Method and apparatus for congestion control for NR V2X

Abstract

In one aspect, a method includes: determining, by a user equipment (UE), a CBR window for channel busy rate (CBR) measurement for one or more resources; determining, by the UE, CBR measurement values ​​for the CBR window and for one or more resources; determining, by the UE, a channel occupancy rate (CR) window based on a first number of subframes used historically for past transmissions and based on a second number of subframes used for future planned transmissions and corresponding retransmissions; and determining, by the UE, a CR value for the CR window based on subchannels used for one or more resources for the first number of subframes and based on estimated subchannels for one or more resources for the second number of subframes. In another aspect, a method includes determining the CR window based on the CBR measurement values.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefits of the following applications: U.S. patent application No. 17 / 061,543, filed on October 1, 2020, entitled “CONGESTION CONTROL FOR NR V2X,” and U.S. Provisional Patent Application No. 62 / 911,106, filed on October 4, 2019, entitled “CONGESTION CONTROL FOR NR V2X,” the entire contents of which are expressly incorporated herein by reference. Technical Field

[0003] Generally speaking, aspects of the present disclosure relate to wireless communication systems, and more particularly, aspects of the present disclosure relate to managing device-to-device communications, such as congestion control for vehicle-to-everything (V2X) in new radio (NR). Background Art

[0004] Wireless communication networks are widely deployed to provide various communication services such as voice, video, packet data, messaging, broadcasting, etc. These wireless networks can be multiple access networks that can support multiple users by sharing available network resources. Such a network (which is usually a multiple access network) supports communication for multiple users by sharing available network resources. An example of such a network is the Universal Terrestrial Radio Access Network (UTRAN). UTRAN is a radio access network (RAN) defined as a part of the Universal Mobile Telecommunications System (UMTS), a third generation (3G) mobile phone technology supported by the Third Generation Partnership Project (3GPP). Examples of multiple access network formats include code division multiple access (CDMA) networks, time division multiple access (TDMA) networks, frequency division multiple access (FDMA) networks, orthogonal FDMA (OFDMA) networks, and single carrier FDMA (SC-FDMA) networks.

[0005] A wireless communication network may include several base stations or Node Bs that can support communications for several user equipments (UEs). A UE may communicate with a base station via a downlink and an uplink. A downlink (or forward link) refers to a communication link from a base station to a UE, while an uplink (or reverse link) refers to a communication link from a UE to a base station.

[0006] The base station may send data and control information to the UE on the downlink, and / or may receive data and control information from the UE on the uplink. On the downlink, the transmission from the base station may encounter interference caused by transmission from a neighboring base station or from other wireless radio frequency (RF) transmitters. On the uplink, the transmission from the UE may encounter interference from uplink transmissions of other UEs communicating with the neighboring base station or from other wireless RF transmitters. This interference may degrade the performance on both the downlink and uplink.

[0007] As the demand for mobile broadband access continues to grow, the potential for interference and congested networks increases as more UEs access long-range wireless communication networks and more short-range wireless systems are deployed in communities. Research and development continues to advance wireless technologies, including multiple access technologies, not only to meet the growing demand for mobile broadband access, but also to advance and enhance the user experience of mobile communications. Summary of the invention

[0008] The following summarizes some aspects of the present disclosure to provide a basic understanding of the technology discussed. This summary is not an exhaustive review of all expected features of the present disclosure, and is neither intended to identify key or important elements of all aspects of the present disclosure, nor is it intended to describe the scope of any or all aspects of the present disclosure. Its sole purpose is to provide some concepts of one or more aspects of the present disclosure in the form of an overview as a prelude to a more detailed description given later.

[0009] The described technology relates to improved methods, systems, devices and apparatuses that support enhanced congestion control processes for device-to-device communications, such as vehicle-to-everything (V2X) communications. Such congestion control can enable enhanced operation in next-generation wireless modes, such as improved aperiodic communication performance in fifth-generation wireless new radios. Therefore, such technology can improve reliability and throughput, reduce latency, and enable operation in URLLC mode.

[0010] In one aspect of the present disclosure, a method of wireless communication includes: determining, by a user equipment (UE), a channel busy rate (CBR) window for channel busy rate (CBR) measurement for one or more resources; determining, by the UE, CBR measurement values ​​for the CBR window and for one or more resources; determining, by the UE, a channel occupancy rate (CR) window based on a first number of subframes used historically for past transmissions and based on a second number of subframes used for future planned transmissions and corresponding retransmissions; and determining, by the UE, a CR value for the CR window based on subchannels used for one or more resources for the first number of subframes and based on subchannels estimated for one or more resources for the second number of subframes.

[0011] In an additional aspect of the present disclosure, a device configured for wireless communication is disclosed. The device includes: a unit for determining, by a user equipment (UE), a channel busy rate (CBR) window for channel busy rate (CBR) measurement for one or more resources; a unit for determining, by the UE, a CBR measurement value for the CBR window and for one or more resources; a unit for determining, by the UE, a channel occupancy rate (CR) window based on a first number of subframes used historically for past transmissions and based on a second number of subframes used for future planned transmissions and corresponding retransmissions; and a unit for determining, by the UE, a CR value for the CR window based on subchannels used for one or more resources for the first number of subframes and based on subchannels estimated for one or more resources for the second number of subframes.

[0012] In an additional aspect of the present disclosure, a non-transitory computer-readable medium has program code recorded thereon. The program code includes code for performing the following operations: determining, by a user equipment (UE), a channel busy rate (CBR) window for channel busy rate (CBR) measurement for one or more resources; determining, by the UE, a CBR measurement value for the CBR window and for one or more resources; determining, by the UE, a channel occupancy rate (CR) window based on a first number of subframes used historically for past transmissions and based on a second number of subframes used for future planned transmissions and corresponding retransmissions; and determining, by the UE, a CR value for the CR window based on subchannels used for one or more resources for the first number of subframes and based on subchannels estimated for one or more resources for the second number of subframes.

[0013] In an additional aspect of the present disclosure, a device configured for wireless communication is disclosed. The device includes: at least one processor; and a memory coupled to the processor. The processor is configured to: determine, by a user equipment (UE), a channel busy rate (CBR) window for channel busy rate (CBR) measurement for one or more resources; determine, by the UE, a CBR measurement value for the CBR window and for one or more resources; determine, by the UE, a channel occupancy rate (CR) window based on a first number of subframes used historically for past transmissions and based on a second number of subframes used for future planned transmissions and corresponding retransmissions; and determine, by the UE, a CR value for the CR window based on subchannels used for one or more resources for the first number of subframes and based on subchannels estimated for one or more resources for the second number of subframes.

[0014] The foregoing has been fairly extensively outlined according to the features and technical advantages of the examples of the present disclosure, so that the specific embodiments below can be better understood. Additional features and advantages will be described below. The disclosed concepts and specific examples can be easily utilized as the basis for modifying or designing other structures for the same purpose of achieving the present disclosure. Such equivalent constructions do not depart from the scope of the appended claims. According to the description below, when considered in conjunction with the accompanying drawings, the characteristics of the concepts disclosed herein (both their organization and method of operation) and the associated advantages will be better understood. Each of the figures in the accompanying drawings is provided for the purpose of illustration and description, and not as a definition of the limitations of the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] A further understanding of the nature and advantages of the present disclosure may be achieved by reference to the accompanying drawings below. In the accompanying drawings, similar components or features may have the same reference numerals. In addition, various components of the same type may be distinguished by following the reference numeral with a dash and a second mark that distinguishes between similar components. If only the first reference numeral is used in the specification, the description may apply to any of the similar components having the same first reference numeral without regard to the second reference numeral.

[0016] Figure 1 is a block diagram showing details of a wireless communication system.

[0017] Figure 2 is a block diagram showing a design of a base station and a UE configured according to one aspect of the present disclosure.

[0018] Figure 3 is a diagram of a device-to-device communication system.

[0019] Figure 4is an example diagram illustrating device-to-device communication.

[0020] Figure 5 is a block diagram illustrating an example of a wireless communication system implementing enhanced congestion control for device-to-device communications in accordance with aspects of the present disclosure.

[0021] Figure 6 is a block diagram illustrating example blocks executed by a UE configured according to one aspect of the present disclosure.

[0022] Figure 7 is a block diagram illustrating example blocks executed by a UE configured according to another aspect of the present disclosure.

[0023] Figure 8 is a block diagram conceptually illustrating a design of a UE according to some embodiments of the present disclosure. DETAILED DESCRIPTION

[0024] The following summarizes some aspects of the present disclosure to provide a basic understanding of the technology discussed. This summary is not an exhaustive review of all expected features of the present disclosure, and is neither intended to identify key or important elements of all aspects of the present disclosure, nor is it intended to describe the scope of any or all aspects of the present disclosure. Its sole purpose is to provide some concepts of one or more aspects of the present disclosure in the form of an overview as a prelude to a more detailed description given later.

[0025] The detailed description relates to congestion control enhancements for device-to-device (D2D) communications. Traditionally, congestion control for D2D communications is based on both usage history and estimated usage for future transmissions. However, estimating future usage may not be reliable in all scenarios. For example, when non-periodic communications are being used, a device may not accurately estimate its future usage or usage of other devices and / or media. Accordingly, the UE may not accurately determine congestion information and / or may not be able to effectively perform congestion control. For some operating modes (such as URLLC (e.g., eURLLC)), such a process may not be able to achieve high reliability and / or achieve low latency requirements or constraints.

[0026] The described technology relates to improved methods, systems, devices and apparatuses that support congestion control enhancement for D2D communications (including for aperiodic communications). For example, channel busy rate and channel occupancy calculations can be based on more restricted estimates of possible future transmissions. For example, in some implementations, the future window for congestion control estimation can be limited to currently scheduled aperiodic transmissions. Such enhanced congestion control enhancements can enable enhanced operation in D2D communication modes (such as for V2X NR). Accordingly, such techniques can improve reliability and throughput, reduce latency, and enable operation in URLLC mode.

[0027] The detailed description set forth below in conjunction with the accompanying drawings is intended as a description of various configurations and is not intended to limit the scope of the present disclosure. Specifically, the detailed description includes specific details for the purpose of providing a thorough understanding of the subject matter of the invention. It will be apparent to those skilled in the art that these specific details are not required in every case, and in some instances, for the sake of clarity of presentation, well-known structures and components are shown in block diagram form.

[0028] In summary, the present disclosure relates to providing or participating in authorized shared access between two or more wireless communication systems (also referred to as wireless communication networks). In various embodiments, the techniques and devices can be used for wireless communication networks such as the following and other communication networks: code division multiple access (CDMA) networks, time division multiple access (TDMA) networks, frequency division multiple access (FDMA) networks, orthogonal FDMA (OFDMA) networks, single carrier FDMA (SC-FDMA) networks, LTE networks, GSM networks, 5th generation (5G) or new radio (NR) networks. As described herein, the terms "network" and "system" can be used interchangeably.

[0029] OFDMA network can realize radio technology such as Evolved UTRA (E-UTRA), IEEE 802.11, IEEE 802.16, IEEE802.20, Flash-OFDM, etc. UTRA, E-UTRA and Global System for Mobile Communications (GSM) are part of Universal Mobile Telecommunication System (UMTS). Specifically, Long Term Evolution (LTE) is a version of UMTS using E-UTRA. UTRA, E-UTRA, GSM, UMTS and LTE are described in documents provided by an organization named "3rd Generation Partnership Project" (3GPP), and cdma2000 is described in documents from an organization named "3rd Generation Partnership Project 2" (3GPP2). These various radio technologies and standards are known or are being developed. For example, the 3rd Generation Partnership Project (3GPP) is a collaboration between telecommunication association groups with the goal of defining a globally applicable third generation (3G) mobile phone specification. 3GPP Long Term Evolution (LTE) is a 3GPP plan with the goal of improving the Universal Mobile Telecommunication System (UMTS) mobile phone standard. 3GPP may define specifications for next generation mobile networks, mobile systems, and mobile devices. The present disclosure relates to the evolution of wireless technologies from LTE, 4G, 5G, NR and beyond with shared access to wireless spectrum between networks using a new and different set of radio access technologies or wireless air interfaces.

[0030] Specifically, 5G networks are expected to enable diverse deployments, diverse spectrum, and diverse services and devices using a unified air interface based on OFDM. To achieve these goals, in addition to developing new radio technologies for 5G NR networks, further enhancements to LTE and LTE-A are also considered. 5G NR will be able to expand to: (1) ultra-high density (e.g., ~1M nodes / km) 2 ), ultra-low complexity (e.g., ~10s of bits / second), ultra-low energy (e.g., ~10+ years of battery life) coverage for the massive Internet of Things (IoT), and deep coverage with the ability to reach challenging locations; (2) mission-critical control including strong security for protecting sensitive personal, financial, or confidential information, ultra-high reliability (e.g., ~99.9999% reliability), ultra-low latency (e.g., ~1ms), and users with a wide range of mobility or lack of mobility; and (3) enhanced mobile broadband including extremely high capacity (e.g., ~10Tbps / km 2 ), extreme data rates (e.g., multi-Gbps rates, 100+Mbps user experience rates), and deep perception with advanced discovery and optimization.

