Techniques for resource selection for sidelink communications in unlicensed radio frequency spectrum bands

Abstract

Methods, systems, and devices for wireless communication are described. A user equipment (UE) can determine resource selection priorities associated with available resources for sidelink signaling in an unlicensed radio frequency spectrum band, which can be determined based on resource reservation information for the available resources, time domain locations of the available resources, or both. For example, in resource selection, a first resource of the available resources can be associated with a higher priority than a second resource of the available resources. The UE can select one or more resources from the available resources for the sidelink signaling based on the resource selection priorities associated with the available resources. The UE can transmit the sidelink signaling over the unlicensed radio frequency spectrum band using the one or more selected resources.

Description

[0001] Cross-referencing

[0002] This patent application claims priority to Greek Provisional Patent No. 20200100353, filed on June 22, 2020, entitled “TECHNIQUES FORRESOURCE SELECTION FOR SIDELINK COMMUNICATION IN UNLICENSED RADIO FREQUENCYSPECTRUM BAND”, which has been assigned to the assignee of this application and whose entire contents are expressly incorporated herein by reference. Technical Field

[0003] The following generally relates to wireless communications, and more specifically to techniques for resource selection for sidelink communications in unlicensed radio spectrum bands. Background Technology

[0004] Wireless communication systems are widely deployed to provide various types of communication content, such as voice, video, packet data, messaging, and broadcasting. These systems can support communication with multiple users by sharing available system resources (e.g., time, frequency, and power). Examples of such multiple access systems include fourth-generation (4G) systems such as Long Term Evolution (LTE), LTE-A Advanced (LTE-A), or LTE-A Pro systems, and fifth-generation (5G) systems, which may be referred to as New Radio (NR) systems. These systems can employ technologies such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), or Discrete Fourier Transform Extended Orthogonal Frequency Division Multiplexing (DFT-S-OFDM). A wireless multiple access communication system may include one or more base stations or one or more network access nodes, each of which simultaneously supports communication from multiple communication devices, which may also be referred to as User Equipment (UE).

[0005] In some wireless communication systems, the UE can select the resource allocation for communication (such as sidelink communication). In some cases, the sidelink channel used for sidelink communication can be in an unlicensed radio spectrum band. Some techniques for selecting resources in an unlicensed radio spectrum band for sidelink communication can be improved. Summary of the Invention

[0006] The described technology relates to improved methods, systems, devices, and apparatuses for resource selection for sidelink communication in unlicensed radio spectrum bands. Typically, the described technology provides prioritizing resources when selecting resources for sidelink communication to avoid transmission gaps. A user equipment (UE) can perform channel sensing and select resources for sidelink transmission on a sidelink channel in an unlicensed radio spectrum band. The UE can identify which resources are available for sidelink transmission within a resource selection window and prioritize some resources to prevent transmission gaps during the Channel Occupancy Time (COT) acquired for sidelink communication. If a transmission gap greater than a duration threshold exists within the COT, the UE communicating on the sidelink channel may lose access to the channel medium, or fail to acquire the channel medium in the remaining time slots of the COT, and the UE may need to perform channel sensing to regain access to the channel, for example, based on a channel access procedure with random back-off within the contention window. This can increase latency and overhead in channel access for sidelink UEs and degrade the performance of other radio devices sharing the medium. In some cases, the UE can prioritize available resources in time slots that have not yet been at least partially reserved by another radio device. For example, if available resources exist in completely unreserved time slots, the UE can prioritize these available resources when selecting resources for sidelink transmission. Alternatively, the UE can prioritize available resources in earlier time slots within the COT or resource selection window. For example, the UE can identify earlier high-priority windows within the resource selection window, and available resources within high-priority windows can be selected with priority over other resources (e.g., later resources within the resource selection window).

[0007] A method for wireless communication at a UE is described. The method may include determining a resource selection priority associated with available resources for sidelink signaling in an unlicensed radio spectrum band, the resource selection priority being determined based on resource reservation information of the available resources, the time-domain location of the available resources, or both, wherein in the resource selection, a first resource among the available resources is associated with a higher priority than a second resource among the available resources; selecting one or more resources for sidelink signaling from the available resources based on the resource selection priority associated with the available resources; and transmitting sidelink signaling in the unlicensed radio spectrum band using the one or more selected resources.

[0008] An apparatus for wireless communication at a UE is described. The apparatus may include a processor, a memory coupled to the processor, and instructions stored in the memory. The instructions, executable by the processor, enable the apparatus to determine a resource selection priority associated with available resources for sidelink signaling in an unlicensed radio spectrum band. This resource selection priority may be determined based on resource reservation information of the available resources, the time-domain location of the available resources, or both, wherein in the resource selection, a first resource among the available resources is associated with a higher priority than a second resource among the available resources; select one or more resources for sidelink signaling from the available resources based on the resource selection priority associated with the available resources; and transmit sidelink signaling in the unlicensed radio spectrum band using the one or more selected resources.

[0009] Another apparatus for wireless communication at a UE is described. The apparatus may include components for the following steps: determining a resource selection priority associated with available resources for sidelink signaling in an unlicensed radio spectrum band, the resource selection priority being determined based on resource reservation information of the available resources, the time-domain location of the available resources, or both, wherein in the resource selection, a first resource among the available resources is associated with a higher priority than a second resource among the available resources; selecting one or more resources for sidelink signaling from the available resources based on the resource selection priority associated with the available resources; and transmitting the sidelink signaling in the unlicensed radio spectrum band using the one or more selected resources.

[0010] A non-transitory computer-readable medium is described, storing code for wireless communication at a UE. The code may include instructions executable by a processor to perform the following steps: determining a resource selection priority associated with available resources for sidelink signaling in an unlicensed radio spectrum band, the resource selection priority being determined based on resource reservation information of the available resources, the time-domain location of the available resources, or both, wherein in the resource selection, a first resource among the available resources is associated with a higher priority than a second resource among the available resources; selecting one or more resources from the available resources for sidelink signaling based on the resource selection priority associated with the available resources; and transmitting sidelink signaling in the unlicensed radio spectrum band using the one or more selected resources.

[0011] In some examples of the methods, apparatuses, and nontransitory computer-readable media described herein, determining resource selection priority may include determining that a first time slot including a first resource may not be reserved for communication on an unlicensed radio spectrum band, wherein the first resource may be associated with a higher priority based on the unreservation of the time slot; and determining that a second time slot including a second resource may be at least partially reserved by other devices for communication on an unlicensed radio spectrum band.

[0012] In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, selecting one or more resources may include operations, features, components, or instructions for randomly selecting one or more resources from those associated with a higher priority.

[0013] In some examples of the methods, apparatuses and non-transitory computer-readable media described herein, selecting one or more resources may include operations, features, components or instructions for selecting one or more resources for sidelink signaling from available resources, wherein resources associated with higher priority may have a higher probability of being selected.

[0014] In some examples of the methods, apparatuses and nontransitory computer-readable media described herein, selecting one or more resources may include determining a first selection probability of a resource associated with a higher priority, determining a second selection probability of a resource associated with a lower priority, wherein the first selection probability may be greater than the second selection probability, and operations, features, components or instructions for selecting one or more resources from available resources based on the first selection probability and the second selection probability.

[0015] In some examples of the methods, apparatuses and non-transitory computer-readable media described herein, determining resource selection priority may include identifying resource selection windows and identifying operations, features, components or instructions of higher priority windows within the resource selection window, wherein available resources span the resource selection window.

[0016] In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, a high-priority window corresponds to an earlier resource in a resource selection window.

[0017] In some examples of the methods, apparatuses and nontransitory computer-readable media described herein, selecting one or more resources may include determining a first selection probability of a resource associated with a higher priority in a high priority window, determining a second selection of a resource associated with a lower priority, wherein the first selection probability may be greater than the second selection probability, and operations, features, components or instructions for selecting one or more resources from available resources based on the first selection probability and the second selection probability.

[0018] In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, selecting one or more resources may include operations, features, components, or instructions for selecting one or more resources from resources in a high-priority window.

[0019] In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, the selection may be random.

[0020] In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, high-priority windows can be based on the processing speed of the UE.

[0021] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include methods for determining that time slots including resources associated with higher priority may not be reserved by other wireless devices for operation, features, components, or instructions in unlicensed radio spectrum bands.

[0022] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for determining a resource selection window corresponding to available resources, wherein the resource selection window may be determined based on channel occupancy time configured by the UE, base station, another UE, roadside unit, or any combination thereof.

[0023] In some examples of the methods, apparatuses and nontransitory computer-readable media described herein, resource selection priorities include at least a first priority and a second priority, wherein a resource may be associated with a first priority or a second priority based on whether a time slot including the resource can be at least partially reserved by another device, the time position of the resource within a resource selection window, or a combination thereof.

[0024] In some examples of the methods, apparatuses and non-transitory computer-readable media described herein, a resource may be associated with a first priority if the time slot including the resource may not be at least partially reserved by another device, or if the resource is available earlier in the resource selection window, or both.

[0025] In some examples of the methods, apparatuses and nontransitory computer-readable media described herein, a resource may be associated with a second priority if the time slot including the resource can be at least partially reserved by another device, or if the resource can be in a later position within a resource selection window, or both.

[0026] In some examples of the methods, apparatuses and non-transitory computer-readable media described herein, the sidelink signaling includes a sidelink transmission and one or more retransmissions of the sidelink transmission, wherein the one or more resources can be selected for the sidelink transmission and the one or more retransmissions of the sidelink transmission.

[0027] In some examples of the methods, apparatuses and non-transitory computer-readable media described herein, a first set of resources for sidelink transmissions may be selected based on an earlier high-priority window within a resource selection window, and a second set of resources for one or more retransmissions of sidelink transmissions may be selected based on time slots that include a second set of resources not at least partially reserved by other wireless devices for unlicensed radio spectrum bands.

[0028] In some examples of the methods, apparatuses and non-transitory computer-readable media described herein, available resources may be available within a channel occupancy period configured by a base station, UE or another node.

[0029] In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, the available resources span at least the channel occupancy time configured by the base station, UE, or another node. Attached Figure Description

[0030] Figure 1 An example of a wireless communication system is illustrated, which supports a technique for resource selection for sidelink communication in an unlicensed radio spectrum band, according to aspects of this disclosure.

[0031] Figure 2 An example of a wireless communication system is illustrated, which supports a technique for resource selection for sidelink communication in an unlicensed radio spectrum band, according to aspects of this disclosure.

[0032] Figure 3 An example of an autonomous resource selection scheme is illustrated, which supports a technology for resource selection for sidelink communication in an unlicensed radio spectrum band, according to aspects of this disclosure.

[0033] Figure 4 An example of a resource selection scheme is illustrated, which supports a technology for resource selection for sidelink communication in an unlicensed radio spectrum band, according to aspects of this disclosure.

[0034] Figure 5 An example of a process flow illustrating a technique for resource selection for sidelink communication in an unlicensed radio spectrum band, according to aspects of this disclosure.

[0035] Figure 6 and Figure 7 A block diagram of an apparatus for resource selection for sidelink communication in an unlicensed radio spectrum band is shown, according to aspects of this disclosure.

[0036] Figure 8 A block diagram of a communication manager supporting technology for resource selection for sidelink communication in unlicensed radio spectrum bands, according to aspects of this disclosure, is shown.

[0037] Figure 9 A diagram of a system including an apparatus for supporting technology for sidelink communication in an unlicensed radio spectrum band is shown, according to aspects of this disclosure.

[0038] Figures 10 to 13A flowchart illustrating a technique for resource selection for sidelink communication in an unlicensed radio spectrum band is shown, according to aspects of this disclosure. Detailed Implementation

[0039] Some wireless communication systems can support direct communication between devices. For example, User Equipment (UE) can communicate on a sidelink. In some of these systems, the UE can autonomously select resources for communication on the sidelink. For example, the UE can perform sensing to detect resource availability and select from candidate resources for sidelink transmission. By decoding signals from past sensing windows, the UE can determine which resources are available in the selection window (e.g., a future window), such as resources not yet reserved by other devices. The UE can determine available resources in the selection window based on decoding Sidelink Control Information (SCI), measuring reference signals transmitted in the sensing window, or both, which can indicate resource reservation in the resource selection window. In some cases, the UE can reserve a first resource for sidelink transmission and reserve multiple additional resources in future time slots for other transmissions or retransmissions.

[0040] Some wireless communication systems can support sidelink communication and unlicensed radio spectrum communication. In some cases, unlicensed radio spectrum bands can be shared by multiple technologies (e.g., Wi-Fi, New Radio (NR)), and devices can operate to use this unlicensed radio spectrum band based on certain conditions. For example, a device can perform a Listen-Before-Speak (LBT) type channel access procedure to sense whether the channel is idle (e.g., not used by other devices) to acquire the channel medium and communicate. In some cases, if a transmission gap greater than a duration threshold (e.g., 16 microseconds, 25 microseconds) occurs during channel occupancy after acquiring the channel medium, the device sharing the channel occupancy may not assume that the medium is still available after the gap. Therefore, if a transmission gap occurs during shared channel occupancy after acquiring the channel medium, the device sharing the channel occupancy may lose the channel medium. If the device loses the channel medium, it can perform another LBT type channel access procedure (e.g., Category 4 LBT or Type 1 channel access as defined in 3GPP) before resuming transmission, which increases channel access latency and overhead and thus degrades system performance.

