New radio (NR) shared spectrum (NR-SS) listen before talk (LBT) gap optimizations are disclosed in which an indication, such as the preemption indicator, may provide an indication of a communications gap, in which preemptive communications may occur, to a user equipment (UE) currently engaged in communications, whether the preemptive communications are to another UE or network node or through different signal channels. The gap and preemptive communication may be measured in full symbol lengths, sub-symbol lengths, or interlaces. The communication gap may provide sufficient resources for the preempting node to adequately obtain the shared channel via listen before talk (LBT) procedures, and for the original UE to resume communications after the gap. The communication gap may also be optimally configured in order to provide both the UE and preempting node as much communication resources as possible within the scheduled communication opportunities.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of Indian Provisional Patent Application No. 201841002680, entitled, “NR-SS LBT GAP OPTIMIZATIONS,” filed on Jan. 23, 2018, which is expressly incorporated by reference herein in its entirety.

BACKGROUND

Field

Aspects of the present disclosure relate generally to wireless communication systems, and more particularly, to new radio (NR) shared spectrum (NR-SS) listen before talk (LBT) gap optimizations.

Background

SUMMARY

in one aspect of the disclosure, a method of Wireless communication, includes receiving, at a UE, an indicator identifying a communication gap preempting a current communication between the UE and a serving base station, identifying, by the UE, a beginning, an end, and a length of the communication gap, puncturing, by the UE, the current communication at the beginning of the communication gap, and resuming, by the UE, the current communication after the length of the communication gap.

In an additional aspect of the disclosure, a method of wireless communication includes receiving, by a UE, a preemptive grant for preemptive communications with a serving base station during current communications on a shared communication network, wherein the preemptive grant includes at least a sub-symbol offset for a beginning of the preemptive communications, and a length of the preemptive communications, determining, by the UE, whether to perform a listen before talk (LRT) procedure on the shared communication channel, and participating, by the UE, in the preemptive communications according to the preemptive grant.

In an additional aspect of the disclosure, a method of wireless communication includes receiving, by a UE, a preemptive grant for preemptive downlink communications with a serving base station during current communications on a shared communication network, attempting, by the UE, to decode detected signals at each symbol boundary according to a plurality of decoding hypotheses, and receiving, at the UE the preemptive downlink communications in response to successfully decoding the detected signals.

In an additional aspect of the disclosure, an apparatus configured for wireless communications includes means for receiving, at a UE, an indicator identifying a communication gap preempting a current communication between the UE and a serving base station, means for identifying, by the UE, a beginning, an end, and a length of the communication gap, means for puncturing, by the UE, the current communication at the beginning of the communication gap, and means for resuming, by the UE, the current communication after the length of the communication gap.

In an additional aspect of the disclosure, an apparatus configured for wireless communications includes means for receiving, by a UE, a preemptive grant for preemptive communications with a serving base station during current communications on a shared communication network, wherein the preemptive grant includes at least a sub-symbol offset for a beginning of the preemptive communications, and a length of the preemptive communications, means for determining, by the UE, whether to perform a LBT procedure on the shared communication channel, and means for participating, by the UE, in the preemptive communications according to the preemptive grant.

In an additional aspect of the disclosure, an apparatus configured for wireless communications includes means for receiving, by a UE, a preemptive grant for preemptive downlink communications with a serving base station during current communications on a shared communication network, means for attempting, by the UE, to decode detected signals at each symbol boundary according to a plurality of decoding hypotheses, and means for receiving, at the UE the preemptive downlink communications in response to successfully decoding the detected signals.

In an additional aspect of the disclosure, a non-transitory computer-readable medium having program code recorded thereon. The program code further includes code to receive, at a UE, an indicator identifying a communication gap preempting a current communication between the UE and a serving base station, code to identify, by the UE, a beginning, an end, and a length of the communication gap, code to puncture, by the UE, the current communication at the beginning of the communication gap, and code to resume, by the UE, the current communication after the length of the communication gap.

In an additional aspect of the disclosure, a non-transitory computer-readable medium having program code recorded thereon. The program code further includes code to receive, by a UE, a preemptive grant for preemptive communications with a serving base station during current communications on a shared communication network, wherein the preemptive grant includes at least a sub-symbol offset for a beginning of the preemptive communications, and a length of the preemptive communications, code to determine, by the UE, whether to perform a LBT procedure on the shared communication channel, and code to participate, by the UE, in the preemptive communications according to the preemptive grant.

