User equipment autonomous resource selection

Abstract

Some aspects of the present disclosure provide techniques for user equipment (UE) autonomous sidelink resource selection. A method that can be performed by a UE includes performing autonomous sidelink resource selection. The selection includes excluding, from a first set of resources, resources associated with transmissions having a signal strength above a signal strength threshold to form a second set of resources. The selection includes determining an amount of resources in the second set of resources is equal to or above a threshold percentage of an amount of resources in the first set of resources. The selection includes excluding, from the second set of resources, resources associated with a physical sidelink control channel (PSCCH) without excluding resources associated with a physical sidelink shared channel associated with the PSCCH to form a third set of resources. The selection includes randomly selecting a resource for a PSCCH transmission from the third set of resources. The method includes transmitting the PSCCH transmission using the randomly selected resource.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to U.S. Application No. 17 / 165,804, filed February 2, 2021, the entire contents of which are expressly incorporated herein by reference as fully listed below and used for all applicable purposes. Technical Field

[0003] Various aspects of this disclosure relate to wireless communications, and more specifically, to user equipment (UE) autonomous resource selection techniques for the physical side link control channel (PSCCH). Background Technology

[0004] Wireless communication systems are widely deployed to provide various telecommunications services, such as telephone, video, data, messaging, and broadcasting. These wireless communication systems can employ multiple access technologies that enable communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, etc.). Examples of such multiple access systems include 3GPP Long Term Evolution (LTE) systems, LTE-A Advanced systems, Code Division Multiple Access (CDMA) systems, Time Division Multiple Access (TDMA) systems, Frequency Division Multiple Access (FDMA) systems, Orthogonal Frequency Division Multiple Access (OFDMA) systems, Single Carrier Frequency Division Multiple Access (SC-FDMA) systems, and Time Division Synchronous Code Division Multiple Access (TD-SCDMA) systems.

[0005] These multiple access technologies have been adopted in various telecommunications standards to provide a universal protocol enabling different wireless devices to communicate at the city, national, regional, and even global levels. An example of emerging telecommunications standards is new radio (e.g., 5G NR). NR is a set of enhancements within the LTE mobile standard issued by 3GPP. NR aims to better support mobile broadband internet access by using OFDMA with a cyclic prefix (CP) on both the downlink (DL) and uplink (UL), thereby improving spectrum efficiency, reducing costs, improving service, utilizing new spectrum, and better integrating with other open standards. To this end, NR supports beamforming, multiple-input multiple-output (MIMO) antenna technology, and carrier aggregation.

[0006] However, with the increasing demand for mobile broadband access, further improvements to NR and LTE technologies are needed. Preferably, these improvements should be applicable to other multiple access technologies and telecommunications standards that employ these technologies. Summary of the Invention

[0007] The systems, methods, and apparatuses of this disclosure each have several aspects, and none of these aspects is solely responsible for their intended properties. Without limiting the scope of this disclosure as set forth in the appended claims, some features will now be briefly discussed. Upon consideration of this discussion, and particularly after reading the section entitled "Detailed Description," it will be understood how the features of this disclosure provide various advantages, including improved User Equipment (UE) autonomous resource selection for the Physical Side Link Control Channel (PSCCH).

[0008] Certain aspects of the subject matter described in this disclosure can be implemented in a wireless communication method via a UE. The method generally includes performing autonomous sidelink resource selection. The autonomous sidelink resource selection includes excluding one or more resources associated with transmissions having a signal strength higher than a first signal strength threshold from a first resource set to form a second resource set. The autonomous sidelink resource selection includes determining that the amount of resources in the second resource set is equal to or higher than a threshold percentage of the amount of resources in the first resource set. The autonomous sidelink resource selection includes excluding one or more resources associated with one or more Physical Sidelink Shared Channels (PSSCHs) associated with the one or more PSCCHs from the second resource set without excluding one or more resources associated with one or more Physical Sidelink Shared Channels (PSSCHs) associated with the one or more PSCCHs to form a third resource set containing the unexcluded resources from the second resource set. The autonomous sidelink resource selection includes randomly selecting one or more resources from the third resource set for PSCCH transmission. The method generally includes using the randomly selected one or more resources to transmit the PSCCH transmission.

[0009] Certain aspects of the subject matter described in this disclosure can be implemented in an apparatus for wireless communication. The apparatus generally includes at least one processor and a memory coupled to the at least one processor. The memory typically includes code executable by the at least one processor to cause the apparatus to perform autonomous sidelink resource selection. The autonomous sidelink resource selection includes excluding one or more resources associated with transmissions having a signal strength higher than a first signal strength threshold from a first resource set to form a second resource set. The autonomous sidelink resource selection includes determining that the amount of resources in the second resource set is equal to or higher than a threshold percentage of the amount of resources in the first resource set. The autonomous sidelink resource selection includes excluding one or more resources associated with one or more PSCCHs from the second resource set without excluding one or more resources associated with one or more PSSCHs associated with the one or more PSCCHs to form a third resource set. The autonomous sidelink resource selection includes randomly selecting one or more resources from the third resource set for PSCCH transmission. The memory typically includes code executable by the at least one processor to cause the apparatus to transmit PSCCH transmissions using the randomly selected one or more resources.

[0010] Certain aspects of the subject matter described in this disclosure can be implemented in an apparatus for wireless communication. The apparatus typically includes components for performing autonomous sidelink resource selection. The components for performing autonomous sidelink resource selection include components for excluding one or more resources associated with transmissions having signal strengths higher than a first signal strength threshold from a first resource set to form a second resource set. The components for performing autonomous sidelink resource selection include components for determining that the amount of resources in the second resource set is equal to or higher than a threshold percentage of the amount of resources in the first resource set. The components for performing autonomous sidelink resource selection include components for excluding one or more resources associated with one or more PSCCHs from the second resource set, without excluding one or more resources associated with one or more PSSCHs associated with the one or more PSCCHs, to form a third resource set. The components for performing autonomous sidelink resource selection include components for randomly selecting one or more resources from the third resource set for PSCCH transmission. The apparatus typically includes components for transmitting PSCCH transmissions using the randomly selected one or more resources.

[0011] Certain aspects of the subject matter described in this disclosure can be implemented in a computer-readable medium for wireless communication having computer-executable code stored thereon. The computer-readable medium typically includes code for performing autonomous sidelink resource selection. The code for performing autonomous sidelink resource selection includes code for excluding one or more resources associated with transmissions having a signal strength higher than a first signal strength threshold from a first resource set to form a second resource set. The code for performing autonomous sidelink resource selection includes code for determining that the amount of resources in the second resource set is equal to or higher than a threshold percentage of the amount of resources in the first resource set. The code for performing autonomous sidelink resource selection includes code for excluding one or more resources associated with one or more PSCCHs from the second resource set to form a third resource set without excluding one or more resources associated with one or more PSSCHs associated with the one or more PSCCHs. The code for performing autonomous sidelink resource selection includes code for randomly selecting one or more resources from the third resource set for PSCCH transmission. The computer-readable medium typically includes code for transmitting PSCCH transmissions using the randomly selected one or more resources.

[0012] To achieve the foregoing and related objectives, one or more aspects include the features fully described below and specifically pointed out in the claims. The following description and drawings set forth certain illustrative features of one or more aspects in detail. However, these features indicate only a few of the many ways in which the principles of each aspect can be employed. Attached Figure Description

[0013] To gain a more detailed understanding of the foregoing features of this disclosure, the brief overview described above can be described in more specific terms by referring to several aspects, some of which are illustrated in the accompanying drawings. However, it should be noted that the drawings illustrate only some typical aspects of this disclosure and should not be construed as limiting its scope, as other equally valid aspects are acceptable in this specification.

[0014] Figure 1 This is a block diagram conceptually illustrating an exemplary wireless communication network according to some aspects of this disclosure.

[0015] Figure 2 This is a block diagram conceptually illustrating an exemplary base station (BS) and user equipment (UE) design according to some aspects of this disclosure.

[0016] Figure 3 This is an exemplary frame format for certain wireless communication systems (e.g., New Radio (NR)) according to some aspects of this disclosure.

[0017] Figure 4An exemplary vehicle-to-everything (V2X) communication system is shown in accordance with some aspects of this disclosure.

[0018] Figure 5 Another exemplary V2X communication system is shown in accordance with some aspects of this disclosure.

[0019] Figure 6 This is a parameter table for sidelink transmission in a C-V2X system, based on some aspects of this disclosure.

[0020] Figure 7A and Figure 7B Exemplary conflicts in congestion scenarios are shown in accordance with some aspects of this disclosure.

[0021] Figure 8A Exemplary conflicts in cellular V2X (C-V2X) direct communication between a UE and some aspects thereof are shown in this disclosure.

[0022] Figure 8B An exemplary overlap of a UE in C-V2X direct communication is shown according to some aspects of this disclosure.

[0023] Figure 9 Exemplary side link control information (SCI) transmission and retransmission are shown in accordance with some aspects of this disclosure.

[0024] Figure 10 It is a decision tree diagram illustrating the autonomous resource reselection process according to various aspects of this disclosure.

[0025] Figure 11 This is a flowchart illustrating exemplary operation of wireless communication via a UE according to various aspects of this disclosure.

[0026] Figure 12 This is a flowchart illustrating exemplary signaling for transmitting the Physical Sidelink Control Channel (PSCCH) using UE autonomous sidelink resource selection, according to various aspects of this disclosure.

[0027] Figure 13 A communication device according to this disclosure is shown, which may include various components configured to operate according to the techniques disclosed herein.

[0028] For ease of understanding, the same reference numerals are used where possible to denote the same elements common to all the figures. Elements disclosed in one aspect are intended to be usefully applied to other aspects without specific description. Detailed Implementation

[0029] Various aspects of this disclosure provide apparatus, methods, processing systems, and computer-readable media for bypassing the selection of Physical Side Link Control Channel (PSCCH) resources in User Equipment (UE) autonomous resource selection.