[0031] 5G NR can be implemented using an optimized OFDM-based waveform with scalable numerology and transmission time interval (TTI); with a common flexible framework to efficiently multiplex services and features using dynamic, low-latency time division duplex (TDD) / frequency division duplex (FDD) design; and with advanced wireless technologies such as massive multiple-input multiple-output (MIMO), robust millimeter wave (mmWave) transmission, advanced channel decoding, and device-centric mobility. The scalability of the digital scheme in 5G NR (with scaling of subcarrier spacing) can efficiently address the operation of diverse services across diverse spectrums and diverse deployments. For example, in various outdoor and macro coverage deployments of less than 3GHz FDD / TDD implementations, the subcarrier spacing can appear at 15kHz on bandwidths such as 1, 5, 10, 20MHz, etc. For other various outdoor and small cell coverage deployments of TDD greater than 3GHz, the subcarrier spacing can appear at 30kHz on 80 / 100MHz bandwidth. For various other indoor broadband implementations, using TDD on the unlicensed portion of the 5 GHz band, the subcarrier spacing may occur at 60 kHz over a 160 MHz bandwidth. Finally, for various deployments transmitting with the millimeter wave component at TDD at 28 GHz, the subcarrier spacing may occur at 120 kHz over a 500 MHz bandwidth.

[0032] 5G NR's scalable digital scheme facilitates scalable TTI for different latency and quality of service (QoS) requirements. For example, shorter TTIs can be used for low latency and high reliability, while longer TTIs can be used for higher spectral efficiency. Efficient multiplexing of long TTIs and short TTIs allows transmissions to start on symbol boundaries. 5G NR also anticipates a self-contained integrated subframe design in which uplink / downlink scheduling information, data, and acknowledgments are in the same subframe. The self-contained integrated subframe supports communications in unlicensed or contention-based shared spectrum, adaptive uplink / downlink (which can be flexibly configured on a per-cell basis to dynamically switch between uplink and downlink to meet current business needs).

[0033] The following further describes various other aspects and features of the present disclosure. It should be apparent that the teachings herein can be embodied in a variety of forms, and any specific structure, function, or both disclosed herein are only representative and not restrictive. Based on the teachings herein, it should be appreciated by those of ordinary skill in the art that the aspects disclosed herein can be implemented independently of any other aspects, and two or more of these aspects can be combined in various ways. For example, using any number of aspects set forth herein, a device can be implemented or a method can be put into practice. In addition, using other structures, functions, or structures and functions other than or different from one or more of the aspects set forth herein, such a device can be implemented or such a method can be put into practice. For example, a method can be implemented as a part of a system, device, device, and / or as an instruction stored on a computer-readable medium for execution on a processor or computer. In addition, an aspect can include at least one element of a claim.

[0034] Figure 1 1 is a block diagram illustrating a 5G network 100 including various base stations and UEs configured according to various aspects of the present disclosure. The 5G network 100 includes several base stations 105 and other network entities. A base station may be a station that communicates with a UE, and may also be referred to as an evolved node (eNB), a next generation eNB (gNB), an access point, etc. Each base station 105 may provide communication coverage for a specific geographic area. In 3GPP, the term "cell" may refer to that specific geographic coverage area of ​​a base station and / or a base station subsystem serving that coverage area, depending on the context in which the term is used.

[0035] A base station may provide communication coverage for macro cells or small cells (such as pico cells or femto cells) and / or other types of cells. A macro cell typically covers a relatively large geographic area (e.g., a radius of several kilometers) and may allow unrestricted access by UEs with service subscriptions with a network provider. A small cell (such as a pico cell) will typically cover a relatively small geographic area and may allow unrestricted access by UEs with service subscriptions with a network provider. A small cell (such as a femto cell) will typically also cover a relatively small geographic area (e.g., a residence) and, in addition to unrestricted access, may also provide restricted access by UEs associated with the femto cell (e.g., UEs in a closed subscriber group (CSG), UEs for users in a residence, etc.). A base station for a macro cell may be referred to as a macro base station. A base station for a small cell may be referred to as a small cell base station, a pico base station, a femto base station, or a home base station. In Figure 1In the example shown in FIG. 1 , base stations 105d and 105e are conventional macro base stations, while base stations 105a-105c are macro base stations implemented using one of 3-dimensional (3D), full-dimensional (FD), or massive MIMO. Base stations 105a-105c use their higher-dimensional MIMO capabilities to use 3D beamforming in both elevation and azimuth beamforming to increase coverage and capacity. Base station 105f is a small cell base station, which can be a home node or a portable access point. The base station can support one or more (e.g., two, three, four, etc.) cells.

[0036] The 5G network 100 may support synchronous operation or asynchronous operation. For synchronous operation, the base stations may have similar frame timing, and transmissions from different base stations may be approximately aligned in time. For asynchronous operation, the base stations may have different frame timing, and transmissions from different base stations may not be aligned in time.

[0037] UE 115 is scattered throughout the wireless network 100, and each UE can be stationary or mobile. UE can also be referred to as a terminal, a mobile station, a user unit, a station, etc. UE can be a cellular phone, a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a tablet computer, a laptop computer, a cordless phone, a wireless local loop (WLL) station, etc. In one aspect, the UE can be a device including a universal integrated circuit card (UICC). In another aspect, the UE can be a device that does not include a UICC. In some aspects, a UE that does not include a UICC can also be referred to as an Internet of Everything (IoE) or Internet of Things (IoT) device. UE 115a-115d is an example of a mobile smart phone type device accessing the 5G network 100. UE can also be a machine that is specifically configured for connected communications (including machine type communications (MTC), enhanced MTC (eMTC), narrowband IoT (NB-IoT), etc.). UE 115e-115k is an example of various machines configured for communication that access the 5G network 100. The UE can communicate with any type of base station (whether macro base station, small cell, etc.). Figure 1 In the present invention, lightning (e.g., communication link) indicates wireless transmission between a UE and a serving base station (which is a base station designated to serve the UE on a downlink and / or uplink), or expected transmission between base stations, and backhaul transmission between base stations.

[0038] In operation at the 5G network 100, base stations 105a-105c use 3D beamforming and coordinated spatial techniques (such as coordinated multipoint (CoMP) or multi-connectivity) to serve UEs 115a and 115b. Macro base station 105d performs backhaul communications with base stations 105a-105c and small cell base station 105f. Macro base station 105d also transmits multicast services that are subscribed to and received by UEs 115c and 115d. Such multicast services may include mobile TV or streaming video, or may include other services for providing community information, such as weather emergencies or alerts (such as Amber Alerts or Gray Alerts).

[0039] The 5G network 100 also supports mission-critical communications with ultra-reliable and redundant links for mission-critical devices, such as UE 115e, which is a drone. Redundant communication links with UE 115e include from macro base stations 105d and 105e and small cell base station 105f. Other machine-type devices, such as UE 115f (thermometer), UE 115g (smart meter), and UE 115h (wearable device), can communicate directly with base stations, such as small cell base station 105f and macro base station 105e, through the 5G network 100, or in a multi-hop configuration by communicating with another user device that relays its information to the network, such as UE 115f transmitting temperature measurement information to the smart meter (UE 115g), which is then reported to the network through the small cell base station 105f. The 5G network 100 may also provide additional network efficiency through dynamic low latency TDD / FDD communications, such as in a vehicle-to-vehicle (V2V) mesh network between UEs 115i-115k communicating with a macro base station 105e.

[0040] Figure 2 Base station 105 and UE 115 (which may be Figure 1A block diagram of a design of a base station in a base station and a UE in a UE). At the base station 105, the transmit processor 220 can receive data from the data source 212 and control information from the controller / processor 240. The control information can be used for PBCH, PCFICH, PHICH, PDCCH, EPDCCH, MPDCCH, etc. The data can be used for PDSCH, etc. The transmit processor 220 can process (e.g., encode and symbol map) the data and control information respectively to obtain data symbols and control symbols. The transmit processor 220 can also generate reference symbols for example for PSS, SSS, and cell-specific reference signals. The transmit (TX) multiple-input multiple-output (MIMO) processor 230 can perform spatial processing (e.g., precoding) on ​​data symbols, control symbols, and / or reference symbols (if applicable), and can provide output symbol streams to modulators (MOD) 232a to 232t. Each modulator 232 can process a corresponding output symbol stream (e.g., for OFDM, etc.) to obtain an output sample stream. Each modulator 232 may further process (eg, convert to analog, amplify, filter, and upconvert) the output sample stream to obtain a downlink signal. The downlink signals from modulators 232a through 232t may be transmitted via antennas 234a through 234t, respectively.

[0041] At the UE 115, antennas 252a to 252r can receive downlink signals from the base station 105 and can provide received signals to demodulators (DEMOD) 254a to 254r, respectively. Each demodulator 254 can adjust (e.g., filter, amplify, downconvert, and digitize) the corresponding received signal to obtain input samples. Each demodulator 254 can further process the input samples (e.g., for OFDM, etc.) to obtain received symbols. The MIMO detector 256 can obtain received symbols from all demodulators 254a to 254r, perform MIMO detection on the received symbols (if applicable), and provide detected symbols. The receive processor 258 can process (e.g., demodulate, deinterleave, and decode) the detected symbols, provide decoded data for the UE 115 to the data sink 260, and provide decoded control information to the controller / processor 280.

[0042] On the uplink, at the UE 115, a transmit processor 264 may receive and process data from a data source 262 (e.g., for PUSCH) and control information from a controller / processor 280 (e.g., for PUCCH). The transmit processor 264 may also generate reference symbols for reference signals. The symbols from the transmit processor 264 may be precoded by a TX MIMO processor 266 (if applicable), further processed by modulators 254a through 254r (e.g., for SC-FDM, etc.), and sent to the base station 105. At the base station 105, the uplink signal from the UE 115 may be received by the antenna 234, processed by the demodulator 232, detected by the MIMO detector 236 (if applicable), and further processed by the receive processor 238 to obtain decoded data and control information sent by the UE 115. The processor 238 may provide the decoded data to the data sink 239 and the decoded control information to the controller / processor 240.

[0043] The controllers / processors 240 and 280 may direct the operation at the base station 105 and the UE 115, respectively. The controller / processor 240 and / or other processors and modules at the base station 105 may perform or direct the execution of various processes for the techniques described herein. The controller / processor 280 and / or other processors and modules at the UE 115 may also perform or direct the execution of various processes for the techniques described herein. Figure 6 and Figure 7 The functional blocks shown in the figure and / or the execution of other processes for the techniques described herein. Memories 242 and 282 can store data and program codes for base station 105 and UE 115, respectively. Scheduler 244 can schedule UEs for data transmission on the downlink and / or uplink.

[0044] Wireless communication systems operated by different network operating entities (e.g., network operators) may share spectrum. In some instances, a network operating entity may be configured to use the entire designated shared spectrum for at least one time period before another network operating entity uses the entire designated shared spectrum for a different time period. Therefore, in order to allow network operating entities to use the entire designated shared spectrum, and to mitigate interfering communications between different network operating entities, certain resources (e.g., time) may be divided and allocated to different network operating entities for certain types of communications.

[0045] For example, a network operating entity may be allocated certain time resources that are reserved for exclusive communication by the network operating entity using the entire shared spectrum. The network operating entity may also be allocated other time resources in which it is given priority over other network operating entities to communicate using the shared spectrum. The time resources prioritized for use by the network operating entity may be used on an opportunistic basis by other network operating entities if the prioritized network operating entity does not use those resources. Additional time resources may be allocated for use by any network operator on an opportunistic basis.

[0046] Access to the shared spectrum and arbitration of time resources between different network operating entities may be centrally controlled by a separate entity, autonomously determined by a predefined arbitration scheme, or dynamically determined based on interactions between the network operator's wireless nodes.

