Techniques for Listen-Before-Talk (LBT) Access Mechanisms for Radar Systems

Abstract

This document describes systems, methods, and devices for wireless communication. A wireless device may implement one or more listen-before-talk (LBT) techniques. The wireless device may identify a set of transmission parameters for a signal to be transmitted from the wireless device. The wireless device may generate a first transmission waveform of the signal over a set of radio resources based on the set of transmission parameters. The wireless device may perform LBT at least in part based on the generation of the first transmission waveform. In some cases, performing the LBT includes adjusting a detected signal associated with the set of radio resources at least in part based on the first transmission waveform. The wireless device may transmit the signal based on the result of the LBT.

Description

[0001] Cross-reference

[0002] This patent application claims the benefit of U.S. Provisional Patent Application No. 63 / 003,787, filed Apr. 1, 2020, by GULATI et al. and titled "TECHNIQUES FOR LISTEN BEFORE TALKING (LBT) ACCESS MECHANISMS FOR RADAR SYSTEMS", and U.S. Patent Application No. 17 / 211,598, filed Mar. 24, 2021, by GULATI et al. and titled "TECHNIQUES FOR LISTEN BEFORE TALKING (LBT) ACCESS MECHANISMS FOR RADAR SYSTEMS", each of which has been assigned to the assignee of this application. Field of the Disclosure

[0003] Broadly speaking, the following relates to wireless communication, and more specifically, the following relates to techniques for listen before talk (LBT) access mechanisms for radar systems. Background Art

[0004] Wireless communication systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcasting, etc. These systems may be capable of supporting communication with multiple users by sharing available system resources (e.g., time, frequency, and power). Examples of such multi-access systems include fourth-generation (4G) systems such as Long Term Evolution (LTE) systems, Advanced LTE (LTE-A) systems, or LTE-A Pro systems, and fifth-generation (5G) systems that may be referred to as New Radio (NR) systems. These systems may employ techniques such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), or Discrete Fourier Transform Spread Orthogonal Frequency Division Multiplexing (DFT-S-OFDM). A wireless multi-access communication system may include one or more base stations or one or more network access nodes, each of which simultaneously supports communication for multiple communication devices (which may also be referred to as user equipment (UE)). In some systems, wireless devices such as UEs (e.g., vehicles) may encounter signal interference. As an example, a wireless device may transmit a radar signal and that radar signal may be interfered with by another radar signal from another wireless device, which may result in relatively inaccurate and inefficient signaling in the system. Summary of the Invention

[0005] The described techniques relate to improved methods, systems, devices, and apparatuses that support techniques for a listen-before-talk (LBT) access mechanism for a system (e.g., a radar system). For example, the described techniques provide more reliable signaling (e.g., radar signaling, communication, etc.) by enabling a wireless device to implement an LBT process. The wireless device may perform one or more LBT operations to detect whether radio frequency resources are occupied, which may enable the wireless device to avoid interference (e.g., the wireless device may suppress or transmit a radar signal based on the result of one or more LBT operations indicating whether a resource set is idle for transmission). As described herein, the wireless device may perform such LBT operations based on a waveform generated for a signal (e.g., a radar signal), which may result in more accurate interference measurements for signaling on a resource set. For example, the wireless device may identify a set of transmission parameters (e.g., transmission parameters of a period of a frequency-modulated continuous wave (FMCW) radar signal) and generate a waveform of the signal according to these parameters. The wireless device may mix the generated waveform with received energy (e.g., received energy or a detected signal from performing channel sensing on a resource set) to determine whether transmission of a signal with the generated waveform will cause or be interfered with by another signal from another wireless device. In some examples, the LBT process may be successful (e.g., the interference measurement may meet a threshold) and the wireless device may use the set of transmission parameters to transmit a signal. In some other examples, the LBT process may fail. In such examples, the wireless device may perform another LBT process using a different set of transmission parameters. Additionally or alternatively, the wireless device may select a set of transmission parameters that causes minimal interference to the transmission (e.g., in the case of an LBT failure when multiple sets of transmission parameters fail to meet the threshold).

[0006] A method for wireless communication at a wireless device is described. The method may include: generating a first transmission waveform of a first signal on a radio resource set based on a set of transmission parameters for a transmission from the wireless device; performing LBT using the generated first transmission waveform; and transmitting a second signal based on the set of transmission parameters and the result of the LBT.

[0007] An apparatus for wireless communication at a wireless device is described. The apparatus may include: a processor; a memory coupled to the processor; and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to: generate a first transmission waveform of a first signal on a radio resource set based on a set of transmission parameters for a transmission from the wireless device; perform LBT using the generated first transmission waveform; and transmit a second signal based on the set of transmission parameters and the result of the LBT.

[0008] Describes another apparatus for wireless communication at a wireless device. The apparatus may include: a unit for generating a first transmission waveform of a first signal on a radio resource set based on a set of transmission parameters for a transmission from the wireless device; a unit for performing LBT using the generated first transmission waveform; and a unit for transmitting a second signal based on the set of transmission parameters and the result of the LBT.

[0009] Describes a non-transitory computer-readable medium storing code for wireless communication at a wireless device. The code may include instructions executable by a processor to: generate a first transmission waveform of a first signal on a radio resource set based on a set of transmission parameters for a transmission from the wireless device; perform LBT using the generated first transmission waveform; and transmit a second signal based on the set of transmission parameters and the result of the LBT.

[0010] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include operations, features, units, or instructions for: performing the LBT includes adjusting a detected signal associated with the radio resource set based on the first transmission waveform.

[0011] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include operations, features, units, or instructions for: processing the detected signal and the first transmission waveform to obtain a measurement result; determining that the measurement result satisfies a threshold; and identifying the result of the LBT based on the measurement result that satisfies the threshold.

[0012] In some examples of the methods, apparatuses, or non-transitory computer-readable media described herein, the measurement result may be less than the threshold, and the result of the LBT includes a successful result.

[0013] In some examples of the methods, apparatuses, or non-transitory computer-readable media described herein, the measurement result may be greater than or equal to the threshold, and the result of the LBT includes a failed result.

[0014] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include operations, features, units, or instructions for: using the first transmission waveform to transmit the second signal.

[0015] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include operations, features, units, or instructions for: identifying a second set of transmission parameters of the first signal from the wireless device; generating a second transmission waveform based on the second set of transmission parameters; performing a second LBT based on generating the second transmission waveform, wherein performing the second LBT includes: adjusting a detected signal associated with the radio resource set based on the second transmission waveform; and transmitting the second signal using the second transmission waveform based on a successful result of the second LBT.

[0016] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include operations, features, units, or instructions for: comparing the measurement result of the LBT with a set of measurement results associated with an LBT set; selecting one or more transmission parameters based on the comparison; and transmitting the second signal according to the selected one or more transmission parameters.

[0017] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include operations, features, units, or instructions for: determining that the one or more transmission parameters correspond to a measurement result that may be the minimum value in the set of measurement results, wherein selecting the one or more transmission parameters may be based on the determination.

[0018] In some examples of the methods, apparatuses, or non-transitory computer-readable media described herein, the set of transmission parameters may be the last set of transmission parameters in a group of multiple sets of transmission parameters.

[0019] In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, performing the LBT may include operations, features, units, or instructions for: sensing a channel associated with the radio resource set during a first time period; and identifying a detected signal based on sensing the channel, wherein performing the LBT may be based on the detected signal.

[0020] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include operations, features, units, or instructions for: identifying the first time period based on a configuration of the wireless device, information received from another wireless device, a confidence threshold, or any combination thereof.

[0021] In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, transmitting the second signal may include operations, features, units, or instructions for: transmitting a frequency-modulated continuous-wave radar signal.

[0022] In some examples of the methods, apparatuses, or non-transitory computer-readable media described herein, the wireless device includes a vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 FIG. shows an example of a system for wireless communication that supports techniques for a listen-before-talk (LBT) access mechanism for a radar system, in accordance with various aspects of the present disclosure.

[0024] Figure 2 FIG. shows an example of a system that supports techniques for an LBT access mechanism for a radar system, in accordance with various aspects of the present disclosure.

[0025] Figure 3 FIG. shows an example of a timeline that supports techniques for an LBT access mechanism for a radar system, in accordance with various aspects of the present disclosure.

[0026] Figure 4 FIG. shows an example of a flowchart that supports techniques for an LBT access mechanism for a radar system, in accordance with various aspects of the present disclosure.

[0027] Figure 5 and Figure 6 FIG. shows a block diagram of a device that supports techniques for an LBT access mechanism for a radar system, in accordance with various aspects of the present disclosure.

[0028] Figure 7 FIG. shows a block diagram of a communication manager that supports techniques for an LBT access mechanism for a radar system, in accordance with various aspects of the present disclosure.

