Wireless communication using multiple listen before talk (LBT) threshold values

A method of wireless communication includes receiving, by a user equipment (UE) from a base station, a control message associated with a plurality of listen before talk (LBT) threshold values including a first LBT threshold value and a second LBT threshold value. The first LBT threshold value is associated with a first frequency spectrum, and the second LBT threshold value is associated with a second frequency spectrum different than the first frequency spectrum. The method further includes performing an LBT operation based on the first LBT threshold value and the second LBT threshold value. The method further includes, based on the LBT operation, performing a transmission by the UE using one or both of the first frequency spectrum or the second frequency spectrum.

TECHNICAL FIELD

Aspects of the present disclosure relate generally to wireless communication systems, and more particularly, to wireless communication systems that perform listen before talk (LBT) operations.

DESCRIPTION OF THE RELATED TECHNOLOGY

SUMMARY

In some aspects of the disclosure, a method of wireless communication includes receiving, by a user equipment (UE) from a base station, a control message associated with a plurality of listen before talk (LBT) threshold values including a first LBT threshold value and a second LBT threshold value. The first LBT threshold value is associated with a first frequency spectrum, and the second LBT threshold value is associated with a second frequency spectrum different than the first frequency spectrum. The method further includes performing an LBT operation based on the first LBT threshold value and the second LBT threshold value. The method further includes, based on the LBT operation, performing a transmission by the UE using one or both of the first frequency spectrum or the second frequency spectrum.

In some other aspects of the disclosure, an apparatus includes a receiver configured to receive, from a base station, a control message associated with a plurality of LBT threshold values including a first LBT threshold value and a second LBT threshold value. The first LBT threshold value is associated with a first frequency spectrum, and the second LBT threshold value is associated with a second frequency spectrum different than the first frequency spectrum. The apparatus further includes a transmitter configured to initiate a transmission using one or both of the first frequency spectrum or the second frequency spectrum. The transmission is based on an LBT operation that is based on the first LBT threshold value and the second LBT threshold value.

In some other aspects of the disclosure, a method of wireless communication includes transmitting, by a base station to a UE, a control message associated with a plurality of LBT threshold values including a first LBT threshold value and a second LBT threshold value. The first LBT threshold value is associated with a first frequency spectrum, and the second LBT threshold value is associated with a second frequency spectrum different than the first frequency spectrum. The method further includes receiving, from the UE, a transmission using one or both of the first frequency spectrum or the second frequency spectrum. The transmission is based on an LBT operation that is based on the first LBT threshold value and the second LBT threshold value.

In some other aspects of the disclosure, an apparatus includes a transmitter configured to transmit, to a UE, a control message associated with a plurality of LBT threshold values including a first LBT threshold value and a second LBT threshold value. The first LBT threshold value is associated with a first frequency spectrum, and the second LBT threshold value is associated with a second frequency spectrum different than the first frequency spectrum. The apparatus further includes a receiver configured to receive, from the UE, a transmission using one or both of the first frequency spectrum or the second frequency spectrum. The transmission is based on an LBT operation that is based on the first LBT threshold value and the second LBT threshold value.

In some other aspects of the disclosure, a non-transitory computer-readable medium stores instructions executable by a processor to perform operations. The operations include receiving, from a base station, a control message associated with a plurality of LBT threshold values including a first LBT threshold value and a second LBT threshold value. The first LBT threshold value is associated with a first frequency spectrum, and the second LBT threshold value is associated with a second frequency spectrum different than the first frequency spectrum. The operations further include performing an LBT operation based on the first LBT threshold value and the second LBT threshold value. The operations further include, based on the LBT operation, initiating a transmission using one or both of the first frequency spectrum or the second frequency spectrum.

In some other aspects of the disclosure, an apparatus includes a memory and one or more processors coupled to the memory. The one or more processors are configured to receive, from a base station, a control message associated with a plurality of LBT threshold values including a first LBT threshold value and a second LBT threshold value. The first LBT threshold value is associated with a first frequency spectrum, and the second LBT threshold value is associated with a second frequency spectrum different than the first frequency spectrum. The one or more processors are further configured to perform an LBT operation based on the first LBT threshold value and the second LBT threshold value and to initiate, based on the LBT operation, a transmission using one or both of the first frequency spectrum or the second frequency spectrum.

In some other aspects of the disclosure, an apparatus includes means for receiving, from a base station, a control message associated with a plurality of LBT threshold values including a first LBT threshold value and a second LBT threshold value. The first LBT threshold value is associated with a first frequency spectrum, and the second LBT threshold value is associated with a second frequency spectrum different than the first frequency spectrum. The apparatus further includes means for performing an LBT operation based on the first LBT threshold value and the second LBT threshold value and means for performing, based on the LBT operation, a transmission using one or both of the first frequency spectrum or the second frequency spectrum.

In some other aspects of the disclosure, a method of wireless communication includes determining, by a base station, that a first frequency spectrum is available for communication. The method further includes determining, by the base station, that a second frequency spectrum is available for communication. The second frequency spectrum is different than the first frequency spectrum. The method further includes transmitting, by the base station to a UE, a control message associated with a plurality of LBT threshold values including a first LBT threshold value and a second LBT threshold value. The first LBT threshold value is associated with the first frequency spectrum, and the second LBT threshold value is associated with the second frequency spectrum.

In some other aspects of the disclosure, a non-transitory computer-readable medium stores instructions executable by a processor to perform operations. The operations include determining that a first frequency spectrum is available for communication and determining that a second frequency spectrum is available for communication. The second frequency spectrum is different than the first frequency spectrum. The operations further include initiating transmission, to a UE, of a control message associated with a plurality of LBT threshold values including a first LBT threshold value and a second LBT threshold value. The first LBT threshold value is associated with the first frequency spectrum, and the second LBT threshold value is associated with the second frequency spectrum.

In some other aspects of the disclosure, an apparatus includes a memory and one or more processors coupled to the memory. The one or more processors are configured to determine that a first frequency spectrum is available for communication and to determine that a second frequency spectrum is available for communication. The second frequency spectrum is different than the first frequency spectrum. The one or more processors are further configured to initiate transmission, to a UE, of a control message associated with a plurality of LBT threshold values including a first LBT threshold value and a second LBT threshold value. The first LBT threshold value is associated with the first frequency spectrum, and the second LBT threshold value is associated with the second frequency spectrum.

In some other aspects of the disclosure, an apparatus includes means for determining that a first frequency spectrum is available for communication and for determining that a second frequency spectrum is available for communication, wherein the second frequency spectrum is different than the first frequency spectrum. The apparatus further includes means for transmitting, a UE, a control message associated with a plurality of LBT threshold values including a first LBT threshold value and a second LBT threshold value. The first LBT threshold value is associated with the first frequency spectrum, and the second LBT threshold value is associated with the second frequency spectrum.

DETAILED DESCRIPTION

Some communication systems share frequencies with neighboring communication systems of different technologies. For example, a fifth generation new radio (5G NR) communication system may share an unlicensed band (such as a 5 gigahertz (GHz) frequency band or a 6 GHz frequency band) with a WiFi communication network. To reduce or avoid interference due to WiFi transmissions, the 5G NR communication system may a listen before talk (LBT) operation to sense whether the unlicensed band is available prior to initiating a transmission using the unlicensed band. The LBT operation may succeed (and the transmission may be performed) if an amount of detected energy associated with the unlicensed band fails to satisfy an LBT threshold. In some other cases, the LBT operation may fail (and the transmission may be avoided or delayed) if the amount of detected energy satisfies the LBT threshold.

In some cases, the LBT threshold may affect throughput or communication quality. For example, in some cases, an LBT threshold for the LBT operation may be too “restrictive” (reducing a number of transmissions via the unlicensed band and reducing throughput). In some other cases, an LBT threshold may be too “relaxed” (increasing throughput but potentially causing interference and dropped packets).

A wireless communication in accordance with some aspects of the disclosure may use independently configurable LBT thresholds for multiple different frequency spectrums of an unlicensed band. In some cases, use of independently configurable LBT thresholds may enable the LBT thresholds to be dynamically determined based on the particular conditions in a wireless communication system. For example, due to dynamic scheduling, a communication using a frequency spectrum of an unlicensed band may dynamically change from a downlink transmission to an uplink transmission (or vice versa). By rescheduling from the downlink transmission to the uplink transmission, the communication may be subject to downlink-uplink “leakage” from another downlink communication that utilizes an adjacent frequency band. As a result, by independently selecting an LBT threshold for the communication, the LBT threshold may compensate for the downlink-uplink leakage (and reducing or avoiding instances where the LBT threshold is too “restrictive” or too “relaxed”).

