Wireless communication method and device and medium

Abstract

The invention relates to a wireless communication method and device and a medium. The method includes: using a defined reference signal received power (RSRP) or a configured RSRP as an initial resource exclusion (RSRP) threshold and incrementing or decrementing the initial resource exclusion (RSRP) threshold to perform a full RSRP scan for a first time slot to determine a first resource exclusion (RSRP) threshold; selecting one or more sidelink candidate resources for sidelink transmission based on the full RSRP scan for the first time slot; and performing resource re-evaluation for the second time slot, the resource re-evaluation for the second time slot includes one or more iterations of candidate resource considerations using the first resource exclusion (RSRP) threshold from the first time slot as an initial resource exclusion (RSRP) threshold to determine a second resource exclusion (RSRP) threshold for resource selection in the second time slot.

Description

[0001] This divisional application is a divisional application with an application date of April 15, 2021, application number 202180027603.9, and invention name “Sidelink Resource Reassessment”.

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application claims the benefit of U.S. Provisional Application Serial No. 63 / 011,992, filed on April 17, 2020, entitled “Sidelink Resource Reevaluation,” and U.S. Patent Application Serial No. 17 / 230,973, filed on April 14, 2021, entitled “Sidelink Resource Reevaluation,” the entire contents of which are expressly incorporated herein by reference.

[0004] introduction

[0005] The present disclosure relates generally to communication systems and, more particularly, to sidelink communications.

[0006] Wireless communication systems are widely deployed to provide a variety of telecommunication services, such as telephony, video, data, messaging, and broadcasts. Typical wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources. Examples of such multiple-access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single-carrier frequency division multiple access (SC-FDMA) systems, and time division synchronous code division multiple access (TD-SCDMA) systems.

[0007] These multiple-access technologies have been adopted in various telecommunications standards to provide a common protocol that enables different wireless devices to communicate at the city, national, regional, and even global levels. One example telecommunications standard is 5G New Radio (NR). 5G NR is part of the continued evolution of mobile broadband, released by the 3rd Generation Partnership Project (3GPP) to address new requirements related to latency, reliability, security, scalability (e.g., scalability for the Internet of Things (IoT), and other requirements. 5G NR includes services related to enhanced mobile broadband (eMBB), massive machine-type communications (mMTC), and ultra-reliable low-latency communications (URLLC). Some aspects of 5G NR may be based on the 4G Long Term Evolution (LTE) standard. Various aspects of wireless communications may include sidelink communications between devices, such as in vehicle-to-everything (V2X) and / or other direct-to-device (D2D) communications. There is a need for further improvements in sidelink technologies. These improvements may also be applicable to other multiple-access technologies and telecommunications standards that employ them. Summary of the Invention

[0008] The following is a simplified summary of one or more aspects in order to provide a basic understanding of these aspects. This summary is not an extensive overview of all contemplated aspects and is neither intended to identify key or critical elements of all aspects nor to delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that will be presented later.

[0009] In one aspect of the present disclosure, a method of wireless communication is provided, comprising performing a full reference signal received power (RSRP) scan for a first time slot to determine a first resource exclusion RSRP threshold, and performing a resource reassessment for a second time slot based on the first resource exclusion RSRP threshold from the first time slot.

[0010] In another aspect of the present disclosure, an apparatus for wireless communication is provided, comprising: means for performing a full RSRP scan for a first time slot to determine a first resource exclusion RSRP threshold, and means for performing a resource reassessment for a second time slot based on the first resource exclusion RSRP threshold from the first time slot.

[0011] In one aspect of the present disclosure, an apparatus for wireless communication is provided. The apparatus includes a memory and at least one processor coupled to the memory, the memory and the at least one processor configured to perform a full RSRP scan for a first time slot to determine a first resource exclusion RSRP threshold. The memory and the at least one processor are configured to perform a resource reassessment for a second time slot based on the first resource exclusion RSRP threshold from the first time slot.

[0012] In one aspect of the present disclosure, a non-transitory computer-readable storage medium for wireless communication is provided. The computer-readable medium stores computer-executable code for wireless communication that, when executed by a processor, causes the processor to: perform a full RSRP scan for a first time slot to determine a first resource exclusion RSRP threshold, and perform a resource reassessment for a second time slot based on the first resource exclusion RSRP threshold from the first time slot.

[0013] In another aspect of the present disclosure, a method of wireless communication is provided. The method includes performing a full RSRP scan for a first time slot to determine a first resource exclusion RSRP threshold, and performing a full RSRP scan for a second time slot to determine a second resource exclusion RSRP threshold, wherein the second time slot is a plurality of time slots after the first time slot. For each time slot between the first time slot and the second time slot, resource reassessment may be performed based on the first resource exclusion RSRP threshold determined for the first time slot.

[0014] In another aspect of the present disclosure, an apparatus for wireless communication is provided. The apparatus includes means for performing a full RSRP scan for a first time slot to determine a first resource exclusion RSRP threshold, and performing a full RSRP scan for a second time slot to determine a second resource exclusion RSRP threshold, wherein the second time slot is a plurality of time slots after the first time slot. The apparatus also includes means for performing a resource reassessment for each time slot between the first time slot and the second time slot based on the first resource exclusion RSRP threshold determined for the first time slot.

[0015] In another aspect of the present disclosure, an apparatus for wireless communication is provided. The apparatus includes a memory and at least one processor coupled to the memory, the memory and the at least one processor being configured to: perform a full RSRP scan for a first time slot to determine a first resource exclusion RSRP threshold, and perform a full RSRP scan for a second time slot to determine a second resource exclusion RSRP threshold, wherein the second time slot is a plurality of time slots after the first time slot. The memory and the at least one processor coupled to the memory are further configured to perform a resource reassessment for each time slot between the first time slot and the second time slot based on the first resource exclusion RSRP threshold determined for the first time slot.

[0016] In another aspect of the present disclosure, a non-transitory computer-readable storage medium for wireless communication is provided. The computer-readable medium stores computer-executable code for wireless communication that, when executed by a processor, causes the processor to: perform a full RSRP scan for a first time slot to determine a first resource-exclusion RSRP threshold, and perform a full RSRP scan for a second time slot to determine a second resource-exclusion RSRP threshold, wherein the second time slot is a plurality of time slots after the first time slot. The code is further configured to cause the processor to perform a resource reassessment for each time slot between the first time slot and the second time slot based on the first resource-exclusion RSRP threshold determined for the first time slot.

[0017] To accomplish the foregoing and related ends, one or more aspects comprise the features hereinafter fully described and particularly pointed out in the claims. The following description and the accompanying drawings set forth in detail certain illustrative features of one or more aspects. However, these features are indicative of but a few of the various ways in which the principles of the various aspects may be employed, and this description is intended to include all such aspects and their equivalents. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a diagram illustrating an example of a wireless communication system and access network in accordance with various aspects presented herein.

[0019] Figure 2Example aspects of a sidelink slot structure are shown.

[0020] Figure 3 is a diagram illustrating an example of a first device and a second device involved in wireless communication based on, for example, sidelink communication, according to various aspects presented herein.

[0021] Figure 4 Example aspects of sidelink communications between devices according to aspects presented herein are shown.

[0022] Figure 5 An example of resource reservation for sidelink communication is shown.

[0023] Figure 6 An example of resource reservation for sidelink communication is shown.

[0024] 7A to 7C An example of resource reassessment according to aspects presented herein is shown.

[0025] Figure 8 is an example flow chart of a wireless communication method that includes resource reassessment using a resource exclusion RSRP threshold determined in a previous time slot.

[0026] Figure 9 is an example flow chart of a wireless communication method that includes resource reassessment using a resource exclusion RSRP threshold determined in a previous time slot.

[0027] Figure 10 is a diagram illustrating an example of a hardware implementation for an example apparatus. DETAILED DESCRIPTION

[0028] The specific embodiments described below in conjunction with the accompanying drawings are intended to serve as descriptions of various configurations and are not intended to represent only configurations that can practice the concepts described herein. In order to provide a thorough understanding of the various concepts, the specific embodiments include specific details. However, it will be apparent to those skilled in the art that these concepts can be practiced without these specific details. In some cases, well-known structures and components are shown in block diagram form to avoid obscuring these concepts.

[0029] Several aspects of telecommunications systems will now be presented with reference to various apparatuses and methods. These apparatuses and methods are described in the following detailed description and illustrated in the accompanying drawings by various modules, components, circuits, processes, algorithms, etc. (collectively, "elements"). These elements can be implemented using electronic hardware, computer software, or any combination thereof. Whether these elements are implemented as hardware or software depends on the specific application and the design constraints imposed on the overall system.

[0030] For example, an element or any part of an element, or any combination of elements, can be implemented as a "processing system" that includes one or more processors. Examples of processors include microprocessors, microcontrollers, graphics processing units (GPUs), central processing units (CPUs), application processors, digital signal processors (DSPs), reduced instruction set computing (RISC) processors, systems on a chip (SOCs), baseband processors, field programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gating logic, discrete hardware circuits, and other suitable hardware configured to perform the various functions described throughout this disclosure. One or more processors in a processing system can execute software. Software should be broadly interpreted to mean instructions, instruction sets, codes, code segments, program codes, programs, subroutines, software components, applications, software applications, software packages, routines, subroutines, objects, executable files, execution threads, processes, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or other.

[0031] Thus, in one or more examples, the functions described may be implemented in hardware, software, or any combination thereof. If implemented in software, the functions may be stored or encoded as one or more instructions or codes on a computer-readable medium. Computer-readable media include computer storage media. Storage media can be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media may include random access memory (RAM), read-only memory (ROM), electrically erasable programmable ROM (EEPROM), optical disk storage, magnetic disk storage or other magnetic storage devices, combinations of the foregoing types of computer-readable media, or any other medium that can be used to store computer-executable code in the form of instructions or data structures that can be accessed by a computer.

[0032] While various aspects and implementations are described herein through the use of a few examples, those skilled in the art will appreciate that additional implementations and use cases can be realized in many different arrangements and scenarios. The innovations described herein can be implemented across many different platform types, devices, systems, shapes, sizes, and packaging arrangements. For example, implementations and / or uses can be realized via integrated chip implementations and other non-module component-based devices (e.g., end-user devices, vehicles, communications devices, computing devices, industrial equipment, retail / procurement equipment, medical devices, artificial intelligence (AI)-enabled devices, etc.). While some examples may or may not be specifically targeted at use cases or applications, the described innovations may have a wide variety of applicability. Implementations can range from chip-level or modular components to non-modular, non-chip-level implementations, and further to aggregated, distributed, or original equipment manufacturer (OEM) devices or systems incorporating one or more aspects of the described innovations. In some practical settings, devices incorporating the described aspects and features may also include additional components and features for implementing and practicing the claimed and described aspects. For example, the transmission and reception of wireless signals must include several components for both analog and digital purposes (e.g., hardware components including antennas, RF chains, power amplifiers, modulators, buffers, processors, interleavers, adders / summers, etc.). It is intended that the innovations described herein can be practiced in a variety of devices, chip-level components, systems, distributed arrangements, end-user devices, etc., having various sizes, shapes, and configurations.

