Patent Publication Number: US-2023133718-A1

Title: Sidelink feedback resources

Description:
FIELD OF THE DISCLOSURE 
     Aspects of the present disclosure generally relate to wireless communication and to techniques and apparatuses for configuring and using sidelink feedback resources. 
     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 (e.g., bandwidth, transmit power, or the like). 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). 
     A wireless network may include one or more base stations that support communication for a user equipment (UE) or multiple UEs. A UE may communicate with a base station via downlink communications and uplink communications. “Downlink” (or “DL”) refers to a communication link from the base station to the UE, and “uplink” (or “UL”) refers to a communication link from the UE to the base station. 
     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, and/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 and/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. 
    
    
     
       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 certain 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. 
         FIG.  1    is a diagram illustrating an example of a wireless network, in accordance with the present disclosure. 
         FIG.  2    is a diagram illustrating an example of a base station in communication with a user equipment (UE) in a wireless network, in accordance with the present disclosure. 
         FIG.  3    is a diagram illustrating an example of resource pools for sidelink communications, in accordance with the present disclosure. 
         FIG.  4    is a diagram illustrating an example of resources for sidelink feedback, in accordance with the present disclosure. 
         FIG.  5    is a diagram illustrating an example associated with resources for long-range sidelink feedback, in accordance with the present disclosure. 
         FIG.  6    is a diagram illustrating an example associated with triggers for long-range sidelink feedback, in accordance with the present disclosure. 
         FIG.  7    is a diagram illustrating an example associated with timing advances for long-range sidelink feedback, in accordance with the present disclosure. 
         FIG.  8    is a diagram illustrating an example associated with configuration of long-range sidelink feedback between mobile stations, in accordance with the present disclosure. 
         FIGS.  9 A and  9 B  are diagrams illustrating examples associated with demodulation reference signal (DMRS) density and staggering, in accordance with the present disclosure. 
         FIG.  10    is a diagram illustrating an example associated with DMRS hopping across symbols, in accordance with the present disclosure. 
         FIG.  11    is a diagram illustrating an example associated with configuration of DMRSs between mobile stations, in accordance with the present disclosure. 
         FIGS.  12 ,  13 ,  14 , and  15    are diagrams illustrating example processes associated with configuring and using sidelink feedback resources, in accordance with the present disclosure. 
         FIGS.  16 ,  17 ,  18 , and  19    are diagrams illustrating example processes associated with configuration of DMRSs between mobile stations, in accordance with the present disclosure. 
         FIG.  20    is a diagram of an example apparatus for wireless communication, in accordance with the present disclosure. 
     
    
    
     SUMMARY 
     Some aspects described herein relate to a method of wireless communication performed by a mobile station. The method may include receiving an indication of a first set of resources for feedback and an indication of a second set of resources for feedback, wherein the second set of resources are associated with a smaller quantity of cyclic shifts than the first set of resources. The method may include transmitting feedback on either the first set of resources or the second set of resources based at least in part on a distance associated with the feedback. 
     Some aspects described herein relate to a method of wireless communication performed by a mobile station. The method may include determining a first set of resources for feedback and a second set of resources for feedback, wherein the second set of resources are associated with a smaller quantity of cyclic shifts than the first set of resources. The method may include transmitting an indication of the first set of resources and an indication of the second set of resources. 
     Some aspects described herein relate to a method of wireless communication performed by a mobile station. The method may include computing a timing advance associated with transmission of feedback. The method may include transmitting feedback that is shifted in time according to the timing advance. 
     Some aspects described herein relate to a method of wireless communication performed by a transmitting mobile station. The method may include transmitting information associated with at least one distance threshold, to a receiving mobile station, for long-range sidelink feedback. The method may include transmitting an indication associated with a plurality of sets of minimum communication ranges (MCRs) to the receiving mobile station. 
     Some aspects described herein relate to a method of wireless communication performed by a mobile station. The method may include receiving an indication of a first set of resources and an indication of a second set of resources, wherein the second set of resources are associated with a smaller quantity of cyclic shifts in demodulation reference signals (DMRSs) than the first set of resources. The method may include transmitting DMRSs on either the first set of resources or the second set of resources based at least in part on a distance associated with the DMRSs. 
     Some aspects described herein relate to a method of wireless communication performed by a mobile station. The method may include determining a first set of resources and a second set of resources, wherein the second set of resources are associated with a smaller quantity of cyclic shifts in DMRSs than the first set of resources. The method may include transmitting an indication of the first set of resources and an indication of the second set of resources. 
     Some aspects described herein relate to a method of wireless communication performed by a mobile station. The method may include receiving a configuration associated with DMRSs on a sidelink channel. The method may include transmitting DMRSs that are staggered across symbols, include cyclic shift hopping across symbols, are denser than one DMRS per four resource elements (REs), or a combination thereof. 
     Some aspects described herein relate to a method of wireless communication performed by a mobile station. The method may include determining a configuration associated with DMRSs on a sidelink channel, wherein the configuration is associated with DMRSs that are staggered across symbols, include cyclic shift hopping across symbols, are denser than one DMRS per four REs, or a combination thereof. The method may include transmitting the configuration. 
     Some aspects described herein relate to an apparatus for wireless communication at a mobile station. The apparatus may include a memory and one or more processors coupled to the memory. The one or more processors may be configured to receive an indication of a first set of resources for feedback and an indication of a second set of resources for feedback, wherein the second set of resources are associated with a smaller quantity of cyclic shifts than the first set of resources. The one or more processors may be configured to transmit feedback on either the first set of resources or the second set of resources based at least in part on a distance associated with the feedback. 
     Some aspects described herein relate to an apparatus for wireless communication at a mobile station. The apparatus may include a memory and one or more processors coupled to the memory. The one or more processors may be configured to determine a first set of resources for feedback and a second set of resources for feedback, wherein the second set of resources are associated with a smaller quantity of cyclic shifts than the first set of resources. The one or more processors may be configured to transmit an indication of the first set of resources and an indication of the second set of resources. 
     Some aspects described herein relate to an apparatus for wireless communication at a mobile station. The apparatus may include a memory and one or more processors coupled to the memory. The one or more processors may be configured to compute a timing advance associated with transmission of feedback. The one or more processors may be configured to transmit feedback that is shifted in time according to the timing advance. 
     Some aspects described herein relate to an apparatus for wireless communication at a transmitting mobile station. The apparatus may include a memory and one or more processors coupled to the memory. The one or more processors may be configured to transmit information associated with at least one distance threshold, to a receiving mobile station, for long-range sidelink feedback. The one or more processors may be configured to transmit an indication associated with a plurality of sets of MCRs to the mobile station. 
     Some aspects described herein relate to an apparatus for wireless communication at a mobile station. The apparatus may include a memory and one or more processors coupled to the memory. The one or more processors may be configured to receive an indication of a first set of resources and an indication of a second set of resources, wherein the second set of resources are associated with a smaller quantity of cyclic shifts in DMRSs than the first set of resources. The one or more processors may be configured to transmit DMRSs on either the first set of resources or the second set of resources based at least in part on a distance associated with the DMRSs. 
     Some aspects described herein relate to an apparatus for wireless communication at a mobile station. The apparatus may include a memory and one or more processors coupled to the memory. The one or more processors may be configured to determine a first set of resources and a second set of resources, wherein the second set of resources are associated with a smaller quantity of cyclic shifts in DMRSs than the first set of resources. The one or more processors may be configured to transmit an indication of the first set of resources and an indication of the second set of resources. 
     Some aspects described herein relate to an apparatus for wireless communication at a mobile station. The apparatus may include a memory and one or more processors coupled to the memory. The one or more processors may be configured to receive a configuration associated with DMRSs on a sidelink channel. The one or more processors may be configured to transmit DMRSs that are staggered across symbols, include cyclic shift hopping across symbols, are denser than one DMRS per four REs, or a combination thereof. 
     Some aspects described herein relate to an apparatus for wireless communication at a mobile station. The apparatus may include a memory and one or more processors coupled to the memory. The one or more processors may be configured to determine a configuration associated with DMRSs on a sidelink channel, wherein the configuration is associated with DMRSs that are staggered across symbols, include cyclic shift hopping across symbols, are denser than one DMRS per four REs, or a combination thereof. The one or more processors may be configured to transmit the configuration. 
     Some aspects described herein relate to a non-transitory computer-readable medium that stores a set of instructions for wireless communication by a mobile station. The set of instructions, when executed by one or more processors of the mobile station, may cause the mobile station to receive an indication of a first set of resources for feedback and an indication of a second set of resources for feedback, wherein the second set of resources are associated with a smaller quantity of cyclic shifts than the first set of resources. The set of instructions, when executed by one or more processors of the mobile station, may further cause the mobile station to transmit feedback on either the first set of resources or the second set of resources based at least in part on a distance associated with the feedback. 
     Some aspects described herein relate to a non-transitory computer-readable medium that stores a set of instructions for wireless communication by a mobile station. The set of instructions, when executed by one or more processors of the mobile station, may cause the mobile station to determine a first set of resources for feedback and a second set of resources for feedback, wherein the second set of resources are associated with a smaller quantity of cyclic shifts than the first set of resources. The set of instructions, when executed by one or more processors of the mobile station, may further cause the mobile station to transmit an indication of the first set of resources and an indication of the second set of resources. 
     Some aspects described herein relate to a non-transitory computer-readable medium that stores a set of instructions for wireless communication by a mobile station. The set of instructions, when executed by one or more processors of the mobile station, may cause the mobile station to compute a timing advance associated with transmission of feedback. The set of instructions, when executed by one or more processors of the mobile station, may further cause the mobile station to transmit feedback that is shifted in time according to the timing advance. 
     Some aspects described herein relate to a non-transitory computer-readable medium that stores a set of instructions for wireless communication by a transmitting mobile station. The set of instructions, when executed by one or more processors of the mobile station, may cause the mobile station to transmit information associated with at least one distance threshold, to a receiving mobile station, for long-range sidelink feedback. The set of instructions, when executed by one or more processors of the mobile station, may further cause the mobile station to transmit an indication associated with a plurality of sets of MCRs to the mobile station. 
     Some aspects described herein relate to a non-transitory computer-readable medium that stores a set of instructions for wireless communication by a transmitting mobile station. The set of instructions, when executed by one or more processors of the mobile station, may cause the mobile station to receive an indication of a first set of resources and an indication of a second set of resources, wherein the second set of resources are associated with a smaller quantity of cyclic shifts in DMRSs than the first set of resources. The set of instructions, when executed by one or more processors of the mobile station, may further cause the mobile station to transmit DMRSs on either the first set of resources or the second set of resources based at least in part on a distance associated with the DMRSs. 
     Some aspects described herein relate to a non-transitory computer-readable medium that stores a set of instructions for wireless communication by a mobile station. The set of instructions, when executed by one or more processors of the mobile station, may cause the mobile station to determine a first set of resources and a second set of resources, wherein the second set of resources are associated with a smaller quantity of cyclic shifts in DMRSs than the first set of resources. The set of instructions, when executed by one or more processors of the mobile station, may further cause the mobile station to transmit an indication of the first set of resources and an indication of the second set of resources. 
     Some aspects described herein relate to a non-transitory computer-readable medium that stores a set of instructions for wireless communication by a mobile station. The set of instructions, when executed by one or more processors of the mobile station, may cause the mobile station to receive a configuration associated with DMRSs on a sidelink channel. The set of instructions, when executed by one or more processors of the mobile station, may further cause the mobile station to transmit DMRSs that are staggered across symbols, include cyclic shift hopping across symbols, are denser than one DMRS per four REs, or a combination thereof. 
     Some aspects described herein relate to a non-transitory computer-readable medium that stores a set of instructions for wireless communication by a mobile station. The set of instructions, when executed by one or more processors of the mobile station, may cause the mobile station to determine a configuration associated with DMRSs on a sidelink channel, wherein the configuration is associated with DMRSs that are staggered across symbols, include cyclic shift hopping across symbols, are denser than one DMRS per four REs, or a combination thereof. The set of instructions, when executed by one or more processors of the mobile station, may further cause the mobile station to transmit the configuration. 
     Some aspects described herein relate to an apparatus for wireless communication. The apparatus may include means for receiving an indication of a first set of resources for feedback and an indication of a second set of resources for feedback, wherein the second set of resources are associated with a smaller quantity of cyclic shifts than the first set of resources. The apparatus may include means for transmitting feedback on either the first set of resources or the second set of resources based at least in part on a distance associated with the feedback. 
     Some aspects described herein relate to an apparatus for wireless communication. The apparatus may include means for determining a first set of resources for feedback and a second set of resources for feedback, wherein the second set of resources are associated with a smaller quantity of cyclic shifts than the first set of resources. The apparatus may include means for transmitting an indication of the first set of resources and an indication of the second set of resources. 
     Some aspects described herein relate to an apparatus for wireless communication. The apparatus may include means for computing a timing advance associated with transmission of feedback. The apparatus may include means for transmitting feedback that is shifted in time according to the timing advance. 
     Some aspects described herein relate to an apparatus for wireless communication. The apparatus may include means for transmitting information associated with at least one distance threshold, to a receiving mobile station, for long-range sidelink feedback. The apparatus may include means for transmitting an indication associated with a plurality of sets of MCRs to the mobile station. 
     Some aspects described herein relate to an apparatus for wireless communication. The apparatus may include means for receiving an indication of a first set of resources and an indication of a second set of resources, wherein the second set of resources are associated with a smaller quantity of cyclic shifts in DMRSs than the first set of resources. The apparatus may include means for transmitting DMRSs on either the first set of resources or the second set of resources based at least in part on a distance associated with the DMRSs. 
     Some aspects described herein relate to an apparatus for wireless communication. The apparatus may include means for determining a first set of resources and a second set of resources, wherein the second set of resources are associated with a smaller quantity of cyclic shifts in DMRSs than the first set of resources. The apparatus may include means for transmitting an indication of the first set of resources and an indication of the second set of resources. 
     Some aspects described herein relate to an apparatus for wireless communication. The apparatus may include means for receiving a configuration associated with DMRSs on a sidelink channel. The apparatus may include means for transmitting DMRSs that are staggered across symbols, include cyclic shift hopping across symbols, are denser than one DMRS per four REs, or a combination thereof. 
