Patent Description:
A wireless multiple-access communications system may include a number of base stations or access network nodes, each simultaneously supporting communication for multiple communication devices, that may be otherwise known as user equipment (UE).

<CIT> relates to an enhanced preamble waveform for co-existence of multiple radio access technologies (RATs) over a shared frequency band. <CIT> relates to superposition coding based preamble designs for co-existing radio access technologies. <CIT> relates to techniques of interference determination using adaptive energy detection. <CIT> relates to an inter-terminal direct communication scheme in a multi-frequency network. <CIT> relates to a method, an apparatus, and a system for band sharing.

Wireless communication systems may include or support networks used for vehicle based communications, also referred to as V2X, vehicle-to-vehicle (V2V) networks, cellular V2X (C-V2X) networks, or other similar networks. Vehicle based communication networks may provide always on telematics where UEs, e.g., vehicle UEs (v-UEs), communicate directly to the network (V2N), to pedestrian UEs (V2P), to infrastructure devices (V2I), and to other v-UEs (e.g., via the network and/or directly). The vehicle based communication networks may support a safe, always-connected driving experience by providing intelligent connectivity where traffic signal/timing, real-time traffic and routing, safety alerts to pedestrians/bicyclist, collision avoidance information, etc., are exchanged.

In some examples, the communications in vehicle based networks may include safety message transmissions (e.g., basic safety message (BSM) transmissions). Such BSM transmissions may use a radio frequency spectrum band that is split into BSM sub-bands and non-BSM sub-bands. In some instances, the sub-bands may be shared between next generation wireless devices (e.g., <NUM> UEs, <NUM> v-UEs, etc.) and legacy devices and/or devices operating using different radio access technologies (RATs) or protocols. For example, the <NUM> devices may share a BSM sub-band and/or non-BSM sub-band with Wi-Fi devices and/or other devices configured for other cellular technologies (e.g., Multi-Fire RAT, licensed access assist, etc.). Sharing of the BSM and/or non-BSM sub-bands may, in some aspects, create conflicts related to resource selection and usage, priorities for safety messages vs non-safety related messages, and the like.

The invention made is disclosed in the embodiments related to <FIG>. Aspects of the described techniques may provide for resource selection by <NUM> devices and/or prioritized sharing of a shared radio frequency spectrum band. Certain radio frequency spectrum bands may be split and used for different purposes. As one example, an intelligent transport services (ITS) band may be split into a basic safety message (BSM) band and a non-BSM band (or channels). The BSM and the non-BSM channels may each have their own associated tine spacing, transmission opportunity (TxOP), bandwidth characteristics, and the like. In some examples, the BSM and/or non-BSM channels may be a radio frequency spectrum band that is shared between legacy devices (e.g., Wi-Fi devices, MultiFire devices, etc.) and next generation devices (e.g., <NUM> cellular vehicle-to-everything (<NUM> C-V2X) devices). The <NUM> devices may use the BSM and, in some examples, the non-BSM channels for wireless transmissions of safety messages that are unicast and/or broadcast transmissions.

Aspects of the disclosure are initially described in the context of a wireless communications system, such as a vehicle based wireless network. In some aspects, a <NUM> device may select resource blocks to use for wireless transmissions by listening to control channel transmissions of legacy devices to identify available resource blocks (RBs). For example, the <NUM> device may decode control channel transmissions for safety messages transmitted on the shared band. The control channel transmissions may be decoded during a first portion of a time period (e.g., the first one, two, three, etc. symbol periods) and may include an indication of which time-frequency resources (e.g., resource blocks) the transmitting legacy device is using for transmission. Based on the decoded control channel(s), the <NUM> may identify which resource blocks are available for a second portion of the time period (e.g., the remaining symbol periods of the slot, subframe, frame, etc.), that may form a pool of available resource blocks. The <NUM> device may select a subset of resource blocks from the pool of available resource blocks to use for transmission during the second portion of the time period, e.g., a sufficient number of resource blocks to transmit the buffered information.

In some aspects, the <NUM> device may provide for prioritized sharing by using a preamble configured for the legacy devices to reserve the resource(s) of the channel(s) for the <NUM> device. For example, the <NUM> device may be configured to communicate using an advanced radio access technology (RAT), e.g., a first RAT. The <NUM> device may identify or otherwise determine that the band is being shared with legacy devices configured to operating using a second RAT. The <NUM> device may generate and transmit a preamble that is decodable by the legacy devices using the second RAT (e.g., a legacy preamble) that carries or otherwise conveys an indication of a transmission by the <NUM> device using the first RAT. The preamble may be decoded by the legacy devices, that serves to prevent the legacy devices from using the resources reserved by the <NUM> device.

In some aspects, the legacy device may support prioritized sharing by adopting a shorter TxOP when operating on a channel that is shared by <NUM> device(s). For example, the legacy device may identify or otherwise determine that the radio frequency spectrum band is shared with <NUM> devices (e.g., devices configured for the first RAT). The legacy device may identify the TxOP for the second RAT and select a shorter (or smaller) TxOP duration for communications on the shared band. The shorter TxOP may provide for an increased number of opportunities for the <NUM> device to capture the shared band.

Aspects of the disclosure are further illustrated by and described with reference to apparatus diagrams, system diagrams, and flowcharts that relate to <NUM> cellular V2X design principles.

<FIG> illustrates an example of a wireless communication system <NUM> in accordance with various aspects of the present disclosure. The wireless communication system <NUM> includes base stations <NUM>, UEs <NUM>, and a core network <NUM>. In some examples, the wireless communications system <NUM> may be a Long Term Evolution (LTE), LTE-Advanced (LTE-A) network, or a 5th Generation (<NUM>)/New Radio (NR) network. In some cases, wireless communications system <NUM> may support enhanced broadband communications, ultra-reliable (i.e., mission critical) communications, low latency communications, and communications with low-cost and low-complexity devices.

Each base station <NUM> may provide communication coverage for a respective geographic coverage area <NUM>. Communication links <NUM> shown in wireless communication system <NUM> may include uplink transmissions from a UE <NUM> to a base station <NUM>, or downlink transmissions, from a base station <NUM> to a UE <NUM>. Control information and data may be multiplexed on an uplink channel or a downlink channel according to various techniques. Control information and data may be multiplexed on a downlink channel, for example, using time division multiplexing (TDM) techniques, frequency division multiplexing (FDM) techniques, or hybrid TDM-FDM techniques. In some examples, the control information transmitted during a transmission time interval (TTI) of a downlink channel may be distributed between different control regions in a cascaded manner (e.g., between a common control region and one or more UE-specific control regions).