In an additional aspect of the disclosure, a non-transitory computer-readable medium having program code recorded thereon. The program code further includes code to receive, by a UE, a preemptive grant for preemptive downlink communications with a serving base station during current communications on a shared communication network, code to attempt, by the UE, to decode detected signals at each symbol boundary according to a plurality of decoding hypotheses, and code to receive, at the UE the preemptive downlink communications in response to successfully decoding the detected signals.

In an additional aspect of the disclosure, an apparatus configured for wireless communication is disclosed. The apparatus includes at least one processor, and a memory coupled to the processor. The processor is configured to receive, at a UE, an indicator identifying a communication gap preempting a current communication between the UE and a serving base station, to identify, by the UE, a beginning, an end, and a length of the communication gap, to puncture, by the UE, the current communication at the beginning of the communication gap, and to resume, by the LIE, the current communication after the length of the communication gap.

In an additional aspect of the disclosure, an apparatus configured for wireless communication is disclosed. The apparatus includes at least one processor, and a memory coupled to the processor. The processor is configured to receive, by a UE, a preemptive grant for preemptive communications with a serving base station during current communications on a shared communication network, wherein the preemptive grant includes at least a sub-symbol offset for a beginning of the preemptive communications, and a length of the preemptive communications, to determine, by the LIE, whether to perform a LET procedure on the shared communication channel, and to participate, by the UE, in the preemptive communications according to the preemptive grant.

In an additional aspect of the disclosure, an apparatus configured for wireless communication is disclosed. The apparatus includes at least one processor, and a memory coupled to the processor. The processor is configured to receive, by a UE, a preemptive grant for preemptive downlink communications with a serving base station during current communications on a shared communication network, to attempt, by the UE, to decode detected signals at each symbol boundary according to a plurality of decoding hypotheses, and to receive, at the UE the preemptive downlink communications in response to successfully decoding the detected signals.

DETAILED DESCRIPTION

FIG. 1is a block diagram illustrating 5G network100including various base stations and UEs configured 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), wireless modern, 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) 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 UP115, which may be one of the base station and one of the UEs inFIG. 1. 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. The controllers/processor280and/or other processors and modules at the UE115may also perform or direct the execution of the functional blocks illustrated inFIGS. 4, 6, and 9, and/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.

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 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.

The timing diagram300includes a superframe305, which may represent a fixed duration of time (e.g., 20 ms). 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-TNT for Operator A (e.g., G-INT-OpA). Similarly, resources335-bmay be prioritized for Operator B, resources335-cmay 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, 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.

In some examples, a network operating entity May intend not to use a particular O-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 a uplink transmission. In some embodiments, 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 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.

Uplink (UL) mini-slot in NR operations may involve scheduling a short preemptive duration for a UE that has preemptive communications to make. The UE having the preemptive communications may be referred to herein as a UE2, while the UE performing the on-going communications that are preempted may be referred to as a UE1. Preemptive communications may include a variety of different communications that have been given a higher priority than the on-going communications of another UE. For example, the preemptive communications may include ultra-reliable low-latency communications (URLLC), communications from a higher priority UE, and the like. The UE1may be participating in lower-priority communications, including enhanced mobile broadband (eMBB) communications, or communications from a UE that has a lower priority than the UE2.

Also applicable to URLLC may be to allow high-priority data of UE2in the middle of UE1transmissions. The scheduling of the URLLC data preemption may be performed through an anchor carrier in an enhanced license assisted access (eLAA) deployment with transmissions in an unlicensed carriers may be in addition to parallel transmissions in the licensed carrier. However, when considering NR shared spectrum (NR-SS) operations, the UE2will perform an LBT procedure before it can transmit on the shared communication channel. Because it is attempting to transmit within the current communications of UE1, UE2would detect the UE1signal and, thus, not transmit because of a failed LBT. Similarly, for UE1, when it transmits after the scheduled communication gap for the preemptive UE2communications, UE1will also perform LBT on the shared channel. If there is no gap between the UE2transmissions and the UE1resuming transmission, the UE1would detect the UE2signal and also not transmit because of a failed LBT. Various aspect of the present disclosure are directed to an LBT gap being indicated through a preemption indicator (PI) communicated by the serving base station.