[0030] In cellular vehicle-to-everything (C-V2X) systems, user equipment (UEs), such as in-vehicle UEs, can communicate directly with each other using time-frequency resources chosen autonomously by the UE. However, when two UEs choose the same resource, the autonomous selection of resources may cause problems, resulting in data packet collisions or data packet overlaps.

[0031] The aspects of this disclosure can help to better perform the autonomous resource selection process. In some examples, the UE can exclude additional PSCCH resources during autonomous resource selection and can reduce the likelihood of its PSCCH transmissions conflicting with another transmission. In some aspects, the UE can adjust the modulation and coding scheme (MCS) and / or the amount of resources selected for transmission to further reduce conflicts and overlaps with another transmission.

[0032] The following description provides examples of avoiding the selection of PSCCH resources during UE autonomous resource selection in a communication system, and does not limit the scope, applicability, or examples specified in the claims. Changes may be made to the function and arrangement of the elements discussed without departing from the scope of this disclosure. Various processes or components may be omitted, substituted, or added as appropriate in various examples. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Furthermore, features described with respect to some examples may be combined in some other examples. For example, an apparatus or method may be implemented using any number of aspects set forth herein. Furthermore, the scope of this disclosure is intended to cover apparatus or methods implemented using other structures, functions, or structures and functions that are alternative to or appended to the various aspects of this disclosure set forth herein. It should be understood that any aspect of this disclosure disclosed herein may be implemented by one or more elements of the claims. The word “exemplary” is used herein to mean “as an example, instance, or illustration.” Any aspect described herein as “exemplary” is not necessarily to be construed as preferred or superior to other aspects.

[0033] Typically, any number of wireless networks can be deployed in a given geographical area. Each wireless network can support a specific Radio Access Technology (RAT) and can operate on one or more frequencies. A RAT can also be referred to as a radio technology, air interface, etc. A frequency can also be referred to as a carrier, subcarrier, channel, frequency modulation, subband, etc. Each frequency can support a single RAT within a given geographical area to avoid interference between wireless networks using different RATs.

[0034] The techniques described herein can be used in a variety of wireless network and radio technologies. Although the various aspects may be described herein using terms commonly associated with 3G, 4G and / or newer radios (e.g., 5G NR), the various aspects of this disclosure can be applied to other generation-based communication systems.

[0035] NR access can support a variety of wireless communication services, such as enhanced mobile broadband (eMBB) for wide bandwidth, millimeter wave (mmW), massive machine-type communication (mMTC) for non-backward-compatible MTC technologies, and / or mission-critical ultra-reliable low-latency communication (URLLC). These services may include latency and reliability requirements. These services may also have different transmission time intervals (TTIs) to meet their respective quality of service (QoS) requirements. Furthermore, these services can coexist in the same subframe.

[0036] NR supports beamforming and allows dynamic configuration of beam direction. It also supports precoded MIMO transmission. MIMO configuration in DL can support up to 8 transmit antennas, executing up to 8 streams, with up to 2 streams per UE in multi-layer DL transmission. Multi-layer transmission with 2 streams per UE is supported. Up to 8 serving cells can be used to support aggregation of multiple cells.

[0037] Figure 1 An exemplary wireless communication network 100 is shown in which aspects of this disclosure may be implemented. For example, the wireless communication network 100 may be an NR system (e.g., a 5G NR network). Figure 1 As shown, the wireless communication network 100 can communicate with the core network 132. The core network 132 can communicate with one or more base stations (BS) 110a-z (each also individually referred to herein as BS 110 or collectively as BS 110) and / or user equipment (UE) 120a-y (each also individually referred to herein as UE 120 or collectively as UE 120) in the wireless communication network 100 via one or more interfaces.

[0038] Depending on certain aspects, UE 120 can be configured to avoid selecting PSCCH resources during UE autonomous resource selection. For example... Figure 1As shown, UE 120a includes a sidelink manager 122. The sidelink manager 122 can be configured to perform autonomous sidelink resource selection. When performing the autonomous sidelink resource selection, the sidelink manager 122 can be configured to exclude one or more resources associated with transmissions whose signal strength is higher than a first signal strength threshold from a first resource set to form a second resource set. When performing the autonomous sidelink resource selection, the sidelink manager 122 can be configured to determine that the amount of resources in the second resource set is equal to or higher than a threshold percentage of the amount of resources in the first resource set. When performing the autonomous sidelink resource selection, the sidelink manager 122 can be configured to exclude one or more resources associated with one or more Physical Sidelink Shared Channels (PSSCHs) associated with the one or more Physical Sidelink Control Channels (PSCCHs) from the second resource set to form a third resource set without excluding one or more resources associated with one or more Physical Sidelink Shared Channels (PSSCHs) associated with the one or more Physical Sidelink Control Channels (PSCCHs). When performing the autonomous sidelink resource selection, the sidelink manager 122 can be configured to randomly select one or more resources from the third resource set for PSCCH transmission. Side link manager 122 can be configured to send PSCCH transmissions using one or more randomly selected resources according to various aspects of this disclosure. UE 120b may include side link manager 124, which can be configured to perform operations corresponding to side link manager 122.

[0039] BS 110 can provide communication coverage for a specific geographic area, sometimes referred to as a "cell," which can be stationary or mobile depending on the location of the moving BS 110. In some instances, BS 110s can interconnect with each other and / or with one or more other BSs or network nodes (not shown) in wireless network 100 using any suitable transport network via various types of backhaul interfaces (e.g., direct physical connection, wireless connection, virtual network, etc.). Figure 1 In the example shown, BS 110a, 110b, and 110c can be macro BSs for macro cells 102a, 102b, and 102c, respectively. BS 110x can be a pico BS for pico cell 102x. BS 110y and 110z can be femto BSs for femto cells 102y and 102z, respectively. A BS can support one or more cells.

[0040] BS 110 communicates with UE 120 in the wireless communication network 100. UE 120 (e.g., 120x, 120y, etc.) may be distributed throughout the wireless communication network 100, and each UE 120 may be fixed or mobile. The wireless communication network 100 may also include relay stations (e.g., relay station 110r), also referred to as relays, which receive transmissions of data and / or other information from upstream stations (e.g., BS 110a or UE 120r) and transmit transmissions of data and / or other information to downstream stations (e.g., UE 120 or BS 110), or relay transmissions between UE 120 to facilitate communication between devices.

[0041] Network controller 130 can communicate with a group of BS110s and provide coordination and control for these BS110s (e.g., via backhaul). In various aspects, network controller 130 can communicate with core network 132 (e.g., a 5G core network (5GC)) which provides various network functions such as access and mobility management, session management, user plane functions, policy control functions, authentication server functions, unified data management, application functions, network public functions, network repository functions, network slice selection functions, etc.

[0042] Figure 2 Exemplary components (e.g., BS 110a and UE 120a) that can be used to implement various aspects of this disclosure are shown. Figure 1 Wireless communication network 100).

[0043] On BS 110a, the transmitting 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 the Physical Broadcast Channel (PBCH), Physical Control Format Indicator Channel (PCFICH), Physical Hybrid ARQ Indicator Channel (PHICH), Physical Downlink Control Channel (PDCCH), Group Common PDCCH (GC PDCCH), etc. The data can be used for the Physical Downlink Shared Channel (PDSCH), etc. The Media Access Control (MAC)-Control Element (MAC-CE) is a MAC layer communication structure that can be used for exchanging control commands between wireless nodes. The MAC-CE can be carried in a shared channel such as the Physical Downlink Shared Channel (PDSCH), Physical Uplink Shared Channel (PUSCH), or Physical Sidelink Shared Channel (PSSCH).

[0044] Processor 220 can process (e.g., encode and symbol map) data and control information to obtain data symbols and control symbols, respectively. The transmit processor 220 can also generate reference symbols, such as for the primary synchronization signal (PSS), secondary synchronization signal (SSS), PBCH demodulation reference signal (DMRS), and channel state information reference signal (CSI-RS). If applicable, 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, and can provide an output symbol stream to the modulators (MODs) in transceivers 232a-232t. Each modulator in transceivers 232a-232t can process its corresponding output symbol stream (e.g., for OFDM, etc.) to obtain an output sample stream. Each modulator can further process (e.g., convert to analog, amplify, filter, and up-convert) the output sample stream to obtain a downlink signal. Downlink signals from the modulators in transceivers 232a-232t can be transmitted via antennas 234a-234t respectively.

[0045] In UE 120a, antennas 252a-252r can receive downlink signals from BS 110a and / or sidelink signals from UE 120b, and can provide the received signals to demodulators (DEMODs) in transceivers 254a-254r respectively. Each demodulator in transceivers 254a-254r can adjust (e.g., filter, amplify, downconvert, and digitize) the corresponding received signal to obtain an input sample. Each demodulator can further process the input sample (e.g., for OFDM, etc.) to obtain the received symbols. MIMO detector 256 can obtain the received symbols from all demodulators in transceivers 254a-254r, perform MIMO detection on the received symbols where applicable, and provide the detected symbols. Receiver processor 258 can process (e.g., demodulate, deinterleave, and decode) the detected symbols, provide decoded data for UE 120a to data sink 260, and provide decoded control information to controller / processor 280.

[0046] On the uplink and / or sidelink, in UE 120a, the transmit processor 264 can receive and process data from the data source 262 (e.g., for the Physical Uplink Shared Channel (PUSCH) and / or the Physical Sidelink Shared Channel (PSSCH)) and control information from the controller / processor 280 (e.g., for the Physical Uplink Control Channel (PUCCH) and / or the Physical Sidelink Control Channel (PSCCH)). The transmit processor 264 can also generate reference symbols for reference signals (e.g., for sounding reference signals (SRS)). The symbols from the transmit processor 264 can be pre-encoded by the TXMIMO processor 266 where applicable, further processed by the demodulators in transceivers 254a-254r (e.g., for SC-FDM, etc.), and transmitted to BS 110a and / or UE 120b. In BS 110a, the uplink signal from UE 120a can be received by antenna 234, processed by the modulator in transceivers 232a-232t, detected by MIMO detector 236 where applicable, and further processed by receiver processor 238 to obtain decoded data and control information transmitted by UE 120a. Receiver processor 238 can provide the decoded data to data sink 239 and the decoded control information to controller / processor 240.