UEs <NUM> may be dispersed throughout the wireless communication system <NUM>, and each UE <NUM> may be stationary or mobile. A UE <NUM> may also be referred to as a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communications device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, a client, or some other suitable terminology. A UE <NUM> may also be a cellular phone, a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a tablet computer, a laptop computer, a cordless phone, a personal electronic device, a handheld device, a personal computer, a wireless local loop (WLL) station, an Internet of Things (IoT) device, an Internet of Everything (IoE) device, a machine type communication (MTC) device, an appliance, an automobile, or the like.

In some cases, groups of UEs <NUM> communicating via D2D communications may utilize a one-to-many (<NUM>:M) system in that each UE <NUM> transmits to every other UE <NUM> in the group. Another example of direct UE-<NUM> communications may include V2X and/or V2V communications. Thus, references to a vehicle may refer to a UE <NUM> where the vehicle is equipped to perform wireless communications using the described techniques.

In some cases, an MTC device may operate using half-duplex (one-way) communications at a reduced peak rate. MTC devices may also be configured to enter a power saving "deep sleep" mode when not engaging in active communications. In some cases, MTC or IoT devices may be designed to support mission critical functions and wireless communications system may be configured to provide ultra-reliable communications for these functions.

The core network may be an evolved packet core (EPC), that may include at least one mobility management entity (MME), at least one serving gateway (S-GW), and at least one Packet Data Network (PDN) gateway (P-GW). All user Internet Protocol (IP) packets may be transferred through the S-GW, that itself may be connected to the P-GW.

The core network <NUM> may provide user authentication, access authorization, tracking, IP connectivity, and other access, routing, or mobility functions. At least some of the network devices, such as base station <NUM> may include subcomponents such as an access network entity, that may be an example of an access node controller (ANC). Each access network entity may communicate with a number of UEs <NUM> through a number of other access network transmission entities, each of which may be an example of a smart radio head, or a transmission/reception point (TRP).

Wireless communication system <NUM> may operate in an ultra-high frequency (UHF) frequency region using frequency bands from <NUM> to <NUM> (<NUM>), although some networks (e.g., a wireless local area network (WLAN)) may use frequencies as high as <NUM>. This region may also be known as the decimeter band, since the wavelengths range from approximately one decimeter to one meter in length. UHF waves may propagate mainly by line of sight, and may be blocked by buildings and environmental features. However, the waves may penetrate walls sufficiently to provide service to UEs <NUM> located indoors. Transmission of UHF waves is characterized by smaller antennas and shorter range (e.g., less than <NUM>) compared to transmission using the smaller frequencies (and longer waves) of the high frequency (HF) or very high frequency (VHF) portion of the spectrum. In some cases, wireless communication system <NUM> may also utilize extremely high frequency (EHF) portions of the spectrum (e.g., from <NUM> to <NUM>). This region may also be known as the millimeter band, since the wavelengths range from approximately one millimeter to one centimeter in length. Thus, EHF antennas may be even smaller and more closely spaced than UHF antennas. In some cases, this may facilitate use of antenna arrays within a UE <NUM> (e.g., for directional beamforming). However, EHF transmissions may be subject to even greater atmospheric attenuation and shorter range than UHF transmissions.

Thus, wireless communication system <NUM> may support millimeter wave (mmW) communications between UEs <NUM> and base stations <NUM>. Devices operating in mmW or EHF bands may have multiple antennas to allow beamforming. That is, a base station <NUM> may use multiple antennas or antenna arrays to conduct beamforming operations for directional communications with a UE <NUM>. Beamforming (that may also be referred to as spatial filtering or directional transmission) is a signal processing technique that may be used at a transmitter (e.g., a base station <NUM>) to shape and/or steer an overall antenna beam in the direction of a target receiver (e.g., a UE <NUM>). This may be achieved by combining elements in an antenna array in such a way that transmitted signals at particular angles experience constructive interference while others experience destructive interference.

In some cases, the antennas of a base station <NUM> or UE <NUM> may be located within one or more antenna arrays, that may support beamforming or multiple-input/multiple-output (MIMO) operations. One or more base station antennas or antenna arrays may be collocated at an antenna assembly, such as an antenna tower. A base station <NUM> may multiple use antennas or antenna arrays to conduct beamforming operations for directional communications with a UE <NUM>.

In some cases, wireless communication system <NUM> may be a packet-based network that operate according to a layered protocol stack. The MAC layer may also use Hybrid ARQ (HARQ) to provide retransmission at the MAC layer to improve link efficiency.

Time intervals in LTE or NR may be expressed in multiples of a basic time unit. Time resources may be organized according to radio frames of length of <NUM>, that may be identified by a system frame number (SFN) ranging from <NUM> to <NUM>. Each frame may include ten <NUM> subframes numbered from <NUM> to <NUM>. A subframe may be further divided into two. <NUM> slots, each of which contains <NUM> or <NUM> modulation symbol periods (depending on the length of the cyclic prefix prepended to each symbol). Excluding the cyclic prefix, each symbol contains <NUM> sample periods. In some cases the subframe may be the smallest scheduling unit, also known as a TTI. In other cases, a TTI may be shorter than a subframe or may be dynamically selected (e.g., in short TTI bursts or in selected component carriers using short TTIs).

A resource element may consist of one symbol period and one subcarrier (e.g., a <NUM> frequency range). A resource block may contain <NUM> consecutive subcarriers in the frequency domain and, for a normal cyclic prefix in each OFDM symbol, <NUM> consecutive OFDM symbols in the time domain (<NUM> slot), or <NUM> resource elements. The number of bits carried by each resource element may depend on the modulation scheme (the configuration of symbols that may be selected during each symbol period). Thus, the more resource blocks that a UE receives and the higher the modulation scheme, the higher the data rate may be.

Wireless communication system <NUM> may support operation on multiple cells or carriers, a feature that may be referred to as carrier aggregation (CA) or multi-carrier operation. A carrier may also be referred to as a component carrier (CC), a layer, a channel, etc. The terms "carrier," "component carrier," "cell," and "channel" may be used interchangeably herein. A UE <NUM> may be configured with multiple downlink CCs and one or more uplink CCs for carrier aggregation.