[0033] In some aspects, sidelink resource selection may be based on sensing to maintain a set of candidate resources that a UE or other wireless device can select for sidelink transmission. As part of this sensing, the UE may monitor resource reservations by other UEs. The UE may perform signal / channel measurements on sidelink resources that have been reserved and / or used by other UEs. An example of a signal / channel measurement is reference signal received power (RSRP). As an example, the UE may measure the RSRP of a received message (e.g., SCI) reserving sidelink resources. Based at least in part on the signal / channel measurements, the UE may consider using / reusing sidelink resources that have been reserved by other UEs. For example, if the measured RSRP reaches or exceeds a threshold, the UE may exclude the reserved resource from the candidate resource set. If the measured RSRP of the message reserving the resource is below the threshold, the UE may consider the reserved resource available. The UE may include the resource in the candidate resource set and may use / reuse the reserved resource if the message reserving the resource has an RSRP below the threshold, as the low RSRP indicates that the other UE is distant and that reusing the resource is unlikely to cause interference to the UE. The UE may perform resource reassessment, for example, in conjunction with retransmitting resources. If the UE performs resource reassessment on each time slot, overlapping resources reserved by other UEs may be quickly detected (e.g., upon receipt of an SCI), and the UE may be able to quickly react to updated channel occupancy. Resource reassessment performed on a per time slot basis may reduce latency and / or improve reliability by increasing the UE's ability to select resources with less interference. The calculations for per-time slot resource reassessment may involve multiple iterations of candidate resource considerations to determine an appropriate RSRP threshold for determining a set of candidate resources, thereby increasing throughput at the wireless device. A "full RSRP scan" or "complete RSRP scan" may refer to excluding the RSRP threshold from the initial resource (e.g., ) The process of starting and adjusting the resource exclusion RSRP threshold until the candidate set includes a threshold percentage of the total resources. If the UE has multiple transport blocks to send, the UE may run multiple resource re-evaluations per slot.

[0034] Various aspects presented herein enable a wireless device to perform more frequent resource reassessments, such as on a per-time slot basis, while reducing processing by the UE. The present disclosure provides for a UE to perform a full RSRP scan for a first time slot to determine a first resource exclusion RSRP threshold, and subsequently perform a resource reassessment for a second time slot based on the first resource exclusion RSRP threshold from the first time slot. By using the resource exclusion RSRP threshold for a previous time slot instead of performing a full RSRP scan, the UE can reduce the amount of processing required to reassess resources for the time slot. The more frequent resource reassessments of the present disclosure, combined with more efficient processing using the resource exclusion RSRP threshold from the previous time slot, provide improved latency and reliability.

[0035] Figure 1 is a diagram illustrating an example of a wireless communication system and access network 100 including devices configured to perform resource reassessment aspects described herein. In some aspects, a UE 104, an RSU 107, and / or other device communicating over a sidelink may include a resource reassessment component 198 configured to: perform a full RSRP scan for a first time slot to determine a first resource exclusion RSRP threshold, select a sidelink resource for transmission, and perform resource reassessment for a second time slot based on the first resource exclusion RSRP threshold from the first time slot. Performing resource reassessment using the resource exclusion RSRP threshold from a previous time slot may reduce the number of iterations performed by the UE and may reduce the processing required in each time slot. In some examples, the resource reassessment component 198 may be configured to perform a full RSRP scan in a third time slot of a plurality of time slots subsequent to the first time slot.

[0036] In some aspects, the resource reassessment component 198 can be configured to: perform a full RSRP scan for a first time slot to determine a first resource exclusion RSRP threshold, and perform a full RSRP scan for a second time slot that is a plurality of time slots after the first time slot to determine a second resource exclusion RSRP threshold. The memory and at least one processor coupled to the memory are further configured to: perform resource reassessment for each time slot between the first time slot and the second time slot based on the first resource exclusion RSRP threshold determined for the first time slot.

[0037] Some wireless communications may be sidelink-based and may include direct transmissions between wireless devices. Some wireless communication networks may include vehicle-based communication devices that may communicate from vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I) (e.g., from a vehicle-based communication device to a road infrastructure node such as a roadside unit (RSU)), vehicle-to-network (V2N) (e.g., from a vehicle-based communication device to one or more network nodes such as a base station), vehicle-to-pedestrian (V2P), cellular vehicle-to-everything (C-V2X), and / or combinations thereof and / or with other devices, which may be collectively referred to as vehicle-to-anything (V2X) communications. Again referring to Figure 1 In certain aspects, a UE 104 (e.g., a transmitting vehicle user equipment (VUE) or other UE) can be configured to send messages directly to another UE 104. This communication can be based on V2X or other D2D communications, such as proximity services (ProSe). V2X and / or D2D-based communications can also be sent and received by other transmitting and receiving devices (such as roadside units (RSUs) 107). Aspects of the communication can be based on PC5 or sidelink communications, for example, as combined with Figure 2 Although the following description may provide examples of V2X / D2D communications in conjunction with 5G NR, the concepts described herein are applicable to other similar areas such as LTE, LTE-A, CDMA, GSM, and other wireless technologies.

[0038] Figure 1 The wireless communication system and access network 100 (also known as a wireless wide area network (WWAN)) in

[15] includes a base station 102, a UE 104, an evolved packet core (EPC) 160, and a core network (e.g., 5GC) 190. Base stations 102 may include macro cells (high-power cellular base stations) and / or small cells (low-power cellular base stations). Macro cells include base stations. Small cells include femto cells, pico cells, and micro cells.

[0039] Base stations 102 configured for 4G LTE (collectively referred to as the Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN)) can interface with the EPC 160 via a backhaul link 132 (e.g., an S1 interface). Base stations 102 configured for NR (collectively referred to as the Next Generation RAN (NG-RAN)) can interface with the core network 190 via a backhaul link 184. Among other functions, the base stations 102 can perform one or more of the following: transmission of user data, radio channel encryption and decryption, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity), inter-cell interference coordination, connection establishment and release, load balancing, distribution of non-access stratum (NAS) messages, NAS node selection, synchronization, radio access network (RAN) sharing, multimedia broadcast multicast service (MBMS), subscriber and device tracking, RAN information management (RIM), paging, positioning, and delivery of warning messages. Base stations 102 may communicate with each other directly or indirectly (eg, through EPC 160 or core network 190) via backhaul links 134 (eg, an X2 interface). Backhaul links 134 may be wired or wireless.

[0040] Base stations 102 can communicate wirelessly with UEs 104. Each of base stations 102 can provide communication coverage for a corresponding geographic coverage area 110. Overlapping geographic coverage areas 110 may exist. For example, a small cell 102′ can have a coverage area 110′ that overlaps with the coverage area 110 of one or more macro base stations 102. A network that includes both small cells and macro cells may be referred to as a heterogeneous network. A heterogeneous network may also include Home evolved Node Bs (eNBs) (HeNBs), which can provide service to a restricted group known as a Closed Subscriber Group (CSG). The communication link 120 between base station 102 and UE 104 may include uplink (UL) (also known as reverse link) transmissions from UE 104 to base station 102 and / or downlink (DL) (also known as forward link) transmissions from base station 102 to UE 104. Communication link 120 may utilize multiple-input and multiple-output (MIMO) antenna technology, including spatial multiplexing, beamforming, and / or transmit diversity. The communication link may be over one or more carriers. Base station 102 / UE 104 can use spectrum with up to Y MHz (e.g., 5, 10, 15, 20, 100, 400, etc. MHz) of bandwidth per carrier allocated in carrier aggregation for a total of up to Yx MHz (x component carriers) for transmission in each direction. The carriers may be adjacent or non-adjacent. The allocation of carriers can be asymmetric with respect to DL and UL (e.g., more or fewer carriers can be allocated for DL compared to UL). Component carriers can include a primary component carrier and one or more secondary component carriers. The primary component carrier can be referred to as a primary cell (PCell), while the secondary component carriers can be referred to as secondary cells (SCells).

[0041] Certain UEs 104 may communicate with each other using device-to-device (D2D) communication links 158. D2D communication links 158 may utilize the DL / UL WWAN spectrum. D2D communication links 158 may utilize one or more sidelink channels, such as a physical sidelink broadcast channel (PSBCH), a physical sidelink discovery channel (PSDCH), a physical sidelink shared channel (PSSCH), and a physical sidelink control channel (PSCCH). D2D communication may be performed using various wireless D2D communication systems, such as, for example, FlashLinQ, WiMedia, Bluetooth, ZigBee, Wi-Fi based on the IEEE 802.11 standard, LTE, or NR.

[0042] The wireless communication system may also include a Wi-Fi access point (AP) 150 that communicates with a Wi-Fi station (STA) 152 via a communication link 154 in the 5 GHz unlicensed spectrum. When communicating in the unlicensed spectrum, the STA 152 / AP 150 may perform a clear channel assessment (CCA) to determine whether the channel is available before communicating.

[0043] The small cell 102' can operate in licensed and / or unlicensed spectrum. When operating in the unlicensed spectrum, the small cell 102' can employ NR and use the same 5 GHz unlicensed spectrum used by the Wi-Fi AP 150. The small cell 102' employing NR in the unlicensed spectrum can improve coverage and / or increase capacity of the access network.

[0044] The electromagnetic spectrum is typically subdivided into various categories, bands, channels, and so on, based on frequency / wavelength. In 5G NR, two initial operating bands have been identified as frequency ranges designated FR1 (410 MHz–7.125 GHz) and FR2 (24.25 GHz–52.6 GHz). Although a portion of FR1 is greater than 6 GHz, FR1 is often (interchangeably) referred to as the "sub-6 GHz" band in various documents and articles. A similar naming issue sometimes arises regarding FR2, which is often (interchangeably) referred to as the "millimeter wave" band in documents and articles, although it is different from the extremely high frequency (EHF) band (30 GHz–300 GHz), which is designated as the "millimeter wave" band by the International Telecommunication Union (ITU).

[0045] Frequencies between FR1 and FR2 are often referred to as mid-band frequencies. Recent 5G NR research has identified operating bands within these mid-band frequencies as frequency range designation FR3 (7.125 GHz-24.25 GHz). Frequency bands falling within FR3 can inherit FR1 characteristics and / or FR2 characteristics, effectively extending the characteristics of FR1 and / or FR2 to mid-band frequencies. Furthermore, higher frequency bands are currently being explored to extend 5G NR operation above 52.6 GHz. For example, three higher operating bands have been identified as frequency range designations FR4a or FR4-1 (52.6 GHz-71 GHz), FR4 (52.6 GHz-114.25 GHz), and FR5 (114.25 GHz-300 GHz). Each of these higher frequency bands falls within the EHF band.

