Control information update for dynamic time-division duplexing (TDD)

Wireless communications systems and methods related to updating control information based on medium sensing are provided. A first wireless communication device communicates with a second wireless communication device, a first transmission grant for a transmission opportunity (TXOP) in a frequency band. The first wireless communication device performs medium sensing for the TXOP. The performing the medium sensing includes detecting a reservation signal for the TXOP. The first wireless communication device transmits, to the second wireless communication device, an updated transmission grant for the TXOP based on at least the first transmission grant and the medium sensing. The first wireless communication device transmits, to the second wireless communication device in the frequency band, data during the TXOP based on the updated transmission grant.

TECHNICAL FIELD

This application relates to wireless communication systems, and more particularly to improving spectrum sharing by updating control information for dynamic time-division duplexing (TDD).

INTRODUCTION

A wireless communications system may operate over a shared spectrum, meaning that the wireless communications system includes one or more frequency bands that may be shared by multiple network operating entities. In some instances, multiple network operating entities may share their licensed spectrum with each other or with other third-party operators to better utilize the spectrum. One approach to sharing a medium or a spectrum is to employ a priority-based coordinated access scheme. In the priority-based coordinated access scheme, a shared spectrum is partitioned into multiple time periods. At any time period, one operator may be a primary user and have priority to access the spectrum while other operators may opportunistically access to the spectrum when the spectrum is available.

In addition to prioritizing spectrum access for different network operating entities, the scheme can prioritize spectrum access for different link directions within a network operating entity. While the scheme allows for dynamic TDD, where a link priority can be changed from a default link direction, a target receiver of a low priority link has no knowledge of whether a transmitter of the low priority link may proceed with a transmission as scheduled or yield access to the high priority link.

BRIEF SUMMARY OF SOME EXAMPLES

For example, in an aspect of the disclosure, a method of wireless communication includes communicating, by a first wireless communication device with a second wireless communication device, a first transmission grant for a transmission opportunity (TXOP) in a frequency band; performing, by the first wireless communication device, medium sensing for the TXOP; and transmitting, by the first wireless communication device to the second wireless communication device, an updated transmission grant for the TXOP based on at least the first transmission grant and the medium sensing.

In an additional aspect of the disclosure, a method of wireless communication includes communicating, by a first wireless communication device with a second wireless communication device, a first transmission grant for a transmission opportunity (TXOP) in a frequency band; and receiving, by the first wireless communication device from the second wireless communication device, an updated transmission grant for the TXOP based on a medium sensing for the TXOP.

In an additional aspect of the disclosure, an apparatus include a transceiver configured to communicate with a second wireless communication device, a first transmission grant for a transmission opportunity (TXOP) in a frequency band; and transmit, to the second wireless communication device, an updated transmission grant for the TXOP based on at least the first transmission grant and a medium sensing; and a processor configured to perform the medium sensing for the TXOP.

In an additional aspect of the disclosure, an apparatus includes a transceiver configured to communicate with a second wireless communication device, a first transmission grant for a transmission opportunity (TXOP) in a frequency band; and receive, from the second wireless communication device, an updated transmission grant for the TXOP based on a medium sensing for the TXOP.

DETAILED DESCRIPTION

The present disclosure describes mechanisms for updating control information in dynamic TDD. In a priority-based medium sharing scheme, one link direction may have priority over another link direction for accessing a transmission opportunity (TXOP) in a medium. For dynamic TDD, a DL-granting BS may transmit a DL schedule to a UE for a DL communication in the TXOP, while a UL-granting BS transmits a UL schedule to another UE for a UL communication in the TXOP. The target receiver of the high-priority link may transmit a reservation signal to indicate a reservation for the TXOP and to silence nodes of the low-priority link. The target transmitter of the low-priority link may monitor the medium for a reservation signal from the high-priority link. For a DL communication, the granting BS is a target transmitter and the scheduled UE is a target receiver. Conversely, for a UL communication, the scheduled UE is a target transmitter and the granting BS is a target receiver. In an embodiment, the low-priority target transmitter may update or modify the schedule, such as a modulation order, a code rate, a transmit power, a transmission rank, and/or a subband allocation, based on the monitoring. The low-priority target transmitter may transmit the updated schedule to the target receiver. Subsequently, the low-priority target transmitter may proceed to transmit data to the target receiver based on the updated schedule.

In one embodiment, the target transmitter may transmit the updated schedule via cross-carrier scheduling. In one embodiment, the target transmitter may transmit the updated schedule in a designated time period within the TXOP. In one embodiment, the target transmitter may transmit the updated schedule in a transmission period of the TXOP along with the data. For example, the target transmitter can configure the transmissions of the updated schedule and the data to have similar transmission property according to the medium sensing. When the low-priority link is DL, the updated schedule may be determined and transmitted by a corresponding DL-granting BS. In an embodiment when the low-priority link is UL, the updated schedule may be determined and transmitted by a corresponding scheduled UE.