In some cases, wireless communication system <NUM> may utilize enhanced component carriers (eCCs). An eCC may be characterized by one or more features including: wider bandwidth, shorter symbol duration, shorter TTIs, and modified control channel configuration. An eCC may also be configured for use in unlicensed spectrum or shared spectrum (where more than one operator is allowed to use the spectrum). An eCC characterized by wide bandwidth may include one or more segments that may be utilized by UEs <NUM> that are not capable of monitoring the whole bandwidth or prefer to use a limited bandwidth (e.g., to conserve power).

In some cases, an eCC may utilize a different symbol duration than other CCs, that may include use of a reduced symbol duration as compared with symbol durations of the other CCs. A shorter symbol duration is associated with increased subcarrier spacing. A device, such as a UE <NUM> or base station <NUM>, utilizing eCCs may transmit wideband signals (e.g., <NUM>, <NUM>, <NUM>, <NUM>, etc.) at reduced symbol durations (e.g., <NUM> microseconds). A TTI in eCC may consist of one or multiple symbols. In some cases, the TTI duration (that is, the number of symbols in a TTI) may be variable.

A shared radio frequency spectrum band may be utilized in an NR shared spectrum system. For example, an NR shared spectrum may utilize any combination of licensed, shared, and unlicensed spectrums, among others. The flexibility of eCC symbol duration and subcarrier spacing may allow for the use of eCC across multiple spectrums. In some examples, NR shared spectrum may increase spectrum utilization and spectral efficiency, specifically through dynamic vertical (e.g., across frequency) and horizontal (e.g., across time) sharing of resources.

In some cases, wireless communication system <NUM> may utilize both licensed and unlicensed radio frequency spectrum bands. For example, wireless communication system <NUM> may employ LTE License Assisted Access (LTE-LAA) or LTE Unlicensed (LTE U) radio access technology or NR technology in an unlicensed band such as the <NUM> Industrial, Scientific, and Medical (ISM) band. When operating in unlicensed radio frequency spectrum bands, wireless devices such as base stations <NUM> and UEs <NUM> may employ listen-before-talk (LBT) procedures to ensure the channel is clear before transmitting data. In some cases, operations in unlicensed bands may be based on a CA configuration in conjunction with CCs operating in a licensed band. Operations in unlicensed spectrum may include downlink transmissions, uplink transmissions, or both. Duplexing in unlicensed spectrum may be based on frequency division duplexing (FDD), time division duplexing (TDD) or a combination of both.

Wireless communication system <NUM> may include or support networks used for vehicle based communications, also referred to as V2X, vehicle-to-vehicle (V2V) networks, and/or cellular V2X (C-V2X) networks. Vehicle based communication networks may provide always on telematics where user equipment (UE)s, e.g., v-UEs, communicate directly to the network (V2N), to pedestrian UEs (V2P), to infrastructure devices (V2I), and to other v-UEs (e.g., directly and/or via the network). The vehicle based communication networks may support a safe, always-connected driving experience by providing intelligent connectivity where traffic signal/timing, real-time traffic and routing, safety alerts to pedestrians/bicyclist, collision avoidance information, etc., are exchanged.

Wireless communication system <NUM> may support aspects of the described design principles for <NUM> NR C-V2X communications. For example, a UE <NUM>, that may be an example of a V2X device, a <NUM> NR C-V2X device, a C-V2X device, or simply a <NUM> device, may be configured to decode control channel transmissions from legacy devices to identify resources to use for wireless communications. The UE <NUM> may decode a control channel transmission of a safety message in a V2X system during a first portion of a time period. The UE <NUM> may identify, based on the decoding, a pool of resource blocks that are available for the time period. The UE <NUM> may select a subset of resource blocks from the available pool of resource blocks for a transmission during a second portion of the time period.

In some aspects, the UE <NUM> may be configured to support prioritized sharing of a shared radio frequency spectrum band. For example, the UE <NUM> may be a <NUM> device and may identify, by the UE <NUM> that is configured to communicate using a first RAT, a shared radio frequency spectrum band that is shared between the first device and a second device that is configured to communicate using a second RAT. The UE <NUM> may generate a preamble for transmission on the shared radio frequency spectrum band, the preamble configured to be decodable by the second device (e.g., a legacy device) of the second RAT and may convey an indication of a transmission by the first device using the first RAT. The UE <NUM> may transmit the configured preamble prior to the transmission using the first RAT.

In some aspects, the UE <NUM> may be a legacy device that supports prioritized sharing of a shared radio frequency spectrum band. For example, the UE <NUM> may be a Wi-Fi device, a LAA device, a MultiFire device, or some other devices configured to communicate in the second RAT. The UE <NUM> may identify a shared radio frequency spectrum band that is shared between a first device (e.g., a <NUM> device) that is configured to communicate using a first RAT and a second device that is configured to communicate using a second RAT. The UE <NUM> may identify a first TxOP duration associated with the first RAT. The UE <NUM> may select, based at least in part on the first TxOP duration, a second TxOP duration for communications on the shared radio frequency spectrum band. The second TxOP duration may be smaller (or shorter) than the first TxOP duration.

<FIG> illustrates an example of a process <NUM> that supports <NUM> cellular V2X design principles in accordance with various aspects of the present disclosure. In some examples, process <NUM> may implement aspects of wireless communication system <NUM>. Process <NUM> may include a UE <NUM> and a base station <NUM>, that may be examples of the corresponding devices described herein. The UE <NUM> may be a <NUM> device or a <NUM> C-V2X device.

Generally, process <NUM> may provide one example for opportunistic co-channel coexistence between UE <NUM> (e.g., a <NUM> C-V2X device) and legacy devices (e.g., devices configured for Wi-Fi, LAA, MultiFire, and other types of communication protocols). In some examples, the co-channel coexistence provides a mechanism where UE <NUM> may decode control channels of legacy devices before performing <NUM> C-V2X transmissions. For example, UE <NUM> may perform control channel decoding and avoid resource blocks picked by legacy devices and create a pool of available resource blocks for <NUM> transmissions. UE <NUM> may pick resource block(s) from the resource block pool for transmission during the remaining portion of the time period (e.g., using a <NUM> millisecond or some other duration time period). In some examples, process <NUM> may be performed for wireless communications in a BSM radio frequency spectrum band.

At <NUM>, UE <NUM> may decode a control channel transmission of a safety message in a V2X system during a first portion of a time period. The first portion of the time period may include the first one, two, three, etc., symbol periods of the time period (e.g., slot, subframe, frame, etc.). The safety message in the V2X system may include a message transmitted by the legacy devices on BSM channel(s). For example, in some instances UE <NUM> may monitor multiple (e.g., some or all) channels during the first portion of the time period to detect control channel transmissions from the legacy devices. Based on the monitoring, UE <NUM> may decode some or all of the detected control channel transmissions from the legacy devices.