[0046] With the foregoing in mind, unless otherwise specifically stated, it should be understood that the term "sub-6 GHz," etc. (if used herein) can broadly refer to frequencies that may be less than 6 GHz, may be within FR1, or may include mid-band frequencies. Furthermore, unless otherwise specifically stated, it should be understood that the term "millimeter wave," etc. (if used herein) can broadly refer to frequencies that may include mid-band frequencies, may be within FR2, FR4, FR4-a, FR4-1, and / or FR5, or may be within the EHF band.

[0047] Base station 102 (whether a small cell 102' or a large cell (e.g., a macro base station)) may include an eNB, gNodeB (gNB), or other types of base stations. Some base stations, such as gNB 180, may operate in the traditional sub-6 GHz spectrum at millimeter wave (mmW) frequencies and / or near-mmW frequencies for communicating with UE 104. When gNB 180 operates at mmW or near-mmW frequencies, gNB 180 may be referred to as a mmW base station. Extremely high frequency (EHF) is a portion of the RF spectrum in the electromagnetic spectrum. EHF ranges from 30 GHz to 300 GHz, with wavelengths between 1 mm and 10 mm. Radio waves in this band may be referred to as millimeter waves. Near-mmW may extend down to 3 GHz with a wavelength of 100 mm. The super-high frequency (SHF) band extends between 3 GHz and 30 GHz and is also known as centimeter waves. Communications using mmW / near-mmW radio frequency bands suffer from extremely high path loss and short range. The mmW base station 180 may utilize beamforming 182 with the UE 104 to compensate for the extremely high path loss and short range.

[0048] Devices can use beamforming to send and receive communications. For example, Figure 1The base station 180 is shown as being able to transmit beamformed signals in one or more transmit directions 182′ to the UE 104. The UE 104 may receive beamformed signals from the base station 180 in one or more receive directions 182″. The UE 104 may also transmit beamformed signals in one or more transmit directions to the base station 180. The base station 180 may receive beamformed signals in one or more receive directions from the UE 104. The base station 180 / UE 104 may perform beam training to determine the best receive and transmit directions for each of the base station 180 / UE 104. The transmit and receive directions of the base station 180 may be the same or different. The transmit and receive directions of the UE 104 may be the same or different. Although the beamformed signals are shown between the UE 104 and the base station 102 / 180, the UE 104 or RSU 107 may similarly apply aspects of beamforming to communicate with another UE 104 or RSU 107, such as based on V2X, V2V, or D2D communication.

[0049] The EPC 160 may include a Mobility Management Entity (MME) 162, other MMEs 164, a Serving Gateway 166, a Multimedia Broadcast Multicast Service (MBMS) Gateway 168, a Broadcast Multicast Service Center (BM-SC) 170, and a Packet Data Network (PDN) Gateway 172. The MME 162 may communicate with a Home Subscriber Server (HSS) 174. The MME 162 is a control node that handles signaling between the UE 104 and the EPC 160. Generally, the MME 162 provides bearer and connection management. All user Internet Protocol (IP) packets are transmitted through the Serving Gateway 166, which itself is connected to the PDN Gateway 172. The PDN Gateway 172 provides UE IP address allocation and other functions. The PDN Gateway 172 and the BM-SC 170 are connected to IP Services 176. IP Services 176 may include the Internet, an intranet, an IP Multimedia Subsystem (IMS), PS streaming services, and / or other IP services. The BM-SC 170 may provide functions for MBMS user service provisioning and delivery. The BM-SC 170 may serve as the entry point for content provider MBMS transmissions, may be used to authorize and initiate MBMS bearer services within a public land mobile network (PLMN), and may be used to schedule MBMS transmissions. The MBMS gateway 168 may be used to distribute MBMS services to base stations 102 belonging to a multicast broadcast single frequency network (MBSFN) area that broadcasts a specific service, and may be responsible for session management (start / stop) and collecting billing information related to eMBMS.

[0050] Core network 190 may include access and mobility management function (AMF) 192, other AMFs 193, session management function (SMF) 194, and user plane function (UPF) 195. AMF 192 may communicate with unified data management (UDM) 196. AMF 192 is a control node that handles signaling between UE 104 and core network 190. Generally, AMF 192 provides QoS flow and session management. All user Internet Protocol (IP) packets are transported through UPF 195. UPF 195 provides UE IP address allocation and other functions. UPF 195 connects to IP services 197. IP services 197 may include the Internet, intranet, IP Multimedia Subsystem (IMS), PS streaming services, and / or other IP services.

[0051] A base station may also be referred to as a gNB, Node B, evolved Node B (eNB), access point, base transceiver station, radio base station, radio transceiver, transceiver functionality, basic service set (BSS), extended service set (ESS), transmit / receive point (TRP), or some other suitable terminology. Base station 102 provides an access point to EPC 160 or core network 190 for UE 104. Examples of UE 104 include a cellular phone, smartphone, Session Initiation Protocol (SIP) phone, laptop, personal digital assistant (PDA), satellite radio, global positioning system, multimedia device, video device, digital audio player (e.g., MP3 player), camera, game console, tablet computer, smart device, wearable device, vehicle, electric meter, gas pump, large or small kitchen appliance, healthcare device, implant, sensor / actuator, display, or any other similarly functional device. Some UEs 104 may be referred to as IoT devices (e.g., parking meter, gas pump, oven, vehicle, heart monitor, etc.). UE 104 may also be referred to as a station, a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communication device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, a client, or some other suitable terminology.

[0052] Figure 2 Included are diagrams 200 and 210 illustrating example aspects of a slot structure that may be used for sidelink communications (e.g., between UE 104, RSU 107, etc.). In some examples, the slot structure may be within a 5G / NR frame structure. In other examples, the slot structure may be within an LTE frame structure. Although the following description may focus on 5G NR, the concepts described herein are applicable to other similar areas, such as LTE, LTE-A, CDMA, GSM, and other wireless technologies. Figure 2The example slot structure in FIG2 is merely an example, and other sidelink communications may have different frame structures and / or different channels for sidelink communications. A frame (10 milliseconds) may be divided into 10 equally sized subframes (1 millisecond). Each subframe may include one or more slots. A subframe may also include mini-slots, which may include 7, 4, or 2 symbols. Each slot may include 7 or 14 symbols, depending on the slot configuration. For slot configuration 0, each slot may include 14 symbols, while for slot configuration 1, each slot may include 7 symbols. Diagram 200 illustrates a single resource block for a single slot transmission, which may correspond to a 0.5 ms transmission time interval (TTI), for example. The physical sidelink control channel may be configured to occupy multiple physical resource blocks (PRBs), for example, 10, 12, 15, 20, or 25 PRBs. The PSCCH may be limited to a single subchannel. For example, the PSCCH duration may be configured to be 2 symbols or 3 symbols. For example, a subchannel may include 10, 15, 20, 25, 50, 75, or 100 PRBs. Resources for sidelink transmission may be selected from a resource pool comprising one or more subchannels. As a non-limiting example, a resource pool may include 1-27 subchannels. A PSCCH size may be established for the resource pool, for example, between 10-100% of a subchannel within a 2-symbol or 3-symbol duration. Figure 2 Diagram 210 in Figure 2 shows an example in which the PSCCH occupies approximately 50% of a subchannel, as an example to illustrate the concept of the PSCCH occupying a portion of a subchannel. The physical sidelink shared channel (PSSCH) occupies at least one subchannel. In some examples, the PSCCH may include a first portion of sidelink control information (SCI), and the PSSCH may include a second portion of the SCI.

[0053] The frame structure can be represented using a resource grid. Each time slot can include a resource block (RB) (also called a physical RB (PRB)), which extends over 12 consecutive subcarriers. The resource grid is divided into multiple resource elements (REs). The number of bits carried by each RE depends on the modulation scheme. Figure 2 As shown in , some REs may include control information in the PSCCH and some REs may include demodulation RSs (DMRSs). At least one symbol may be used for feedback. Figure 2An example is shown with two symbols for a physical sidelink feedback channel (PSFCH) with adjacent gap symbols. The symbols before and / or after the feedback can be used for turnaround between data reception and feedback transmission. The gap enables the device to switch from operating as a transmitting device to preparing to operate as a receiving device, such as in a subsequent time slot. As shown in the figure, data can be sent in the remaining REs. The data can include the data messages described herein. The location of any of the data, DMRS, SCI, feedback, gap symbols, and / or LBT symbols can be different from the Figure 2 In some examples, multiple time slots may be aggregated together.

[0054] Figure 3 Block diagram 300 illustrates a first wireless communication device 310 communicating with a second wireless communication device 350, for example, via V2X or other D2D communication. This communication can be based on a sidelink, for example, using a PC5 interface. Transmitting devices 310 and 350 may include UEs, RSUs, and the like. Packets may be provided to a controller / processor 375 that implements Layer 3 and Layer 2 functionality. Layer 3 includes the Radio Resource Control (RRC) layer, and Layer 2 includes the Packet Data Convergence Protocol (PDCP), Radio Link Control (RLC), and Medium Access Control (MAC) layers.

[0055] The transmit (TX) processor 316 and receive (RX) processor 370 implement Layer 1 functions associated with various signal processing functions. Layer 1, including the physical (PHY) layer, may include error detection on the transport channel, forward error correction (FEC) encoding / decoding of the transport channel, interleaving, rate matching, mapping to physical channels, modulation / demodulation of the physical channels, and MIMO antenna processing. The TX processor 316 handles the mapping to the signal constellation based on various modulation schemes (e.g., binary phase-shift keying (BPSK), quadrature phase-shift keying (QPSK), M-phase-shift keying (M-PSK), and M-quadrature amplitude modulation (M-QAM)). The coded and modulated symbols are then split into parallel streams. Each stream is then mapped to an OFDM subcarrier, multiplexed with a reference signal (e.g., a pilot) in the time and / or frequency domain, and then combined using an inverse fast Fourier transform (IFFT) to produce a physical channel carrying a time-domain OFDM symbol stream. The OFDM stream is spatially precoded to produce multiple spatial streams. Channel estimates from channel estimator 374 may be used to determine coding and modulation schemes, as well as for spatial processing. The channel estimates may be derived from a reference signal and / or channel condition feedback transmitted by device 350. Each spatial stream may then be provided to a different antenna 320 via a separate transmitter 318TX. Each transmitter 318TX may modulate an RF carrier with a corresponding spatial stream for transmission.