FIG. 4is a block diagram illustrating example blocks executed to implement one aspect of the present disclosure. The example blocks will also be described with respect to UE115as illustrated inFIG. 12.FIG. 12is a block diagram illustrating UE115configured according to one aspect of the present disclosure. UE115includes the structure, hardware, and components as illustrated for UE115ofFIG. 2. For example, UE115includes controller/processor280, which operates to execute logic or computer instructions stored in memory282, as well as controlling the components of UE115that provide the features and functionality of UE115. UE115, under control of controller/processor280, transmits and receives signals via wireless radios1200a-rand antennas252a-r. Wireless radios1200a-rincludes various components and hardware, as illustrated inFIG. 2for UE115, including modulator/demodulators254a-r, MIMO detector256, receive processor258, transmit processor264, and TX MIMO processor266.

At block400, a UE1receives an indicator identifying a communication gap preempting a current communication between the UE1and a serving base station. For example, a UE, such as UE115, may receive a PI from the serving base station that identifies a communication gap within the current communications of UE115. PI is received from the serving base station via antennas252a-rand wireless radios1200a-rand stored, under control of controller/processor280, in memory282at PI information1201. For purposes of the example aspect illustrated inFIG. 4, UE115may operate as an eMBB UE.

At block401, the UE1identifies a beginning, an end, and a length of the communication gap. The information contained within PI information1201allows UE115, under control of controller/processor280, to determine which slots, symbols, or interlaces to puncture to accommodate a preemptive communication from a neighboring node, which may be another eMBB UE, a neighboring priority UE, such as a URLLC UE, a base station, or the like. In FDM operations the communication gap may be defined by identified frequency, which may be one or more bandwidth parts (BWP) or frequency interlaces. The information contained within PI information1201may define the exact resources for UE115to puncture or may provide information on the resources that the preemptive communication will use which allows UE115to determine the resources that it will puncture to provide the communication gap. In example implementations, the gap would be sufficient to allow the intervening node to perform an LBT before transmitting.

At block402, the UE1punctures the current communication at the beginning of the communication gap. With the details of the communication gap determined by UE115, UE115, under control of controller/processor280, executes transmit puncturing1202, in memory282. The execution environment of transmit puncturing1202provides for UE115to stop scheduled transmissions to create a communication gap for intervening preemptive communications. UE115, within the execution environment of transmit puncturing1202punctures its current communications to exit the shared medium and allow the preemptive node to transmit.

At block403, the UE1resumes the current communication after the length of the communication gap. Once the time for the communication gap has passed, UE115may resume the current communications. For example, UP115may resume eMBB communications via wireless radios1200a-rand antennas252a-r. Various example aspects may provide for UE115to perform an LBT procedure prior to resuming communications on the shared channel. In such aspect, UE115would, under control of controller/processor280, execute LBT logic1205. The execution environment of LBT logic1205allows UE115to perform LBT of a given shared communication channel.

FIGS. 5A and 5Bare block diagrams illustrating base station105and UE1and UE2, configured according to aspects of the present disclosure. According to the various aspects of the present disclosure, LBT gaps may be introduced both before and after the preemptive communications where time division multiplex (TDM) operations are conducted (FIG. 5A), or on the beginning side of the preemptive communication if there are no UEs that are purely in TDM operations50and in frequency division multiplex (FDM) operations51(FIG. 5B). For URLLC, the NR preemption indicator (PI) can be used to indicate the number of UE1symbol holes to be punctured for the UE2URLLC transmission. In TDM operations50, UE1receives the PI from base station105, which identifies to UE1to puncture communication gap resources502during current communications500. UR1symbol holes are punctured in communication gap resources502for the duration of the UE2transmission503plus an extra number of symbols for a guard period (GP), which can be a partial symbol. UE1would resume current communications504after the second GP.

In FDM operations51, UE1receives the PI from base station105to determine the communication gap resources506. FDM operations51would only use a single or partial punctured symbol at the beginning of communication gap resources506for UE2to perform LBT. Upon successful LBT, UE2would perform preemptive communications507covering the frequency identified in the FDM grant from base station105. UE1may continue current communications508in different frequencies during preemptive communications507and then over the allocated frequencies after preemptive communications507.

It should be noted that the definition of preempted resources in NR may be modified to allow for such LBT gaps. For example, NR may only allow preemption sizes of 2/7 symbols that may be the supported slot sizes for mini-slots/URLLC. However, for NR-SS the supported preemption sizes may be changed in order to accommodate the LBT gaps.