     Some aspects described herein relate to an apparatus for wireless communication. The apparatus may include means for determining a configuration associated with DMRSs on a sidelink channel, wherein the configuration is associated with DMRSs that are staggered across symbols, include cyclic shift hopping across symbols, are denser than one DMRS per four REs, or a combination thereof. The apparatus may include means for transmitting the configuration. 
     Aspects generally include a method, apparatus, system, computer program product, non-transitory computer-readable medium, user equipment, base station, wireless communication device, and/or processing system as substantially described herein with reference to and as illustrated by the drawings and specification. 
     The foregoing has outlined rather broadly the features and technical advantages of examples according to 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. 
     While aspects are described in the present disclosure by illustration to some examples, those skilled in the art will understand that such aspects may be implemented in many different arrangements and scenarios. Techniques described herein may be implemented using different platform types, devices, systems, shapes, sizes, and/or packaging arrangements. For example, some aspects may be implemented via integrated chip embodiments or other non-module-component based devices (e.g., end-user devices, vehicles, communication devices, computing devices, industrial equipment, retail/purchasing devices, medical devices, and/or artificial intelligence devices). Aspects may be implemented in chip-level components, modular components, non-modular components, non-chip-level components, device-level components, and/or system-level components. Devices incorporating described aspects and features may include additional components and features for implementation and practice of claimed and described aspects. For example, transmission and reception of wireless signals may include one or more components for analog and digital purposes (e.g., hardware components including antennas, radio frequency (RF) chains, power amplifiers, modulators, buffers, processors, interleavers, adders, and/or summers). It is intended that aspects described herein may be practiced in a wide variety of devices, components, systems, distributed arrangements, and/or end-user devices of varying size, shape, and constitution. 
    
    
     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 should not 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 should 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 number 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. It should be understood that 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, algorithms, or the like (collectively referred to as “elements”). These elements may be implemented using hardware, software, or combinations thereof. Whether such elements are implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. 
     While aspects may be described herein using terminology commonly associated with a 5G or New Radio (NR) radio access technology (RAT), aspects of the present disclosure can be applied to other RATs, such as a 3G RAT, a 4G RAT, and/or a RAT subsequent to 5G (e.g., 6G). 
       FIG.  1    is a diagram illustrating an example of a wireless network  100 , in accordance with the present disclosure. The wireless network  100  may be or may include elements of a 5G (e.g., NR) network and/or a 4G (e.g., Long Term Evolution (LTE)) network, among other examples. The wireless network  100  may include one or more base stations  110  (shown as a BS  110   a , a BS  110   b , a BS  110   c , and a BS  110   d ), a user equipment (UE)  120  or multiple UEs  120  (shown as a UE  120   a , a UE  120   b , a UE  120   c , a UE  120   d , and a UE  120   e ), and/or other network entities. A base station  110  is an entity that communicates with UEs  120 . A base station  110  (sometimes referred to as a BS) may include, for example, an NR base station, an LTE base station, a Node B, an eNB (e.g., in 4G), a gNB (e.g., in 5G), an access point, and/or a transmission reception point (TRP). Each base station  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 base station  110  and/or a base station subsystem serving this coverage area, depending on the context in which the term is used. 
     A base station  110  may provide communication coverage for a macro cell, a pico cell, a femto cell, and/or another type of cell. A macro cell may cover a relatively large geographic area (e.g., 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 (e.g., a home) and may allow restricted access by UEs  120  having association with the femto cell (e.g., UEs  120  in a closed subscriber group (CSG)). A base station  110  for a macro cell may be referred to as a macro base station. A base station  110  for a pico cell may be referred to as a pico base station. A base station  110  for a femto cell may be referred to as a femto base station or an in-home base station. In the example shown in  FIG.  1   , the BS  110   a  may be a macro base station for a macro cell  102   a , the BS  110   b  may be a pico base station for a pico cell  102   b , and the BS  110   c  may be a femto base station for a femto cell  102   c . A base station may support one or multiple (e.g., three) cells. 
     In some examples, a cell may not necessarily be stationary, and the geographic area of the cell may move according to the location of a base station  110  that is mobile (e.g., a mobile base station). In some examples, the base stations  110  may be interconnected to one another and/or to one or more other base stations  110  or network nodes (not shown) in the wireless network  100  through various types of backhaul interfaces, such as a direct physical connection or a virtual network, using any suitable transport network. 
     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 (e.g., a base station  110  or a UE  120 ) and send a transmission of the data to a downstream station (e.g., a UE  120  or a base station  110 ). A relay station may be a UE  120  that can relay transmissions for other UEs  120 . In the example shown in  FIG.  1   , the BS  110   d  (e.g., a relay base station) may communicate with the BS  110   a  (e.g., a macro base station) and the UE  120   d  in order to facilitate communication between the BS  110   a  and the UE  120   d . A base station  110  that relays communications may be referred to as a relay station, a relay base station, a relay, or the like. 
     The wireless network  100  may be a heterogeneous network that includes base stations  110  of different types, such as macro base stations, pico base stations, femto base stations, relay base stations, or the like. These different types of base stations  110  may have different transmit power levels, different coverage areas, and/or different impacts on interference in the wireless network  100 . For example, macro base stations may have a high transmit power level (e.g., 5 to 40 watts) whereas pico base stations, femto base stations, and relay base stations may have lower transmit power levels (e.g., 0.1 to 2 watts). 
     A network controller  130  may couple to or communicate with a set of base stations  110  and may provide coordination and control for these base stations  110 . The network controller  130  may communicate with the base stations  110  via a backhaul communication link. The base stations  110  may communicate with one another directly or indirectly via a wireless or wireline backhaul communication link. 
     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, and/or a subscriber unit. A UE  120  may be a cellular phone (e.g., 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 (e.g., a smart watch, smart clothing, smart glasses, a smart wristband, smart jewelry (e.g., a smart ring or a smart bracelet)), an entertainment device (e.g., a music device, a video device, and/or a satellite radio), a vehicular component or sensor, a smart meter/sensor, industrial manufacturing equipment, a global positioning system device, and/or any other suitable device that is configured to communicate via a wireless medium. 
     Some UEs  120  may be considered machine-type communication (MTC) or evolved or enhanced machine-type communication (eMTC) UEs. An MTC UE and/or an eMTC UE may include, for example, a robot, a drone, a remote device, a sensor, a meter, a monitor, and/or a location tag, that may communicate with a base station, another device (e.g., a remote device), or some other entity. Some UEs  120  may be considered Internet-of-Things (IoT) devices, and/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 and/or memory components. In some examples, the processor components and the memory components may be coupled together. For example, the processor components (e.g., one or more processors) and the memory components (e.g., a memory) may be operatively coupled, communicatively coupled, electronically coupled, and/or electrically coupled. 
     In general, any number of wireless networks  100  may be deployed in a given geographic area. Each wireless network  100  may support a particular RAT and may operate on one or more frequencies. A RAT may be referred to as a radio technology, an air interface, or the like. A frequency may be referred to as a carrier, a frequency channel, or the like. Each frequency may support a single RAT in a given geographic area in order to avoid interference between wireless networks of different RATs. In some cases, NR or 5G RAT networks may be deployed. 
     In some examples, two or more UEs  120  (e.g., shown as UE  120   a  and UE  120   e ) may communicate directly using one or more sidelink channels (e.g., without using a base station  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 (e.g., which may include a vehicle-to-vehicle (V2V) protocol, a vehicle-to-infrastructure (V2I) protocol, or a vehicle-to-pedestrian (V2P) protocol), and/or a mesh network. In such examples, a UE  120  may perform scheduling operations, resource selection operations, and/or other operations described elsewhere herein as being performed by the base station  110 . 
     Devices of the wireless network  100  may communicate using the electromagnetic spectrum, which may be subdivided by frequency or wavelength into various classes, bands, channels, or the like. For example, devices of the wireless network  100  may communicate using one or more operating bands. In 5GNR, two initial operating bands have been identified as frequency range designations FR 1  (410 MHz - 7.125 GHz) and FR 2  (24.25 GHz - 52.6 GHz). It should be understood that although a portion of FR 1  is greater than 6 GHz, FR 1  is often referred to (interchangeably) as a “Sub-6 GHz” band in various documents and articles. A similar nomenclature issue sometimes occurs with regard to FR 2 , which is often referred to (interchangeably) as a “millimeter wave” band in documents and articles, despite being different from the extremely high frequency (EHF) band (30 GHz - 300 GHz) which is identified by the International Telecommunications Union (ITU) as a “millimeter wave” band. 
     The frequencies between FR 1  and FR 2  are often referred to as mid-band frequencies. Recent 5G NR studies have identified an operating band for these mid-band frequencies as frequency range designation FR 3  (7.125 GHz - 24.25 GHz). Frequency bands falling within FR 3  may inherit FR 1  characteristics and/or FR 2  characteristics, and thus may effectively extend features of FR 1  and/or FR 2  into mid-band frequencies. In addition, higher frequency bands are currently being explored to extend 5G NR operation beyond 52.6 GHz. For example, three higher operating bands have been identified as frequency range designations FR 4   a  or FR 4 - 1  (52.6 GHz - 71 GHz), FR 4  (52.6 GHz - 114.25 GHz), and FR 5  (114.25 GHz - 300 GHz). Each of these higher frequency bands falls within the EHF band. 
     With the above examples in mind, unless specifically stated otherwise, it should be understood that the term “sub-6 GHz” or the like, if used herein, may broadly represent frequencies that may be less than 6 GHz, may be within FR 1 , or may include mid-band frequencies. Further, unless specifically stated otherwise, it should be understood that the term “millimeter wave” or the like, if used herein, may broadly represent frequencies that may include mid-band frequencies, may be within FR 2 , FR 4 , FR 4 - a  or FR 4 - 1 , and/or FR 5 , or may be within the EHF band. It is contemplated that the frequencies included in these operating bands (e.g., FR 1 , FR 2 , FR 3 , FR 4 , FR 4 - a , FR 4 - 1 , and/or FR 5 ) may be modified, and techniques described herein are applicable to those modified frequency ranges. 
     In some aspects, the UE  120  may include a communication manager  140 . As described in more detail elsewhere herein, the communication manager  140  may receive an indication of a first set of resources for feedback and an indication of a second set of resources for feedback, wherein the second set of resources are associated with a smaller quantity of cyclic shifts than the first set of resources, and transmit feedback on either the first set of resources or the second set of resources based at least in part on a distance associated with the feedback. Additionally, or alternatively, the communication manager  140  may determine a first set of resources for feedback and a second set of resources for feedback, wherein the second set of resources are associated with a smaller quantity of cyclic shifts than the first set of resources, and transmit an indication of the first set of resources and an indication of the second set of resources. 
     Additionally, or alternatively, the communication manager  140  may compute a timing advance associated with transmission of feedback and transmit feedback that is shifted in time according to the timing advance. Additionally, or alternatively, the communication manager  140  may transmit information associated with at least one distance threshold (e.g., to another UE) for long-range sidelink feedback and transmit an indication associated with a plurality of sets of minimum communication ranges (MCRs) (e.g., to the other UE). Additionally, or alternatively, the communication manager  140  may receive an indication of a first set of resources and an indication of a second set of resources, wherein the second set of resources are associated with a smaller quantity of cyclic shifts in demodulation reference signals (DMRSs) than the first set of resources, and transmit DMRSs on either the first set of resources or the second set of resources based at least in part on a distance associated with the DMRSs. Additionally, or alternatively, the communication manager  140  may determine a first set of resources and a second set of resources, wherein the second set of resources are associated with a smaller quantity of cyclic shifts in DMRSs than the first set of resources, and transmit an indication of the first set of resources and an indication of the second set of resources. Additionally, or alternatively, the communication manager  140  may receive a configuration associated with DMRSs on a sidelink channel and transmit DMRSs that are staggered across symbols, include cyclic shift hopping across symbols, are denser than one DMRS per four resource elements (REs), or a combination thereof. Additionally, or alternatively, the communication manager  140  may determine a configuration associated with DMRSs on a sidelink channel, wherein the configuration is associated with DMRSs that are staggered across symbols, include cyclic shift hopping across symbols, are denser than one DMRS per four REs, or a combination thereof, and transmit the configuration. Additionally, or alternatively, the communication manager  140  may perform one or more other operations described herein. 
     As indicated above,  FIG.  1    is provided as an example. Other examples may differ from what is described with regard to  FIG.  1   . 
       FIG.  2    is a diagram illustrating an example  200  of a base station  110  in communication with a UE  120  in a wireless network  100 , in accordance with the present disclosure. The base station  110  may be equipped with a set of antennas  234   a  through  234   t , such as T antennas (T ≥ 1). The UE  120  may be equipped with a set of antennas  252   a  through  252   r , such as R antennas (R ≥ 1). 
     At the base station  110 , a transmit processor  220  may receive data, from a data source  212 , intended for the UE  120  (or a set of UEs  120 ). The transmit processor  220  may select one or more modulation and coding schemes (MCSs) for the UE  120  based at least in part on one or more channel quality indicators (CQIs) received from that UE  120 . The base station  110  may process (e.g., encode and modulate) the data for the UE  120  based at least in part on the MCS(s) selected for the UE  120  and may provide data symbols for the UE  120 . The transmit processor  220  may process system information (e.g., for semi-static resource partitioning information (SRPI)) and control information (e.g., CQI requests, grants, and/or upper layer signaling) and provide overhead symbols and control symbols. The transmit processor  220  may generate reference symbols for reference signals (e.g., a cell-specific reference signal (CRS) or a DMRS) and synchronization signals (e.g., a primary synchronization signal (PSS) or a secondary synchronization signal (SSS)). A transmit (Tx) multiple-input multiple-output (MIMO) processor  230  may perform spatial processing (e.g., precoding) on the data symbols, the control symbols, the overhead symbols, and/or the reference symbols, if applicable, and may provide a set of output symbol streams (e.g., T output symbol streams) to a corresponding set of modems  232  (e.g., Tmodems), shown as modems  232   a  through  232   t . For example, each output symbol stream may be provided to a modulator component (shown as MOD) of a modem  232 . Each modem  232  may use a respective modulator component to process a respective output symbol stream (e.g., for OFDM) to obtain an output sample stream. Each modem  232  may further use a respective modulator component to process (e.g., convert to analog, amplify, filter, and/or upconvert) the output sample stream to obtain a downlink signal. The modems  232   a  through  232   t  may transmit a set of downlink signals (e.g., T downlink signals) via a corresponding set of antennas  234  (e.g., T antennas), shown as antennas  234   a  through  234   t . 