[0029] Figure 8 FIG. shows a diagram of a system that includes a device that supports techniques for an LBT access mechanism for a radar system, in accordance with various aspects of the present disclosure.

[0030] Figure 9 and Figure 10 FIG. shows a flowchart that illustrates a method that supports techniques for an LBT access mechanism for a radar system, in accordance with various aspects of the present disclosure. DETAILED DESCRIPTION

[0031] Some systems (e.g., wireless communication systems) can implement radar signaling. For example, radar can be used for ranging and other purposes (e.g., environment and object detection) by sending radar signals from a device and observing the reflected (e.g., detected) radar signals to estimate the properties of nearby targets (e.g., objects, vehicles, people, obstacles, or any other targets). Such properties can include the distance, speed, and angular position of nearby targets. For example, a radar system can be implemented to detect aircraft, ships, vehicles, weather formations, terrain, and other objects. Examples of radar signaling used in such systems can include frequency-modulated continuous wave (FMCW) radar signaling, phase-modulated continuous wave (PMCW) radar signaling, and other examples of radar signaling. In some examples, a wireless device (e.g., a user equipment (UE), a vehicle, or any other wireless device) can use radar as a sensor input enabling advanced driver assistance systems (ADAS) and autonomous driving. However, in some cases, radar transmissions from other devices can cause significant interference to signals in the system, which can degrade target detection performance, communication between devices, etc.

[0032] According to the techniques described herein, a wireless device such as a UE (e.g., a vehicle) can implement one or more listen-before-talk (LBT) schemes in a wireless communication system (e.g., a radar system). The wireless device can perform one or more LBT operations to determine whether a resource is occupied (e.g., detect if there is a signal being transmitted by another device on the resource), which can enable the wireless device to avoid interference. For example, the wireless device can determine whether to send or avoid sending a radar signal based on the results of one or more LBT operations indicating whether a set of resources is idle for transmission. As described herein, the wireless device can perform such LBT operations based on the waveform generated for the signal that the device intends to send on the set of resources, which can result in more accurate interference measurements for the signaling on the set of resources. For example, the wireless device can identify a set of transmission parameters (e.g., the "chirp" parameters of an FMCW radar signal period) and use the parameters to generate a first waveform. The wireless device can use the generated first waveform to adjust the LBT process. For example, the wireless device can adjust the detected signal based on the first waveform. Adjusting the detected signal can include mixing the received energy associated with the detected signal with the generated first waveform. The output of the mixing of the detected signal and the waveform can be processed to obtain a measurement of the interference (e.g., interference to the detected signal) caused by sending the waveform on the set of resources.

[0033] In some examples, a wireless device may compare measurement results to a threshold and determine that the threshold is met (e.g., a successful result of an LBT procedure). In such examples, the wireless device may use a first waveform to transmit a signal according to the set of transmission parameters. In some other examples, the wireless device may compare measurement results to a threshold and determine that the measurement results do not meet the threshold (e.g., a failure result of an LBT procedure). In such examples, the wireless device may use a second set of transmission parameters to perform another LBT procedure. If the LBT procedure using the second set of transmission parameters (e.g., mixing a second waveform with the detected signal) is successful, the wireless device may transmit a signal according to the second set of transmission parameters. If the LBT procedure using the second set of transmission parameters is not successful, then in some examples, the wireless device may select a third set of transmission parameters and attempt LBT access again (and so on until a successful result is obtained). Additionally or alternatively, the wireless device may select the set of transmission parameters that results in the least interference measurement and transmit the waveform corresponding to the selected set of transmission parameters (e.g., in the case of an LBT failure when the wireless device determines that none of the multiple sets of parameters will result in a successful LBT procedure).

[0034] Aspects of the present disclosure are first described in the context of a wireless communication system. Aspects of the present disclosure are then described in the context of a system and timeline. Aspects of the present disclosure are further illustrated and described with reference to apparatus diagrams, system diagrams, and flowcharts related to techniques for an LBT access mechanism for a radar system.

[0035] Figure 1 An example of a wireless communication system 100 that supports techniques for an LBT access mechanism for a radar system in accordance with aspects of the present disclosure is shown. The wireless communication system 100 may include one or more base stations 105, one or more UEs 115, and a core network 130. In some examples, the wireless communication system 100 may be a Long Term Evolution (LTE) network, an Advanced LTE (LTE-A) network, an LTE-A Pro network, or a New Radio (NR) network. In some examples, the wireless communication system 100 may support enhanced broadband communication, ultra-reliable (e.g., mission-critical) communication, low-latency communication, communication with low-cost and low-complexity devices, or any combination thereof.

[0036] Base stations 105 may be dispersed throughout a geographical area to form a wireless communication system 100 and may be devices having different forms or having different capabilities. The base stations 105 and the UEs 115 may communicate wirelessly via one or more communication links 125. Each base station 105 may provide a coverage area 110, and the UEs 115 and the base stations 105 may establish one or more communication links 125 over the coverage area 110. The coverage area 110 may be an example of a geographical area over which the base stations 105 and the UEs 115 may support communication of signals according to one or more radio access technologies.

[0037] The UEs 115 may be dispersed throughout the coverage area of the wireless communication system 100, and each UE 115 may be stationary, mobile, or both stationary and mobile at different times. The UEs 115 may be devices having different forms or having different capabilities. Figure 1 Some example UEs 115 are shown. The UEs 115 described herein may be capable of communicating with various types of devices, such as other UEs 115, base stations 105, or network devices (e.g., core network nodes, relay devices, integrated access and backhaul (IAB) nodes, or other network devices), as Figure 1 shown.

[0038] The base stations 105 may communicate with the core network 130, communicate with each other, or do both. For example, the base stations 105 may be connected to the core network 130 via one or more backhaul links 120 (e.g., via S1, N2, N3, or other interfaces). The base stations 105 may communicate with each other directly (e.g., directly between the base stations 105), indirectly (e.g., via the core network 130), or both via the backhaul links 120 (e.g., via X2, Xn, or other interfaces). In some examples, the backhaul links 120 may be or include one or more wireless links.

[0039] One or more of the base stations 105 described herein may include or may be referred to by those skilled in the art as a base station transceiver, radio base station, access point, radio transceiver, Node B, eNodeB (eNB), next-generation Node B, or Gigabit Node B (any of which may be referred to as a gNB), home Node B, home eNodeB, or other suitable terms.

[0040] The UE 115 may include or may be referred to as a mobile device, wireless device, remote device, handheld device, or subscriber device, or some other suitable term, where "device" may also be referred to as a unit, station, terminal, or client, etc. The UE 115 may also include or may be referred to as a personal electronic device, such as a cellular phone, personal digital assistant (PDA), tablet computer, laptop computer, or personal computer. In some examples, the UE 115 may include or be referred to as a wireless local loop (WLL) station, Internet of Things (IoT) device, Internet of Everything (IoE) device, or machine type communication (MTC) device, etc., which may be implemented in various objects such as appliances, vehicles, meters, etc.

[0041] The UE 115 described herein may be capable of communicating with various types of devices, such as other UE 115s that may sometimes act as relays, as well as the base station 105 and network devices, which include, for example, Figure 1 the macro eNB or gNB, small cell eNB or gNB, or relay station as shown.

[0042] The UE 115 and the base station 105 may wirelessly communicate with each other via one or more communication links 125 over one or more carriers. The term "carrier" may refer to a collection of radio spectrum resources having a defined physical layer structure for supporting the communication link 125. For example, a carrier for the communication link 125 may include a portion (e.g., bandwidth part (BWP)) of a radio frequency spectrum band that operates according to one or more physical layer channels for a given radio access technology (e.g., LTE, LTE-A, LTE-A Pro, NR). Each physical layer channel may carry acquisition signaling (e.g., synchronization signals, system information), control signaling for coordinating the operation of the carrier, user data, or other signaling. The wireless communication system 100 may use carrier aggregation or multi-carrier operation to support communication with the UE 115. The UE 115 may be configured with multiple downlink component carriers and one or more uplink component carriers according to a carrier aggregation configuration. Carrier aggregation may be used for both frequency division duplex (FDD) and time division duplex (TDD) component carriers.

[0043] The signal waveform transmitted on a carrier can be composed of multiple subcarriers (e.g., using a multi-carrier modulation (MCM) technique such as orthogonal frequency division multiplexing (OFDM) or discrete Fourier transform spread OFDM (DFT-S-OFDM)). In a system employing an MCM technique, a resource unit can include a symbol period (e.g., the duration of a modulated symbol) and a subcarrier, where the symbol period and the subcarrier spacing are inversely related. The number of bits carried by each resource unit can depend on the modulation scheme (e.g., the order of the modulation scheme, the coding rate of the modulation scheme, or both). Thus, the more resource units the UE 115 receives and the higher the order of the modulation scheme, the higher the data rate of the UE 115 can be. Wireless communication resources can refer to a combination of radio spectrum resources, time resources, and space resources (e.g., spatial layers or beams), and the use of multiple spatial layers can also increase the data rate or data integrity for communicating with the UE 115.