[0041] In some cases, to support sidelink communication using unlicensed spectrum, UEs can share a set of resources. For example, devices such as base stations, network nodes, or UEs can initiate or configure a Channel Occupancy Time (COT) for the channel medium, and UEs can share unlicensed radio spectrum bands during the COT. In some cases, UEs can use autonomous scheduling techniques to identify available resources and randomly select resources for sidelink transmissions and retransmissions. However, implementations of resource scheduling based on existing techniques may result in gaps in autonomously scheduled resources (e.g., within the COT). If the gap is greater than a duration threshold (e.g., 16 µs or 25 µs), UEs sharing the channel occupancy may lose the medium. For example, based on random resource selection, some time slots within the resource selection window or COT may not have resources selected or reserved by UEs sharing the channel occupancy, and therefore these time slots will have no sidelink transmissions from UEs, creating gaps in the shared channel occupancy. UEs can perform another LBT (e.g., as defined in 3GPP Category 4 LBT or Type 1 Channel Access) and determine that the medium is available before resuming transmission after the transmission gap. This could increase latency and reduce the reliability of sidelink communications on unlicensed radio spectrum.

[0042] UEs implementing the techniques described herein can allocate resources to reduce the probability of gaps in sidelink transmissions within a COT. These techniques can increase the probability that the UE and other UEs sharing a COT can retain the channel medium after acquiring it, and avoid performing additional LBTs to reacquire the medium. The UE can identify available resources within a resource selection window or shared channel occupancy and determine different priorities for available resources within the resource selection window or channel occupancy. In some cases, resources in time slots that currently have no resources reserved by other devices or UEs can be prioritized for selection. For example, by selecting resources in time slots that have not yet been at least partially used by other devices, the UE can reduce the number of transmission gaps during the COT by reducing the number of time slots without transmissions. In some examples, the UE can prioritize resources in earlier time slots within the resource selection window. Selecting earlier resources in the resource selection window can increase the likelihood that the UE can successfully acquire the channel medium and send sidelink signaling. One or more of these techniques can be applied to reserve resources for sidelink communication. For example, the UE can prioritize earlier resources for current transmissions and prioritize resources in time slots with unreserved resources for future retransmissions. When performing resource selection, a resource in the resource selection window or channel occupancy can be identified as available if no other device has already reserved the resource, if the resource has been reserved but the Received Reference Signal Power (RSRP) from the UE reserving the resource is less than the RSRP threshold, if the resource has been reserved but the UE reserving the resource has a lower service priority, or any combination thereof. Therefore, a time slot in which no resource is currently being reserved by another UE is a time slot in which all resources are identified as available.

[0043] The aspects of this disclosure are initially described in the context of wireless communication systems. These aspects are further illustrated and described with reference to apparatus diagrams, system diagrams, and flowcharts relating to techniques for resource selection for sidelink communication in unlicensed radio spectrum bands.

[0044] Figure 1An example of a wireless communication system 100 supporting technology for resource selection for sidelink communication in unlicensed radio spectrum bands, according to aspects of this disclosure, is illustrated. The wireless communication system 100 may include one or more base stations 105, one or more UEs 115, and a core network 130. In some examples, the wireless communication system 100 may be a Long Term Evolution (LTE) network, an Advanced LTE (LTE-A) network, an LTE-A Pro network, or a New Radio (NR) network. In some examples, the wireless communication system 100 may support enhanced broadband communication, ultra-reliable (e.g., mission-critical) communication, low-latency communication, communication with low-cost and low-complexity devices, or any combination thereof.

[0045] Base stations 105 can be distributed throughout a geographical area to form a wireless communication system 100, and can be devices of different forms or with different capabilities. Base stations 105 and UE 115 can communicate wirelessly via one or more communication links 125. Each base station 105 can provide a coverage area 110 over which UE 115 and base station 105 can establish one or more communication links 125. Coverage area 110 can be an example of a geographical area over which base station 105 and UE 115 can support signal communication according to one or more radio access technologies.

[0046] UE 115 can be distributed throughout the entire coverage area 110 of the wireless communication system 100, and each UE 115 can be stationary or mobile at different times, or both. UE 115 can be different types of devices or devices with different capabilities. Figure 1 The diagrams illustrate some example UE 115s. The UE 115 described herein can communicate with various types of devices, such as other UE 115s, base station 105, or network equipment (e.g., core network nodes, relay equipment, integrated access and backhaul (IAB) nodes, or other network equipment), such as... Figure 1 As shown.

[0047] Base station 105 may communicate with core network 130, communicate with each other, or both. For example, base station 105 may interface with core network 130 via one or more backhaul links 120 (e.g., via S1, N2, N3, or other interfaces). Base station 105 may communicate with each other directly (e.g., directly between base stations 105) or indirectly (e.g., via core network 130) on backhaul links 120 (e.g., via X2, Xn, or other interfaces), or both. In some examples, backhaul link 120 may be or may include one or more radio links.

[0048] One or more base stations 105 described herein may include, or may be referred to by those skilled in the art as, base station transceiver, radio base station, access point, radio transceiver, NodeB, eNodeB (eNB), next-generation NodeB or gigabit NodeB (any of which may be referred to as gNB), home NodeB, home eNodeB or other suitable terms.

[0049] UE 115 may include or be referred to as a mobile device, wireless device, remote device, handheld device, or subscriber device, or any other suitable term, wherein "device" may also be referred to as a cell, station, terminal, or client, etc. UE 115 may also include or be referred to as a personal electronic device, such as a cellular phone, personal digital assistant (PDA), tablet computer, laptop computer, or personal computer. In some examples, UE 115 may include or be referred to as a wireless local loop (WLL) station, Internet of Things (IoT) device, Internet of Everything (IoE) device, or machine-type communication (MTC) device, which may be implemented in various objects such as appliances or vehicles, meters, etc.

[0050] The UE 115 described in this document can communicate with various types of devices, such as other UEs 115 that sometimes act as repeaters, as well as base station 105 and network devices, including macro eNBs or gNBs, small cell eNBs or gNBs, or relay base stations, etc. Figure 1 As shown.

[0051] UE 115 and base station 105 can communicate wirelessly with each other via one or more communication links 125 on one or more carriers. The term "carrier" can refer to a collection of radio spectrum resources having a defined physical layer structure for supporting communication link 125. For example, a carrier for communication link 125 may include a portion of the radio spectrum band (e.g., a bandwidth portion (BWP)) according to one or more physical layer channels operating for a given radio access technology (e.g., LTE, LTE-A, LTE-A Pro, NR). Each physical layer channel may carry acquisition signaling (e.g., synchronization signals, system information), control signaling coordinating carrier operation, user data, or other signaling. Wireless communication system 100 can use carrier aggregation or multi-carrier operation to support communication with UE 115. UE 115 can be configured with multiple downlink component carriers and one or more uplink component carriers according to a carrier aggregation configuration. Carrier aggregation can be used with frequency division duplex (FDD) and time division duplex (TDD) component carriers.

[0052] In some examples (e.g., in a carrier aggregation configuration), a carrier may also have acquisition or control signaling to coordinate the operation of other carriers. A carrier may be associated with a frequency channel (e.g., an Evolved Universal Mobile Telecommunications System Terrestrial Radio Access (E-UTRA) Absolute Radio Frequency Channel Number (EARFCN)) and can be located according to a channel grid for discovery by UE 115. A carrier may operate in standalone mode, where UE 115 can perform initial acquisition and connection via that carrier, or the carrier may operate in non-standalone mode, where different carriers (e.g., the same or different radio access technologies) are used to anchor the connection.

[0053] The communication link 125 shown in the wireless communication system 100 may include uplink transmission from UE 115 to base station 105, or downlink transmission from base station 105 to UE 115. The carrier may carry downlink or uplink communication (e.g., in FDD mode), or may be configured to carry both downlink and uplink communication (e.g., in TDD mode).

[0054] A carrier can be associated with a specific bandwidth of the radio frequency spectrum, and in some examples, the carrier bandwidth can be referred to as the carrier or the “system bandwidth” of the wireless communication system 100. For example, the carrier bandwidth can be one of several defined bandwidths of a carrier used for a particular radio access technology (e.g., 1.4, 3, 5, 10, 15, 20, 40, or 80 MHz). Devices of the wireless communication system 100 (e.g., base station 105, UE 115, or both) can have a hardware configuration that supports communication on a specific carrier bandwidth, or can be configured to support communication on one of a set of carrier bandwidths. In some examples, the wireless communication system 100 may include a base station 105 or UE 115 that supports simultaneous communication via carriers associated with multiple carrier bandwidths. In some examples, each served UE 115 can be configured to operate on a portion (e.g., a subband, BWP) or all of the carrier bandwidth.

[0055] The signal waveform transmitted on a carrier can consist of multiple subcarriers (e.g., using multi-carrier modulation (MCM) techniques, such as orthogonal frequency division multiplexing (OFDM) or discrete Fourier transform extended OFDM (DFT-S-OFDM)). In a system employing MCM, a resource element can consist of one symbol period (e.g., the duration of a modulation symbol) and one subcarrier, where the symbol period and subcarrier spacing are inversely related. The number of bits carried by each resource element can depend on the modulation scheme (e.g., the order of the modulation scheme, the decoding rate of the modulation scheme, or both). Therefore, the more resource elements the UE 115 receives and the higher the order of the modulation scheme, the higher the data rate the UE 115 can achieve. Wireless communication resources can refer to a combination of radio frequency spectrum resources, temporal resources, and spatial resources (e.g., spatial layers or beams), and the use of multiple spatial layers can further increase the data rate or data integrity used for communication with the UE 115.

[0056] One or more parameter sets can be supported for a carrier, where the parameter set may include subcarrier spacing (Δf) and a cyclic prefix. A carrier can be divided into one or more BWPs with the same or different parameter sets. In some examples, the UE115 can be configured with multiple BWPs. In some examples, a single BWP of a carrier can be active at a given time, and the communication of the UE115 can be restricted to one or more active BWPs.

[0057] The time interval of base station 105 or UE 115 can be expressed as a multiple of a basic time unit, such as T. s =1 / (Δf) max ·N f The sampling period is ) seconds, where Δf max This can represent the maximum supported subcarrier spacing, and N f This can represent the maximum supported Discrete Fourier Transform (DFT) size. The time interval of the communication resource can be organized according to each radio frame having a specified duration (e.g., 10 milliseconds (ms)). Each radio frame can be identified by a System Frame Number (SFN) (e.g., ranging from 0 to 1023).

[0058] Each frame may include multiple consecutively numbered subframes or time slots, and each subframe or time slot may have the same duration. In some examples, (e.g., in the time domain) a frame may be divided into subframes, and each subframe may also be divided into multiple time slots. Alternatively, each frame may include a variable number of time slots, and the number of time slots may depend on the subcarrier spacing. Each time slot may include multiple symbol periods (e.g., depending on the length of the cyclic prefix preceding each symbol period). In some wireless communication systems 100, time slots may also be divided into multiple mini-slots containing one or more symbols. In addition to the cyclic prefix, each symbol period may contain one or more (e.g., N) symbols. f (Number) sampling periods. The duration of a symbol period can depend on the subcarrier spacing or the operating frequency band.

[0059] A subframe, time slot, mini-slot, or symbol can be the smallest scheduling unit of the wireless communication system 100 (e.g., in the time domain) and can be referred to as a transmission time interval (TTI). In some examples, the duration of the TTI (i.e., the number of symbol periods in the TTI) can be variable. Alternatively, the smallest scheduling unit of the wireless communication system 100 can be dynamically selected (e.g., in a burst of shortened TTIs (sTTIs)).

[0060] Physical channels can be multiplexed on a carrier using various techniques. For example, one or more Time Division Multiplexing (TDM), Frequency Division Multiplexing (FDM), or hybrid TDM-FDM techniques can be used to multiplex physical control channels and physical data channels on a downlink carrier. The control region (e.g., control resource set (CORESET)) of the physical control channel can be defined by multiple symbol periods and can be extended across the system bandwidth or a subset of the system bandwidth of the carrier. One or more control regions (e.g., CORESET) can be configured for a set of UEs 115. For example, one or more UEs 115 can monitor or search for control regions for control information based on one or more search space sets, and each search space set can include one or more control channel candidates from one or more aggregation levels arranged in a cascaded manner. The aggregation level for control channel candidates can refer to the number of control channel resources (e.g., control channel elements (CCEs)) associated with coded information for a control information format having a given payload size. The search space set can include a common search space set configured to send control information to multiple UEs 115 and a UE-specific search space set configured to send control information to a specific UE 115.

[0061] Each base station 105 may provide communication coverage via one or more cells, such as macro cells, small cells, hotspots, or other types of cells, or any combination thereof. The term "cell" may refer to a logical communication entity used to communicate with base station 105 (e.g., via a carrier) and may be associated with an identifier used to distinguish neighboring cells (e.g., Physical Cell Identifier (PCID), Virtual Cell Identifier (VCID), or others). In some examples, a cell may also refer to a geographic coverage area 110 or a portion of geographic coverage area 110 (e.g., a sector) on which a logical communication entity operates. Depending on various factors such as the capabilities of base station 105, the range of such cells can vary from smaller areas (e.g., structures, subsets of structures) to larger areas. For example, a cell may be or may include a building, a subset of buildings, or external space between or overlapping with geographic coverage areas 110.