At <NUM>, UE <NUM> may identify a pool of resource blocks that are available for the time period. For example, UE <NUM> may identify which time-frequency resources are allocated during the remaining or second portion of the time period and, in some instances, subsequent time period(s). That is, in some examples the control channel transmissions may carry or otherwise convey an indication of which time-frequency resources (e.g., resource blocks) that are allocated for wireless transmissions by the legacy devices. The indication may be carried or conveyed in a resource grant, assignment, and the like, in the control channel transmissions. The allocated resources may include resources in the current slot, in the current slot and the next slot of the subframe, in the current subframe and the next subframe, and the like. UE <NUM> may decode the control channel transmissions to determine which resource blocks are unallocated by the legacy devices and therefore available during the second or remaining portion of the time period (and subsequent time period(s) in some examples).

In some aspects, UE <NUM> may identify the pool of resource blocks that includes some or all available resource blocks that are available for transmissions. For example, UE <NUM> may identify the pool of resource blocks that includes unused resource blocks from the current time period and subsequent time period(s). In some examples, the pool of available resource blocks may include all resource blocks that are unallocated for wireless transmissions by the legacy devices.

At <NUM>, UE <NUM> may select of subset of resource blocks from the pool of available resource blocks for a transmission during a second portion of the time period (and subsequent time period(s), in some examples). The number of resource blocks in the subset of resource blocks may be selected based on the amount of traffic that UE <NUM> has stored in a buffer.

In some aspects, UE <NUM> may select the resource blocks for the subset of resource blocks based on an ordered list of the resource blocks in the pool of available resource blocks. For example, UE <NUM> may associate an identifier associated with each available resource block that is based on the detected energy levels for the corresponding channel, based on the amount of neighboring resource blocks that are allocated by the legacy devices, based on the order in which the resource block is determined available, and the like. UE <NUM> may select from the pool of available resource blocks based on the ordered list (e.g., based on the order of the identifier) of resource blocks.

In some aspects, UE <NUM> may select the resource blocks from the pool of available resource blocks based on a random selection scheme. For example, UE <NUM> may randomly pick from the pool of available resource blocks to select the subset of resource blocks. In some aspects, randomly picking the resource blocks from the pool of available resource blocks may reduce or eliminate the chance that multiple <NUM> devices may select the same resource blocks to use for <NUM> transmissions.

In some aspects, UE <NUM> may select the resource blocks from the pool of available resource blocks based on a hashing function. For example, UE <NUM> may use a hash function based on the UE <NUM> identifier and/or a resource block index to identify and select resource blocks for the subset of resource blocks.

In some aspects, UE <NUM> may select the resource blocks from the pool of available resource blocks based on any combination of the described ordered list of the resource blocks in the pool of available resource blocks, the random selection scheme, and/or on the hashing function using the UE <NUM> identifier and resource block index.

At <NUM>, the UE <NUM> may transmit a transmission to the base station <NUM>. Although the transmission is shown as being transmitted to base station <NUM>, it is to be understood that the transmission may be transmitted to other devices, such as other UEs (e.g., <NUM> C-V2X UEs and/or legacy V2X UEs). The transmission may include a unicast transmission, a broadcast transmission, or both. The transmission may be transmitted during the second portion of the time period (e.g., the remaining symbol periods of the slot) and, in some instances, in subsequent time periods (e.g., a second slot of the subframe, a subsequent subframe, a subsequent frame, and the like).

<FIG> illustrates an example of a diagram <NUM> that supports <NUM> cellular V2X design principles in accordance with various aspects of the present disclosure. In some examples, diagram <NUM> may implement aspects of wireless communication system <NUM> and/or process <NUM>. Diagram <NUM> may be implemented by a <NUM> device, such as a UE, that may be an example of the corresponding devices described herein.

Generally, diagram <NUM> may include three time periods <NUM>, illustrated as first time period <NUM>-a, second time period <NUM>-b, and third time period <NUM>-c. In some aspects, each time period <NUM> may be an example of a slot, e.g., a slot separated into fourteen (<NUM>) symbol periods. In some aspects, each time period <NUM> may be an example of a subframe and/or a frame. Diagram <NUM> may also include a number of channels, with four channels being shown by way of example only. In some examples, diagram <NUM> may be a BSM band that includes three channels with each channel supporting a <NUM> bandwidth.

Legacy devices may include Wi-Fi devices and/or cellular devices configured to communicate in other protocols (e.g., LAA, MultiFire, and the like). Such legacy devices may typically monitor a channel for a preceding time period <NUM>, that may be <NUM> milliseconds in some examples. Based on the historical monitoring, the legacy devices may select resources for wireless communications that include one or more time periods <NUM> and/or one or more channels. In the example diagram <NUM>, a first legacy device has selected a first channel to use for wireless communications and a second legacy device has selected a third channel to use for wireless communications. During a first portion of the time period <NUM>, e.g., the time between time T0 and time T1, the legacy devices may transmit a control channel transmission for the safety message in the V2X system. Thus, the first legacy device may transmit a first control channel transmission <NUM> that carries or otherwise conveys an indication that resource blocks <NUM> and <NUM> are allocated for transmissions by the first legacy device. Similarly, the second legacy device may transmit a second control channel transmission <NUM> that carries or otherwise conveys an indication that resource blocks <NUM> and <NUM> are allocated for transmissions by the second legacy device.

A UE, e.g., a <NUM> device, that may also be a <NUM> C-V2X device, may monitor the first portion of the time period <NUM> and detect the control channel transmissions <NUM> and <NUM>. The UE may decode the control channel transmissions and identify a pool of available resource blocks. The pool of available resource blocks may include any unused or otherwise unallocated resources blocks during the second portion of the time period <NUM>-a (e.g., the time between time T1 and time T2) and, in some instances, any subsequent time periods (e.g., the time periods <NUM>-b and/or <NUM>-c). Thus, in one example the pool of available resource blocks may include resource blocks <NUM> and <NUM> that occur during the second portion of the time period <NUM>-a. In other examples, the pool of available resource blocks may include some or all of the resource blocks that are unused in the subsequent time period(s) <NUM>. For example, the pool of available resource blocks may include resource blocks <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> (e.g., the unused resource blocks for the subframe when each time period <NUM> is a slot). In another examples, the pool of available resource blocks may include resource blocks <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>, e.g., all unused resource blocks.