[0044] The time interval of the base station 105 or the UE 115 can be expressed as a multiple of a basic time unit, which, for example, can refer to T s = 1 / (Δf max ·N f ) seconds of sampling period, where Δf max can represent the maximum supported subcarrier spacing, and N f can represent the maximum supported discrete Fourier transform (DFT) size. The time interval of the communication resources can be organized according to radio frames, and each radio frame has a specified duration (e.g., 10 milliseconds (ms)). Each radio frame can be identified by a system frame number (SFN) (e.g., ranging from 0 to 1023).

[0045] Each frame can include a plurality of consecutively numbered subframes or time slots, and each subframe or time slot can have the same duration. In some examples, a frame can be divided into (e.g., in the time domain) subframes, and each subframe can be further divided into a plurality of time slots. Alternatively, each frame can include a variable number of time slots, and the number of time slots can depend on the subcarrier spacing. Each time slot can include a plurality of symbol periods (e.g., depending on the length of the cyclic prefix before each symbol period). In some wireless communication systems 100, a time slot can be further divided into a plurality of mini-slots containing one or more symbols. Excluding the cyclic prefix, each symbol period can contain one or more (e.g., N f ) sampling periods. The duration of the symbol period can depend on the subcarrier spacing or the operating frequency band.

[0046] A subframe, time slot, mini-slot, or symbol can be the smallest scheduling unit (e.g., in the time domain) of the wireless communication system 100 and can be referred to as a transmission time interval (TTI). In some examples, the TTI duration (e.g., the number of symbol periods in the TTI) can be variable. Additionally or alternatively, the smallest scheduling unit of the wireless communication system 100 can be dynamically selected (e.g., in a burst of shortened TTIs (sTTIs)).

[0047] Physical channels can be multiplexed on a carrier according to various techniques. For example, using one or more of time division multiplexing (TDM) techniques, frequency division multiplexing (FDM) techniques, or hybrid TDM-FDM techniques, physical control channels and physical data channels can be multiplexed on a downlink carrier. A control region for a physical control channel (e.g., a control resource set (CORESET)) can be defined by the number of symbol periods and can extend across the system bandwidth of the carrier or a subset of the system bandwidth of the carrier. One or more control regions (e.g., CORESETs) can be configured for a set of UEs 115. For example, one or more UEs 115 can monitor or search a control region for control information according to one or more search space sets, and each search space set can include one or more control channel candidates arranged in a cascaded manner at one or more aggregation levels. The aggregation level for a control channel candidate can refer to a plurality of control channel resources (e.g., control channel elements (CCEs)) associated with the coded information for a control information format having a given payload size. The search space set can include a common search space set configured to send control information to a plurality of UEs 115 and a UE-specific search space set for sending control information to a specific UE 115.

[0048] In some examples, the base station 105 can be movable and thus provide communication coverage for a mobile geographic coverage area 110. In some examples, different geographic coverage areas 110 associated with different technologies can overlap, but different geographic coverage areas 110 can be supported by the same base station 105. In other examples, overlapping geographic coverage areas 110 associated with different technologies can be supported by different base stations 105. The wireless communication system 100 can include, for example, a heterogeneous network in which different types of base stations 105 provide coverage for various geographic coverage areas 110 using the same or different radio access technologies.

[0049] The wireless communication system 100 can be configured to support ultra-reliable communication or low-latency communication or various combinations thereof. For example, the wireless communication system 100 can be configured to support ultra-reliable low-latency communication (URLLC) or mission-critical communication. The UE 115 can be designed to support ultra-reliability, low latency, or critical functions (e.g., mission-critical functions). Ultra-reliable communication can include private communication or group communication and can be supported by one or more mission-critical services (e.g., mission-critical push-to-talk (MCPTT), mission-critical video (MCVideo), or mission-critical data (MCData)). Support for mission-critical functions can include prioritization of services, and mission-critical services can be used for public safety or general commercial applications. The terms ultra-reliable, low-latency, mission-critical, and ultra-reliable low-latency can be used interchangeably herein.

[0050] In some examples, the UE 115 is also capable of directly communicating with other UEs via a device-to-device (D2D) communication link 135 (e.g., using a peer-to-peer (P2P) or D2D protocol). One or more UEs 115 utilizing D2D communication can be within the geographical coverage area 110 of the base station 105. Other UEs 115 in such a group can be located outside the geographical coverage area 110 of the base station 105 or may not be able to receive transmissions from the base station 105. In some examples, a group of UEs 115 communicating via D2D communication can use a one-to-many (1:M) system in which each UE 115 transmits to every other UE 115 in the group. In some examples, the base station 105 facilitates the scheduling of resources for D2D communication. In other cases, D2D communication is performed between the UEs 115 without the participation of the base station 105.

[0051] In some systems, the D2D communication link 135 can be an example of a communication channel (e.g., a sidelink communication channel) between vehicles (e.g., the UE 115). In some examples, vehicles can communicate using vehicle-to-everything (V2X) communication, vehicle-to-vehicle (V2V) communication, or some combination of these. Vehicles can emit information related to traffic conditions, signal scheduling, weather, safety, emergencies, or any other information related to the V2X system. In some examples, vehicles in a V2X system can communicate with roadside infrastructure (e.g., a roadside unit) or communicate with the network via one or more network nodes (e.g., the base station 105) using vehicle-to-network (V2N) communication, or communicate with both.

[0052] The core network 130 can provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. The core network 130 can be an Evolved Packet Core (EPC) or a 5G Core (5GC), which can include at least one control plane entity that manages access and mobility (e.g., Mobility Management Entity (MME), Access and Mobility Management Function (AMF)), and at least one user plane entity that routes packets or interconnects to an external network (e.g., Serving Gateway (S-GW), Packet Data Network (PDN) Gateway (P-GW), or User Plane Function (UPF)). The control plane entity can manage Non-Access Stratum (NAS) functions such as mobility, authentication, and bearer management for a UE 115 served by a base station 105 associated with the core network 130. User IP packets can be transported through the user plane entity, which can provide IP address allocation and other functions. The user plane entity can be connected to a network operator IP service 150. The operator IP service 150 can include access to the Internet, an intranet, an IP Multimedia Subsystem (IMS), or a packet-switched streaming service.

[0053] Some network devices (such as base station 105) can include subcomponents (such as access network entity 140), which can be an example of an access node controller (ANC). Each access network entity 140 can communicate with a UE 115 through one or more other access network transport entities 145, which can be referred to as radio heads, intelligent radio heads, or transmit / receive points (TRPs). Each access network transport entity 145 can include one or more antenna arrays. In some configurations, the various functions of each access network entity 140 or base station 105 can be distributed across various network devices (e.g., radio heads and ANCs) or consolidated into a single network device (e.g., base station 105).

[0054] The wireless communication system 100 can operate using one or more frequency bands, e.g., in the range of 300 megahertz (MHz) to 300 gigahertz (GHz). For example, the region from 300 MHz to 3 GHz is known as the Ultra-High Frequency (UHF) region or the decimeter band because the wavelength range is from approximately one decimeter to one meter in length. UHF waves can be blocked or redirected by buildings and environmental features, yet the waves can penetrate structures sufficiently to enable a macro cell to serve a UE 115 located indoors. Compared to transmissions using lower frequencies and longer waves in the spectrum below 300 MHz in the High Frequency (HF) or Very High Frequency (VHF) portions, UHF wave transmissions can be associated with smaller antennas and shorter distances (e.g., less than 100 kilometers).

[0055] The wireless communication system 100 can utilize both licensed and unlicensed radio frequency bands. For example, the wireless communication system 100 can employ licensed-assisted access (LAA) or LTE-unlicensed (LTE-U) radio access technologies or NR technologies in unlicensed bands such as the 5 GHz industrial, scientific, and medical (ISM) band. When operating in an unlicensed radio frequency band, wireless devices (such as base station 105 and UE 115) can adopt a listen-before-talk (LBT) procedure to ensure that the frequency channel is idle before transmitting data. In some examples, operation in the unlicensed band can be based on a carrier aggregation configuration in combination with a component carrier operating in a licensed band (e.g., LAA). Operations in the unlicensed spectrum can include downlink transmissions, uplink transmissions, peer-to-peer (P2P) transmissions, or device-to-device (D2D) transmissions, and so on.