Aspects of the present disclosure can provide several benefits. For example, the modifying of the initial schedule based on medium monitoring or sensing enable a target transmitter of a low-priority link to utilize at least some portions of resources in the medium instead of refraining from accessing the medium and abandoning the scheduled communication. Thus, the present disclosure can improve spectrum utilization efficiency while controlling interference between UL and DL. In addition, the additional signaling of the updated schedule enable the target receiver of a low-priority link to receive data according to the updated schedule instead of blind decoding, which may be complex and less accurate. Further, the disclosed embodiments allow a UE scheduled for a UL communication to modify a UL schedule and feedback the updated schedule to the granting BS. Thus, allowing control information update for both DL and UL directions in dynamic TDD.

FIG.1illustrates a wireless communication network100according to embodiments of the present disclosure. The network100includes BSs105, UEs115, and a core network130. In some embodiments, the network100operates over a shared spectrum. The shared spectrum may be unlicensed or partially licensed to one or more network operators. Access to the spectrum may be limited and may be controlled by a separate coordination entity. In some embodiments, the network100may be a LTE or LTE-A network. In yet other embodiments, the network100may be a millimeter wave (mmW) network, a new radio (NR) network, a 5G network, or any other successor network to LTE. The network100may be operated by more than one network operator. Wireless resources may be partitioned and arbitrated among the different network operators for coordinated communication between the network operators over the network100.

The BSs105may wirelessly communicate with the UEs115via one or more BS antennas. Each BS105may provide communication coverage for a respective geographic coverage area110. In 3GPP, the term “cell” can refer to this particular geographic coverage area of a BS and/or a BS subsystem serving the coverage area, depending on the context in which the term is used. In this regard, a BS105may provide communication coverage for a macro cell, a pico cell, a femto cell, and/or other types of cell. A macro cell generally covers a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by UEs with service subscriptions with the network provider. A pico cell may generally cover a relatively smaller geographic area and may allow unrestricted access by UEs with service subscriptions with the network provider. A femto cell may also generally cover a relatively small geographic area (e.g., a home) and, in addition to unrestricted access, may also provide restricted access by UEs having an association with the femto cell (e.g., UEs in a closed subscriber group (CSG), UEs for users in the home, and the like). A BS for a macro cell may be referred to as a macro BS. A BS for a pico cell may be referred to as a pico BS. A BS for a femto cell may be referred to as a femto BS or a home BS. In the example shown inFIG.1, the BSs105a,105band105care examples of macro BSs for the coverage areas110a,110band110c,respectively. The BSs105dis an example of a pico BS or a femto BS for the coverage area110d.As will be recognized, a BS105may support one or multiple (e.g., two, three, four, and the like) cells.

The BSs105may communicate with the core network130and with one another. The core network130may provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. At least some of the BSs105(e.g., which may be an example of an evolved NodeB (eNB), a next generation NodeB (gNB), or an access node controller (ANC)) may interface with the core network130through backhaul links132(e.g., S1, S2, etc.) and may perform radio configuration and scheduling for communication with the UEs115. In various examples, the BSs105may communicate, either directly or indirectly (e.g., through core network130), with each other over backhaul links134(e.g., X1, X2, etc.), which may be wired or wireless communication links.

Each BS105may also communicate with a number of UEs115through a number of other BSs105, where the BS105may be an example of a smart radio head. In alternative configurations, various functions of each BS105may be distributed across various BSs105(e.g., radio heads and access network controllers) or consolidated into a single BS105.

In some implementations, the network100utilizes orthogonal frequency division multiplexing (OFDM) on the downlink and single-carrier frequency division multiplexing (SC-FDM) on the UL. OFDM and SC-FDM partition the system bandwidth into multiple (K) orthogonal subcarriers, which are also commonly referred to as tones, bins, or the like. Each subcarrier may be modulated with data. In general, modulation symbols are sent in the frequency domain with OFDM and in the time domain with SC-FDM. The spacing between adjacent subcarriers may be fixed, and the total number of subcarriers (K) may be dependent on the system bandwidth. The system bandwidth may also be partitioned into subbands.

In an embodiment, a UE115attempting to access the network100may perform an initial cell search by detecting a primary synchronization signal (PSS) from a BS105. The PSS may enable synchronization of period timing and may indicate a physical layer identity value. The UE115may then receive a secondary synchronization signal (SSS). The SSS may enable radio frame synchronization, and may provide a cell identity value, which may be combined with the physical layer identity value to identify the cell. The SSS may also enable detection of a duplexing mode and a cyclic prefix length. Some systems, such as TDD systems, may transmit an SSS but not a PSS. Both the PSS and the SSS may be located in a central portion of a carrier, respectively. After receiving the PSS and SSS, the UE115may receive a master information block (MIB), which may be transmitted in the physical broadcast channel (PBCH). The MIB may contain system bandwidth information, a system frame number (SFN), and a Physical Hybrid-ARQ Indicator Channel (PHICH) configuration. After decoding the MIB, the UE115may receive one or more system information blocks (SIBs). For example, SIB1 may contain cell access parameters and scheduling information for other SIBs. Decoding SIB1 may enable the UE115to receive SIB2. SIB2 may contain radio resource configuration (RRC) configuration information related to random access channel (RACH) procedures, paging, physical uplink control channel (PUCCH), physical uplink shared channel (PUSCH), power control, SRS, and cell barring. After obtaining the MIB and/or the SIBs, the UE115can perform random access procedures to establish a connection with the BS105. After establishing the connection, the UE115and the BS105can enter a normal operation stage, where operational data may be exchanged.