[0047] Memory 242 and 282 can store data and program code of BS 110a and UE 120a, respectively. Scheduler 244 can schedule UE for data transmission on the downlink and / or uplink.

[0048] The antenna 252, processors 266, 258, 264, and / or controller / processor 280 of UE120a can be used to perform the various techniques and methods described herein. For example, such as Figure 2 As shown, the controller / processor 280 of UE 120a has a sidelink manager 281, which can be configured to avoid selecting PSCCH resources in UE autonomous resource selection according to the aspects described herein. Although the illustration is shown at the controller / processor, the operations described herein can be performed using other components of UE 120a and BS 110a.

[0049] NR can use Orthogonal Frequency Division Multiplexing (OFDM) with a cyclic prefix (CP) on both the uplink and downlink. NR can support half-duplex operation using Time Division Duplex (TDD). OFDM and Single-Carrier Frequency Division Multiplexing (SC-FDM) divide the system bandwidth into multiple orthogonal subcarriers, which are often also called tones, bins, etc. Each subcarrier can be modulated using data. Modulation symbols can be transmitted in the frequency domain using OFDM and in the time domain using SC-FDM. The spacing between adjacent subcarriers can be fixed, and the total number of subcarriers can depend on the system bandwidth. The minimum resource allocation, called a resource block (RB), can be 12 consecutive subcarriers. The system bandwidth can also be divided into subbands. For example, a subband can cover multiple RBs. NR can support a basic subcarrier spacing (SCS) of 15 kHz, and other SCSs (e.g., 30 kHz, 60 kHz, 120 kHz, 240 kHz, etc.) can be defined relative to the basic SCS.

[0050] Figure 3 This is a diagram illustrating an example of NR frame format 300. The transmission timeline for each of the downlink and uplink can be divided into radio frame units. Each radio frame can have a predetermined duration (e.g., 10 ms) and can be divided into 10 subframes, each 1 ms long, indexed from 0 to 9. Each subframe can include a variable number of time slots (e.g., 1, 2, 4, 8, 16, ... time slots), depending on the SCS. Each time slot can include a variable number of symbol periods (e.g., 7, 12, or 14 symbols), depending on the SCS. A corresponding index can be assigned to the symbol periods in each time slot. The sub-time slot structure can refer to a duration shorter than the transmission time interval of the time slot (e.g., 2, 3, or 4 symbols). Each symbol in the time slot can be configured for the link direction of data transmission (e.g., DL, UL, or flexible), and the link direction of each subframe can be dynamically switched. The link direction may be based on the time slot format. Each time slot can include DL / UL data and DL / UL control information.

[0051] In NR, a Synchronization Signal Block (SSB) is transmitted. In some aspects, the SSB can be transmitted in a burst, where each SSB in the burst corresponds to a different beam direction for UE-side beam management (e.g., including beam selection and / or beam refinement). The SSB includes the PSS, SSS, and dual-symbol PBCH. The SSB can be transmitted at fixed time slot locations, such as... Figure 3The symbols 0-3 are shown in the diagram. The UE can use PSS and SSS for cell search and acquisition. PSS provides half-frame timing, and SS provides CP length and frame timing. PSS and SSS can provide cell identification. PBCH carries basic system information such as downlink system bandwidth, timing information within radio frames, SS burst set periodicity, and system frame number. SSBs can be organized into SS bursts to support beam scanning. Other system information, such as Residual Minimum System Information (RMSI), System Information Block (SIB), and Other System Information (OSI), can be transmitted in certain subframes on PDSCH. SSBs can be transmitted up to 64 times, for example, in up to 64 different beam directions for millimeter waves. Multiple transmissions of SSBs are called SS burst sets. SSBs in an SS burst set can be transmitted in the same frequency region, while SSBs in different SS burst sets can be transmitted in different frequency regions.

[0052] In some examples, communication between UE 120 and BS 110 is referred to as an access link. This access link can be provided via the Uu interface. Communication between devices can be referred to as a side link. Side link communication can be provided via the PC5 interface.

[0053] In some examples, two or more subordinate entities (e.g., UE 120) can communicate with each other using sidelink signaling. Practical applications of such sidelink communication can include public safety, proximity services, UE-to-network relay, vehicle-to-vehicle (V2V) communication, Internet of Things (IoE) communication, IoT communication, mission-critical networks, and / or various other suitable applications. Generally, sidelink signaling can refer to a signal transmitted from one subordinate entity (e.g., UE 120a) to another subordinate entity (e.g., another UE 120) without relaying the communication via a scheduling entity (e.g., UE 120 or BS 110), even if that scheduling entity may also be used for scheduling and / or control purposes. In some examples, licensed spectrum can be used to transmit sidelink signaling (unlike wireless LANs that typically use unlicensed spectrum). An example of sidelink communication is PC5, for example, used in V2V, LTE, and / or NR.

[0054] Various sidelink channels can be used for sidelink communication, including the Physical Sidelink Discovery Channel (PSDCH), Physical Sidelink Control Channel (PSCCH), Physical Sidelink Shared Channel (PSSCH), and Physical Sidelink Feedback Channel (PSFCH). The PSDCH can carry discovery expressions, enabling neighboring devices to discover each other. The PSCCH can carry control signaling, such as sidelink resource configuration and other parameters for data transmission, and the PSSCH can carry data transmission itself. The PSFCH can carry feedback, such as CSI related to sidelink channel quality.

[0055] Figure 4 and Figure 5 A schematic diagram of an exemplary vehicle-to-everything (V2X) system according to some aspects of this disclosure is shown. For example, Figure 4 and Figure 5 The vehicles shown can communicate via sidelink channels and can relay sidelink transmissions, as described herein.

[0056] Figure 4 and Figure 5 The V2X system provided in China offers two complementary transmission modes. The first transmission mode (also known as Mode 4) is... Figure 4 The example illustrates direct communication (e.g., also known as sidelink communication) between participants who are close to each other within a local area. The second transmission mode (also known as mode 3) is... Figure 5 The example shown involves network communication over a network, which can be implemented via a Uu interface (e.g., a wireless communication interface between a radio access network (RAN) and a UE).

[0057] Reference Figure 4 A V2X system 400 (e.g., including vehicle-to-vehicle (V2V) communication) is illustrated as two vehicles 402 and 404. A first transmission mode enables direct communication between different participants at a given geographical location. As shown, a vehicle can establish a wireless communication link 406 with a person (vehicle-to-person (V2P) link) via a PC5 interface (e.g., via a UE). Communication between vehicles 402 and 404 can also occur via PC5 interface 408. Similarly, communication can occur from vehicle 402 to other highway components (e.g., highway component 410), such as traffic signals or signs (vehicle-to-infrastructure (V2I)), for example, via PC5 interface 412. Figure 4Each communication link shown enables bidirectional communication between components, thus each component can be both a transmitter and a receiver of information. The V2X system 400 can be a self-managing system implemented without the assistance of a network entity. Self-managing systems can improve spectrum efficiency, reduce costs, and increase reliability because no network service interruption occurs during handover operations of mobile vehicles. The V2X system can be configured to operate in licensed or unlicensed spectrum, so any vehicle equipped with the system can access public frequencies and share information. This coordinated / public spectrum operation ensures operational security and reliability.

[0058] Figure 5 A V2X system 500 is illustrated that communicates between vehicles 552 and 554 via network entity 556. These network communications can be conducted via discrete nodes such as BSs (e.g., BS 110a) that can travel back and forth between vehicles 552 and 554 to send and receive information (e.g., relay information between the vehicles). Network communications via vehicle-to-network (V2N) links 558 and 510 can be used, such as network communications for long-distance communication between vehicles, for example, to inform of a traffic accident at a certain distance ahead on a road or highway. Wireless nodes can send other types of communications to vehicles, such as traffic flow conditions, road hazard warnings, environmental / weather reports, and service station availability. This data can be obtained from cloud-based shared services.

[0059] Roadside Units (RSUs) can be used. RSUs can be used for V2I communication. In some examples, an RSU can act as a forwarding node to extend the UE's coverage. In some examples, the RSU can be located in the same location as the BS, or it may be independent. RSUs can be classified in different ways. For example, RSUs can be divided into UE-type RSUs and micro NodeB-type RSUs. Micro NodeB-type RSUs have similar functionality to micro eNBs / gNBs. Micro NB-type RSUs can use the Uu interface. UE-type RSUs can be used to meet stringent Quality of Service (QoS) requirements by minimizing collisions and improving reliability. UE-type RSUs can use centralized resource allocation mechanisms to achieve efficient resource utilization. Critical information (e.g., traffic conditions, weather conditions, congestion statistics, sensor data, etc.) can be broadcast to UEs within the coverage area. Relay stations can rebroadcast critical information received from some UEs. UE-type RSUs can be reliable synchronization sources.

[0060] Sidelink communication can include cellular V2X (C-V2X) communication. C-V2X systems can operate in various modes. Figure 6This is an exemplary table 600 for PSCCH transmission parameters for various sidelink modes (e.g., as defined in Table 9.8-2 of TS 36.211).

[0061] An exemplary C-V2X mode (referred to as Mode 3) can be used when the UE is within the coverage area. In C-V2X Mode 3, the network can control the resource allocation for the sidelink UE. In another exemplary C-V2X mode (referred to as Mode 4), the sidelink UE can autonomously select resources (e.g., resource blocks (RBs)) for transmission. These resources can be semi-persistent scheduling (SPS) resources. In some examples, the sidelink UE can autonomously select resources based on an SPS algorithm. The SPS algorithm can be configured, hardcoded, or pre-configured on the UE. For example, the SPS algorithm can be based on the SPS algorithm defined in the 3GPP technical standard.