FIG.1is a block diagram illustrating 5G network100including various base stations and UEs that support wireless communication using multiple LBT threshold values according to aspects of the present disclosure. The 5G network100includes a number of base stations105and other network entities. A base station may be a station that communicates with the UEs and may also be referred to as an evolved node B (eNB), a next generation eNB (gNB), an access point, and the like. Each base station105may provide communication coverage for a particular geographic area. In 3GPP, the term “cell” can refer to this particular geographic coverage area of a base station and/or a base station subsystem serving the coverage area, depending on the context in which the term is used.

The 5G network100may support synchronous or asynchronous operation. For synchronous operation, the base stations may have similar frame timing, and transmissions from different base stations may be approximately aligned in time. For asynchronous operation, the base stations may have different frame timing, and transmissions from different base stations may not be aligned in time.

The UEs115are dispersed throughout the wireless network100, and each UE may be stationary or mobile. A UE may also be referred to as a terminal, a mobile station, a subscriber unit, a station, or the like. A UE may be a cellular phone, a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a tablet computer, a laptop computer, a cordless phone, a wireless local loop (WLL) station, or the like. In one aspect, a UE may be a device that includes a Universal Integrated Circuit Card (UICC). In another aspect, a UE may be a device that does not include a UICC. In some aspects, UEs that do not include UICCs may also be referred to as internet of everything (IoE) or internet of things (IoT) devices. UEs115a-115dare examples of mobile smart phone-type devices accessing 5G network100A UE may also be a machine specifically configured for connected communication, including machine type communication (MTC), enhanced MTC (eMTC), narrowband IoT (NB-IoT) and the like. UEs115e-115kare examples of various machines configured for communication that access 5G network100. A UE may be able to communicate with any type of the base stations, whether macro base station, small cell, or the like. InFIG.1, a lightning bolt (e.g., communication links) indicates wireless transmissions between a UE and a serving base station, which is a base station designated to serve the UE on the downlink and/or uplink, or desired transmission between base stations, and backhaul transmissions between base stations.

FIG.2shows a block diagram of a design of a base station105and a UE115, which may be one of the base station and one of the UEs inFIG.1, that support wireless communication using multiple LBT threshold values according to some aspects of the disclosure. At the base station105, a transmit processor220may receive data from a data source212and control information from a controller/processor240. The control information may be for the PBCH, PCFICH, PHICH, PDCCH, EPDCCH, MPDCCH etc. The data may be for the PDSCH, etc. The transmit processor220may process (e.g., encode and symbol map) the data and control information to obtain data symbols and control symbols, respectively. The transmit processor220may also generate reference symbols, e.g., for the PSS, SSS, and cell-specific reference signal. A transmit (TX) multiple-input multiple-output (MIMO) processor230may perform spatial processing (e.g., precoding) on the data symbols, the control symbols, and/or the reference symbols, if applicable, and may provide output symbol streams to the modulators (MODs)232athrough232t. Each modulator232may process a respective output symbol stream (e.g., for OFDM, etc.) to obtain an output sample stream. Each modulator232may further process (e.g., convert to analog, amplify, filter, and upconvert) the output sample stream to obtain a downlink signal. Downlink signals from modulators232athrough232tmay be transmitted via the antennas234athrough234t, respectively.

At the UE115, the antennas252athrough252rmay receive the downlink signals from the base station105and may provide received signals to the demodulators (DEMODs)254athrough254r, respectively. Each demodulator254may condition (e.g., filter, amplify, downconvert, and digitize) a respective received signal to obtain input samples. Each demodulator254may further process the input samples (e.g., for OFDM, etc.) to obtain received symbols. A MIMO detector256may obtain received symbols from all the demodulators254athrough254r, perform MIMO detection on the received symbols if applicable, and provide detected symbols. A receive processor258may process (e.g., demodulate, deinterleave, and decode) the detected symbols, provide decoded data for the UE115to a data sink260, and provide decoded control information to a controller/processor280.

On the uplink, at the UE115, a transmit processor264may receive and process data (e.g., for the PUSCH) from a data source262and control information (e.g., for the PUCCH) from the controller/processor280. The transmit processor264may also generate reference symbols for a reference signal. The symbols from the transmit processor264may be precoded by a TX MIMO processor266if applicable, further processed by the modulators254athrough254r(e.g., for SC-FDM, etc.), and transmitted to the base station105. At the base station105, the uplink signals from the UE115may be received by the antennas234, processed by the demodulators232, detected by a MIMO detector236if applicable, and further processed by a receive processor238to obtain decoded data and control information sent by the UE115. The processor238may provide the decoded data to a data sink239and the decoded control information to the controller/processor240.

The controllers/processors240and280may direct the operation at the base station105and the UE115, respectively. The controller/processor240and/or other processors and modules at the base station105may perform or direct the execution of various processes for the techniques described herein, such as the operations illustrated inFIG.8. The controllers/processor280and/or other processors and modules at the UE115may also perform or control the operations illustrated inFIG.7and/or other processes for the techniques described herein. The memories242and282may store data and program codes for the base station105and the UE115, respectively. A scheduler244may schedule UEs for data transmission on the downlink and/or uplink.

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

For example, a network operating entity may be allocated certain time resources reserved for exclusive communication by the network operating entity using the entirety of the shared spectrum. The network operating entity may also be allocated other time resources where the entity is given priority over other network operating entities to communicate using the shared spectrum. These time resources, prioritized for use by the network operating entity, may be utilized by other network operating entities on an opportunistic basis if the prioritized network operating entity does not utilize the resources. Additional time resources may be allocated for any network operator to use on an opportunistic basis.

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

In general, four categories of LBT procedure have been suggested for sensing a shared channel for signals that may indicate the channel is already occupied. In a first category (CAT 1 LBT), no LBT or CCA is applied to detect occupancy of the shared channel. A second category (CAT 2 LBT), which may also be referred to as an abbreviated LBT, a single-shot LBT, or a 25-μs LBT, provides for the node to perform a CCA to detect energy above a predetermined threshold or detect a message or preamble occupying the shared channel. The CAT 2 LBT performs the CCA without using a random back-off operation, which results in its abbreviated length, relative to the next categories.

A third category (CAT 3 LBT) performs CCA to detect energy or messages on a shared channel, but also uses a random back-off and fixed contention window. Therefore, when the node initiates the CAT 3 LBT, it performs a first CCA to detect occupancy of the shared channel. If the shared channel is idle for the duration of the first CCA, the node may proceed to transmit. However, if the first CCA detects a signal occupying the shared channel, the node selects a random back-off based on the fixed contention window size and performs an extended CCA. If the shared channel is detected to be idle during the extended CCA and the random number has been decremented to 0, then the node may begin transmission on the shared channel. Otherwise, the node decrements the random number and performs another extended CCA. The node would continue performing extended CCA until the random number reaches 0. If the random number reaches 0 without any of the extended CCAs detecting channel occupancy, the node may then transmit on the shared channel. If at any of the extended CCA, the node detects channel occupancy, the node may re-select a new random back-off based on the fixed contention window size to begin the countdown again.

A fourth category (CAT 4 LBT), which may also be referred to as a full LBT procedure, performs the CCA with energy or message detection using a random back-off and variable contention window size. The sequence of CCA detection proceeds similarly to the process of the CAT 3 LBT, except that the contention window size is variable for the CAT 4 LBT procedure.

Use of a medium-sensing procedure to contend for access to an unlicensed shared spectrum may result in communication inefficiencies. This may be particularly evident when multiple network operating entities (e.g., network operators) are attempting to access a shared resource. In the 5G network100, base stations105and UEs115may be operated by the same or different network operating entities. In some examples, an individual base station105or UE115may be operated by more than one network operating entity. In other examples, each base station105and UE115may be operated by a single network operating entity. Requiring each base station105and UE115of different network operating entities to contend for shared resources may result in increased signaling overhead and communication latency.

FIG.3illustrates an example of a timing diagram300for coordinated resource partitioning that supports wireless communication using multiple LBT threshold values according to some aspects of the disclosure. The timing diagram300includes a superframe305, which may represent a fixed duration of time (e.g., 20 ms). The superframe305may be repeated for a given communication session and may be used by a wireless system such as 5G network100described with reference toFIG.1. The superframe305may be divided into intervals such as an acquisition interval (A-INT)310and an arbitration interval315. As described in more detail below, the A-INT310and arbitration interval315may be subdivided into sub-intervals, designated for certain resource types, and allocated to different network operating entities to facilitate coordinated communications between the different network operating entities. For example, the arbitration interval315may be divided into a plurality of sub-intervals320. Also, the superframe305may be further divided into a plurality of subframes325with a fixed duration (e.g., 1 ms). While timing diagram300illustrates three different network operating entities (e.g., Operator A, Operator B, Operator C), the number of network operating entities using the superframe305for coordinated communications may be greater than or fewer than the number illustrated in timing diagram300.