In NR, the PI generally indicates the resources that the eMBB UE (UE1) will puncture for the communication gap. The PI indication in NR has two formats: (1) a 14 bit bitmap for the time domain symbols to puncture; and (2) a 7×2 bit bitmap for sets of OFDM symbols in time×2 for puncturing in the frequency domain (bandwidth part). Note that in both formats, each bit of the bitmap corresponds to a group of OFDM symbols.

It should be noted that for NR-SS operations, the frequency domain resource indication may be changed to a set of interlaces, instead of bandwidth parts, as allocation will likely be done in units of interlaces.

The information contained within the PI may be configured in multiple formats. In a first optional aspect, the PI indicates the resources that the eMBB UE (UE1) will puncture for the communication gap. The serving base station may consider all the gaps needed for the preemptive transmission and capture those gap resource in the bitmap of the P1. When the SCS configuration is different for the eMBB UE (UE1) and the URLLC UE (UE2), the number of symbols may not perfectly align. Because each bit corresponds to a group of symbols, even though only one group of symbols may be allocated for the preemptive communication, the PI will create an LBT gap by blanking/puncturing the entire group of symbols prior to and after the symbol group(s) used for the preemptive transmission.

In a second optional aspect, the P1may indicate the resources (e.g., SCS and/or time frequency resources) to be used by the URLLC UEs (UE2). In such aspects, the eMBB UE (UE1) uses its own SCS and the LBT requirement to determine how much additional time/frequency resources should be punctured to create the applicable communication gap. For example, in a scenario where 2 symbols should be punctured for the preemptive communication with SCS of 15 KHz, and for an eMBB UP (UE1) having an SCS of 15 KHz, there are 14 uplink symbols in 1 ms. Therefore, the communication gap should be 4 symbols (2 URLLC symbols+2 gap symbols). If the UE1has an SCS of 30 KHz, there are 28 uplink symbols in 1 ms, which would mean that 6 symbols should be punctured for the communication gap. It should be noted that the SCS is the inverse of symbol length. Thus, as the SCS becomes larger, the symbol length becomes inversely shorter, and vice versa. In such an example scenario, each URLLC symbol having an SCS of 15 KHz would span 2 symbols of the UE1having an SCS of 30 KHz. Two symbols of gap before and after the preemptive communication may be used for LBT procedure. One symbol with 30 KHz SCS may also be sufficient for an LBT gap.

FIG. 6is a block diagram illustrating example blocks executed to implement one aspect of the present disclosure. When the UE2(URLLC UE) monitors for URLLC data, it should receive the data regardless of how the transmission switch occurs. In the illustrated aspect, the UE2may attempt multiple hypotheses for each OFDM symbol boundary. The example blocks will also be described with respect to UE115as illustrated inFIG. 12. At block600, a UE2receives a preemptive grant for preemptive downlink communications with a serving base station during current communications on a shared communication network. For example, a priority UE, such as UE115, may receive a downlink grant via antennas252a-rand wireless radios1200a-ridentifying the preemptive communication during the communications of a neighboring non-priority UE. For purposes of the example illustrated inFIG. 6, UP115operates as a priority UE, such as a URLLC UE.

At block601a, the UE2attempts to decode detected signals at each symbol boundary according to a plurality of decoding hypotheses. Because the communication channel is shared, there is no guarantee that the serving base station will secure the channel. In order to receive the preemptive downlink communication, UE115will attempt multiple hypotheses at each OFDM symbol boundary. UE115, under control of controller/processor280accesses the multiple hypotheses at decoding processes1204, stored in memory282. The hypotheses are then used by decoders within wireless radios1200a-rto attempt to decode the received signals. Block601ais a first alternative block that may be executed in various aspects of the present disclosure.

In alternative to block601a, at block601b, the UE2identifies, from the preemptive grant, a sub-symbol offset to decode detected signals. Where the example aspect includes sub-symbol operations, UE115may detect the sub-symbol offset, which may be included in preemptive grant1203, stored in memory282. UE115would use the sub-symbol offset to decode signals detected and received from antennas252a-rand1200a-r.

At block602, the UE2receives the preemptive downlink communications in response to successfully decoding the detected signals. UE115receives the preemptive downlink communications via antennas252a-rand wireless radios1200a-r. If downlink transmissions are made, UE115may successfully decode the transmissions using one of the hypotheses from decoding processes1204in decoders located within wireless radios1200a-r.