[0056] At device 350, each receiver 354RX receives a signal via its corresponding antenna 352. Each receiver 354RX recovers the information modulated onto the RF carrier and provides this information to a receive (RX) processor 356. The TX processor 368 and RX processor 356 implement Layer 1 functions associated with various signal processing functions. The RX processor 356 can perform spatial processing on this information to recover any spatial streams destined for device 350. If multiple spatial streams are destined for device 350, they can be combined into a single OFDM symbol stream by the RX processor 356. The RX processor 356 then converts the OFDM symbol stream from the time domain to the frequency domain using a fast Fourier transform (FFT). The frequency-domain signal includes a separate OFDM symbol stream for each subcarrier of the OFDM signal. By determining the most likely signal constellation point transmitted by device 310, the symbols on each subcarrier, as well as the reference signal, can be recovered and demodulated. These soft decisions can be based on the channel estimate calculated by the channel estimator 358. The soft decisions are then decoded and deinterleaved to recover the data and control signals originally sent on the physical channel by device 310. The data and control signals are then provided to a controller / processor 359, which implements layer 3 and layer 2 functionality.

[0057] The controller / processor 359 may be associated with a memory 360 that stores program codes and data. The memory 360 may be referred to as a computer-readable medium. The controller / processor 359 may provide demultiplexing between transport and logical channels, packet reassembly, decryption, header decompression, and control signal processing. The controller / processor 359 is also responsible for error detection using an ACK and / or NACK protocol to support HARQ operations.

[0058] Similar to the functions described in conjunction with the transmission of device 310, the controller / processor 359 can provide the following functions: RRC layer functions associated with system information (e.g., MIB, SIB) acquisition, RRC connection and measurement reporting; PDCP layer functions associated with header compression / decompression and security (encryption, decryption, integrity protection, integrity verification); RLC layer functions associated with transmission of upper layer PDUs, error correction through ARQ, concatenation, segmentation and reassembly of RLC SDUs, re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functions associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs to TBs, demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization.

[0059] Channel estimates derived by the channel estimator 358 from a reference signal or feedback transmitted by the device 310 may be used by the TX processor 368 to select the appropriate coding and modulation schemes and to facilitate spatial processing. The spatial streams generated by the TX processor 368 may be provided to different antennas 352 via separate transmitters 354TX. Each transmitter 354TX may modulate an RF carrier with a corresponding spatial stream for transmission.

[0060] The transmission is processed at device 310 in a manner similar to that described in conjunction with the receiver functionality at device 350. Each receiver 318RX receives a signal through its respective antenna 320. Each receiver 318RX recovers information modulated onto an RF carrier and provides the information to an RX processor 370.

[0061] The controller / processor 375 may be associated with a memory 376 that stores program codes and data. The memory 376 may be referred to as a computer-readable medium. The controller / processor 375 provides demultiplexing between transport and logical channels, packet reassembly, decryption, header decompression, and control signal processing. The controller / processor 375 is also responsible for error detection using an ACK and / or NACK protocol to support HARQ operations.

[0062] At least one of the TX processor 368, RX processor 356, or controller / processor 359 or TX 316, RX processor 370, or controller / processor 375 of the device 350 may be configured to perform a combined Figure 1 Various aspects described in the resource reassessment component 198.

[0063] Figure 4 An example 400 of wireless communication between devices based on a side link, such as V2X or other D2D communication, is shown. The communication may be based on a time slot structure. As an example, the time slot structure may include a combination of Figure 2Various aspects described. For example, UE 402 may send a transmission 414, for example, including a control channel (e.g., PSCCH) and / or a corresponding data channel (e.g., PSSCH) that may be received by UEs 404, 406, 408. The control channel may include information for decoding the data channel and may also be used by the receiving device to avoid interference by avoiding transmitting on occupied resources during data transmission. The number of TTIs and the RBs that will be occupied by the data transmission may be indicated in a control message from the transmitting device. In addition to operating as a receiving device, each of UEs 402, 404, 406, 408 may be capable of operating as a transmitting device. Thus, UEs 404, 406, 408 are shown as sending transmissions 413, 415, 416, 420. Transmissions 413, 414, 415, 416, 420 may be unicast, broadcast, or multicast to nearby devices. For example, UE 404 may transmit communications 413, 415 intended for reception by other UEs within range 401 of UE 404, and UE 406 may transmit communication 416. Additionally / alternatively, RSU 407 may receive communications from and / or transmit communications 418 to UEs 402, 404, 406, 408. One or more of UEs 402, 404, 406, 408 or RSU 407 may include, for example, a communication in conjunction with Figure 1 The resource reassessment component 198 is described.

[0064] A device communicating based on a sidelink may determine one or more radio resources in the time and frequency domains used by other devices in order to select transmission resources that avoid conflicts with other devices.

[0065] Sidelink communications can be based on different types or modes of resource allocation mechanisms. In a first resource allocation mode (which may be referred to herein as "Mode 1"), centralized resource allocation may be provided by a network entity. For example, base station 102 or 180 may determine resources for sidelink communications and allocate resources to different UEs 104 for sidelink transmissions. In this first mode, sidelink UEs receive allocations of sidelink resources from base station 102 or 180. In a second resource allocation mode (which may be referred to herein as "Mode 2"), distributed resource allocation may be provided. In Mode 2, each UE may autonomously determine resources for sidelink transmissions. To coordinate the selection of sidelink resources by individual UEs, each UE may use sensing techniques to monitor the resource reservations of other sidelink UEs and may select resources for sidelink transmissions from unreserved resources. Sidelink transmissions and / or resource reservations may be periodic or aperiodic, where a UE may reserve resources for transmissions in the current time slot and up to two future time slots (discussed below).

[0066] Thus, in a second mode (e.g., Mode 2), each device may autonomously select resources for sidelink transmission, e.g., without requiring a central entity such as a base station to indicate resources to the device. The first device may reserve the selected resources to inform other devices of the resources the first device intends to use for sidelink transmission.

[0067] In some examples, resource selection for sidelink communication can be based on a sensing-based mechanism. For example, before selecting resources for data transmission, the UE can first determine whether the resources have been reserved by other UEs.

[0068] For example, as part of a sensing mechanism for resource allocation mode 2, before selecting a sidelink resource for data transmission, the UE may determine (e.g., sense) whether the selected sidelink resource has been reserved by another UE. If the UE determines that the sidelink resource has not been reserved by another UE, the UE may transmit data using the selected sidelink resource, for example, in a PSSCH transmission. The UE may estimate or determine which radio resources (e.g., sidelink resources) may be used and / or reserved by other devices by detecting and decoding sidelink control information (SCI) transmitted by other UEs. The UE may use a sensing-based resource selection algorithm to estimate or determine which radio resources are used and / or reserved by other devices. The UE may receive SCI from another UE, the SCI including reservation information based on a resource reservation field included in the SCI. The UE may continuously monitor (e.g., sense) and decode the SCI from a peer UE. The SCI may include reservation information, such as indicating the time slots and resource blocks that a particular UE has selected for future transmissions. The UE may exclude resources used and / or reserved by other UEs from a set of candidate resources for the UE to perform sidelink transmission, and the UE may select / reserve resources for sidelink transmission from unused resources, and thus form a set of candidate resources. The UE may continuously perform sensing for an SCI with resource reservations in order to maintain a set of candidate resources, from which the UE may select one or more resources for sidelink transmission. Once the UE has selected a candidate resource, the UE may send an SCI to indicate its own reservation of resources for sidelink transmission. The number of resources (e.g., subchannels per subframe) reserved by the UE may depend on the size of the data to be sent by the UE. Although this example is described with respect to a UE receiving a reservation from another UE, a reservation may also be received from an RSU or other device communicating based on a sidelink.

[0069] Figure 55 is an example illustrating reserved time and frequency resources for sidelink transmissions. For example, the resources may be included in a sidelink resource pool. Resource allocation for each UE may be in units of one or more subchannels (e.g., subchannels SC1 to SC4) in the frequency domain and may be based on a time slot in the time domain. A UE may also use resources in the current time slot for an initial transmission and reserve resources in future time slots for retransmissions. In this example, UE1 and UE2 reserve two different future time slots for retransmissions. Resource reservation may be restricted to a predefined window of time slots and subchannels, such as the 8-slot by 4-subchannel window shown in example 500, which provides a total of 32 available resource blocks. This window may also be referred to as a resource selection window.

[0070] A first UE ("UE1") may reserve a subchannel (e.g., SC1) for its initial data transmission 502 in a current time slot (e.g., time slot 1) and may reserve additional future time slots within the window for data retransmissions (e.g., 504 and 506). For example, UE1 may reserve subchannel SC3 at time slot 3 and subchannel SC2 at time slot 4 for future retransmissions, as shown in FIG. Figure 4 UE1 then sends information about which resources it is using and / or has reserved to other UEs. UE1 may do this by including the reservation information in the reserved resources field of an SCI (eg, a first-stage SCI).

[0071] Figure 5 The second UE ("UE2") is shown reserving resources in subchannels SC3 and SC4 for its current data transmission 508 in time slot 1, and reserving a first data retransmission 510 in time slot 4 using subchannels SC3 and SC4, and a second data retransmission 512 in time slot 7 using subchannels SC1 and SC2, as shown in FIG. Figure 5 Similarly, UE2 can send resource usage and reservation information to other UEs, such as using the reserved resource field in the SCI.

[0072] The third UE may select resources for transmitting its data based on resources reserved by other UEs within the resource selection window. The third UE may first decode the SCI within a certain period of time to identify which resources are available (e.g., candidate resources). For example, the third UE may exclude resources reserved by UE1 and UE2 and select other available subchannels and time slots from the candidate resources for its transmission and retransmission, which may be based on the number of adjacent subchannels into which the data to be transmitted (e.g., a packet) can fit.

[0073] although Figure 5Resources are shown reserved for an initial transmission and two retransmissions, but the reservation may be for the initial transmission and a single transmission or for the initial transmission only.

[0074] The UE may determine an associated signal measurement (such as RSRP) for each resource reservation received by another UE. The UE may consider the reserved resources available for use by the UE in transmissions for which the UE measures an RSRP below a threshold. The UE may perform signal / channel measurements on sidelink resources already reserved and / or used by other UEs, such as by measuring the RSRP of a message reserving the sidelink resources (e.g., SCI). Based at least in part on the signal / channel measurements, the UE may consider using / reusing sidelink resources already reserved by other UEs. For example, if the measured RSRP reaches or exceeds a threshold, the UE may exclude the reserved resources from a candidate resource set, and if the measured RSRP of the message reserving the resources is below the threshold, the UE may consider the reserved resources available. The UE may include the resources in the candidate resource set and may use / reuse the reserved resources if the message reserving the resources has an RSRP below the threshold, as the low RSRP indicates that the other UE is far away and that reusing the resources is unlikely to cause interference to the UE. A higher RSRP indicates that the transmitting UE of the reserved resources is potentially closer to the UE and may experience a higher degree of interference if the UE selects the same resources.