The A-INT310may be a dedicated interval of the superframe305that is reserved for exclusive communications by the network operating entities. In some examples, each network operating entity may be allocated certain resources within the A-INT310for exclusive communications. For example, resources330-amay be reserved for exclusive communications by Operator A, such as through base station105a, resources330-bmay be reserved for exclusive communications by Operator B, such as through base station105b, and resources330-cmay be reserved for exclusive communications by Operator C, such as through base station105c. Since the resources330-aare reserved for exclusive communications by Operator A, neither Operator B nor Operator C can communicate during resources330-a, even if Operator A chooses not to communicate during those resources. That is, access to exclusive resources is limited to the designated network operator. Similar restrictions apply to resources330-bfor Operator B and resources330-cfor Operator C. The wireless nodes of Operator A (e.g., UEs115or base stations105) may communicate any information desired during their exclusive resources330-a, such as control information or data.

When communicating over an exclusive resource, a network operating entity does not need to perform any medium sensing procedures (e.g., listen-before-talk (LBT) or clear channel assessment (CCA)) because the network operating entity knows that the resources are reserved. Because only the designated network operating entity may communicate over exclusive resources, there may be a reduced likelihood of interfering communications as compared to relying on medium sensing techniques alone (e.g., no hidden node problem). In some examples, the A-INT310is used to transmit control information, such as synchronization signals (e.g., SYNC signals), system information (e.g., system information blocks (SIBs)), paging information (e.g., physical broadcast channel (PBCH) messages), or random access information (e.g., random access channel (RACH) signals). In some examples, all of the wireless nodes associated with a network operating entity may transmit at the same time during their exclusive resources.

In some examples, resources may be classified as prioritized for certain network operating entities. Resources that are assigned with priority for a certain network operating entity may be referred to as a guaranteed interval (G-INT) for that network operating entity. The interval of resources used by the network operating entity during the G-INT may be referred to as a prioritized sub-interval. For example, resources335-amay be prioritized for use by Operator A and may therefore be referred to as a G-INT for Operator A (e.g., G-INT-OpA). Similarly, resources335-bmay be prioritized for Operator B, (e.g., G-INT-OpB), resources335-c(e.g., G-INT-OpC) may be prioritized for Operator C, resources335-dmay be prioritized for Operator A, resources335-emay be prioritized for Operator B, and resources335-fmay be prioritized for Operator C.

The various G-INT resources illustrated inFIG.3appear to be staggered to illustrate their association with their respective network operating entities, but these resources may all be on the same frequency bandwidth. Thus, if viewed along a time-frequency grid, the G-INT resources may appear as a contiguous line within the superframe305.

This partitioning of data may be an example of time division multiplexing (TDM). Also, when resources appear in the same sub-interval (e.g., resources340-aand resources335-b), these resources represent the same time resources with respect to the superframe305(e.g., the resources occupy the same sub-interval320), but the resources are separately designated to illustrate that the same time resources can be classified differently for different operators.

When resources are assigned with priority for a certain network operating entity (e.g., a G-INT), that network operating entity may communicate using those resources without having to wait or perform any medium sensing procedures (e.g., LBT or CCA). For example, the wireless nodes of Operator A are free to communicate any data or control information during resources335-awithout interference from the wireless nodes of Operator B or Operator C.

A network operating entity may additionally signal to another operator that it intends to use a particular G-INT. For example, referring to resources335-a, Operator A may signal to Operator B and Operator C that it intends to use resources335-a. Such signaling may be referred to as an activity indication. Moreover, since Operator A has priority over resources335-a, Operator A may be considered as a higher priority operator than both Operator B and Operator C. However, as discussed above, Operator A does not have to send signaling to the other network operating entities to ensure interference-free transmission during resources335-abecause the resources335-aare assigned with priority to Operator A.

Similarly, a network operating entity may signal to another network operating entity that it intends not to use a particular G-INT. This signaling may also be referred to as an activity indication. For example, referring to resources335-b, Operator B may signal to Operator A and Operator C that it intends not to use the resources335-bfor communication, even though the resources are assigned with priority to Operator B. With reference to resources335-b, Operator B may be considered a higher priority network operating entity than Operator A and Operator C. In such cases, Operators A and C may attempt to use resources of sub-interval320on an opportunistic basis. Thus, from the perspective of Operator A, the sub-interval320that contains resources335-bmay be considered an opportunistic interval (O-INT) for Operator A (e.g., O-INT-OpA). For illustrative purposes, resources340-amay represent the O-INT for Operator A. Also, from the perspective of Operator C, the same sub-interval320may represent an O-INT for Operator C with corresponding resources340-b. Resources340-a,335-b, and340-ball represent the same time resources (e.g., a particular sub-interval320), but are identified separately to signify that the same resources may be considered as a G-INT for some network operating entities and yet as an O-INT for others.

To utilize resources on an opportunistic basis, Operator A and Operator C may perform medium-sensing procedures to check for communications on a particular channel before transmitting data. For example, if Operator B decides not to use resources335-b(e.g., G-INT-OpB), then Operator A may use those same resources (e.g., represented by resources340-a) by first checking the channel for interference (e.g., LBT) and then transmitting data if the channel was determined to be clear. Similarly, if Operator C wanted to access resources on an opportunistic basis during sub-interval320(e.g., use an O-INT represented by resources340-b) in response to an indication that Operator B was not going to use its G-INT (e.g., resources335-b), Operator C may perform a medium sensing procedure and access the resources if available. In some cases, two operators (e.g., Operator A and Operator C) may attempt to access the same resources, in which case the operators may employ contention-based procedures to avoid interfering communications. The operators may also have sub-priorities assigned to them designed to determine which operator may gain access to resources if more than operator is attempting access simultaneously. For example, Operator A may have priority over Operator C during sub-interval320when Operator B is not using resources335-b(e.g., G-INT-OpB). It is noted that in another sub-interval (not shown) Operator C may have priority over Operator A when Operator B is not using its G-INT.

In some examples, a network operating entity may intend not to use a particular G-INT assigned to it, but may not send out an activity indication that conveys the intent not to use the resources. In such cases, for a particular sub-interval320, lower priority operating entities may be configured to monitor the channel to determine whether a higher priority operating entity is using the resources. If a lower priority operating entity determines through LBT or similar method that a higher priority operating entity is not going to use its G-INT resources, then the lower priority operating entities may attempt to access the resources on an opportunistic basis as described above.

In some examples, access to a G-INT or O-INT may be preceded by a reservation signal (e.g., request-to-send (RTS)/clear-to-send (CTS)), and the contention window (CW) may be randomly chosen between one and the total number of operating entities.

In some examples, an operating entity may employ or be compatible with coordinated multipoint (CoMP) communications. For example an operating entity may employ CoMP and dynamic time division duplex (TDD) in a G-INT and opportunistic CoMP in an O-INT as needed.

In the example illustrated inFIG.3, each sub-interval320includes a G-INT for one of Operator A, B, or C. However, in some cases, one or more sub-intervals320may include resources that are neither reserved for exclusive use nor reserved for prioritized use (e.g., unassigned resources). Such unassigned resources may be considered an O-INT for any network operating entity, and may be accessed on an opportunistic basis as described above.

In some examples, each subframe325may contain 14 symbols (e.g., 250-μs for 60 kHz tone spacing). These subframes325may be standalone, self-contained Interval-Cs (ITCs) or the subframes325may be a part of a long ITC. An ITC may be a self-contained transmission starting with a downlink transmission and ending with an uplink transmission. In some examples, an ITC may contain one or more subframes325operating contiguously upon medium occupation. In some cases, there may be a maximum of eight network operators in an A-INT310(e.g., with duration of 2 ms) assuming a 250-μs transmission opportunity.