FIGS. 7A and 7Bare block diagrams illustrating base station105and UE1and UE2configured according to one aspect of the present disclosure. Additional aspects of the present disclosure provide for sub-symbol offsets for OFDM symbols that provide LBT gaps having sub-symbol shifts. In order to reduce the overhead, sub-symbol gaps and provided instead of full symbol gaps.FIG. 7Aillustrates TDM operations70, in which sub-symbol gaps are provided on both sides of the preemptive communications from UE2. UE1receives an indicator from the serving base station (e.g., PI) that identifies communication gap701. According to the present aspect, the base station assigns a sub-symbol offset to preemptive communications702by UE2. The sub-symbol offset shifts the preemptive transmission resources off of the symbol boundary. Thus, as UE1performs current communication700, it punctures three symbols for communication gap701to accommodate the sub-symbol shifted preemptive communications702. The resulting gaps before and after preemptive communications702are less than a full symbol in length, which conserves resources over a full-symbol gap. UE1may resume current communications703after the second gap, which may occur with or without an LBT, depending on the configuration and characteristics, such as the length of communication gap701or the length of the second gap.

FIG. 7Billustrates FDM operations71, in which a sub-symbol gap is defined at the beginning of communication gap705prior to preemptive communication706of UE2. UE1receives the PI from base station105indicating the parameters for communication gap705. UE1punctures the current communications creating a sub-symbol gap without communications for UE2to perform LBT prior to preemptive transmission706. UE1may then transmit dummy transmission707in the sub-symbol after UE2completes preemptive transmission706. In the sub-symbol offset designs illustrated inFIGS. 7A and 7B, UE2transmission symbols are not symbol aligned with the original frame structure of current communications704of UE1. However, it reduces the amount of wasted resources for gaps in the pure TDM case (FIG. 7A). After dummy transmission707, UE1may resume current communications708.

FIGS. 8A and 8Bare block diagrams illustrating base station105and UE1and UE2configured according to one aspect of the present disclosure. The sub-carrier spacing (SCS) of the two different UEs (UE1and UE2) may be different.FIG. 8Aillustrates a shared communication channel80in which UE2is configured with a larger SCS than UE1and the OFDM symbols of the preemptive communications of UE2are aligned with the symbols of the current communications of UE1. Accordingly, the symbol size of UE1transmissions (UE symbol x, symbol x+1, x+5) are larger than the symbol size of UE2transmissions (UE21-4).

FIG. 8Billustrates a shared communication channel81, where the preemptive communications are at a sub-symbol offset. As indicated above, the different SCS configurations allow a shorter symbol length for the UE2communications. However, by using the sub-symbol offset, UE2is able to complete more transmission symbols (UE21-5) of URLLC uplink data over the same communication gap size (communication gap801) as the full symbol gap (communication gap800) illustrated inFIG. 8A.

For uplink mini-slots, the downlink control information (DCI) may schedule the time domain resources for the UE2preemptive communication in the middle of current communications of the UE1. The sub-symbol level resource control may be any portion of the full symbol length. The TDM resource allocation in the DCI can also indicate the sub-symbol level resource allocation for the UE2preemptive communication. For large SCS the symbol duration becomes smaller and, hence, the benefits for the sub-symbol offset option may be reduced.

It should be noted that when the UE2preemptive communication is based on autonomous uplink (AUL) operations, the AUL radio resource control (RRCj) configuration/activation/information may be determined from the PI, which may be used to determine the offset for the symbol boundaries.

FIG. 9is a block diagram illustrating example blocks executed to implement one aspect of the present disclosure. The example blocks will also be described with respect to UE115as illustrated inFIG. 12. At block900, a UE2receives a preemptive grant for preemptive communications with a serving base station during current communications on a shared communication network, wherein the preemptive grant identifies a sub-symbol offset for the preemptive communications. When preemptive communications are available (e.g., uplink/downlink) UE115may receive a communications grant for the preemptive communications from the serving base station via antennas252a-rand wireless radios1200a-r. For purposes of the example aspect illustrated inFIG. 9, UE115may operate as the priority UE (e.g., UE2).