     At the UE  120 , a set of antennas  252  (shown as antennas  252   a  through  252   r ) may receive the downlink signals from the base station  110  and/or other base stations  110  and may provide a set of received signals (e.g., R received signals) to a set of modems  254  (e.g., R modems), shown as modems  254   a  through  254   r . For example, each received signal may be provided to a demodulator component (shown as DEMOD) of a modem  254 . Each modem  254  may use a respective demodulator component to condition (e.g., filter, amplify, downconvert, and/or digitize) a received signal to obtain input samples. Each modem  254  may use a demodulator component to further process the input samples (e.g., for OFDM) to obtain received symbols. A MIMO detector  256  may obtain received symbols from the modems  254 , may perform MIMO detection on the received symbols if applicable, and may provide detected symbols. A receive processor  258  may process (e.g., demodulate and decode) the detected symbols, may provide decoded data for the UE  120  to a data sink  260 , and may provide decoded control information and system information to a controller/processor  280 . The term “controller/processor” may refer to one or more controllers, one or more processors, or a combination thereof. 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, and/or a CQI parameter, among other examples. In some examples, one or more components of the UE  120  may be included in a housing  284 . 
     The network controller  130  may include a communication unit  294 , a controller/processor  290 , and a memory  292 . The network controller  130  may include, for example, one or more devices in a core network. The network controller  130  may communicate with the base station  110  via the communication unit  294 . 
     One or more antennas (e.g., antennas  234   a  through  234   t  and/or antennas  252   a  through  252   r ) may include, or may be included within, one or more antenna panels, one or more antenna groups, one or more sets of antenna elements, and/or one or more antenna arrays, among other examples. An antenna panel, an antenna group, a set of antenna elements, and/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, and/or one or more antenna elements coupled to one or more transmission and/or reception components, such as one or more components of  FIG.  2   . 
     On the uplink, at the UE  120 , a transmit processor  264  may receive and process data from a data source  262  and control information (e.g., for reports that include RSRP, RSSI, RSRQ, and/or CQI) from the controller/processor  280 . The transmit processor  264  may generate reference symbols for one or more reference signals. The symbols from the transmit processor  264  may be precoded by a TX MIMO processor  266  if applicable, further processed by the modems  254  (e.g., for DFT-s-OFDM or CP-OFDM), and transmitted to the base station  110 . In some examples, the modem  254  of the UE  120  may include a modulator and a demodulator. In some examples, the UE  120  includes a transceiver. The transceiver may include any combination of the antenna(s)  252 , the modem(s)  254 , the MIMO detector  256 , the receive processor  258 , the transmit processor  264 , and/or the TX MIMO processor  266 . The transceiver may be used by a processor (e.g., the controller/processor  280 ) and the memory  282  to perform aspects of any of the methods described herein (e.g., with reference to  FIGS.  5 - 20   ). 
     At the base station  110 , the uplink signals from UE  120  and/or other UEs may be received by the antennas  234 , processed by the modem  232  (e.g., a demodulator component, shown as DEMOD, of the modem  232 ), detected by a MIMO detector  236  if applicable, and further processed by a receive processor  238  to obtain decoded data and control information sent by the UE  120 . The receive processor  238  may provide the decoded data to a data sink  239  and provide the decoded control information to the controller/processor  240 . The base station  110  may include a communication unit  244  and may communicate with the network controller  130  via the communication unit  244 . The base station  110  may include a scheduler  246  to schedule one or more UEs  120  for downlink and/or uplink communications. In some examples, the modem  232  of the base station  110  may include a modulator and a demodulator. In some examples, the base station  110  includes a transceiver. The transceiver may include any combination of the antenna(s)  234 , the modem(s)  232 , the MIMO detector  236 , the receive processor  238 , the transmit processor  220 , and/or the TX MIMO processor  230 . The transceiver may be used by a processor (e.g., the controller/processor  240 ) and the memory  242  to perform aspects of any of the methods described herein (e.g., with reference to  FIGS.  5 - 20   ). 
     The controller/processor  240  of the base station  110 , the controller/processor  280  of the UE  120 , and/or any other component(s) of  FIG.  2    may perform one or more techniques associated with configuring and using sidelink feedback resources, as described in more detail elsewhere herein. For example, the controller/processor  240  of the base station  110 , the controller/processor  280  of the UE  120 , and/or any other component(s) of  FIG.  2    may perform or direct operations of, for example, process  1200  of  FIG.  12   , process  1300  of  FIG.  13   , process  1400  of  FIG.  14   , process  1500  of  FIG.  15   , process  1600  of  FIG.  16   , process  1700  of  FIG.  17   , process  1800  of  FIG.  18   , process  1900  of  FIG.  19   , and/or other processes as described herein. The memory  242  and the memory  282  may store data and program codes for the base station  110  and the UE  120 , respectively. In some examples, the memory  242  and/or the memory  282  may include a non-transitory computer-readable medium storing one or more instructions (e.g., code and/or program code) for wireless communication. For example, the one or more instructions, when executed (e.g., directly, or after compiling, converting, and/or interpreting) by one or more processors of the base station  110  and/or the UE  120 , may cause the one or more processors, the UE  120 , and/or the base station  110  to perform or direct operations of, for example, process  1200  of  FIG.  12   , process  1300  of  FIG.  13   , process  1400  of  FIG.  14   , process  1500  of  FIG.  15   , process  1600  of  FIG.  16   , process  1700  of  FIG.  17   , process  1800  of  FIG.  18   , process  1900  of  FIG.  19   , and/or other processes as described herein. In some examples, executing instructions may include running the instructions, converting the instructions, compiling the instructions, and/or interpreting the instructions, among other examples. In some aspects, the mobile station described herein is the UE  120 , is included in the UE  120 , or includes one or more components of the UE  120  shown in  FIG.  2   . 
     In some aspects, a mobile station (e.g., the UE  120  and/or apparatus  2000  of  FIG.  20   ) may include means for receiving an indication of a first set of resources for feedback and an indication of a second set of resources for feedback, wherein the second set of resources are associated with a smaller quantity of cyclic shifts than the first set of resources; and/or means for transmitting feedback on either the first set of resources or the second set of resources based at least in part on a distance associated with the feedback. In some aspects, the means for the mobile station to perform operations described herein may include, for example, one or more of communication manager  140 , antenna  252 , modem  254 , MIMO detector  256 , receive processor  258 , transmit processor  264 , TX MIMO processor  266 , controller/processor  280 , or memory  282 . Additionally, or alternatively, the mobile station may include means for determining a first set of resources for feedback and a second set of resources for feedback, wherein the second set of resources are associated with a smaller quantity of cyclic shifts than the first set of resources; and/or means for transmitting an indication of the first set of resources and an indication of the second set of resources. Additionally, or alternatively, the mobile station may include means for computing a timing advance associated with transmission of feedback; and/or means for transmitting feedback that is shifted in time according to the timing advance. Additionally, or alternatively, the mobile station includes means for transmitting information associated with at least one distance threshold, to a receiving mobile station, for long-range sidelink feedback; and/or means for transmitting an indication associated with a plurality of sets of MCRs to the receiving mobile station. Additionally, or alternatively, the mobile station may include means for receiving an indication of a first set of resources and an indication of a second set of resources, wherein the second set of resources are associated with a smaller quantity of cyclic shifts in DMRSs than the first set of resources; and/or means for transmitting DMRSs on either the first set of resources or the second set of resources based at least in part on a distance associated with the DMRSs. Additionally, or alternatively, the mobile station may include means for determining a first set of resources and a second set of resources, wherein the second set of resources are associated with a smaller quantity of cyclic shifts in DMRSs than the first set of resources; and/or means for transmitting an indication of the first set of resources and an indication of the second set of resources. Additionally, or alternatively, the mobile station may include means for receiving a configuration associated with DMRSs on a sidelink channel; and/or means for transmitting DMRSs that are staggered across symbols, include cyclic shift hopping across symbols, are denser than one DMRS per four REs, or a combination thereof. Additionally, or alternatively, the mobile station may include means for determining a configuration associated with DMRSs on a sidelink channel, wherein the configuration is associated with DMRSs that are staggered across symbols, include cyclic shift hopping across symbols, are denser than one DMRS per four REs, or a combination thereof; and/or means for transmitting the configuration. 
     While blocks in  FIG.  2    are illustrated as distinct components, the functions described above with respect to the blocks may be implemented in a single hardware, software, or combination component or in various combinations of components. For example, the functions described with respect to the transmit processor  264 , the receive processor  258 , and/or the TX MIMO processor  266  may be performed by or under the control of the controller/processor  280 . 
     As indicated above,  FIG.  2    is provided as an example. Other examples may differ from what is described with regard to  FIG.  2   . 
       FIG.  3    is a diagram illustrating an example  300  of resource pools for sidelink communications, in accordance with the present disclosure. Example  300  applies to mobile stations, such as unmanned aerial vehicles (UAVs), UEs  120 , or other mobile devices, communicating with each other on a sidelink channel. 
     As shown in  FIG.  3   , the mobile stations may communicate using frequencies within a carrier bandwidth  301 , where the carrier bandwidth  301  includes a bandwidth part (BWP)  303  for the sidelink (SL) channel between the mobile stations. As used herein, “bandwidth part” or “BWP” refers to a contiguous set of physical resource blocks (PRBs), where each PRB includes a set of frequencies corresponding to one or more subcarriers. A “subcarrier” may refer to a frequency based at least in part on a “carrier” frequency (e.g., a frequency at or near a center of the carrier bandwidth  301 ), and subcarriers may be aggregated to convey information wirelessly (e.g., using OFDM symbols and/or other radio frequency (RF) symbols). 
     As further shown in  FIG.  3   , the SL BWP  303  may include a plurality of resource pools. Example  300  includes resource pools  305   a ,  305   b ,  305   c , and  305   d . Other aspects may include fewer resources pools (e.g., three resources pools, two resource pools, or one resource pool) or additional resource pools (e.g., five resource pools, six resource pools, and so on). The mobile stations may determine the resource pools  305   a ,  305   b ,  305   c , and  305   d  autonomously (e.g., during mode  2  sidelink operation, as defined in 3GPP specifications and/or another standard). As an alternative, a network (e.g., via base station  110 ) may determine the resource pools  305   a ,  305   b ,  305   c , and  305   d  (e.g., during mode  1  sidelink operation, as defined in 3GPP specifications and/or another standard). In some aspects, the resource pools are periodic. For example, as shown in  FIG.  3   , the resource pools  305   a ,  305   b ,  305   c , and  305   d  repeat in time according to resource pool period  307 . 
     As shown in  FIG.  3   , each resource pool includes one or more subchannels (e.g., L subchannels in example  300 ), and each subchannel includes one or more PRBs (e.g., M sub  PRBs in example  300 ). Additionally, each resource pool spans one or more slots across time. As used herein, “slot” refers to a portion of a radio frame (or part of a frame, such as a subframe) within an LTE, 5G, or other wireless communication structure. In some aspects, a slot may include one or more symbols, where “symbol” may refer to an OFDM symbol or other similar symbol within a slot. 
     As indicated above,  FIG.  3    is provided as an example. Other examples may differ from what is described with respect to  FIG.  3   . 
       FIG.  4    is a diagram illustrating an example  400  of resources for sidelink feedback, in accordance with the present disclosure. As shown in  FIG.  4   , a plurality of subchannels  403  from a starting subchannel  401  are allocated for sidelink communications between mobile stations (e.g., by the mobile stations during mode  2  sidelink operation or by a network during mode  1  sidelink operation). Each slot within a subchannel (e.g., slots  405   a  and  405   b  on a third subchannel, slots  405   c  and  405   d  on a first subchannel, or other slots shown in  FIG.  4   ) may be divided between a control channel (e.g., a physical sidelink control channel (PSCCH)) and a data channel (e.g., a physical sidelink shared channel (PSSCH)). 
     As further shown in  FIG.  4   , one or more symbols  407  may be allocated for feedback (e.g., hybrid automatic repeat request (HARQ) feedback) between the mobile stations. Additionally, different resource block (RB) sets (e.g., RB set  409 ) may be associated with different subchannels and/or slots, such that a mobile station may determine to which transmission feedback relates based on which RB set the feedback is received in. In some aspects, the symbols allocated for feedback are periodic. For example, as shown in  FIG.  4   , the symbol(s)  407  repeat in time according to feedback period  411 . 
     Currently, a mobile station selects cyclic shift to apply to feedback signals (e.g., acknowledgement (ACK) or negative-acknowledgement (NACK) signals) from up to six possible cyclic shifts, based on rules defined in 3GPP specifications. However, propagation of feedback signals over long distances results in propagation delays that may be longer than differences between the possible cyclic shifts. For example, with six possible cyclic shifts, a mobile station receiving feedback may be unable to distinguish cyclic shifts beyond 415 meters, assuming free space propagation. As a result, mobile stations are unable to exchange accurate feedback and therefore waste power, processing resources, and network resources when transmitting and receiving feedback. 
     Some techniques and apparatuses described herein enable a mobile station to transmit feedback in resources dedicated for long-range feedback and/or to apply timing advances to feedback to compensate for propagation delay. As a result, a mobile station receiving the feedback is able to accurately decode the feedback, which keeps power, processing resources, and network resources from being wasted. Additionally, the mobile station receiving the feedback is able to accurately determine whether to retransmit communications to the mobile station transmitting the feedback. As a result, reliability of communications between the mobile stations is improved. 
     As indicated above,  FIG.  4    is provided as an example. Other examples may differ from what is described with regard to  FIG.  4   . 
       FIG.  5    is a diagram illustrating an example  500  associated with resources for long-range sidelink feedback, in accordance with the present disclosure. As shown in  FIG.  5   , example  500  a plurality of subchannels  403  from a starting subchannel  401  are allocated for sidelink communications between mobile stations (e.g., by the mobile stations during mode  2  sidelink operation or by a network during mode  1  sidelink operation). Each slot within a subchannel (e.g., slots  405   a  and  405   b  on a third subchannel, slots  405   c  and  405   d  on a first subchannel, or other slots shown in  FIG.  4   ) may be divided between a control channel (e.g., a PSCCH) and a data channel (e.g., a PSSCH). 