[0062] In some systems, UEs can use sensing mechanisms to select resources to transmit. By sensing available and unavailable resources, UEs can select and transmit vacant resources, thereby reducing or preventing collisions. This sensing may involve power estimation (e.g., Resource Signal Strength Indicator (RSSI) measurement). This power estimation can exclude subframes that were not measured (e.g., due to previous transmissions). Resource selection can exclude resources based on anticipated collisions with transmissions from other UEs. However, hidden UEs may be unaware of each other and therefore cannot exclude each other's resources. Therefore, transmissions from these UEs may collide on adjacent UEs.

[0063] In certain situations, a "hidden terminal" scenario may occur due to dynamic environmental changes. For example, when a sidelink UE selects resources for transmission (e.g., in mode 4), some other UEs (e.g., a vehicle) may be hidden (e.g., undetected) for example, when channel sensing is performed. Therefore, two (or more) UEs may (e.g., autonomously) select the same resources. A hidden terminal scenario (leading to data packet collisions) may also occur when UEs have overlapping coverage areas when allocating RBs for transmission.

[0064] Figure 7A An exemplary congestion scenario is illustrated. For example, UE A and UE C cannot sense each other's presence because these UEs are outside each other's coverage area. Figure 7A As shown, the physical distance d between UE A and UE C is at least r. A +r C , where r A It is the coverage radius of the UEA, and r CThis is the coverage radius of UE C. UE A is unaware of the existence of UE C (“hidden node”), and similarly, UE C is unaware of the existence of UE A. Since UE A and UE C are unaware of each other, these two UEs may allocate / select the same time-frequency resources (partial or all) (e.g., overlapping RBs) for transmission. In this case, UEs located in the common area of ​​UE A and UE C (A∩C) (such as...) Figure 7B The UE B shown is unable to use the allocated resources to decode data sent from UE A or UE C due to a data packet collision.

[0065] In congested scenarios, collisions and overlaps may occur. As used in this article, overlaps occur when two or more UEs transmit control channels (e.g., PSCCH) and data channels (e.g., PSSCH) on the same resource, and collisions occur when two or more UEs transmit control channels (e.g., PSCCH) on the same resource.

[0066] Figure 8A An exemplary conflict scenario is shown, and Figure 8B An exemplary overlapping scenario is shown. During a conflict, such as... Figure 8A As shown, PSCCH transmissions from UE1 and UE2 are transmitted on the same resource. During the overlap period, as... Figure 8B As shown, PSSCH and PSCCH transmissions from UE1 and UE2, respectively, use the same resources for transmission.

[0067] In cases of collisions and overlaps, if UE1 and UE2 send PSCCH and PSSCH transmissions, other UEs may not be able to detect the PSCCH (e.g., using sidelink control SCI). Although transmissions from both UEs may occur... Figure 8A and Figure 8B As shown in the figure, however, the system may involve sidelink transmissions from any number of UEs.

[0068] SCI can be carried on PSCCH and provides information about sidelink transmissions, such as scheduled PSSCH transmissions. Therefore, the UE can determine information about potential overlaps or conflicts from the information carried in the SCI. For SPS transmissions, an SPS transmission can last for one transmission period (e.g., 20, 50, 100, 200, ..., 1000 subframes). Therefore, the UE can determine information about potential overlaps or conflicts based on the periodicity of the SPS transmission. Hybrid Automatic Repeat Request (HARQ) transmissions may be mutually targeted. For example, redundant versions (e.g., RV0, RV2) may be associated (e.g., there may be 1, 2, ... 15 subframe gaps between redundant versions). Therefore, information about one RV can be determined from information about another RV. Figure 9 An exemplary SCI RV pair is shown.

[0069] In C-V2X Mode 4, vehicles autonomously select resources without the assistance of cellular infrastructure. Vehicles can use a sense-based SPS scheduling scheme. A vehicle can reserve selected resources for a random number of consecutive data packets. The number of packets can depend on the number of packets transmitted per second or be inversely proportional to the packet transmission interval. When a vehicle reserves a new resource, it may randomly select a reselection counter. After each transmission, the reselection counter is decremented by 1. When the reselection counter equals zero, the new resource is selected and reserved. New resources can be selected and reserved based on probability. Each vehicle can include its packet transmission interval and the value of its reselection counter in its SCI. Vehicles can use this information to estimate which resources are idle when autonomously reserving them, thus reducing packet collisions.

[0070] Vehicles can reserve resources from a selection window. The selection window can be a time window between the time the packet is generated and a defined maximum delay. Within the selection window, a vehicle can create a list of available resources it can reserve. This list can include all resources except those that meet specific conditions. For example, this list can exclude resources for which the vehicle has received a SCI from another vehicle in the last N (e.g., a pre-configured number) subframes, the SCI indicating that the other vehicle will utilize the resource in the selection window or any of its next reselection counter packets. This list can exclude resources for which the vehicle measures an average signal strength (e.g., Reference Received Power (RSRP) or Received Signal Strength Indicator (RSSI)) above a given threshold. After excluding resources to create the list, the vehicle can determine whether the list contains a threshold amount (e.g., 20%) of all resources initially identified in the selection window. If this list does not contain the threshold percentage of resources, the vehicle iterates through list creation until the threshold is reached. In each iteration, the vehicle increments the signal strength threshold (e.g., by 3 dB). The vehicle then randomly selects a candidate resource from the candidate resource list and reserves the randomly selected resource for the next reselection counter transmission.

[0071] The amount of resources used for transmission can be derived from any of the following: congestion level (N) limit The scheduler specifies the message size (e.g., Protocol Data Unit (PDU) packet size) and the allowed modulation and coding schemes (MCS) and physical resource blocks (PRBs). The scheduler (e.g., on a vehicle) can start with the default MCS and / or default subchannel values ​​and search for the correct "operating point" for the resources. For example, the scheduler can adjust the default MCS and / or subchannel values ​​to find a more robust MCS and a higher number of PRBs suitable for transmission, or a more efficient MCS and a lower number of PRBs.

[0072] In some cases, when the UE autonomously selects resources, it will exclude detected resources with signal strength exceeding a given threshold, and will not exclude resources (e.g., sub-channels) with detected signal strength (e.g., detected PSCCH transmissions), nor will it exclude undetected PSCCH transmissions (e.g., undetected PSCCHs indicated by lost HARQ RV0 or SPS and / or undetected PSCCHs without indication). Failure to exclude undetected PSCCH transmissions may lead to congestion (e.g., collisions and / or overlaps). Collisions and / or overlaps may also result in the loss of measurements helpful for link management (e.g., synchronization time offset and / or frequency offset). In some cases, due to PSCCH detection errors, the UE may falsely detect PSSCH transmissions because sidelink control information points to corresponding sidelink data transmissions.

[0073] Congestion can be detrimental to C-V2X communication and may lead to escalation of contention (e.g., Dedicated Short Range Communication (DSRC)). Congestion can affect packet error rate (PER) and / or message age (IA).

[0074] Therefore, what is needed are technologies and devices that enable UEs to make autonomous resource selections in order to reduce or avoid conflicts and / or overlaps.

[0075] Example of UE avoiding PSCCH resources during autonomous resource selection

[0076] Various aspects of this disclosure provide techniques for avoiding (e.g., preventing or reducing) the selection of Physical Sidelink Control Channel (PSCCH) resources during User Equipment (UE) autonomous sidelink resource selection. Avoiding the selection of PSCCH resources during UE autonomous sidelink resource selection can reduce conflicts (e.g., PSCCH on PSCCH allocation) and overlaps (e.g., Physical Sidelink Shared Channel (PSSCH) on PSCCH allocation).

[0077] Avoiding PSCCH resource selection may involve using the flagged PSCCHs known from the Side Link Control Information (SCI) of the detected redundant versions (RVs) to determine which PSCCH resources to avoid. For example, the UE may receive the initial SCI transmission (e.g., RV0). The initial SCI may point to an SCI retransmission (e.g., RV2). The UE may also determine the SCI based on the semi-persistent scheduling (SPS) periodicity.

[0078] Figure 10This is a decision tree diagram illustrating an autonomous resource selection process according to some aspects of this disclosure. The autonomous resource selection process 1000 can be performed, for example, by a UE (e.g., UE 120a in wireless communication network 100). The autonomous resource selection process 1000 can be implemented in one or more processors (e.g., Figure 2 Software components that execute and run on the controller / processor 280.

[0079] In some examples, the UE follows the above-described Cellular Vehicle-to-Everything (C-V2X) Mode 4 autonomous reselection. The autonomous resource selection process 1000 can begin at 1005, that is, starting from all available transmission resources within the window (e.g., a first set of resources including all available transmission resources in the window).

[0080] As shown in the figure, when reducing collisions, the UE excludes resources (e.g., PSCCH resources used for SCI transmission) whose signal strength is higher or lower than the signal strength threshold of the autonomous sidelink resource selection process. In 1010, the UE excludes resources exceeding the signal strength threshold to form a second set of unexcluded resources. For example, the UE can set a signal strength threshold, such as a Reference Signal Received Power (RSRP) threshold, and compare the signal strength of a resource with the signal strength threshold. Based on the comparison of the resource's signal strength with the signal strength threshold, if the signal strength of a resource is higher than the signal strength threshold, the UE may exclude that resource.