[0062] Macro cells typically cover a relatively large geographic area (e.g., a radius of several kilometers) and can allow unrestricted access for UE 115 with a service subscription to a network provider supporting the macro cell. In contrast, small cells can be associated with a lower-power base station 105 and can operate in the same or different (e.g., licensed, unlicensed) frequency bands as macro cells. Small cells can provide unrestricted access to UE 115 with a service subscription to a network provider, or restricted access to UE 115 associated with a small cell (e.g., UE 115 in a Closed Subscriber Group (CSG), UE 115 associated with a user in a home or office). Base station 105 can support one or more cells and can also support communication on one or more cells using one or more component carriers.

[0063] In some examples, a carrier can support multiple cells, and different cells can be configured according to different protocol types that can provide access for different types of devices (e.g., MTC, Narrowband IoT (NB-IoT), Enhanced Mobile Broadband (eMBB)).

[0064] In some examples, base station 105 may be mobile, thus providing communication coverage for mobile geographic coverage area 110. In some examples, different geographic coverage areas 110 associated with different technologies may overlap, but different geographic coverage areas 110 may be supported by the same base station 105. In other examples, overlapping geographic coverage areas 110 associated with different technologies may be supported by different base stations 105. Wireless communication system 100 may include, for example, a heterogeneous network, in which different types of base stations 105 use the same or different radio access technologies to provide coverage for various geographic coverage areas 110.

[0065] The wireless communication system 100 can support synchronous or asynchronous operation. For synchronous operation, base stations 105 can have similar frame timing, and transmissions from different base stations 105 can be approximately aligned in time. For asynchronous operation, base stations 105 can have different frame timing, and in some examples, transmissions from different base stations 105 can be misaligned in time. The techniques described herein can be used for both synchronous and asynchronous operation.

[0066] Some UE 115 devices (such as MTC or IoT devices) can be low-cost or low-complexity devices and can provide automated communication between machines (e.g., via machine-to-machine (M2M) communication). M2M communication or MTC can refer to data communication technologies that allow devices to communicate with each other or with base station 105 without human intervention. In some examples, M2M communication or MTC can include communication from devices that integrate sensors or meters to measure or capture information and relay such information to a central server or application that uses the information or presents it to a person interacting with the application. Some UE 115 devices can be designed to collect information or enable automated behavior of machines or other devices. Examples of applications for MTC devices include smart metering, inventory monitoring, water level monitoring, equipment monitoring, healthcare monitoring, wildlife monitoring, weather and geological event monitoring, fleet management and tracking, remote security sensing, physical access control, and transaction-based commercial toll collection.

[0067] Some UE 115s can be configured to operate in reduced-power modes, such as half-duplex communication (e.g., a mode that supports unidirectional communication via transmit or receive but not simultaneous transmit and receive). In some examples, half-duplex communication can be performed at a reduced peak rate. Other power-saving techniques for UE 115s include entering a power-saving deep sleep mode when not engaged in active communication, operating on limited bandwidth (e.g., according to narrowband communication), or a combination of these techniques. For example, some UE 115s can be configured to operate using a narrowband protocol type associated with a defined portion or range (e.g., a set of subcarriers or resource blocks (RBs)) within the carrier, within the carrier's guard band, or outside the carrier.

[0068] Wireless communication system 100 can be configured to support ultra-reliable communication or low-latency communication, or various combinations thereof. For example, wireless communication system 100 can be configured to support ultra-reliable low-latency communication (URLLC) or mission-critical communication. UE 115 can be designed to support ultra-reliable, low-latency, or mission-critical functions (e.g., mission-critical functions). Ultra-reliable communication may include private or group communication and may be supported by one or more mission-critical services such as Mission-Critical Push-to-Talk (MCPTT), Mission-Critical Video (MCVideo), or Mission-Critical Data (MCData). Support for mission-critical functions may include service prioritization, and mission-critical services may be used for public safety or general commercial applications. The terms ultra-reliable, low-latency, mission-critical, and ultra-reliable low-latency are used interchangeably herein.

[0069] In some examples, UE 115 may also be able to communicate directly with other UE 115 via device-to-device (D2D) communication link 135 (e.g., using peer-to-peer (P2P) or D2D protocols). One or more UE 115s utilizing D2D communication may be within the geographic coverage area 110 of base station 105. Other UE 115s in such a group may be outside the geographic coverage area 110 of base station 105, or otherwise unable to receive transmissions from base station 105. In some examples, the group of UE 115s communicating via D2D communication may utilize a one-to-many (1:M) system, in which each UE 115 transmits to every other UE 115 in the group. In some examples, base station 105 facilitates the scheduling of resources for D2D communication. In other cases, D2D communication is performed between UE 115s without the involvement of base station 105.

[0070] In some systems, the D2D communication link 135 may be an example of a communication channel (such as a side-link communication channel) between vehicles (e.g., UE 115). In some examples, vehicles may communicate using vehicle-to-everything (V2X) communication, vehicle-to-vehicle (V2V) communication, or some combination thereof. Vehicles may use signals to notify information related to traffic conditions, signal control, weather, safety, emergencies, or any other information related to the V2X system. In some examples, vehicles in a V2X system may communicate with roadside infrastructure (such as roadside units), or communicate with the network via one or more network nodes (e.g., base station 105) using vehicle-to-network (V2N) communication, or communicate with both.

[0071] Core network 130 can provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. Core network 130 can be an evolved packet core (EPC) or a 5G core (5GC), and can include at least one control plane entity (e.g., a mobility management entity (MME), access and mobility management function (AMF)) managing access and mobility, and at least one user plane entity (e.g., a serving gateway (S-GW), packet data network (PDN) gateway (P-GW), or user plane function (UPF)) routing packets or interconnects to external networks. The control plane entity can manage non-access stratum (NAS) functions, such as mobility, authentication, and bearer management, for UE 115 served by base station 105 associated with core network 130. User IP packets can be transmitted through the user plane entity, which can provide IP address allocation and other functions. This user plane entity can connect to network operator IP service 150. Network operator IP services 150 may include access to the Internet, (multiple) intranets, IP Multimedia Subsystem (IMS), or packet-switched streaming services.

[0072] Some network devices (such as base station 105) may include sub-components such as access network entity 140, which may be an example of an access node controller (ANC). Each access network entity 140 may communicate with UE 115 through one or more other access network transport entities 145, which may be referred to as a radio head, smart radio head, or transmit / receive point (TRP). Each access network transport entity 145 may include one or more antenna panels. In some configurations, the various functions of each access network entity 140 or base station 105 may be distributed across various network devices (e.g., radio heads and ANCs) or combined into a single network device (e.g., base station 105).

[0073] Wireless communication system 100 can operate using one or more frequency bands typically in the range of 300 MHz to 300 GHz. The region from 300 MHz to 3 GHz is generally referred to as the Ultra High Frequency (UHF) region or decimeter band because the wavelength range is from approximately one decimeter to one meter. UHF waves can be blocked or redirected by buildings and environmental features, but the waves can penetrate structures sufficiently to allow macrocells to provide service to UE 115 located indoors. Compared to transmissions using smaller frequencies and longer waves in the High Frequency (HF) or Very High Frequency (VHF) portions of the spectrum below 300 MHz, UHF wave transmission can be associated with smaller antennas and shorter ranges (e.g., less than 100 km).

[0074] The wireless communication system 100 can also operate in the ultra-high frequency (SHF) region using a frequency band from 3 GHz to 30 GHz (also known as the centimeter band), or in the extremely high frequency (EHF) region of the spectrum (e.g., from 30 GHz to 300 GHz) (also known as the millimeter band). In some examples, the wireless communication system 100 can support millimeter-wave (mmW) communication between the UE 115 and the base station 105, and the EHF antennas of the individual devices can be smaller and more closely spaced than UHF antennas. In some examples, this can facilitate the use of antenna arrays within the devices. However, the propagation of EHF transmissions may be subject to even greater atmospheric attenuation and a shorter range than SHF or UHF transmissions. The techniques disclosed herein can be employed for transmissions across one or more different frequency regions, and the designated use of frequency bands across these frequency regions may vary by country or regulatory body.

[0075] Wireless communication system 100 may use licensed and unlicensed radio spectrum bands. For example, wireless communication system 100 may employ licensed assisted access (LAA), unlicensed LTE (LTE-U) radio access technology, or NR technology in unlicensed bands such as the 5 GHz Industrial, Scientific, and Medical (ISM) band. When operating in unlicensed radio spectrum bands, devices such as base station 105 and UE 115 may employ carrier sensing for collision detection and avoidance. In some examples, operation in unlicensed bands may be based on carrier aggregation configuration along with component carriers operating in licensed bands (e.g., LAA). Operation in unlicensed spectrum may include downlink transmissions, uplink transmissions, P2P transmissions, or D2D transmissions, etc.

[0076] Base station 105 or UE 115 may be equipped with multiple antennas, which can be used to employ techniques such as transmit diversity, receive diversity, multiple-input multiple-output (MIMO) communication, or beamforming. The antennas of base station 105 or UE 115 may be located within one or more antenna arrays or antenna panels, which can support MIMO operation or transmit or receive beamforming. For example, one or more base station antennas or antenna arrays may be located together at an antenna assembly such as an antenna tower. In some examples, the antennas or antenna arrays associated with base station 105 may be located in different geographical locations. Base station 105 may have an antenna array with multiple rows and columns of antenna ports, which base station 105 can use to support beamforming for communication with UE 115. Similarly, UE 115 may have one or more antenna arrays capable of supporting various MIMO or beamforming operations. Alternatively or additionally, antenna panels may support radio frequency beamforming of signals transmitted via antenna ports.

[0077] Base station 105 or UE 115 can use MIMO communication to utilize multipath signal propagation and improve spectral efficiency by transmitting or receiving multiple signals via different spatial layers. Such a technique is called spatial multiplexing. For example, multiple signals can be transmitted by a transmitting device via different antennas or different combinations of antennas. Similarly, multiple signals can be received by a receiving device via different antennas or different combinations of antennas. Each of the multiple signals can be referred to as a separate spatial stream and can carry bits associated with the same data stream (e.g., the same codeword) or different data streams (e.g., different codewords). Different spatial layers can be associated with different antenna ports used for channel measurement and reporting. MIMO techniques include single-user MIMO (SU-MIMO), where multiple spatial layers are transmitted to the same receiving device, and multi-user MIMO (MU-MIMO), where multiple spatial layers are transmitted to multiple devices.

[0078] Beamforming (also known as spatial filtering, directional transmission, or directional reception) is a signal processing technique that can be used at a transmitting or receiving device (e.g., base station 105, UE 115) to shape or steer an antenna beam (e.g., a transmit beam, a receive beam) along a spatial path between the transmitting and receiving devices. Beamforming can be achieved by combining signals transmitted via antenna elements in an antenna array so that some signals propagating in a particular direction relative to the antenna array experience constructive interference, while other signals experience destructive interference. Adjustments to the signals transmitted via the antenna elements can include the transmitting or receiving device applying amplitude shift, phase shift, or both to the signals carried via the antenna elements associated with that device. The adjustments associated with each antenna element can be defined by a beamforming weight set associated with a specific direction (e.g., relative to the antenna array of the transmitting or receiving device, or relative to another direction).

[0079] Base station 105 or UE 115 may use beam scanning technology as part of beamforming operations. For example, base station 105 may use multiple antennas or antenna arrays (e.g., antenna panels) to perform beamforming operations for directional communication with UE 115. Some signals (e.g., synchronization signals, reference signals, beam selection signals, or other control signals) may be transmitted multiple times by base station 105 in different directions. For example, base station 105 may transmit signals according to different beamforming weight sets associated with different transmission directions. Transmissions in different beam directions may be used (e.g., by a transmitting device such as base station 105 or a receiving device such as UE 115) to identify beam directions for subsequent transmission or reception by base station 105.

[0080] Some signals, such as data signals associated with a specific receiving device, may be transmitted by base station 105 in a single beam direction (e.g., the direction associated with a receiving device such as UE 115). In some examples, the beam direction associated with transmission along a single beam direction may be determined based on the signals transmitted in one or more beam directions. For example, UE 115 may receive one or more signals transmitted by base station 105 in different directions and may report to base station 105 an indication of the signal received by UE 115 with the highest signal quality or otherwise acceptable signal quality.

[0081] In some examples, transmissions performed by a device (e.g., by base station 105 or UE 115) may be executed using multiple beam directions, and the device may use a combination of digital precoding or radio frequency beamforming to generate combined beams for transmission (e.g., from base station 105 to UE 115). UE 115 may report feedback indicating precoding weights for one or more beam directions, and this feedback may correspond to a configured number of beams across the system bandwidth or one or more subbands. Base station 105 may transmit reference signals (e.g., cell-specific reference signals (CRS), channel state information reference signals (CSI-RS)), which may be precoded or unprecoded. UE 115 may provide feedback for beam selection, which may be a precoding matrix indicator (PMI) or codebook-based feedback (e.g., multi-panel type codebook, linear combination type codebook, port selection type codebook). Although these techniques are described with reference to signals transmitted by base station 105 in one or more directions, UE 115 may employ similar techniques to transmit signals multiple times in different directions (e.g., to identify beam direction for subsequent transmission or reception by UE 115) or to transmit signals in a single direction (e.g., to transmit data to a receiving device).