In some embodiments, the UEs115and the BSs105may be operated by multiple network operators or network operating entities and may operate in a shared radio frequency spectrum, which may include licensed or unlicensed frequency bands. The shared spectrum may be time-partitioned for sharing among the multiple network operating entities to facilitate coordinated communication. For example, in the network100, the BS105aand the UE115amay be associated with one network operating entity, while the BS105band the UE115bmay be associated with another network operating entity. By time-partitioning the shared spectrum according to network operating entities, the communications between the BS105aand the UE115aand the communications between the BS105band the UE115bmay each occur during respective time periods and may avail themselves of an entirety of a designated shared spectrum.

To support coordinated access of the shared spectrum, a BS105or an entity of the core network130may act as a central arbitrator to manage access and coordinate the partitioning of resources among different network operating entities operating within the network100. In some embodiments, the central arbitrator may include a spectrum access system (SAS). In addition, the transmissions from the multiple network operating entities can be time synchronized to facilitate the coordination. Further, UL and DL access to the spectrum within a particular network operating entity can be prioritized and interference between UL and DL can be controlled and managed, as described in greater detailer herein.

FIG.2illustrates a coordinated priority-based spectrum sharing scheme200with interference management according to embodiments of the present disclosure. The x-axes represent time in some constant units. The y-axes represent frequency in some constant units. The scheme200may be employed by the BSs105and the UEs115to access a shared frequency band201. While the scheme200illustrates coordinated spectrum access for two different network operating entities (e.g., Operator A and Operator B), the scheme200can be applied to any suitable number of network operating entities, including three, four, or more operating entities.

In the scheme200, the frequency band201is time-partitioned into a plurality of transmit opportunities (TXOPs)202as shown in the frame structure205. The TXOPs202may have a fixed duration and may be defined in units of OFDM symbols, subframes, slots, and/or any suitable time format. In some embodiments, the TXOP202may have a duration of about 10 milliseconds (ms) to about 40 ms. Each TXOP202includes a plurality of channel sensing or clear channel assessment (CCA) periods204followed by a transmission period206. The CCA periods204are separated by a gap period219. The frame structure205of the TXOP202can be predetermined and known by all network operating entities sharing the frequency band201. The network operating entities may be time-synchronized when operating in the shared frequency band201.

Each CCA period204can be assigned to a particular network operating entity (e.g., Operator A or Operator B). The assigned network operating entity may transmit a reservation in the CCA period204to reserve the following transmission period206. Each CCA period204includes portions207,208, and209. The portions207and208are separated by a gap period217. The portions207are used for transmitting reservation request (RRQ) signals220. Each RRQ signal220may include a predetermined preamble sequence, a request-to-send (RTS) signal, and/or transmission triggers (e.g., scheduling information). The portions208are used for transmitting reservation response (RRS) signals222for operator-level sharing (e.g., across operators). The portions209are used for transmitting RRS signals224for link-level sharing (e.g., between UL and DL) within an operator. Each of the RRS signals222and224may include a predetermined preamble sequence or a clear-to-send (CTS) signal. The CCA periods204can be arranged in a decreasing order of priorities. Thus, a low-priority operator node can monitor the channel (e.g., the shared frequency band201) in the CCA periods204of higher priorities. Upon detection of a reservation from a high-priority operator node, the low-priority operator node may refrain from transmitting in the following transmission period206. The gap period219allows low-priority operator nodes to process the reservation of a higher priority operator. The gap period217allows for switching between UL and DL processing.

The transmission period206can include a DL control portion210, a data portion212, and a UL control portion214. The DL control portion210is used for transmitting DL controls230(e.g., UL or DL triggers) for the data portion212and/or the UL control portion214. The data portion212is used for transmitting UL or DL data232based on a corresponding DL control230. The UL control portion214is used for transmitting UL controls234(e.g., scheduling request (SR) and hybrid automatic repeat request (HARQ) information).

As an example, Operator A has priority over Operator B in the particular TXOP202. As such, the high-priority CCA period204ais assigned to Operator A and the low-priority CCA period204bis assigned to Operator B. The pattern-filled boxes shown with respect to the primary user and the secondary user inFIG.2represent signal transmissions. The dashed-outline boxes at the top ofFIG.2are included as references to the TXOP structure205without signal transmission.