[0056] Base station 105 or UE 115 can be equipped with multiple antennas, which can be used to adopt techniques such as transmit diversity, receive diversity, multiple-input multiple-output (MIMO) communication, or beamforming. The antennas of base station 105 or UE 115 can be located within one or more antenna arrays or antenna panels, which can support MIMO operations or transmit or receive beamforming. For example, one or more base station antennas or antenna arrays can be co-located at an antenna assembly (such as an antenna tower). In some examples, the antennas or antenna arrays associated with base station 105 can be located at different geographical locations. Base station 105 can have an antenna array that has multiple rows and columns of antenna ports that base station 105 can use to support beamforming for communication with UE 115. Similarly, UE 115 can have one or more antenna arrays that can support various MIMO or beamforming operations. Additionally or alternatively, an antenna panel can support radio frequency beamforming for signals transmitted via an antenna port.

[0057] Beamforming (which can also be referred to as spatial filtering, directional transmission, or directional reception) is a signal processing technique that can be used at a transmitting device or a receiving device (e.g., base station 105, UE 115) to shape an antenna beam or manipulate an antenna beam (e.g., a transmit beam, a receive beam) along a spatial path between the transmitting device and the receiving device. Beamforming can be achieved by combining signals transmitted via the antenna elements of an antenna array such that some signals propagating in some directions with respect to the antenna array experience constructive interference while other signals experience destructive interference. The adjustment of the signals transmitted via the antenna elements can include the transmitting device or the receiving device applying an amplitude offset, a phase offset, or both to the signals carried via the antenna elements associated with the device. The adjustment associated with each of these antenna elements can be defined by a set of beamforming weights associated with a certain direction (e.g., with respect to the antenna array of the transmitting device or receiving device or with respect to some other direction).

[0058] In some examples, devices in a wireless communication system 100 (e.g., a UE 115 such as a vehicle, a base station 105, etc.) may implement one or more LBT schemes described herein. For example, a wireless device may perform an LBT procedure to identify whether a set of radio frequency resources is occupied (e.g., whether another wireless device is utilizing the resources to transmit a signal, such as a radar signal, communication, etc.). The LBT procedure may include performing an energy sensing of the resources to determine whether the resources are idle for transmission. The wireless device may determine to transmit or avoid transmitting a signal based on the result of the LBT operation indicating whether the set of resources is idle for transmission.

[0059] According to examples described herein, a wireless device may perform such an LBT operation based on a waveform generated for a signal that the device intends to transmit on a set of resources, which may result in a more accurate interference measurement for signaling on the set of resources. For example, a wireless device may identify a set of transmission parameters (e.g., the "chirp" parameter of an FMCW radar signal period) and use the parameter to generate a first waveform for transmitting a signal (e.g., a "chirp" radar signal). The wireless device may use the generated first waveform to perform the LBT procedure. For example, the wireless device may adjust a detected signal (e.g., the energy received from a channel sensing procedure) based on the first waveform. Adjusting the detected signal may include mixing the first waveform and the received energy associated with the detected signal. The output of the mixing of the detected signal and the waveform may be processed to obtain a measurement result of the interference (e.g., interference to the detected signal) caused by transmitting the waveform on the set of resources.

[0060] In some examples, a wireless device may compare measurement results to a threshold and determine that the threshold is met (e.g., a successful result of an LBT procedure). In such examples, the wireless device may use a first waveform to transmit a signal according to the set of transmission parameters. In some other examples, the wireless device may compare the measurement results to a threshold and determine that the measurement results do not meet the threshold (e.g., a failed result of an LBT procedure). In such examples, the wireless device may use a second set of transmission parameters to perform another LBT procedure. If the LBT procedure using the second set of transmission parameters (e.g., mixing a second waveform with the detected signal) is successful, the wireless device may transmit a signal according to the second set of transmission parameters. If the LBT procedure using the second set of transmission parameters is not successful, then in some examples, the wireless device may select a third set of transmission parameters and attempt LBT access again (and so on until a successful result is obtained). Additionally or alternatively, the wireless device may select the set of transmission parameters that results in the least interference measurement and transmit the waveform corresponding to the selected set of transmission parameters (e.g., in the case of an LBT failure when the wireless device determines that none of the multiple sets of parameters will result in a successful LBT procedure).

[0061] Figure 2 FIG. 200 illustrates an example of a system 200 that supports techniques for an LBT access mechanism for a radar system, in accordance with various aspects of the present disclosure. In some examples, system 200 may implement aspects of wireless communication system 100. For example, system 200 may include UE 115-a and UE 115-b, which may be examples of the UE 115 or other wireless devices described with reference Figure 1 to. System 200 may illustrate an example of an LBT scheme that considers the transmission waveform of a signal.

[0062] UE 115-a and UE 115-b can respectively send signals 205-a and 205-b. For example, UE 115-a can identify signal 205-a for transmission. In some cases, UE 115-a can send signal 205-a in full-duplex mode (e.g., data or radar signals can be sent and received simultaneously at UE 115-a or UE 115-b). As an illustrative example, signal 205-a can be an example of an FMCW radar signal, which can endow UE 115-a with various functions (e.g., ranging, environment and object detection, ADAS, autonomous driving, etc.). However, in some examples, signal 205-a and signal 205-b may interfere with each other or interfere with other signals 205. For example, UE 115-a can be an example of a vehicle moving towards UE 115-b. UE 115-b can send signal 205-b (e.g., an FMCW radar signal) at the time or resource when UE 115-a sends signal 205-a. In such an example, signal 205-b may cause relatively strong interference to signal 205-a from UE 115-a (e.g., signal 205-b may prevent the reception of the reflected signal 205-a), and vice versa, which may degrade ranging accuracy and object detection.

[0063] Therefore, the techniques described herein can enable UE 115-a and 115-b to implement LBT operations in a radar system, for example, which can reduce the likelihood of interference in system 200 and lead to more efficient signaling. Additionally or alternatively, UE 115-a and UE 115-b can implement one or more waveform-aware LBT schemes. For example, UE 115-a can perform the LBT process based on the waveform generated for signal 205-a, which can result in relatively more accurate channel occupancy detection.

[0064] UE 115-a can identify a set of transmission parameters for the transmission waveform of signal 205-a. In some examples, the transmission parameters can be examples of the "chirp" parameters of an FMCW radar signal period. In some examples, the transmission parameters can include carrier frequency, bandwidth scan range (e.g., the waveform can be transmitted in a 1 GHz range, a 1.5 GHz range, and other examples of the bandwidth scan range), scan time (e.g., UE 115-a can complete the bandwidth scan of the waveform within 2 microseconds, 6 microseconds, 12 microseconds, etc.), scan direction (e.g., the "chirp" of the waveform can point from an angle of 77 degrees from UE 115-a to an angle of 78 degrees from UE 115-a, or from 78 degrees to 77 degrees, although any parameter indicating the scan direction can be used), and other examples of transmission parameters. UE 115-a can utilize this set of transmission parameters to determine (e.g., generate) the first waveform of signal 205-a. For example, UE 115-a can generate an analog transmission waveform, but can avoid transmitting the signal for a period of time (e.g., zero power can be achieved using the transmission waveform until the LBT cycle is completed).

[0065] UE 115-a can use the generated waveform to perform the LBT process. For example, UE 115-a can perform channel sensing on a set of resources (e.g., the resources that UE 115-a intends to use to transmit the generated waveform) to determine whether the resources are occupied by UE115-b. UE 115-a can adjust the detected signal based on the generated waveform (e.g., the energy received from the channel sensing process). Adjusting the detected signal can include mixing the generated waveform and the received energy associated with the detected signal. Additionally or alternatively, adjusting the detected signal can include processing the output of the mixing of the waveform and the detected signal (e.g., mixer output). Such processing can include filtering and fast Fourier transform (FFT) of the output, which can produce measurement results (e.g., the value of the peak of the spectrum such as the mixing of the waveform and the detection signal). In some examples, the measurement can indicate the possible interference (e.g., mutual interference) between signal 205-a with the generated waveform and signal 205-b from UE 115-b.

[0066] In some examples, UE 115-a may compare the measurement result with a threshold. For example, UE 115-a may compare the threshold value with the peak of the spectrum obtained by processing the mixer output of the generated waveform and the energy received on the resource set. UE 115-a may determine whether the threshold is met based on this comparison. For example, UE 115-a may determine that the LBT process is successful (e.g., the comparison result of the LBT process indicates that transmitting signal 205-a using the waveform generated according to this set of transmission parameters will result in a relatively low amount of interference to signal 205-b).