[0047] In some cases, 5G network 100 (in Figure 1 A UE 115 and a base station 105 (in a shared radio frequency spectrum band) may operate in a shared radio frequency spectrum band (which may include licensed or unlicensed (e.g., contention-based) spectrum). In the unlicensed frequency portion of the shared radio frequency spectrum band, the UE 115 or the base station 105 may conventionally perform a medium sensing process to compete for access to the spectrum. For example, the UE 115 or the base station 105 may perform a listen-before-talk (LBT) process (such as a clear channel assessment (CCA)) before communicating to determine whether the shared channel is available. CCA may include an energy detection process to determine whether there are any other active transmissions. For example, the device may infer that a change in a received signal strength indicator (RSSI) of a power meter indicates that the channel is occupied. Specifically, a signal power concentrated in a certain bandwidth and exceeding a predetermined background noise may indicate another wireless transmitter. CCA may also include detection of a specific sequence indicating use of the channel. For example, another device may send a specific preamble before sending a data sequence. In some cases, the LBT process may include the wireless node adjusting its own backoff window based on the amount of energy detected on the channel and / or acknowledgement / negative acknowledgement (ACK / NACK) feedback for packets it itself sent as a proxy for collisions.

[0048] Generally, four categories of LBT procedures have been proposed to sense a shared channel for signals that may indicate that the channel is already occupied. In the first category (CAT 1 LBT), no LBT or CCA is applied to detect occupancy of a shared channel. The second category (CAT 2 LBT) (which may also be referred to as shortened LBT, single LBT, or 25-μs LBT) provides for nodes to perform CCA to detect energy above a predetermined threshold or to detect a message or preamble occupying a shared channel. CAT 2 LBT performs CCA without using a random backoff operation, which results in its shortened length relative to the next category.

[0049] The third category (CAT 3LBT) performs CCA to detect energy or messages on a shared channel, but also uses random backoff and a fixed contention window. Therefore, when a node initiates CAT 3LBT, it performs a first CCA to detect occupancy of the shared channel. If the shared channel is idle for the duration of the first CCA, the node can continue to send. However, if the first CCA detects a signal occupying the shared channel, the node selects a random backoff based on the fixed contention window size and performs an extended CCA. If the shared channel is detected to be idle during the extended CCA and the random number has been decremented to 0, the node can start transmission on the shared channel. Otherwise, the node decrements the random number and performs another extended CCA. The node will continue to perform extended CCAs until the random number reaches 0. If the random number reaches 0 without detecting channel occupancy at any extended CCA, the node can then send on the shared channel. If at any extended CCA, the node detects channel occupancy, the node can reselect a new random backoff based on the fixed contention window size to start the countdown again.

[0050] The fourth category (CAT 4 LBT) (which may also be referred to as a full LBT process) performs CCA using energy or message detection using random backoff and a variable contention window size. The sequence of CCA detection is performed similarly to the process of CAT 3 LBT, except that the contention window size is variable for the CAT 4 LBT process.

[0051] Using a medium sensing process to compete for access to an unlicensed shared spectrum may result in communication inefficiencies. This may be particularly evident when multiple network operating entities (e.g., network operators) are trying to access shared resources. In a 5G network 100, base stations 105 and UEs 115 may be operated by the same or different network operating entities. In some examples, a single base station 105 or UE 115 may be operated by more than one network operating entity. In other examples, each base station 105 and UE 115 may be operated by a single network operating entity. Requiring each base station 105 and UE 115 of different network operating entities to compete for shared resources may result in increased signaling overhead and communication latency.

[0052] Figure 3 360. The D2D communication system 360 includes a plurality of UEs 364, 366, 368, 370. The D2D communication system 360 may overlap with a cellular communication system (such as, for example, a WWAN). Some of the UEs 364, 366, 368, 370 may communicate together in D2D communication using DL / UL WWAN spectrum, some of the UEs may communicate with a base station 362, and some of the UEs may perform both operations. For example, Figure 3 As shown in FIG, UE 368, 370 are in D2D communication, and UE 364, 366 are in D2D communication. UE 364, 366 also communicates with base station 362. D2D communication can be through one or more sidelink channels, such as physical sidelink broadcast channel (PSBCH), physical sidelink discovery channel (PSDCH), physical sidelink shared channel (PSSCH) and physical sidelink control channel (PSCCH).

[0053] The exemplary methods and apparatus discussed below are applicable to any of a variety of wireless D2D communication systems, such as, for example, wireless device-to-device communication systems based on: NR, LTE, FlashLinQ, WiMedia, Bluetooth, ZigBee, or Wi-Fi based on the IEEE 802.11 standard. To simplify the discussion, the exemplary methods and apparatus are discussed in the context of NR. However, one of ordinary skill in the art will appreciate that the exemplary methods and apparatus are more generally applicable to a variety of other wireless device-to-device communication systems.

[0054] D2D communication can be used to provide direct communication between devices. D2D communication enables one device to communicate with another device and send data to the other device on allocated resources. One use for D2D communication is vehicle-to-vehicle (V2V) communication and vehicle-to-everything (V2X) communication. Therefore, according to V2V communication, a device of a first vehicle can perform D2D communication with a device of another vehicle. According to V2X communication, a device of a vehicle can perform D2D communication with another device, regardless of whether the device resides in the vehicle.

[0055] One type of communication that can be used for V2V communication is dedicated short range communication (DSRC). DSRC is a short-range wireless communication capability that is typically based on IEEE 802.11p, similar to Wi-FI. In DSRC, devices can check the channel before transmitting. For traffic-related communications (e.g., V2X communications), the 5.9 GHz unlicensed spectrum is typically reserved to transmit intelligent transportation services (ITS). Recently, implementations of other types of communications, such as NR communications for V2V communications, have been under development. For example, NRD2D can be used for V2V communications on licensed spectrum and / or unlicensed spectrum.

[0056] In a vehicle-to-everything (V2X) wireless communication system, a UE may communicate directly using device-to-device communication (also referred to as sidelink communication) without using a network entity (e.g., a base station) as an intermediary. In some cases, a UE may operate using a specific transmission mode (such as transmission mode 4), in which resource selection and / or scheduling is performed by the UE rather than a network entity (e.g., a base station). In some aspects, the UE may perform resource selection and / or scheduling by measuring one or more sidelink channels, by decoding sidelink control information (SCI) indicating channel availability, by determining a channel busy rate (CBR) associated with various sidelink channels, and the like.

[0057] In transmission mode 4, the UE may generate a sidelink grant and may send the sidelink grant in the SCI. The sidelink grant may indicate, for example, one or more parameters (e.g., transmission parameters) to be used for an upcoming V2X transmission (e.g., V2X data transmission), such as one or more resource blocks to be used for the upcoming V2X transmission, one or more subframes to be used for the upcoming V2X transmission, a modulation and coding scheme (MCS) to be used for the upcoming V2X transmission, etc.

[0058] In a V2X communication system, the conditions of the sidelink channel used to carry V2X communication may vary greatly and change rapidly due to the high mobility of vehicles and UEs associated with the vehicles, the large variation of vehicle traffic at different times of the day and in different locations, the various terrains that vehicles may traverse (e.g., dense urban environments, hilly environments, flat environments, etc.), etc. In addition, due to mission-critical safety issues associated with, for example, autonomous vehicles, V2X communication systems need to be highly reliable. Some techniques and devices described herein improve the performance of V2X communication systems by dynamically determining parameters for V2X transmissions based at least in part on dynamic factors associated with one or more vehicles, sidelink channels, etc.

[0059] In some aspects, the V2X transmission may be a one-to-many broadcast and / or multicast transmission. In some aspects, the V2X transmission may not require any physical layer feedback from the receiving device, such as an acknowledgement (ACK) or negative acknowledgement (NACK) feedback. In some aspects, the V2X transmission may be configured to have no retransmissions. In some aspects, the V2X transmission may be configured to have a number of retransmissions (e.g., five retransmissions). In certain aspects, the retransmission occurs automatically, such as in the absence of ACK / NACK feedback.

[0060] The first UE may communicate with the second UE (and one or more other UEs) using device-to-device (D2D) communication via one or more sidelink channels. In some aspects, the UE may correspond to one or more other UEs described elsewhere herein. The UE may use the sidelink channel to send V2X communications.

[0061] The sidelink channel may include a PSCCH and a PSSCH. The sidelink channel may optionally include a physical sidelink feedback channel (PSFCH). The PSCCH may be used to transmit control information, similar to a physical downlink control channel (PDCCH) and / or a physical uplink control channel (PUCCH) for communication with a base station. The PSSCH may be used to transmit data, similar to a physical downlink shared channel (PDSCH) and / or a physical uplink shared channel (PUSCH) for communication with a base station. For example, the PSCCH may carry sidelink control information (SCI), which may indicate various control information for sidelink communication, such as one or more resources (e.g., time resources and / or frequency resources), wherein a transport block (TB) including data is carried on the PSSCH. The TB may include V2X data, such as a basic safety message (BSM), a traffic information message (TIM), a signal phase and time (SPAT) message, a MAP message for transmitting geographic road information, a collaborative awareness message (CAM), a distributed environment notification message (DENM), an in-vehicle information (IVI) message, and the like.

[0062] In some aspects, a sidelink channel may use a resource pool. For example, a scheduling assignment (e.g., included in an SCI) may be sent in a subchannel using specific resource blocks (RBs) across time. In some aspects, a data transmission associated with a scheduling assignment (e.g., on a PSSCH) may occupy adjacent RBs in the same subframe as the scheduling assignment (e.g., using frequency division multiplexing). In some aspects, the scheduling assignment and the associated data transmission are not sent on adjacent RBs.

[0063] In some aspects, the UE may operate using transmission mode 4, in which resource selection and / or scheduling is performed by the UE (e.g., rather than the base station). In some aspects, the UE may perform resource selection and / or scheduling by sensing channel availability for transmission. For example, the UE may measure received signal strength indicator (RSSI) parameters associated with various sidelink channels (e.g., sidelink RSSI (S-RSSI) parameters), may measure reference signal received power (RSRP) parameters associated with various sidelink channels (e.g., PSSCH-RSRP parameters), may measure reference signal received quality (RSRQ) parameters associated with various sidelink channels (e.g., PSSCH-RSRQ parameters), etc., and may select a channel for transmission for V2X communication based at least in part on the measurements.

[0064] Additionally or alternatively, the UE may perform resource selection and / or scheduling using the SCI received in the PSCCH, which may indicate occupied resources, channel parameters, etc. Additionally or alternatively, the UE may perform resource selection and / or scheduling by determining a channel busy rate (CBR) associated with various sidelink channels, which may be used for rate control (e.g., by indicating a maximum number of resource blocks that the UE may use for a particular set of subframes).

[0065] In transmission mode 4, the UE may generate a sidelink grant and may send the grant in the SCI. The sidelink grant may indicate, for example, one or more parameters (e.g., transmission parameters) to be used for an upcoming V2X transmission, such as one or more resource blocks to be used for the upcoming V2X transmission on the PSSCH (e.g., for a TB), one or more subframes to be used for the upcoming V2X transmission, a modulation and coding scheme (MCS) to be used for the upcoming V2X transmission, etc. In some aspects, the UE may generate a sidelink grant indicating one or more parameters for semi-persistent scheduling (SPS), such as the periodicity of the V2X transmission (e.g., periodic V2X messages, such as safety messages, etc.). Additionally or alternatively, the UE may generate a sidelink grant for event-driven scheduling, such as for on-demand V2X messages.

[0066] In a V2X communication system, the conditions of the sidelink channel used to carry V2X communication may vary greatly and change rapidly due to the high mobility of vehicles and UEs associated with the vehicles, the large variation of vehicle traffic at different times of the day and in different locations, the various terrains that vehicles may traverse (e.g., dense urban environments, hilly environments, flat environments, etc.), etc. In addition, due to mission-critical safety issues associated with, for example, autonomous vehicles, V2X communication systems need to be highly reliable. Some techniques and devices described herein improve the performance of V2X communication systems by dynamically determining parameters for V2X transmissions based at least in part on dynamic factors associated with one or more vehicles, sidelink channels, etc.

[0067] In some implementations, in accordance with various aspects of the present disclosure, a UE may be able to perform autonomous resource selection for V2X transmissions.

[0068] For example, the UE may determine a limit on the number of resource blocks (RBs) allowed for V2X transmissions performed by the UE. In some aspects, the UE may determine the limit based at least in part on a congestion level of one or more sidelink channels, which may be determined based at least in part on measuring the one or more sidelink channels (e.g., for S-RSSI, PSSCH-RSRP, etc.), receiving SCI associated with the one or more sidelink channels, etc. For example, the UE may determine a channel busy rate (CBR) for the sidelink channel in association with a time n at which resource selection is triggered for the UE (e.g., CBR(n-100, n-1), where n-100 represents the beginning of the time period and n-1 represents the end of the time period), and may determine a maximum number of RBs allowed for use by the UE at time n based at least in part on the CBR. Additionally or alternatively, the UE may determine a limit on the number of RBs by determining a maximum number of RBs allowed for use by the UE in association with time n (e.g., CRlimit(n)) and subtracting a number of RBs already used or scheduled by the UE in association with time n (e.g., CR(na,n+b), where na represents the beginning of the time period and n+b represents the end of the time period).

