information is maintained in one or more memories of the UE.
The apparatus of claim 25, wherein the at least one processor of the one or more processors is further configured to cause the UE to receive a radio resource control message indicative of the configuration information.
A method of wireless communication performed by a user equipment (UE) , comprising:

monitoring at least one sidelink channel associated with an unlicensed spectrum for a plurality of sidelink communications; and

transmitting a subset of physical sidelink feedback channel (PSFCH) communications, of a set of PSFCH communications, using a second plurality of resource block (RB) sets that are contiguous in a frequency domain, wherein the second plurality of RB sets is selected from among a first plurality of RB sets corresponding to the set of PSFCH communications, and wherein the first plurality of RB sets is selected using an initial PSFCH selection process.
The method of claim 28, wherein the second plurality of RB sets is selected using an additional PSFCH selection process, wherein the additional PSFCH selection process comprises a continuation of the initial PSFCH selection process.
The method of claim 28, wherein the second plurality of RB sets is selected using a set of weighted priority values, and wherein each weighted priority value of the set of weighted priority values is associated with a respective PSFCH communication of the set of PSFCH communications.