Although three operators are illustrated inFIG.3, it should be understood that fewer or more network operating entities may be configured to operate in a coordinated manner as described above. In some cases, the location of the G-INT, O-INT, or A-INT within the superframe305for each operator is determined autonomously based on the number of network operating entities active in a system. For example, if there is only one network operating entity, each sub-interval320may be occupied by a G-INT for that single network operating entity, or the sub-intervals320may alternate between G-INTs for that network operating entity and O-INTs to allow other network operating entities to enter. If there are two network operating entities, the sub-intervals320may alternate between G-INTs for the first network operating entity and G-INTs for the second network operating entity. If there are three network operating entities, the G-INT and O-INTs for each network operating entity may be designed as illustrated inFIG.3. If there are four network operating entities, the first four sub-intervals320may include consecutive G-INTs for the four network operating entities and the remaining two sub-intervals320may contain O-INTs. Similarly, if there are five network operating entities, the first five sub-intervals320may contain consecutive G-INTs for the five network operating entities and the remaining sub-interval320may contain an O-INT. If there are six network operating entities, all six sub-intervals320may include consecutive G-INTs for each network operating entity. It should be understood that these examples are for illustrative purposes only and that other autonomously determined interval allocations may be used.

It should be understood that the coordination framework described with reference toFIG.3is for illustration purposes only. For example, the duration of superframe305may be more or less than 20 ms. Also, the number, duration, and location of sub-intervals320and subframes325may differ from the configuration illustrated. Also, the types of resource designations (e.g., exclusive, prioritized, unassigned) may differ or include more or less sub-designations.

FIG.4is a block diagram illustrating an example of a wireless communication system400that supports wireless communication using multiple LBT threshold values according to some aspects of the disclosure. The wireless communication system400may include one or more base stations, such as the base station105, and may include one or more UEs, such as the UE115.

The example ofFIG.4illustrates that the base station105may include one or more processors (such as the controller/processor240) and may include the memory242. The base station105may further include a transmitter306and a receiver308. The controller/processor240may be coupled to the memory242, to the transmitter306, and to the receiver308. In some examples, the transmitter306and the receiver308include one or more components described with reference toFIG.2, such as one or more of the modulator/demodulators232a-t, the MIMO detector236, the receive processor238, the transmit processor220, or the TX MIMO processor230. In some implementations, the transmitter306and the receiver308may be integrated in one or more transceivers of the base station105.

The transmitter306may be configured to transmit reference signals, synchronization signals, control information, and data to one or more other devices, and the receiver308may be configured to receive reference signals, control information, and data from one or more other devices. For example, the transmitter306may be configured to transmit signaling, control information, and data to the UE115, and the receiver308may be configured to receive signaling, control information, and data from the UE115.

FIG.4also illustrates that the UE115may include one or more processors (such as the controller/processor280), a memory (such as the memory282), a transmitter356, and a receiver358. The controller/processor280may be coupled to the memory282, to the transmitter356, and to the receiver358. In some examples, the transmitter356and the receiver358may include one or more components described with reference toFIG.2, such as one or more of the modulator/demodulators254a-r, the MIMO detector256, the receive processor258, the transmit processor264, or the TX MIMO processor266. In some implementations, the transmitter356and the receiver358may be integrated in one or more transceivers of the UE115.

The transmitter356may be configured to transmit reference signals, synchronization signals, control information, and data to one or more other devices, and the receiver358may be configured to receive reference signals, control information, and data from one or more other devices. For example, in some implementations, the transmitter356may be configured to transmit signaling, control information, and data to the base station105, and the receiver358may be configured to receive signaling, control information, and data from the base station105.

In some implementations, one or more of the transmitter306, the receiver308, the transmitter356, or the receiver358may include an antenna array. The antenna array may include multiple antenna elements that perform wireless communications with other devices. In some implementations, the antenna array may perform wireless communications using different beams, also referred to as antenna beams. The beams may include transmit beams and receive beams. To illustrate, the antenna array may include multiple independent sets (or subsets) of antenna elements (or multiple individual antenna arrays), and each set of antenna elements of the antenna array may be configured to communicate using a different respective beam that may have a different respective direction than the other beams. For example, a first set of antenna elements of the antenna array may be configured to communicate via a first beam having a first direction, and a second set of antenna elements of the antenna array may be configured to communicate via a second beam having a second direction. In other implementations, the antenna array may be configured to communicate via more than two beams. In some implementations, one or more sets of antenna elements of the antenna array may be configured to concurrently generate multiple beams, for example using multiple RF chains. A set (or subset) of antenna elements may include multiple antenna elements, such as two antenna elements, four antenna elements, ten antenna elements, twenty antenna elements, or any other number of antenna elements greater than two. Although described as an antenna array, in other implementations, the antenna array may include or correspond to multiple antenna panels, and each antenna panel may be configured to communicate using a different respective beam.

In some implementations, the wireless communication system400operates in accordance with a 5G NR network. For example, the wireless communication system400may include multiple 5G-capable UEs115and multiple 5G-capable base stations105, such as UEs and base stations configured to operate in accordance with a 5G NR network protocol such as that defined by the 3GPP.

During operation, the base station105and the UE115may communicate using a first frequency spectrum410and a second frequency spectrum420. One or both of the frequency spectrums410,420may be included in an unlicensed spectrum, such as a 5 gigahertz (GHz) unlicensed spectrum or a 6 GHz unlicensed spectrum, as illustrative examples. In some examples, the frequency spectrums410,420may be associated with one or more features described with reference toFIG.3. For example, one or both of the frequency spectrums410,420may be accessed on an opportunistic basis, such as described with reference to the sub-interval320ofFIG.3.

In some implementations, the base station105configures to the UE115to use the first frequency spectrum410and the second frequency spectrum420. For example, the base station105may determine that the first frequency spectrum410and the second frequency spectrum420are available for communication (e.g., based on success of one or more LBT operations). Based on determining that the first frequency spectrum410and the second frequency spectrum420are available for communication, the base station105may transmit to the UE115a control message432associated with LBT threshold values452. The LBT threshold values452may include a first LBT threshold value454(e.g., a bandwidth-specific LBT threshold value) associated with the first frequency spectrum410and a second LBT threshold value456(e.g., another bandwidth-specific LBT threshold value) associated with the second frequency spectrum420. In some implementations, the control message432may have one of a downlink control information (DCI) 2_0 format, a radio resource control (RRC) format, or a medium access control (MAC) control element (MAC-CE) format. In some examples, the UE115selects the LBT threshold values454,456from a mapping table470of index values to LBT threshold values based on the control message432.

In one example, the UE115selects the values from the mapping table470on a per-row basis based on a particular index value (e.g., a single index value) indicated by the control message432. In this example, the control message432may indicate an index value that corresponds to a particular row of the mapping table470, and the UE115may use the index value as a lookup to the particular row to determine the LBT threshold values454,456. To illustrate, the mapping table may include a first row471and a second row481. The first row471may include an LBT threshold value473associated with the first frequency spectrum410and an LBT threshold value475associated with the second frequency spectrum420, and the second row481may include an LBT threshold value483associated with the first frequency spectrum410and an LBT threshold value485associated with the second frequency spectrum420. In some examples, the control message432indicates a first index value associated with the first row471, and the UE115selects the LBT threshold values473,475based on the control message432. In this case, the LBT threshold values454,456may correspond to the LBT threshold values473,475, respectively. In some other examples, the control message432indicates a second index value associated with the second row481, and the UE115selects the LBT threshold values483,485based on the control message432. In this case, the LBT threshold values454,456may correspond to the LBT threshold values483,485, respectively.

In some other examples, the control message432may individually identify each of the LBT threshold values452on an per-value basis (instead of on a per-row basis). In this case, the control message432may include multiple index values that individually indicate LBT threshold values of the mapping table470(instead of including a single index value that indicates a particular row of the mapping table470). To illustrate, the mapping table470may include an index value472associated with the LBT threshold value473, an index value474associated with the LBT threshold value475, an index value482associated with the LBT threshold value483, and an index value484associated with the LBT threshold value485. The control message432may include a first index value corresponding to one of the index values472,474,482, and484and may further include a second index value corresponding to another of the index values472,474,482, and484. The UE115may access the mapping table470to determine the first LBT threshold value454based on the first index value and to determine the second LBT threshold value456based on the second index value.

In some examples, the first index value includes a first number of bits, and the second index value includes a second number of bits. The base station105may independently determine the first number of bits and the second number of bits to indicate a first resolution associated with the first LBT threshold value454and to indicate a second resolution associated with the second LBT threshold value456, respectively. As a non-limiting illustrative example, the mapping table470may indicate that the LBT threshold value472has a value of 72.123 decibels relative to one milliwatt (dBm), and the control message432may represent the index value472using the first number of bits. If the first number of bits indicates that the first resolution is two significant digits, then the first LBT threshold value454may correspond to 72 dBm. If the first number of bits indicates that the first resolution is three significant digits, then the first LBT threshold value454may correspond to 72.1 dBm. If the first number of bits indicates that the first resolution is four significant digits, then the first LBT threshold value454may correspond to 72.12 dBm.