[0069] The UE may determine one or more parameters for V2X transmission based at least in part on the limit on the number of RBs. In some aspects, the one or more parameters may be referred to as one or more transmission parameters and / or one or more V2X transmission parameters. As shown, the one or more parameters may include a modulation and coding scheme (MCS) for V2X transmission, a number of transport blocks (TBs) for V2X transmission, a number of RBs per TB for V2X transmission, a retransmission configuration for V2X transmission, etc. In some aspects, the UE may determine one or more parameters so that the number of RBs for V2X transmission does not exceed the limit on the number of RBs.

[0070] As an example, if the UE selects an MCS with a lower index value (e.g., allowing fewer bits per symbol) for a V2X transmission, the V2X transmission will require more TBs and corresponding RBs than if the same V2X transmission used an MCS with a higher index value (e.g., allowing more bits per symbol). However, using an MCS with a lower index value for V2X transmissions may increase the range of the V2X transmission and / or may improve the reliability of the V2X transmissions compared to using an MCS with a higher index value. Thus, in some aspects, if the limit on the number of RBs is relatively high (e.g., greater than or equal to a threshold), the UE may select an MCS with a lower index value, and if the limit on the number of RBs is relatively low (e.g., less than or equal to a threshold), the UE may select an MCS with a higher index value. In some aspects, the UE may select from a plurality of different MCS index values, and different MCS index values ​​may be associated with different thresholds for the limit on the number of RBs.

[0071] As another example, if the UE configures the retransmission configuration to enable retransmission for a V2X transmission, the V2X transmission will require more TBs and corresponding RBs than if the UE configures the retransmission configuration to disable retransmission for the same V2X transmission. However, enabling retransmission for the V2X transmission may increase the range of the V2X transmission and / or may improve the reliability of the V2X transmission compared to disabling retransmission for the V2X transmission. Thus, in some aspects, if the limit on the number of RBs is relatively high (e.g., greater than or equal to a threshold), the UE may enable retransmission, and if the limit on the number of RBs is relatively low (e.g., less than or equal to a threshold), the UE may disable retransmission. In some aspects, the UE may select from a plurality of different numbers of retransmissions (e.g., one retransmission, two retransmissions, etc.), and the different numbers of retransmissions may be associated with different thresholds for the limit on the number of RBs.

[0072] In some aspects, the UE may select one or more parameters to increase or maximize the range of a V2X transmission (e.g., the distance that a V2X transmission and corresponding retransmissions can cover) subject to a limit on the number of RBs, as described below in conjunction with Figure 5 In this manner, the UE may improve reliability, may increase security, may increase the likelihood of successfully receiving V2X transmissions, etc., while operating in accordance with a limitation on the number of RBs allowed for V2X transmissions.

[0073] In a V2X communication system, sidelink channel conditions may vary significantly at different times, at different geographic locations, on different frequencies, etc. Therefore, the UE may dynamically determine one or more parameters for V2X transmissions based at least in part on the conditions that exist when scheduling V2X transmissions. In some aspects, the UE may determine one or more transmission parameters based at least in part on dynamic factors associated with the UE and / or vehicles associated with the UE (e.g., network traffic demand, congestion, etc. associated with one or more applications of the UE). Additionally or alternatively, the UE may determine one or more transmission parameters based at least in part on dynamic factors associated with a wireless network via which the V2X transmission is to be sent (e.g., a congestion level associated with the wireless network, a carrier frequency on which the V2X transmission is to be sent, a priority of the V2X transmission on the wireless network, etc.). In this way, the UE may improve or optimize the transmission of V2X messages under changing conditions.

[0074] Additionally or alternatively, the UE may determine one or more V2X transmission parameters based at least in part on the selected one or more frequencies. For example, different frequencies may be associated with different CBR values ​​and, therefore, may be associated with different restrictions on the number of RBs allowed for use by the UE. Additionally or alternatively, different combinations of transmission parameters may result in different performance at different frequencies, and the UE may use this as a factor in determining the one or more transmission parameters.

[0075] In some aspects, the UE may determine one or more transmission parameters based at least in part on a network traffic demand associated with one or more applications of the UE. For example, if the first UE has a relatively high network traffic demand (e.g., the number of requested V2X transmissions is greater than or equal to a threshold), the UE may use a smaller number of RBs per V2X transmission. Conversely, if the UE has a relatively low network traffic demand (e.g., the number of requested V2X transmissions is less than or equal to a threshold), the UE may use a larger number of RBs per V2X transmission. The UE may configure a smaller number of RBs per V2X transmission by using a higher MCS index, by disabling retransmissions or configuring a smaller number of retransmissions, by using a smaller number of TBs, and / or by using a smaller number of RBs per TB. Conversely, the UE may configure a larger number of RBs per V2X transmission by using a lower MCS index, by enabling retransmissions or configuring a larger number of retransmissions, by using a larger number of TBs, and / or by using a larger number of RBs per TB.

[0076] Additionally or alternatively, the UE may determine one or more transmission parameters based at least in part on a congestion level associated with a wireless network via which the V2X transmission is to be sent (e.g., a congestion level of a sidelink channel and / or one or more frequencies via which the V2X transmission is to be sent). For example, if the wireless network has a relatively high congestion level, the UE may use a smaller number of RBs per V2X transmission. Conversely, if the wireless network has a relatively low congestion level, the UE may use a larger number of RBs per V2X transmission. In some aspects, the UE may determine the congestion level based at least in part on the CBR, resource constraints (e.g., rate control parameters, power control parameters, congestion control parameters, etc.), measured parameters of the wireless network (e.g., energy level), etc.

[0077] The UE may send a V2X transmission (e.g., to a second UE and / or one or more other UEs) based at least in part on one or more parameters. For example, the UE may modulate and / or encode the V2X transmission using a selected MCS, may send the V2X transmission using a selected number of TBs, may send the V2X transmission using a selected number of RBs per TB, may retransmit or prevent retransmission of the V2X transmission according to a selected retransmission configuration, may send the V2X transmission on a selected carrier frequency, etc. By considering dynamic factors when determining the above transmission parameters, the UE may improve the performance of the V2X transmission subject to constraints on the V2X transmission (e.g., transmission range). For example, in some cases, the UE may send the V2X transmission using an MCS with a high index instead of discarding the V2X transmission.

[0078] Figure 4 4 is an example diagram illustrating device-to-device communication. A first device 412 (e.g., a UE) is present in a first vehicle 410 and can therefore travel with the first vehicle 410. A second device 432 (e.g., another UE) can be present in a second vehicle 430. In another aspect, the first device 412 can exist independently of the first vehicle 410, or can be a part of the first vehicle 410. The second device 432 can exist independently of the second vehicle 430, or can be a part of the second vehicle 430. The first device 412 and the second device 432 can be connected (e.g., in a connection mode with a base station) to a base station 450. The first device 412 and the second device 432 can also be configured to perform D2D communication with each other via NR. The first device 412 and the second device 432 can also perform short-range communication with each other via IEEE 802.11p.

[0079] Vehicles may include autonomous vehicles, semi-autonomous vehicles, non-autonomous vehicles, etc. Figure 4The two UEs in FIG. 1 are shown as being associated with a vehicle, but in some aspects, one or more of the UEs may not be associated with a vehicle. For example, the UE may be associated with an infrastructure (e.g., a traffic infrastructure) such as a traffic signal, a lane signal, a sensor, a traffic controller system, etc.

[0080] NR V2V communications may provide more reliable performance compared to LTE V2V by providing a more history-based calculation of congestion and / or a more limited reliance on future periodic transmissions. Although the following discussion refers to NR V2V communications by way of illustration and not limitation, NR V2V communications are similar to NR D2D communications, and thus the following discussion may also apply to NR and LTE D2D communications.

[0081] Congestion may occur in NR V2V communications, for example, due to increased network traffic. Congestion control may be implemented to control network congestion via certain parameters related to communication via NR V2V based on the level of congestion. For example, in some cases, there may be no centralized entity to perform congestion control of the spectrum. Congestion control may be performed without a centralized entity (e.g., eNB) to manage admission control and / or radio resource utilization (e.g., operations outside of network coverage, and / or utilizing a decentralized resource selection / reselection process). In the absence of a centralized entity that manages network resources and device communications, conflicts of different communications may occur. Excessive conflicts may adversely affect the performance of the communication system. For example, conflicts may occur when resources are not correctly allocated to different device communications (which may result in some devices not having enough resources for communication). Depending on the communication system and / or the channel access method of the communication system, the device may not be able to handle network congestion. For example, the number of communications that can be reliably and successfully performed in the network may vary depending on the type of communication system. Decentralized congestion control may be based on the 802.11p physical layer and may be generalized to provide coexistence of various technologies. Therefore, in systems that do not have a centralized entity for managing congestion, technology-neutral decentralized congestion control may be desirable.In some aspects, technology-specific enhancements for decentralized congestion control may be provided.

[0082] In one aspect, congestion control can be based on channel busy rate (CBR) and / or channel utilization. CBR can represent the percentage of busy resources. Channel utilization can represent the percentage of channels being used for communication. CBR and channel utilization can be technology-neutral, as described below. Decentralized congestion control for 802.11p technology can be derived based on technology-neutral congestion control, and technology-neutral methods for decentralized congestion control can be used for NR V2V.

[0083] Each UE may estimate channel utilization based on the CBR. The CBR may be an estimate of the percentage of resources that are considered busy / utilized. In one aspect, a resource may be considered busy and / or utilized if a signal is decoded on the resource, or if the energy in such resource is greater than an energy threshold.

[0084] The CBR can be estimated by dividing the number of probes that found the resource busy by the total number of probes on the resource according to the following equation:

[0085]

[0086] in:

[0087] 1Vprobe with resource busy is an indicator function used to detect that a resource is busy.

[0088] Np is the total number of probes that probe a resource for resource busy measurement.

[0089] Nt is the time granularity of resource utilization (e.g., 1 ms TTI for NR, OFDM symbol duration for 802.11p) and Nf is the frequency granularity of resource utilization (e.g., channel BW for 802.11p, 180 kHz for NR). When resources are allocated in time and frequency, Nt and Nf can define the granularity of resources.

[0090] For example, if a UE probes every 10 microseconds, probing for 100 milliseconds will result in a total number of probes equal to 10000. If there are a total of 10000 probes to probe for a busy resource, and 8000 probes find the probed resource to be busy, then the CBR of the system may be 80%.

[0091] CBR can be the number of stations N within a certain proximity Sta (e.g., number of UEs, number of transmitters):

[0092] CBR=f(N sta ),

[0093] Among them, the function f(N sta ) may be technology dependent and may depend on the channel access procedure of the corresponding technology.

[0094] In one aspect, if the estimated CBR exceeds the CBR limit (CBR limit ), congestion control can be performed by limiting the channel utilization per UE. The channel utilization per UE can be expressed as channel resources (CR). The CR limit (e.g., per UE or STA) can be calculated by dividing the total resources available to the system (e.g., CBR) bylim ) divided by the number of stations (eg, UEs) N Sta To determine, it can be expressed as:

[0095]

[0096] In the alternative formula, since when the estimated CBR exceeds the CBR limit (CBR limit ), so the CR limit (e.g., per UE or STA) can be determined as:

[0097]

[0098] In one approach, N Sta The linear function of N is used to estimate CBR, which can be expressed as CBR = a*N sta +b. For technology coexistence with 802.11p, the parameters may be 1 / a=4000 and b=0.62 (target CBR limit). In addition, due to TDMA access (when the device transmits on the entire channel bandwidth and there is no FDMA operation), the CR for 802.11p may be estimated as T on / (T on +T off ), where T on is the duration when the UE is turned on, and T off It is the duration when the UE is turned off. limit can be estimated as T on / (T on +T off_limit ), where T off_limit It is the minimum time that the UE can be switched off to keep the channel utilization less than the CR limit.

[0099] Using the above method for 802.11p, the following equation can be implemented.

[0100]

[0101] Therefore, the CR for 802.11p can be T on Divide by the total time: CR = T on / (T on +T off ). For example, if the UE is on for 400 milliseconds and off for 100 milliseconds, the CR is 400 / (400+100)=4 / 5. In one aspect, if the UE is on longer, the UE should be off longer. In addition, as shown above, T off or T off_limit It can be T onis a linear function of , which depends on the CBR. Therefore, if the channel is busy and therefore the CBR is high, the UE may off or a larger T off_limit And the fallback in transmission is more.