[0075] For example, in a first step, the UE may determine a candidate resource set (e.g., by monitoring SCIs from other UEs and removing from the candidate resource set resources reserved by other UEs in signals where the RSRP measured by the UE is above a threshold). In a second step, the UE may select N resources for transmission and / or retransmission of a TB. As an example, the UE may randomly select N resources from the candidate resource set determined in the first step. In a third step, for each transmission, the UE may reserve future time and frequency resources for the initial transmission and up to two retransmissions. The UE may reserve resources by sending an SCI indicating resource reservation. For example, in Figure 5 In the example of FIG. 5 , the UE may send an SCI to reserve resources for data transmissions 508 , 510 , and 512 .

[0076] There may be a timeline for sensing-based resource selection as the UE senses and decodes SCI received from other UEs during a sensing window, e.g., the duration before resource selection during which the UE monitors or stores resource reservations from other UEs.

[0077] Based on the sensing history, the UE may be able to determine candidate resources that are available within a period of time after selection by excluding resources reserved by other UEs. Figure 6An example timing diagram 600 for resource evaluation and selection incorporating various aspects described herein is shown. Figure 6 In the example, at time t0, the first UE may select a resource from the candidate resources it has determined. There may be a time gap between the first UE's resource selection and the first UE's transmission of the SCI reserving resources at time t3 (e.g., at 602). The time gap between t1 and t3 may be used for processing by the first UE and / or transmission preparation by the first UE. The second UE may select a resource at time t2 and may have a shorter time gap between the resource selection and the transmission of the SCI 604 reserving resources. Figure 6 As shown, the second UE may send SCI 604 between the time the first UE selects resources at t0 and the time the first UE reserves resources at t3. Figure 6 The second UE is shown reserving resources that overlap with the resources selected by the first UE. The first UE may continue to sense or monitor SCIs from other UEs between resource selection at time t1 and transmission (e.g., SCI 602 transmission at t3 and / or resource transmission indicated in the SCI). The earlier SCI 604 reserves retransmission resources at 606, so that the first UE does not use overlapping resources. A longer distance between t0 and t3 may increase the likelihood that the selected resources will be subject to intervening reservation by other UEs.

[0078] A UE may perform resource reassessment, for example, when previously selected resources are reserved in the SCI for transmission from a peer UE. Figure 6 In the example embodiment, the first UE may perform resource reassessment and may perform resource reselection for retransmission resources. If the UE performs resource reassessment in each time slot, overlapping resources reserved by other UEs may be quickly detected, for example, the UE may be able to react quickly to updated channel occupancy upon receiving the SCI. Resource reassessment performed on a per time slot basis may reduce latency and / or improve reliability by increasing the ability of the UE to select resources with less interference. However, resource reassessment may be computationally expensive and may require the UE to perform a lot of processing on a per time slot basis. If the UE has multiple transport blocks to send, the UE may run multiple resource reassessments in each time slot.

[0079] Part of the computational load for resource re-evaluation is due to determining the RSRP threshold used to determine the candidate resource set. As described above, the UE can exclude resources reserved by another UE upon receiving a signal with an RSRP above a threshold. In some examples, the RSRP threshold can be based on the amount of available resources. For example, if the amount of available resources is below a threshold (e.g., below 20%) within a selection window, the UE can use an increased RSRP threshold to increase the likelihood that the UE will be able to reuse the reserved resources. Similarly, when there is a larger amount of available resources, the UE can reduce the RSRP, for example, to minimize the chance of a possible conflict.

[0080] As an example, the UE may use the initial RSRP threshold , which may be referred to herein as the initial resource exclusion RSRP threshold. If the RSRP measured by the SCI for the reserved resources is greater than , the UE may remove reserved resources that overlap with the reserved resources from the candidate set. The UE may perform a comparison with the initial resource exclusion RSRP threshold and remove resources from the candidate set for resources reserved in multiple SCIs received from one or more UEs. If the number of remaining resources in the candidate set is less than a threshold amount of the total number of resources, such as a resource idle criterion or a resource idle threshold x%, the UE may increase the resource exclusion RSRP threshold. For example, the UE may increment the RSRP threshold by a specific amount. In the example of an increment of 3 dB, the UE may increment the initial resource exclusion RSRP threshold by Increase by 3dB, that is = +3dB. If the number of remaining resources in the candidate set is still less than x% of the total resources, the UE may continue to increase the RSRP threshold, for example, = +3dB for t=0, 1, 2, 3, etc., until the number of remaining resources in the candidate set reaches or exceeds x% of the total resources The UE may stop at a threshold where the candidate set includes a threshold percentage of the total resources. Exclude RSRP threshold from initial resources The process of starting and adjusting the resource exclusion RSRP threshold until the candidate set includes a threshold percentage of the total resources may be referred to as a full RSRP scan or a complete RSRP scan.

[0081] The number of iterations required to perform a full RSRP scan may be large, especially when the network load is high. As an example, if =-99dBm, in order to obtain a candidate set with 20% of the total resources, the UE can set =-69dBm. This may involve 11 iterations using the example of incrementally increasing the resource exclusion RSRP threshold by 3dB. If the UE performs resource reassessment every time slot, the UE performs 11 iterations per time slot. The aspects presented herein enable the UE to achieve latency and reliability benefits of per-time slot resource reassessment based on more efficient computation that reduces the computational load on the UE for reassessment. As presented herein, the UE may use the results from a previous RSRP scan when performing future resource reassessments. A full RSRP scan may be performed once or in a reduced / infrequent manner. The UE may store the final resource exclusion RSRP threshold from the full RSRP scan and use the stored value to perform resource reassessment in one or more subsequent time slots. Using a previously determined resource exclusion RSRP threshold reduces the time complexity of the UE performing resource reassessment on a per-time slot basis. When the UE performs reassessment every time slot, the interference conditions may be similar to those of earlier time slots, and the UE may perform a reduced number of iterations to determine the updated resource exclusion RSRP threshold. In some examples, a single iteration may be used in a time slot.

[0082] In a first type of resource re-evaluation, the UE may have a configured or defined resource idle threshold x% and resource exclusion RSRP threshold (e.g., The resource exclusion RSRP threshold may also be referred to herein as an RSRP threshold or an RSRP exclusion upper limit.

[0083] When a new transport block arrives or is ready for transmission from the UE using the sidelink, the UE may perform a complete resource evaluation. The complete resource evaluation may be referred to as a full or complete RSRP scan. As described above, the UE may measure the RSRP for each received SCI of the reserved resource. If the measured RSRP is greater than , the UE may remove the reserved resources that overlap with the reserved resources from the candidate set. If the number of remaining resources in the candidate set is less than the resource idle threshold (x%) of the total number of resources in the candidate set, the UE may increase or increment the resource exclusion RSRP threshold. In the example of an increment of 3dB, the UE may increase the initial resource exclusion RSRP threshold by Increase by 3dB, that is = +3dB. If the number of remaining resources in the candidate set is still less than x% of the total resources, the UE may continue to increase the RSRP threshold, for example, = +Δ dB, for t=0, 1, 2, 3, etc., until the number of remaining resources in the candidate set reaches or exceeds x% of the total resources. Δ corresponds to an increment value, which may be configured, defined, etc. The UE may stop at a threshold where the candidate set includes a threshold percentage of the total resources (e.g., referred to as ).

[0084] In the next time slot, the UE re-evaluates resources starting from the final RSRP threshold of the previous time slot, for example, setting = The UE may increase the RSRP threshold, e.g. by = +Δ dB, for t=0, 1, 2, 3, etc., until the number of remaining resources in the candidate set reaches or exceeds x% of the total resources. If the percentage of remaining resources in the candidate set is not less than x%, the UE may store the current threshold as In some examples, the UE may reduce the RSRP threshold, e.g. = -ΔdB, for t=0, 1, 2, 3, etc., until the number of remaining resources in the candidate set is no less than a threshold percentage. In some examples, the threshold percentage may be x% of the total resources.

[0085] Figure 7A An example of this first type of resource reassessment is shown. Figure 7A As shown in , resource evaluation in a time slot is based on the RSRP threshold determined in the previous time slot. If traffic conditions are relatively stable, conditions may be similar between time slots. Therefore, the UE can perform reduced iterations in each time slot before reaching the final RSRP threshold for resource re-evaluation in the time slot. In some examples, the UE can perform a single iteration. Resource re-evaluation can provide the same results as performing a full RSRP scan in each time slot.

[0086] In the second type of resource reassessment, the UE may perform a complete resource reassessment including every n time slots or whenever possible from The full RSRP scan in the complete resource evaluation can provide an RSRP threshold. , the UE uses this threshold to perform resource reassessment for each time slot between the time slots in which the full RSRP scan is performed. Figure 7C Shown in time slot 1, using the starting resource exclusion RSRP threshold The full RSRP scan returns the final threshold The threshold value determined in time slot 1 is used as the starting resource exclusion RSRP threshold for resource reassessment in slots 2, 3, 4, etc. up to slot n. In slot n+1, the UE again performs the Rather than from A complete resource assessment of the full RSRP scan is performed to determine In time slot n+2, UE uses As the starting resource for resource re-evaluation, the UE shall exclude the RSRP threshold. As a starting resource the RSRP threshold is drained for slot n+3 until resource re-evaluation in slot 2n. In slot 2n+1 the UE performs a full RSRP scan again.

[0087] As an example, if n=16, then the initial resource exclusion RSRP threshold from the defined, configured ( ) complete resource assessment. In time slots 2-15, the UE may use the resource exclusion RSRP threshold determined in time slot 1 as the starting RSRP threshold for resource reassessment. The UE may increment / decrement the RSRP threshold in each time slot until the resource idle threshold x% is reached, as combined with Figure 7A However, in subsequent time slots, the UE will use the RSRP threshold determined in time slot 1 as the starting threshold.

[0088] UE can also be used in combination with Figure 7A The first type of resource reassessment described and as combined Figure 7B A combination of aspects of the second type of resource reassessment described. For example, the UE may perform a full RSRP scan as part of every n time slots (e.g., Figure 7B Time slot 1 and time slot n+1) from In the time slots between 1 and n+1, the UE uses As the starting resource for resource re-evaluation, the RSRP threshold is excluded. The UE can increase / decrement the RSRP threshold in each time slot until the resource idle threshold x% is reached, as combined with Figure 7A For example, in time slot 3, the UE may use the resources determined in time slot 2 to exclude RSRP In time slot 3, the UE can use the , and so on until time slot n+1. In time slot n+1, UE again performs the following steps including Rather than from A complete resource assessment of the full RSRP scan to determine In time slot n+2, UE uses The RSRP threshold is excluded as the starting resource for resource reassessment. The UE then returns to the first type of resource reassessment, where the starting RSRP threshold for a time slot is based on the final RSRP threshold determined in the previous time slot up to time slot 2n. In time slot 2n+1, the UE performs a full RSRP scan again.