     As shown in  FIG.  5   , one or more symbols may be allocated for feedback (e.g., HARQ feedback) between the mobile stations. Additionally, different RB sets (e.g., RB set  409 ) may be associated with different subchannels and/or slots, such that a mobile station may determine to which transmission feedback relates based on which RB set the feedback is received in. In some aspects, the symbols allocated for feedback are periodic. For example, as shown in  FIG.  4   , the symbol(s) repeat in time according to feedback period  411 . 
     As further shown in  FIG.  5   , a Tx mobile station may divide resources for feedback between a set of legacy resources  407  and a set of long-range resources  501 . The long-range resources (e.g., RB set  503 ) may be associated with a smaller quantity of cyclic shifts than the legacy resources (e.g., RB set  409 ). For example, the Tx mobile station may use an sl NumMuxCS-PairLongRange data structure (e.g., to be defined in 3GPP specifications and/or another standard) to indicate the smaller quantity of cyclic shifts to be used in the long-range resources. Accordingly, a receiving (Rx) mobile station uses fewer possible cyclic shifts when transmitting in the long-range resources such that the Tx mobile station may properly decode the feedback despite large propagation delay. 
     In some aspects, the indication of the long-range resources may include a bitmap. For example, the indication may include an sl-PSFCH-LongRangeRB-Set data structure (e.g., to be defined in 3GPP specifications and/or another standard) that indicates which RB sets, of the plurality of RB sets allocated for feedback, are long-range resources. 
     In some aspects, the set of long-range resources is associated with a different period than a period associated with the set of legacy resources. For example, in  FIG.  5   , the feedback period  411  is such that feedback is transmitted after every four slots. However, the feedback period associated with the set of long-range resources may be longer such that feedback is transmitted in the set of long-range resources after every other feedback period  411 , after every third feedback period  411 , or so on. For example, the Tx mobile station may use an sl-PSFCH-LongRangePeriod data structure (e.g., to be defined in 3GPP specifications and/or another standard) to indicate the larger period associated with the set of long-range resources. 
     Accordingly, the Rx mobile station may determine whether to transmit feedback in the set of long-range resources or in the set of legacy resources based at least in part on a distance associated with the feedback. For example, the Rx mobile station may determine the distance as described in connection with  FIG.  6   . The distance may include a three-dimensional distance between the mobile stations and/or a relative height between the mobile stations. 
     By using techniques as described in connection with  FIG.  5   , the Rx mobile station transmits feedback in resources dedicated for long-range feedback (e.g., in the RB set  503 ). As a result, the Tx mobile station is able to accurately decode the feedback, which keeps power, processing resources, and network resources from being wasted. Additionally, the Tx mobile station is able to accurately determine whether to retransmit communications to the Rx mobile station. As a result, reliability of communications between the mobile stations is improved. 
     As indicated above,  FIG.  5    is provided as an example. Other examples may differ from what is described with respect to  FIG.  5   . 
       FIG.  6    is a diagram illustrating an example  600  associated with triggers for long-range sidelink feedback, in accordance with the present disclosure. As shown in  FIG.  6   , example  600  includes a first mobile station (e.g., UE  120   a ) and a second mobile station (e.g., UE  120   b ). The UE  120   a  is sending a transmission over-the-air (OTA) to the second UE  120   b  and will receive feedback based on whether the second UE  120   b  successfully receives and decodes the transmission. 
     The second UE  120   b  may determine whether to use long-range resources to transmit the feedback (e.g., as described in connection with  FIG.  5   ) and/or apply a timing advance to the feedback (e.g., as described in connection with  FIG.  7   ) based at least in part on a three-dimensional distance (e.g., represented by D in example  600 ) between the first UE  120   a  and the second UE  120   b . For example, the second UE  120   b  may apply a distance threshold to make the determination. The distance threshold may be programmed (and/or otherwise preconfigured) into the second UE  120   b  (e.g., according to 3GPP specifications and/or another standard), indicated by the first UE  120   a , or selected from a plurality of distance thresholds (e.g., programmed and/or otherwise preconfigured into the second UE  120   b , according to 3GPP specifications and/or another standard) by the first UE  120   a  and/or the second UE  120   b . 
     To determine the three-dimensional distance, the first UE  120   a  may include a zone identifier (ID) associated with the first UE  120   a  as well as a height of the first UE  120   a  in sidelink control information (SCI) associated with the transmission. For example, “zone ID” may include any numerical identification of a two-dimensional geographic zone in which the first UE  120   a  is located and that is unique within a set of zone IDs used by the first UE  120   a  and the second UE  120   b . In some aspects, a zone ID may be assigned by the first UE  120   a  and indicated to the second UE  120   b . As an alternative, a zone ID may be calculated using coordinates (e.g., global positioning system (GPS) coordinates and/or coordinates with respect to another set of reference axes) that are on one or more boundaries of the geographic zone and/or included in the geographic zone. For example, the zone ID may be calculated using a formula defined in 3GPP specifications and/or another standard. 
     In some aspects, the first UE  120   a  may include the zone ID and the height in second stage SCI (SCI-2). Accordingly, the second UE  120   b  may estimate the distance based at least in part on the zone ID and the height. In some aspects, the first UE  120   a  indicates an absolute height value. As an alternative, the first UE  120   a  transmits an index associated with one height interval from a plurality of height intervals (e.g., included in a table or other similar data structure in an SL-ResourcePool data structure, as defined in 3GPP specifications and/or another standard). As used herein, “height interval” refers to a quantization of a height value. For example, the first UE  120   a  may round the height value according to a set of quantized values (the plurality of height intervals), such that a height of 55 feet and a height of 60 feet are rounded to 50 feet while a height of 65 feet and a height of 70 feet are rounded to 75 feet. In another example, the first UE  120   a  may apply a floor function or a ceiling function to quantize the height value (e.g., such that a height of 55 feet and a height of 65 feet are floored to 50 feet while a height of 76 feet and a height of 79 feet are floored to 75 feet or such that a height of 55 feet and a height of 65 feet are ceilinged to 75 feet while a height of 76 feet and a height of 79 feet are ceilinged to 100 feet). Although described using examples with evenly spaced intervals, the first UE  120   a  may alternatively quantize the height value using unevenly spaced intervals. 
     As an alternative, the first UE  120   a  may include a three-dimensional zone ID associated with the first UE  120   a  in SCI associated with the transmission. For example, “three-dimensional zone ID” may include any numerical identification of a two-dimensional geographic zone and a height range associated with first UE  120   a  and that is unique within a set of three-dimensional zone IDs used by the first UE  120   a  and the second UE  120   b . In some aspects, a three-dimensional zone ID may be assigned by the first UE  120   a  and indicated to the second UE  120   b . As an alternative, a three-dimensional zone ID may be calculated using coordinates (e.g., GPS coordinates and/or coordinates with respect to another set of reference axes) that are on one or more boundaries of the geographic zone and/or included in the geographic zone. For example, the three-dimensional zone ID may be calculated using a formula defined in 3GPP specifications and/or another standard. Additionally, a three-dimensional zone ID may be calculated using a height range associated with the geographical zone. Accordingly, the second UE  120   b  may estimate the distance based at least in part on the zone ID. 
     To determine a distance between the first UE  120   a  and the second UE  120   b , the second UE  120   b  may determine a location of the second UE  120   b  (e.g., using triangulation, GPS, and/or another technique associated with determining a location of a mobile device) and estimate a distance from the location of the second UE  120   b  to a three-dimensional geographic zone (based on a zone ID and a height or based on a three-dimensional zone ID) associated with the first UE  120   a . To apply the distance threshold, the second UE  120   b  may determine a maximum distance between the location of the second UE  120   b  and the three-dimensional geographic zone associated with the first UE  120   a , a minimum distance between the location of the second UE  120   b  and the three-dimensional geographic zone associated with the first UE  120   a , a median distance between the location of the second UE  120   b  and the three-dimensional geographic zone associated with the first UE  120   a , an average distance between the location of the second UE  120   b  and the three-dimensional geographic zone associated with the first UE  120   a , and/or otherwise select one of the distances from the location of the second UE  120   b  to a point in the three-dimensional geographic zone associated with the first UE  120   a . 
     Additionally, or alternatively, the second UE  120   b  may receive a DMRS from the first UE  120   a  (e.g., encoded with the transmission and/or SCI associated with the transmission). Accordingly, the second UE  120   b  may estimate the distance based at least in part on the DMRS. For example, the second UE  120   b  may detect a phase shift in the DMRS caused by the propagation delay and estimate the distance accordingly. 
     In some aspects, the second UE  120   b  transmits feedback to the first UE  120   a  when within an MCR. For example, “MCR” may include a distance threshold within which any UEs should attempt to decode sidelink signals from the first UE  120   a  and transmit feedback to the first UE  120   a  associated with the sidelink signals. 
     In some aspects, when the transmission is a groupcast from the first UE  120   a , the first UE  120   a  may indicate an MCR (e.g., using an sl-ZoneConfigMCR-Index variable in SCI associated with the transmission that maps to a table or other similar data structure in an SL-ResourcePool data structure, as defined in 3GPP specifications and/or another standard) such that the second UE  120   b  transmits feedback when the second UE  120   b  is within the MCR. As used herein, “within the MCR” refers to when a distance between the second UE  120   b  and the first UE  120   a  is less than (or, in some aspects, equal to) the MCR. 
     In some aspects, the first UE  120   a  may select from a different set of MCRs when at a smaller relative height difference with the second UE  120   b  (e.g. represented by Δh in example  600 ) as compared with a larger relative height difference. For example, larger MCRs may be useful for larger relative height differences because signals are less likely to be blocked or otherwise experience interference. Accordingly, the first UE  120   a  may indicate multiple sets of MCRs in an SL-ResourcePool data structure, as defined in 3GPP specifications and/or another standard, where each set of MCRs is associated with a different relative height (or interval of relative heights). Accordingly, the first UE  120   a  and/or the second UE  120   b  may select an MCR from the set of MCRs corresponding to Δh between the first UE  120   a  and the second UE  120   b . The second UE  120   b  may therefore determine whether to transmit the feedback based at least in part on the selected MCR. Similarly, the first UE  120   a  and/or the second UE  120   b  may select a distance threshold from the set of distance thresholds based at least in part on Δh between the first UE  120   a  and the second UE  120   b . 
     By using techniques as described in connection with  FIG.  6   , the Rx mobile station determines when to transmit feedback in resources dedicated for long-range feedback and/or when to apply timing advances to feedback to compensate for propagation delay. As a result, the Tx mobile station is able to accurately decode the feedback, which keeps power, processing resources, and network resources from being wasted. Additionally, the Tx mobile station is able to accurately determine whether to retransmit communications to the Rx mobile station. As a result, reliability of communications between the mobile stations is improved. 
     As indicated above,  FIG.  6    is provided as an example. Other examples may differ from what is described with respect to  FIG.  6   . 
       FIG.  7    is a diagram illustrating an example  700  associated with resources for long-range sidelink feedback, in accordance with the present disclosure. As shown in  FIG.  7   , example  700  includes a slot  701  that is divided between a sidelink control channel (e.g., a PSCCH), a sidelink data channel (e.g., a PSSCH), and a feedback channel (e.g., a PSFCH). In addition to, or in lieu of, using a reduced quantity of cyclic shifts such that feedback may be decoded over longer distances, an Rx mobile station may compute a timing advance (TA) associated with transmission of the feedback. For example, the Rx mobile station may estimate a distance to a Tx mobile station (e.g., as described in connection with  FIG.  6   ) and determine the TA to apply based at least in part on the distance. 
     Accordingly, as shown by reference number  703 , the Rx mobile station may transmit the feedback shifted in time according to the timing advance (e.g., represented by t TA  in example  700 ). For example, the Rx mobile station may transmit the feedback earlier in time (e.g., before a scheduled end of a gap between a transmission, such as a PSSCH transmission in example  700 ). Accordingly, the Rx mobile station may account for the propagation delay of the feedback such that the Tx mobile station can still distinguish possible cyclic shifts for the feedback. 
     By using techniques as described in connection with  FIG.  7   , the Rx mobile station applies timing advances to feedback to compensate for propagation delay. As a result, the Tx mobile station is able to accurately decode the feedback, which keeps power, processing resources, and network resources from being wasted. Additionally, the Tx mobile station is able to accurately determine whether to retransmit communications to the Rx mobile station. As a result, reliability of communications between the mobile stations is improved. 
     As described above, examples  500  and  700  may be combined. For example, the Rx mobile station may apply a timing advance to the feedback and also transmit the feedback in a set of resources that are associated with fewer possible cyclic shifts. 
     As indicated above,  FIG.  7    is provided as an example. Other examples may differ from what is described with respect to  FIG.  7   . 
       FIG.  8    is a diagram illustrating an example  800  associated with configuration of long-range sidelink feedback between mobile stations, in accordance with the present disclosure. As shown in  FIG.  8   , a UE  120   a  and a UE  120   b  may communicate with one another (e.g., on a sidelink). 
     As shown by reference number  805 , a Tx UE (e.g., the UE  120   a ) may transmit, and an Rx UE (e.g., the UE  120   b ) may receive, a configuration associated with feedback from the Rx UE  120   b . For example, as described in connection with  FIG.  6   , the configuration may include an indication of a first set of resources for feedback and a second set of resources for feedback, where the second set of resources are associated with a smaller quantity of cyclic shifts than the first set of resources. For example, the configuration may include an SL-PSFCH-Config data structure (e.g., as defined in 3GPP specifications and/or another standard) that indicates the first set of resources and the second set of resources. 
     Additionally, or alternatively, the configuration may include information associated with at least one distance threshold used to determine whether to use the first set of resources or the second set of resources for transmitting feedback and/or whether to apply a TA to feedback (e.g., as described in connection with  FIG.  7   ). For example, the configuration may include an SL-ResourcePool data structure (e.g., as defined in 3GPP specifications and/or another standard) that indicates a single distance threshold or a plurality of distance thresholds from which the Rx UE  120   b  may select (e.g., based at least in part on a relative height difference, as described in connection with  FIG.  6   ). 
     In some aspects, the configuration may further include an indication associated with a plurality of sets of MCRs (e.g., as described in connection with  FIG.  6   ). For example, the configuration may include an SL-ResourcePool data structure (e.g., as defined in 3GPP specifications and/or another standard) that indicates a plurality of sets of MCRs from which the Tx UE  120   a  and/or the Rx UE  120   b  may select based at least in part on a relative height difference, as described in connection with  FIG.  6   . 