[0082] A receiving device (e.g., UE 115) may attempt multiple receiving configurations (e.g., directional listening) when receiving various signals such as synchronization signals, reference signals, beam selection signals, or other control signals from base station 105. For example, the receiving device may attempt multiple receiving directions by receiving via different antenna subarrays, by processing the received signals according to different antenna subarrays, by receiving according to different sets of receiving beamforming weights applied to signals received at multiple antenna elements of the antenna array (e.g., different sets of directional listening weights), or by processing the received signals according to different sets of receiving beamforming weights applied to signals received at multiple antenna elements of the antenna array. Any of these different receiving configurations or receiving directions may be referred to as "listening." In some examples, the receiving device may use a single receiving configuration to receive along a single beam direction (e.g., when receiving data signals). A single receiving configuration may be aligned based on a beam direction determined by listening according to different receiving configuration directions (e.g., a beam direction determined to have the highest signal strength, highest signal-to-noise ratio (SNR), or otherwise acceptable signal quality based on listening according to multiple beam directions).

[0083] The wireless communication system 100 can be a packet-based network operating according to a layered protocol stack. In the user plane, communication at the bearer layer or Packet Data Convergence Protocol (PDCP) layer can be IP-based. The Radio Link Control (RLC) layer can perform packet segmentation and reassembly for communication over logical channels. The Media Access Control (MAC) layer can perform priority processing and multiplex logical channels into transport channels. The MAC layer can also use error detection techniques, error correction techniques, or both to support retransmissions at the MAC layer to improve link efficiency. In the control plane, the Radio Resource Control (RRC) protocol layer can provide the establishment, configuration, and maintenance of RRC connections between the UE 115 and the base station 105 or core network 130 that supports radio bearers for user plane data. At the physical layer, transport channels can be mapped to physical channels.

[0084] UE 115 and base station 105 can support data retransmission to increase the likelihood of successful data reception. Hybrid Automatic Repeat Request (HARQ) feedback is a technique used to increase the likelihood of correct data reception on communication link 125. HARQ can include a combination of error detection (e.g., using Cyclic Redundancy Check (CRC)), forward error correction (FEC), and retransmission (e.g., Automatic Repeat Request (ARQ)). HARQ can improve throughput at the MAC layer under poor radio conditions (e.g., low signal-to-noise ratio conditions). In some examples, the device can support HARQ feedback within the same time slot, where the device can provide HARQ feedback for data received in previous symbols within that time slot. In other cases, the device can provide HARQ feedback in subsequent time slots or according to some other time interval.

[0085] The technology implemented by wireless communication system 100 can provide priority ordering of resources when selecting resources for sidelink communication. In some cases, wireless communication system 100 may support sidelink communication, such as for V2X systems. In some cases, cellular V2X communication, including or excluding sidelink communication, may be deployed in unlicensed spectrum. However, unlicensed spectrum can also be utilized by other technologies such as Wi-Fi, and the use of unlicensed spectrum may be subject to some regulatory conditions. For example, UE 115 may perform LBT (e.g., Type 1 or Type 2 channel access) before communication, and UE 115 may transmit if the channel is determined to be available. Additionally, in some cases, the COT of the channel may not exceed a pre-configured amount of time (e.g., it may be a regulatory requirement for unlicensed radio spectrum).

[0086] The wireless communication system 100 can support autonomous resource allocation. For example, UE 115 can perform channel sensing and select resources for sidelink transmission on sidelink channels in unlicensed radio spectrum bands. UE 115 can decode control information such as SCI to determine which upcoming resources are available and which are reserved. The UE can also perform RSRP measurement from UE 115 that has reserved resources to determine whether the RSRP projected onto the reserved resources is less than an RSRP threshold. If no other device has reserved the resource, or if the resource has been reserved but the RSRP measured by the UE reserving the resource is less than the RSRP threshold, or both, the UE can identify the resource as available.

[0087] UE 115 can identify which resources within a resource selection window are available for sidelink transmission and prioritize some resources to prevent transmission gaps in a COT shared by UEs including UE 115. If there is no sidelink transmission from a UE sharing the COT within a time slot, a transmission gap can be created in the COT, and UEs sharing the COT (including UE 115) may lose access to the channel medium or be unable to acquire the channel medium. For example, unlicensed radio spectrum bands may be shared by other technologies (e.g., Wi-Fi). If the transmission gap is greater than a duration threshold (e.g., 16µs or 25µs), the UE may need to perform LBT-type channel access again to regain access to the medium. In some cases, UE 115 can prioritize available resources in time slots where no resources have been at least partially reserved by another device. For example, if available resources exist in a time slot that is not fully reserved (i.e., all resources in the time slot are identified as available), UE 115 can prioritize resources in the time slot when selecting resources for sidelink transmission. Alternatively, UE 115 may prioritize available resources in earlier slots of the COT or resource selection window. For example, UE 115 may identify higher priority windows that are earlier in the resource selection window, and available resources in higher priority windows may be selected over other resources (e.g., resources that are later in the resource selection window).

[0088] Figure 2 An example of a wireless communication system 200 supporting technology for resource selection for sidelink communication in an unlicensed radio spectrum band is illustrated according to aspects of this disclosure. In some examples, wireless communication system 200 may implement aspects of wireless communication system 100. Wireless communication system 200 may include UE 215-a and UE 215-b, which may be references Figure 1 An example of UE 115 is described. The wireless communication system 200 also includes a base station 205, which may be a reference. Figure 1 An example of a base station 105 is described.

[0089] Base station 205 can communicate with UE 215-a and UE 215-b via communication link 220. For example, base station 205 can communicate with UE 215-a via communication link 220-a and with UE 215-b via communication link 220-b. Wireless communication system 200 can also support sidelink communication. For example, UE 215-a and UE 215-b can communicate with each other via sidelink 210. In some examples, wireless communication system 200 can support D2D or V2X communication, which can utilize sidelink 210 for communication between devices. For example, in some cases, UE 215 can be an example of a vehicle UE (V-UE) or a pedestrian UE (P-UE).

[0090] In some cases, the wireless communication system 200 can support autonomous resource allocation on the sidelink 210. For example, the UE 215 can identify candidate resources for sidelink transmission based on sensing, and the UE 215 can select resources from the candidate resources for transmission on the sidelink 210. The UE 215 can select resource 225 for the current transmission (e.g., resource 225-a) and reserve multiple additional future resources (e.g., resources 225-b and 225-c), which can be used for additional packets or packet retransmissions. Resources can correspond to, for example, one or more time slots 230 and one or more subchannels 235; each subchannel can include multiple consecutive (or non-consecutive, e.g., interleaved) RBs.

[0091] To identify available resources, UE 215 can monitor and decode all transmissions on unlicensed radio spectrum bands. In some cases, UE 215 can measure RSRP for each decoding. When UE 215 has packets to transmit, UE 215 can determine a sensing window (e.g., a past time-frequency window on the unlicensed radio spectrum band) and determine available resources in future selection windows based on control information decoding and RSRP measurements within that sensing window. For example, control information received in the sensing window (e.g., SCI) can indicate reserved resources in the selection window. In some cases, for example, if a resource is reserved, the measured RSRP can be projected onto the corresponding future resource. RSRP projection in the selection window can indicate whether a resource is available. For example, if a resource is not reserved, or if a resource is reserved but the RSRP measurement is less than an RSRP threshold, the resource may be available.

[0092] UE 215 can identify which resources are available and which are reserved in the selection window. UE 215 can reserve resources from the available resources for sidelink transmissions, and reserve multiple additional resources for additional transmissions (e.g., retransmissions). For example, UE 215-a can reserve resource 225-a for sidelink transmissions, and UE 215-a can reserve resources 225-b and 225-c for potential retransmissions of sidelink transmissions. In some wireless communication systems, UE 115 can randomly select from the available resources. For example, in some wireless communication systems, each available resource may have an equal probability of being selected.

[0093] In some cases, wireless communication system 200 can support communication on unlicensed radio spectrum bands. In some cases, communication on sidelink 210 can use unlicensed radio spectrum bands. Some systems can use licensed spectrum to implement sidelink communication, such as sharing spectrum in licensed cellular bands or using dedicated spectrum for Intelligent Transport Systems (ITS). In some examples, wireless communication system 200 can implement aspects of these systems while supporting sidelink communication using unlicensed spectrum.

[0094] Unlicensed radio spectrum can be shared by various technologies. For example, unlicensed radio spectrum bands can be utilized by new radio communications and Wi-Fi. In some cases, to ensure fair use of unlicensed radio spectrum bands, devices may be subject to certain regulatory conditions. For example, a device may perform an LBT (Level-Based Transmission) procedure to determine whether the channel medium is available before transmission. If the channel is sensed to be idle (e.g., the energy measured in the channel is below a threshold for energy-based channel sensing), the device may access the channel medium and transmit. In some examples, channel sensing may involve a random backoff before the device can access the channel. In some cases, a device may occupy the channel for a configured amount of time. For example, a device may acquire a channel with COT (Content-Operated-Operated) and may configure the maximum duration of COT for the device or for the wireless communication system 200.

[0095] In some cases, UE 215 may share a set of resources on an unlicensed radio spectrum band for sidelink communication. In some cases, this set of resources may be resources in a COT (Cross-Operation Target). A COT may span multiple time slots and include one or more resource blocks in frequency. A COT may be initiated by UE 215, base station 205, or another network node. For example, in a V2X system, UE 215, base station 205, or a roadside unit may initiate a COT based on an LBT (Low-Band Target) procedure.

[0096] In some examples, transmissions from the device can be limited to multiple time slots within the COT. For example, UE 215 can be supported in transmitting one packet or transport block at a time within the COT. In some cases, each transmission (e.g., including retransmissions) can be limited to multiple time slots within the COT. In some examples, UE 215 can be supported in transmitting multiple packets or transport blocks within the COT with or without retransmissions. In some cases, the COT can be shared by multiple UE 215s. For example, another UE 215 can share a COT initiated by UE 215.

[0097] In some cases, UE 215 may lose the channel when sidelink transmissions from a UE 215 sharing a COT are discontinuous. For example, UE 215-a may transmit on sidelink 210 using resources 225-a, 225-b, and 225-c. There may be two time slots 230 between resources 225, which could result in a transmission gap if no other UE 215 sharing a COT transmits in these two time slots. If there is no transmission during these time slots, other devices can sense that the channel is available during the transmission gap and access the medium. For example, a UE sharing a COT including UE 215-a may lose the channel medium between resources 225-a and 225-b. In some cases, UE 215 may assume that the channel is lost after a transmission gap of the configured duration (e.g., even if the channel is still available). UE 215 may then perform LBT again to resume transmission after the transmission gap. This may increase the latency of sidelink communication and reduce reliability.

[0098] To improve reliability and reduce sidelink communication latency, UE 115, such as UE 215, can implement techniques to reduce the probability of transmission gaps in the COT. For example, UE 215 can perform resource selection by prioritizing some resources used for sidelink transmissions to reduce the probability of transmission gaps. By implementing these techniques, UE 215 sharing the COT can maintain the channel medium after the COT has been initiated and avoid performing additional LBTs to reacquire the channel medium.

[0099] In some examples, UE 215 can identify available resources within a resource selection window and prioritize some resources when selecting resources for sidelink transmissions. For example, UE 215 can identify available resources and assign them priorities such that some of the available resources can be selected over others. For example, a first resource set can be prioritized over a second resource set. In some cases, when scheduling sidelink transmissions, UE 215 can select from the first resource set (e.g., not from the second resource set). For example, UE 215 can randomly select from the first resource set, where the first resource set may include resources that reduce transmission gaps or the possibility that UE 215 loses control of the channel medium.

[0100] In some cases, UE 215 can choose between a first resource set and a second resource set, but resources in the first resource set may have a higher probability of being selected. For example, UE 215 can assign different selection probabilities to resources in the first and second sets, making resources in the first set have a higher probability than resources in the second set, and UE 215 can select resources for sidelink transmissions based on the selection probabilities. In some cases, UE 215 can assign different weighting factors to the first and second sets when determining resource selection probabilities. For example, using different resource selection probabilities, it is still possible to select resources from the second set, but it is more likely to select resources from the first set. These techniques can be implemented to select resources for the current transmission or to select one or more additional resources for additional transmissions (e.g., resources for retransmissions of the current transmission).

[0101] In some examples, resources in time slots without any pre-reserved resources can be prioritized for selection. For example, time slots without any portion of pre-reserved resources (e.g., subchannels, resource blocks, or subcarriers) can be prioritized. If a time slot includes some available resources, but other subcarriers of that time slot have been reserved by another device, then that time slot may not be prioritized for selection. By prioritizing resources in time slots that have not yet been at least partially reserved, transmission gaps (e.g., the duration of transmission gaps) created by time slots without pre-reserved resources can be reduced or eliminated within a shared COT. This increases the likelihood that UE 215 will share the COT for maintaining the channel medium and prevents UE 215 from performing additional LBTs.