[0081] The UE can perform exclusion until a threshold number of PSCCHs (e.g., at least 20%) still remain. In step 1015, the UE determines whether the amount of unexcluded resources (e.g., the amount of resources in the second resource set) is greater than a threshold percentage (e.g., 20%) of the total available transmission resources in the window (e.g., the first resource set). If the amount of unexcluded resources is less than a threshold percentage of all available transmission resources in the window, then in step 1025, the UE increases the signal strength threshold so that fewer resources are excluded and the amount of non-excluded resources is more likely to be above the threshold percentage. Accordingly, the UE repeats the steps of excluding resources above the signal strength threshold (in step 1010) and determining whether the amount of unexcluded resources is greater than the threshold percentage (in step 1015). As illustrated, the UE can perform resource exclusion in autonomous resource selection by adjusting (e.g., increasing) the signal strength threshold and excluding both PSCCHs and corresponding PSSCH resources (e.g., PSSCH resources indicated by SCI in the PSCCH) until the amount of resources in the list (e.g., unexcluded resources) is equal to or greater than a threshold percentage (e.g., 20%) of the initially identified resources in the transmission window.

[0082] If the amount of unexcluded resources (e.g., the amount of resources in the second resource set) is greater than a threshold percentage of the total available resources in the window (i.e., the first resource set), then in 1020, the UE can set a lower signal strength threshold. In some aspects, if the UE raises the threshold during resource exclusion, then in 1025, the UE can reset the signal strength threshold to its initial or default value.

[0083] After setting a lower signal strength threshold, in 1030, the UE only excludes PSCCH resources that are above the signal strength threshold. This exclusion forms a third resource set, which includes resources that were not excluded in the second resource set. In some aspects, the UE only excludes PSCCH resources without excluding the corresponding PSSCH resources. Therefore, the UE can exclude more PSCCHs and reduce the likelihood of collisions. The exclusion process may include non-physical parameters, such as priority or the corresponding RV of a missed initial transmission (e.g., RV2 of missed RV0).

[0084] In step 1035, the UE determines whether the amount of unexcluded resources after the most recent round of exclusion (i.e., the amount of unexcluded resources in the third resource set) is greater than a threshold percentage (e.g., 20%) of the total available transmission resources in the window. If the remaining resources are less than the percentage of resources, then in step 1045, the UE increases the signal strength threshold by a predefined amount (e.g., increases it by 3 dB) and repeats the exclusion process (in step 1030) using the increased signal strength threshold, and re-determines (in step 1035) whether the amount of unexcluded resources after the exclusion is still less than the threshold percentage. The UE iterates this process until the amount of unexcluded resources reaches the threshold percentage.

[0085] If the UE determines that the amount of unexcluded resources after the most recent round of exclusion (i.e., the amount of unexcluded resources in the third resource set) is greater than a threshold percentage (e.g., 20%) of all available transmission resources in the window, then in step 1040, the UE randomly selects resources for PSCCH transmission from the unexcluded PSCCH resources (i.e., the third resource set). In some aspects, the UE may allocate resources using a default number of resources (e.g., sub-channels) and / or a default modulation and coding scheme (MCS) for PSCCH transmission.

[0086] To reduce overlap, the UE can adjust the default MCS and / or the default resource quantity to avoid selecting resources with "tagged" PSCCH transmissions. By adjusting the default MCS and the default resource quantity, the UE can customize random resource selection so that when the UE randomly selects resources, the resources selected by the UE avoid overlap with shared channel transmissions.

[0087] When adjusting the default MCS and / or the default number of resources, the UE can increase the default MCS and correspondingly decrease the default number of sub-channels, or decrease the default MCS and correspondingly increase the default number of sub-channels. In some examples, the UE can search for a more robust MCS with an increased number of sub-channels by adding sub-channels that do not include tagged PSCCHs. Adding a sub-channel may involve decreasing the PSCCH index or adding another PSCCH sub-channel. In some aspects, the UE can search for less robust MCSs with fewer sub-channels. In these aspects, the UE can delete sub-channels that include tagged PSCCHs, which may involve increasing the PSCCH index or decreasing the last PSCCH sub-channel.

[0088] Figure 11 This is a flowchart illustrating an exemplary wireless communication operation 1100 according to certain aspects of this disclosure. Operation 1100 can be performed, for example, by a UE (e.g., UE 120a in wireless communication network 100). Operation 1100 can be implemented in one or more processors (e.g., Figure 2 The software components that execute and run on the controller / processor 280. Furthermore, the signal transmission and reception performed by the UE in operation 1100 can, for example, be via one or more antennas (e.g., Figure 2 This can be achieved through an antenna 252. In some aspects, the signal transmission and / or reception performed by the UE can be implemented through a bus interface in one or more processors (e.g., controller / processor 280) that acquires and / or outputs signals.

[0089] Operation 1100 may begin at 1105, in which autonomous sidelink resource selection is performed. In this autonomous sidelink resource selection, at 1106, the UE excludes one or more resources associated with transmissions whose signal strength is higher than a first signal strength threshold from a first resource set to form a second resource set. At 1107, the UE determines that the amount of resources in the second resource set is equal to or higher than a threshold percentage of the amount of resources in the first resource set. At 1108, without excluding one or more resources associated with one or more PSSCHs associated with the one or more PSCCHs, the UE excludes one or more resources associated with the one or more PSCCHs from the second resource set to form a third resource set. At 1109, the UE randomly selects one or more resources from the third resource set for PSCCH transmission.

[0090] In some aspects, excluding one or more resources associated with one or more PSCCHs from the second resource set includes excluding one or more resources associated with one or more PSCCHs having the highest signal strength. In some aspects, excluding one or more resources associated with one or more PSCCHs from the second resource set includes: excluding one or more resources associated with one or more PSCCHs whose signal strength is higher than a second signal strength threshold from the second resource set to form a third resource set, and determining whether the amount of resources in the third resource set is equal to or higher than a threshold percentage of the amount of resources in the first resource set. In other aspects, when the amount of resources in the third resource set is lower than a threshold percentage of the amount of resources in the first resource set, the following steps are performed iteratively until the resources in the third resource set are equal to or higher than a threshold percentage of the amount of resources in the first resource set: the UE may raise the second signal strength threshold to the third signal strength threshold. In these other aspects, the UE may further exclude one or more resources associated with one or more PSCCHs whose signal strength is higher than a third signal strength threshold from the second resource set to form a third resource set; and redetermine whether the amount of resources in the third resource set is equal to or higher than a threshold percentage of the amount of resources in the first resource set.

[0091] In some respects, the resources for PSCCH transmission are randomly selected from the third resource set based on a threshold percentage that determines the amount of resources in the third resource set is equal to or higher than the amount of resources in the first resource set.

[0092] In 1110, the UE uses one or more randomly selected resources to transmit the PSCCH transmission.

[0093] In some aspects, in 1115, the UE can identify one or more PSCCHs as one or more PSCCH retransmissions based on one or more Side Link Control Information (SCIs) in one or more initial PSCCH transmissions. The UE can identify one or more PSCCHs based on Semi-Persistent Scheduling (SPS). The autonomous sidelink resource selection can include autonomous resource selection in CV2X Mode 4. In some aspects, the first resource set can include resources within a selected transmission window. In some aspects, excluding resources associated with transmissions whose signal strength is higher than a first signal strength threshold from the first resource set to form a second resource set also includes excluding resources indicated in the SCIs within a previous number of subframes. In some aspects, the threshold percentage may be twenty percent.

[0094] In some aspects, the UE can adjust the default modulation and coding scheme (MCS) and default resource quantity used for message transmission to avoid selecting resources with PSCCH transmission, and when the UE randomly selects resources for PSCCH transmission from a third resource set, the UE randomly selects the adjusted resource quantity. In other aspects, when the UE adjusts the default MCS and default resource quantity used for message transmission to avoid selecting resources with PSCCH transmission, the UE increases the default MCS and decreases the default sub-channel quantity so that it can avoid sub-channels with PSCCH transmission when selecting sub-channels from a second resource set. In some aspects, when the UE adjusts the default MCS and default resource quantity used for message transmission to avoid selecting resources with PSCCH transmission, the UE decreases the default MCS and increases the default sub-channel quantity so that it can avoid unexcluded sub-channels with PSCCH transmission and select sub-channels with unexcluded resources from the second resource set.

[0095] Figure 12 This is a flowchart illustrating an exemplary signaling 1100 between UE1 and UE2 according to some aspects of this disclosure. In 1202, UE1 can receive an RV0 PSCCH transmission from UE2, which can provide an SCI and information about the corresponding PSCCH. In 1204, the UE can perform autonomous sidelink resource selection, whereby the UE avoids selecting a PSCCH resource. Once the UE autonomously selects its resource, in 1206, UE1 can use the autonomously selected resource to send a PSCCH transmission.

[0096] In some aspects, when the UE excludes resources in 1204, the UE excludes transmission-related resources based on a specific signal strength threshold (e.g., an RSRP threshold). For example, the UE can exclude resources associated with transmissions whose signal strength is higher than a first signal strength threshold from the total resources to form a first set of unexcluded resources. Subsequently, the UE can perform additional exclusions based on a threshold percentage of the total resources (e.g., 20% of the total resources). For example, the UE can exclude resources associated with one or more control channels and include the corresponding shared channels in the resource set. By excluding resources associated with control channels in 1204, the UE reduces the likelihood of conflicts when randomly selecting resources for PSCCH transmissions for the UE.

[0097] When excluding resources associated with a control channel in step 1204, the UE can exclude control channels with the highest signal strength or above a second signal strength threshold. After each exclusion, if the unexcluded resources fall below a threshold percentage (e.g., 20% of total resources), the UE can increase the second signal threshold used to exclude control channels so that the unexcluded resources are equal to or above the threshold percentage. Accordingly, some resources that may have been excluded before the second signal threshold was increased will be re-included in the unexcluded resources randomly selected by the UE from among them.