     As shown by reference number  810 , the Tx UE  120   a  may transmit, and the Rx UE  120   b  may receive, data. For example, the Tx UE  120   a  may transmit the data on a PSSCH after scheduling the transmission with SCI on a PSCCH. 
     As shown by reference number  815 , the Rx UE  120   b  may transmit, and the Tx UE  120   a  may receive, feedback associated with the data. For example, the Rx UE  120   b  may determine whether to transmit the feedback based at least in part on a selected MCR (e.g., as described in connection with  FIG.  6   ). Additionally, the Rx UE  120   b  may determine whether to use the first set of resources or the second set of resources (e.g., as described in connection with  FIG.  5   ) and/or whether to apply a TA (e.g., as described in connection with  FIG.  7   ) based at least in part on a selected distance threshold. Accordingly, the Tx UE  120   a  is able to receive and accurately decode the feedback. 
     By using techniques as described in connection with  FIG.  8   , the Tx mobile station  120   a  configures the Rx mobile station  120   b  to transmit feedback in resources dedicated for long-range feedback and/or to apply timing advances to feedback to compensate for propagation delay. As a result, the Tx mobile station  120   a  is able to accurately decode the feedback, which keeps power, processing resources, and network resources from being wasted. Additionally, the Tx mobile station  120   a  is able to accurately determine whether to retransmit communications to the Rx mobile station  120   b . As a result, reliability of communications between the mobile stations  120   a  and  120   b  is improved. 
     As indicated above,  FIG.  8    is provided as an example. Other examples may differ from what is described with respect to  FIG.  8   . 
     Currently, a mobile station selects from three possible cyclic shifts to apply to DMRSs based on rules defined in 3GPP specifications. However, propagation of feedback signals over long distances results in propagation delays that may be longer than differences between the possible cyclic shifts. For example, with three possible cyclic shifts, a mobile station receiving a DMRS may be unable to distinguish cyclic shifts beyond 825 meters, assuming free space propagation. As a result, mobile stations may suffer reduced quality and reliability of communications by being unable to properly demodulate and decode transmissions using DMRSs. This wastes power, processing resources, and network resources. 
     Some techniques and apparatuses described herein enable a transmitting mobile station to transmit DMRSs in resources dedicated for long-range DMRSs and/or to use staggering across symbols, hopping across symbols, and/or a greater density than one DMRS per four REs to compensate for propagation delay. As a result, a receiving mobile station is able to use the DMRSs for more accurate decoding, which keeps power, processing resources, and network resources from being wasted. Additionally, quality of communications between the mobile stations is improved. 
       FIGS.  9 A and  9 B  are diagrams illustrating examples  900  and  950 , respectively, associated with density and staggering of DMRSs, in accordance with the present disclosure. As shown in  FIG.  9 A , example  900  includes a set of OFDM symbols  901  that include DMRSs with a density greater than one DMRS per four REs in frequency. By using greater than one DMRS per four REs in frequency, a Tx mobile station enables an Rx mobile station to distinguish between DMRSs from the Tx mobile station and DMRSs from other mobile stations at a longer range proportionate with the increase in density. 
     Additionally, or alternatively, as shown in  FIG.  9 B , example  950  includes a set of OFDM symbols  951  that include DMRSs that are staggered across symbols. For example, in a first symbol, a Tx mobile station encodes DMRSs in a first RBs, a fifth RB, and a ninth RB; in a second symbol, the Tx mobile station encodes DMRSs in a second RB, a sixth RB, and a tenth RB; and, in a third symbol, the Tx mobile station encodes DMRSs in a third RB, a seventh RB, and an eleventh RB. By staggering the DMRSs, the Tx mobile station enables an Rx mobile station to distinguish between DMRSs from the Tx mobile station and DMRSs from other mobile stations at a longer range. 
     In order to use a greater density and/or staggering across symbols, the Rx mobile station may transmit, and the Tx mobile station may receive, a configuration associated with DMRSs that indicates a density to use and/or a pattern for staggering such that the Rx mobile station may successfully demodulate and decode data from the Tx mobile station using the increased density and/or the pattern of staggered DMRSs. 
     By using techniques as described in connection with  FIGS.  9 A and/or  9 B , a Tx mobile station uses staggering across symbols and/or a greater density than one DMRS per four REs to compensate for propagation delay. As a result, an Rx mobile station is able to use the DMRSs for more accurate decoding, which keeps power, processing resources, and network resources from being wasted. Additionally, quality of communications between the mobile stations is improved. 
     As indicated above,  FIGS.  9 A and  9 B  are provided as examples. Other examples may differ from what is described with respect to  FIGS.  9 A and  9 B . 
       FIG.  10    is a diagram illustrating an example  1000  associated with DMRS hopping across symbols, in accordance with the present disclosure. As shown in  FIG.  10   , example  1000  includes a set of OFDM symbols  1001  that include DMRSs that are hopped across symbols. In example  1000 , a first Tx mobile station (shown as “UE0”) encodes DMRSs in a second RB and a fourteenth RB in a first symbol, in a tenth RB in a second symbol, and in a sixth RB in a third symbol. Similarly, a second Tx mobile station (shown as “UE1”) encodes DMRSs in a tenth RB in the first symbol, in a sixth RB in the second symbol, and in a second RB and a fourteenth RB in the third symbol. Similarly, a third Tx mobile station (shown as “UE2”) encodes DMRSs in a sixth RB in the first symbol, in a second RB and a fourteenth RB in the second symbol, and in a tenth RB in the third symbol. By hopping the DMRSs, the Tx mobile stations enable an Rx mobile station to distinguish between DMRSs from different mobile stations at a longer range. For example, the Rx mobile station may coherently combine across the three symbols to perform decoding. Although described using three mobile stations and three symbols, other aspects may include additional mobile stations (e.g., four mobile stations, five mobile stations, and so on) and/or additional symbols (e.g., four symbols, five symbols, and so on). 
     As an alternative, the Tx mobile stations may hop the DMRSs across symbols according to a pattern such that the Rx mobile station may determine cyclic shifts associated with the DMRSs based at least in part on the pattern. For example, the Rx mobile station may determine that a first pattern of cyclic shifts (e.g., applying cyclic shift  1  in a first symbol, applying cyclic shift  1  in a second symbol, and applying cyclic shift  2  in a third symbol) is associated with an overall cyclic shift  1 ; a second pattern of cyclic shifts (e.g., applying cyclic shift  2  in a first symbol, applying cyclic shift  3  in a second symbol, and applying cyclic shift  3  in a third symbol) is associated with an overall cyclic shift  2 ; and a third pattern of cyclic shifts (e.g., applying cyclic shift  3  in a first symbol, applying cyclic shift  2  in a second symbol, and applying cyclic shift  1  in a third symbol) is associated with an overall cyclic shift  3 . By hopping the DMRSs, the Tx mobile stations enable an Rx mobile station to determine an overall cyclic shift for DMRSs from different mobile stations at a longer range. Although described using three symbols, other aspects may include additional symbols (e.g., four symbols, five symbols, and so on). 
     In order to use hopping across symbols, the Rx mobile station may transmit, and the Tx mobile station may receive, a configuration associated with DMRSs that indicates a pattern for hopping such that the Rx mobile station may successfully demodulate and decode data from the Tx mobile station using the pattern of hopped DMRSs. 
     By using techniques as described in connection with  FIG.  10   , a Tx mobile station uses hopping across symbols to compensate for propagation delay. As a result, an Rx mobile station is able to use the DMRSs for more accurate decoding, which keeps power, processing resources, and network resources from being wasted. Additionally, quality of communications between the mobile stations is improved. 
     As indicated above,  FIG.  10    is provided as an example. Other examples may differ from what is described with respect to  FIG.  10   . 
       FIG.  11    is a diagram illustrating an example  1100  associated with configuration of DMRSs between mobile stations, in accordance with the present disclosure. As shown in  FIG.  11   , a UE  120   a  and a UE  120   b  may communicate with one another (e.g., on a sidelink). 
     As shown by reference number  1105   a , an Rx UE (e.g., the UE  120   a ) may transmit, and a Tx UE (e.g., the UE  120   b ) may receive, a configuration associated with DMRSs on the sidelink channel. In some aspects, the configuration may include an indication of a first set of resources and an indication of a second set of resources, where the second set of resources are associated with a smaller quantity of cyclic shifts in DMRSs than the first set of resources. 
     In some aspects, the first set of resources includes a first resource pool, and the second set of resources includes a second resource pool. For example, the configuration may include an SL-ResourcePool data structure (e.g., as defined in 3GPP specifications and/or another standard) that indicates the first set of resources and an SL-ResourcePool data structure (e.g., as defined in 3GPP specifications and/or another standard) that indicates the second set of resources. Additionally, the configuration may include an sl-NumCyclicShifts parameter (e.g., to be defined in 3GPP specifications and/or another standard) that indicates a quantity of cyclic shifts for DMRSs in the first set of resources and an sl-NumCyclicShifts parameter (e.g., to be defined in 3GPP specifications and/or another standard) that indicates a quantity of cyclic shifts for DMRSs in the second set of resources. 
     As an alternative, the first set of resources includes a first subchannel, and the second set of resources includes a second subchannel. For example, the configuration may be programmed (and/or otherwise preconfigured) into the Rx UE  120   a  and the Tx UE  120   b  or may be included in system information block (SIB) (such as SIB-12, as defined in 3GPP specifications). As an alternative, the configuration may be included in a radio resource control (RRC) message (such as an sl-ConfigDedicatedNR data structure, as defined in 3GPP specifications and/or another standard). For example, the configuration may include an sl-startRb-longrange parameter indicating an initial RB associated with the second subchannel and an sl-NumSubchannel-longrange parameter indicating a range of RBs associated with the second subchannel (e.g., to be defined in 3GPP specifications and/or another standard). 
     As an alternative, and as shown by reference number  1105   b , the Rx UE  120   a  may transmit, and the Tx UE  120   b  may receive, a message indicating that the Rx UE  120   a  is capable of performing decoding using multiple cyclic shift hypotheses. Accordingly, the Tx UE  120   b  may transmit data to the Rx UE  120   a  without using separate resources based on distance and without reducing a quantity of possible cyclic shifts. 
     Accordingly, as shown by reference number  1110 , the Tx UE  120   b  may transmit, and the Rx UE  120   a  may receive, data. The Tx UE  120   b  may transmit the data with DMRSs such that the Rx UE  120   a  may demodulate and decode the data, as shown by reference number  1115 . 
     In some aspects, the Tx UE  120   b  may transmit DMRSs on either the first set of resources or the second set of resources based at least in part on a distance associated with the DMRSs (e.g., determined similarly as described in connection with  FIG.  6   ). As an alternative, when the Rx UE  120   a  is capable of considering all possible cyclic shifts in parallel to decode the data, the Tx UE  120   b  may transmit the DMRSs regardless of the distance associated with the DMRSs. 
     By using techniques as described in connection with  FIG.  11   , the Rx mobile station  120   a  configures the Tx mobile station  120   b  to transmit DMRSs in resources dedicated for long-range DMRSs and/or uses multiple cyclic shift hypotheses to compensate for propagation delay. As a result, the Rx mobile station  120   a  is able to use the DMRSs for more accurate decoding, which keeps power, processing resources, and network resources from being wasted. Additionally, quality of communications between the mobile stations  120   a  and  120   b  is improved. 
     As indicated above,  FIG.  11    is provided as an example. Other examples may differ from what is described with respect to  FIG.  11   . 
       FIG.  12    is a diagram illustrating an example process  1200  performed, for example, by a mobile station, in accordance with the present disclosure. Example process  1200  is an example where the mobile station (e.g., UE  120  and/or apparatus  2000  of  FIG.  20   ) performs operations associated with using sidelink feedback resources. 
     As shown in  FIG.  12   , in some aspects, process  1200  may include receiving an indication of a first set of resources for feedback and an indication of a second set of resources for feedback (block  1205 ). For example, the mobile station (e.g., using communication manager  140  and/or reception component  2002 , depicted in  FIG.  20   ) may receive an indication of a first set of resources for feedback and an indication of a second set of resources for feedback, as described in connection with  FIGS.  5 - 8   . In some aspects, the second set of resources are associated with a smaller quantity of cyclic shifts than the first set of resources. The indication may be received from another mobile station and/or from a memory of the mobile station (e.g., configured according to 3GPP specifications and/or another standard). 
     In some aspects, as further shown in  FIG.  12   , process  1200  may include receiving SCI that indicates a zone identifier and a height associated with a receiver for the feedback (block  1210 ). For example, the mobile station (e.g., using communication manager  140  and/or reception component  2002 ) may receive SCI that indicates a zone identifier and a height associated with a receiver for the feedback, as described in connection with  FIGS.  5 - 8   . In some aspects, the distance associated with feedback is based at least in part on the zone identifier and the height. 
     Additionally, in some aspects, process  1200  may include receiving a plurality of height intervals (block  1215 ). For example, the mobile station (e.g., using communication manager  140  and/or reception component  2002 ) may receive a plurality of height intervals, as described in connection with  FIGS.  5 - 8   . In some aspects, the height indicated in the SCI includes an index associated with one of the plurality of height intervals. The plurality of height intervals may be received from another mobile station and/or from a memory of the mobile station (e.g., configured according to 3GPP specifications and/or another standard). 
     Additionally, or alternatively, in some aspects, process  1200  may include receiving SCI that indicates a three-dimensional zone identifier associated with a receiver for the feedback (block  1220 ). For example, the mobile station (e.g., using communication manager  140  and/or reception component  2002 ) may receive SCI that indicates a three-dimensional zone identifier associated with a receiver for the feedback, as described in connection with  FIGS.  5 - 8   . In some aspects, the distance associated with feedback is based at least in part on the three-dimensional zone identifier. 
     Additionally, or alternatively, in some aspects, process  1200  may include receiving at least one DMRS from a receiver for the feedback (block  1225 ). For example, the mobile station (e.g., using communication manager  140  and/or reception component  2002 ) may receive at least one DMRS from a receiver for the feedback, as described in connection with  FIGS.  5 - 8   . In some aspects, the distance associated with feedback is determined based at least in part on the at least one DMRS. 