[0089] In some examples, the UE may determine the type of resource reassessment to apply, for example, whether to apply a combination of Figure 7A The first type of description, combined Figure 7C The second type described is also applied in combination with Figure 7B The first type and combinations of the first type described.

[0090] Alternatively or additionally, the UE may receive configuration information that the UE uses to determine the type of resource reservation algorithm to be employed. In some examples, the UE may receive RRC signaling with configuration information for resource reassessment, for example, from a base station, an RSU, or a synchronized UE ("sync UE"). In some examples, the configuration may be received as part of an inter-UE RRC connection establishment or update procedure. The configuration may include a candidate resource idle threshold for resource reassessment (e.g., x%, which may be expressed as a fraction, a percentage, etc.), an initial resource exclusion RSRP (e.g., or ), the step size for resource exclusion RSRP increment or decrement (e.g., Δ), an indication of the number of slots (n) between full RSRP scans or full resource evaluations, or the type of per-slot resource re-evaluation to be employed (e.g., whether to employ a combination of Figure 7A The first type described, or the combination Figure 7C The second type described, again combined with Figure 7B Any combination of the first and second types described).

[0091] Figure 8 800 is a flow chart of a wireless communication method. The method may be performed by a wireless device communicating using a sidelink. In some examples, the method may be performed by a UE or a component of a UE (e.g., UE 104; device 310 or 350, which may include memory and may be an entire device or a component of a device; apparatus 1002). In other examples, the wireless device may include an RSU or other device that selects resources for sidelink communication. Figure 8 One or more aspects shown in the may be optional. Various implementations may include having a combination of Figure 8 The method of any combination of the described aspects enables a wireless device to re-evaluate resources in a more efficient manner in a frequent manner (such as per time slot).

[0092] At 810, the device performs a full RSRP scan for a first time slot to determine a first resource exclusion RSRP threshold. The first resource exclusion RSRP threshold may be determined using a defined RSRP or a configured RSRP as an initial resource exclusion RSRP threshold. As an example, the first resource exclusion RSRP used to perform the full RSRP scan may be Performing a full RSRP scan may include Start and increment the RSRP threshold until the candidate set is at least x% of the total resources as described above. RSRP scanning can be done by Figure 10 The RSRP scanning component 1040 of the apparatus 1002 in the embodiment of the present invention is executed. As shown at 808, the wireless device can perform a first resource evaluation for the first time slot. The resource re-evaluation can be performed by, for example, Figure 10 The method may be performed by the resource evaluation component 1044 of the apparatus 1002. At 810, a full RSRP scan may be performed for a first resource evaluation for a first time slot.

[0093] At 812, the wireless device may select one or more sidelink resources for transmission and / or retransmission, e.g., based on a full RSRP scan for the first time slot. The wireless device may select sidelink resources, e.g., as combined with Figures 4 to 6 For example, the UE may maintain a set of candidate resources and may select one or more resources from the set of candidate resources. The selection may be made, for example, by Figure 10 The side link resource selection component 1042 of the device 1002 is executed.

[0094] At 814, the wireless device performs a resource reassessment for the second time slot based on the first resource exclusion RSRP threshold from the first time slot, e.g., as combined with 7A to 7C The wireless device may determine a candidate set of potential resources by removing resources reserved by SCI received from other UEs. In determining which potential resources to remove, the wireless device may determine to remove resources reserved by SCI received for RSRP measurements that meet a threshold. Resource reassessment may be performed, for example, by Figure 10 After selecting one or more sidelink resources at 812, the UE may adjust one or more sidelink candidate resources for sidelink transmission based on the resource reassessment for the second time slot, for example, as shown at 816. The adjustment may be performed by, for example, Figure 10 The side link resource selection component 1042 of the device 1002 is executed.

[0095] Performing resource reassessment for the second time slot at 814 may include determining a second resource-exclusion RSRP threshold, for example, by incrementing or decrementing the first resource-exclusion RSRP threshold from the first time slot. For example, if the number of available candidate resources in the candidate set is below a candidate resource free threshold (e.g., x%) based on the current RSRP threshold, the wireless device may increment the RSRP threshold. If the number of available candidate resources in the candidate set is above a threshold (e.g., a specific percentage of total resources in the selection window) based on the current RSRP threshold, the wireless device may decrement the RSRP threshold. In some examples, the threshold may be the same as the threshold used to increment the RSRP threshold (e.g., x%). In other examples, the threshold used to decrement the RSRP threshold may be different from the threshold used to increment the RSRP threshold.

[0096] As shown at 816, the wireless device may store the second resource exclusion RSRP threshold for use in a subsequent time slot. Resource re-evaluation for the second time slot may use the first resource exclusion RSRP threshold as an initial resource exclusion RSRP threshold, for example, rather than using the configured or defined initial resource exclusion RSRP threshold used in the full RSRP scan. This storage may be performed, for example, by Figure 10 The RSRP threshold component 1046 of the device 1002 is executed.

[0097] During resource reassessment for the second time slot, the initial resource exclusion RSRP threshold (e.g., the first resource exclusion RSRP threshold from the first time slot) is incremented or decremented to determine the configured resource idle criteria. Then, as shown at 816, the wireless device may store the updated resource exclusion RSRP threshold for the third time slot, e.g., the incremented / decremented threshold for the second time slot. This storage may be performed, for example, by Figure 10 The RSRP threshold component 1046 of the device 1002 is executed.

[0098] In some examples, the wireless device may be configured with an algorithm for resource reassessment. For example, at 802, the wireless device may receive a configuration indicating that resource reassessment is performed using a resource exclusion RSRP threshold from a previous time slot, e.g., based on the above in conjunction with Figure 7A The configuration may also include a candidate resource idleness threshold (e.g., x%, which may be indicated as a fraction, percentage, etc.) for resource re-evaluation, an initial resource exclusion RSRP (e.g., ), or one or more of the resource exclusion RSRP increment or decrement steps. This configuration can be determined by Figure 10 The configuration component 1048 of the device 1002 receives it.

[0099] As shown at 820, the wireless device may again use the defined RSRP or configured RSRP (e.g., ) as the initial resource exclusion RSRP threshold, to perform a full RSRP scan for a third time slot that is a number of time slots after the first time slot. The full RSRP scan may be similar to the full RSRP scan described for 810. In one example, the wireless device may perform the full RSRP scan every 10 time slots. The example of 10 time slots is just one example to illustrate the concept. The concept can be applied to any number of time slots, for example, performing a full RSRP scan with a period of more than 10 time slots or less than 10 time slots. The RSRP scan may be performed by Figure 10 The RSRP scanning component 1040 of the device 1002 is executed.

[0100] As shown at 804, the wireless device may receive a configuration indicating that resource re-evaluation for time slots between the first time slot and the third time slot may be performed using a previous resource exclusion RSRP threshold from a previous time slot and that a full RSRP scan may be performed a number of time slots later using a defined RSRP or a configured RSRP as an initial resource exclusion RSRP threshold. For example, the configuration may instruct the wireless device to apply a combination of a first type of resource re-evaluation (e.g., using an initial resource exclusion RSRP threshold calculated for a previous time slot) and a second type of resource re-evaluation (e.g., performing a full RSRP scan every n time slots), such as in conjunction with Figure 7B The configuration may further include one or more of the following: the number of time slots between the first time slot and the third time slot when a full RSRP scan is to be performed, a candidate resource idle threshold for resource re-evaluation (e.g., x%, which may be indicated as a fraction, a percentage, etc.), an initial resource exclusion RSRP (e.g., ), or the step size of resource exclusion RSRP increment or decrement. This configuration can be determined by Figure 10 The configuration component 1048 of the device 1002 receives it.

[0101] In some examples, the wireless device can autonomously determine the number of time slots between the first time slot and the third time slot when performing a full RSRP scan, for example, at 806. For example, the UE can autonomously determine the periodicity for performing a full RSRP scan, rather than receiving a configured number of time slots for the periodicity in higher layer signaling or signaling from the network (e.g., in the configuration of 804). This determination can be made by Figure 10 The RSRP scanning component 1040 of the device 1002 is executed.

[0102] As shown at 818, the wireless device may perform resource reassessment for each time slot between the first time slot and the third time slot based on the previous resource exclusion RSRP threshold from the previous time slot. As described above, the wireless device uses the first resource exclusion RSRP threshold determined at 810 for the first time slot (e.g., ) to perform a resource reassessment for the second time slot at 814. The resource reassessment may be performed, for example, by Figure 10 The wireless device may then use resources from the second time slot excluding the RSRP threshold (e.g., ) (whether increasing, decreasing, or unchanged from the RSRP threshold of the first time slot) to perform resource re-evaluation for the next consecutive time slot. The wireless device may then use resources from the next time slot excluding the RSRP threshold (e.g., ), performs resource re-evaluation for subsequent consecutive time slots, and so on, until a time slot that is n time slots after the first time slot is reached, at which time the wireless device switches from Perform a full RSRP scan.

[0103] Figure 9 Flowchart 900 is a flow chart of a wireless communication method. The method may be performed by a wireless device communicating using a sidelink. In some examples, the method may be performed by a UE or a component of a UE (e.g., UE 104; device 310 or 350, which may include memory and may be an entire device or a component of a device; apparatus 1002). In other examples, the wireless device may include an RSU or other device that selects resources for sidelink communication. Figure 9 One or more aspects shown in the may be optional. Various implementations may include having a combination of Figure 9 The method of any combination of the described aspects enables a wireless device to re-evaluate resources in a more efficient manner in a frequent manner (such as per time slot).

[0104] At 906, the wireless device performs a full RSRP scan for the first time slot to determine a first resource exclusion RSRP threshold. The first resource exclusion RSRP threshold may be determined using a defined RSRP or a configured RSRP as an initial resource exclusion RSRP threshold. As an example, the first resource exclusion RSRP threshold for performing the full RSRP scan may be Performing a full RSRP scan may include Start and increment the RSRP threshold until the candidate set is at least x% of the total resources as described above. As shown at 904, the wireless device may perform a first resource evaluation for the first time slot. This resource evaluation may be performed, for example, by Figure 10The resource evaluation component 1044 of the apparatus 1002 in FIG. 906 can be performed by performing a full RSRP scan for a first resource evaluation for a first time slot. The RSRP scan can be performed by Figure 10 The RSRP scanning component 1040 of the device 1002 is executed.

[0105] At 910, the wireless device performs a full RSRP scan for a second time slot to determine a second resource exclusion RSRP threshold, wherein the second time slot is a number of time slots after the first time slot. The full RSRP scan may be similar to the full RSRP scan described for 906 (e.g., from (Start and increment the RSRP threshold until the candidate set accounts for at least x% of the total resources). In one example, the wireless device may perform this full RSRP scan every 10 time slots. The 10 time slot example is just one example to illustrate the concept. The concept can be applied to any number of time slots, for example, performing a full RSRP scan with a period of more than 10 time slots or less than 10 time slots. The RSRP scan may be performed by Figure 10 The RSRP scanning component 1040 of the device 1002 is executed.