At block901, the UE2determines whether to perform an LBT procedure on the shared communication channel. UE115executes, under control of controller/processor280, LBT logic1205, stored in memory282. Within the execution environment of LBT logic1205, UE115may determine whether to perform LBT prior to transmissions. LBT for the preemptive communications may or may not be performed, depending on the configuration of the network operations as well as certain characteristics existing for the communication opportunity. For example, in certain aspects, UE115may always perform LIST during the first gap prior to the preemptive transmission. Additional aspects may provide for no LBT when certain conditions are satisfied. For example, no LIST may be necessary if the preemptive transmission may occur during the transmission opportunity of the serving base station. Because the base station has reserved the shared channel for a certain standard period, if the preemptive transmissions were to occur during that transmission opportunity, there would be no need to perform LBT. Additionally, whether or not an LBT should be performed may be determined based on the size of the gap between the start of the punctured resources of communication gap and the beginning of the preemptive communications. A gap exceeding a predetermined threshold may trigger UE115to perform LBT, while the gap being within the predetermined threshold would allow UE115to perform the preemptive transmission without LBT. A further aspect provides for the serving base station to signal whether or not LBT should be performed by UE115.

At block902, the UE2participates in the preemptive communications according to the preemptive grant. Once the LBT has either been successfully performed or the determination made that no LBT is needed, as provided within the execution environment of LBT logic1205, UE115may participate in the preemptive communication as configured in the grant via wireless radios1200a-rand antennas252a-r.

As the communication gap and preemptive communications may be configured with sub-symbol resources, the participating network nodes may use mini-symbols to communicate according to various aspect of the present disclosure.

FIG. 10is a block diagram illustrating base station105, UE1, and UE2configured according to one aspect of the present disclosure. According to the illustrated examples, mini symbols, having different SCS, may be used in order to reduce LBT gaps. Communication stream1000illustrates a sub-symbol offset for communication gap1002and provides for to receive a dynamic change in SCS configuration in the PI. The dynamic SCS change allows UE1to continue transmissions1003prior to the sub-symbol gaps before and after the preemptive communication of UE2using a mini-symbol defined by the changed SCS. Communication stream1001illustrates a sub-symbol offset for communication gap1004and provides for both UE1to receive the dynamic SCS change in a PI and UE2to receive the dynamic SCS configuration within the URLLC grant. The dynamic change in SCS allows for UE1to transmit1005in a mini-symbol prior to the first LBT gap before the preemptive transmission of UE2, and allows UE2to transmit1005a mini-symbol prior to the ending sub-symbol gap where UE1may perform LBT to resume current communications.

In an additional aspect that may be illustrated byFIG. 10, even though UE1(the eMBB UE) is shown to create sub-symbol gaps, UE1may be allowed to transmit for portion of the symbol to avoid other UEs obtaining access to the medium and leaving just the minimum gap to enable UE2a successful LBT. UE1will have knowledge of UE2and its LBT operations, in order to determine the minimum gap that still allows UE2to successfully complete the LBT procedure. Similarly, although UE2is shown to have the sub-symbol to do the measurement, its transmission aligns to the mini-slot or URLCC symbol boundary. UE2may perform the LBT procedure prior to the mini-slot boundary and start transmitting dummy signals to reserve access to the shared communication channel. For example, if UE1does not transmit at1005, UE2may perform LBT and begin transmitting channel reserving signals at1005prior to the scheduled LBT mini-slot. Once the scheduled resource arrives, UE2may then begin the preemptive communication (UE2symbol1, symbol2). Additionally in the sub-symbol that UE2leaves a gap at the end of the preemptive communication, UE2may determine the minimum gap for UE to perform a successful LBT. UE2transmits for more time and leaves enough gap for UE1to do LBT successfully. As above, UE2would have information on UE1and its LET operations in order to determine the minimum gap for UE1LBT.

Aspects of the present disclosure may be used for various preemptive communications. For example, the sub-symbol start aspect may be used for changing uplink transmissions between two UEs; switching to an uplink transmission during downlink transmissions of other UEs; and switching to a downlink transmission during uplink transmissions of other UEs. When URLLC downlink transmission are scheduled between ongoing downlink transmissions of another UE, the sub-symbol gap would actually add overhead. Therefore, because the base station has already secured the medium, there is no need to leave a gap between downlink transmissions. It should be noted that a downlink-to-downlink gap (full symbol or sub-symbol) may still be necessary when communications are using mmWave with a directional LBT.