[0098] Figure 13 A communication device 1300 is shown that may include various components (e.g., components corresponding to component plus function) configured to perform operations of the techniques disclosed herein, such as... Figure 11 The operation is illustrated. Communication device 1300 includes a processing system 1302 coupled to transceiver 1308 (e.g., transmitter and / or receiver). Transceiver 1308 is configured to transmit and receive signals to and from communication device 1300 via antenna 1310, such as the various signals described herein. Processing system 1302 may be configured to perform processing functions of communication device 1300, including processing signals received and / or transmitted by communication device 1300.

[0099] Processing system 1302 includes processor 1304 coupled to computer-readable medium / memory 1312 via bus 1306. In some aspects, computer-readable medium / memory 1312 is configured to store instructions (e.g., computer-executable code) that, when executed by processor 1304, cause processor 1304 to perform... Figure 11The operations shown, or other operations used to perform the various techniques discussed herein for avoiding the selection of PSCCH resources during UE autonomous resource selection. In some aspects, computer-readable medium / memory 1312 stores code 1314 for performing autonomous sidelink resource selection; and code 1316 for transmitting PSCCH transmissions using one or more randomly selected resources. In some aspects, computer-readable medium / memory 1312 stores code 1320 for identifying one or more PSCCHs as one or more PSCCH retransmissions based on one or more SCIs in one or more initial PSCCH transmissions. In some aspects, processor 1304 has circuitry configured to implement the code stored in computer-readable medium / memory 1312. The processor 1304 includes circuitry 1324 for performing autonomous sidelink resource selection; and circuitry 1326 for transmitting PSCCH transmissions using one or more randomly selected resources. In some aspects, the processor 1304 includes circuitry 1330 for identifying one or more PSCCHs as one or more PSCCH retransmissions based on one or more SCIs in one or more initial PSCCH transmissions.

[0100] For example, the component for transmitting (or the component for output transmission) may include Figure 2 The transmitter unit 254 and / or antenna 252 in the UE 120a shown, and / or Figure 13 The circuit 1326 in the communication device 1300 shown. The component for receiving (or for acquiring) may include... Figure 2 The receiver and / or antenna 252 of the UE 120a shown. Components for communication may include a transmitter, a receiver, or both. Components for generation, execution, determination, operation, and coordination may include a processing system, which may include one or more processors, such as... Figure 2 The UE 120a shown includes a receive processor 258, a transmit processor 264, a TX MIMO processor 266, and / or a controller / processor 280, and / or Figure 13 The processing system 1302 of the communication device 1300 shown.

[0101] Exemplary aspects

[0102] Examples of implementation plans are described in the following numbered items:

[0103] Aspect 1. A method for wireless communication, the method comprising: performing autonomous sidelink resource selection, the autonomous sidelink selection comprising: excluding one or more resources associated with transmissions having a signal strength higher than a first signal strength threshold from a first resource set to form a second resource set; determining that the amount of resources in the second resource set is equal to or higher than a threshold percentage of the amount of resources in the first resource set; excluding one or more resources associated with one or more physical sidelink shared channels (PSSCHs) associated with one or more sidelink control channels (PSCCHs) from the second resource set to form a third resource set without excluding one or more resources associated with one or more physical sidelink shared channels (PSSCHs) associated with one or more sidelink control channels (PSCCHs) to form a third resource set; randomly selecting one or more resources from the third resource set for PSCCH transmission; and using the randomly selected one or more resources to transmit the PSCCH transmission.

[0104] Aspect 2. The method according to aspect 1, wherein excluding one or more resources associated with the one or more PSCCHs from the second resource set comprises: excluding one or more resources associated with the one or more PSCCHs having the highest signal strength.

[0105] Aspect 3. The method according to any one of Aspect 1 and Aspect 2, wherein excluding one or more resources associated with the one or more PSCCHs from the second resource set comprises: excluding one or more resources associated with one or more PSCCHs whose signal strength is higher than a second signal strength threshold from the second resource set to form the third resource set; and determining whether the amount of resources in the third resource set is equal to or higher than a threshold percentage of the amount of resources in the first resource set.

[0106] Aspect 4. The method according to Aspect 3, further comprising: when the amount of resources in the third resource set is less than a threshold percentage of the amount of resources in the first resource set, iteratively performing the following steps until the amount of resources in the third resource set is equal to or greater than a threshold percentage of the amount of resources in the first resource set: raising the second signal strength threshold to a third signal strength threshold; excluding one or more resources associated with one or more PSCCHs with signal strengths greater than the third signal strength threshold from the second resource set to form the third resource set; and re-determining whether the amount of resources in the third resource set is equal to or greater than a threshold percentage of the amount of resources in the first resource set.

[0107] Aspect 5. The method according to any one of Aspects 3 and 4, wherein the resource randomly selected from the third resource set for the PSCCH transmission is based on a threshold percentage that determines that the amount of the resource in the third resource set is equal to or greater than the amount of the resource in the first resource set.

[0108] Aspect 6. The method according to any one of Aspects 1 to 5, further comprising: identifying the one or more PSCCHs as one or more PSCCH retransmissions based on one or more side link control information (SCI) in one or more initial PSCCH transmissions.

[0109] Aspect 7. The method according to any one of Aspects 1 to 6, further comprising: identifying the one or more PSCCHs based on semi-persistent scheduling (SPS).

[0110] Aspect 8. The method according to any one of Aspects 1 to 7, wherein the autonomous sidelink resource selection includes autonomous resource selection in Cellular Vehicle-to-Everything (CV2x) Mode 4.

[0111] Aspect 9. The method according to any one of Aspects 1 to 8, wherein the first resource set includes resources within a selected transmission window.

[0112] Aspect 10. The method according to any one of Aspects 1 to 9, wherein excluding resources associated with transmissions whose signal strength is higher than the first signal strength threshold from the first resource set to form a second resource set further comprises: excluding resources indicated in side link control information (SCI) within a previous number of subframes.

[0113] Aspect 11. The method according to any one of Aspects 1 to 10, wherein the threshold percentage includes twenty percent.

[0114] Aspect 12. The method according to any one of Aspects 1 to 11, further comprising: adjusting the default modulation and coding scheme (MCS) and default resource quantity for transmitting messages to avoid selecting resources for transmission with Physical Side Link Control Channel (PSCCH), wherein randomly selecting resources for PSCCH transmission from the third resource set includes randomly selecting the adjusted resource quantity.

[0115] Aspect 13. The method according to aspect 12, wherein adjusting the default MCS and the default number of resources used for sending messages to avoid selecting resources with PSCCH transmission includes: increasing the default MCS and decreasing the default number of sub-channels so that sub-channels with PSCCH transmission can be avoided when selecting sub-channels from the second resource set.

[0116] Aspect 14. The method according to any one of Aspects 12 to 13, wherein adjusting the default MCS and the default number of resources used for sending messages to avoid selecting resources with PSCCH transmission includes: reducing the default MCS and increasing the default number of sub-channels so that unexcluded sub-channels for PSCCH transmission can be avoided when selecting sub-channels from the second resource set.

[0117] Aspect 15. An apparatus comprising components for performing the method according to any one of aspects 1 to 14.

[0118] Aspect 16. An apparatus comprising at least one processor and a memory coupled to said at least one processor, said memory including code executable by said at least one processor to cause the apparatus to perform the method of any one of Aspects 1 to 14.

[0119] Aspect 17. A computer-readable medium having computer-executable code stored thereon, the computer-executable code, when executed by at least one processor, causing a device to perform the method described in any one of Aspects 1 to 14.

[0120] The techniques described herein can be used in various wireless communication technologies, such as NR (e.g., 5G NR), 3GPP Long Term Evolution (LTE), LTE-A Advanced (LTE-A), Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Single Carrier Frequency Division Multiple Access (SC-FDMA), Time Division Synchronous Code Division Multiple Access (TD-SCDMA), and other networks. The terms "network" and "system" are generally used interchangeably. CDMA networks can implement radio technologies such as Universal Terrestrial Radio Access (UTRA), CDMA2000, etc. UTRA includes Wideband CDMA (WCDMA) and other variations of CDMA. CDMA2000 encompasses the IS-2000, IS-95, and IS-856 standards. TDMA networks can implement radio technologies such as Global System for Mobile Communications (GSM). OFDMA networks can implement radio technologies such as NR (e.g., 5G RA), evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDMA, etc. UTRA and E-UTRA are part of the Universal Mobile Telecommunications System (UMTS). LTE and LTE-A are UMTS versions using E-UTRA. Documents published by an organization called the 3rd Generation Partnership Project (3GPP) describe UTRA, E-UTRA, UMTS, LTE, LTE-A, and GSM. Documents published by an organization called the 3rd Generation Partnership Project 2 (3GPP2) describe CDMA2000 and UMB. NR is an emerging wireless communication technology under development.

[0121] In 3GPP, the term "cell" can refer to the coverage area of ​​a Node B (NB) and / or the NB subsystem serving that coverage area, depending on the context in which the term is used. In NR systems, the terms "cell" and BS, Next Generation Node B (gNB or gNodeB), Access Point (AP), Distributed Unit (DU), Carrier, or Transmit / Receive Point (TRP) are used interchangeably. A BS can provide communication coverage for macrocells, picocells, femtocells, and / or other types of cells. A macrocell can cover a relatively large geographic area (e.g., a radius of several kilometers) and can allow unrestricted access for UEs with service subscriptions. A picocell can cover a relatively small geographic area and can allow unrestricted access for UEs with service subscriptions. A femtocell can cover a relatively small geographic area (e.g., a home) and can allow restricted access for UEs associated with the femtocell (e.g., UEs in a Closed Subscriber Group (CSG), UEs of home users, etc.). A BS used for a macrocell can be called a macro BS. A BS used for a picocell can be called a pico BS. A BS used for a femtocell can be called a femto BS or a home BS.