[0067] Additionally or alternatively, UE 115-a may compare the measurement result with a threshold and determine that the measurement result fails to meet the threshold (e.g., the result of a failed LBT process may indicate that transmitting signal 205-a using the waveform generated according to this set of transmission parameters will result in a relatively high amount of interference to signal 205-b). In such an example, UE 115-a may perform another LBT process using a second set of transmission parameters. If the LBT process using the second set of transmission parameters (e.g., mixing a second waveform different from the previously generated waveform with the detected signal) is successful, UE 115-a may transmit signal 205-a according to the second set of transmission parameters. If the LBT process using the second set of transmission parameters is not successful, in some examples, UE 115-a may select a third set of transmission parameters and attempt LBT access again (and so on until a successful result is obtained).

[0068] In some examples, UE 115-a may determine that an LBT failure has occurred. For example, UE 115-a may be configured with a threshold number of LBT processes to attempt (e.g., UE 115-a may attempt five LBT processes with five different parameter sets, or any other number of attempts). Additionally or alternatively, UE 115-a may have attempted the LBT process for all possible sets of transmission parameters and failed to obtain a successful result for each set of transmission parameters (e.g., each waveform generated for each attempt may result in an interference measurement result higher than the threshold). UE 115-a may select the set of transmission parameters that results in the minimum interference measurement result (e.g., the set of transmission parameters of one or more LBT processes that results in the minimum peak interference to signal 205-b). UE 115-a may transmit the waveform corresponding to the selected set of transmission parameters.

[0069] Figure 3An example of timeline 300 is shown that supports techniques for a LBT access mechanism for a radar system, in accordance with various aspects of the present disclosure. In some examples, timeline 300 may implement aspects of wireless communication system 100. For example, timeline 300 may show an example communication (e.g., radar signaling) of UEs 115-c and 115-d implementing a LBT scheme, which may be an example of UEs 115 or other wireless devices as described in reference Figure 1 and Figure 2 description.

[0070] UE 115-c may be an example of a wireless device (e.g., a vehicle) that occupies a resource set for transmission 310-a. For example, UE 115-c may transmit FMCW radar signals over multiple durations 305, as shown. UE 115-d may be an example of a wireless device that implements a LBT scheme as described herein to mitigate or avoid interference with transmission 310-a.

[0071] For example, UE 115-d may determine a first waveform based on a first set of parameters and perform a LBT procedure during reception 315-a of duration 305-a. As an example, UE 115-d may use the first set of parameters to generate a first waveform for a first signal intended to be transmitted. UE 115-d may perform LBT as described herein with reference to Figure 2The described LBT process. For example, UE115-d may mix the first waveform with the received energy from a set of sensing resources. UE 115-d may compare the interference measurement result with a threshold based on the mixing of the waveform and the received energy. As shown in timeline 300, UE 115-d may determine that the LBT process using the first set of transmission parameters (e.g., the first waveform) results in an interference measurement that fails to meet the threshold (e.g., the result of an LBT process failure). UE 115-d may attempt a second LBT process based on the interference measurement result failing to meet the threshold. For example, UE 115-d may determine a second waveform based on the second set of parameters and perform the second LBT process during reception 315-b of duration 305-b. In some examples, UE 115-d may identify the time period during which reception 315-a or reception 315-b is performed. For example, UE 115-d may perform the LBT process during a certain time period based on pre-configuration of UE 115-d. In some examples, the time period may be determined dynamically. For example, UE 115-d may perform reception, such as reception 315-a and reception 315-b, until a confidence level is met. For example, UE 115-d may perform energy sensing and mix the received energy (e.g., the detected signal) with the generated waveform during a certain time period until UE 115-d reaches a confidence level that the resource is occupied (e.g., meets a confidence threshold), a confidence level that the mixing of the received energy and the waveform is above or below a threshold, etc. In some examples, duration 305-a and duration 305-b may be different durations (e.g., due to testing different waveforms, duration 305-a meets a certain confidence threshold relatively faster than duration 305-b, etc.).

[0072] As shown in timeline 300, UE 115-d may determine that the second LBT process is successful (e.g., the interference measurement result using the second waveform meets the threshold). UE 115-d may perform transmission 310-b using the second waveform (e.g., according to the second set of parameters) during duration 305-c based on the successful result of the LBT process. For example, UE 115-d may use the waveform that caused the successful LBT process (e.g., the second waveform, the first waveform, or other examples of waveforms) to send the second signal.

[0073] Figure 4 An example of a flowchart is shown that supports techniques for an LBT access mechanism for a radar system according to various aspects of the present disclosure. In some examples, flowchart 400 may implement aspects of wireless communication system 100. For example, flowchart 400 may be implemented by a wireless device (e.g., UE 115) as described with reference to Figures 1 to 3 the wireless device described above.

[0074] At 405, a wireless device may identify a set of transmission parameters. The set of transmission parameters may be an example of the transmission parameters described herein with reference to Figures 1 to 3 those described. At 410, the wireless device may use the set of transmission parameters for transmission from the wireless device to generate a first transmission waveform of a first signal over a set of radio resources, as described herein with reference to Figures 1 to 3 those described.

[0075] At 415, the wireless device may perform a LBT procedure as described herein with reference to Figures 1 to 3 those described. In some examples, the LBT procedure may use the generated waveform and / or the set of transmission parameters, which may enable more accurate interference measurements (e.g., interference between signal 205-a and signal 205-b, and other interference examples). For example, the wireless device may process the waveform and the received energy from the LBT procedure as described with reference to Figure 2 those described.

[0076] At 420, the wireless device may determine the result of the LBT procedure performed at 415. In some examples, the wireless device may determine that the result is a successful result. In such examples, at 425, the wireless device may transmit a signal over the set of resources using the transmission waveform generated at 410 based on the set of transmission parameters and the successful result (e.g., the wireless device may use the transmission waveform of the first signal to transmit a second signal).

[0077] In some other examples, the wireless device may determine at 415 that the result of the LBT procedure is a failed result. In some examples, the wireless device may repeat 405 to 420 based on the failed result. For example, the wireless device may attempt LBT access for different parameter sets and repeat the process until a successful result is obtained. The wireless device may use the waveform and the set of parameters that result in a successful LBT procedure to transmit the signal. In some examples, the wireless device may determine that an LBT failure has occurred, as described with reference to Figure 2 those described. For example, the wireless device may have exhausted the possible sets of parameters (e.g., a configured number of LBT attempts have been performed, or multiple possible sets of parameters have resulted in interference measurement results that fail to meet a threshold). That is, the set of transmission parameters used to generate the waveform at 410 may be the last set of transmission parameters for one or more LBT procedures.

[0078] At 430, the wireless device may select a set of transmission parameters (e.g., from multiple sets of transmission parameters that have been used for previous LBT procedures). In some examples, selecting the set of transmission parameters may include: comparing the interference measurement result from 415 with a set of interference measurement results associated with different waveforms. The wireless device may select the set of transmission parameters that results in the least interference (e.g., the minimum interference measurement result in the set of interference measurement results). At 435, the wireless device may use the transmission waveform associated with the selected set of transmission parameters to send a signal (e.g., the wireless device may use the transmission waveform associated with the selected set of transmission parameters to send a second signal).

[0079] Figure 5 FIG. 500 is a block diagram of a device 505 that illustrates techniques in accordance with various aspects of the present disclosure that support an LBT access mechanism for a radar system. The device 505 may be an example of an aspect of the wireless device (e.g., UE 115 such as a vehicle) described herein. The device 505 may include a receiver 510, a communication manager 515, and a transmitter 520. The device 505 may also include a processor. Each of these components may communicate with each other (e.g., via one or more buses).

[0080] The receiver 510 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, information, etc. related to techniques for an LBT access mechanism for a radar system). The information may be passed to other components of the device 505. The receiver 510 may be an example of aspects of the transceiver 820 described in Figure 8 reference. The receiver 510 may use a single antenna or an antenna array.

[0081] The communication manager 515 may generate a first transmission waveform of a first signal on a radio resource set based on a set of transmission parameters for a transmission from the wireless device; perform LBT using the generated first transmission waveform; and send a second signal based on the set of transmission parameters and the result of the LBT. The communication manager 515 may be an example of an aspect of the communication manager 810 described herein.

[0082] The communication manager 515 or its sub-components may be implemented in hardware, code executed by a processor (e.g., software or firmware), or any combination thereof. If implemented in code executed by a processor, the communication manager 515 or its sub-components may be executed by a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described in the present disclosure.

[0083] The communication manager 515 or its subcomponents can physically be located in various positions, including being distributed such that portions of the functionality are implemented by one or more physical components at different physical locations. In some examples, according to aspects of the present disclosure, the communication manager 515 or its subcomponents can be separate and distinct components. In some examples, according to aspects of the present disclosure, the communication manager 515 or its subcomponents can be combined with one or more other hardware components, including but not limited to input / output (I / O) components, transceivers, network servers, another computing device, one or more other components described in the present disclosure, or combinations thereof.