[0102] The above congestion control methods may have the following limitations when used in a system where multiple technologies share network resources. First, the CBR and channel utilization ratio (eg, CR) definitions may only apply to TDMA systems, where CR = T on / (T on +T off ). Secondly, a UE estimating the CBR of the system may treat all radio resources equally, which may cause problems for NR V2V. Specifically, for NR V2V, the total radio resources may be divided into control resources and data resources. When separate resources are used for control and data, the control resources may become congested while the overall resources are not congested (for example, because the data resources are idle and not congested). In such an example, when there are different types of resources, treating all resources equally may not effectively solve the congestion of resources in the system. Therefore, a method of separately considering the CBR for control resources and the CBR for data resources is desired. For example, by separately considering the CBR for control resources and the CBR for data resources, if the control resources are too congested, the system may fail even if the data resources are available. Similarly, by separately considering the CBR for control resources and the CBR for data resources, if the data resources are too congested, the system may fail even if the control resources are available.

[0103] Third, as discussed above, if the signal is decoded on the resource and / or the energy measured on the resource is greater than a threshold, the UE may determine that the resource is busy. However, such determination of a busy resource by the UE may not take into account the coexistence of multiple technologies on the same channel. Therefore, a method of congestion control for the coexistence of multiple technologies when addressing network congestion is desirable. For example, according to one aspect of the present disclosure, in order to achieve coexistence, if the total channel utilization is 80%, each of the technologies may not be allowed to utilize more than 40% of the total resources.

[0104] Fourth, using a single threshold for CBR that is independent of the priority of the transmission may not allow the UE to make the transmission of higher priority packets more important than the transmission of lower priority packets. Therefore, it may be beneficial for the system to have different congestion limits for packets with different priorities. In one aspect, it may be desirable to control packet transmission based on the priority of the packet. For example, according to one aspect of the present disclosure, if the channel utilization exceeds a certain threshold (e.g., 50%), the UE may not send low priority packets, but may send high priority packets, which may provide more resources for sending higher priority packets.

[0105] According to a first aspect of the present disclosure, the CBR may be defined based on the percentage of busy / utilized radio resources within a measurement window. The UE may calculate the CBR based on energy measurements on the resources (CBR e ) and CBR based on decoding the signal on the resource (CBR d ). Specifically, when calculating CBR e If the energy measured on the resource is greater than the threshold (for example, energy S>S threshold ), the UE can determine that the resource is busy. When calculating CBR d If the signal on the resource is decoded, the UE can determine that the resource is busy. If the cyclic redundancy check (CRC) passes, the UE can determine that the signal on the resource is decoded. CBR e and CBR d It can be expressed as follows:

[0106]

[0107]

[0108] According to a second aspect of the present disclosure, for a system with separate control resources and data resources, the UE may separately calculate the CBR for the control resources and the CBR for the data resources. For example, the UE may calculate four types of CBRs, including an energy-based CBR (CBR) for the control resources, an energy-based CBR (CBR) for the data resources, and a CBR for the control resources. control_e ), decoding-based CBR (CBR) for controlling resources control_d ), energy-based CBR (CBR) for data resources data_e ) and decoded CBR (CBR) based on data resources data_d ),as follows:

[0109]

[0110]

[0111]

[0112]

[0113] According to a third aspect of the present disclosure, an upper limit for CBR (e.g., CBR control_e , CBR control_d , CBR data_e , CBR data_d In one aspect, an upper limit for each type of CBR (eg, CBR limit ). In one aspect, the pre-configuration may be performed via at least one of the UE or a universal integrated circuit card (UICC). In one aspect, the dynamic configuration is performed based on at least one of RRC signaling from a base station, signaling from an intelligent transportation system (ITS) server, or signaling from an operator-controlled server. For example, the base station may provide the upper limit to the UE via an RRC message, or the upper limit may be pre-configured within the UE.

[0114] According to a fourth aspect of the present disclosure, a CR upper limit (CR) of a channel utilization rate defined by CR (eg, in terms of a percentage of radio resources) is set. limit ) can be calculated as follows:

[0115]

[0116] Among them, f -1 (CBR) = N sta So that the inverse function f -1 The number of stations (eg, UEs, transmitters) may be determined based on the CBR.

[0117] The inverse function f can be configured -1 , for example, via pre-configuration or dynamic configuration within the UE. In one aspect, the pre-configuration may be performed via at least one of the UE or the UICC. In one aspect, the dynamic configuration is performed based on at least one of RRC signaling from a base station, signaling from an ITS server, or signaling from an operator-controlled server. In one aspect, the function f may be a fixed function (e.g., linear or exponential), or may be dynamically configured in the UE. Based on the CBR limit, the UE may calculate the CR based on a percentage of the radio resources that the UE is allowed to occupy. limit , where CR limit It can indicate the maximum allowed channel utilization.

[0118] CR limitThe CR can be determined based on the energy-based CBR or the decoding-based CBR based on whether the UE detects another technology different from the UE's technology. Specifically, if the UE determines that another technology is detected, the UE can determine the CR based on the decoding-based CBR. limit If the UE determines that another technology is not detected, the UE may determine the CR based on the energy-based CBR. limit . Thus, for example, the CR limit can be determined as follows:

[0119] if (e.g., 0.75)

[0120] but:

[0121] otherwise:

[0122] In the above example, the UE can detect another technology by considering energy instances where the energy (Ec) on the resource is greater than the threshold (Th) and decoding instances where the signal (Ed) can be decoded for the resource with energy (Ec) greater than the threshold (Th). If the ratio of the decoding instance to the energy instance decreases below the technology threshold (Th2), the UE determines that another technology exists and CBR for coexistence between multiple technologies can be used. limit_d To calculate CR limit If the ratio of decoded instances to energy instances does not drop below the technology threshold (Th2), the UE may determine that there is no other technology and therefore use CBR. limit_e To calculate CR limit In one aspect, the UE can ensure that the CBR limit_d Less than or equal to CBR limit_e .f -1 (CBR d ) can be used to calculate CR with UE limit The number of stations (e.g., UEs, transmitters) of the same technology is limited because UEs may not be able to decode signals of different technologies. -1 (CBR e ) can be the number of stations (e.g., UEs, transmitters) utilizing any technology, since the UE considers the energy on the resources, which may include energy caused by the UE's technology as well as energy caused by other technologies.

[0123] If no co-channel coexistence between different technologies is expected, CBR may not be configured. limit_d , and the CR limit can be determined by CBR limit_e Given.

[0124] According to a fifth aspect of the present disclosure, the UE may adjust transmission parameters (e.g., the number of occupied resources, MCS, transmission rate, number of HARQ retransmissions, transmission power, etc.) to keep the CR value within the CR range. limit For example, if CR limit Indicates 10% of the total resources, and the current CR is greater than 10%, the UE can increase the MCS to increase the decoding rate so that the same amount of data can be sent using fewer resources to reduce the CR to 10%. In another example, if the UE performs multiple transmissions, the UE can adjust the number of transmissions to adjust the CR, wherein reducing the number of transmissions can reduce the CR. In another example, the UE can reduce the CR by reducing the transmission rate (for example, to resolve congestion) by increasing the periodicity of the transmission and / or by reducing the number of HARQ retransmissions. The transmission rate is the rate at which the UE performs transmissions. For example, the UE can reduce the transmission rate to send once every 200 milliseconds instead of every 100 milliseconds to reduce congestion. In one aspect, the UE can perform the fifth aspect of the present disclosure after performing the fourth aspect of the present disclosure.

[0125] According to a sixth aspect of the present disclosure, CBR limit The CR may vary depending on the packet priority of the packet. In one aspect, the UE may calculate the CR based on the priority of the packet being sent. limit In one aspect, a higher CR limit It can be used for higher priority packets. For example, if the system supports packets of three priorities (p=0, 1, 2) (where p=0 is the highest priority), the UE can determine a different CBR for each of the different priorities. limit Specifically, the UE may determine the CBR for p=0 limit_p0 , determine CBR for p = 1 limit_p1 , determine CBR for p = 2 limit_p2 , among which, CBR limit_p2 <CBR limit_p1 <CBR limit_p0 (For example, CBR limit_p2 =0%, CBR limit_p1 =50%, CBR limit_p0 =80%). In this example, if the CBR increases above 30%, the UE may avoid sending packets with priority 2 (p=2). In one aspect, for example, a sixth aspect of the present disclosure may ensure that lower priority traffic may congest the system up to a low threshold (e.g., 30%) while still allowing the higher priority traffic to be successfully sent by allowing the higher priority traffic to congest the resources up to a high threshold (e.g., 80%).

[0126] According to a seventh aspect of the present disclosure, if the UE is sending packets with different priorities, the priority information of the packets may be considered as follows. When the UE has packets with different priorities for transmission, the UE may determine the CBR per priority level. limit and each priority CR limit Therefore, CBR limit and CR limit Varies based on priority. If the CBR is lower than the CBR for a particular priority limit , the UE can send packets with a specific priority. For example, if the CBR is lower than the CBR limit_p1 , then the UE can send packets with priority p1. However, if the CBR is greater than the CBR for low priority limit and less than the CBR for high priority limit , then the UE may send packets with high priority and may not send packets with low priority. For example, in CBR limit_p2 <CBR limit_p1 <CBR limit_p0 If CBR is lower than CBR limit_p2 , then the UE can send packets with priority p2 as well as packets with priority p1 and packets with priority p0. On the other hand, if CBR is greater than CBR limit_p1 And less than CBR limit_p0 , the UE may send packets with priority p0, but may not send packets with priority p1 or priority p2.

[0127] If packets with different priorities can be sent, the UE can send the packets according to at least one of the following options. According to the first option, the UE can first send all higher priority packets before sending lower priority packets. In one aspect, before transmission, the packets can be placed in different transmission queues based on different priorities. Therefore, the UE can clear the higher priority packet queue to prepare the higher priority packets for transmission before accessing the lower priority packet queue.

[0128] According to the second option, the UE may assign different weights to different priorities and may send packets of different priorities based on the weights. The per-priority weight w_p may define a portion of a packet with priority p to be sent. For example, if a packet has two priorities p1 and p2, with weights w_1=0.75 and w_2=0.25, respectively, then three p1 packets may be sent for each p2 packet. Based on the per-priority CBR limit, if the set of priorities that the UE may send is P={0,1,...,p-1}, then the weights for the priorities may be normalized so that the sum of the normalized weights is equal to 1 within the set P, based on: in, is the normalized weight for the priority. In an example where four priorities of packets are possible and w_0=0.6, w_1=0.2, w_2=0.15, w_3=0.05, when packets with priority p0 and priority p1 can be sent (e.g., P={0,1}), w_0 and w_1 can be normalized so that the sum of the normalized weights equals 1. Thus, in this example, normalized w_0=0.75 and normalized w_1=0.25, so that the sum of normalized w_0 and normalized w_1 is 1.

[0129] The systems and methods described herein relate to enhanced congestion control enhancements for D2D communications (including for aperiodic communications). The enhanced functionality may enable enhanced or improved operation in NR V2X mode. In some implementations, the systems and methods described herein implement congestion control based on a CR window that is more time-constrained than LTE. For example, the CR window may limit future usage estimates to currently scheduled or permitted aperiodic transmissions. Therefore, such systems and methods may better support aperiodic transmissions and may be used in URLLC mode.

[0130] Figure 5 An example of a wireless communication system 500 supporting D2D congestion control according to various aspects of the present disclosure is shown. In some examples, the wireless communication system 500 can implement various aspects of the wireless communication system 100. For example, the wireless communication system 500 may include a UE 115, a network entity 515 (e.g., a second UE), and optionally a second network entity 505 (e.g., a base station 105). Enhanced congestion control operations can enable sending more non-periodic communications, and thus can improve throughput and reduce latency. Such increased throughput and reduced latency can implement URLLC and can be used to improve reliability and throughput when there is congestion between devices.

[0131] The network entity 515 and the UE 115 may be configured to communicate via a frequency band, such as FR1 with a frequency of 410 to 7125 MHz or FR2 with a frequency of 24250 to 52600 MHz for millimeter waves. Note that for some data channels, the subcarrier spacing (SCS) may be equal to 15, 30, 60, or 120 kHz. The network entity 515 and the UE 115 may be configured to communicate via one or more component carriers (CCs), such as a representative first CC 581, a second CC 582, a third CC 583, and a fourth CC 584. Although four CCs are shown, this is for illustration only, and more or less than four CCs may be used. One or more CCs may be used to transmit control channel transmissions, data channel transmissions, and / or sidelink channel transmissions.