     Additionally, or alternatively, in some aspects, process  1200  may include receiving an indication of a distance threshold (block  1230 ). For example, the mobile station (e.g., using communication manager  140  and/or reception component  2002 ) may receive an indication of a distance threshold, as described in connection with  FIGS.  5 - 8   . In some aspects, the second set of resources is used when the distance satisfies the distance threshold. 
     Additionally, or alternatively, in some aspects, process  1200  may include receiving a plurality of distance thresholds and selecting one distance threshold of the plurality of distance thresholds based at least in part on a relative height associated with a receiver for the feedback (block  1235 ). For example, the mobile station (e.g., using communication manager  140 , reception component  2002 , and/or selection component  2008 , depicted in  FIG.  20   ) may receive a plurality of distance thresholds and select one distance threshold of the plurality of distance thresholds, as described in connection with  FIGS.  5 - 8   . The plurality of distance thresholds may be received from another mobile station and/or from a memory of the mobile station (e.g., configured according to 3GPP specifications and/or another standard). 
     In some aspects, the second set of resources is used when the distance satisfies the distance threshold. The mobile station may select the one distance threshold based at least in part on a relative height associated with a receiver for the feedback. As an alternative, the mobile station may receive, from the receiver for the feedback, an indication of the one distance threshold, of the plurality of distance thresholds, to use. 
     Additionally, or alternatively, in some aspects, process  1200  may include receiving a plurality of MCRs and selecting the MCR from the plurality of MCRs based at least in part on a relative height associated with a receiver for the feedback (block  1240 ). For example, the mobile station (e.g., using communication manager  140 , reception component  2002 , and/or selection component  2008 ) may receive a plurality of MCRs and select the MCR from the plurality of MCRs based at least in part on a relative height associated with a receiver for the feedback, as described in connection with  FIGS.  5 - 8   . In some aspects, the feedback is transmitted based at least in part on the selected MCR associated with the feedback. The plurality of MCRs may be received from another mobile station and/or from a memory of the mobile station (e.g., configured according to 3GPP specifications and/or another standard). 
     As further shown in  FIG.  12   , in some aspects, process  1200  may include transmitting feedback on either the first set of resources or the second set of resources based at least in part on a distance associated with the feedback (block  1245 ). For example, the mobile station (e.g., using communication manager  140  and/or transmission component  2004 , depicted in  FIG.  20   ) may transmit feedback on either the first set of resources or the second set of resources based at least in part on a distance associated with the feedback, as described in connection with  FIGS.  5 - 8   . 
     Process  1200  may include additional aspects, such as any single aspect or any combination of aspects described below and/or in connection with one or more other processes described elsewhere herein. 
     In a first aspect, the indication of the second set of resources includes a bitmap. 
     In a second aspect, alone or in combination with the first aspect, the second set of resources is associated with a different period than a period associated with the first set of resources. 
     Although  FIG.  12    shows example blocks of process  1200 , in some aspects, process  1200  may include additional blocks, fewer blocks, different blocks, or differently arranged blocks than those depicted in  FIG.  12   . Additionally, or alternatively, two or more of the blocks of process  1200  may be performed in parallel. 
       FIG.  13    is a diagram illustrating an example process  1300  performed, for example, by a mobile station, in accordance with the present disclosure. Example process  1300  is an example where the mobile station (e.g., UE  120  and/or apparatus  2000  of  FIG.  20   ) performs operations associated with configuring sidelink feedback resources. 
     As shown in  FIG.  13   , in some aspects, process  1300  may include determining a first set of resources for feedback and a second set of resources for feedback (block  1310 ). For example, the mobile station (e.g., using communication manager  140  and/or determination component  2010 , depicted in  FIG.  20   ) may determine a first set of resources for feedback and a second set of resources for feedback, as described in connection with  FIGS.  5 - 8   . In some aspects, the second set of resources are associated with a smaller quantity of cyclic shifts than the first set of resources. 
     As further shown in  FIG.  13   , in some aspects, process  1300  may include transmitting an indication of the first set of resources and an indication of the second set of resources (block  1320 ). For example, the mobile station (e.g., using communication manager  140  and/or transmission component  2004 , depicted in  FIG.  20   ) may transmit an indication of the first set of resources and an indication of the second set of resources, as described in connection with  FIGS.  5 - 8   . 
     Process  1300  may include additional aspects, such as any single aspect or any combination of aspects described below and/or in connection with one or more other processes described elsewhere herein. 
     In a first aspect, the indication of the second set of resources comprises a bitmap. 
     In a second aspect, alone or in combination with the first aspect, the second set of resources is associated with a different period than a period associated with the first set of resources. 
     Although  FIG.  13    shows example blocks of process  1300 , in some aspects, process  1300  may include additional blocks, fewer blocks, different blocks, or differently arranged blocks than those depicted in  FIG.  13   . Additionally, or alternatively, two or more of the blocks of process  1300  may be performed in parallel. 
       FIG.  14    is a diagram illustrating an example process  1400  performed, for example, by a mobile station, in accordance with the present disclosure. Example process  1400  is an example where the mobile station (e.g., UE  120  and/or apparatus  2000  of  FIG.  20   ) performs operations associated with using sidelink feedback resources. 
     As shown in  FIG.  14   , in some aspects, process  1400  may include computing a timing advance associated with transmission of feedback (block  1405 ). For example, the mobile station (e.g., using communication manager  140  and/or computation component  2012 , depicted in  FIG.  20   ) may compute a timing advance associated with transmission of feedback, as described in connection with  FIGS.  5 - 8   . 
     In some aspects, as further shown in  FIG.  14   , process  1400  may include receiving SCI that indicates a zone identifier and a height associated with a receiver for the feedback (block  1410 ). For example, the mobile station (e.g., using communication manager  140  and/or reception component  2002 ) may receive SCI that indicates a zone identifier and a height associated with a receiver for the feedback, as described in connection with  FIGS.  5 - 8   . In some aspects, the timing advance associated with the transmission of the feedback is based at least in part on the zone identifier and the height. 
     Additionally, in some aspects, process  1400  may include receiving a plurality of height intervals (block  1415 ). For example, the mobile station (e.g., using communication manager  140  and/or reception component  2002 ) may receive a plurality of height intervals, as described in connection with  FIGS.  5 - 8   . In some aspects, the height indicated in the SCI includes an index associated with one of the plurality of height intervals. The plurality of height intervals may be received from another mobile station and/or from a memory of the mobile station (e.g., configured according to 3GPP specifications and/or another standard). 
     Additionally, or alternatively, in some aspects, process  1400  may include receiving SCI that indicates a three-dimensional zone identifier associated with a receiver for the feedback (block  1420 ). For example, the mobile station (e.g., using communication manager  140  and/or reception component  2002 ) may receive SCI that indicates a three-dimensional zone identifier associated with a receiver for the feedback, as described in connection with  FIGS.  5 - 8   . In some aspects, the timing advance associated with the transmission of the feedback is based at least in part on the three-dimensional zone identifier. 
     Additionally, or alternatively, in some aspects, process  1400  may include receiving at least one DMRS from a receiver for the feedback (block  1425 ). For example, the mobile station (e.g., using communication manager  140  and/or reception component  2002 ) may receive at least one DMRS from a receiver for the feedback, as described in connection with  FIGS.  5 - 8   . In some aspects, the timing advance associated with the transmission of the feedback is based at least in part on a distance associated with the feedback and determined based at least in part on the at least one DMRS. 
     Additionally, or alternatively, in some aspects, process  1400  may include receiving an indication of a distance threshold (block  1430 ). For example, the mobile station (e.g., using communication manager  140  and/or reception component  2002 ) may receive an indication of a distance threshold, as described in connection with  FIGS.  5 - 8   . In some aspects, the timing advance associated with the transmission of the feedback is applied when a distance associated with the feedback satisfies the distance threshold. 
     Additionally, or alternatively, in some aspects, process  1400  may include receiving a plurality of distance thresholds and selecting one distance threshold of the plurality of distance thresholds based at least in part on a relative height associated with a receiver for the feedback (block  1435 ). For example, the mobile station (e.g., using communication manager  140 , reception component  2002 , and/or selection component  2008 , depicted in  FIG.  20   ) may receive a plurality of distance thresholds and select one distance threshold of the plurality of distance thresholds, as described in connection with  FIGS.  5 - 8   . The plurality of distance thresholds may be received from another mobile station and/or from a memory of the mobile station (e.g., configured according to 3GPP specifications and/or another standard). 
     In some aspects, the timing advance associated with the transmission of the feedback is applied when a distance associated with the feedback satisfies the distance threshold. The mobile station may select the one distance threshold based at least in part on a relative height associated with a receiver for the feedback. As an alternative, the mobile station may receive, from the receiver for the feedback, an indication of the one distance threshold, of the plurality of distance thresholds, to use. 
     Additionally, or alternatively, in some aspects, process  1400  may include receiving a plurality of MCRs and selecting the MCR from the plurality of MCRs based at least in part on a relative height associated with a receiver for the feedback (block  1440 ). For example, the mobile station (e.g., using communication manager  140 , reception component  2002 , and/or selection component  2008 ) may receive a plurality of MCRs and select the MCR from the plurality of MCRs based at least in part on a relative height associated with a receiver for the feedback, as described in connection with  FIGS.  5 - 8   . In some aspects, the feedback is transmitted based at least in part on the selected MCR associated with the feedback. The plurality of MCRs may be received from another mobile station and/or from a memory of the mobile station (e.g., configured according to 3GPP specifications and/or another standard). 
     As further shown in  FIG.  14   , in some aspects, process  1400  may include transmitting feedback that is shifted in time according to the timing advance (block  1445 ). For example, the mobile station (e.g., using communication manager  140  and/or transmission component  2004 , depicted in  FIG.  20   ) may transmit feedback that is shifted in time according to the timing advance, as described in connection with  FIGS.  5 - 8   . 
     Process  1400  may include additional aspects, such as any single aspect or any combination of aspects described below and/or in connection with one or more other processes described elsewhere herein. 
     Although  FIG.  14    shows example blocks of process  1400 , in some aspects, process  1400  may include additional blocks, fewer blocks, different blocks, or differently arranged blocks than those depicted in  FIG.  14   . Additionally, or alternatively, two or more of the blocks of process  1400  may be performed in parallel. 
       FIG.  15    is a diagram illustrating an example process  1500  performed, for example, by a mobile station, in accordance with the present disclosure. Example process  1500  is an example where the mobile station (e.g., UE  120  and/or apparatus  2000  of  FIG.  20   ) performs operations associated with configuring sidelink feedback resources. 
     As shown in  FIG.  15   , in some aspects, process  1500  may include transmitting information associated with at least one distance threshold (e.g., to a receiving mobile station, such as another UE and/or another apparatus  2000  of  FIG.  20   ) for long-range sidelink feedback (block  1510 ). For example, the transmitting mobile station (e.g., using communication manager  140  and/or transmission component  2004 , depicted in  FIG.  20   ) may transmit information associated with at least one distance threshold, to a receiving mobile station, for long-range sidelink feedback, as described in connection with  FIGS.  5 - 8   . 
     As further shown in  FIG.  15   , in some aspects, process  1500  may include transmitting an indication associated with a plurality of sets of MCRs to the receiving mobile station (block  1520 ). For example, the transmitting mobile station (e.g., using communication manager  140  and/or transmission component  2004 ) may transmit an indication associated with a plurality of sets of MCRs to the receiving mobile station, as described in connection with  FIGS.  5 - 8   . 
     Process  1500  may include additional aspects, such as any single aspect or any combination of aspects described below and/or in connection with one or more other processes described elsewhere herein. 
     In a first aspect, the at least one distance threshold includes a plurality of distance thresholds, and each distance threshold, of the plurality of distance thresholds, is associated with a corresponding height, and the information indicates a height associated with the transmitting mobile station. 
     In a second aspect, alone or in combination with the first aspect, each set of MCRs, of the plurality of sets of MCRs, is associated with a corresponding height. 
     Although  FIG.  15    shows example blocks of process  1500 , in some aspects, process  1500  may include additional blocks, fewer blocks, different blocks, or differently arranged blocks than those depicted in  FIG.  15   . Additionally, or alternatively, two or more of the blocks of process  1500  may be performed in parallel. 
       FIG.  16    is a diagram illustrating an example process  1600  performed, for example, by a mobile station, in accordance with the present disclosure. Example process  1600  is an example where the mobile station (e.g., UE  120  and/or apparatus  2000  of  FIG.  20   ) performs operations associated with using DMRSs on a sidelink. 
     As shown in  FIG.  16   , in some aspects, process  1600  may include receiving an indication of a first set of resources and an indication of a second set of resources (block  1610 ). For example, the mobile station (e.g., using communication manager  140  and/or reception component  2002 , depicted in  FIG.  20   ) may receive an indication of a first set of resources and an indication of a second set of resources, as described in connection with  FIG.  11   . In some aspects, the second set of resources are associated with a smaller quantity of cyclic shifts in DMRSs than the first set of resources. 
     As further shown in  FIG.  16   , in some aspects, process  1600  may include transmitting DMRSs on either the first set of resources or the second set of resources based at least in part on a distance associated with the DMRSs (block  1620 ). For example, the mobile station (e.g., using communication manager  140  and/or transmission component  2004 , depicted in  FIG.  20   ) may transmit DMRSs on either the first set of resources or the second set of resources based at least in part on a distance associated with the DMRSs, as described in connection with  FIG.  11   . 
     Process  1600  may include additional aspects, such as any single aspect or any combination of aspects described below and/or in connection with one or more other processes described elsewhere herein. 
     In a first aspect, the first set of resources includes a first resource pool, and the second set of resources includes a second resource pool. 
     In a second aspect, alone or in combination with the first aspect, the first set of resources includes a first subchannel, and the second set of resources includes a second subchannel. 
     Although  FIG.  16    shows example blocks of process  1600 , in some aspects, process  1600  may include additional blocks, fewer blocks, different blocks, or differently arranged blocks than those depicted in  FIG.  16   . Additionally, or alternatively, two or more of the blocks of process  1600  may be performed in parallel. 
       FIG.  17    is a diagram illustrating an example process  1700  performed, for example, by a mobile station, in accordance with the present disclosure. Example process  1700  is an example where the mobile station (e.g., UE  120  and/or apparatus  2000  of  FIG.  20   ) performs operations associated with configuring DMRSs on a sidelink. 