[0084] The actions performed by the communication manager 515 as described herein can be implemented to achieve one or more potential advantages. For example, the communication manager 515 can implement one or more LBT schemes (e.g., LBT operations) in a radar system, for example. Such LBT schemes can enable a UE (e.g., a vehicle) to avoid interference in the radar system, which can result in relatively efficient communication, enhanced system performance, and radar detection, among other advantages. Additionally or alternatively, the actions performed by the communication manager 515 can be implemented at the processor of the UE to achieve one or more potential benefits. For example, the processor can enable the UE to use a relatively short time period for the LBT process based on a confidence threshold as described herein, which can reduce processing power and other potential benefits.

[0085] The transmitter 520 can send signals generated by other components of the device 505. In some examples, the transmitter 520 can be co-located with the receiver 510 in a transceiver module. For example, the transmitter 520 can be an example of aspects of the transceiver 820 described in reference Figure 8 to. The transmitter 520 can use a single antenna or an antenna array.

[0086] Figure 6 FIG. 600 is a block diagram of a device 605 that supports techniques for an LBT access mechanism for a radar system, according to aspects of the present disclosure. The device 605 can be an example of an aspect of the device 505 or a wireless device (e.g., a UE 115 such as a vehicle) described herein. The device 605 can include: a receiver 610, a communication manager 615, and a transmitter 640. The device 605 can also include a processor. Each of these components can communicate with each other (e.g., via one or more buses).

[0087] The receiver 610 can receive information such as packets, user data, or control information associated with respective information channels (e.g., control channels, data channels, information related to the LBT access mechanism technology for a radar system, etc.). The information can be passed to other components of the device 605. The receiver 610 can be an example of aspects of the transceiver 820 described with reference to Figure 8 The receiver 610 can use a single antenna or an antenna array.

[0088] The communication manager 615 can be an example of aspects of the communication manager 515 described herein. The communication manager 615 can include a parameter component 620, a waveform component 625, an LBT component 630, and a signaling component 635. The communication manager 615 can be an example of aspects of the communication manager 810 described herein.

[0089] The parameter component 620 can identify a set of transmission parameters for a first signal to be transmitted from the wireless device. The waveform component 625 can generate a first transmission waveform of the first signal on a set of radio resources based on the set of transmission parameters for transmission from the wireless device. The LBT component 630 can perform LBT using the generated first transmission waveform. The signaling component 635 can send a second signal based on the set of transmission parameters and the result of the LBT.

[0090] The transmitter 640 can send signals generated by other components of the device 605. In some examples, the transmitter 640 can be co-located with the receiver 610 in a transceiver module. For example, the transmitter 640 can be an example of aspects of the transceiver 820 described with reference to Figure 8 The transmitter 640 can use a single antenna or an antenna array.

[0091] Figure 7 FIG. 700 is a block diagram showing a communication manager 705 that supports techniques for an LBT access mechanism for a radar system, in accordance with various aspects of the present disclosure. The communication manager 705 can be an example of aspects of the communication manager 515, the communication manager 615, or the communication manager 810 described herein. The communication manager 705 can include a parameter component 710, a waveform component 715, an LBT component 720, a signaling component 725, a signal processing component 730, a measurement component 735, a channel sensing component 740, a signal detection component 745, and a configuration component 750. Each of these modules can communicate with each other directly or indirectly (e.g., via one or more buses).

[0092] The parameter component 710 can identify a set of transmission parameters for a first signal transmitted from a wireless device. In some examples, the parameter component 710 can identify a second set of transmission parameters for a first signal from the wireless device. In some examples, the parameter component 710 can select one or more transmission parameters based on the comparison. In some examples, the parameter component 710 can determine that one or more transmission parameters correspond to a measurement result that is the minimum in a set of measurement results, wherein the selection of the one or more transmission parameters is based on the determination. In some cases, the wireless device includes a vehicle.

[0093] The waveform component 715 can generate a first transmission waveform of the first signal on a set of radio resources based on the set of transmission parameters for transmission from the wireless device. In some examples, the waveform component 715 can generate a second transmission waveform according to the second set of transmission parameters.

[0094] The LBT component 720 can use the generated first transmission waveform to perform LBT. In some examples, the LBT component 720 can perform LBT including: adjusting the detected signal associated with the set of radio resources based on the first transmission waveform. In some examples, the LBT component 720 can identify the result of LBT based on a measurement result that meets the threshold.

[0095] In some examples, the LBT component 720 can use the generated second transmission waveform to perform a second LBT, wherein performing the second LBT includes adjusting the detected signal associated with the set of resources based on the second transmission waveform.

[0096] The signaling component 725 can send a second signal based on the result of LBT, the set of transmission parameters, or a combination thereof. In some examples, the signaling component 725 can use the first transmission waveform to send the second signal. In some examples, the signaling component 725 can use the second transmission waveform to send the second signal based on the successful result of the second LBT. In some examples, the signaling component 725 can send the second signal according to the selected one or more transmission parameters. In some examples, the signaling component 725 can send a frequency modulated continuous wave radar signal.

[0097] The signal processing component 730 can process the detected signal and the first transmission waveform to obtain a measurement result.

[0098] The measurement component 735 may compare the measurement result of the LBT with a set of measurement results associated with the LBT set. In some examples, the LBT component 720 may determine that the measurement result meets the threshold. In some cases, the measurement result is less than the threshold, and the result of the LBT includes a successful result. In some cases, the measurement result is greater than or equal to the threshold, and the result of the LBT includes a failed result. In some cases, the set of transmission parameters is the last set of transmission parameters in the set of sets of transmission parameters.

[0099] The channel sensing component 740 may sense a channel associated with a set of radio resources during a first time period.

[0100] The signal detection component 745 may identify a detected signal based on the sensed channel, wherein performing the LBT is based on the detected signal.

[0101] The configuration component 750 may identify the first time period based on the configuration of the wireless device, information received from another wireless device, a confidence threshold, or any combination thereof.

[0102] Figure 8 FIG. shows a system 800 including an apparatus 805 that incorporates techniques to support an LBT access mechanism for a radar system, in accordance with various aspects of the present disclosure. The apparatus 805 may be an example of, or include components of, the apparatus 505, apparatus 605, or a wireless device (e.g., a UE 115 such as a vehicle) described herein. The apparatus 805 may include components for two-way voice and data communication, including components for sending and receiving communications, including a communication manager 810, an I / O controller 815, a transceiver 820, an antenna 825, a memory 830, and a processor 840. These components may communicate electronically via one or more buses (e.g., bus 845).

[0103] The communication manager 810 may generate a first transmission waveform of a first signal on a set of radio resources based on a set of transmission parameters for a transmission from the wireless device; perform an LBT using the generated first transmission waveform; and transmit the signal based on the set of transmission parameters and the result of the LBT.

[0104] The I / O controller 815 may manage the input and output signals of the apparatus 805. The I / O controller 815 may also manage peripheral devices not integrated into the apparatus 805. In some cases, the I / O controller 815 may represent a physical connection or port to an external peripheral device. In some cases, the I / O controller 815 may use, such as an operating system or other known operating systems. In other cases, the I / O controller 815 can represent or interact with a modem, keyboard, mouse, touch screen, or similar device. In some cases, the I / O controller 815 can be implemented as part of a processor. In some cases, a user can interact with the device 805 via the I / O controller 815 or via a hardware component controlled by the I / O controller 815.

[0105] As described herein, the transceiver 820 can communicate bidirectionally via one or more antennas, wired or wireless links. For example, the transceiver 820 can represent a wireless transceiver and can communicate bidirectionally with another wireless transceiver. The transceiver 820 can also include a modem that modulates packets and provides the modulated packets to the antenna for transmission, and demodulates packets received from the antenna.

[0106] In some cases, the wireless device can include a single antenna 825. However, in some cases, the device can have more than one antenna 825, which can be capable of simultaneously transmitting or receiving multiple wireless transmissions.

[0107] The memory 830 can include random access memory (RAM) and read-only memory (ROM). The memory 830 can store computer-readable, computer-executable code 835 that includes instructions that, when executed, cause the processor to perform the various functions described herein. In some cases, among other things, the memory 830 can contain a basic input / output system (BIOS) that can control basic hardware or software operations, such as interactions with peripheral components or devices.

[0108] The processor 840 can include intelligent hardware devices (e.g., general-purpose processors, DSPs, CPUs, microcontrollers, ASICs, FPGAs, programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or any combination thereof). In some cases, the processor 840 can be configured to operate a memory array using a memory controller. In other cases, the memory controller can be integrated into the processor 840. The processor 840 can be configured to execute computer-readable instructions stored in a memory (e.g., the memory 830) to cause the device 805 to perform various functions (e.g., functions or tasks supporting techniques for a LBT access mechanism for a radar system).