The UE may select a subset of resource blocks from the pool of available resource blocks. For example, the UE may select the subset of resource blocks using the ordered list of resource blocks, the random selection scheme, the hashing function using the UE identifier and the resource block index, either alone or in any combination. The UE may select a sufficient number of resource blocks for the subset of resource blocks based on the amount of traffic that the UE needs to send.

Although only the first time period <NUM>-a is shown having the first portion and second portions, it is to be understood that any and/or all of the time periods <NUM> may be divided into the first and second portions. Thus, in one example the UE may detect and decode the control channel transmissions for each time period <NUM> and then use only the unused resource blocks for that particular time period <NUM> for <NUM> wireless transmissions.

<FIG> illustrates an example of a process <NUM> that supports <NUM> cellular V2X design principles in accordance with various aspects of the present disclosure. In some examples, process <NUM> may implement aspects of wireless communication system <NUM>, process <NUM>, and/or diagram <NUM>. Process <NUM> may include a <NUM> device <NUM> and a Wi-Fi device <NUM>.

Generally, the <NUM> device <NUM> and/or the Wi-Fi device <NUM> may be examples of UEs, as is described herein. More particularly, the <NUM> device <NUM> may be an example of a next generation UE, a <NUM> C-V2X device, or simply a V2X configured device. The Wi-Fi device <NUM> may be an example of a legacy device. Although process <NUM> illustrates a Wi-Fi device <NUM> as the legacy device, it is to be understood that any such legacy device may be utilized in addition to or in lieu of Wi-Fi device <NUM>, e.g., a Wi-Fi device configured to communicate using a Wi-Fi RAT, a cellular device configured for communication using a different protocol (e.g., LAA, MultiFire, etc.), and/or a cellular device operating using a different protocol release (e.g., a release <NUM> configured cellular device). In some aspects, the <NUM> device <NUM> may refer to a device configured for V2X communications and the Wi-Fi device <NUM> may refer to any device that is not configured or otherwise communicating using V2X protocols.

Generally, process <NUM> illustrates one example for prioritized sharing on channel(s) between the <NUM> device <NUM> and the Wi-Fi device <NUM>. In some aspects, the channel(s) may be associated with a non-BSM radio frequency spectrum band. In some aspects, the <NUM> device <NUM> may have a higher transmission priority than Wi-Fi device <NUM>. For example, the <NUM> device <NUM> may be performing V2X protocol safety message transmissions in a non-BSM band whereas the Wi-Fi device <NUM> is using the non-BSM band for non-V2X communications. In some aspects, the process <NUM> illustrates one example where the legacy device (e.g., Wi-Fi device <NUM>) yields to <NUM> device <NUM> transmissions.

At <NUM>, <NUM> device <NUM> may identify a shared radio frequency spectrum band that is shared between <NUM> device <NUM> and Wi-Fi device <NUM>. The <NUM> device <NUM> may operate using a RAT that is different from the RAT used by Wi-Fi device <NUM>. In some example, the difference between the first and second RATs may refer to the first RAT used for V2X communications and the second RAT being used for other communications (e.g., non-V2X communications). Other examples of the differences between the RATs may include Wi-Fi vs cellular RATs, cellular RATs using different releases (e.g. release <NUM> vs release <NUM>), and the like. In some aspects, <NUM> device <NUM> may identify or otherwise determine that the band is shared based on monitoring one or more transmissions on the channel(s). For example, <NUM> device <NUM> may detect legacy transmissions (e.g., transmissions using a different RAT) on the channel(s) from Wi-Fi device <NUM>.

At <NUM>, <NUM> device <NUM> may generate a preamble for transmission on the shared band. The preamble may be decodable by the Wi-Fi device <NUM> (e.g., a legacy device). The preamble may carry or otherwise convey an indication of a transmission by <NUM> device <NUM> using the RAT that <NUM> device <NUM> is configured to communicate using (e.g., a V2X RAT). For example, <NUM> device <NUM> may configure a network allocation vector (NAV), a TxOP parameter, or other similar parameter in the preamble to convey an indication of a transmission duration for the transmission by <NUM> device <NUM> using the first RAT. That is, the preamble may be generated according to the Wi-Fi RAT (e.g., any non-V2X based RAT) protocols such that the preamble can be detected and decoded by any legacy device. The preamble may convey the transmission indication as a resource identifier (e.g., resource block indicator, time-frequency resource indication, and the like) that <NUM> device <NUM> will be using for <NUM> based transmissions.

In some aspects, the <NUM> based transmission may span a bandwidth of the shared band. For example, the <NUM> device <NUM> may select a bandwidth for the transmission and configure the preamble to carry or otherwise convey an indication of the bandwidth.

At <NUM>, <NUM> device <NUM> may transmit the configured preamble prior to the transmission using the first RAT, e.g., prior to the V2X or <NUM> based transmission. Thus, <NUM> device <NUM> may transmit the preamble that is decodable by the Wi-Fi device <NUM> RAT and then the V2X based transmission that is detectable and/or decodable by other <NUM> devices (e.g., other <NUM> C-V2X configured devices). The subsequent transmission may be a unicast and/or broadcast transmission. Thus, <NUM> device <NUM> may transmit Wi-Fi and/or LAA, eLAA, MultiFire, or any similar legacy preamble prior to any <NUM> C-V2X transmission. The legacy preambles may enable the non-V2X devices (e.g., legacy devices) inferring the <NUM> C-V2X transmission times.

In some aspects, <NUM> device <NUM> may perform a LBT procedure before the transmission using the first RAT. For example, <NUM> device <NUM> may perform the LBT procedure prior to the imminent transmission (e.g., a few microseconds) and may adjust the backoff parameters within a certain window if other <NUM> C-V2X transmissions are detected.

<FIG> illustrates an example of a process <NUM> that supports <NUM> cellular V2X design principles in accordance with various aspects of the present disclosure. In some examples, process <NUM> may implement aspects of wireless communication system <NUM>, process <NUM> and/or <NUM>, and/or diagram <NUM>. Process <NUM> may include a Wi-Fi device <NUM> and a <NUM> device <NUM>.

Generally, process <NUM> illustrates one example for prioritized sharing on channel(s) between the <NUM> device <NUM> and the Wi-Fi device <NUM>. In some aspects, the channel(s) may be associated with a non-BSM radio frequency spectrum band. In some aspects, the <NUM> device <NUM> may have a higher transmission priority than Wi-Fi device <NUM>. For example, the <NUM> device <NUM> may be performing V2X protocol safety message transmissions in a non-BSM band whereas the Wi-Fi device <NUM> is using the non-BSM band for non-V2X communications. In some aspects, the process <NUM> illustrates one example where the legacy device (e.g., Wi-Fi device <NUM>) yields to <NUM> device <NUM> transmissions by adopting a shorter or smaller TxOP duration. The shorter or smaller TxOP duration provides an increased number of opportunities for the <NUM> device <NUM> to capture the medium.