     As shown in  FIG.  17   , in some aspects, process  1700  may include determining a first set of resources and a second set of resources (block  1710 ). For example, the mobile station (e.g., using communication manager  140  and/or determination component  2010 , depicted in  FIG.  20   ) may determine a first set of resources and a second set of resources, as described in connection with  FIG.  11   . In some aspects, the second set of resources are associated with a smaller quantity of cyclic shifts in DMRSs than the first set of resources. 
     As further shown in  FIG.  17   , in some aspects, process  1700  may include transmitting an indication of the first set of resources and an indication of the second set of resources (block  1720 ). For example, the mobile station (e.g., using communication manager  140  and/or transmission component  2004 , depicted in  FIG.  20   ) may transmit an indication of the first set of resources and an indication of the second set of resources, as described in connection with  FIG.  11   . 
     Process  1700  may include additional aspects, such as any single aspect or any combination of aspects described below and/or in connection with one or more other processes described elsewhere herein. 
     In a first aspect, the first set of resources includes a first resource pool, and the second set of resources includes a second resource pool. 
     In a second aspect, alone or in combination with the first aspect, the first set of resources includes a first subchannel, and the second set of resources includes a second subchannel. 
     Although  FIG.  17    shows example blocks of process  1700 , in some aspects, process  1700  may include additional blocks, fewer blocks, different blocks, or differently arranged blocks than those depicted in  FIG.  17   . Additionally, or alternatively, two or more of the blocks of process  1700  may be performed in parallel. 
       FIG.  18    is a diagram illustrating an example process  1800  performed, for example, by a mobile station, in accordance with the present disclosure. Example process  1800  is an example where the mobile station (e.g., UE  120  and/or apparatus  2000  of  FIG.  20   ) performs operations associated with using DMRSs on a sidelink. 
     As shown in  FIG.  18   , in some aspects, process  1800  may include receiving a configuration associated with DMRSs on a sidelink channel (block  1810 ). For example, the mobile station (e.g., using communication manager  140  and/or reception component  2002 , depicted in  FIG.  20   ) may receive a configuration associated with DMRSs on a sidelink channel, as described in connection with  FIGS.  9 A,  9 B, and/or  10   . 
     As further shown in  FIG.  18   , in some aspects, process  1800  may include transmitting DMRSs that are staggered across symbols, include cyclic shift hopping across symbols, are denser than one DMRS per four REs, or a combination thereof (block  1820 ). For example, the mobile station (e.g., using communication manager  140  and/or transmission component  2004 , depicted in  FIG.  20   ) may transmit DMRSs that are staggered across symbols, include cyclic shift hopping across symbols, are denser than one DMRS per four REs, or a combination thereof, as described in connection with  FIGS.  9 A,  9 B, and/or  10   . 
     Process  1800  may include additional aspects, such as any single aspect or any combination of aspects described below and/or in connection with one or more other processes described elsewhere herein. 
     In a first aspect, the DMRSs are hopped across symbols such that the DMRSs can be coherently combined across symbols to perform decoding. 
     In a second aspect, alone or in combination with the first aspect, the DMRSs are hopped across symbols according to a pattern such that a cyclic shift associated with the DMRSs can be determined based at least in part on the pattern. 
     Although  FIG.  18    shows example blocks of process  1800 , in some aspects, process  1800  may include additional blocks, fewer blocks, different blocks, or differently arranged blocks than those depicted in  FIG.  18   . Additionally, or alternatively, two or more of the blocks of process  1800  may be performed in parallel. 
       FIG.  19    is a diagram illustrating an example process  1900  performed, for example, by a mobile station, in accordance with the present disclosure. Example process  1900  is an example where the mobile station (e.g., UE  120  and/or apparatus  2000  of  FIG.  20   ) performs operations associated with configuring DMRSs on a sidelink. 
     As shown in  FIG.  19   , in some aspects, process  1900  may include determining a configuration associated with DMRSs on a sidelink channel that is associated with DMRSs that are staggered across symbols, include cyclic shift hopping across symbols, are denser than one DMRS per four REs, or a combination thereof (block  1910 ). For example, the mobile station (e.g., using communication manager  140  and/or determination component  2010 , depicted in  FIG.  20   ) may determine a configuration associated with DMRSs on a sidelink channel that is associated with DMRSs that are staggered across symbols, include cyclic shift hopping across symbols, are denser than one DMRS per four REs, or a combination thereof, as described in connection with  FIGS.  9 A,  9 B, and/or  10   . 
     As further shown in  FIG.  19   , in some aspects, process  1900  may include transmitting the configuration (block  1920 ). For example, the mobile station (e.g., using communication manager  140  and/or transmission component  2004 , depicted in  FIG.  20   ) may transmit the configuration, as described in connection with  FIGS.  9 A,  9 B, and/or  10   . 
     Process  1900  may include additional aspects, such as any single aspect or any combination of aspects described below and/or in connection with one or more other processes described elsewhere herein. 
     In a first aspect, the configuration indicates symbols to use for hopping such that DMRSs can be coherently combined across the symbols to perform decoding. 
     In a second aspect, alone or in combination with the first aspect, the configuration indicates patterns for hopping across symbols such that cyclic shifts associated with DMRSs can be determined based at least in part on the patterns. 
     Although  FIG.  19    shows example blocks of process  1900 , in some aspects, process  1900  may include additional blocks, fewer blocks, different blocks, or differently arranged blocks than those depicted in  FIG.  19   . Additionally, or alternatively, two or more of the blocks of process  1900  may be performed in parallel. 
       FIG.  20    is a diagram of an example apparatus  2000  for wireless communication. The apparatus  2000  may be a UE, or a UE may include the apparatus  2000 . In some aspects, the apparatus  2000  includes a reception component  2002  and a transmission component  2004 , which may be in communication with one another (for example, via one or more buses and/or one or more other components). As shown, the apparatus  2000  may communicate with another apparatus  2006  (such as a UE, a base station, or another wireless communication device) using the reception component  2002  and the transmission component  2004 . As further shown, the apparatus  2000  may include the communication manager  140 . The communication manager  140  may include one or more of a selection component  2008 , a determination component  2010 , or a computation component  2012 , among other examples. 
     In some aspects, the apparatus  2000  may be configured to perform one or more operations described herein in connection with  FIGS.  5 - 11   . Additionally, or alternatively, the apparatus  2000  may be configured to perform one or more processes described herein, such as process  1200  of  FIG.  12   , process  1300  of  FIG.  13   , process  1400  of  FIG.  14   , process  1500  of  FIG.  15   , process  1600  of  FIG.  16   , process  1700  of  FIG.  17   , process  1800  of  FIG.  18   , process  1900  of  FIG.  19   , or a combination thereof. In some aspects, the apparatus  2000  and/or one or more components shown in  FIG.  20    may include one or more components of the UE described in connection with  FIG.  2   . Additionally, or alternatively, one or more components shown in  FIG.  20    may be implemented within one or more components described in connection with  FIG.  2   . Additionally, or alternatively, one or more components of the set of components may be implemented at least in part as software stored in a memory. 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 a controller or a processor to perform the functions or operations of the component. 
     The reception component  2002  may receive communications, such as reference signals, control information, data communications, or a combination thereof, from the apparatus  2006 . The reception component  2002  may provide received communications to one or more other components of the apparatus  2000 . In some aspects, the reception component  2002  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 of the apparatus  2000 . In some aspects, the reception component  2002  may include one or more antennas, a modem, a demodulator, a MIMO detector, a receive processor, a controller/processor, a memory, or a combination thereof, of the UE described in connection with  FIG.  2   . 
     The transmission component  2004  may transmit communications, such as reference signals, control information, data communications, or a combination thereof, to the apparatus  2006 . In some aspects, one or more other components of the apparatus  2000  may generate communications and may provide the generated communications to the transmission component  2004  for transmission to the apparatus  2006 . In some aspects, the transmission component  2004  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  2006 . In some aspects, the transmission component  2004  may include one or more antennas, a modem, a modulator, a transmit MIMO processor, a transmit processor, a controller/processor, a memory, or a combination thereof, of the UE described in connection with  FIG.  2   . In some aspects, the transmission component  2004  may be co-located with the reception component  2002  in a transceiver. 
     In some aspects, the reception component  2002  may receive (e.g., from the apparatus  2006 ) an indication of a first set of resources for feedback and an indication of a second set of resources for feedback. The second set of resources are associated with a smaller quantity of cyclic shifts than the first set of resources. Accordingly, the transmission component  2004  may transmit (e.g., to the apparatus  2006 ) feedback on either the first set of resources or the second set of resources based at least in part on a distance associated with the feedback. 
     In some aspects, the reception component  2002  may receive SCI that indicates a zone identifier and a height (e.g., associated with the apparatus  2006 ). Accordingly, the selection component  2008  selects the first set of resources or the second set of resources based at least in part on the zone identifier and the height. The selection component  2008  may include a transmit MIMO processor, a transmit processor, a receive processor, a controller/processor, a memory, or a combination thereof, of the UE described in connection with  FIG.  2   . In some aspects, the reception component  2002  may receive a plurality of height intervals, such that the height indicated in the SCI includes an index associated with one of the plurality of height intervals. 
     Additionally, or alternatively, the reception component  2002  may receive SCI that indicates a three-dimensional zone identifier (e.g., associated with the apparatus  2006 ). Accordingly, the selection component  2008  selects the first set of resources or the second set of resources based at least in part on the three-dimensional zone identifier. 
     Additionally, or alternatively, the reception component  2002  may receive at least one DMRS (e.g., from the apparatus  2006 ). Accordingly, the selection component  2008  selects the first set of resources or the second set of resources based at least in part on the at least one DMRS. 
     In some aspects, the reception component  2002  may receive an indication of a distance threshold. Accordingly, the selection component  2008  selects the second set of resources is used when the distance satisfies the distance threshold. 
     As an alternative, the reception component  2002  may receive a plurality of distance thresholds, and the selection component  2008  may select one distance threshold of the plurality of distance thresholds based at least in part on a relative height (e.g., associated with the apparatus  2006 ). As an alternative, the reception component  2002  may receive an indication of the one distance threshold, of the plurality of distance thresholds, to use. 
     Additionally, or alternatively, the computation component  2012  may compute a timing advance associated with transmission of feedback. The computation component  2012  may include a transmit MIMO processor, a transmit processor, a receive processor, a controller/processor, a memory, or a combination thereof, of the UE described in connection with  FIG.  2   . Accordingly, the transmission component  2004  may transmit feedback that is shifted in time according to the timing advance. 
     In some aspects, the reception component  2002  may receive SCI that indicates a zone identifier and a height (e.g., associated with the apparatus  2006 ). Accordingly, the computation component  2012  shifts the feedback in time based at least in part on the zone identifier and the height. In some aspects, the reception component  2002  may receive a plurality of height intervals, such that the height indicated in the SCI includes an index associated with one of the plurality of height intervals. 
     Additionally, or alternatively, the reception component  2002  may receive SCI that indicates a three-dimensional zone identifier (e.g., associated with the apparatus  2006 ). Accordingly, the computation component  2012  shifts the feedback in time based at least in part on the three-dimensional zone identifier. 
     Additionally, or alternatively, the reception component  2002  may receive at least one DMRS (e.g., from the apparatus  2006 ). Accordingly, the computation component  2012  shifts the feedback in time based at least in part on the at least one DMRS. 
     In some aspects, the reception component  2002  may receive an indication of a distance threshold. Accordingly, the computation component  2012  shifts the feedback in time when the distance satisfies the distance threshold. 
     As an alternative, the reception component  2002  may receive a plurality of distance thresholds, and the selection component  2008  may select one distance threshold of the plurality of distance thresholds based at least in part on a relative height (e.g., associated with the apparatus  2006 ). As an alternative, the reception component  2002  may receive an indication of the one distance threshold, of the plurality of distance thresholds, to use. 
     Additionally, or alternatively, the reception component  2002  may receive (e.g., from the apparatus  2006 ) an indication of a first set of resources and an indication of a second set of resources, where the second set of resources are associated with a smaller quantity of cyclic shifts in DMRSs than the first set of resources. Accordingly, the transmission component  2004  may transmit (e.g., to the apparatus  2006 ) DMRSs on either the first set of resources or the second set of resources based at least in part on a distance associated with the DMRSs. 
     As an alternative, the reception component  2002  may receive (e.g., from the apparatus  2006 ) a configuration associated with DMRSs on a sidelink channel. Accordingly, transmission component  2004  may transmit (e.g., to the apparatus  2006 ) DMRSs that are staggered across symbols, include cyclic shift hopping across symbols, are denser than one DMRS per four REs, or a combination thereof. 
     When the apparatus  2000  is a transmitting mobile station rather than receiving mobile station, the determination component  2010  may determine a first set of resources for feedback and a second set of resources for feedback. The second set of resources are associated with a smaller quantity of cyclic shifts than the first set of resources. The determination component  2010  may include a transmit MIMO processor, a transmit processor, a receive processor, a controller/processor, a memory, or a combination thereof, of the UE described in connection with  FIG.  2   . Accordingly, the transmission component  2004  may transmit (e.g., to the apparatus  2006 ) an indication of the first set of resources and an indication of the second set of resources. 
     Additionally, or alternatively, the transmission component  2004  may transmit information associated with at least one distance threshold (e.g., to the apparatus  2006 ) for long-range sidelink feedback. Additionally, the transmission component  2004  may transmit an indication associated with a plurality of sets of MCRs (e.g., to the apparatus  2006 ). 
     Additionally, or alternatively, the determination component  2010  may determine a first set of resources and a second set of resources, where the second set of resources are associated with a smaller quantity of cyclic shifts in DMRSs than the first set of resources. Accordingly, the transmission component  2004  may transmit (e.g., to the apparatus  2006 ) an indication of the first set of resources and an indication of the second set of resources. 
     As an alternative, the determination component  2010  may determine a configuration associated with DMRSs on a sidelink channel, where the configuration is associated with DMRSs that are staggered across symbols, include cyclic shift hopping across symbols, are denser than one DMRS per four REs, or a combination thereof. Accordingly, the transmission component  2004  may transmit (e.g., to the apparatus  2006 ) the configuration. 
     The number and arrangement of components shown in  FIG.  20    are provided as an example. In practice, there may be additional components, fewer components, different components, or differently arranged components than those shown in  FIG.  20   . Furthermore, two or more components shown in  FIG.  20    may be implemented within a single component, or a single component shown in  FIG.  20    may be implemented as multiple, distributed components. Additionally, or alternatively, a set of (one or more) components shown in  FIG.  20    may perform one or more functions described as being performed by another set of components shown in  FIG.  20   . 