[0109] Code 835 may include instructions for implementing aspects of the present disclosure, including instructions for supporting wireless communications. Code 835 may be stored in a non-transitory computer-readable medium such as system memory or other types of memory. In some cases, Code 835 may not be directly executable by the processor 840, but may cause a computer (e.g., when compiled and executed) to perform the functions described herein.

[0110] Figure 9 A flowchart of a method 900 is shown that illustrates techniques for supporting an LBT access mechanism for a radar system in accordance with various aspects of the present disclosure. Operations of method 900 may be implemented by a wireless device (e.g., UE 115 such as a vehicle) described herein or components thereof. For example, operations of method 900 may be performed by a communication manager as described with reference to Figures 5 to 8 In some examples, the wireless device may execute an instruction set to control functional units of the wireless device to perform the functions described herein. Additionally or alternatively, the wireless device may perform aspects of the functions described herein using dedicated hardware.

[0111] At 905, the wireless device may generate a first transmission waveform of a first signal over a radio resource set based on a set of transmission parameters for transmission from the wireless device. The operation of 905 may be performed according to methods described herein. In some examples, some aspects of the operation of 905 may be performed by a waveform component as described with reference to Figures 5 to 8 In some examples, some aspects of the operation of 905 may be performed by a waveform component as described with reference to

[0112] At 910, the wireless device may perform LBT using the generated first transmission waveform. The operation of 910 may be performed according to methods described herein. In some examples, some aspects of the operation of 910 may be performed by an LBT component as described with reference to Figures 5 to 8 In some examples, some aspects of the operation of 910 may be performed by an LBT component as described with reference to

[0113] At 915, the wireless device may transmit a second signal based on the set of transmission parameters and the result of the LBT. The operation of 915 may be performed according to methods described herein. In some examples, some aspects of the operation of 915 may be performed by a signaling component as described with reference to Figures 5 to 8 In some examples, some aspects of the operation of 915 may be performed by a signaling component as described with reference to

[0114] Figure 10 A flowchart of a method 1000 is shown that illustrates techniques for supporting an LBT access mechanism for a radar system in accordance with various aspects of the present disclosure. Operations of method 1000 may be implemented by a wireless device (e.g., UE 115 such as a vehicle) described herein or components thereof. For example, operations of method 1000 may be performed by a communication manager as described with reference to Figures 5 to 8Performed by the described communication manager. In some examples, the wireless device may execute an instruction set to control the functional units of the wireless device to perform the functions described herein. Additionally or alternatively, the wireless device may perform aspects of the functions described herein using dedicated hardware.

[0115] At 1005, the wireless device may generate a first transmission waveform of a first signal on a radio resource set based on a set of transmission parameters for a transmission from the wireless device. The operation of 1005 may be performed according to the methods described herein. In some examples, some aspects of the operation of 1005 may be performed by a waveform component as described with reference to Figures 5 to 8 The described waveform component.

[0116] At 1010, the wireless device may perform LBT using the generated first transmission waveform, where LBT includes adjusting a detected signal associated with the radio resource set based on the first transmission waveform. The operation of 1010 may be performed according to the methods described herein. In some examples, some aspects of the operation of 1010 may be performed by an LBT component as described with reference to Figures 5 to 8 The described LBT component.

[0117] At 1015, the wireless device may send a second signal based on the set of transmission parameters and the result of the LBT. The operation of 1015 may be performed according to the methods described herein. In some examples, some aspects of the operation of 1015 may be performed by a signaling component as described with reference to Figures 5 to 8 The described signaling component.

[0118] It should be noted that: the methods described herein describe possible implementations, and the operations and steps may be rearranged or otherwise modified, and other implementations are possible. Additionally, aspects from two or more of these methods may be combined.

[0119] The following provides an overview of aspects of the present disclosure:

[0120] Aspect 1: A method for wireless communication at a wireless device, including: generating a first transmission waveform of a first signal on a radio resource set at least in part based on a set of transmission parameters for a transmission from the wireless device; performing LBT using the generated first transmission waveform; and sending a second signal at least in part based on the set of transmission parameters and the result of the LBT.

[0121] Aspect 2: The method according to aspect 1, wherein performing the LBT includes: adjusting a detected signal associated with the radio resource set at least in part based on the first transmission waveform.

[0122] Aspect 3: The method according to any one of Aspects 1 to 2 further includes: processing the detected signal and the first transmission waveform to obtain a measurement result; determining that the measurement result meets a threshold; and identifying the result of the LBT at least in part based on the measurement result that meets the threshold.

[0123] Aspect 4: The method according to Aspect 3, wherein the measurement result is less than the threshold, and the result of the LBT includes a successful result.

[0124] Aspect 5: The method according to any one of Aspects 3 to 4, wherein the measurement result is greater than or equal to the threshold, and the result of the LBT includes a failed result.

[0125] Aspect 6: The method according to any one of Aspects 1 to 5, wherein the result of the LBT is a successful result, further includes: using the first transmission waveform to transmit the second signal.

[0126] Aspect 7: The method according to any one of Aspects 1 to 6, wherein the result of the LBT is a failed result, further includes: identifying a second set of transmission parameters of the first signal from the wireless device; generating a second transmission waveform according to the second set of transmission parameters; performing a second LBT at least in part based on generating the second transmission waveform, wherein performing the second LBT includes: adjusting the detected signal associated with the radio resource set at least in part based on the second transmission waveform; and using the second transmission waveform to transmit the second signal at least in part based on a successful result of the second LBT.

[0127] Aspect 8: The method according to any one of Aspects 1 to 7, wherein the result of the LBT is a failed result, further includes: comparing the measurement result of the LBT with a set of measurement results associated with an LBT set; selecting one or more transmission parameters at least in part based on the comparison; and transmitting the second signal according to the selected one or more transmission parameters.

[0128] Aspect 9: The method according to Aspect 8 further includes: determining that the one or more transmission parameters correspond to a measurement result that is the minimum value in the set of measurement results, wherein the selection of the one or more transmission parameters is at least in part based on the determination.

[0129] Aspect 10: The method according to any one of Aspects 8 to 9, wherein the set of transmission parameters is the last set of transmission parameters in a plurality of sets of transmission parameters.

[0130] Aspect 11: The method according to any one of Aspects 1 to 10, wherein performing the LBT includes: sensing a channel associated with the radio resource set during a first time period; and identifying a detected signal at least in part based on sensing the channel, wherein performing the LBT is at least in part based on the detected signal.

[0131] Aspect 12: The method according to Aspect 11, further comprising: identifying the first time period at least in part based on a configuration of the wireless device, information received from another wireless device, a confidence threshold, or any combination thereof.

[0132] Aspect 13: The method according to any one of Aspects 1 to 12, wherein transmitting the second signal includes: transmitting a frequency modulated continuous wave radar signal.

[0133] Aspect 14: The method according to any one of Aspects 1 to 13, wherein the wireless device includes a vehicle.

[0134] Aspect 15: An apparatus for wireless communication at a wireless device, comprising a processor, a memory coupled to the processor, and instructions stored in the memory and executable by the processor to cause the apparatus to perform the method according to any one of Aspects 1 to 14.

[0135] Aspect 16: An apparatus for wireless communication at a wireless device, comprising at least one unit for performing the method according to any one of Aspects 1 to 14.

[0136] Aspect 17: A non-transitory computer-readable medium storing code for wireless communication at a wireless device, the code including instructions executable by a processor to perform the method according to any one of Aspects 1 to 14.

[0137] Although some aspects of LTE, LTE-A, LTE-A Pro, or NR systems may be described for example purposes, and LTE, LTE-A, LTE-A Pro, or NR terminology may be used in most of the description, the techniques described herein can be applied outside of LTE, LTE-A, LTE-A Pro, or NR networks. For example, the described techniques can be applicable to various other wireless communication systems such as Ultra Mobile Broadband (UMB), Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM, and other systems and radio technologies not explicitly mentioned herein.

[0138] Any of a variety of different techniques and methods can be used to represent the information and signals described herein. For example, the data, instructions, commands, information, signals, bits, symbols, and chips referred to throughout this specification can be represented by voltages, currents, electromagnetic waves, magnetic fields or magnetic particles, optical fields or optical particles, or any combination thereof.

[0139] The various illustrative blocks and components described in connection with the disclosure herein can be implemented or performed using a general purpose processor, DSP, ASIC, CPU, FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof. The general purpose processor can be a microprocessor, but in the alternative, the processor can be any processor, controller, microcontroller, or state machine. The processor can also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such architecture).

[0140] The functions described herein can be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions can be stored on or transmitted via a computer-readable medium as one or more instructions or code. Other examples and implementations are within the scope of the present application and the appended claims. For example, due to the nature of software, the functions described herein can be implemented using software executed by a processor, hardware, firmware, hardwiring, or any combination thereof. The features implementing the functions can also be physically located in various positions, including being distributed such that portions of the functions are implemented at different physical locations.