At <NUM>, Wi-Fi device <NUM> may identify a shared radio frequency spectrum band that is shared between the <NUM> device <NUM> and the Wi-Fi device <NUM>. The Wi-Fi device <NUM> may operate using a RAT that is different from the RAT used by <NUM> device <NUM>. In some example, the difference between the first and second RATs may refer to the first RAT used for V2X communications and the second RAT being used for other communications (e.g., non-V2X communications). Other examples of the differences between the RATs may include Wi-Fi vs cellular RATs, cellular RATs using different releases (e.g. release <NUM> vs release <NUM>), and the like. In some aspects, Wi-Fi device <NUM> may identify or otherwise determine that the band is shared based on monitoring one or more transmissions on the channel(s). For example, Wi-Fi device <NUM> may detect <NUM> transmissions (e.g., transmissions using a different RAT) on the channel(s) from <NUM> device <NUM>.

At <NUM>, Wi-Fi device <NUM> may identify a first TxOP duration associated with the first RAT. For example, Wi-Fi device <NUM> may identify or otherwise determine the TxOP duration used by <NUM> device <NUM> based on one or more received signals, based on preconfigured information, based on information received from a base station, and the like. Accordingly, Wi-Fi device <NUM> may identify which TxOP duration that <NUM> device <NUM> (and other <NUM> devices) are using for <NUM> transmissions (e.g., C-V2X transmissions). In one nonlimiting example, the TxOP duration for the <NUM> device <NUM> may be <NUM> microseconds, <NUM> millisecond, and the like.

At <NUM>, Wi-Fi device <NUM> may select a second TxOP duration for communications in the shared radio frequency spectrum band that is shorter (or smaller) than the first TxOP duration. For example, the second TxOP duration may be based on the first TxOP duration and may be selected to allow for <NUM> device <NUM> to gain access to the channel for priority communications. For example, the second TxOP duration may be <NUM> microseconds, in some examples, and may ensure that <NUM> device <NUM> will have at least three or more opportunities to capture the channel to perform <NUM> transmissions. In some aspects, the second TxOP duration may be selected as a percentage of the first TxOP duration, e.g., <NUM>%, <NUM>%, <NUM>%, <NUM>%, and the like. Selection of the second TxOP duration may provide for shorter transmission burst for legacy devices that allows <NUM> devices to have more opportunities to gain control of the channel.

At <NUM>, Wi-Fi device <NUM> may perform communication(s) on the shared radio frequency spectrum band using the second TxOP. That is, Wi-Fi device <NUM> may use the shorter TxOP duration for some or all subsequent legacy communications (e.g., all non C-V2X communications).

<FIG> shows a block diagram <NUM> of a wireless device <NUM> that supports <NUM> cellular V2X design principles in accordance with aspects of the present disclosure. Wireless device <NUM> may be an example of aspects of a UE <NUM> as described herein, e.g., a <NUM> device and/or a legacy device. Wireless device <NUM> may include receiver <NUM>, cellular V2X manager <NUM>, and transmitter <NUM>. Wireless device <NUM> may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses).

Receiver <NUM> may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to <NUM> cellular V2X design principles, etc.). Information may be passed on to other components of the device. The receiver <NUM> may be an example of aspects of the transceiver <NUM> described with reference to <FIG>. The receiver <NUM> may utilize a single antenna or a set of antennas.

Cellular V2X manager <NUM> may be an example of aspects of the cellular V2X manager <NUM> described with reference to <FIG>.

Cellular V2X manager <NUM> and/or at least some of its various sub-components may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions of the cellular V2X manager <NUM> and/or at least some of its various sub-components may be executed by a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), an 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. The cellular V2X manager <NUM> and/or at least some of its various sub-components may be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations by one or more physical devices. In some examples, cellular V2X manager <NUM> and/or at least some of its various sub-components may be a separate and distinct component in accordance with various aspects of the present disclosure. In other examples, cellular V2X manager <NUM> and/or at least some of its various sub-components may be combined with one or more other hardware components, including but not limited to an I/O component, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or a combination thereof in accordance with various aspects of the present disclosure.

In some aspects, cellular V2X manager <NUM> may decode a control channel transmission of a safety message in a V2X system during a first portion of a time period. Cellular V2X manager <NUM> may identify, based on the decoding, a pool of resource blocks (RBs) that are available for the time period. Cellular V2X manager <NUM> may select a subset of RBs from the available pool of RBs for a transmission during a second portion of the time period.

In some aspects, cellular V2X manager <NUM> may also identify, by a first device configured to communicate using a first RAT, a shared radio frequency spectrum band that is shared between the first device and a second device that is configured to communicate using a second RAT. Cellular V2X manager <NUM> may generate a preamble for transmission on the shared radio frequency spectrum band, the preamble configured to be decodable by the second device of the second RAT and conveying an indication of a transmission by the first device using the first RAT. Cellular V2X manager <NUM> may transmit the configured preamble prior to the transmission using the first RAT.

In some aspects, the cellular V2X manager <NUM> may also identify a shared radio frequency spectrum band that is shared between a first device that is configured to communicate using a first RAT and a second device that is configured to communicate using a second RAT. Cellular V2X manager <NUM> may identify, by the second device, a first TxOP duration associated with the first RAT. Cellular V2X manager <NUM> may select, based on the first TxOP duration, a second TxOP duration for communications on the shared radio frequency spectrum band, where the second TxOP duration is smaller than the first TxOP duration.

<FIG> shows a block diagram <NUM> of a wireless device <NUM> that supports <NUM> cellular V2X design principles in accordance with aspects of the present disclosure. Wireless device <NUM> may be an example of aspects of a wireless device <NUM> or a UE <NUM> as described herein, e.g., a <NUM> device and/or a legacy device. Wireless device <NUM> may include receiver <NUM>, cellular V2X manager <NUM>, and transmitter <NUM>. Wireless device <NUM> may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses).

Cellular V2X manager <NUM> may be an example of aspects of the cellular V2X manager <NUM> described with reference to <FIG>. Cellular V2X manager <NUM> may also include control channel decoder <NUM>, RB manager <NUM>, shared spectrum manager <NUM>, preamble manager <NUM>, and TxOP manager <NUM>.