In some implementations, the base station105(or another network device) provides the mapping table470to the UE115. For example, the base station105may transmit a configuration message430to the UE115indicating the mapping table470. The configuration message430may dynamically configure the UE115with the mapping table470and may be used to update the mapping table470dynamically duration operation of the wireless communication system400. The configuration message430may have an RRC format, as an illustrative example. In some other examples, the base station105and the UE115operate based on a wireless communication protocol that specifies the mapping table470. In some examples, the UE115is provisioned with the mapping table470by a manufacturer of the UE115.

After determining the LBT threshold values452based on the control message432, the UE115may perform one or more LBT operations based on the LBT threshold values452, such as an LBT operation450. For example, the UE115may sense the first frequency spectrum410to determine a first energy value464associated with signals, noise, or interference sensed via the first frequency spectrum410and may sense the second frequency spectrum420to determine a second energy value466associated with signals, noise, or interference sensed via the second frequency spectrum420. Depending on the particular implementation, the UE115may sense the first frequency spectrum410concurrently (e.g., using multiple receive paths of the UE115), partially concurrently, or sequentially (e.g., using a single receive path of the UE115) with sensing the second frequency spectrum420.

In some examples, performing the LBT operation450may include comparing the first energy value464to the first LBT threshold value454to determine whether the first energy value464satisfies (e.g., exceeds) the first LBT threshold value454. Based on the first energy value464failing to satisfy the first LBT threshold value454, the UE115may determine that the first frequency spectrum410is available for a transmission436. In some other examples, the first energy value464may satisfy the first LBT threshold value454, and the UE115may determine that the first frequency spectrum410is unavailable. The LBT operation450may also include comparing the second energy value466to the second LBT threshold value456to determine whether the second energy value466satisfies (e.g., exceeds) the second LBT threshold value456. Based on the second energy value466failing to satisfy the second LBT threshold value456, the UE115may determine that the second frequency spectrum420is available for the transmission436(or another transmission). In some other examples, the second energy value466may satisfy the second LBT threshold value456, and the UE115may determine that the second frequency spectrum420is unavailable.

In some examples, the first LBT threshold value454is different than the second LBT threshold value456. If the transmission436is to include transmitting an uplink signal438using both the first frequency spectrum410and the second frequency spectrum420, then a circumstance may occur in which the first frequency spectrum410is available and the second frequency spectrum420is unavailable (or vice versa). In one example, the UE115determines success of the LBT operation450on a collective basis (e.g., based on determining that each of the LBT threshold values452is not satisfied). For example, if the UE115determines that the first energy value464fails to satisfy the first LBT threshold value454and that the second energy value466fails to satisfy the second LBT threshold value456, then the UE115may determine success of the LBT operation450. In this case, the UE115may perform the transmission436of the uplink signal438using both the first frequency spectrum410and the second frequency spectrum420. In some other examples, the UE115may determine that the first energy value464satisfies the first LBT threshold value454, that the second energy value466satisfies the second LBT threshold value456or both. In this case, the UE115may determine failure of the LBT operation450and may decline (or delay) performance of the transmission436.

In another example, the LBT operation450may include determining a composite energy value467associated with both the first frequency spectrum410and the second frequency spectrum420and may further include determining a composite LBT threshold value468based on the LBT threshold values452. In some examples, the UE115sums the energy values464,466to determine the composite energy value467or senses the frequency spectrums410,420collectively to determine the composite energy value467. The UE115may determine success of the LBT operation450based on the composite energy value467failing to satisfy the composite LBT threshold value468or may determine failure of the LBT operation450based on the composite energy value467satisfying the composite LBT threshold value468.

In some examples, the UE115may determine the composite LBT threshold value by identifying a maximum value of the LBT threshold values452and may select the maximum value as the composite LBT threshold value468. As an example, if the first LBT threshold value454is greater than the second LBT threshold value456, then the UE115may select the first LBT threshold value454as the composite LBT threshold value468. As another example, if the second LBT threshold value456is greater than the first LBT threshold value454, then the UE115may select the second LBT threshold value456as the composite LBT threshold value468.

In some other examples, the UE115may determine the composite LBT threshold value by identifying a minimum value of the LBT threshold values452and may select the minimum value as the composite LBT threshold value468. As an example, if the first LBT threshold value454is less than the second LBT threshold value456, then the UE115may select the first LBT threshold value454as the composite LBT threshold value468. As another example, if the second LBT threshold value456is less than the first LBT threshold value454, then the UE115may select the second LBT threshold value456as the composite LBT threshold value468.

In another example, composite LBT threshold value468may correspond to an average of the LBT threshold values452. Depending on the particular implementation, the average of the LBT threshold values452may refer to an arithmetic mean of the LBT threshold values452, a geometric mean of the LBT threshold values452, a harmonic mean of the LBT threshold values452, a median value of the LBT threshold values452, a mode value of the LBT threshold values452, or another type of average of the LBT threshold values452. In some other examples, determining the composite LBT threshold value468may include performing one or more operations based on another particular function of the plurality of LBT threshold values452.

In another example, the composite LBT threshold value468corresponds to a predetermined LBT threshold value that is reserved for LBT operations associated with multiple different LBT threshold values. For example, the base station105may indicate the predetermined LBT threshold value to the UE115using the configuration message430or the control message432, and the UE115may use the predetermined LBT threshold value in connection with the LBT operation450based on determining that the first LBT threshold value454differs from the second LBT threshold value456.

FIG.5is a block diagram illustrating an example of a bandwidth part (BWP)500that supports wireless communication using multiple LBT threshold values according to some aspects of the disclosure. InFIG.5, the abscissa may indicate frequency. The BWP500may include a first resource block (RB) set502, a second RB set504, a third RB set506, and a fourth RB set508. In some examples, RB sets of the BWP500may be separated by a guard band, such as a representative guard band503separating the first RB set502and the second RB set504.

In some examples, each of the RB sets502,504,506, and508corresponds to a respective channel access unit that is used (or accessible to) devices of another wireless communication network that is different than the wireless communication system400ofFIG.4. As an illustrative example, each of the RB sets502,504,506, and508may correspond to a respective 20 megahertz (MHz) WiFi channel access unit that is used (or accessible to) WiFi devices of a WiFi communication network. To avoid interference or resource conflicts, devices of the wireless communication system400ofFIG.4may perform LBT operations (such as the LBT operation450) prior to using the RB sets502,504,506, and508. Further, the RB sets502,504,506, and508may be referred to as LBT bandwidths.

In some implementations, an LBT threshold value may be associated with a respective LBT bandwidth (e.g., on a one-to-one basis). To illustrate, the first frequency spectrum410ofFIG.4may be associated with one of the RB sets502,504,506, and508(e.g., the first RB set502), and the second frequency spectrum420ofFIG.4may be associated with another of the RB sets502,504,506, and508(e.g., the second RB set504). In this case, the first frequency spectrum410ofFIG.4may include frequencies of the first RB set502, and the second frequency spectrum420ofFIG.4may include frequencies of the second RB set504. Alternatively or in addition, an LBT threshold value may be associated with multiple LBT bandwidths (e.g., on a one-to-many basis). For example, the first frequency spectrum410ofFIG.4may be associated with multiple RB sets of the RB sets502,504,506, and508(e.g., the RB sets502and504), and the second frequency spectrum420ofFIG.4may be associated with multiple other RB sets of the RB sets502,504,506, and508(e.g., the RB sets506and508). In this case, the first frequency spectrum410ofFIG.4may include frequencies of the RB sets502and504, and the second frequency spectrum420ofFIG.4may include frequencies of the RB sets506and508.

Although certain examples ofFIGS.4and5describe two frequency spectrums410and420, two LBT threshold values454and456, and four RB sets502,504,506, and508, it is noted that other examples are also within the scope of the disclosure. For example, three or more frequency spectrums and three or more LBT threshold values may be used. As another example, two RB sets, three RB sets, or five or more RB sets may be included in the BWP500ofFIG.5.

In some cases, the base station105ofFIG.4may determine that a third frequency spectrum is unavailable for communication, and the LBT threshold values452may exclude any LBT threshold value associated with the third frequency spectrum. To illustrate, if the base station105determines that frequencies of the third RB set506are unavailable for communication, then the base station105may exclude any LBT threshold value associated with the third RB set506from the LBT threshold values452(which may prevent the UE115from expending power and resources attempting to communicate using the third frequency spectrum).