[0122] A UE can also be referred to as a mobile station, terminal, access terminal, subscriber unit, site, customer premises equipment (CPE), cellular phone, smartphone, personal digital assistant (PDA), wireless modem, wireless communication device, handheld device, laptop computer, cordless phone, wireless local loop (WLL) station, tablet computer, camera, gaming device, netbook, smartbook, ultrabook, appliance, medical device or medical equipment, biometric sensor / device, wearable devices such as smartwatches, smart clothing, smart glasses, smart wristbands, smart jewelry (e.g., smart rings, smart bracelets, etc.), entertainment devices (e.g., music devices, video devices, satellite radios, etc.), vehicle components or sensors, smart meters / sensors, industrial manufacturing equipment, GPS devices, or any other suitable device configured to communicate via wireless or wired media. Some UEs can be considered as machine-type communication (MTC) devices or evolved MTC (eMTC) devices. MTC and eMTC UEs include, for example, robots, drones, remote devices, sensors, meters, monitors, location tags, etc., that can communicate with a BS, another device (e.g., a remote device), or other entities. For example, wireless nodes can provide connectivity to or to a network (e.g., a wide area network such as the Internet or cellular networks) via wired or wireless communication links. Some UEs can be considered Internet of Things (IoT) devices, which can be narrowband Internet of Things (NB-IoT) devices.

[0123] In some examples, air interface access can be scheduled. A scheduling entity (e.g., a BS) allocates resources for communication between some or all devices and equipment within its service area or cell. The scheduling entity can be responsible for scheduling, allocating, reconfiguring, and releasing resources for one or more subordinate entities. That is, for scheduled communication, the subordinate entity utilizes the resources allocated by the scheduled entity. A base station is not the only entity that can act as a scheduling entity. In some examples, a UE can act as a scheduling entity and can schedule resources for one or more subordinate entities (e.g., one or more other UEs), which can then utilize the resources scheduled by the UE for wireless communication. In some examples, a UE can act as a scheduling entity in peer-to-peer (P2P) networks and / or mesh networks. In mesh network examples, in addition to communicating with a scheduling entity, UEs can also communicate directly with each other.

[0124] The methods disclosed herein include one or more steps or actions for carrying out these methods. The method steps and / or actions may be interchanged with each other without departing from the scope of the claims. In other words, unless a specific order of steps or actions is specified, the order and / or use of specific steps and / or actions may be modified without departing from the scope of the claims.

[0125] As used herein, the phrase “at least one of a series of items” refers to any combination of those items, including a single member. For example, “at least one of a, b, or c” is intended to cover a, b, c, ab, ac, bc, and abc, as well as any combination of multiple such elements (e.g., aa, aaa, aab, aac, abb, acc, bb, bbb, bbb, cc, and ccc, or any other order of a, b, and c).

[0126] As used herein, the term "determine" encompasses a variety of actions. For example, "determine" can include calculation, inference, processing, derivation, investigation, searching (e.g., looking in a table, database, or other data structure), confirmation, etc. Furthermore, "determine" can include receiving (e.g., receiving information), accessing (e.g., accessing data in memory), etc. Additionally, "determine" can include resolving, selecting, choosing, establishing, etc.

[0127] The foregoing description is intended to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to a person skilled in the art, and the general principles defined herein can be applied to other aspects. Therefore, the claims are not intended to be limited to the aspects shown herein, but are to be consistent with the full scope of the language of the claims, wherein, unless specifically stated otherwise, an element referred to in the singular is not intended to mean "one and only one," but rather "one or more." Unless expressly stated otherwise, the term "some" means one or more. All structural and functional equivalents of the elements of the various aspects described throughout this disclosure that are currently known or will become known in the future to a person skilled in the art are expressly incorporated herein by reference and are intended to be covered within the scope of the claims. Furthermore, nothing disclosed herein is intended for public dissemination, whether or not such disclosure is expressly stated in the claims. Unless explicitly quoted using the phrase “component for…” or, in the case of a method claim, explicitly quoted using the phrase “step for…”, no element of the claim shall be construed under 35 U.S.C. § 112(f) (35 U.S.SC § 112(f)).

[0128] The various operations described above can be performed by any suitable component capable of performing the corresponding function. Such components may include a variety of hardware and / or software components and / or modules, including but not limited to circuits, digital signal processors (DSPs), application-specific integrated circuits (ASICs), or processors (e.g., general-purpose or specifically programmed processors). Generally, in the cases of the operations illustrated in the figures, these operations may have equivalent components with similar numbering plus functional components.

[0129] The various illustrative logic blocks, modules, and circuits described herein can be implemented or executed using general-purpose processors, DSPs, ASICs, field-programmable gate arrays (FPGAs) or other programmable logic devices (PLDs), discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. The general-purpose processor may be a microprocessor, but alternatively, the processor may be any commercially available processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors combined with a DSP core, or any other such configuration.

[0130] If implemented in hardware, an exemplary hardware configuration may include a processing system in a wireless node. The processing system can be implemented using a bus architecture. Depending on the specific application and overall design constraints of the processing system, the bus may include any number of interconnect buses and bridges. The bus can link various circuits together, including processors, machine-readable media, and bus interfaces. The bus interface can be used to connect network adapters, etc., to the processing system via the bus, etc. The network adapter can be used to implement signal processing functions at the PHY layer. In the user terminal (see...), Figure 1 In this case, the user interface (e.g., keyboard, display, mouse, joystick, etc.) can also be connected to the bus. The bus can also link various other circuits known in the art, such as timing sources, peripheral devices, voltage regulators, power management circuits, etc., and therefore will not be described further. The processor can be implemented using one or more general-purpose and / or special-purpose processors. Examples include microprocessors, microcontrollers, DSP processors, and other circuits capable of executing software. Those skilled in the art will recognize how best to implement the functions described for the processing system, depending on the specific application and the overall design constraints imposed on the system as a whole.

[0131] If implemented in software form, these functions can be stored or transmitted as one or more instructions or code on a computer-readable medium. Software should be interpreted broadly as instructions, data, or any combination thereof, whether referred to as software, firmware, middleware, microcode, hardware description language, or others. Computer-readable media includes both computer storage media and communication media, including any medium that facilitates the transfer of a computer program from one place to another. The processor may be responsible for managing the bus and general processing, including executing software modules stored on the machine-readable storage medium. The computer-readable storage medium may be coupled to the processor, allowing the processor to read information from and write information to the storage medium. Alternatively, the storage medium may be integrated into the processor. As an example, the machine-readable medium may include a transmission line, a data-modulated carrier wave, and / or a computer-readable storage medium storing instructions separate from the wireless node, all of which can be accessed by the processor via a bus interface. Alternatively or additionally, the machine-readable medium or any portion thereof may be integrated into the processor, for example, in cases where it may have a cache and / or a general-purpose register file. Examples of machine-readable storage media may include, for example, RAM (random access memory), flash memory, ROM (read-only memory), PROM (programmable read-only memory), EPROM (erasable programmable read-only memory), EEPROM (electrically erasable programmable read-only memory), registers, disks, optical disks, hard disks, or any other suitable storage media, or any combination thereof. Machine-readable media may be implemented in computer program products.

[0132] Software modules may include a single instruction or multiple instructions and may be distributed across several different code segments, different programs, and multiple storage media. Computer-readable media may include multiple software modules. The software module includes instructions that, when executed by a device such as a processor, enable the processing system to perform various functions. Software modules may include sending modules and receiving modules. Each software module may reside in a single storage device or be distributed across multiple storage devices. For example, a software module may be loaded from a hard disk drive into RAM when a triggering event occurs. During the execution of a software module, the processor may load some instructions into a cache to improve access speed. One or more cache lines may then be loaded into a general-purpose register file for processor execution. When the functionality of a software module is referred to below, it should be understood that this functionality is implemented by the processor when executing instructions from that software module.

[0133] Furthermore, any connection is appropriately referred to as computer-readable medium. For example, if software is being transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared (IR), radio, and microwave, the definition of medium includes coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave. Disks and optical discs as used herein include compact optical discs (CDs), laser discs, optical discs, digital versatile discs (DVDs), floppy disks, and... Optical discs, where magnetic disks typically reproduce data magnetically, use lasers to optically reproduce data. Therefore, in some aspects, computer-readable media can include non-transitory computer-readable media (e.g., tangible media). Furthermore, in other aspects, computer-readable media can include transient computer-readable media (e.g., signals). Combinations of the above should also be included within the scope of computer-readable media.

[0134] Therefore, certain aspects may include computer program products for performing the operations presented herein. For example, such computer program products may include a computer-readable medium having instructions stored thereon (and / or encoded thereon) that are executable by one or more processors to perform the operations described herein, such as those for performing the operations described herein. Figure 11 The instructions for the operation shown.

[0135] Furthermore, it should be understood that modules and / or other suitable components for performing the methods and techniques described herein may be downloaded and / or otherwise obtained by applicable user terminals and / or base stations. For example, such devices may be coupled to a server to facilitate the transfer of components for performing the methods described herein. Alternatively, the various methods described herein may be provided via storage components (e.g., RAM, ROM, physical storage media such as CDs or floppy disks), enabling user terminals and / or base stations to obtain the various methods when the storage components are coupled or provided to the devices. Additionally, any other suitable techniques for providing the methods and techniques described herein to the devices may be used.

[0136] It should be understood that the claims are not limited to the precise configuration and components described above. Various modifications, alterations, and variations may be made to the arrangement, operation, and details of the above-described methods and apparatus without departing from the scope of the claims.

Claims

1. An apparatus for wireless communication, comprising: At least one processor; as well as A memory coupled to the at least one processor, the memory including code executable by the at least one processor to cause the device to perform the following operations: Perform autonomous sidelink resource selection, including: One or more resources associated with transmissions whose signal strength is higher than a first signal strength threshold are excluded from the first resource set to form a second resource set; Determine the percentage by which the amount of resources in the second resource set is equal to or higher than the amount of resources in the first resource set; Without excluding one or more resources associated with one or more Physical Side Link Shared Channels (PSSCHs) associated with one or more Physical Side Link Control Channels (PSCCHs), one or more resources associated with said one or more PSCCHs are excluded from the second resource set to form a third resource set; and One or more resources are randomly selected from the third resource set for PSCCH transmission; and The PSCCH transmission is sent using one or more randomly selected resources.