For operator-level sharing, a BS of Operator A may transmit an RRQ signal220ain the portion207of the CCA period204ato reserve the following transmission period206. The RRQ signal220amay include a trigger for a UE. A target receiver corresponding to the trigger may transmit an RRS signal222ain the portion208of the CCA period204ato silence lower-priority operators (e.g., Operator B). When the trigger is a DL trigger, the UE is the target receiver. Conversely, when the trigger is a UL trigger, the BS is the target receiver. Subsequently, the Operator A BS may communicate a DL control230a,data232a,and a UL control234awith the triggered UE in the following transmission period206.

Operator B (e.g., the low-priority operator) may monitor the CCA period204afor an RRQ signal220aand/or an RRS signal222afrom Operator A (e.g., the high-priority operator). Upon detection of an RRQ signal220aand/or an RRS signal222afrom the high-priority Operator A, Operator B nodes may yield spectrum access to Operator A. However, when the shared frequency band201is not reserved by Operator A, Operator B may opportunistically access the transmission period206of the TXOP202using similar mechanisms as Operator A. For example, a BS of Operator B may transmit RRQ signal220bin the portion207of the assigned CCA period204bto trigger a UE for a communication in the transmission period206. A target receiver identified in the trigger may transmit an RRS signal222bin the portion208of the CCA period204bwhen there are lower priority operator nodes. When the trigger is a DL trigger, the target receiver is the UE. When the trigger is a UL trigger, the target receiver is the BS. Subsequently, the Operator B BS may communicate a DL control230b,data232b,and/or a UL control234bwith the triggered UE in the transmission period206.

For link-level sharing within Operator A or Operator B, Operator A or Operator B may use substantially similar reservation mechanisms as in the operator-level sharing. For example, DL may have priority over UL in the TXOP202. A target receiver of the high-priority link direction may transmit an RRS signal224in the portion209of a corresponding CCA period204to silence nodes of the low-priority link direction. In addition, dynamic TDD may be applied to the switch the prioritized link direction in the TXOP202, for example, from DL to UL. Further, the transmission period206may be further divided into sub-periods and dynamic TDD may be applied per sub-period. Mechanisms for performing dynamic TDD are described in greater detail herein.

FIGS.3and4illustrates further interference control in dynamic TDD based on the link-level sharing mechanisms in the scheme200described above with respect toFIG.2. InFIGS.3and4, the x-axes represent time in some constant units and the y-axes represent frequency in some constant units.

FIG.3illustrates a dynamic TDD scenario300according to embodiments of the present disclosure. In the scenario300, the transmission period206is time-partitioned into a plurality of sub-periods310shown as310SF_1to310SF_N. Each sub-period310can be a self-contained subframe. For example, a BS105may communicate with a UE115in each sub-period310. In some instances, each sub-period310may have a duration between about 500 microseconds (μs) to about 1 ms. Each sub-period310can be assigned with a default link direction for data communication. Dynamic TDD may be applied to dynamically change a link priority in each sub-period310using similar link-level sharing mechanisms as in the scheme200.

As an example, in the sub-period310SF_1, the high-priority link is UL and the low-priority link is DL. A UL-granting BS transmits an RRQ signal330(e.g., the RRQ signal220) during a portion307(e.g., the portion207) of the sub-period310SF_1. In some instances, the RRQ signal330may be similar to an LTE physical downlink control channel (PDCCH) signal. An LTE PDCCH signal may carry one or more transmission grants for one or more UEs. The transmission grants may be formatted according to LTE downlink control indicator (DCI) formats, which indicate resource blocks (e.g., frequency resources), MCS, and/or other transmission configuration parameters assigned to corresponding transmission grants. The RRQ signal330includes a UL transmission grant340for the UL-scheduled UE in a following portion306of the sub-period310SF_1. The UL transmission grant340may include scheduling information such as a modulation coding scheme (MCS), a subband allocation, a transmission rank, and/or pre-coding parameters. The UL-granting BS (e.g., the target receiver) transmits an RRS signal332(e.g., the RRS signals224) during a portion309(e.g., the portion209) of the sub-period310SF1to silence nodes of the low-priority link (e.g., DL). Subsequently, the UL-scheduled UE transmits UL data334(e.g., the data232) and a UL control336(e.g., the UL controls234) to the UL-granting BS during a portion306of the sub-period310SF1. The UL data334and the UL control336are transmitted according to the UL transmission grant340as shown by the dashed arrow342.

For dynamic TDD, a DL-granting BS transmits an RRQ signal320during the same portion307based on reuse one. The RRQ signal320may be similar to the RRQ signals220and330. The RRQ signal320indicates a DL transmission grant350for the DL-scheduled UE in the portion306. The DL transmission grant350may include scheduling information similar to the UL transmission grant340. The DL-scheduled UE (e.g., the target receiver) may transmit an RRS signal322(e.g., the RRS signals224) during the portion309to silence low-priority operator nodes. In some embodiments, the RRS signals322and332may be transmitted in different subbands of the frequency band201.