FIG.6is a block diagram illustrating examples of transmission schemes600that may be associated with the RB sets of the BWP500ofFIG.5to support wireless communication using multiple LBT threshold values according to some aspects of the disclosure. The transmission schemes600may include a first transmission scheme610, a second transmission scheme620, and a third transmission scheme630. In some examples, the base station105schedules the third transmission scheme630dynamically, such as by combining uplink transmissions612,613of the first transmission scheme610with downlink transmissions621,624of the second transmission scheme620. In some examples, the UE115receives downlink communications from the base station105via the downlink transmissions621,624using the RB sets502,508and transmits uplink signals (such as the uplink signal438) to the base station105via the uplink transmissions612,613using the RB sets504,506.

In some implementations, uplink transmissions of the first transmission scheme610may include a first number of frequency resources, and downlink transmissions of the second transmission scheme620may include a second number of frequency resources different than the first number. In some examples, the first number is greater than the second number (e.g., as shown in the example ofFIG.6, where uplink transmissions of the first transmission scheme610are illustrated as being wider than downlink transmissions of the second transmission scheme620). In some implementations, a guard band separating uplink transmissions of the first transmission scheme610may be narrower (and may include fewer frequency resources) than a guard band separating downlink transmissions of the second transmission scheme620. After combining the uplink transmissions612,613with the downlink transmissions621,624, the third transmission scheme630may have a “mixture” of different transmission widths and guard band widths (such as where the third transmission scheme630includes transmission widths and guard band widths associated with both the first transmission scheme610and the second transmission scheme620).

In some aspects of the disclosure, the base station105may select the LBT threshold values452based on an estimated uplink-downlink leakage associated with a transmission scheme. For example, in some cases, RB sets associated with an uplink transmission may be adjacent to RB sets associated with a downlink transmission. In this case, energy leakage from the downlink to the uplink (or vice versa) may occur. To compensate for the energy leakage, the base station105may adjust LBT threshold values associated with the RB sets. For example, an uplink transmission that is adjacent to a downlink transmission may be associated with a different LBT threshold value (e.g., an increased LBT threshold value or a decreased LBT threshold value) to compensate for potential increased energy leakage that may increase an amount of detected energy, and another uplink transmission that is non-adjacent to any downlink transmission may be associated with a lower LBT threshold value (based on less potential energy leakage). In some implementations, an LBT threshold value for a downlink transmission that is adjacent to another downlink transmission can be adjusted by a particular value, such as a particular number of dBm. In another example, an LBT threshold value for a downlink transmission that is adjacent to another downlink transmission can be adjusted by a certain percentage.

To further illustrate, in some examples, the base station105determines the first LBT threshold value454based at least in part on whether the first frequency spectrum410is adjacent to a frequency spectrum scheduled for a downlink communication and determines the second LBT threshold value456based at least in part on whether the second frequency spectrum420is adjacent to a frequency spectrum scheduled for a downlink communication. In one example, one of the frequency spectrums410,420is adjacent to a downlink frequency band, the other of the frequency spectrums410,420is non-adjacent to a downlink frequency band, and the first LBT threshold value454is different than the second LBT threshold value456.

One or more aspects described herein may improve performance of a wireless communication system. For example, by independently configuring the LBT threshold values452, the LBT operation450may reflect dynamic conditions within the wireless communication system400, such as whether or not the one or both of the frequency spectrums410,420are adjacent to a downlink frequency band, which may be associated with leakage and which may affect results of the LBT operation450in some cases.

FIG.7is a flow chart illustrating an example of a method700of wireless communication that supports wireless communication using multiple LBT threshold values according to some aspects of the disclosure. In some examples, the method700is performed by a UE, such as by the UE115.

The method700includes receiving, by a UE from a base station, a control message associated with a plurality of LBT threshold values including a first LBT threshold value and a second LBT threshold value, at702. The first LBT threshold value is associated with a first frequency spectrum, and the second LBT threshold value is associated with a second frequency spectrum different than the first frequency spectrum. For example, the UE115may receive the control message432from the base station105, and the control message may be associated with the LBT threshold values454,456. The first LBT threshold value454may be associated with the first frequency spectrum410, and the second LBT threshold value456may be associated with the second frequency spectrum420.

The method700further includes performing an LBT operation based on the first LBT threshold value and the second LBT threshold value, at704. For example, the UE115may perform the LBT operation450based on the first LBT threshold value454and the second LBT threshold value456.

The method700further includes, based on the LBT operation, performing, by the UE, a transmission using one or both of the first frequency spectrum or the second frequency spectrum, at706. For example, the UE115may perform the transmission436using the first frequency spectrum410, the second frequency spectrum420, or both.

FIG.8is a flow chart illustrating an example of a method800of wireless communication that supports wireless communication using multiple LBT threshold values according to some aspects of the disclosure. In some examples, the method800is performed by a base station, such as by the base station105.

The method800may include determining, by a base station, that a first frequency spectrum is available for communication, at802. For example, the base station105may determine availability of the first frequency spectrum410, such as based on a successful result of an LBT operation performed by the base station105.

The method800may further include determining, by the base station, that a second frequency spectrum is available for communication, where the second frequency spectrum is different than the first frequency spectrum, at804. For example, the base station105may determine availability of the second frequency spectrum420, such as based on a successful result of an LBT operation performed by the base station105.

The method800further includes transmitting, by the base station to a UE, a control message associated with a plurality of LBT threshold values including a first LBT threshold value and a second LBT threshold value, at806. The first LBT threshold value is associated with the first frequency spectrum, and the second LBT threshold value is associated with the second frequency spectrum. For example, the base station105may transmit, to the UE115, the control message432associated with the LBT threshold values454,456. The first LBT threshold value454may be associated with the first frequency spectrum410, and the second LBT threshold value456may be associated with the second frequency spectrum420.

The method800further includes receiving, from the UE, a transmission using one or both of the first frequency spectrum or the second frequency spectrum, at808. The transmission is based on an LBT operation that is based on the first LBT threshold value and the second LBT threshold value. For example, the base station105may receive the transmission436using one or both of the first frequency spectrum410or the second frequency spectrum420. The transmission436may be based on the LBT operation450, and the LBT operation may be based on the first LBT threshold value454and the second LBT threshold value456.

FIG.9is a block diagram illustrating an example of the UE115that supports wireless communication using multiple LBT threshold values according to some aspects of the disclosure. The UE115may include structure, hardware, or components illustrated inFIG.2. For example, the UE115may include the controller/processor280, which may execute instructions stored in the memory282. Using the controller/processor280, the UE115may transmit and receive signals via wireless radios901a-rand antennas252a-r. The wireless radios901a-rmay include one or more components or devices described herein, such as the modulator/demodulators254a-r, the MIMO detector256, the receive processor258, the transmit processor264, the TX MIMO processor266, the transmitter356, the receiver358, one or more other components or devices, or a combination thereof.

In some examples, the controller/processor280executes mapping table lookup instructions902to perform a lookup operation to the mapping table470to determine multiple LBT threshold values452based on the control message432ofFIG.4. For example, the control message432may indicate an index value associated with the first row471, an index associated with the second row481, or an index value associated with a particular LBT threshold value (such as any of the index values472,474,482, and482). The controller/processor280may execute multi-threshold LBT operation instructions904to perform an LBT operation based on multiple LBT threshold values, such as to perform the LBT operation450based on the LBT threshold values454,456.

FIG.10is a block diagram illustrating an example of the base station105that supports wireless communication using multiple LBT threshold values according to some aspects of the disclosure. The base station105may include structure, hardware, and components illustrated inFIG.2. For example, the base station105may include the controller/processor240, which may execute instructions stored in memory242. Under control of the controller/processor240, the base station105may transmit and receive signals via wireless radios1001a-tand antennas234a-t. The wireless radios1001a-tmay include one or more components or devices described herein, such as the modulator/demodulators232a-t, the MIMO detector236, the receive processor238, the transmit processor220, the TX MIMO processor230, the transmitter306, the receiver308, one or more other components or devices, or a combination thereof.

In some examples, the controller/processor240executes scheduling instructions1002to schedule communication associated with the wireless communications system400, such as to communications in accordance with the transmission schemes600ofFIG.6. The controller/processor240may execute dynamic LBT threshold value selection instructions1004to determine the LBT threshold values452and to transmit the control message432to indicate the LBT threshold values452to the UE115.

According to some further aspects, in a first aspect, a method of wireless communication includes receiving, by a user equipment (UE) from a base station, a control message associated with a plurality of listen before talk (LBT) threshold values including a first LBT threshold value and a second LBT threshold value. The first LBT threshold value is associated with a first frequency spectrum, and the second LBT threshold value is associated with a second frequency spectrum different than the first frequency spectrum. The method further includes performing an LBT operation based on the first LBT threshold value and the second LBT threshold value. The method further includes, based on the LBT operation, performing a transmission by the UE using one or both of the first frequency spectrum or the second frequency spectrum.