[0102] For example, UE 215 performing resource selection may group available resources in the COT or selection window into at least two groups. The first group may include resources from time slots without reserved resources. For example, all resources within those time slots on unlicensed radio spectrum bands may be identified as available. The second group may include available resources from time slots with some reserved resources. For example, UE 215 may have identified available resources in a time slot, and that time slot may have some resources reserved by another device. In some cases of the first example, UE 215 may select resources for sidelink transmission from the first group. For example, UE 215 may select resources from time slots that are not partially reserved, and UE 215 may not select resources from partially reserved time slots. In some cases of the first example, UE 215 may select from either the first or second group, but resources from the first group may have a higher probability of being selected.

[0103] In some examples, available resources in earlier slots of the COT or resource selection window can be prioritized for selection. For example, UE 215 can determine a sub-selection window or a high-priority window within the resource selection window. Available resources within a sub-selection window can be prioritized for selection over resources outside the sub-selection window. In some cases, a sub-selection window can be a subset of the COT or selection window (e.g., its duration can be less than the duration of the COT or selection window). The starting position of the sub-selection window can be determined based on the processing speed of UE 215. For example, the starting position can be based on the UE packet arrival and readiness timeline. For example, if UE 215 has packets ready for transmission in slot n, the sub-selection window can start from slot n+1. In another example, if UE 215 identifies the first slot with available resources as slot n+k, the sub-selection window can start from slot n+k+1. UE 215 can select resources from the sub-selection window for sidelink transmission.

[0104] In some cases, the selection from a sub-selection window can be random. In some examples, resources that are not at least partially reserved and are in an earlier slot in the COT or selection window can be given priority for selection. For example, in some cases, UE 215 can weight resources in slots that are not partially reserved based on their earlyness within the selection window.

[0105] In some examples, UE 215 can select resources from available resources based on the location of the time slot carrying the resource, whether the time slot carrying the resource is at least partially reserved, or both. For example, UE 215 can select earlier available resources for current transmissions based on which time slots are not reserved, and select resources for future transmissions.

[0106] Figure 3 An example of an autonomous resource selection scheme 300 supporting technology for resource selection in sidelink communication in an unlicensed radio spectrum band is illustrated. In some examples, the autonomous resource selection scheme 300 can implement aspects of the wireless communication system 100.

[0107] For reference Figure 2 As described, UE 115 can implement an autonomous resource selection scheme 300 to select available resources on a channel in an unlicensed radio spectrum band for sidelink communication during COT. This channel may include one or more resource blocks or one or more sub-channels 320 in a frequency band. In some cases, multiple resource blocks may form a sub-channel 320. COT may span one or more time slots. For example, COT may span twenty time slots. COT may be initiated by UE 115, base station 105, or another radio node. For example, the radio node may be another UE 115, a roadside unit, a transmit / receive point, etc.

[0108] UE 115 can perform channel sensing and access the wireless communication channel based on the sensing results. For example, UE 115 can identify available or candidate resources for sidelink transmission and select resources for sidelink transmission from the candidate resources. For example, candidate resources may include unused resource 310. By performing sensing, UE 115 can identify reserved resource 305, which can be reserved by other UEs 115 sharing the COT; remaining resources within the resource selection window can be identified as candidate resources for resource selection.

[0109] To perform channel sensing and identify available resources, UE 115 can monitor and decode incoming transmissions. For example, UE 115 can monitor and decode all transmissions on the channel. In some cases, UE 115 can perform RSRP measurements for each decode. When resource selection has been triggered at 335 or a packet has arrived for transmission by UE 115 (e.g., UE 115 has packets to send), UE 115 can determine sensing window 325. Sensing window 325 can be a past window, corresponding to previously received and decoded signaling. UE 115 can determine available resources based on control information (e.g., SCI) decoding and RSRP measurements within the sensing window. UE 115 can identify available resources in resource selection window 330 (e.g., a future window) by projecting the decoding and measurement results from sensing window 325 (e.g., from transmissions on previously used resource 315) onto resource selection window 330. To identify available resources, SCI decoding can indicate whether a resource in resource selection window 330 has already been reserved (e.g., corresponding to reserved resource 305). The measured RSRP can be projected onto the corresponding future reserved resource 305. UE 115 can determine resource availability based on whether the resource is not reserved or whether the resource is reserved but the projected RSRP is less than an RSRP threshold. In some cases, the RSRP threshold can be configured by base station 105, pre-configured at the UE, or determined by the UE.

[0110] UE 115 can select an initial resource and reserve multiple additional resources. For example, UE 115 can select a first resource for initial transmission and select additional resources for future transmissions. The additional resources can be used for transmission of different packets or for retransmission of packets sent using the first resource. In the example, the first UE 115 may have already selected resources 315-a, 305-a, and 305-b for transmission. The first UE 115 can indicate in the control information for transmission at resource 315-a that resources 305-a and 305-b are reserved. The second UE 115, performing channel sensing at 335, can decode the control information from resource 315-a in sensing window 325 and determine that resources 305-a and 305-b are reserved in resource selection window 330. Therefore, the second UE 115 can identify available resources in the selection window based on performing channel sensing on sensing window 325.

[0111] In some wireless communication systems, UE 115 can randomly select resources from available resources. However, this may lead to transmission gaps for UE 115, potentially causing UE 115 sharing a COT to lose channel medium. The UE 115 described herein implements a technique for prioritizing available resources. For example, UE 115 can prioritize resources in unreserved time slots or resources in earlier time slots within the resource selection window. The UE 115 described herein can select resources based on priority ranking to reduce the likelihood of transmission gaps in the COT, such as by selecting resources among reserved resources. Selecting resources based on a priority ranking scheme can improve reliability and reduce latency for sidelink communication on unlicensed radio spectrum bands. References Figure 4 This section describes some examples of prioritizing resources for selection.

[0112] Figure 4 An example of a resource selection scheme 400 supporting a technology for resource selection in a sidelink communication band in an unlicensed radio spectrum band, according to aspects of this disclosure, is illustrated. In some examples, resource selection scheme 400 may implement aspects of wireless communication system 100.

[0113] UE 115 can select resources on a channel within an unlicensed radio spectrum band. UE 115 can select resources within a resource selection window 420 of the COT. UE 115 can identify reserved resources 405 and available resources 410 within the resource selection window 420. Reserved resources 405 can be sensed as reserved by other UEs 115 sharing the COT, where one or more resources from available resources 410 can be selected by UE 115 for sidelink transmission. The resource selection window 420 can span multiple time slots (e.g., time slot 415-a to at least time slot 415-l), and the radio channel can include one or more resource blocks in frequency. In some cases, the resource selection window 420 can be equal to or less than (e.g., in time) the COT. In some cases, the selection window can extend beyond the end of the COT.

[0114] UE 115 may reserve a first resource allocation in available resource 410 for sidelink transmission, and reserve multiple additional available resource allocations for additional sidelink transmission (e.g., retransmission). In some wireless communication systems, UE 115 may randomly select the resource allocation of available resource 410. The UE 115 described herein implements a technique for prioritizing available resource 410 and selecting based on this priority. Prioritizing available resource 410 can reduce the likelihood of transmission gaps that could cause UE 115 and other UEs 115 sharing the COT to lose transmission medium.

[0115] In the first example, available resources 410 in time slot 415 without any reserved resources 405 can be preferentially selected. For example, time slots 415-a, 415-b, 415-c, 415-f, 415-h, 415-j, and 415-k can each have reserved resources 405 and available resources 410. Besides available resources 410, time slots 415-d, 415-e, 415-g, 415-i, and 415-l can have no reserved resources 405. UE115 can prioritize available resources 410 in time slots 415 without any at least partial reservation, where available resources 410 in time slots 415-d, 415-e, 415-g, 415-i, and 415-l are preferentially selected.

[0116] In some cases, UE 115 can group available resources 410. For example, a first group may include available resources 410 from time slots 415 (e.g., time slots 415-d, 415-e, 415-g, 415-i, and 415-l) that have no reserved resources 405, and a second group may include available resources 410 from at least partially reserved time slots 415 (e.g., time slots 415-a, 415-b, 415-c, 415-f, 415-h, 415-j, and 415-k). In some cases, UE 115 can select resources for sidelink transmission from the first group. That is, UE 115 can first select from available resources 410 in time slots 415 that have no reserved resources 405. If the first group is not empty (e.g., there is at least one time slot without any reserved resources), then UE 115 can select resources from the first group. In some cases, UE 115 can select randomly from the first group. For example, when selecting resources within the first group, each resource within the group may have an equal probability of being selected. If the first group is empty, then UE 115 can select resources from the second group.

[0117] In some cases, UE 115 can select from all available resources 410 within the COT or resource selection window 420, but some resources may have a higher probability of being selected. For example, when selecting resources for sidelink transmission, available resources 410 in the first group may have a higher probability of being selected than available resources 410 in the second group. For example, a first selection probability or weighting factor may be applied to the first group, and a second selection probability or weighting factor less than the first selection probability may be applied to the second group. In some cases, the first selection probability may be greater than 1, and the second selection probability may be less than one.

[0118] As an example of biased resource selection, there can be N resources in the first group and M resources in the second group. Therefore, there are M+N available resources to choose from. In random resource selection, each resource can have... The resources are selected with equal probability. In biased resource selection, a weighting factor W is used to determine the resource selection probability. A and W B It can be applied to the first group and the second group respectively, where W A ≠W B And W A >1>W B The available resource 410 in the first group may have a probability of being selected. The available resource 410 in the second group may have a probability of being selected. In some cases, the weighting factor can be chosen to satisfy...

[0119] In the second example, UE 115 can prioritize available resources 410 in an earlier time slot 415 of the COT or resource selection window 420. For example, UE 115 can determine a sub-selection window 425 or a high-priority window. Available resources 410 within the sub-selection window 425 can be prioritized for resource selection. For example, UE 115 can select resources from the available resources 410 within the sub-selection window 425. In some cases, UE 115 can randomly select resources from the available resources 410 within the sub-selection window 425. The sub-selection window 425 can be a subset of the COT or resource selection window 420. For example, the duration of the sub-selection window 425 can be less than the duration of the COT or resource selection window 420.

[0120] In some examples, UE 115 can choose between available resources 410 within sub-selection window 425 and resources outside sub-selection window 425, but available resources 410 within sub-selection window 425 may be given priority. For example, as described above, the first group may include available resources 410 within sub-selection window 425, and the second group may include available resources 410 outside sub-selection window 425. In some cases, the first group may include available resources 410 that appeared earlier in the COT or selection window than available resources 410 in the second group. In some cases, UE 115 may apply a first selection probability to the first group (e.g., the weighting factor W as described above). A And apply the second selection probability to the second group (e.g., the weighting factor W as described above). B ).

[0121] In some cases, the starting position of the sub-selection window can be based on the packet arrival timeline or packet readiness timeline of UE 115. In other cases, these timelines can be based on the UE processing speed. For example, if UE 115 has packets ready to be transmitted in time slot n (e.g., time slot 415-a), then the sub-selection window 425 can start from time slot n+1 (e.g., time slot 415-b). In another example, UE 115 can identify that the first time slot 415 with available resources 410 is time slot n+k, so the sub-selection window can start from time slot n+k+1.

[0122] UE 115 can prioritize available resources 410 based on whether they are in an earlier slot in resource selection window 420, included in a slot 415 containing any unreserved resource 405, or both. For example, available resources 410 that do not have a reserved resource 405 and are in an earlier slot 415 in COT or resource selection window 420 can be prioritized for selection. In some cases, a first group may include available resources 410 in slot 415 containing any unreserved resource 405 and within sub-selection window 425. UE 115 can select from the first group, or apply selection probabilities to the first group and a second group that includes remaining available resources 410.

[0123] In some cases, UE 115 can prioritize resources based on whether UE 115 selects resources for the current transmission or a future transmission. For example, UE 115 can prioritize available resources 410 in an earlier timeslot 415 for the current transmission, and UE 115 can prioritize available resources 410 in timeslot 415 that have not been reserved for resources 405 for future transmissions. In some cases, future transmissions may include retransmissions of the current transmission.

[0124] Figure 5 An example of a process flow 500 supporting a technology for resource selection for sidelink communication in an unlicensed radio spectrum band, according to aspects of this disclosure, is illustrated. In some examples, process flow 500 may implement or be implemented by aspects of wireless communication system 100 or 200. Process flow 500 may be executed by UE 505 or UE 510 or both, and may be a reference Figure 1 and Figure 2 Examples of base station 105 or UE 115 are described. In some examples, UE 505 or UE 510 may be examples of pedestrian UEs or vehicle UEs in a V2X system.

[0125] UE 505 and UE 510 can communicate on a sidelink. UE 505 and UE 510 can support autonomous resource selection for sidelink communication. Sidelink communication can occur on unlicensed radio spectrum. Process flow 500 can support techniques for prioritizing resources after selection for sidelink communication to reduce the possibility of transmission gaps.

[0126] At 515, UE 505 can determine the resource selection priority of available resources. For example, UE 505 can determine the resource selection priority associated with available resources used for sidelink signaling in unlicensed radio spectrum bands. The resource selection priority can be determined based on resource reservation information of the available resources, the time-domain location of the available resources, or both. For example, in resource selection, a first resource among the available resources can be associated with a higher priority than a second resource among the available resources. In some examples, UE 505 can perform channel sensing, such as reference... Figure 3 A more detailed description.