The DL-granting BS (e.g., the low-priority link) may monitor for an RRS signal332from the high-priority link (e.g., the UL) to determine whether the link direction can be switched. When no RRS signal332is detected, the DL-granting BS may proceed to transmit DL data324to the DL-scheduled UE and the DL-scheduled UE may transmit a UL control326according to the DL transmission grant350. However, upon detection of an RRS signal332from the high-priority link, the DL-granting BS may yield spectrum access to the high-priority link.

In some embodiments, the DL-granting BS may determine that the receive signal strength of the RRS signal332is sufficiently low, indicating that the high-priority receiver may be substantially far away from the DL-granting BS. Thus, the DL-granting BS may determine that a transmission from the DL-granting BS may not have a significant interference impact on the high-priority UL communication and proceed with the scheduled DL transmission.

Alternatively, the DL-granting BS may determine the receive signal strength of the RRS signal332may be relatively strong, indicating that the high-priority receiver may be relatively close to the DL-granting BS. To improve spectrum utilization efficiency, the DL-granting BS may modify the DL schedule instead of completely yielding access to the high-priority UL communication. For example, the DL-granting BS may reduce the transmit power and/or modify other transmission parameters based on the detection to minimize interference impact on the UL communication (e.g., the UL data334and the UL control336) and continue with the transmission of the DL data324. Thus, the transmission of DL data324may not match the initial DL transmission grant350as shown by the dashed arrow352with the cross. However, the DL-scheduled UE has no knowledge of the yielding and/or the DL schedule change, and thus may rely on blind detection to detect and decode the DL data324.

FIG.4illustrates a dynamic TDD scenario400according to embodiments of the present disclosure. The scenario400is substantially similar to the scenario300. However, in the scenario400, the high-priority link in the sub-period310SF_1is DL instead of UL as in the scenario300. In the scenario400, a DL-granting BS and a UL-granting BS may schedule a DL communication and a UL communication, respectively, using similar mechanisms as in the scheme200and the scenario300. The communication (e.g., the DL data324and the UL control326) over the high-priority link (e.g., DL) may proceed according to the initial DL transmission grant350as shown by the dashed arrow404. Similar to the scenario300, the communication (e.g., the UL data334and the UL control336) over the low-priority link (e.g., UL) may proceed without yielding, but the scheduling or transmission parameters may be modified such that the interference impact on the high-priority DL communication may be minimized Thus, the transmission of UL data334may not match the initial UL transmission grant340as shown by the dashed arrow402with the cross. The UL-granting BS may have no knowledge of the scheduling adjustment, and thus may rely on blind detection to detect and decode the UL data334.

While the low-priority receivers in the scenarios300or400may apply blind detection for the data reception or detection, blind detection may be complex and may not be accurate in some instances. To facilitate the schedule adjustment, the target transmitter may signal the updated schedule prior to the transmission, as described in greater detail herein.

FIG.5is a block diagram of an exemplary UE500according to embodiments of the present disclosure. The UE500may be a UE115as discussed above. As shown, the UE500may include a processor502, a memory504, a medium sharing module508, a transceiver510including a modem subsystem512and a radio frequency (RF) unit514, and one or more antennas516. These elements may be in direct or indirect communication with each other, for example via one or more buses.

The processor502may include a central processing unit (CPU), a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a controller, a field programmable gate array (FPGA) device, another hardware device, a firmware device, or any combination thereof configured to perform the operations described herein. The processor502may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

The memory504may include a cache memory (e.g., a cache memory of the processor502), random access memory (RAM), magnetoresistive RAM (MRAM), read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read only memory (EPROM), electrically erasable programmable read only memory (EEPROM), flash memory, solid state memory device, hard disk drives, other forms of volatile and non-volatile memory, or a combination of different types of memory. In an embodiment, the memory504includes a non-transitory computer-readable medium. The memory504may store instructions506. The instructions506may include instructions that, when executed by the processor502, cause the processor502to perform the operations described herein with reference to the UEs215in connection with embodiments of the present disclosure. Instructions506may also be referred to as code. The terms “instructions” and “code” should be interpreted broadly to include any type of computer-readable statement(s). For example, the terms “instructions” and “code” may refer to one or more programs, routines, sub-routines, functions, procedures, etc. “Instructions” and “code” may include a single computer-readable statement or many computer-readable statements.

The medium sharing module508may be implemented via hardware, software, or combinations thereof. For example, the medium sharing module508may be implemented as a processor, circuit, and/or instructions506stored in the memory504and executed by the processor502. The medium sharing module508may be used for various aspects of the present disclosure. For example, the medium sharing module508is configured to identify TXOPs in a shared medium, perform medium sensing, receive scheduling information for UL and/or DL communications, perform dynamic TDD, determine updates for UL scheduling information during link-priority switching, and/or monitor for updated DL scheduling information during link-priority switching, as described in greater detail herein.