2. The apparatus of claim 1, wherein the code, which can be executed by the at least one processor to cause the apparatus to exclude the one or more resources associated with the one or more PSCCHs from the second resource set, comprises: Code that can be executed by the at least one processor to cause the device to exclude one or more resources associated with one or more PSCCHs having the highest signal strength.

3. The apparatus of claim 1, wherein the code executable by the at least one processor to cause the apparatus to exclude the one or more resources associated with the one or more PSCCHs from the second resource set includes code executable by the at least one processor to cause the apparatus to perform the following operations: Exclude one or more resources associated with one or more PSCCHs whose signal strength is higher than a second signal strength threshold from the second resource set to form a third resource set; and Determine whether the amount of resources in the third resource set is equal to or higher than the threshold percentage of the amount of resources in the first resource set.

4. The apparatus of claim 3, wherein the memory further comprises code executable by the at least one processor to cause the apparatus to perform the following operations: When the amount of resources in the third resource set is lower than the threshold percentage of the amount of resources in the first resource set, the following steps are performed iteratively until the amount of resources in the third resource set is equal to or higher than the threshold percentage of the amount of resources in the first resource set: Raise the second signal strength threshold to the third signal strength threshold; Exclude one or more resources from the second resource set that are associated with one or more PSCCHs whose signal strength is higher than the third signal strength threshold to form the third resource set; and Re-determine whether the amount of resources in the third resource set is equal to or higher than the threshold percentage of the amount of resources in the first resource set.

5. The apparatus of claim 3, wherein the code executable by the at least one processor to cause the apparatus to randomly select the resources for the PSCCH transmission from the third resource set is based on code executable by the at least one processor to cause the apparatus to redetermine the amount of resources in the third resource set to be equal to or higher than the threshold percentage of the amount of resources in the first resource set.

6. The apparatus of claim 1, wherein the memory further comprises code executable by the at least one processor to cause the apparatus to perform the following operations: Based on one or more side link control information (SCI) in one or more initial PSCCH transmissions, the one or more PSCCHs are identified as one or more PSCCH retransmissions.

7. The apparatus of claim 1, wherein the memory further comprises code executable by the at least one processor to cause the apparatus to perform the following operations: The one or more PSCCHs are identified based on semi-persistent scheduling (SPS).

8. The apparatus of claim 1, wherein the autonomous sidelink resource selection includes autonomous resource selection in cellular vehicle-to-everything (CV2x) mode 4.

9. The apparatus of claim 1, wherein the first resource set comprises resources within a selected transmission window.

10. The apparatus of claim 1, wherein the code executable by the at least one processor to cause the apparatus to exclude resources associated with transmissions having signal strengths higher than the first signal strength threshold from the first resource set to form a second resource set further comprises code executable by the at least one processor to cause the apparatus to perform the following operations: Exclude resources indicated in the Side Link Control Information (SCI) within the previous number of subframes.

11. The apparatus of claim 1, wherein the threshold percentage includes twenty percent.

12. The apparatus of claim 1, wherein the memory further comprises code executable by the at least one processor to cause the apparatus to perform the following operations: Adjust the default modulation and coding scheme (MCS) and default resource number used for message transmission to avoid selecting resources with Physical Side Link Control Channel (PSCCH) transmission, where The code that can be executed by at least one processor to enable the device to randomly select resources from the third resource set for the PSCCH transmission includes code that can be executed by the at least one processor to enable the device to randomly select an adjusted number of resources.

13. The apparatus of claim 12, wherein the code executable by the at least one processor to cause the apparatus to adjust the default MCS and the default number of resources for sending messages to avoid selecting resources with PSCCH transmission includes code executable by the at least one processor to cause the apparatus to perform the following operations: Increase the default MCS and decrease the default number of sub-channels so that when selecting a sub-channel from the second resource set, the selection of a sub-channel with PSCCH transmission is avoided.

14. The apparatus of claim 12, wherein the code executable by the at least one processor to cause the apparatus to adjust the default MCS and the default number of resources used for sending messages to avoid selecting resources with PSCCH transmission includes code executable by the at least one processor to cause the apparatus to perform the following operations: Reduce the default MCS and increase the default number of sub-channels so that when selecting sub-channels from the second resource set, unexcluded sub-channels with PSCCH transmissions are avoided.

15. A method for wireless communication, comprising: Perform autonomous sidelink resource selection, which includes: One or more resources associated with transmissions whose signal strength is higher than a first signal strength threshold are excluded from the first resource set to form a second resource set; Determine the percentage by which the amount of resources in the second resource set is equal to or higher than the amount of resources in the first resource set; Without excluding one or more resources associated with one or more Physical Side Link Shared Channels (PSSCHs) associated with one or more Physical Side Link Control Channels (PSCCHs), one or more resources associated with said one or more PSCCHs are excluded from the second resource set to form a third resource set; and One or more resources are randomly selected from the third resource set for PSCCH transmission; and The PSCCH transmission is sent using one or more randomly selected resources.

16. The method of claim 15, wherein excluding the one or more resources associated with the one or more PSCCHs from the second resource set comprises: Exclude one or more resources associated with one or more PSCCHs that have the highest signal strength.

17. The method of claim 15, wherein excluding the one or more resources associated with the one or more PSCCHs from the second resource set comprises: One or more resources associated with one or more PSCCHs whose signal strength is higher than a second signal strength threshold are excluded from the second resource set to form a third resource set; as well as Determine whether the amount of resources in the third resource set is equal to or higher than the threshold percentage of the amount of resources in the first resource set.

18. The method of claim 17, further comprising: When the amount of resources in the third resource set is lower than the threshold percentage of the amount of resources in the first resource set, the following steps are performed iteratively until the amount of resources in the third resource set is equal to or higher than the threshold percentage of the amount of resources in the first resource set: Raise the second signal strength threshold to the third signal strength threshold; The third resource set is formed by excluding one or more resources associated with one or more PSCCHs whose signal strength is higher than the third signal strength threshold from the second resource set; as well as Re-determine whether the amount of resources in the third resource set is equal to or higher than the threshold percentage of the amount of resources in the first resource set.

19. The method of claim 17, wherein the resource for the PSCCH transmission is randomly selected from the third resource set based on a threshold percentage that determines that the amount of resources in the third resource set is equal to or greater than the amount of resources in the first resource set.

20. The method of claim 15, further comprising: Based on one or more side link control information (SCI) in one or more initial PSCCH transmissions, the one or more PSCCHs are identified as one or more PSCCH retransmissions.

21. The method of claim 15, further comprising: The one or more PSCCHs are identified based on semi-persistent scheduling (SPS).

22. The method of claim 15, wherein the autonomous sidelink resource selection includes autonomous resource selection in cellular vehicle-to-everything (CV2x) mode 4.

23. The method of claim 15, wherein the first resource set comprises resources within a selected transmission window.

24. The method of claim 15, wherein excluding resources associated with transmissions having signal strengths higher than the first signal strength threshold from the first resource set to form a second resource set further comprises: Exclude the resources indicated in the Side Link Control Information (SCI) within the previous number of subframes.

25. The method of claim 15, wherein the threshold percentage includes twenty percent.

26. The method of claim 15, further comprising: Adjust the default modulation and coding scheme (MCS) and default resource number used for message transmission to avoid selecting resources with Physical Side Link Control Channel (PSCCH) transmission, where The resources randomly selected from the third resource set for the PSCCH transmission include a randomly selected adjusted number of resources.

27. The method of claim 26, wherein adjusting the default MCS and default resource number used for sending messages to avoid selecting resources with PSCCH transmission comprises: Increase the default MCS and decrease the default number of sub-channels so that when selecting a sub-channel from the second resource set, the selection of a sub-channel with PSCCH transmission is avoided.

28. The method of claim 26, wherein adjusting the default MCS and default resource number used for sending messages to avoid selecting resources with PSCCH transmission comprises: Reduce the default MCS and increase the default number of sub-channels so that when selecting sub-channels from the second resource set, unexcluded sub-channels with PSCCH transmissions are avoided.

29. An apparatus for wireless communication, comprising: Components used to perform autonomous sidelink resource selection include: A component for excluding one or more resources associated with transmissions whose signal strength is higher than a first signal strength threshold from a first resource set to form a second resource set; A component for determining a threshold percentage by which the amount of resources in the second resource set is equal to or higher than the amount of resources in the first resource set; A component for excluding one or more resources associated with one or more Physical Side Link Shared Channels (PSSCHs) from a second resource set to form a third resource set, without excluding one or more resources associated with one or more Physical Side Link Control Channels (PSCCHs) associated with one or more Physical Side Link Shared Channels (PSSCHs); and A component for randomly selecting one or more resources from the third resource set for PSCCH transmission; and A component for sending the PSCCH transmission using one or more randomly selected resources.

30. A computer-readable medium for wireless communication, having stored thereon computer-executable code, the computer-executable code comprising: The code used to perform autonomous sidelink resource selection includes: Code for excluding one or more resources associated with transmissions whose signal strength is higher than a first signal strength threshold from the first resource set to form a second resource set; Code used to determine a threshold percentage by which the amount of resources in the second resource set is equal to or higher than the amount of resources in the first resource set; Code for excluding one or more resources associated with one or more Physical Side Link Shared Channels (PSSCHs) from the second resource set, without excluding one or more resources associated with one or more Physical Side Link Control Channels (PSCCHs) associated with one or more Physical Side Link Shared Channels (PSSCHs), to form a third resource set; and Codes for randomly selecting one or more resources from the third resource set for PSCCH transmission; and Code for sending the PSCCH transmission using one or more randomly selected resources.

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