In a second aspect alternatively or in addition to the first aspect, the first LBT threshold value is based at least in part on whether the first frequency spectrum is adjacent to a frequency spectrum scheduled for a downlink communication, and the second LBT threshold value is based at least in part on whether the second frequency spectrum is adjacent to a frequency spectrum scheduled for a downlink communication.

In a third aspect alternatively or in addition to any of the first through second aspects, one of the first frequency spectrum or the second frequency spectrum is adjacent to a downlink frequency band, the other of the first frequency spectrum or the second frequency spectrum is non-adjacent to a downlink frequency band, and the first LBT threshold value is different than the second LBT threshold value.

In a fourth aspect alternatively or in addition to any of the first through third aspects, the first frequency spectrum is associated with a first RB set, and the second frequency spectrum is associated with a second RB set different than the first RB set.

In a fifth aspect alternatively or in addition to any of the first through fourth aspects, the first frequency spectrum is associated with a first plurality of RB sets, and the second frequency spectrum is associated with a second plurality of RB sets different than the first plurality of RB sets.

In a sixth aspect alternatively or in addition to any of the first through fifth aspects, the base station and the UE operate based on a wireless communication protocol that specifies a mapping table of index values to LBT threshold values, and the method includes determining, by the UE based on the mapping table, the plurality of LBT threshold values based on a particular index value indicated by the control message.

In a seventh aspect alternatively or in addition to any of the first through sixth aspects, the plurality of LBT threshold values corresponds to a particular row of the mapping table.

In an eighth aspect alternatively or in addition to any of the first through seventh aspects, the method includes receiving a configuration message configuring the UE with a mapping table of index values to LBT threshold values and determining, by the UE based on the mapping table, the plurality of LBT threshold values based on a particular index value indicated by the control message.

In a ninth aspect alternatively or in addition to any of the first through eighth aspects, the configuration message has a radio resource control (RRC) format.

In a tenth aspect alternatively or in addition to any of the first through ninth aspects, the control message includes a first index value indicating the first LBT threshold value and further includes a second index value indicating the second LBT threshold value.

In an eleventh aspect alternatively or in addition to any of the first through tenth aspects, the method further includes accessing, by the UE, a mapping table to determine the first LBT threshold value based on the first index value to and determine the second LBT threshold value based on the second index value.

In a twelfth aspect alternatively or in addition to any of the first through tenth aspects, the first index value includes a first number of bits, and the second index value includes a second number of bits.

In a thirteenth aspect alternatively or in addition to any of the first through twelfth aspects, the first number of bits indicates a first resolution associated with the first LBT threshold value, and the second number of bits indicates a second resolution associated with the second LBT threshold value.

In a fourteenth aspect alternatively or in addition to any of the first through thirteenth aspects, the control message has one of a downlink control information (DCI) 2_0 format, a radio resource control (RRC) format, or a medium access control (MAC) control element (MAC-CE) format.

In a fifteenth aspect alternatively or in addition to any of the first through fourteenth aspects, the first LBT threshold value is different than the second LBT threshold value, and wherein performing the transmission includes transmitting an uplink signal using both the first frequency spectrum and the second frequency spectrum.

In a sixteenth aspect alternatively or in addition to any of the first through fifteenth aspects, performing the LBT operation includes determining a first energy value associated with the first frequency spectrum and a second energy value associated with the second frequency spectrum, and the method includes determining success of the LBT operation based on detecting that the first energy value fails to satisfy the first LBT threshold value and that the second energy value fails to satisfy the second LBT threshold value.

In a seventeenth aspect alternatively or in addition to any of the first through sixteenth aspects, the method includes determining, by the UE, a composite LBT threshold value based on the plurality of LBT threshold values.

In an eighteenth aspect alternatively or in addition to any of the first through seventeenth aspects, the method includes determining the composite LBT threshold value includes identifying a maximum value of the plurality of LBT threshold values and selecting the maximum value as the composite LBT threshold value.

In a nineteenth aspect alternatively or in addition to any of the first through eighteenth aspects, determining the composite LBT threshold value includes identifying a minimum value of the plurality of LBT threshold values and selecting the minimum value as the composite LBT threshold value.

In a twentieth aspect alternatively or in addition to any of the first through nineteenth aspects, the composite LBT threshold value corresponds to an average of the plurality of LBT threshold values.

In a twenty-first aspect alternatively or in addition to any of the first through twentieth aspects, determining the composite LBT threshold value includes performing one or more operations based on a particular function of the plurality of LBT threshold values.

In a twenty-second aspect alternatively or in addition to any of the first through twenty-first aspects, the composite LBT threshold value corresponds to a predetermined LBT threshold value that is reserved for LBT operations associated with multiple different LBT threshold values.

In a twenty-third aspect alternatively or in addition to any of the first through twenty-second aspects, a non-transitory computer-readable medium stores instructions executable by a processor to perform operations. The operations include receiving, from a base station, a control message associated with a plurality of LBT threshold values including a first LBT threshold value and a second LBT threshold value. The first LBT threshold value is associated with a first frequency spectrum, and the second LBT threshold value is associated with a second frequency spectrum different than the first frequency spectrum. The operations further include performing an LBT operation based on the first LBT threshold value and the second LBT threshold value. The operations further include, based on the LBT operation, initiating a transmission using one or both of the first frequency spectrum or the second frequency spectrum.

In a twenty-fourth aspect alternatively or in addition to any of the first through twenty-third aspects, an apparatus includes a memory and one or more processors coupled to the memory. The one or more processors are configured to receive, from a base station, a control message associated with a plurality of LBT threshold values including a first LBT threshold value and a second LBT threshold value. The first LBT threshold value is associated with a first frequency spectrum, and the second LBT threshold value is associated with a second frequency spectrum different than the first frequency spectrum. The one or more processors are further configured to perform an LBT operation based on the first LBT threshold value and the second LBT threshold value and to initiate, based on the LBT operation, a transmission using one or both of the first frequency spectrum or the second frequency spectrum.

In a twenty-fifth aspect alternatively or in addition to any of the first through twenty-fourth aspects, an apparatus includes means for receiving, from a base station, a control message associated with a plurality of LBT threshold values including a first LBT threshold value and a second LBT threshold value. The first LBT threshold value is associated with a first frequency spectrum, and the second LBT threshold value is associated with a second frequency spectrum different than the first frequency spectrum. The apparatus further includes means for performing an LBT operation based on the first LBT threshold value and the second LBT threshold value and means for performing, based on the LBT operation, a transmission using one or both of the first frequency spectrum or the second frequency spectrum.

In a twenty-sixth aspect alternatively or in addition to any of the first through twenty-fifth aspects, a method of wireless communication includes determining, by a base station, that a first frequency spectrum is available for communication. The method further includes determining, by the base station, that a second frequency spectrum is available for communication. The second frequency spectrum is different than the first frequency spectrum. The method further includes transmitting, by the base station to a UE, a control message associated with a plurality of LBT threshold values including a first LBT threshold value and a second LBT threshold value. The first LBT threshold value is associated with the first frequency spectrum, and the second LBT threshold value is associated with the second frequency spectrum.

In a twenty-seventh aspect alternatively or in addition to any of the first through twenty-sixth aspects, the method includes determining the first LBT threshold value based at least in part on whether the first frequency spectrum is adjacent to a frequency spectrum scheduled for a downlink communication and further includes determining the second LBT threshold value based at least in part on whether the second frequency spectrum is adjacent to a frequency spectrum scheduled for a downlink communication.

In a twenty-eighth aspect alternatively or in addition to any of the first through twenty-seventh aspects, one of the first frequency spectrum or the second frequency spectrum is adjacent to a downlink frequency band, the other of the first frequency spectrum or the second frequency spectrum is non-adjacent to a downlink frequency band, and the first LBT threshold value is different than the second LBT threshold value.

In a twenty-ninth aspect alternatively or in addition to any of the first through twenty-eighth aspects, the method includes determining, by the base station, that a third frequency spectrum is unavailable for communication, and the plurality of LBT threshold values excludes any LBT threshold value associated with the third frequency spectrum.

In a thirtieth aspect alternatively or in addition to any of the first through twenty-ninth aspects, the base station and the UE operate based on a wireless communication protocol that specifies a mapping table of index values to LBT threshold values, and the UE determines, based on the mapping table, the plurality of LBT threshold values based on a particular index value indicated by the control message.

In a thirty-first aspect alternatively or in addition to any of the first through thirtieth aspects, the plurality of LBT threshold values corresponds to a particular row of the mapping table.