[0127] In some cases, UE 505 may determine that a first time slot including a first resource is not reserved for communication on an unlicensed radio spectrum band, wherein the first resource is associated with a higher priority based on the time slot not being reserved. UE 505 may determine that a second time slot including a second resource is at least partially reserved by other devices (e.g., other UE 115 sharing the COT) for communication on an unlicensed radio spectrum band. For example, available resources in a time slot that is not at least partially reserved may be prioritized for resource selection.

[0128] In some examples, UE 505 may determine resource selection priority based on sub-selection windows or high-priority windows. For example, UE 505 may identify resource selection windows where available resources span across the window, and UE 505 may identify high-priority windows within the resource selection window. In some cases, the high-priority window may correspond to an earlier resource within the resource selection window.

[0129] At 520, UE 505 can select one or more resources from available resources for sidelink signaling based on resource selection priorities associated with the available resources. For example, UE 505 can select one or more resources based on one or more resources corresponding to time slots not reserved by other radio devices. In some cases, UE 505 can select one or more resources within a high-priority window based on one or more resources. In some examples, UE 505 can determine or assign a first selection probability to resources associated with higher priority, and determine or assign a second selection probability to resources associated with lower priority. A higher selection probability can increase the likelihood that higher-priority resources are selected (e.g., randomly selected) for sidelink communication.

[0130] At point 525, UE 505 can send sidelink signaling to UE 510. In some cases, UE 505 can perform an LBT procedure to gain access to the transport medium and send sidelink signaling. The resource selection techniques described herein can increase the likelihood that UE 505 can gain access to the channel medium to send sidelink transmissions. In some cases, the techniques described herein can also increase the likelihood that UE 505 and other UEs 505 sharing the COT reserve the channel medium for future sidelink transmissions or retransmissions.

[0131] Figure 6 A block diagram 600 of a device 605 supporting technology for resource selection for sidelink communication in an unlicensed radio spectrum band is shown according to aspects of this disclosure. Device 605 may be an example of aspects of UE 115 as described herein. Device 605 may include a receiver 610, a communication manager 615, and a transmitter 620. Device 605 may also include a processor. Each of these components may communicate with each other (e.g., via one or more buses).

[0132] Receiver 610 can receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information relating to techniques for resource selection for sidelink communication in unlicensed radio spectrum bands). The information can be transmitted to other components of device 605. Receiver 610 can be a reference. Figure 9 Examples of various aspects of the transceiver 920 are described. The receiver 610 may utilize a single antenna or a collection of antennas.

[0133] Communication manager 615 can determine resource selection priorities associated with available resources for sidelink signaling in an unlicensed radio spectrum band. These priorities can be determined based on resource reservation information of the available resources, the time-domain location of the available resources, or both, wherein in resource selection, a first resource among the available resources is associated with a higher priority than a second resource among the available resources; select one or more resources from the available resources for sidelink signaling based on the resource selection priorities associated with the available resources; and transmit sidelink signaling in the unlicensed radio spectrum band using one or more of the selected resources. Communication manager 615 can be an example of aspects of communication manager 910 described herein.

[0134] The communication manager 615 or its sub-components may be implemented in hardware, code executed by a processor (e.g., software or firmware), or any combination thereof. If implemented in code executed by a processor, the functionality of the communication manager 615 or its sub-components may be performed by a general-purpose processor, data signal processor (DSP), application-specific integrated circuit (ASIC), field-programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof, designed to perform the functions described in this disclosure.

[0135] The communication manager 615 or its subcomponents may be physically located in various locations, including distributed portions such that functions are implemented by one or more physical components at different physical locations. In some examples, according to various aspects of this disclosure, the communication manager 615 or its subcomponents may be separate and distinct components. In some examples, according to various aspects of this disclosure, the communication manager 615 or its subcomponents may be combined with one or more other hardware components, including but not limited to input / output (I / O) components, transceivers, network servers, other computing devices, one or more other components described in this disclosure, or combinations thereof.

[0136] The actions performed by the UE communication manager 615 as described herein can be implemented to achieve one or more potential advantages. One example is that UE 115 can reduce latency and improve reliability by reserving resources in the COT to reduce the likelihood of losing channel medium on unlicensed radio spectrum bands. By selecting resources to reduce the likelihood of transmission gaps in the COT, UE 115 and other UEs 115 sharing the COT are less likely to lose channel medium to another wireless device, or assume that the channel medium is unavailable due to transmission gaps. Additionally or alternatively, these techniques can improve the reliability of other wireless communication devices occupying unlicensed radio spectrum bands.

[0137] Transmitter 620 can transmit signals generated by other components of device 605. In some examples, transmitter 620 may be co-located with receiver 610 in a transceiver. For example, transmitter 620 may be a reference. Figure 9 Examples of various aspects of the transceiver 920 are described. The transmitter 620 may utilize a single antenna or a collection of antennas.

[0138] By including or configuring the communication manager 615 according to the examples described herein, the device 605 (e.g., a processor that controls or otherwise couples to the receiver 610, transmitter 620, communication manager 615, or combinations thereof) can support techniques for reduced processing, more efficient use of communication resources, and other enhancements.

[0139] Figure 7 A block diagram 700 of a device 705 supporting technology for resource selection for sidelink communication in an unlicensed radio spectrum band is shown according to aspects of this disclosure. Device 705 may be an example of aspects of device 605 or UE 115 as described herein. Device 705 may include a receiver 710, a communication manager 715, and a transmitter 735. Device 705 may also include a processor. Each of these components may communicate with each other (e.g., via one or more buses).

[0140] Receiver 710 can receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information relating to techniques for resource selection for sidelink communication in unlicensed radio spectrum bands). The information can be transmitted to other components of device 705. Receiver 710 can be a reference. Figure 9 Examples of various aspects of the transceiver 920 are described. The receiver 710 may utilize a single antenna or a collection of antennas.

[0141] Communication manager 715 may be an example of aspects of communication manager 615 as described herein. Communication manager 715 may include priority determination component 720, resource selection component 725, and sidelink communication component 730. Communication manager 715 may be an example of aspects of communication manager 910 as described herein.

[0142] Priority determination component 720 can determine a resource selection priority associated with available resources for sidelink signaling in an unlicensed radio spectrum band. This resource selection priority can be determined based on resource reservation information of the available resources, the time-domain location of the available resources, or both. In resource selection, a first resource among the available resources is associated with a higher priority than a second resource among the available resources.

[0143] The resource selection component 725 can select one or more resources for sidelink signaling from available resources based on resource selection priorities associated with available resources.

[0144] The sidelink communication component 730 can use one or more selected resources to transmit sidelink signaling on an unlicensed radio spectrum band.

[0145] Transmitter 735 can transmit signals generated by other components of device 705. In some examples, transmitter 735 can be co-located with receiver 710 in a transceiver. For example, transmitter 735 can be a reference. Figure 9 Examples of various aspects of the transceiver 920 are described. The transmitter 735 may utilize a single antenna or a collection of antennas.

[0146] Figure 8 A block diagram 800 of a communication manager 805 according to an aspect of this disclosure is shown, which supports techniques for resource selection for sidelink communication in an unlicensed radio spectrum band. The communication manager 805 may be an example of aspects of the communication manager 615, communication manager 715, or communication manager 910 described herein. The communication manager 805 may include a priority determination component 810, a resource selection component 815, a sidelink communication component 820, a selection probability component 825, a high-priority window component 830, and a channel occupancy time component 835. Each of these components may communicate directly or indirectly with each other (e.g., via one or more buses).

[0147] Priority determination component 810 can determine a resource selection priority associated with available resources for sidelink signaling in an unlicensed radio spectrum band. This resource selection priority can be determined based on resource reservation information of the available resources, the time-domain location of the available resources, or both. In resource selection, a first resource among the available resources is associated with a higher priority than a second resource among the available resources.

[0148] In some examples, the priority determination component 810 may determine that a first time slot including a first resource is not reserved for communication on an unlicensed radio spectrum band, wherein the first resource is associated with a higher priority based on the unreservation of the time slot. In some examples, the priority determination component 810 may determine that a second time slot including a second resource is at least partially reserved by other devices for communication on an unlicensed radio spectrum band.

[0149] In some cases, resource selection priorities include at least a first priority and a second priority, wherein a resource is associated with either the first or second priority based on whether the time slot including the resource is at least partially reserved by another device, the resource's time position within the resource selection window, or a combination thereof. In some cases, a resource is associated with the first priority if the time slot including the resource is not at least partially reserved by another device, or if the resource is in an earlier position within the resource selection window, or both. In some cases, a resource is associated with the second priority if the time slot including the resource is at least partially reserved by another device, or if the resource is in a later position within the resource selection window, or both.

[0150] Resource selection component 815 can select one or more resources for sidelink signaling from available resources based on resource selection priorities associated with the available resources. In some examples, resource selection component 815 can randomly select one or more resources from resources associated with higher priorities. In some examples, resource selection component 815 can select one or more resources for sidelink signaling from available resources, wherein resources associated with higher priorities have a higher probability of being selected.

[0151] Sidelink communication component 820 can transmit sidelink signaling on an unlicensed radio spectrum band using one or more selected resources. In some cases, sidelink signaling includes a sidelink transmission and one or more retransmissions of that sidelink transmission, wherein the one or more resources are selected for the sidelink transmission and the one or more retransmissions of that sidelink transmission. In some cases, a first set of resources for the sidelink transmission is selected based on an earlier, higher priority window within the resource selection window, and a second set of resources for the one or more retransmissions of the sidelink transmission is selected based on the time slots including the second set of resources not being at least partially reserved for unlicensed radio spectrum bands by other wireless devices.

[0152] Selection probability component 825 can determine a first selection probability of a resource associated with a higher priority. In some examples, selection probability component 825 can determine a second selection probability of a resource associated with a lower priority, where the first selection probability is greater than the second selection probability. In some examples, selection probability component 825 can select one or more resources from available resources based on the first and second selection probabilities.

[0153] The high-priority window component 830 can identify resource selection windows where available resources span across the resource selection window. In some examples, the high-priority window component 830 can identify high-priority windows within resource selection windows.

[0154] In some examples, the high-priority window component 830 can determine a first selection probability for a resource associated with a higher priority within the high-priority window. In some examples, the high-priority window component 830 can determine a second selection for a resource associated with a lower priority, wherein the first selection probability is greater than the second selection probability.

[0155] In some examples, the high-priority window component 830 can select one or more resources from available resources based on a first selection probability and a second selection probability. In some examples, the high-priority window component 830 can select one or more resources from resources in a high-priority window.

[0156] In some examples, the high-priority window component 830 can determine that time slots including resources associated with higher priority have not been reserved by other radio devices for unlicensed radio spectrum bands. In some cases, the high-priority window corresponds to an earlier resource in the resource selection window. In some cases, the selection is random. In some cases, the high-priority window is based on the UE's processing speed.

[0157] The channel occupancy time component 835 can determine a resource selection window corresponding to available resources, wherein the resource selection window is determined based on the channel occupancy time configured by the UE, the base station, another UE, a roadside unit, or any combination thereof. In some cases, available resources are available within the channel occupancy time configured by the base station, the UE, or another node. In other cases, available resources span at least the channel occupancy time configured by the base station, the UE, or another node.

[0158] Figure 9 A diagram of a system 900 including a device 905 supporting resource selection for sidelink communication in an unlicensed radio spectrum band is shown according to aspects of this disclosure. Device 905 may be an example of or include components of device 605, device 705, or UE 115 as described herein. Device 905 may include components for bidirectional voice and data communication, including components for transmitting and receiving communications, including a communication manager 910, an I / O controller 915, a transceiver 920, an antenna 925, a memory 930, and a processor 940. These components may communicate electronically via one or more buses (e.g., bus 945).

[0159] The communication manager 910 can determine resource selection priorities associated with available resources for sidelink signaling in an unlicensed radio spectrum band. These resource selection priorities can be determined based on resource reservation information of the available resources, the time-domain location of the available resources, or both. In the resource selection, a first resource among the available resources is associated with a higher priority than a second resource among the available resources. Based on the resource selection priorities associated with the available resources, one or more resources for sidelink signaling are selected from the available resources. And sidelink signaling is transmitted in the unlicensed radio spectrum band using one or more of the selected resources.

[0160] The I / O controller 915 can manage the input and output signals of the device 905. The I / O controller 915 can also manage peripheral devices not integrated into the device 905. In some cases, the I / O controller 915 can represent a physical connection or port to an external peripheral device. In some cases, the I / O controller 915 can utilize an operating system, such as... Or another known operating system. In other cases, the I / O controller 915 may represent a modem, keyboard, mouse, touchscreen, or similar device, or may interact with such devices. In some cases, the I / O controller 915 may be implemented as part of a processor. In some cases, a user may interact with the device 905 via the I / O controller 915 or via hardware components controlled by the I / O controller 915.

[0161] Transceiver 920 can communicate bidirectionally via one or more antennas, wired or wireless links as described above. For example, transceiver 920 can represent a wireless transceiver and can communicate bidirectionally with another wireless transceiver. Transceiver 920 may also include a modem to modulate packets and provide the modulated packets to the antenna for transmission, and demodulate packets received from the antenna.