[0106] At 908, the wireless device performs a resource reassessment for each time slot between the first time slot and the second time slot based on the first resource exclusion RSRP threshold determined for the first time slot. As a threshold for the first time slot and can be applied in each time slot between the first time slot and the second time slot. For example, if the second time slot is the 20th time slot, the wireless device can use As the initial resource exclusion RSRP threshold, resource reassessment is performed in time slots 2 to 19. At 808, performing resource reassessment for each time slot between the first time slot and the second time slot may include determining an updated resource exclusion RSRP threshold using the first resource exclusion RSRP threshold as the initial resource exclusion RSRP threshold. Resource reassessment may be performed, for example, by Figure 10 The resource assessment component 1044 of the device 1002 is executed.

[0107] In some examples, the wireless device may be configured with an algorithm for resource reassessment. For example, at 902, the wireless device may receive a configuration indicating that a full RSRP scan is to be performed after the plurality of time slots using a defined RSRP or a configured RSRP as an initial resource exclusion RSRP threshold and a first resource exclusion RSRP threshold is to be used for time slots between the first time slot and the second time slot. Thus, the wireless device may receive a configuration to use a second type of resource reassessment (e.g., performing a full RSRP scan every n time slots), as in conjunction with Figure 7CThe configuration may further include one or more of the following: the number of time slots between the first time slot and the third time slot when a full RSRP scan is to be performed, a candidate resource idle threshold for resource re-evaluation (e.g., x%, which may be indicated as a fraction, a percentage, etc.), an initial resource exclusion RSRP (e.g., ), or the step size of resource exclusion RSRP increment or decrement. This configuration can be determined by Figure 10 The configuration component 1048 of the device 1002 receives it.

[0108] Figure 10 1000 illustrates an example of a hardware implementation for an apparatus 1002. Apparatus 1002 may be a UE or another device capable of sidelink communication and includes a baseband processor 1004 (also known as a modem) coupled to an RF transceiver 1022. In some aspects, baseband processor 1004 may be a cellular baseband processor, and the RF transceiver may be a cellular RF transceiver. The apparatus may also include one or more subscriber identity module (SIM) cards 1020, an application processor 1006 coupled to a secure digital (SD) card 1008 and a screen 1010, a Bluetooth module 1012, a wireless local area network (WLAN) module 1014, a global positioning system (GPS) module 1016, and / or a power supply 1018. Baseband processor 1004 communicates with UE 104 and / or BS 102 / 180 via RF transceiver 1022. Baseband processor 1004 may include computer-readable media / memory. The computer-readable media / memory may be non-transitory. The baseband processor 1004 is responsible for general processing, including executing software stored on a computer-readable medium / memory. The software, when executed by the baseband processor 1004, causes the baseband processor 1004 to perform the various functions described above. The computer-readable medium / memory may also be used to store data that is manipulated by the baseband processor 1004 when executing the software. The baseband processor 1004 also includes a receive component 1030, a communication manager 1032, and a transmit component 1034. The communication manager 1032 includes one or more of the components shown. The components within the communication manager 1032 may be stored in the computer-readable medium / memory and / or configured as hardware within the baseband processor 1004. The baseband processor 1004 may be a component of the device 350 and may include a memory 360 and / or at least one of a TX processor 368, an RX processor 356, and a controller / processor 359. In one configuration, the apparatus 1002 may be a modem chip and include only the baseband processor 1004, while in another configuration, the apparatus 1002 may be the entire wireless device (e.g., see Figure 3 350 ) and includes additional modules of device 1002 .

[0109] The communication manager 1032 includes an RSRP scanning component 1040 configured to perform an RSRP scan to determine a resource exclusion RSRP threshold, e.g., as described in conjunction with Figure 8 and / or Figure 9 The communication manager 1032 further includes a sidelink resource selection component 1042 configured to select one or more sidelink resources for transmission or retransmission, e.g., as described in conjunction with 812. The sidelink resource selection component 1042 may be configured to maintain a set of candidate resources for sidelink transmission and adjust the sidelink candidate resources, e.g., as described in conjunction with Figure 8 As described in 812.

[0110] The communication manager 1032 also includes a resource evaluation component 1044 that is configured to perform a first resource evaluation (eg, using a full RSRP scan), for example, as described in conjunction with Figure 8 and Figure 9 The resource evaluation component 1044 is configured to perform a resource re-evaluation for the second time slot based on the first resource exclusion RSRP threshold from the first time slot, for example, as described in conjunction with Figure 8 or performing a resource reassessment for each time slot between the first time slot and the third time slot, for example, as described in conjunction with 814 of Figure 9 The resource evaluation component 1044 can be configured to perform a resource re-evaluation for each time slot between the first time slot and the third time slot based on a previous resource exclusion RSRP threshold from a previous time slot, for example, as described in conjunction with Figure 8 The communication manager 1032 may also include a determining component 1050 configured to determine the number of time slots between the first time slot and the third time slot when a full RSRP scan is performed, for example, as described in conjunction with Figure 8 As described in 806.

[0111] The communication manager 1032 may also include an RSRP threshold component 1046 configured to store an RSRP threshold for resource evaluation, such as storing a second resource exclusion RSRP threshold, for example, as described in conjunction with Figure 8 As described in 816.

[0112] The communication manager 1032 may also include a configuration component 1048 configured to receive a configuration indicating that resource reassessment is performed using a resource exclusion RSRP threshold from a previous time slot, e.g., as described in conjunction with Figure 8Configuration component 1048 may be configured to receive a configuration to perform resource reassessment for N time slots using a previous resource exclusion RSRP threshold from a previous time slot and perform a full RSRP scan after N time slots, e.g., as described in conjunction with Figure 8 Configuration component 1048 may be configured to receive a configuration to perform a full RSRP scan after N time slots and perform resource reassessment using a first resource exclusion RSRP threshold for N time slots, for example, as described in conjunction with Figure 9 As described in 902.

[0113] The apparatus 1002 may include executing Figure 8 and / or Figure 9 The components of each block of the algorithm in the flowchart can be one or more hardware components specifically configured to perform the process / algorithm, implemented by a processor configured to perform the process / algorithm, stored in a computer-readable medium for processor implementation, or some combination thereof.

[0114] In one configuration, the apparatus 1002 for wireless communication (particularly the processor 1004) may include a processor for performing a combined Figure 8 and Figure 9 The apparatus may be configured to perform any of the steps of the method described herein. The apparatus may be configured to perform the functions recited by the apparatus, including one or more components of the apparatus and / or a processing system of the apparatus. The processing system may include a TX processor 316, 368, an RX processor 370, 356, and a controller / processor 375, 359. Thus, in one configuration, the apparatus may be configured to perform the functions recited by the apparatus, including one or more components of the apparatus and / or a processing system of the apparatus. The processing system may include a TX processor 316, 368, an RX processor 370, 356, and a controller / processor 375, 359.

[0115] If the wireless device frequently re-evaluates the selected sidelink resources (e.g., per time slot), the latency and reliability of sidelink communications can be improved. The calculations for per-time slot resource re-evaluation involve significant processing by the wireless device, for example, to determine an appropriate RSRP threshold for determining a set of candidate resources due to multiple iterations of candidate resource consideration. Various aspects presented herein enable the wireless device to perform more frequent resource re-evaluations, such as on a per-time slot basis, while reducing processing by the UE. The present disclosure provides for a UE to perform a full RSRP scan for a first time slot to determine a first resource exclusion RSRP threshold, select a sidelink resource for transmission, and then perform a resource re-evaluation for a second time slot based on the first resource exclusion RSRP threshold from the first time slot. By using the resource exclusion RSRP threshold for a previous time slot instead of performing a full RSRP scan, the UE can reduce the amount of processing to re-evaluate resources for the time slot. The more frequent resource re-evaluations of the present disclosure, combined with more efficient processing by using the resource exclusion RSRP threshold from the previous time slot, provide improved latency and reliability.

[0116] The following example aspects are merely illustrative, and aspects thereof may be combined with aspects of other examples or teachings described herein without limitation thereto.

[0117] Aspect 1 is a method of wireless communication, comprising: performing a full RSRP scan for a first time slot to determine a first resource exclusion RSRP threshold; and performing a resource reassessment for a second time slot based on the first resource exclusion RSRP threshold from the first time slot.

[0118] In aspect 2, the method according to aspect 1 further includes: selecting one or more side link candidate resources for side link transmission based on a full RSRP scan for a first time slot; and adjusting one or more side link candidate resources for side link transmission based on a resource reassessment for a second time slot.

[0119] In aspect 3, the method according to aspect 1 or aspect 2 further comprises: determining a second resource exclusion RSRP threshold as part of performing resource reassessment for the second time slot; and storing the second resource exclusion RSRP threshold for use in a subsequent time slot.

[0120] In aspect 4, the method according to aspect 3 further comprises performing resource reassessment for the second time slot using the first resource exclusion RSRP threshold as an initial resource exclusion RSRP threshold.

[0121] In aspect 5, the method according to aspect 3 further includes increasing or decreasing the initial resource exclusion RSRP threshold to determine the configured resource idle criterion; and storing the updated resource exclusion RSRP threshold for the third time slot.

[0122] In aspect 6, the method according to any one of aspects 1-5 further comprises determining the first resource exclusion RSRP threshold using a defined RSRP or a configured RSRP as an initial resource exclusion RSRP threshold.

[0123] In aspect 7, the method according to any one of aspects 1-6 further comprises performing a first resource assessment for a first time slot, wherein a full RSRP scan is performed for the first resource assessment for the first time slot.

[0124] In aspect 8, the method according to any one of aspects 1-6 further includes receiving a configuration indicating that resource reassessment is performed using a resource exclusion RSRP threshold from a previous time slot, wherein the configuration further includes one or more of the following: a candidate resource idle threshold for resource reassessment, an initial resource exclusion RSRP, or a step size for increasing or decreasing the resource exclusion RSRP.

[0125] In aspect 9, the method according to any one of aspects 1-4 or 6-8 further includes performing a full RSRP scan for a third time slot that is a plurality of time slots after the first time slot using the defined RSRP or the configured RSRP as an initial resource exclusion RSRP threshold.

[0126] In aspect 10, the method according to aspect 9 further includes: receiving a configuration indicating that resource reassessment for time slots between the first time slot and the third time slot is performed using a previous resource exclusion RSRP threshold from a previous time slot and performing a full RSRP scan after the plurality of time slots using a defined RSRP or a configured RSRP as an initial resource exclusion RSRP threshold, wherein the configuration further includes one or more of the following: a number of time slots between the first time slot and the third time slot when the full RSRP scan is performed, a resource idle threshold for resource reassessment, an initial resource exclusion RSRP, or a step size for increasing or decreasing the resource exclusion RSRP.