[0132] For example, sidelink channel transmission 556 may be sent between UE 115 and network entity 515. Alternatively, data and control channel transmissions 552 and 554 may be sent between UE 115 and second network entity 505. Such transmissions may include a physical downlink control channel (PDCCH), a physical downlink shared channel (PDSCH), a physical uplink control channel (PUCCH), a physical uplink shared channel (PUSCH), PSCCH, PSSCH, or PSFCH. Such transmissions may be scheduled via aperiodic grants and / or periodic grants.

[0133] Each periodic grant may have a corresponding configuration, such as configuration parameters / settings. A periodic grant configuration may include a configured grant (CG) configuration and settings. Additionally or alternatively, one or more periodic grants (e.g., their CGs) may have or be assigned to a CC ID, such as an expected CC ID.

[0134] Each CC may have a corresponding configuration, such as a configuration parameter / setting. The configuration may include bandwidth, bandwidth portion, HARQ process, TCI state, RS, control channel resources, data channel resources, or a combination thereof. Additionally or alternatively, one or more CCs may have or be assigned to a cell ID, a bandwidth portion (BWP) ID, or both. The cell ID may include a unique cell ID for the CC, a virtual cell ID, or a specific cell ID for a specific CC in multiple CCs. Additionally or alternatively, one or more CCs may have or be assigned to a HARQ ID. Each CC may also have corresponding management functions, such as beam management, BWP switching functions, or both. In some implementations, two or more CCs are quasi-co-located so that the CCs have the same beam and / or the same symbol.

[0135] In some implementations, the control information may be transmitted via the network entity 515 and the UE 115. For example, the control information may be transmitted using a MAC-CE transmission, an RRC transmission, a DCI transmission, another transmission, or a combination thereof.

[0136] UE 115 includes a processor 502, a memory 504, a transmitter 510, a receiver 512, an encoder 513, a decoder 514, a CR window determiner 516, a CR value determiner 517, and antennas 252a-r. Processor 502 may be configured to execute instructions stored at memory 504 to perform operations described herein. In some implementations, processor 502 includes or corresponds to controller / processor 280, and memory 504 includes or corresponds to memory 282. Memory 504 may also be configured to store CBR data 506, CR data 508, usage data 542, threshold 544, or a combination thereof, as further described herein.

[0137] The CBR data 506 includes or corresponds to data for a channel busy rate for one or more resources (such as a resource pool). The resource pool may include a side link channel, such as one or more of a PSCCH, a PSSCH, or a PSFCH. The CBR data 506 may include data indicating a CBR window (such as which subframes are in a given CBR window), indicating a CBR measurement value, or both. In some implementations, the CBR measurement value is a CBR value based on an emergency situation, such as a CBR value determined based on energy (e.g., RSSI). For example, if the RSSI is above a threshold, the resource is determined to be busy or used. The CBR may correspond to a ratio of busy resources to total resources.

[0138] CR data 508 includes or corresponds to data for channel occupancy for one or more resources. CR data 508 may include data indicating a CR window (such as which subframes are in a given CR window), indicating a CR measurement value, or both. The CR window may be determined based on usage data 542. Usage data 542 indicates usage history and estimated future usage. In a specific implementation, the CR window is determined based on estimated future usage limited to the current non-periodic transmission and its retransmission. The CR measurement value may be determined based on a CBR measurement value. For example, the CR measurement value may be determined based on a CBR value and one or more thresholds indicated by a threshold 554, and adjusted or evaluated.

[0139] In addition, CBR data 506 and CR data 508 may include setting data, such as window size or duration settings, window parameters, measurement parameters, etc. Such settings may be pre-set and / or RRC configurable. In addition, other related settings may be stored in memory 504, such as the number of retransmissions allowed and / or the timing of retransmissions.

[0140] The transmitter 510 is configured to send data to one or more other devices, and the receiver 512 is configured to receive data from one or more other devices. For example, the transmitter 510 can send data via a network (such as a wired network, a wireless network, or a combination thereof), and the receiver 512 can receive data via the network. For example, the UE 115 can be configured to send and / or receive data via the following: a direct device-to-device connection, a local area network (LAN), a wide area network (WAN), a modem-to-modem connection, the Internet, an intranet, an extranet, a cable transmission system, a cellular communication network, any combination of the above, or any other communication network now known or later developed that allows two or more electronic devices to communicate therein. In some implementations, the transmitter 510 and the receiver 512 can be replaced by a transceiver. Additionally or alternatively, the transmitter 510, the receiver 512, or both may include or correspond to reference Figure 2 One or more components of UE 115 are described.

[0141] The encoder 513 and the decoder 514 may be configured to encode and decode the data for transmission. The CR window determiner 516 may be configured to determine the window size and / or position of the CR window. For example, the CR window determiner 516 may be configured to determine the size and position of the subframe for the CR window. The CR value determiner 517 may be configured to determine and / or evaluate the CR value of one or more subframes for the CR window. For example, the CR value determiner 517 may be configured to determine the CR value of the subframe for the window and compare it with the corresponding CBR value to determine whether the CR value and / or one or more transmission parameters should be adjusted.

[0142] The network entity 515 includes a processor 530, a memory 532, a transmitter 534, a receiver 536, an encoder 535, a decoder 538, and antennas 234a-t. The processor 530 may be configured to execute instructions stored at the memory 532 to perform the operations described herein. In some implementations, the processor 530 includes or corresponds to the controller / processor 240, and the memory 532 includes or corresponds to the memory 242. The memory 532 may be configured to store the CBR data 506, the CR data 508, the usage data 542, the threshold 544, or a combination thereof, similar to the UE 115 and as further described herein.

[0143] The transmitter 534 is configured to send data to one or more other devices, and the receiver 536 is configured to receive data from one or more other devices. For example, the transmitter 534 can send data via a network (such as a wired network, a wireless network, or a combination thereof), and the receiver 536 can receive data via the network. For example, the network entity 515 can be configured to send and / or receive data via the following: a direct device-to-device connection, a local area network (LAN), a wide area network (WAN), a modem-to-modem connection, the Internet, an intranet, an extranet, a cable transmission system, a cellular communication network, any combination of the above, or any other communication network now known or later developed that allows two or more electronic devices to communicate therein. In some implementations, the transmitter 534 and the receiver 536 can be replaced by a transceiver. Additionally or alternatively, the transmitter 534, the receiver 536, or both may include or correspond to reference Figure 2 The encoder 535 and the decoder 538 may include the same functionality as described with reference to the encoder 513 and the decoder 514, respectively.

[0144] During operation of the wireless communication system 500, the network entity 515 and / or the second network entity 505 may determine that the UE 115 has enhanced congestion control capabilities. For example, the UE 115 may send a message 548 including an enhanced congestion control indicator 592. The indicator 592 may indicate enhanced congestion control capabilities or a particular type of enhanced congestion control, such as enhanced congestion control for NR V2X. In some implementations, the second network entity 505 sends control information to indicate to the UE 115 that enhanced congestion control is to be used. For example, in some implementations, the message 548 (or another message, such as a configuration transmission 550) is sent by the second network entity 505. The configuration transmission 550 may include or indicate the use of enhanced congestion control, or adjust or implement settings of enhanced congestion control, such as a window size or threshold.

[0145] During operation, the equipment of the wireless communication system 500 sends control, data and / or sidelink channel transmissions to other equipment of the wireless communication system 500. For example, UE 115 and base station (e.g., 505) can send control and data information on control and data channels. Multiple terminal devices or UEs can directly send control and data information to each other on one or more sidelink channels, and are independent of the base station of the wireless communication system 500. One or more of the terminal devices or UEs can perform congestion control operations. For example, UE 115 can track the use of one or more sidelink channel resources (such as PSCCH and PSSCH or PSCCH, PSSCH and PSFCH). In addition, UE 115 can estimate the use of one or more sidelink channel resources for future transmission. Future transmissions may include future retransmissions of current transmissions and (optionally) future transmissions and any retransmissions. In a specific implementation, future transmissions are limited to the last transmission of current transmissions or active transmissions (such as currently scheduled transmissions). In such an implementation, UE 115 may not consider or avoid considering future periodic transmissions.

[0146] Additionally, when using a set or configurable window size, limiting future transmissions may place greater emphasis on previous transmissions, and / or may extend the history to include a longer history of transmissions.

[0147] Based on the tracked usage history and estimated usage, the UE 115 can determine a CBR measurement value. The CBR measurement value can be associated with a specific CBR window. The size of the CBR window can be pre-set or configured by the devices of the wireless communication system 500.

[0148] In addition, UE 115 determines a CR window and a CR value. CR may be evaluated at a particular subframe (such as subframe n). The CR value may be determined based on the total number of subchannels used for previous transmissions and subchannels permitted for future subframes divided by the total number of configured subchannels within the considered window. For example, the window may be defined by how many transmissions and what type (previous or future) of transmissions are to be considered for CR calculation.

[0149] For example, the CR window determiner 516 determines the window for a particular subframe based on the window size, such as the position of the start subframe and the end subframe. For example, the CR window determiner 516 determines the position of the window based on an equation. As an illustrative, non-limiting example, the window position is determined based on the equation a+b+1=C, where a is a positive integer, b is 0 or a positive integer, and C is the size or duration of the CR window. In some implementations, C can be a number, such as 1000ms. In other implementations, C can be determined based on a formula, such as X multiplied by the size or duration of the CBR window. For example, C can be equal to 10 times the size of the CBR window. In a specific implementation, n+b should not exceed the last planned retransmission of the current transmission. Therefore, for a window of [na,n+b], the CR window start position and end position can be frame na and frame n+b. Therefore, the CR may be determined based on the total number of subchannels used for transmission in subframe [na,n-1] and permitted in subframe [n,n+b] divided by the total number of subchannels configured in the transmission pool in [na,n+b].

[0150] The CR value determiner 517 determines the CR value for a particular subframe (n) and window based on subchannel usage (such as described above) and based on the CBR value. For example, the CR value determiner 517 can determine the CR value based on subchannel usage as described above. The determined CR value can be adjusted based on the corresponding CBR value. For example, the determined CR value can be compared with one or more specific CBR thresholds (which are determined based on the CBR value). In a specific implementation, the CR value is adjusted based on the comparison, such as by a table or formula. The corresponding CBR value may include or correspond to a CBR value for a window similar to the CR value or for the same subframe.

[0151] UE 115 may perform congestion control based on the CR value. For example, UE 115 may adjust its subchannel usage based on the CR value. For example, UE 115 may adjust its subchannel usage for PSCCH and PSSCH with network entity 515 or for PSCCH, PSSCH, and PSFCH with network entity 515. As another example, UE 115 may adjust transmission settings based on the CR value.

[0152] therefore, Figure 5 Enhanced congestion control operations for D2D communications are described. When operating in D2D mode, improvements can be achieved using enhanced congestion control. Performing enhanced congestion control operations enables the network to reduce latency and improve reliability. The improved performance can increase throughput for communications on the network and enable the use of millimeter wave frequency ranges and URLLC mode.

[0153] Figure 6 is a block diagram illustrating example blocks executed by a UE configured according to one aspect of the present disclosure. Figure 8 UE 115 is shown to describe the example blocks. Figure 8 1 is a block diagram illustrating a UE 115 configured according to one aspect of the present disclosure. The UE 115 includes a Figure 2 1. The UE 115 of FIG. 1 shows the structure, hardware, and components of the UE 115. For example, the UE 115 includes a controller / processor 280 that operates to execute logic units or computer instructions stored in a memory 282 and controls the components of the UE 115 to provide the features and functions of the UE 115. Under the control of the controller / processor 280, the UE 115 sends and receives signals via wireless radio units 800a-r and antennas 252a-r. The wireless radio units 800a-r include the following: Figure 2 115, which includes modulators / demodulators 254a-r, MIMO detector 256, receive processor 258, transmit processor 264, and TX MIMO processor 266. Figure 8 As shown in the example of , the memory 282 stores D2D logic 802 (e.g., NR V2X logic), CBR logic 803, CR logic 804, feedback channel logic 805, usage data 806, and setting data 807.

[0154] At block 600, a mobile communication device (such as a UE) determines a CBR window for a channel busy rate (CBR) measurement for one or more resources. The UE (such as UE 115) receives and sends transmissions via wireless radio units 800a-r and antennas 252a-r, and records the use of transmissions and any future / scheduled transmissions. The one or more resources may include or correspond to a pool of resources, such as a resource pool. The one or more resources may include sidelink channel resources, such as PSCCH, PSSCH, PSFCH, etc.

[0155] Under the control of the controller / processor 280, the UE 115 may execute the D2D logic 802 stored in the memory 282. The execution environment of the D2D logic 802 provides the UE 115 with the functionality to define and execute congestion control procedures. In addition, the UE 115 may execute one or more of the CBR logic 803 and / or the CR logic 804. The execution environment of the D2D logic 802 (and optionally the CBR logic 803 and / or the CR logic 804) defines different congestion control procedures, such as determining a CBR window, a CBR value, a CR window, a CR value, or a combination thereof. For example, the UE 115 may determine the CBR window based on a set size or duration for the sidelink channel resources.