Control channel decoder <NUM> may decode a control channel transmission of a safety message in a V2X system during a first portion of a time period. Control channel decoder <NUM> may monitor a set of channels during the first portion of the time period, the channels associated with control channel transmissions. Control channel decoder <NUM> may decode the one or more control channels based on the monitoring.

RB manager <NUM> may identify, based on the decoding, a pool of RBs that are available for the time period. RB manager <NUM> may select a subset of RBs from the available pool of RBs for a transmission during a second portion of the time period. RB manager <NUM> may determine, based on the decoding, a time and frequency resources allocated for data transmissions scheduled during the time period and at least one subsequent time period. RB manager <NUM> may identify the pool of RBs based on the determining.

Shared spectrum manager <NUM> may identify, by a first device configured to communicate using a first RAT, a shared radio frequency spectrum band that is shared between the first device and a second device that is configured to communicate using a second RAT. In some cases, the first RAT has a higher transmission priority than the second RAT. In some cases, the first RAT includes a V2X RAT and the second RAT includes one or more of a Wi-Fi RAT, a LTE-LAA) RAT, an enhanced LTE-LAA RAT, and a multi-fire RAT.

Preamble manager <NUM> may generate a preamble for transmission on the shared radio frequency spectrum band, the preamble configured to be decodable by the second device of the second RAT and conveying an indication of a transmission by the first device using the first RAT. Preamble manager <NUM> may transmit the configured preamble prior to the transmission using the first RAT. Preamble manager <NUM> may configure at least one of a NAV or a TxOP parameter in the preamble to convey an indication of a transmission duration for the transmission by the first device using the first RAT.

TxOP manager <NUM> may identify, by the second device, a first TxOP duration associated with the first RAT. TxOP manager <NUM> may select, based on the first TxOP duration, a second TxOP duration for communications on the shared radio frequency spectrum band, where the second TxOP duration is smaller than the first TxOP duration. TxOP manager <NUM> may perform one or more communications on the shared radio frequency spectrum band using the second TxOP.

<FIG> shows a block diagram <NUM> of a cellular V2X manager <NUM> that supports <NUM> cellular V2X design principles in accordance with aspects of the present disclosure. The cellular V2X manager <NUM> may be an example of aspects of a cellular V2X manager <NUM>, a cellular V2X manager <NUM>, or a cellular V2X manager <NUM> described with reference to <FIG>, <FIG>, and <FIG>. The cellular V2X manager <NUM> may include control channel decoder <NUM>, RB manager <NUM>, shared spectrum manager <NUM>, preamble manager <NUM>, TxOP manager <NUM>, selection manager <NUM>, transmission manager <NUM>, bandwidth manager <NUM>, and listen-before-talk (LBT) manager <NUM>. Each of these modules may communicate, directly or indirectly, with one another (e.g., via one or more buses).

Shared spectrum manager <NUM> may identify, by a first device configured to communicate using a first RAT, a shared radio frequency spectrum band that is shared between the first device and a second device that is configured to communicate using a second RAT. In some cases, the first RAT has a higher transmission priority than the second RAT. In some cases, the first RAT includes a V2X RAT and the second RAT includes one or more of a Wi-Fi RAT, a LTE-LAA RAT, an enhanced LTE-LAA RAT, and a multi-fire RAT.

Selection manager <NUM> may identify, based on the decoding, an ordered list of available RBs for the pool of RBs and select, according to the ordered list, the subset of RBs. Selection manager <NUM> may select, according to a random selection scheme, the subset of RBs. Selection manager <NUM> may hash, based on a UE identifier and a RB index, the RBs in the pool of RBs, select, according to the hashing, the subset of RBs. Selection manager <NUM> may select the subset of RBs according to an ordered list of the RBs in the pool of RBs, a random selection scheme, a RB index hashed to a UE identifier, or combinations thereof.

Transmission manager <NUM> may monitor, control, or otherwise manage aspects of transmissions for a UE. In some cases, the transmission during the second portion of the time period includes a unicast transmission, a broadcast transmission, or combinations thereof. In some cases, the transmission during the second portion of the time period includes a V2X transmission.

Bandwidth manager <NUM> may select a bandwidth for the transmission by the first device using the first RAT and configure the preamble to convey an indication of the bandwidth.

LBT manager <NUM> may perform a LBT procedure prior to the transmission by the first device using the first RAT and perform a backoff procedure when the LBT procedure indicates that the shared radio frequency spectrum band is occupied.

<FIG> shows a diagram of a system <NUM> including a device <NUM> that supports <NUM> cellular V2X design principles in accordance with aspects of the present disclosure. Device <NUM> may be an example of or include the components of wireless device <NUM>, wireless device <NUM>, or a UE <NUM> as described herein, e.g., may be a <NUM> device and/or a legacy device. Device <NUM> may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including cellular V2X manager <NUM>, processor <NUM>, memory <NUM>, software <NUM>, transceiver <NUM>, antenna <NUM>, and I/O controller <NUM>. These components may be in electronic communication via one or more buses (e.g., bus <NUM>). Device <NUM> may communicate wirelessly with one or more base stations <NUM>.

Processor <NUM> may include an intelligent hardware device, (e.g., a general-purpose processor, a DSP, a central processing unit (CPU), a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof). In some cases, processor <NUM> may be configured to operate a memory array using a memory controller. In other cases, a memory controller may be integrated into processor <NUM>. Processor <NUM> may be configured to execute computer-readable instructions stored in a memory to perform various functions (e.g., functions or tasks supporting <NUM> cellular V2X design principles).

In some cases, the memory <NUM> may contain, among other things, a basic input/output system (BIOS) that may control basic hardware or software operation such as the interaction with peripheral components or devices.

Software <NUM> may include code to implement aspects of the present disclosure, including code to support <NUM> cellular V2X design principles. Software <NUM> may be stored in a non-transitory computer-readable medium such as system memory or other memory. In some cases, the software <NUM> may not be directly executable by the processor but may cause a computer (e.g., when compiled and executed) to perform functions described herein.

However, in some cases the device may have more than one antenna <NUM>, that may be capable of concurrently transmitting or receiving multiple wireless transmissions.

<FIG> shows a flowchart illustrating a method <NUM> for <NUM> cellular V2X design principles in accordance with aspects of the present disclosure. The operations of method <NUM> may be implemented by a UE <NUM> or its components as described herein. For example, the operations of method <NUM> may be performed by a cellular V2X manager as described with reference to <FIG>. In some examples, a UE <NUM> may execute a set of codes to control the functional elements of the device to perform the functions described below. Additionally, the UE <NUM> may perform aspects of the functions described below using special-purpose hardware. In some aspects, the operations of method <NUM> may be implemented by a UE <NUM> configured as a <NUM> device, e.g., configured for C-V2X communications.