     The following provides an overview of some Aspects of the present disclosure: 
     Aspect 1: A method of wireless communication performed by a mobile station, comprising: receiving an indication of a first set of resources for feedback and an indication of a second set of resources for feedback, wherein the second set of resources are associated with a smaller quantity of cyclic shifts than the first set of resources; and transmitting feedback on either the first set of resources or the second set of resources based at least in part on a distance associated with the feedback. 
     Aspect 2: The method of Aspect 1, wherein the indication of the second set of resources comprises a bitmap. 
     Aspect 3: The method of any of Aspects 1 through 2, wherein the second set of resources is associated with a different period than a period associated with the first set of resources. 
     Aspect 4: The method of any of Aspects 1 through 3, further comprising: receiving sidelink control information (SCI) that indicates a zone identifier and a height associated with a receiver for the feedback, wherein the distance associated with feedback is based at least in part on the zone identifier and the height. 
     Aspect 5: The method of Aspect 4, further comprising: receiving a plurality of height intervals, wherein the height indicated in the SCI includes an index associated with one of the plurality of height intervals. 
     Aspect 6: The method of any of Aspects 1 through 5, further comprising: receiving sidelink control information (SCI) that indicates a three-dimensional zone identifier associated with a receiver for the feedback, wherein the distance associated with feedback is based at least in part on the three-dimensional zone identifier. 
     Aspect 7: The method of any of Aspects 1 through 6, further comprising: receiving at least one demodulation reference signal (DMRS) from a receiver for the feedback, wherein the distance associated with feedback is determined based at least in part on the at least one DMRS. 
     Aspect 8: The method of any of Aspects 1 through 7, further comprising: receiving an indication of a distance threshold, wherein the second set of resources is used when the distance satisfies the distance threshold. 
     Aspect 9: The method of any of Aspects 1 through 7, further comprising: receiving a plurality of distance thresholds; and selecting one distance threshold of the plurality of distance thresholds based at least in part on a relative height associated with a receiver for the feedback, wherein the second set of resources is used when the distance satisfies the distance threshold. 
     Aspect 10: The method of Aspect 9, further comprising: receiving, from the receiver for the feedback, an indication of the one distance threshold, of the plurality of distance thresholds, to use. 
     Aspect 11: The method of any of Aspects 1 through 10, wherein the feedback is transmitted based at least in part on a minimum communication range (MCR) associated with the feedback, and the method further comprises: receiving a plurality of MCRs; and selecting the MCR from the plurality of MCRs based at least in part on a relative height associated with a receiver for the feedback. 
     Aspect 12: A method of wireless communication performed by a mobile station, comprising: determining a first set of resources for feedback and a second set of resources for feedback, wherein the second set of resources are associated with a smaller quantity of cyclic shifts than the first set of resources; and transmitting an indication of the first set of resources and an indication of the second set of resources. 
     Aspect 13: The method of Aspect 12, wherein the indication of the second set of resources comprises a bitmap. 
     Aspect 14: The method of any of Aspects 12 through 13, wherein the second set of resources is associated with a different period than a period associated with the first set of resources. 
     Aspect 15: A method of wireless communication performed by a mobile station, comprising: computing a timing advance associated with transmission of feedback; and transmitting feedback that is shifted in time according to the timing advance. 
     Aspect 16: The method of Aspect 15, further comprising: receiving sidelink control information (SCI) that indicates a zone identifier and a height associated with a receiver for the feedback, wherein the timing advance associated with the transmission of the feedback is based at least in part on the zone identifier and the height. 
     Aspect 17: The method of Aspect 16, further comprising: receiving a plurality of height intervals, wherein the height indicated in the SCI includes an index associated with one of the plurality of height intervals. 
     Aspect 18: The method of any of Aspects 15 through 17, further comprising: receiving sidelink control information (SCI) that indicates a three-dimensional zone identifier associated with a receiver for the feedback, wherein the timing advance associated with the transmission of the feedback is based at least in part on the three-dimensional zone identifier. 
     Aspect 19: The method of any of Aspects 15 through 18, further comprising: receiving at least one demodulation reference signal (DMRS) from a receiver for the feedback, wherein the timing advance associated with the transmission of the feedback is based at least in part on a distance associated with the feedback and determined based at least in part on the at least one DMRS. 
     Aspect 20: The method of any of Aspects 15 through 19, further comprising: receiving an indication of a distance threshold, wherein the timing advance associated with the transmission of the feedback is applied when a distance associated with the feedback satisfies the distance threshold. 
     Aspect 21: The method of any of Aspects 15 through 19, further comprising: receiving a plurality of distance thresholds; and selecting one distance threshold of the plurality of distance thresholds based at least in part on a relative height associated with a receiver for the feedback, the timing advance associated with the transmission of the feedback is applied when a distance associated with the feedback satisfies the distance threshold. 
     Aspect 22: The method of Aspect 21, further comprising: receiving, from the receiver for the feedback, an indication of the one distance threshold, of the plurality of distance thresholds, to use. 
     Aspect 23: The method of any of Aspects 15 through 22, wherein the feedback is transmitted based at least in part on a minimum communication range (MCR) associated with the feedback, and the method further comprises: receiving a plurality of MCRs; and selecting the MCR from the plurality of MCRs based at least in part on a relative height associated with a receiver for the feedback. 
     Aspect 24: A method of wireless communication performed by a transmitting mobile station, comprising: transmitting information associated with at least one distance threshold, to a receiving mobile station, for long-range sidelink feedback; and transmitting an indication associated with a plurality of sets of minimum communication ranges (MCRs) to the receiving mobile station. 
     Aspect 25: The method of Aspect 24, wherein the at least one distance threshold includes a plurality of distance thresholds, and each distance threshold, of the plurality of distance thresholds, is associated with a corresponding height, and the information indicates a height associated with the transmitting mobile station. 
     Aspect 26: The method of any of Aspects 24 through 25, wherein each set of MCRs, of the plurality of sets of MCRs, is associated with a corresponding height. 
     Aspect 27: A method of wireless communication performed by a mobile station, comprising: receiving an indication of a first set of resources and an indication of a second set of resources, wherein the second set of resources are associated with a smaller quantity of cyclic shifts in demodulation reference signals (DMRSs) than the first set of resources; and transmitting DMRSs on either the first set of resources or the second set of resources based at least in part on a distance associated with the DMRSs. 
     Aspect 28: The method of Aspect 27, wherein the first set of resources includes a first resource pool, and the second set of resources includes a second resource pool. 
     Aspect 29: The method of Aspect 27, wherein the first set of resources includes a first subchannel, and the second set of resources includes a second subchannel. 
     Aspect 30: A method of wireless communication performed by a mobile station, comprising: determining a first set of resources and a second set of resources, wherein the second set of resources are associated with a smaller quantity of cyclic shifts in demodulation reference signals (DMRSs) than the first set of resources; and transmitting an indication of the first set of resources and an indication of the second set of resources. 
     Aspect 31: The method of Aspect 30, wherein the first set of resources includes a first resource pool, and the second set of resources includes a second resource pool. 
     Aspect 32: The method of Aspect 30, wherein the first set of resources includes a first subchannel, and the second set of resources includes a second subchannel. 
     Aspect 33: A method of wireless communication performed by a mobile station, comprising: receiving a configuration associated with demodulation reference signals (DMRSs) on a sidelink channel; and transmitting DMRSs that are staggered across symbols, include cyclic shift hopping across symbols, are denser than one DMRS per four resource elements (REs), or a combination thereof. 
     Aspect 34: The method of Aspect 33, wherein the DMRSs are hopped across symbols such that the DMRSs can be coherently combined across symbols to perform decoding. 
     Aspect 35: The method of Aspect 33, wherein the DMRSs are hopped across symbols according to a pattern such that a cyclic shift associated with the DMRSs can be determined based at least in part on the pattern. 
     Aspect 36: A method of wireless communication performed by a mobile station, comprising: determining a configuration associated with demodulation reference signals (DMRSs) on a sidelink channel, wherein the configuration is associated with DMRSs that are staggered across symbols, include cyclic shift hopping across symbols, are denser than one DMRS per four resource elements (REs), or a combination thereof; and transmitting the configuration. 
     Aspect 37: The method of Aspect 36, wherein the configuration indicates symbols to use for hopping such that DMRSs can be coherently combined across the symbols to perform decoding. 
     Aspect 38: The method of Aspect 36, wherein the configuration indicates patterns for hopping across symbols such that cyclic shifts associated with DMRSs can be determined based at least in part on the patterns. 
     Aspect 39: An apparatus for wireless communication at a device, comprising a processor; memory coupled with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform the method of one or more of Aspects 1-11. 
     Aspect 40: A device for wireless communication, comprising a memory and one or more processors coupled to the memory, the one or more processors configured to perform the method of one or more of Aspects 1-11. 
     Aspect 41: An apparatus for wireless communication, comprising at least one means for performing the method of one or more of Aspects 1-11. 
     Aspect 42: A non-transitory computer-readable medium storing code for wireless communication, the code comprising instructions executable by a processor to perform the method of one or more of Aspects 1-11. 
     Aspect 43: 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 44: An apparatus for wireless communication at a device, comprising a processor; memory coupled with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform the method of one or more of Aspects 12-14. 
     Aspect 45: A device for wireless communication, comprising a memory and one or more processors coupled to the memory, the one or more processors configured to perform the method of one or more of Aspects 12-14. 
     Aspect 46: An apparatus for wireless communication, comprising at least one means for performing the method of one or more of Aspects 12-14. 
     Aspect 47: A non-transitory computer-readable medium storing code for wireless communication, the code comprising instructions executable by a processor to perform the method of one or more of Aspects 12-14. 
     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 12-14. 
     Aspect 49: An apparatus for wireless communication at a device, comprising a processor; memory coupled with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform the method of one or more of Aspects 15-23. 
     Aspect 50: A device for wireless communication, comprising a memory and one or more processors coupled to the memory, the one or more processors configured to perform the method of one or more of Aspects 15-23. 
     Aspect 51: An apparatus for wireless communication, comprising at least one means for performing the method of one or more of Aspects 15-23. 
     Aspect 52: A non-transitory computer-readable medium storing code for wireless communication, the code comprising instructions executable by a processor to perform the method of one or more of Aspects 15-23. 
     Aspect 53: 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 15-23. 
     Aspect 54: An apparatus for wireless communication at a device, comprising a processor; memory coupled with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform the method of one or more of Aspects 24-26. 
     Aspect 55: A device for wireless communication, comprising a memory and one or more processors coupled to the memory, the one or more processors configured to perform the method of one or more of Aspects 24-26. 
     Aspect 56: An apparatus for wireless communication, comprising at least one means for performing the method of one or more of Aspects 24-26. 
     Aspect 57: A non-transitory computer-readable medium storing code for wireless communication, the code comprising instructions executable by a processor to perform the method of one or more of Aspects 24-26. 
     Aspect 58: 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 24-26. 
     Aspect 59: An apparatus for wireless communication at a device, comprising a processor; memory coupled with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform the method of one or more of Aspects 27-29. 
     Aspect 60: A device for wireless communication, comprising a memory and one or more processors coupled to the memory, the one or more processors configured to perform the method of one or more of Aspects 27-29. 
     Aspect 61: An apparatus for wireless communication, comprising at least one means for performing the method of one or more of Aspects 27-29. 
     Aspect 62: A non-transitory computer-readable medium storing code for wireless communication, the code comprising instructions executable by a processor to perform the method of one or more of Aspects 27-29. 
     Aspect 63: 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 27-29. 
     Aspect 64: An apparatus for wireless communication at a device, comprising a processor; memory coupled with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform the method of one or more of Aspects 30-32. 
     Aspect 65: A device for wireless communication, comprising a memory and one or more processors coupled to the memory, the one or more processors configured to perform the method of one or more of Aspects 30-32. 
     Aspect 66: An apparatus for wireless communication, comprising at least one means for performing the method of one or more of Aspects 30-32. 
     Aspect 67: A non-transitory computer-readable medium storing code for wireless communication, the code comprising instructions executable by a processor to perform the method of one or more of Aspects 30-32. 
     Aspect 68: 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 30-32. 
     Aspect 69: An apparatus for wireless communication at a device, comprising a processor; memory coupled with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform the method of one or more of Aspects 33-35. 
     Aspect 70: A device for wireless communication, comprising a memory and one or more processors coupled to the memory, the one or more processors configured to perform the method of one or more of Aspects 33-35. 
     Aspect 71: An apparatus for wireless communication, comprising at least one means for performing the method of one or more of Aspects 33-35. 
     Aspect 72: A non-transitory computer-readable medium storing code for wireless communication, the code comprising instructions executable by a processor to perform the method of one or more of Aspects 33-35. 
     Aspect 73: 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 33-35. 
     Aspect 74: An apparatus for wireless communication at a device, comprising a processor; memory coupled with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform the method of one or more of Aspects 36-38. 
     Aspect 75: A device for wireless communication, comprising a memory and one or more processors coupled to the memory, the one or more processors configured to perform the method of one or more of Aspects 36-38. 
     Aspect 76: An apparatus for wireless communication, comprising at least one means for performing the method of one or more of Aspects 36-38. 
     Aspect 77: A non-transitory computer-readable medium storing code for wireless communication, the code comprising instructions executable by a processor to perform the method of one or more of Aspects 36-38. 
     Aspect 78: 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 36-38. 
     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 and/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, and/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 and/or a combination of hardware and software. It will be apparent that systems and/or methods described herein may be implemented in different forms of hardware and/or a combination of hardware and software. The actual specialized control hardware or software code used to implement these systems and/or methods is not limiting of the aspects. Thus, the operation and behavior of the systems and/or methods are described herein without reference to specific software code, since those skilled in the art will understand that software and hardware can be designed to implement the systems and/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, not equal to the threshold, or the like. 
     Even though particular combinations of features are recited in the claims and/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 and/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 (e.g., 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,” or the like are intended to be open-ended terms that do not limit an element that they modify (e.g., an element “having” A may also have B). Further, the phrase “based on” is intended to mean “based, at least in part, on” unless explicitly stated otherwise. 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 (e.g., if used in combination with “either” or “only one of”).