[0156] At block 601, UE 115 determines a CBR measurement value for a CBR window and for one or more resources. The CBR measurement value may be an energy-based CBR value, such as based on RSSI. For example, a resource may be determined to be occupied or busy based on an energy value exceeding a threshold energy value. UE 115 determines a CBR value for a sidelink channel resource and based on the sidelink channel resource, such as under the execution logic of D2D logic 802 and / or CBR logic 803.

[0157] At block 602, the UE 115 determines a channel occupancy (CR) window based on a first number of subframes used for a history of past transmissions and based on a second number of subframes used for future planned transmissions and corresponding retransmissions. For example, the UE 115 determines the amount of subframes used for the history and the amount of subframes used for future transmissions. For example, the UE 115 may determine to use a number X of subframes for future transmissions, where X corresponds to a subframe of the last retransmission of the current transmission. The UE 115 may then determine to use a number Y of subframes based on the number X and the size of the CR window.

[0158] At box 603, UE 115 determines a CR value for a CR window based on a subchannel used for one or more resources for a first number of subframes, and based on a subchannel estimated for one or more resources for a second number of subframes. In addition, UE 115 may determine a CR value based on a CBR value. For example, UE 115 determines a CR value based on a used subchannel and an available subchannel, and UE 115 may adjust the CR value based on a CBR value. UE 115 may perform congestion control operations as described herein based on a CR value and optionally CBR. For example, UE may adjust channel usage based on a CBR threshold, which is determined based on a CBR value. For example, one or more CBR thresholds with corresponding CR limits are set. Whenever the measured CBR reaches a threshold or satisfies a condition, UE checks whether its CR value is within the corresponding CR limit. If not, the CR value is adjusted, and congestion control may be performed.

[0159] In other implementations, the UE 115 may perform additional blocks (or the UE 115 may be configured to further perform additional operations). For example, the UE 115 may perform one or more of the operations described above. As another example, the UE 115 may perform one or more aspects as described below.

[0160] In a first aspect, a last transmission of the future planned transmissions is a last retransmission of a currently scheduled transmission.

[0161] In a second aspect, alone or in combination with the first aspect, determining the CR window includes avoiding consideration of future periodic transmissions scheduled by previously received periodic grants.

[0162] In a third aspect, alone or in combination with one or more of the above aspects, the CR value corresponds to a specific subframe of the CR window, and wherein determining the CR value comprises: determining, by the UE, a first number of subchannels used based on a first number of subframes historically used for past transmissions for the CR window, a second number of subchannels for determining the CR value based on a second number of subframes used for future planned transmissions and corresponding retransmissions for the CR window, and evaluating the specific subframe of the CR window based on a total number of configured subchannels available for one or more resources in the CR window.

[0163] In a fourth aspect, alone or in combination with one or more of the above aspects, future planned transmissions and corresponding retransmissions comprise retransmissions of currently scheduled transmissions, wherein the retransmissions occur within a packet delay budget from generation for each packet.

[0164] In a fifth aspect, alone or in combination with one or more of the above aspects, the maximum number of retransmissions is based on a HARQ feedback parameter.

[0165] In a sixth aspect, alone or in combination with one or more of the above aspects, the CR window is further determined based on a duration of a CBR measurement window.

[0166] In a seventh aspect, alone or in combination with one or more of the above aspects, the duration of the CR window is ten times the duration of the CBR measurement window.

[0167] In an eighth aspect, alone or in combination with one or more of the above aspects, the duration of the CR window is 1000 milliseconds.

[0168] In a ninth aspect, alone or in combination with one or more of the above aspects, the UE 115 sets a duration of a CBR window, a duration of a CR window, or both based on an RRC message.

[0169] In a tenth aspect, alone or in combination with one or more of the above aspects, the first number of subframes used for the history of past transmissions is greater than or equal to half the duration of the CR window.

[0170] In an eleventh aspect, alone or in combination with one or more of the above aspects, the first number of subframes used for the history of past transmissions is greater than or equal to 90% of the duration of the CR window.

[0171] In a twelfth aspect, alone or in combination with one or more of the above aspects, determining the CR window includes determining the CR window based on the following formula: the sum of the total number of used subchannels for subframe [na,n-1] and the total number of permitted subchannels for subframe [n,n+b] divided by the total number of configured subchannels for subframe [na,n+b], wherein a+b+1=C, wherein "a" corresponds to a first number of subframes for the history of past transmissions to be considered for the CR window, wherein "b" corresponds to a second number of subframes for future planned transmissions and corresponding retransmissions to be considered for the CR window, and wherein "C" is the duration of the CR window.

[0172] In a thirteenth aspect, alone or in combination with one or more of the above aspects, a first number of subframes for the history of past transmissions to be considered for the CR window is greater than or equal to half the duration of the CR window.

[0173] In a fourteenth aspect, alone or in combination with one or more of the above aspects, the sum of the current frame and the second number of subframes is less than or equal to the subframe number corresponding to the last retransmission of the current transmission.

[0174] In a fifteenth aspect, alone or in combination with one or more of the above aspects, determining a CBR measurement value includes: determining a received signal strength indicator (RSSI) value; comparing the RSSI value with a threshold; determining that a resource is busy based on the RSSI value exceeding the threshold; and determining the CBR measurement value based on the number of busy resources divided by the total number of resources in the CBR window.

[0175] In a sixteenth aspect, alone or in combination with one or more of the above aspects, the UE 115 determines the CBR measurement value independent of the PSFCH resource.

[0176] In a seventeenth aspect, alone or in combination with one or more of the above aspects, the UE 115 determines a second CBR measurement value for the PSFCH resource based on a second CBR window for the PSFCH resource.

[0177] In an eighteenth aspect, alone or in combination with one or more of the above aspects, the UE 115 determines a second CBR window for PSFCH resources based on an RRC configurable parameter or a preconfigured second CBR window duration.

[0178] In the nineteenth aspect, alone or in combination with one or more of the above aspects, determining a second CBR measurement value for PSFCH resources includes: determining a received signal strength indicator (RSSI) value for the PSFCH resources; comparing the RSSI value with a threshold; determining that resources in the PSFCH resources are busy based on the RSSI value exceeding the threshold; and determining a second CBR measurement value based on the number of busy resources divided by the total number of resources in the CBR window.

[0179] In a twentieth aspect, alone or in combination with one or more of the above aspects, the UE 115 further determines the CBR measurement value based on the PSFCH resource.

[0180] In a twenty-first aspect (alone or in combination with one or more of the above aspects), the CBR measurement value is for PSCCH, PSSCH, or both.

[0181] In a twenty-second aspect (alone or in combination with one or more of the above aspects), the CBR measurement values ​​are for PSCCH, PSSCH and PSFCH.

[0182] In a twenty-third aspect, alone or in combination with one or more of the above aspects, determining a CR value for a CR window based on a CBR measurement value comprises: selecting a CR value from a table based on the CBR measurement value; or calculating a CR value based on the CBR measurement value and a CR calculation formula.

[0183] In a twenty-fourth aspect, alone or in combination with one or more of the above aspects, the UE operates in a PSCCH / PSSCH multiplexing mode, and a single CBR measurement is performed for both PSCCH and PSSCH.

[0184] In a twenty-fifth aspect, either alone or in combination with one or more of the above aspects, UE 115 performs congestion control based on the CR value, wherein performing congestion control comprises one or more of: adjusting the amount of subchannels used for one or more resources, adjusting the amount of retransmissions, adjusting a modulation and coding scheme (MCS), or adjusting a communication channel frequency.

[0185] In a twenty-sixth aspect, alone or in combination with one or more of the above aspects, the UE is an autonomous vehicle configured for fifth generation wireless new radio (5G NR) vehicle-to-everything (V2X) communications.

[0186] Therefore, the UE and the base station can perform enhanced congestion control for the D2D mode. By performing enhanced congestion control for the D2D mode, latency and overhead can be reduced, and throughput and reliability can be improved.

[0187] Figure 7 is a block diagram illustrating example blocks executed by a UE configured according to one aspect of the present disclosure. Figure 8 The UE 115 is shown describing the example blocks. At block 700, a mobile communication device such as a UE determines a channel busy rate (CBR) window for CBR measurements for one or more resources. For example, the UE 115 determines the CBR window, similar to block 600.

[0188] At block 701 , the UE 115 determines a CBR measurement value for a CBR window and for one or more resources. The UE 115 determines the CBR value, similar to block 601 .

[0189] At block 702, the UE 115 determines a channel occupancy (CR) window based on the CBR measurement. For example, the UE 115 determines the size of the CR window based on the size of the CBR window. The size of the window may include or correspond to the duration of the window.

[0190] In other implementations, the UE 115 may perform additional blocks (or the UE 115 may be configured to further perform additional operations). For example, the UE 115 may perform one or more of the operations described above. As another example, the UE 115 may perform the operations described in reference to Figure 6 One or more aspects of a description.

[0191] Therefore, the UE and the base station can perform enhanced congestion control for the D2D mode. By performing enhanced congestion control for the D2D mode, additional functions can be achieved, such as congestion control can be performed using a dynamic or flexible window size (e.g., duration). Therefore, latency and overhead can be reduced, and throughput and reliability can be improved.

[0192] It will be understood by those skilled in the art that information and signals may be represented using any of a variety of different techniques and methods. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be mentioned throughout the above description may be represented by voltage, current, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0193] Figure 6 and Figure 7 The functional blocks and modules in may include: processors, electronic devices, hardware devices, electronic components, logical circuits, memories, software codes, firmware codes, etc., or any combination thereof.

[0194] The technician will also understand that the various illustrative logic boxes, modules, circuits and algorithm steps described in conjunction with the disclosure herein can be implemented as electronic hardware, computer software or a combination of the two. In order to clearly illustrate this interchangeability of hardware and software, various illustrative components, boxes, modules, circuits and steps have been generally described above around their functions. As for whether such functions are implemented as hardware or software, it depends on the specific application and the design constraints imposed on the entire system. The technician can implement the described functions in a variable manner for each specific application, but such implementation decisions should not be interpreted as causing departure from the scope of the present disclosure. The technician will also easily recognize that the order or combination of components, methods or interactions described herein are only examples, and the components, methods or interactions of various aspects of the present disclosure can be combined or performed in a manner different from the manner shown and described herein.

[0195] The various illustrative logic blocks, modules, and circuits described in conjunction with the disclosure herein may be implemented or executed using a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in an alternative manner, the processor may be any conventional processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices, for example, a combination of a DSP and a microprocessor, a plurality of microprocessors, a combination of one or more microprocessors with a DSP core, or any other such configuration.

[0196] The steps of the method or algorithm described in conjunction with the disclosure herein can be directly embodied in hardware, in a software module executed by a processor, or in a combination of the two. The software module can reside in a RAM memory, a flash memory, a ROM memory, an EPROM memory, an EEPROM memory, a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor so that the processor can read information from the storage medium and write information to the storage medium. In an alternative manner, the storage medium can be a component of the processor. The processor and the storage medium can reside in an ASIC. The ASIC can reside in a user terminal. In an alternative manner, the processor and the storage medium can exist in a user terminal as discrete components.

[0197] In one or more exemplary designs, the functions described can be implemented with hardware, software, firmware or any combination thereof. If implemented with software, the functions can be stored on a computer-readable medium or transmitted therethrough as one or more instructions or codes. Computer-readable media include both computer storage media and communication media, and the communication media include any media that facilitates the transfer of a computer program from one place to another. Computer-readable storage media can be any available medium that can be accessed by a general-purpose computer or a special-purpose computer. By way of example and not limitation, such computer-readable media can include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, disk storage or other magnetic storage devices, or any other medium that can be used for carrying or storing a desired program code unit in the form of an instruction or data structure and can be accessed by a general-purpose computer or a special-purpose computer or a general-purpose processor or a special-purpose processor. In addition, the connection can be appropriately referred to as a computer-readable medium. For example, if software is sent from a website, a server or other remote source using a coaxial cable, an optical fiber cable, a twisted pair or a digital subscriber line (DSL), the coaxial cable, the optical fiber cable, the twisted pair or the DSL are included in the definition of the medium. As used herein, disk and disc include compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray disc, wherein disks usually reproduce data magnetically, while discs usually reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media.