At block <NUM> the UE <NUM> may decode a control channel transmission of a safety message in a V2X system during a first portion of a time period. The operations of block <NUM> may be performed according to the methods described herein. In certain examples, aspects of the operations of block <NUM> may be performed by a control channel decoder as described with reference to <FIG>.

At block <NUM> the UE <NUM> may identify, based at least in part on the decoding, a pool of RBs that are available for the time period. The operations of block <NUM> may be performed according to the methods described herein. In certain examples, aspects of the operations of block <NUM> may be performed by a RB manager as described with reference to <FIG>.

At block <NUM> the UE <NUM> may select a subset of RBs from the available pool of RBs for a transmission during a second portion of the time period. The operations of block <NUM> may be performed according to the methods described herein. In certain examples, aspects of the operations of block <NUM> may be performed by a RB manager as described with reference to <FIG>.

At block <NUM> the UE <NUM> may identify, by a first device configured to communicate using a first RAT, a shared radio frequency spectrum band that is shared between the first device and a second device that is configured to communicate using a second RAT. The operations of block <NUM> may be performed according to the methods described herein. In certain examples, aspects of the operations of block <NUM> may be performed by a shared spectrum manager as described with reference to <FIG>.

At block <NUM> the UE <NUM> may generate a preamble for transmission on the shared radio frequency spectrum band, the preamble configured to be decodable by the second device of the second RAT and conveying an indication of a transmission by the first device using the first RAT. The operations of block <NUM> may be performed according to the methods described herein. In certain examples, aspects of the operations of block <NUM> may be performed by a preamble manager as described with reference to <FIG>.

At block <NUM> the UE <NUM> may transmit the configured preamble prior to the transmission using the first RAT. The operations of block <NUM> may be performed according to the methods described herein. In certain examples, aspects of the operations of block <NUM> may be performed by a preamble manager as described with reference to <FIG>.

<FIG> shows a flowchart illustrating a method <NUM> for <NUM> cellular V2X design principles in accordance with aspects of the present disclosure. The operations of method <NUM> may be implemented by a UE <NUM> or its components as described herein. For example, the operations of method <NUM> may be performed by a cellular V2X manager as described with reference to <FIG>. In some examples, a UE <NUM> may execute a set of codes to control the functional elements of the device to perform the functions described below. Additionally, the UE <NUM> may perform aspects of the functions described below using special-purpose hardware. In some aspects, the operations of method <NUM> may be implemented by a UE <NUM> configured as a legacy device, e.g., configured for non-V2X communications.

At block <NUM> the UE <NUM> may identify a shared radio frequency spectrum band that is shared between a first device that is configured to communicate using a first RAT and a second device that is configured to communicate using a second RAT. The operations of block <NUM> may be performed according to the methods described herein. In certain examples, aspects of the operations of block <NUM> may be performed by a shared spectrum manager as described with reference to <FIG>.

At block <NUM> the UE <NUM> may identify, by the second device, a first TxOP duration associated with the first RAT. The operations of block <NUM> may be performed according to the methods described herein. In certain examples, aspects of the operations of block <NUM> may be performed by a TxOP manager as described with reference to <FIG>.

At block <NUM> the UE <NUM> may select, based at least in part on the first TxOP duration, a second TxOP duration for communications on the shared radio frequency spectrum band, wherein the second TxOP duration is smaller than the first TxOP duration. The operations of block <NUM> may be performed according to the methods described herein. In certain examples, aspects of the operations of block <NUM> may be performed by a TxOP manager as described with reference to <FIG>.

It should be noted that the methods described above describe possible implementations, and that the operations and the functions may be rearranged or otherwise modified and that other implementations are possible.

The terms "system" and "network" are often used interchangeably. A code division multiple access (CDMA) system may implement a radio technology such as CDMA2000, Universal Terrestrial Radio Access (UTRA), etc. CDMA2000 covers IS-<NUM>, IS-<NUM>, and IS-<NUM> standards.

In LTE/LTE-A networks, including such networks described herein, the term evolved node B (eNB) may be generally used to describe the base stations. The wireless communications system or systems described herein may include a heterogeneous LTE/LTE-A or NR network in which different types of eNBs provide coverage for various geographical regions. For example, each eNB, next generation NodeB (gNB), or base station may provide communication coverage for a macro cell, a small cell, or other types of cell. The term "cell" may be used to describe a base station, a carrier or component carrier associated with a base station, or a coverage area (e.g., sector, etc.) of a carrier or base station, depending on context.

Base stations may include or may be referred to by those skilled in the art as a base transceiver station, a radio base station, an access point, a radio transceiver, a NodeB, eNodeB (eNB), gNB, Home NodeB, a Home eNodeB, or some other suitable terminology. The geographic coverage area for a base station may be divided into sectors making up only a portion of the coverage area. The wireless communications system or systems described herein may include base stations of different types (e.g., macro or small cell base stations). The UEs described herein may be able to communicate with various types of base stations and network equipment including macro eNBs, small cell eNBs, gNBs, relay base stations, and the like. There may be overlapping geographic coverage areas for different technologies.

Each communication link described herein-including, for example, wireless communications system <NUM> and process <NUM> of <FIG> and <FIG>-may include one or more carriers, where each carrier may be a signal made up of multiple sub-carriers (e.g., waveform signals of different frequencies).

Also, as used herein, including in the claims, "or" as used in a list of items (for example, 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). For example, an exemplary function that is described as "based on condition A" may be based on both a condition A and a condition B without departing from the scope of the present disclosure.

By way of example, and not limitation, non-transitory computer-readable media may comprise RAM, ROM, electrically erasable programmable read only memory (EEPROM), compact disk (CD) ROM or other optical disk 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 means 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.

Claim 1:
A method for vehicle-to-everything wireless communication (<NUM>), the method (<NUM>) comprising:
identifying (<NUM>), by a first device configured to communicate using a first radio access technology, RAT, a shared radio frequency spectrum band that is shared between the first device and a second device that is configured to communicate using a second RAT different from the first RAT;
generating (<NUM>) a preamble for transmission on the shared radio frequency spectrum band, the preamble configured to be decodable by the second device of the second RAT and conveying an indication of a transmission by the first device using the first RAT; and
transmitting (<NUM>) the preamble prior to the transmission using the first RAT.