[0162] In some cases, a wireless device may include a single antenna 925. However, in other cases, the device may have more than one antenna 925 that may be able to transmit or receive multiple wireless transmissions simultaneously.

[0163] Memory 930 may include RAM and ROM. Memory 930 may store computer-readable, computer-executable code 935, including instructions that, when executed, cause the processor to perform the various functions described herein. In some cases, memory 930 may contain a basic input / output system (BIOS), which controls basic hardware or software operations such as interaction with peripheral components or devices.

[0164] Processor 940 may include intelligent hardware devices (e.g., general-purpose processors, DSPs, CPUs, microcontrollers, ASICs, FPGAs, programmable logic devices, discrete gate or transistor logic components, discrete hardware components, or any combination thereof). In some cases, processor 940 may be configured to use a memory controller to operate a memory array. In other cases, the memory controller may be integrated into processor 940. Processor 940 may be configured to execute computer-readable instructions stored in memory (e.g., memory 930) to cause device 905 to perform various functions (e.g., functions or tasks supporting technology for resource selection for sidelink communication in unlicensed radio spectrum bands).

[0165] Code 935 may include instructions for implementing various aspects of this disclosure, including instructions for supporting wireless communication. Code 935 may be stored in a non-transitory computer-readable medium such as system memory or other types of memory. In some cases, code 935 may not be directly executed by processor 940, but (e.g., when compiled and executed) may enable a computer to perform the functions described herein.

[0166] By including or configuring the communication manager 910 according to the examples described herein, the device 905 can support enhanced technologies such as improved communication reliability, reduced latency, and more efficient utilization of communication resources.

[0167] Figure 10 A flowchart illustrating a method 1000 for resource selection for sidelink communication in an unlicensed radio spectrum band, according to various aspects of this disclosure, is shown. Operation of method 1000 can be implemented by a UE 115 or its components as described herein. For example, operation of method 1000 can be implemented by, as referenced... Figures 6 to 9 The described communication manager is executed. In some examples, the UE can execute a set of instructions to control the UE's functional elements to perform the functions described below. Alternatively, the UE can use dedicated hardware to perform aspects of the functions described below.

[0168] At point 1005, the UE can determine a resource selection priority associated with available resources for sidelink signaling in an unlicensed radio spectrum band. This resource selection priority can be determined based on resource reservation information of the available resources, the time-domain location of the available resources, or both, wherein in resource selection, a first resource among the available resources is associated with a higher priority than a second resource among the available resources. The operation of point 1005 can be performed according to the methods described herein. In some examples, aspects of the operation of point 1005 can be derived from references... Figures 6 to 9 The described priority determines which component to execute.

[0169] At point 1010, the UE can select one or more resources from the available resources for sidelink signaling based on resource selection priorities associated with the available resources. The operation of point 1010 can be performed according to the methods described herein. In some examples, aspects of the operation of point 1010 can be derived from, as referenced... Figures 6 to 9 The resource selection component described is used for execution.

[0170] At point 1015, the UE can transmit sidelink signaling on an unlicensed radio spectrum band using one or more selected resources. The operation of point 1015 can be performed according to the methods described herein. In some examples, aspects of the operation of point 1015 can be derived from, as referenced... Figures 6 to 9 The described sidelink communication component is used to perform this.

[0171] Figure 11 A flowchart illustrating a method 1100 for resource selection techniques for sidelink communication in an unlicensed radio spectrum band, according to various aspects of this disclosure, is shown. Operation of method 1100 can be implemented by a UE 115 or its components as described herein. For example, operation of method 1100 can be achieved by, as referenced... Figures 6 to 9 The described communication manager is executed. In some examples, the UE can execute a set of instructions to control the UE's functional elements to perform the functions described below. Alternatively, the UE can use dedicated hardware to perform aspects of the functions described below.

[0172] At point 1105, the UE can determine that the first time slot, including the first resource, is not reserved for communication on an unlicensed radio spectrum band. The operation at point 1105 can be performed according to the methods described herein. In some examples, aspects of the operation at point 1105 can be derived from, as referenced... Figures 6 to 9 The described priority determines which component to execute.

[0173] At 1110, the UE can determine that the second time slot, including the second resource, is at least partially reserved by other devices for communication on an unlicensed radio spectrum band. The operation of 1110 can be performed according to the methods described herein. In some examples, aspects of the operation of 1110 can be derived from, as referenced... Figures 6 to 9 The described priority determines which component to execute.

[0174] At 1115, the UE can determine a resource selection priority associated with available resources for sidelink signaling in unlicensed radio spectrum bands. This resource selection priority can be determined based on resource reservation information of the available resources, the time-domain location of the available resources, or both, wherein a first resource is associated with a higher priority based on the time slot not being reserved. The operation of 1115 can be performed according to the methods described herein. In some examples, aspects of the operation of 1115 can be derived from, as referenced... Figures 6 to 9 The described priority determines which component to execute.

[0175] At point 1120, the UE can select one or more resources from the available resources for sidelink signaling based on resource selection priorities associated with the available resources. The operation at point 1120 can be performed according to the methods described herein. In some examples, aspects of the operation at point 1120 can be derived from, as referenced... Figures 6 to 9 The resource selection component described is used for execution.

[0176] At point 1125, the UE can transmit sidelink signaling on an unlicensed radio spectrum band using one or more selected resources. Operation of point 1125 can be performed according to the methods described herein. In some examples, aspects of operation of point 1125 can be derived from, as referenced... Figures 6 to 9 The described sidelink communication component is used to perform this.

[0177] Figure 12 A flowchart illustrating a method 1200 for resource selection for sidelink communication in an unlicensed radio spectrum band, according to various aspects of this disclosure, is shown. Operation of method 1200 can be implemented by a UE 115 or its components as described herein. For example, operation of method 1200 can be achieved by, as referenced... Figures 6 to 9 The described communication manager is executed. In some examples, the UE can execute a set of instructions to control the UE's functional elements to perform the functions described below. Alternatively, the UE can use dedicated hardware to perform aspects of the functions described below.

[0178] At 1205, the UE can determine a resource selection priority associated with available resources for sidelink signaling in an unlicensed radio spectrum band. This resource selection priority can be determined based on resource reservation information of the available resources, the time-domain location of the available resources, or both, wherein in resource selection, a first resource among the available resources is associated with a higher priority than a second resource among the available resources. The operation of 1205 can be performed according to the methods described herein. In some examples, aspects of the operation of 1205 can be derived from, as referenced... Figures 6 to 9 The described priority determines which component to execute.

[0179] At step 1210, the UE can determine the first selection probability of the resource associated with the higher priority. The operation at step 1210 can be performed according to the methods described herein. In some examples, aspects of the operation at step 1210 can be derived from, as referenced... Figures 6 to 9 The described selection probability component is used for execution.

[0180] At step 1215, the UE can determine a second selection probability for a resource associated with a lower priority, where the first selection probability is greater than the second selection probability. The operation at step 1215 can be performed according to the methods described herein. In some examples, aspects of the operation at step 1215 can be derived from, as referenced... Figures 6 to 9 The described selection probability component is used for execution.

[0181] At point 1220, the UE can select one or more resources from the available resources based on a first selection probability and a second selection probability. The operation at point 1220 can be performed according to the methods described herein. In some examples, aspects of the operation at point 1220 can be derived from, as referenced... Figures 6 to 9 The described selection probability component is used for execution.

[0182] At point 1225, the UE can use one or more selected resources to transmit sidelink signaling on an unlicensed radio spectrum band. Operation of point 1225 can be performed according to the methods described herein. In some examples, aspects of operation of point 1225 can be derived from references... Figures 6 to 9 The described sidelink communication component is used to perform this.

[0183] Figure 13 A flowchart illustrating a method 1300 for resource selection for sidelink communication in an unlicensed radio spectrum band, according to various aspects of this disclosure, is shown. Operation of method 1300 can be implemented by a UE 115 or its components as described herein. For example, operation of method 1300 can be implemented by, as referenced... Figures 6 to 9 The described communication manager is executed. In some examples, the UE can execute a set of instructions to control the UE's functional elements to perform the functions described below. Alternatively, the UE can use dedicated hardware to perform aspects of the functions described below.

[0184] At point 1305, the UE can identify a resource selection window, where available resources span across the window. Operation at point 1305 can be performed according to the methods described herein. In some examples, aspects of operation at point 1305 can be derived from, as referenced... Figures 6 to 9 The high-priority window component described is used for execution.

[0185] At point 1310, the UE can identify high-priority windows within the resource selection window. The operation at point 1310 can be performed according to the methods described herein. In some examples, aspects of the operation at point 1310 can be derived from references... Figures 6 to 9 The high-priority window component described is used for execution.

[0186] At 1315, the UE can determine a resource selection priority associated with available resources for sidelink signaling in an unlicensed radio spectrum band. This resource selection priority can be determined based on resource reservation information of the available resources, the time-domain location of the available resources, or both, wherein in resource selection, a first resource among the available resources is associated with a higher priority than a second resource among the available resources. The operation of 1315 can be performed according to the methods described herein. In some examples, aspects of the operation of 1315 can be derived from references... Figures 6 to 9 The described priority determines which component to execute.

[0187] At 1320, the UE can select one or more resources from the available resources for sidelink signaling based on resource selection priorities associated with the available resources. The operation at 1320 can be performed according to the methods described herein. In some examples, aspects of the operation at 1320 can be derived from, as referenced... Figures 6 to 9 The resource selection component described is used for execution.

[0188] At point 1325, the UE can use one or more selected resources to transmit sidelink signaling on an unlicensed radio spectrum band. Operation of point 1325 can be performed according to the methods described herein. In some examples, aspects of operation of point 1325 can be derived from, as referenced... Figures 6 to 9 The described sidelink communication component is used to perform this.

[0189] It should be noted that the methods described herein are examples of possible solutions, and the operations and steps can be rearranged or otherwise modified, and other examples are possible. Furthermore, two or more aspects from the methods can be combined.

[0190] The following provides an overview of the various aspects of this disclosure:

[0191] Aspect 1: A method for wireless communication at a UE, comprising: determining a resource selection priority associated with available resources for sidelink signaling in an unlicensed radio spectrum band, the resource selection priority being determined at least in part based on resource reservation information of the available resources, a time-domain location of the available resources, or both, wherein in the resource selection, a first resource among the available resources is associated with a higher priority than a second resource among the available resources; selecting one or more resources for sidelink signaling from the available resources based at least in part on the resource selection priority associated with the available resources; and transmitting the sidelink signaling in the unlicensed radio spectrum band using the one or more selected resources.

[0192] Aspect 2: According to the method of Aspect 1, wherein determining the resource selection priority includes: determining that a first time slot including a first resource is not reserved for communication on an unlicensed radio spectrum band, wherein the first resource is associated with a higher priority at least in part based on the fact that the time slot is not reserved; and determining that a second time slot including a second resource is at least in part reserved by other devices for communication on an unlicensed radio spectrum band.

[0193] Aspect 3: The method according to any one of Aspects 1 to 2, wherein selecting the one or more resources includes: randomly selecting the one or more resources from those associated with the higher priority.

[0194] Aspect 4: The method according to any one of Aspects 1 to 3, wherein selecting the one or more resources includes: selecting the one or more resources for the sidelink signaling from the available resources, wherein the resource associated with the higher priority has a higher probability of being selected.

[0195] Aspect 5: The method according to any one of Aspects 1 to 4, wherein selecting the one or more resources includes: determining a first selection probability of the resource associated with the higher priority; determining a second selection probability of the resource associated with the lower priority, wherein the first selection probability is greater than the second selection probability; and selecting one or more resources from available resources based at least in part on the first selection probability and the second selection probability.

[0196] Aspect 6: The method according to any one of Aspects 1 to 5, wherein determining the resource selection priority includes: identifying a resource selection window, wherein the available resource spans the resource selection window; and identifying a high-priority window within the resource selection window.

[0197] Aspect 7: According to the method of aspect 6, wherein the high priority window corresponds to the earlier resource in the resource selection window.

[0198] Aspect 8: The method according to any one of Aspects 6 to 7, wherein selecting the one or more resources includes: determining a first selection probability of a resource associated with a higher priority in a high priority window; determining a second selection of a resource associated with a lower priority, wherein the first selection probability is greater than the second selection probability; and selecting one or more resources from available resources based at least in part on the first selection probability and the second selection probability.

[0199] Aspect 9: The method according to any one of Aspects 6 to 8, wherein selecting the one or more resources includes: selecting the one or more resources from the resources in the high priority window.

[0200] Aspect 10: According to the method of aspect 9, where the selection is random.

[0201] Aspect 11: The method of any one of Aspects 6 to 10, wherein the high priority window is based at least in part on the processing speed of the UE.

[0202] Aspect 12: The method according to any one of aspects 6 to 11 further includes: determining that a time slot including resources associated with the higher priority has not been reserved by other wireless devices for the unlicensed radio spectrum band.

[0203] Aspect 13: The method according to any one of aspects 1 to 12 further includes: determining a resource selection window corresponding to the available resource, wherein the resource selection window is determined at least in part based on channel occupancy time configured by the UE, the base station, another UE, the roadside unit, or any combination thereof.

[0204] Aspect 14: The method according to any one of Aspects 1 to 13, wherein the resource selection priority includes at least a first priority and a second priority, and is based at least in part on whether the time slot of the resource is at least partially reserved by another device, the time position of the resource within the resource selection window, or a combination thereof, and the resource is associated with the first priority or the second priority.