[0198] As used herein, including in the claims, the term "and / or," when used in a list of two or more items, means that any one of the listed items may be taken alone, or any combination of two or more of the listed items may be taken. For example, if a composition is described as containing components A, B, and / or C, the composition may contain: only A; only B; only C; a combination of A and B; a combination of A and C; a combination of B and C; or a combination of A, B, and C. Furthermore, as used herein, including in the claims, "or," as used in a list of items ending with "at least one of," indicates a disjunctive list, so that, for example, a list of "at least one of A, B, or C" means any of these items that are A or B or C or AB or AC or BC or ABC (i.e., A and B and C), or any combination thereof.

[0199] The foregoing description of the present disclosure is provided to enable any person skilled in the art to implement or use the present disclosure. Various modifications to the present disclosure will be apparent to those skilled in the art, and the general principles defined herein may be applied to other variations without departing from the spirit or scope of the present disclosure. Therefore, the present disclosure is not intended to be limited to the examples and designs described herein, but is to be given the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for wireless communication at a user equipment UE, comprising: Determining a CBR window for channel busy rate (CBR) measurement for one or more resources; determining a CBR measurement for the CBR window and for the one or more resources; Determining a channel occupancy rate (CR) window based on a first number of subframes used historically for past transmissions and based on a second number of subframes used for future scheduled transmissions and corresponding retransmissions, wherein the duration of the CR window does not exceed a subframe of a last scheduled retransmission of the future scheduled transmissions and corresponding retransmissions; determining a CR value for the CR window based on subchannels used for the one or more resources for the first number of subframes and based on subchannels estimated for the one or more resources for the second number of subframes; and A congestion control operation is performed based on the CR value.

2. The method according to claim 1, wherein: The last transmission of the future planned transmissions and corresponding retransmissions is a last retransmission of a currently scheduled transmission.

3. The method according to claim 1, wherein: Determining the CR window includes avoiding including future periodic transmissions scheduled by a previously received periodic grant in the second number of subframes.

4. The method according to claim 1, wherein: The CR value corresponds to a specific subframe of the CR window, and wherein determining the CR value comprises: The specific subframe of the CR window is evaluated based on a first number of subchannels used for the first number of subframes used for the historical use of the past transmissions for the CR window, a second number of subchannels used to determine the CR value based on the second number of subframes used for the future planned transmissions and corresponding retransmissions for the CR window, and based on a total number of configured subchannels available for the one or more resources in the CR window.

5. The method according to claim 1, wherein: The future planned transmissions and corresponding retransmissions include retransmissions of currently scheduled transmissions, wherein the retransmissions occur within a packet delay budget for each packet from generation of the currently scheduled transmission.

6. The method according to claim 1, wherein: The maximum number of retransmissions is based on the HARQ feedback parameters.

7. The method according to claim 1, wherein: The CR window is further determined based on a duration of the CBR window.

8. The method according to claim 7, wherein: The duration of the CR window is ten times the duration of the CBR window.

9. The method according to claim 1, wherein: The CBR measurements are for the Physical Sidelink Control Channel (PSCCH), the Physical Sidelink Shared Channel (PSSCH) and the Physical Sidelink Feedback Channel (PSFCH).

10. The method according to claim 1, wherein: Determining the CR value for the CR window based on the CBR measurement value includes: Selecting the CR value from a table based on the CBR measurement; or The CR value is calculated based on the CBR measurement value and a CR calculation formula.

11. The method according to claim 1, wherein: The UE operates in a physical sidelink control channel (PSCCH) / physical sidelink shared channel (PSSCH) multiplexing mode, and wherein a single CBR measurement is performed for both the PSCCH and the PSSCH.

12. The method according to claim 1, wherein: Performing the congestion control operation based on the CR value includes: Perform one or more operations including: adjusting the amount of subchannels used for the one or more resources, adjusting the amount of retransmissions, adjusting a modulation and coding scheme (MCS), adjusting a communication channel frequency, avoiding sending communications during the CBR window, or a combination thereof.

13. The method according to claim 1, wherein: The future planned transmission and corresponding retransmission include a current planned transmission and a corresponding retransmission of the current planned transmission, and further include: receiving a scheduling message for the future planned transmission and corresponding retransmission before determining the CR window and the CR value, Prior to determining the CR window and the CR value, the future planned transmissions and corresponding retransmissions are determined based on the scheduling message.

14. The method according to claim 1, wherein: The first number of subframes for the history of past transmissions is greater than or equal to half the duration of the CR window, and wherein the sum of the subframe number for a current subframe and the second number of subframes is less than or equal to the subframe number corresponding to the last scheduled retransmission.

15. An apparatus configured for wireless communication at a user equipment (UE), the apparatus comprising: one or more processors; as well as a memory coupled to the one or more processors, wherein instructions are stored in the memory and executable by the one or more processors to cause the apparatus to: Determining a CBR window for channel busy rate (CBR) measurement for one or more resources; determining a CBR measurement for the CBR window and for the one or more resources; Determining a channel occupancy rate (CR) window based on a first number of subframes used historically for past transmissions and based on a second number of subframes used for future scheduled transmissions and corresponding retransmissions, wherein the duration of the CR window does not exceed a subframe of a last scheduled retransmission of the future scheduled transmissions and corresponding retransmissions; determining a CR value for the CR window based on subchannels used for the one or more resources for the first number of subframes and based on subchannels estimated for the one or more resources for the second number of subframes; and A congestion control operation is performed based on the CR value.

16. The device according to claim 15, wherein: The duration of the CR window is 1000 milliseconds, and wherein the future scheduled transmissions and corresponding retransmissions include aperiodic transmissions, periodic transmissions, or both.

17. The device according to claim 15, wherein: The instructions are also executable by the one or more processors to cause the apparatus to: set a duration of the CBR window, the duration of the CR window, or both based on a radio resource control (RRC) message.

18. The device according to claim 15, wherein: The first number of subframes of the history of past transmissions is greater than or equal to half the duration of the CR window, and wherein the future planned transmissions and corresponding retransmissions represent actual scheduled transmissions or retransmissions that occur after the CR window and the CR value are determined.

19. The device according to claim 15, wherein: The instructions for determining the CR window also include instructions that can be executed by the one or more processors to cause the device to: determine the CR window based on the following formula: the sum of the total number of used subchannels for subframe [na,n-1] and the total number of permitted subchannels for subframe [n,n+b] divided by the total number of configured subchannels for subframe [na,n+b], wherein a+b+1=C, wherein "a" corresponds to the first number of subframes for the history of past transmissions to be considered for the CR window, wherein "b" corresponds to the second number of subframes for the future planned transmissions and corresponding retransmissions to be considered for the CR window, and wherein "C" is the duration of the CR window.

20. The device according to claim 19, wherein The first number of subframes for the history of past transmissions to be considered for the CR window is greater than or equal to half the duration of the CR window, and wherein a sum of a current frame and the second number of subframes is less than or equal to a subframe number corresponding to a last retransmission of a current transmission.

21. The device according to claim 15, wherein: The instructions to determine the CBR measurement also include instructions executable by the one or more processors to cause the apparatus to: Determining a received signal strength indicator RSSI value; Comparing the RSSI value with a threshold; determining that a resource is busy based on the RSSI value exceeding the threshold; as well as The CBR measure is determined based on the number of busy resources divided by the total number of resources in the CBR window.

22. The device according to claim 15, wherein: The instructions may also be executed by the one or more processors to cause the apparatus to: The CBR measurement is determined independent of a physical sidelink feedback channel (PSFCH) resource.

23. The device according to claim 15, wherein: The instructions may also be executed by the one or more processors to cause the apparatus to: A second CBR measurement value for a physical sidelink feedback channel (PSFCH) resource is determined based on a second CBR window for the PSFCH resource.

24. The device according to claim 23, wherein: The instructions may also be executed by the one or more processors to cause the apparatus to: The second CBR window for the PSFCH resource is determined based on an RRC configurable parameter or a preconfigured second CBR window duration.

25. The device according to claim 23, wherein: The instructions to determine the second CBR measurement value for the PSFCH resource also include instructions executable by the one or more processors to cause the apparatus to: Determining a received signal strength indicator, RSSI, value for the PSFCH resource; Comparing the RSSI value with a threshold; Determining that a resource in the PSFCH resource is busy based on the RSSI value exceeding the threshold; as well as The second CBR measurement is determined based on the number of busy resources divided by the total number of resources in the CBR window.

26. The device according to claim 15, wherein: The instructions may also be executed by the one or more processors to cause the apparatus to: The CBR measurement is further determined based on a physical sidelink feedback channel (PSFCH) resource.

27. The device according to claim 15, wherein: The CBR measurement is for a physical sidelink control channel (PSCCH), a physical sidelink shared channel (PSSCH), or both.

28. The device according to claim 15, wherein: The instructions to perform the congestion control operation based on the CR value also include instructions executable by the one or more processors to cause the apparatus to: Perform one or more operations including: adjusting the amount of subchannels used for the one or more resources, adjusting the amount of retransmissions, adjusting a modulation and coding scheme (MCS), adjusting a communication channel frequency, avoiding sending communications during the CBR window, or a combination thereof.

29. A non-transitory computer readable medium having program code recorded thereon for wireless communication at a user equipment (UE), the program code comprising: Program code executable by a computer for causing the computer to determine a CBR window for a channel busy rate (CBR) measurement for one or more resources; program code executable by a computer for causing the computer to determine a CBR measurement for the CBR window and for the one or more resources; program code executable by a computer to cause the computer to determine a channel occupancy rate (CR) window based on a first number of subframes used historically for past transmissions and based on a second number of subframes used for future scheduled transmissions and corresponding retransmissions, wherein the duration of the CR window does not exceed a subframe of a last scheduled retransmission of the future scheduled transmissions and corresponding retransmissions; program code executable by a computer to cause the computer to determine a CR value for the CR window based on subchannels used for the one or more resources for the first number of subframes and based on subchannels estimated for the one or more resources for the second number of subframes; and Program code executable by a computer for causing the computer to perform a congestion control operation based on the CR value.

30. The non-transitory computer readable medium of claim 29, wherein: The CBR measurements are for PSCCH, Physical Sidelink Shared Channel (PSSCH) and Physical Sidelink Feedback Channel (PSFCH).

31. The non-transitory computer readable medium of claim 29, wherein: The program code for causing the computer to determine the CR value for the CR window based on the CBR measurement value includes: program code executable by a computer for causing the computer to select the CR value from a table based on the CBR measurement; or Program code executable by a computer for causing the computer to calculate the CR value based on the CBR measurement value and a CR calculation formula.

32. The non-transitory computer readable medium of claim 29, wherein: The UE operates in a physical sidelink control channel (PSCCH) / physical sidelink shared channel (PSSCH) multiplexing mode, and wherein a single CBR measurement is performed for both the PSCCH and the PSSCH.

33. The non-transitory computer readable medium of claim 29, the program code further comprising: Program code executable by a computer to cause the computer to perform congestion control based on the CR value, wherein performing the congestion control comprises one or more of: adjusting the amount of subchannels used for the one or more resources, adjusting the amount of retransmissions, adjusting a modulation and coding scheme (MCS), or adjusting a communication channel frequency.

34. The non-transitory computer readable medium of claim 29, wherein: The UE includes an autonomous vehicle configured for fifth generation wireless new radio (5G NR) vehicle-to-everything (V2X) communications.

35. An apparatus configured for wireless communication at a user equipment (UE), the apparatus comprising: one or more processors; as well as a memory coupled to the one or more processors, wherein instructions are stored in the memory and executable by the one or more processors to cause the apparatus to: Determining a CBR window for channel busy rate (CBR) measurement for one or more resources; determining a CBR measurement for the CBR window and for the one or more resources; Determining a channel occupancy rate (CR) window based on a first number of subframes used historically for past transmissions and based on a second number of subframes used for future scheduled transmissions and corresponding retransmissions, wherein the duration of the CR window does not exceed a subframe of a last scheduled retransmission of the future scheduled transmissions and corresponding retransmissions; determining a CR value for the CR window based on subchannels used for the one or more resources for the first number of subframes and based on subchannels estimated for the one or more resources for the second number of subframes; and Communications are avoided from being sent during the CBR window based on the CR value.

36. An apparatus configured for wireless communication at a user equipment (UE), the apparatus comprising: means for determining a CBR window for channel busy rate (CBR) measurement for one or more resources; means for determining a CBR measurement for the CBR window and for the one or more resources; means for determining a channel occupancy rate (CR) window based on a first number of subframes used historically for past transmissions and based on a second number of subframes used for future scheduled transmissions and corresponding retransmissions, wherein the duration of the CR window does not exceed a subframe of a last scheduled retransmission of the future scheduled transmissions and corresponding retransmissions; means for determining a CR value for the CR window based on subchannels used for the one or more resources for the first number of subframes and based on subchannels estimated for the one or more resources for the second number of subframes; and Means for performing congestion control operations based on the CR value.

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