[0141] A computer-readable medium includes both a non-transitory computer storage medium and a communication medium, where the communication medium includes any medium that facilitates transfer of a computer program from one location to another. The non-transitory storage medium can be any available medium that can be accessed by a general purpose or special purpose computer. By way of example, and not limitation, non-transitory computer-readable media can include RAM, ROM, electrically erasable programmable ROM (EEPROM), flash memory, compact disc (CD) ROM or other optical disc storage, magnetic disk storage or other magnetic storage devices, or any other non-transitory medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a general purpose or special purpose computer or a general purpose or special purpose processor. In addition, any connection can be properly termed a computer-readable medium. For example, if software is transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of computer-readable medium. As used herein, disk and disc include CD, laser disc, optical disc, digital versatile disc (DVD), floppy disk, and Blu-ray disc, where disks typically reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media.

[0142] As used herein, and as included in the claims, the term "or" as used in a list of items (e.g., in a list of items prefaced by a phrase such as "at least one of" or "one or more of") indicates an inclusive list, such that, for example, a list of at least one of A, B, or C means A, or B, or C, or AB, or AC, or BC, or ABC (i.e., A and B and C). Additionally, as used herein, the phrase "based on" should not be construed as a reference to a closed set of conditions. For example, a step described as "based on condition A" can be based on both condition A and condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase "based on" will be interpreted in the same manner as the phrase "at least partially based on".

[0143] In the figures, similar components or features may have the same reference numerals. Additionally, each of the same type of components can be distinguished by following the reference numeral with a dash and a second numeral used to differentiate among similar components. If only the first reference numeral is used in this specification, then the description applies to any one of the similar components having the same first reference numeral, regardless of the second reference numeral or any other subsequent reference numerals.

[0144] The specification set forth in conjunction with the accompanying drawings describes example configurations and does not represent all examples that can be implemented or that are within the scope of the claims. The term "example" as used throughout this specification means "serving as an example, instance, or illustration" and not "preferred" or "advantageous" as compared to other examples. To provide an understanding of the described technology, the detailed description includes specific details. However, the technology may be practiced without these specific details. In some instances, well-known structures and devices are shown in block diagram form in order to avoid obscuring the concepts of the described examples.

[0145] The description herein is provided to enable a person of ordinary skill in the art to make or use the disclosed subject matter. Various modifications to this disclosure will be apparent to those of skill in the art, and the general principles defined herein may be applied to other variations without departing from the scope of this disclosure. Thus, this disclosure is not limited to the examples and designs described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for wireless communication at a wireless device, comprising: generating a first transmission waveform of a first signal over a radio resource set, at least in part based on a set of transmission parameters for transmission from the wireless device; identifying, during a first time period, the received energy of a detected signal associated with the radio resource set of the channel; adjusting the received energy of the detected signal based on the first transmission waveform; determining a measurement of interference between the first signal and the detected signal, at least in part based on the adjusted received energy; and transmitting a second signal, at least in part based on the set of transmission parameters and the measurement of interference.

2. The method according to claim 1, wherein: adjusting the received energy based on the first transmission waveform includes mixing the received energy with the generated first transmission waveform.

3. The method according to claim 1, further comprising: determining that the measurement meets a threshold.

4. The method according to claim 3, wherein The measurement is less than the threshold.

5. The method according to claim 3, wherein, The measurement is greater than or equal to the threshold.

6. The method according to claim 4, further comprising: transmitting the second signal using the first transmission waveform.

7. The method according to claim 5, further comprising: identifying a second set of transmission parameters for the first signal from the wireless device; generating a second transmission waveform according to the second set of transmission parameters; determining a second measurement, based at least in part on adjusting the received energy based on the second transmission waveform; and transmitting the second signal using the second transmission waveform, at least in part based on the second measurement meeting the threshold.

8. The method according to claim 1, further comprising: comparing the measurement with a set of measurements associated with a set of transmission waveforms; selecting one or more transmission parameters, at least in part based on the comparison; and transmitting the second signal according to the selected one or more transmission parameters.

9. The method according to claim 8, further comprising: determining that the one or more transmission parameters correspond to a measurement that is the minimum value in the set of measurements, wherein the selection of the one or more transmission parameters is at least in part based on the determination.

10. The method according to claim 8, wherein The set of transmission parameters is the last set of transmission parameters in a plurality of sets of transmission parameters.

11. The method according to claim 1, further comprising: identifying the first time period, at least in part based on the configuration of the wireless device, information received from another wireless device, a confidence threshold, or any combination thereof.

12. The method according to claim 1, wherein Transmitting the second signal includes: transmitting a frequency modulated continuous wave radar signal.

13. The method according to claim 1, wherein, The wireless device includes a vehicle.

14. An apparatus for wireless communication at a wireless device, comprising: a unit for generating a first transmission waveform of a first signal over a radio resource set, at least in part based on a set of transmission parameters for transmission from the wireless device; a unit for identifying, during a first time period, the received energy of a detected signal associated with the radio resource set of the channel; A unit for adjusting the received energy of the detected signal based on the first transmission waveform; A unit for determining a measurement result of interference between the first signal and the detected signal based at least in part on the adjusted received energy; And A unit for transmitting a second signal based at least in part on the set of transmission parameters and the measurement result of the interference.

15. An apparatus for wireless communication at a wireless device, comprising: A processor, A memory coupled to the processor; And Instructions stored in the memory and executable by the processor to cause the apparatus to perform the following operations: Generate a first transmission waveform of a first signal on a set of radio resources based at least in part on a set of transmission parameters for transmission from the wireless device; Identify the received energy of a detected signal associated with the set of radio resources of the channel during a first time period; Adjust the received energy of the detected signal based on the first transmission waveform; Determine a measurement result of interference between the first signal and the detected signal based at least in part on the adjusted received energy; And Transmit a second signal based at least in part on the set of transmission parameters and the measurement result of the interference.

16. The apparatus according to claim 15, wherein: Adjusting the received energy based on the first transmission waveform includes mixing the received energy with the generated first transmission waveform.

17. The apparatus according to claim 15, wherein The instructions are further executable by the processor to cause the apparatus to perform the following operations: Determine that the measurement result meets a threshold.

18. The apparatus according to claim 17, wherein The measurement result is less than the threshold.

19. The apparatus according to claim 17, wherein The measurement result is greater than or equal to the threshold.

20. The apparatus according to claim 18, wherein, The instructions are further executable by the processor to cause the apparatus to perform the following operations: Use the first transmission waveform to transmit the second signal.

21. The apparatus according to claim 19, wherein The instructions are further executable by the processor to cause the apparatus to perform the following operations: Identify a second set of transmission parameters for the first signal from the wireless device; Generate a second transmission waveform according to the second set of transmission parameters; Determine a second measurement result based at least in part on adjusting the received energy based on the second transmission waveform; And Transmit the second signal using the second transmission waveform based at least in part on the second measurement result meeting the threshold.

22. The device according to claim 15, wherein The instructions are further executable by the processor to cause the apparatus to perform the following operations: Compare the measurement result with a set of measurement results associated with a set of transmission waveforms; Select one or more transmission parameters based at least in part on the comparison; And Transmit the second signal according to the selected one or more transmission parameters.

23. The device according to claim 22, wherein, The instructions are further executable by the processor to cause the apparatus to perform the following operations: Determine that the one or more transmission parameters correspond to a measurement result that is the minimum value in the set of measurement results, wherein the selection of the one or more transmission parameters is based at least in part on the determination.

24. The apparatus according to claim 22, wherein, The set of transmission parameters is the last set of transmission parameters in a plurality of sets of transmission parameters.

25. The device according to claim 15, wherein The instructions may also be executed by the processor to cause the apparatus to perform the following operations: Identify the first time period based at least in part on the configuration of the wireless device, information received from another wireless device, a confidence threshold, or any combination thereof.

26. The device according to claim 15, wherein, The instructions may also be executed by the processor to cause the apparatus to perform the following operations: Transmit a frequency-modulated continuous-wave radar signal.

27. The device according to claim 15, wherein, The wireless device includes a vehicle.

28. A non-transitory computer-readable medium storing code for wireless communication at a wireless device, the code including instructions executable by a processor to perform the following operations: Generate a first transmission waveform of a first signal on a radio resource set based at least in part on a set of transmission parameters for transmission from the wireless device; Identify received energy of a detected signal associated with the radio resource set of the channel during a first time period; Adjust the received energy of the detected signal based on the first transmission waveform; Determine a measurement of interference between the first signal and the detected signal based at least in part on the adjusted received energy; and Transmit a second signal based at least in part on the set of transmission parameters and the measurement of interference.

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