As shown, the transceiver510may include the modem subsystem512and the RF unit514. The transceiver510can be configured to communicate bi-directionally with other devices, such as the BSs105and305. The modem subsystem512may be configured to modulate and/or encode the data from the memory504and/or the medium sharing module508according to a modulation and coding scheme (MCS), e.g., a low-density parity check (LDPC) coding scheme, a turbo coding scheme, a convolutional coding scheme, a digital beamforming scheme, etc. The RF unit514may be configured to process (e.g., perform analog to digital conversion or digital to analog conversion, etc.) modulated/encoded data from the modem subsystem512(on outbound transmissions) or of transmissions originating from another source such as a UE115or a BS105. The RF unit514may be further configured to perform analog beamforming in conjunction with the digital beamforming. Although shown as integrated together in transceiver510, the modem subsystem512and the RF unit514may be separate devices that are coupled together at the UE215to enable the UE215to communicate with other devices.

The RF unit514may provide the modulated and/or processed data, e.g. data packets (or, more generally, data messages that may contain one or more data packets and other information), to the antennas516for transmission to one or more other devices. This may include, for example, transmission of RRS signals, updated control information, CSI-RSs, and/or SRSs according to embodiments of the present disclosure. The antennas516may further receive data messages transmitted from other devices. The antennas516may provide the received data messages for processing and/or demodulation at the transceiver510. The antennas516may include multiple antennas of similar or different designs in order to sustain multiple transmission links. The RF unit514may configure the antennas516.

FIG.6is a block diagram of an exemplary BS600according to embodiments of the present disclosure. The BS600may be a BS105as discussed above. A shown, the BS600may include a processor602, a memory604, a medium sharing module608, a transceiver610including a modem subsystem612and a RF unit614, and one or more antennas616. These elements may be in direct or indirect communication with each other, for example via one or more buses.

The memory604may include a cache memory (e.g., a cache memory of the processor602), RAM, MRAM, ROM, PROM, EPROM, EEPROM, flash memory, a solid state memory device, one or more hard disk drives, memristor-based arrays, other forms of volatile and non-volatile memory, or a combination of different types of memory. In some embodiments, the memory604may include a non-transitory computer-readable medium. The memory604may store instructions606. The instructions606may include instructions that, when executed by the processor602, cause the processor602to perform operations described herein. Instructions606may also be referred to as code, which may be interpreted broadly to include any type of computer-readable statement(s) as discussed above with respect toFIG.6.

The medium sharing module608may be implemented via hardware, software, or combinations thereof. For example, the medium sharing module608may be implemented as a processor, circuit, and/or instructions606stored in the memory604and executed by the processor602. The medium sharing module608may be used for various aspects of the present disclosure. For example, the medium sharing module608is configured to identify TXOPs in a shared spectrum, perform medium sensing, determine scheduling information for UL and/or DL communications, perform dynamic TDD, determine updates for DL scheduling information during link-priority switching, and/or monitor for updated UL scheduling information for link-priority switching, as described in greater detail herein.

As shown, the transceiver610may include the modem subsystem612and the RF unit614. The transceiver610can be configured to communicate bi-directionally with other devices, such as the UEs115and215and/or another core network element. The modem subsystem612may be configured to modulate and/or encode data according to a MCS, e.g., a LDPC coding scheme, a turbo coding scheme, a convolutional coding scheme, a digital beamforming scheme, etc. The RF unit614may be configured to process (e.g., perform analog to digital conversion or digital to analog conversion, etc.) modulated/encoded data from the modem subsystem612(on outbound transmissions) or of transmissions originating from another source such as a UE115. The RF unit614may be further configured to perform analog beamforming in conjunction with the digital beamforming. Although shown as integrated together in transceiver610, the modem subsystem612and the RF unit614may be separate devices that are coupled together at the BS105to enable the BS105to communicate with other devices.

The RF unit614may provide the modulated and/or processed data, e.g. data packets (or, more generally, data messages that may contain one or more data packets and other information), to the antennas616for transmission to one or more other devices. This may include, for example, transmission of information to complete attachment to a network and communication with a camped UE115according to embodiments of the present disclosure. The antennas616may further receive data messages transmitted from other devices and provide the received data messages for processing and/or demodulation at the transceiver610. The antennas616may include multiple antennas of similar or different designs in order to sustain multiple transmission links.

FIGS.7-9illustrate various mechanisms that may be employed by the low-priority DL-granting BS in the scenario300to signal updated DL scheduling information based on medium sensing, for example, upon detecting a reservation from the high-priority link (e.g., UL). InFIGS.7-9, the x-axes represent time in some constant units and the y-axes represent frequency in some constant units.