In a thirty-second aspect alternatively or in addition to any of the first through thirty-first aspects, the method includes transmitting a configuration message configuring the UE with a mapping table of index values to LBT threshold values, and the UE determines, based on the mapping table, the plurality of LBT threshold values based on a particular index value indicated by the control message.

In a thirty-third aspect alternatively or in addition to any of the first through thirty-second aspects, the configuration message has a radio resource control (RRC) format.

In a thirty-fourth aspect alternatively or in addition to any of the first through thirty-third aspects, the control message includes a first index value indicating the first LBT threshold value and further includes a second index value indicating the second LBT threshold value.

In a thirty-fifth aspect alternatively or in addition to any of the first through thirty-fourth aspects, the UE accesses a mapping table to determine the first LBT threshold value based on the first index value to and determine the second LBT threshold value based on the second index value.

In a thirty-sixth aspect alternatively or in addition to any of the first through thirty-fifth aspects, the first index value includes a first number of bits, and the second index value includes a second number of bits.

In a thirty-seventh aspect alternatively or in addition to any of the first through thirty-sixth aspects, the first number of bits indicates a first resolution associated with the first LBT threshold value, and the second number of bits indicates a second resolution associated with the second LBT threshold value.

In a thirty-eighth aspect alternatively or in addition to any of the first through thirty-seventh aspects, the control message has one of a downlink control information (DCI) 2_0 format, a radio resource control (RRC) format, or a medium access control (MAC) control element (MAC-CE) format.

In a thirty-ninth aspect alternatively or in addition to any of the first through thirty-eighth aspects, a non-transitory computer-readable medium stores instructions executable by a processor to perform operations. The operations include determining that a first frequency spectrum is available for communication and determining that a second frequency spectrum is available for communication. The second frequency spectrum is different than the first frequency spectrum. The operations further include initiating transmission, to a UE, of a control message associated with a plurality of LBT threshold values including a first LBT threshold value and a second LBT threshold value. The first LBT threshold value is associated with the first frequency spectrum, and the second LBT threshold value is associated with the second frequency spectrum.

In a fortieth aspect alternatively or in addition to any of the first through thirty-ninth aspects, an apparatus includes a memory and one or more processors coupled to the memory. The one or more processors are configured to determine that a first frequency spectrum is available for communication and to determine that a second frequency spectrum is available for communication. The second frequency spectrum is different than the first frequency spectrum. The one or more processors are further configured to initiate transmission, to a UE, of a control message associated with a plurality of LBT threshold values including a first LBT threshold value and a second LBT threshold value. The first LBT threshold value is associated with the first frequency spectrum, and the second LBT threshold value is associated with the second frequency spectrum.

In a forty-first aspect alternatively or in addition to any of the first through fortieth aspects, an apparatus includes means for determining that a first frequency spectrum is available for communication and for determining that a second frequency spectrum is available for communication, wherein the second frequency spectrum is different than the first frequency spectrum. The apparatus further includes means for transmitting, a UE, a control message associated with a plurality of LBT threshold values including a first LBT threshold value and a second LBT threshold value. The first LBT threshold value is associated with the first frequency spectrum, and the second LBT threshold value is associated with the second frequency spectrum.

In a forty-second aspect alternatively or in addition to one or more of the first through forty-first aspects, an apparatus includes a receiver configured to receive, from a base station, a control message associated with a plurality of LBT threshold values including a first LBT threshold value and a second LBT threshold value. The first LBT threshold value is associated with a first frequency spectrum, and the second LBT threshold value is associated with a second frequency spectrum different than the first frequency spectrum. The apparatus further includes a transmitter configured to initiate a transmission using one or both of the first frequency spectrum or the second frequency spectrum. The transmission is based on an LBT operation that is based on the first LBT threshold value and the second LBT threshold value.

In a forty-third aspect alternatively or in addition to one or more of the first through forty-second aspects, the configuration message has a radio resource control (RRC) format, and the control message has one of a downlink control information (DCI) 2_0 format, an RRC format, or a medium access control (MAC) control element (MAC-CE) format.

In a forty-fourth aspect alternatively or in addition to one or more of the first through forty-third aspects, the control message includes a first index value indicating the first LBT threshold value and further includes a second index value indicating the second LBT threshold value, and the apparatus includes a memory configured to store a mapping table indicating the first LBT threshold value, the first index value, the second LBT threshold value, and the second index value.

In a forty-fifth aspect alternatively or in addition to one or more of the first through forty-fifth aspects, the first index value includes a first number of bits indicating a first resolution associated with the first LBT threshold value, and the second index value includes a second number of bits indicating a second resolution associated with the second LBT threshold value.

In a forty-sixth aspect alternatively or in addition to one or more of the first through forty-fifth aspects, a method of wireless communication includes transmitting, by a base station to a UE, a control message associated with a plurality of LBT threshold values including a first LBT threshold value and a second LBT threshold value. The first LBT threshold value is associated with a first frequency spectrum, and the second LBT threshold value is associated with a second frequency spectrum different than the first frequency spectrum. The method further includes receiving, from the UE, a transmission using one or both of the first frequency spectrum or the second frequency spectrum. The transmission is based on an LBT operation that is based on the first LBT threshold value and the second LBT threshold value.

In a forty-seventh aspect alternatively or in addition to one or more of the first through forty-sixth aspects, the method includes determining the first LBT threshold value based at least in part on whether the first frequency spectrum is adjacent to a frequency spectrum scheduled for a downlink communication and further includes determining the second LBT threshold value based at least in part on whether the second frequency spectrum is adjacent to a frequency spectrum scheduled for a downlink communication.

In a forty-eighth aspect alternatively or in addition to one or more of the first through forty-seventh aspects, one of the first frequency spectrum or the second frequency spectrum is adjacent to a downlink frequency band, the other of the first frequency spectrum or the second frequency spectrum is non-adjacent to a downlink frequency band, and the first LBT threshold value is different than the second LBT threshold value.

In a forty-ninth aspect alternatively or in addition to one or more of the first through forty-eighth aspects, the method includes determining, by the base station, that a third frequency spectrum is unavailable for communication, wherein the plurality of LBT threshold values excludes any LBT threshold value associated with the third frequency spectrum.

In a fiftieth aspect alternatively or in addition to one or more of the first through forty-ninth aspects, the base station and the UE operate based on a wireless communication protocol that specifies a mapping table of index values to LBT threshold values, and the UE determines, based on the mapping table, the plurality of LBT threshold values based on a particular index value indicated by the control message.

In a fifty-first aspect alternatively or in addition to one or more of the first through fiftieth aspects, the plurality of LBT threshold values corresponds to a particular row of the mapping table.

In a fifty-second aspect alternatively or in addition to one or more of the first through fifty-first aspects, an apparatus includes a transmitter configured to transmit, to a UE, a control message associated with a plurality of LBT threshold values including a first LBT threshold value and a second LBT threshold value. The first LBT threshold value is associated with a first frequency spectrum, and the second LBT threshold value is associated with a second frequency spectrum different than the first frequency spectrum. The apparatus further includes a receiver configured to receive, from the UE, a transmission using one or both of the first frequency spectrum or the second frequency spectrum. The transmission is based on an LBT operation that is based on the first LBT threshold value and the second LBT threshold value.

In a fifty-third aspect alternatively or in addition to one or more of the first through fifty-second aspects, the transmitter is further configured to transmit a configuration message configuring the UE with a mapping table of index values to LBT threshold values, and the UE determines, based on the mapping table, the plurality of LBT threshold values based on a particular index value indicated by the control message.

In a fifty-fourth aspect alternatively or in addition to one or more of the first through fifty-third aspects, the control message includes a first index value indicating the first LBT threshold value and further includes a second index value indicating the second LBT threshold value.

Those of skill in the art would understand that information and signals may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof. The functional blocks and operations described herein may be implemented using one or more processors, electronics devices, hardware devices, electronics components, logical circuits, memories, software codes, firmware codes, etc., or any combination thereof.

Those of skill would further appreciate that the various illustrative logical blocks, devices, circuits, and operations described herein may be implemented using electronic hardware, computer software, or combinations of both. To illustrate, various components, blocks, devices, circuits, and operations have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design parameters of the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the disclosure. Skilled artisans will also readily recognize that the order or combination of components, methods, or interactions that are described herein are merely examples and that the components, methods, or interactions of the various aspects of the disclosure may be combined or performed in ways other than those illustrated and described herein.

In one or more exemplary designs, the functions described may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable storage media may be any available media that can be accessed by a general purpose or special purpose computer. By way of example, and not limitation, such computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other 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. Disk and disc, as used herein, includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and blu-ray disc where disks usually 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.