From perspective of UE2monitoring URLLC downlink data, the UE2should be able to receive data independently of whether the preemptive communication switching to downlink happens during the uplink of other UEs (in which case there may be a sub-symbol offset) or when it is in between ongoing downlink transmissions (no sub-symbol offsets). As illustrated inFIG. 6, UE2may attempt multiple hypotheses for the OFDM symbol boundary in order to receive the URLLC downlink transmission. Alternatively, UE2may receive a signal (e.g., specific or common DCI) that identifies the subframe structure. UE2may then know the offset at which it should attempt to decode and receive the data at the symbol/sub-symbol boundary.

FIGS. 11A and 11Bare block diagrams illustrating base station105, UE1, and UE2configured according to aspects of the present disclosure. Although the various aspect apply in the context of multiplexing a UE2uplink mini-slot communications in between other uplink transmissions, the various aspects of the present disclosure may be applicable in multiplexing other channels of a UE or base station in between transmissions of other UEs such as multiplexing sounding reference signal (SRS), acknowledgment (ACK), PUCCH, channel state information reference signals (CSI-RS), TRS, and the like, in between back to back PUSCH of other UEs (FIG. 11A). These sub-symbol level resource allocations can be absorbed into the time domain resource allocation field of the DCI, or can be semi-statically signaled (e.g., RRC), or implicitly signaled. For example, in communications over shared communication channel1100, uplink channels from UE1may be allocated using sub-symbol offsets to reduce communication gaps1104and1108for the uplink communications from UE1. Base station105transmits PDCCH1102,1106,1110and PDSCH1103and1107using shared communication channel1100. When UE1is assigned to transmit PUCCH1105and1108, a sub-symbol offset is used to offset alignment of PUCCH1105and1108. The sub-symbol offset conserves resources by providing communication gaps1104and1108by base station105of two symbols, instead of four, in which a sub-symbol length may be available for UE1to perform LBT prior to transmitting PUCCH1105and1108. An implicit signaling may provide no sub-symbol offset on downlink-to-downlink communications, and a sub-symbol offset on a downlink-to-other communication.

Additional aspects of the sub-symbol offset may apply for different direction channels transmitted between other communications to the same UE (FIG. 11B). For example, base station105transmits PI over shared communication channel1101to UE1during PDCCH1111identifying a communication gap1113between current communications PUSCH1112and1115for a priority UE, such as UE2, to transmit its SRS1114. The sub-symbol offset allows for communication gap1113to provide sub-symbol gaps before and after SRS1114.

As disclosed above, the LBT gaps for URLLC/uplink mini-slot introduce overhead. Various LBT options may be configured for UE2transmission of mini-slot/URLLC data. For example, LBT may be always performed or not performed in some cases. Where the entirety of the scheduled preemptive communication lies within the transmission opportunity secured by the base station, the UE2may elect not to perform an LBT procedure. UE2may determine this based on the length/SCS of the URLLC data, and the gap between start of the URLLC data and the puncture pattern start indicated in the PI. Additionally, the URLLC grant may also indicate whether the UE2should perform LBT.

For the eMBB UE (UE1) leaving the pre-emption gaps, the UE1may always perform LBT before resuming communication for both FDM/TDM, may not be required to perform LBT before resuming transmission for both FDM/TDM, may not be required to perform LBT before resuming transmission for FDM, but may perform LBT for TDM, possibly based on the duration of the pre-emption. For example, the determination of whether the UE1performs LBT may also depend on the SCS/number of contiguous blanked symbols/blanking time in PI. If the size of the gap exceeds a predetermined threshold, then the UE1would perform LBT. Alternatively, the PI or other control signaling (e.g., DCI) may explicitly indicate whether UE1should perform LBT or not after the gaps.

The guard period used in NR-SS during uplink mini-slot or URLLC transitions for performing LBT may be indicated to the UE2. The NR URLLC PI can be used to leave the required number of symbol holes punctured for FDM/TDM. Sub-symbol level scheduling can be introduced for the URLLC/mini-slot UE (UE2) to reduce the LBT gap overhead. This can be used for the UE2(Mini-slot/URLLC UE). The sub-symbol scheduling for UE2can be part of the DCI time domain resource scheduling. This can also be achieved by increasing the SCS for UE2and scheduling starting odd symbol. The sub-symbol level scheduling of the various aspects can also be used in NR-SS for other channels like PUCCH, SRS, ACK, etc. This sub-symbol level scheduling helps to reduce the LBT gap overhead and increase the chances of acquiring the channel. The LBT gaps for URLLC transmission/eMBB UE resuming transmission may be based on the length of blanking time/indicated in DCI etc. Combination of the solutions are of course allowed as well.