FIG.7illustrates a DL control information update signaling scheme700according to embodiments of the present disclosure. In the scheme700, a DL-granting BS of a low-priority link may transmit an RRQ signal320to schedule a UE for a DL communication in the sub-period310. The RRQ signal320may include a DL transmission grant350for the scheduled UE. The DL transmission grant350may include scheduling information such as MCS, a transmit power, a transmission rank, pre-coding parameters, a subband allocation in the frequency band201, and/or any other transmission-related parameters. The DL-granting BS (e.g., the target transmitter) may perform medium sensing in the frequency band201after transmitting the RRQ signal320. For example, the DL-granting BS may perform medium sensing to determine whether the sub-period310is reserved by the high-priority link for a UL communication (e.g., the UL data334and the UL control336).

After performing the medium sensing, the DL-granting BS generates an updated DL transmission grant710based on the initial DL transmission grant350and the medium sensing. For example, the DL-granting BS may detect an RRS signal332from the high-priority link. The DL-granting BS may determine an expected interference that the DL-granting BS may generate towards the high-priority UL communication, for example, based on the signal strength of the RRS signal332. The DL-granting BS may modify one or more of the transmission parameters in the initial DL transmission grant350to minimize the potential interference from a DL transmission of the DL-granting BS to the high-priority UL communication.

In an embodiment, the DL-granting BS may detect an RRS signal332with relatively strong signal strength, indicating that a high-priority receiver may be located relatively close to the DL-granting BS. As such, the DL-granting BS may determine to reduce the transmit power for the DL communication so that the interference impact to the UL communication may be reduced. For example, the DL-granting BS may select a modulation order and/or a code rate that are lower than the modulation order and/or code rate in the initial DL transmission grant350so that the DL communication may be received and decoded correctly by the DL-scheduled UE at the reduced transmit power.

In an embodiment, the DL-granting BS may detect an RRS signal332from the high-priority link in a particular subband of the frequency band201that is initially scheduled for the DL communication. To reduce the interference impact on the UL communication, the DL-granting BS may select a different subband for the DL communication.

In an embodiment, the DL-granting BS may detect an RRS signal332from the high-priority link in a particular spatial layer that is initially scheduled for the DL communication. To reduce the interference impact on the UL communication, the DL-granting BS may modify the transmission rank and/or the pre-coding parameters of the DL communication.

To signal the scheduling update, the DL-granting BS applies cross-carrier scheduling to transmit the updated DL transmission grant710in a frequency band702different from the frequency band201. For example, the frequency band702may be a licensed carrier of an operating entity of the DL-granting BS. Alternatively, the frequency band702may be a shared or unlicensed carrier that the DL-granting BS is allowed to access. The DL-granting BS may transmit the DL data324according to the updated DL transmission grant710as shown by the dashed arrow704. In some instances, the frequency band702may be a primary component carrier and the frequency band201may be a secondary component carrier. For example, the DL-scheduled UE may have previously established a connection with the DL-scheduled UE in the frequency band702. Thus, the DL-scheduled UE may receive the updated DL transmission grant710in the frequency band702and receive the DL data324in the frequency band201according to the updated DL transmission grant710.

FIG.8illustrates a DL control information update signaling scheme800according to embodiments of the present disclosure. The scheme800is similar to the scheme700. However, the scheme800includes a time period802designated for transmission of updated scheduling information. The time period802can be between the portion309and the portion306. As shown, the DL-granting BS transmits the updated DL transmission grant710in the time period802. In some embodiments, the updated DL transmission grant710may be transmitted using the same transmission configuration (e.g., modulation order, code rate, transmission power, aggregation level, and/or subband) as the initial DL transmission grant350. Subsequently, the DL-granting BS transmits the DL data324according to the updated DL transmission grant710during the portion306as shown by the arrow804. The addition of the designated time period802may delay the start of the portion306, reducing resources that may be utilized by the high-priority link. While scheme800may be less efficient in spectrum utilization compared to the scheme700, the scheme800may have less scheduling complexity.

FIG.9illustrates a DL control information update signaling scheme900according to embodiments of the present disclosure. The scheme900is similar to the schemes700and800. However, the scheme900allows for updated scheduling information transmission along with data transmission. As shown, the DL-granting BS transmits the updated DL transmission grant710and the DL data324during the portion306, where no additional time period is dedicated for the transmission of the updated DL transmission grant710as in the scheme800. The updated DL transmission grant710and the DL data324are transmitted according to the medium sensing. Thus, the DL-scheduled UE may decode the updated DL transmission grant710followed by decoding the DL data324according to the updated scheduling information decoded from the updated DL transmission grant710as shown by the arrow904.

As shown, the updated transmission grant710can be transmitted at the same time as the high-priority UL communication. Thus, the transmission of the updated DL transmission grant710may be impacted by interference from the UL communication. As such, in some instances the updated DL transmission grant710can still be decoded when the DL-granting BS uses a reduced transmit power or bandwidth due to the reservation of the high-priority link. In an embodiment, the frequency band201may be divided into a number of frequency subbands. The DL-granting BS may transmit the updated DL transmission grant710within a subband so that the updated scheduling information may be self-contained within the subband. Thus, the scheduling information can be self-decodable within the subband.