[0127] In aspect 11, the method of aspect 9 further comprises autonomously determining a number of time slots between the first time slot and the third time slot when the full RSRP scan is performed.

[0128] In aspect 11, the method of aspect 9 further comprises performing resource reassessment for each time slot between the first time slot and the third time slot based on a previous resource exclusion RSRP threshold from a previous time slot.

[0129] Aspect 13 is an apparatus for wireless communication, comprising a memory and at least one processor coupled to the memory, the memory and the at least one processor being configured to: perform a full RSRP scan for a first time slot to determine a first resource exclusion RSRP threshold; and perform a resource reassessment for a second time slot based on the first resource exclusion RSRP threshold from the first time slot.

[0130] In aspect 14, the apparatus according to aspect 13 further comprises the memory and the at least one processor configured to perform the method according to any one of aspects 2-12.

[0131] In aspect 15, the apparatus according to aspect 13 or 14 further comprises a transceiver.

[0132] Aspect 14 is an apparatus for wireless communication, comprising: means for performing an RSRP scan for a first time slot to determine a first resource exclusion RSRP threshold; and means for performing a resource reassessment for a second time slot based on the first resource exclusion RSRP threshold from the first time slot.

[0133] In aspect 15, the apparatus according to aspect 14 further comprises means for performing the method according to any one of aspects 2-12.

[0134] In aspect 16, the apparatus according to aspect 14 or 15 further comprises a transceiver as part of the component.

[0135] Aspect 17 is a non-transitory computer-readable storage medium storing computer-executable code at a base station, which code, when executed by a processor, causes the processor to: perform a full RSRP scan for a first time slot to determine a first resource exclusion RSRP threshold; and perform a resource reassessment for a second time slot based on the first resource exclusion RSRP threshold from the first time slot.

[0136] In aspect 18, the computer-readable medium of aspect 17 further comprises code that, when executed by a processor, causes the processor to perform the method of any one of aspects 2-12.

[0137] Aspect 19 is a method of wireless communication, comprising: performing a full RSRP scan for a first time slot to determine a first resource exclusion RSRP threshold; performing a full RSRP scan for a second time slot to determine a second resource exclusion RSRP threshold, wherein the second time slot is a plurality of time slots after the first time slot; and performing a resource reassessment for each time slot between the first time slot and the second time slot based on the first resource exclusion RSRP threshold determined for the first time slot.

[0138] In aspect 20, the method of aspect 19 further comprises performing resource reassessment for each time slot between the first time slot and the second time slot including determining an updated resource exclusion RSRP threshold using the first resource exclusion RSRP threshold as an initial resource exclusion RSRP threshold.

[0139] In aspect 21, the method according to aspect 19 or aspect 20 further comprises determining the first resource exclusion RSRP threshold using a defined RSRP or a configured RSRP as an initial resource exclusion RSRP threshold.

[0140] In aspect 22, the method according to any of aspects 19-21 further comprises performing a first resource assessment for the first time slot, wherein a full RSRP scan is performed for the first resource assessment for the first time slot.

[0141] In aspect 23, the method according to any one of aspects 19-22 further includes: receiving a configuration indicating that a full RSRP scan is to be performed after the plurality of time slots using a defined RSRP or a configured RSRP as an initial resource exclusion RSRP threshold and using a first resource exclusion RSRP threshold for time slots between the first time slot and the second time slot, wherein the configuration further includes one or more of the following: a number of time slots between the first time slot and the second time slot when the full RSRP scan is performed, a resource idle threshold for resource reassessment, an initial resource exclusion RSRP, or a step size for increasing or decreasing the resource exclusion RSRP.

[0142] Aspect 29 is an apparatus for wireless communication, comprising: a memory; and at least one processor coupled to the memory, the memory and the at least one processor being configured to: perform a full RSRP scan for a first time slot to determine a first resource exclusion RSRP threshold; perform a full RSRP scan for a second time slot to determine a second resource exclusion RSRP threshold, wherein the second time slot is a plurality of time slots after the first time slot; and perform a resource reassessment for each time slot between the first time slot and the second time slot based on the first resource exclusion RSRP threshold determined for the first time slot.

[0143] In aspect 30, the apparatus according to aspect 29 further comprises the memory and the at least one processor configured to perform the method according to any one of aspects 20-29.

[0144] In aspect 31, the apparatus according to aspect 29 or aspect 30 further comprises a transceiver.

[0145] Aspect 32 is an apparatus for wireless communication, comprising: a component for performing a full RSRP scan for a first time slot to determine a first resource exclusion RSRP threshold; a component for performing a full RSRP scan for a second time slot to determine a second resource exclusion RSRP threshold, wherein the second time slot is a plurality of time slots after the first time slot; and a component for performing resource reassessment for each time slot between the first time slot and the second time slot based on the first resource exclusion RSRP threshold determined for the first time slot.

[0146] In aspect 33, the apparatus according to aspect 32 further comprises means for performing the method according to any one of aspects 20-29.

[0147] In aspect 34, the apparatus according to aspect 32 or 33 further comprises a transceiver as part of the component.

[0148] Aspect 35 is a non-transitory computer-readable storage medium storing computer-executable code at a base station, which code, when executed by a processor, causes the processor to: perform a full RSRP scan for a first time slot to determine a first resource exclusion RSRP threshold; perform a full RSRP scan for a second time slot to determine a second resource exclusion RSRP threshold, wherein the second time slot is a plurality of time slots after the first time slot; and perform a resource reassessment for each time slot between the first time slot and the second time slot based on the first resource exclusion RSRP threshold determined for the first time slot.

[0149] In aspect 36, the computer-readable medium of aspect 35 further comprises code that, when executed by a processor, causes the processor to perform the method of any one of aspects 20-29.

[0150] It should be understood that the specific order or hierarchy of blocks in the disclosed process / flowchart is illustrative of an exemplary method. Based on design preferences, it should be understood that the specific order or hierarchy of blocks in the process / flowchart can be rearranged. In addition, some blocks can be combined or omitted. The attached method claims provide elements of various blocks in an exemplary order, but are not intended to be limited to the specific order or hierarchy provided.

[0151] The preceding description is provided to enable anyone skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects. Accordingly, the claims are not intended to be limited to the aspects shown herein, but rather should be given the full scope consistent with the claim language, wherein reference to an element in the singular is not intended to mean "one and only one" (unless otherwise specified), but rather "one or more." The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any aspect described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other aspects. Unless otherwise specifically stated, the term "some" refers to one or more. Combinations such as "at least one of A, B, or C," "one or more of A, B, or C," "at least one of A, B, and C," "one or more of A, B, and C," and "A, B, C, or any combination thereof" include any combination of A, B, and / or C, and may include multiples of A, B, or C. Specifically, combinations such as "at least one of A, B, or C," "one or more of A, B, or C," "at least one of A, B, and C," "one or more of A, B, and C," and "A, B, C, or any combination thereof" can be A only, B only, C only, A and B, A and C, B and C, or A and B and C, where any such combination can include one or more members of A, B, or C. All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later become known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is expressly recited in the claims. Words such as "module," "mechanism," "element," "device," etc. are not intended to replace the word "component." Therefore, any claim element should not be construed as part-plus-function unless the element is expressly recited using the phrase "component for..."

Claims

1. A method of wireless communication, comprising: performing a full RSRP scan for the first time slot to determine a first resource exclusion RSRP threshold using a defined reference signal received power (RSRP) or a configured RSRP as an initial resource exclusion RSRP threshold and incrementing or decrementing the initial resource exclusion RSRP threshold; selecting one or more sidelink candidate resources for sidelink transmission based on the full RSRP scan for the first time slot; as well as Performing resource re-evaluation for the second time slot includes performing one or more iterations of candidate resource consideration using the first resource-exclusion RSRP threshold from the first time slot as an initial resource-exclusion RSRP threshold to determine a second resource-exclusion RSRP threshold for resource selection in the second time slot.

2. The method according to claim 1, further comprising: The one or more sidelink candidate resources for the sidelink transmission are adjusted based on the resource reassessment for the second time slot.

3. The method according to claim 1, further comprising: The second resource exclusion RSRP threshold is stored for use in a subsequent time slot.

4. The method of claim 3, wherein the initial resource exclusion RSRP threshold is incremented or decremented to determine a configured resource idle criterion, the method further comprising: The updated resource exclusion RSRP threshold for the third time slot is stored.

5. An apparatus for wireless communication at a wireless device, comprising: Memory; as well as one or more processors coupled to the memory, the one or more processors configured to cause the wireless device to: performing a full RSRP scan for the first time slot to determine a first resource exclusion RSRP threshold using a defined reference signal received power (RSRP) or a configured RSRP as an initial resource exclusion RSRP threshold and incrementing or decrementing the initial resource exclusion RSRP threshold; selecting one or more sidelink candidate resources for sidelink transmission based on the full RSRP scan for the first time slot; as well as Performing resource re-evaluation for the second time slot includes performing one or more iterations of candidate resource consideration using the first resource-exclusion RSRP threshold from the first time slot as an initial resource-exclusion RSRP threshold to determine a second resource-exclusion RSRP threshold for resource selection in the second time slot.

6. The apparatus of claim 5, wherein the one or more processors are further configured to cause the wireless device to: The one or more sidelink candidate resources for the sidelink transmission are adjusted based on the resource reassessment for the second time slot.

7. The apparatus of claim 5, wherein the one or more processors are further configured to cause the wireless device to: The second resource exclusion RSRP threshold is stored for use in a subsequent time slot.

8. A non-transitory computer-readable medium having stored thereon computer-executable code for wireless communication at a wireless device, the code, when executed by one or more processors, causing the wireless device to: performing a full RSRP scan for the first time slot to determine a first resource exclusion RSRP threshold using a defined reference signal received power (RSRP) or a configured RSRP as an initial resource exclusion RSRP threshold and incrementing or decrementing the initial resource exclusion RSRP threshold; selecting one or more sidelink candidate resources for sidelink transmission based on the full RSRP scan for the first time slot; as well as Performing resource re-evaluation for the second time slot includes performing one or more iterations of candidate resource consideration using the first resource-exclusion RSRP threshold from the first time slot as an initial resource-exclusion RSRP threshold to determine a second resource-exclusion RSRP threshold for resource selection in the second time slot.

9. The non-transitory computer-readable medium of claim 8, wherein the code, when executed by the one or more processors, further causes the wireless device to: The second resource exclusion RSRP threshold is stored for use in a subsequent time slot.

10. The non-transitory computer-readable medium of claim 8, wherein the code, when executed by the one or more processors, further causes the wireless device to: The full RSRP scan is performed for a third time slot that is a plurality of time slots after the first time slot using the defined RSRP or the configured RSRP as the initial resource exclusion RSRP threshold.

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