[0205] Aspect 15: According to the method of aspect 14, the resource is associated with the first priority if the time slot including the resource is not at least partially reserved by another device or if the resource is earlier in the resource selection window or both.

[0206] Aspect 16: According to the method of any one of Aspects 14 to 15, wherein the resource is associated with a second priority if the time slot including the resource is at least partially reserved by another device or if the resource is later in the resource selection window or both.

[0207] Aspect 17: The method according to any one of Aspects 1 to 16, wherein the sidelink signaling includes a sidelink transmission and one or more retransmissions of the sidelink transmission, wherein the one or more resources are selected for the sidelink transmission and the one or more retransmissions of the sidelink transmission.

[0208] Aspect 18: According to the method of aspect 17, the first resource set for sidelink transmission is selected at least in part based on an earlier high-priority window within the resource selection window, and the second resource set for one or more retransmissions for sidelink transmission is selected at least in part based on time slots including a second resource set that has not been at least partially reserved by other wireless devices for unlicensed radio spectrum bands.

[0209] Aspect 19: The method according to any one of Aspects 1 to 18, wherein the available resources are available during a channel occupancy time configured by the base station, the UE, or another node.

[0210] Aspect 20: The method according to any one of Aspects 1 to 19, wherein the available resources span at least the channel occupancy time configured by the base station, the UE, or another node.

[0211] Aspect 21: An apparatus for wireless communication at a UE, comprising: a processor; a memory coupled to the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform the method of any one of aspects 1 to 20.

[0212] Aspect 22: An apparatus for wireless communication at a UE, comprising at least one component for performing a method according to any one of aspects 1 to 20.

[0213] Aspect 23: A non-transitory computer-readable medium storing code for wireless communication at a UE, the code including instructions executable by a processor to perform a method according to any one of aspects 1 to 20.

[0214] While aspects of LTE, LTE-A, LTE-A Pro, or NR systems may be described for illustrative purposes, and the terms LTE, LTE-A, LTE-A Pro, or NR may be used in many descriptions, the techniques described herein are applicable beyond LTE, LTE-A, LTE-A Pro, or NR networks. For example, the described techniques can be applied to a variety of other wireless communication systems, such as Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM, and other systems and radio technologies not explicitly mentioned herein.

[0215] The information and signals described herein can be represented using any of a variety of different techniques and skills. For example, the data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the description can be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, light fields or light particles, or any combination thereof.

[0216] The various illustrative blocks and components described in connection with this disclosure can be implemented or executed using a general-purpose processor, DSP, ASIC, CPU, FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware component, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but alternatively, the processor may be any processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors combined with a DSP core, or any other such configuration).

[0217] The functions described herein can be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions can be stored on or transmitted via a computer-readable medium as one or more instructions or code. Other examples and implementations are within the scope of this disclosure and the appended claims. For example, due to the nature of software, the functions described herein can be implemented using software executed by a processor, hardware, firmware, hardwiring, or any combination thereof. Features implementing the functions can also be physically located in various locations, including being distributed such that portions of the functions are implemented at different physical locations.

[0218] Computer-readable media includes both non-transitory computer storage media and communication media, with the latter including any medium that facilitates the transfer of a computer program from one location to another. Non-transitory storage media can be any available medium accessible by a general-purpose or special-purpose computer. By way of example, and not limitation, non-transitory computer-readable media can include random access memory (RAM), read-only memory (ROM), electrically erasable programmable ROM (EEPROM), flash memory, compact disc (CD) ROM or other optical disc storage, magnetic disk storage or other magnetic storage devices, or any other non-transitory medium that can be used to carry or store desired program code in the form of instructions or data structures and is accessible by a general-purpose or special-purpose computer or a general-purpose or special-purpose processor. Furthermore, any connection is appropriately referred to as computer-readable media. For example, if software is transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of computer-readable media. As used herein, discs and platters include CDs, laser discs, optical discs, digital multifunction discs (DVDs), floppy disks, and Blu-ray discs, where discs typically reproduce data magnetically, while platters optically reproduce data using lasers. Combinations of these are also included within the scope of computer-readable media.

[0219] As used herein, "or" includes in the claims, and as in a list of items (e.g., a list of items beginning with phrases such as "at least one of..." or "one or more of...") indicates a list of inclusion, such that a list of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C). Furthermore, as used herein, the phrase "based on" should not be construed as a reference to a closed set of conditions. For example, an example step described as "based on condition A" may be based on both condition A and condition B without departing from the scope of this disclosure. In other words, as used herein, the phrase "based on" should be interpreted in the same manner as the phrase "at least partially based on".

[0220] In the accompanying drawings, similar components or features may have the same reference numerals. Furthermore, various components of the same type can be distinguished by a dashed line following the reference numeral and a second reference numeral used to differentiate between similar components. If only the first reference numeral is used in the description, the description applies to any of the similar components having the same first reference numeral, regardless of the second reference numeral or other subsequent reference numerals.

[0221] This document describes example configurations illustrated with reference to the accompanying drawings, and does not represent all examples that can be implemented or that are within the scope of the claims. The term "example" as used herein means "serving as an example, instance, or illustration," and not "preferred" or "superior to other examples." Detailed descriptions, including specific details, are provided to provide an understanding of the described techniques. However, such techniques can be practiced without such specific details. In some instances, well-known structures and devices are shown in block diagram form to avoid obscuring the concepts of the described examples.

[0222] The description herein is provided to enable those skilled in the art to make or use this disclosure. Various modifications to this disclosure will be apparent to those skilled in the art, and the general principles defined herein may be applied to other variations without departing from the scope of this disclosure. Therefore, this disclosure is not limited to the examples and designs described herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for wireless communication at a user equipment (UE), comprising: A resource selection priority is determined for use with available resources for sidelink signaling in an unlicensed radio spectrum band. The resource selection priority is determined at least in part based on resource reservation information of the available resources, the time-domain location of the available resources, or both. In the resource selection, a first resource among the available resources is associated with a higher priority than a second resource among the available resources. And the resource in the time slot is identified as the available resource if the measured reference signal received power from the UE from the resource in the reserved time slot is less than a threshold. One or more resources for the sidelink signaling are selected from the available resources, at least in part, based on the resource selection priority associated with the available resources; as well as The sidelink signaling is transmitted using one or more selected resources on the unlicensed radio spectrum band. The resource selection priority includes at least a first priority and a second priority, wherein the resource is associated with the first priority or the second priority at least in part based on whether the time slot of the resource is at least partially reserved by another device, the time position of the resource within the resource selection window, or a combination thereof. Specifically, if the time slot including the resource is not at least partially reserved by the other device, or if the resource is in an earlier position within the resource selection window, or both, then the resource is associated with the first priority.

2. The method of claim 1, wherein determining the resource selection priority comprises: It is determined that a first time slot including the first resource is not reserved for communication on the unlicensed radio spectrum band, wherein the first resource is associated with the higher priority at least in part based on the fact that the first time slot is not reserved; as well as It is determined that the second time slot, which includes the second resource, is at least partially reserved by other devices for communication on the unlicensed radio spectrum band.

3. The method of claim 1, wherein selecting the one or more resources comprises: One or more resources are randomly selected from the resources associated with the higher priority.

4. The method of claim 1, wherein selecting the one or more resources comprises: One or more resources for the sidelink signaling are selected from the available resources, wherein the resources associated with the higher priority have a higher probability of being selected.

5. The method of claim 1, wherein selecting the one or more resources comprises: Determine the first selection probability of the resource associated with the higher priority; Determine a second selection probability for a resource associated with a lower priority, wherein the first selection probability is greater than the second selection probability; and The one or more resources are selected from the available resources, at least in part based on the first selection probability and the second selection probability.

6. The method of claim 1, wherein determining the resource selection priority comprises: Identify a resource selection window, wherein the available resources span the resource selection window; as well as Identify the high-priority windows within the resource selection window.

7. The method of claim 6, wherein the high-priority window corresponds to an earlier resource in the resource selection window.

8. The method of claim 6, wherein selecting the one or more resources comprises: Determine a first selection probability of the resource associated with the higher priority in the high priority window; Determine a second selection probability for a resource associated with a lower priority, wherein the first selection probability is greater than the second selection probability; and The one or more resources are selected from the available resources, at least in part based on the first selection probability and the second selection probability.

9. The method of claim 6, wherein selecting the one or more resources comprises: Select one or more resources from the resources in the high priority window.

10. The method of claim 9, wherein the selection is random.

11. The method of claim 6, wherein the high-priority window is at least partially based on the processing speed of the UE.

12. The method of claim 6, further comprising: It was determined that time slots containing resources associated with the higher priority were not reserved by other wireless devices for the unlicensed radio spectrum band.

13. The method according to claim 1, further comprising: A resource selection window corresponding to the available resources is determined, wherein the resource selection window is determined at least in part based on the channel occupancy time configured by the UE, the base station, another UE, the roadside unit, or any combination thereof.

14. The method of claim 1, wherein the resource is associated with the second priority if the time slot including the resource is at least partially reserved by the other device or if the resource is later in the resource selection window, or both.

15. The method of claim 1, wherein the sidelink signaling includes a sidelink transmission and one or more retransmissions of the sidelink transmission, wherein the one or more resources are selected for the sidelink transmission and the one or more retransmissions of the sidelink transmission.

16. The method of claim 15, wherein the first resource set for the sidelink transmission is selected at least in part based on an earlier high-priority window within the resource selection window, and the second resource set for the one or more retransmissions of the sidelink transmission is selected at least in part based on the fact that the time slot including the second resource set has not been at least partially reserved by other wireless devices for the unlicensed radio spectrum.

17. The method of claim 1, wherein the available resources are available during a channel occupancy period configured by the base station, the UE, or another node.

18. The method of claim 1, wherein the available resources span at least the channel occupancy time configured by the base station, the UE, or another node.

19. An apparatus for wireless communication at a user equipment (UE), comprising: processor, Memory coupled to the processor; as well as Instructions, stored in the memory and executable by the processor, enable the device to: A resource selection priority is determined for use with available resources for sidelink signaling in an unlicensed radio spectrum band. The resource selection priority is determined at least in part based on resource reservation information of the available resources, the time-domain location of the available resources, or both. In the resource selection, a first resource among the available resources is associated with a higher priority than a second resource among the available resources. And the resource in the time slot is identified as the available resource if the measured reference signal received power of the UE from the resource in the reserved time slot is less than a threshold. One or more resources for the sidelink signaling are selected from the available resources, at least in part, based on the resource selection priority associated with the available resources; as well as The sidelink signaling is transmitted using one or more selected resources on the unlicensed radio spectrum band. The resource selection priority includes at least a first priority and a second priority, wherein the resource is associated with the first priority or the second priority at least in part based on whether the time slot of the resource is at least partially reserved by another device, the time position of the resource within the resource selection window, or a combination thereof. Specifically, if the time slot including the resource is not at least partially reserved by the other device, or if the resource is in an earlier position within the resource selection window, or both, then the resource is associated with the first priority.

20. The apparatus of claim 19, wherein the instruction for determining the resource selection priority is executable by the processor to cause the apparatus to: Determining that a first time slot including the first resource is not reserved for communication on the unlicensed radio spectrum band, wherein the first resource is associated with the higher priority at least in part based on the fact that the first time slot is not reserved; and It is determined that the second time slot, which includes the second resource, is at least partially reserved by other devices for communication on the unlicensed radio spectrum band.

21. The apparatus of claim 19, wherein the instructions for selecting the one or more resources are executable by the processor to cause the apparatus to: One or more resources are randomly selected from the resources associated with the higher priority.

22. The apparatus of claim 19, wherein the instructions for selecting the one or more resources are executable by the processor to cause the apparatus to: One or more resources for the sidelink signaling are selected from the available resources, wherein the resources associated with the higher priority have a higher probability of being selected.

23. The apparatus of claim 19, wherein the instruction for selecting the one or more resources is executable by the processor to cause the apparatus to: Determine the first selection probability of the resource associated with the higher priority; Determine a second selection probability for a resource associated with a lower priority, wherein the first selection probability is greater than the second selection probability; and The one or more resources are selected from the available resources, at least in part based on the first selection probability and the second selection probability.

24. The apparatus of claim 19, wherein the instruction for determining the resource selection priority is executable by the processor to cause the apparatus to: Identify a resource selection window, wherein the available resources span the resource selection window; and Identify the high-priority windows within the resource selection window.

25. The apparatus of claim 24, wherein the high-priority window corresponds to an earlier resource in the resource selection window.

26. The apparatus of claim 24, wherein the instructions for selecting the one or more resources are executable by the processor to cause the apparatus to: Determine a first selection probability of the resource associated with the higher priority in the high priority window; Determine a second selection probability for a resource associated with a lower priority, wherein the first selection probability is greater than the second selection probability; and The one or more resources are selected from the available resources, at least in part based on the first selection probability and the second selection probability.

27. An apparatus for wireless communication at a user equipment (UE), comprising components for performing the method according to any one of claims 1 to 18.

28. A non-transitory computer-readable medium storing code for wireless communication at a user equipment (UE), the code comprising instructions executable by a processor to perform the method according to any one of claims 1 to 18.

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