In some embodiments, the scheduling information in the initial DL transmission grant350may include a subband configuration. In such embodiments, the updated DL transmission grant710may be transmitted in one or more subband(s) according to the subband configuration and may indicate updated scheduling information associated with other subband(s).

In some embodiments, the updated DL transmission grant710may be transmitted over multiple subbands of the frequency band201. For example, subband aggregation similar to the control channel element (CCE) aggregation in LTE PDCCH may be applied for the signaling of the updated DL transmission grant710to enable the DL-granting BS to further reduce transmit power. LTE supports aggregation levels 1, 2, 4, and 8, where 1, 2, 4, and 8 CCEs, respectively, may be used to carry a transmission grant. Thus, subband aggregation can be applied to transmit the updated DL transmission grant710over 1, 2, 4, or 8 subbands or any suitable number of subbands. However, the aggregation may increase the decoding complexity at the DL-scheduled UE. While the scheme900may be more efficient in spectrum utilization compared to the scheme800and may have less scheduling complexity compared to the scheme700, the scheme900may have a higher implementation complexity at the DL-scheduled UE.

FIGS.10-12illustrate various mechanisms that may be employed by the low-priority UL-granting BS in the scenario400to signal updated UL scheduling information based on medium sensing, for example, upon detecting a reservation from the high-priority link (e.g., DL). InFIGS.10-12, the x-axes represent time in some constant units and the y-axes represent frequency in some constant units.

FIG.10illustrates a UL control information update signaling scheme1000according to embodiments of the present disclosure. The scheme1000is substantially similar to the scheme700, but illustrates signaling of UL scheduling update instead of DL scheduling update. In the scheme1000, a UL-granting BS of a low-priority link may transmit an RRQ signal330to schedule a UE for a UL communication in the sub-period310. The RRQ signal330may include a UL transmission grant340for the scheduled UE. The UL transmission grant340may include scheduling information such as a MCS, a transmit power, a transmission rank, pre-coding parameters, a subband allocation in the frequency band201, and/or any other transmission-related parameters . The scheduled UE in the uplink may perform medium sensing to monitor for a reservation signal (e.g., the RRS signal322) from the high-priority link (e.g., DL).

After performing the medium sensing, the UE scheduled by the UL-granting BS generates an updated UL transmission grant1010based on the initial UL grant340received from the UL-granting BS and the medium sensing. For example, the scheduled UE may determine an expected interference that the scheduled UE may generate towards the high-priority DL communication based on signal strengths of reservation signals detected from the medium sensing. The scheduled UE may modify one or more of the transmission parameters in the initial UL transmission grant340to minimize the potential interference from a UL transmission of the scheduled UE to the high-priority DL communication.

In an embodiment, the scheduled UE may detect an RRS signal322with relatively strong signal strength, indicating that a high-priority receiver may be located relatively close to the scheduled UE. As such, the scheduled UE may determine to reduce the transmit power for the UL communication. For example, the scheduled UE may select a modulation order and/or a code rate that are lower than the modulation order and/or code rate assigned by the UL-granting BS.

In an embodiment, the scheduled UE may detect an RRS signal332in a particular subband of the frequency band201that is included in the UL schedule of the UL transmission grant340. To reduce the interference impact on the DL communication, the scheduled UE may select a different subband for the UL communication.

In an embodiment, the scheduled UE may detect an RRS signal332in a particular spatial layer that is included in the UL schedule of the UL transmission grant340. To reduce the interference impact on the DL communication, the scheduled UE may modify the transmission rank and/or the pre-coding parameters of the UL communication.

To signal the scheduling update, the scheduled UE applies cross-carrier scheduling to transmit the updated UL transmission grant1010in a frequency band1002different from the frequency band201. The scheduled UE may transmit the UL data334according to the updated UL transmission grant1010as shown by the dashed arrow1004. In some instances, the frequency band1002may be a primary component carrier and the frequency band201may be a secondary component carrier. For example, the scheduled UE may have previously established a connection with the UL-granting BS in the frequency band1002. Thus, the UL-granting BS may receive the updated UL transmission grant1010in the frequency band1002and receive the DL data324in the frequency band201according to the updated UL transmission grant1010.

FIG.11illustrates a UL control information update signaling scheme1100according to embodiments of the present disclosure. The scheme1100is substantially similar to the scheme800, but illustrates signaling of UL scheduling update instead of DL scheduling update. The scheme1100includes a time period1102(e.g., the time period802) designated for transmission of updated scheduling information. As shown, the scheduled UE transmits the updated UL transmission grant1010in the designated time period1102. In some embodiments, the updated UL transmission grant1010may be transmitted using the same transmission configuration (e.g., modulation order, code rate, transmission power, aggregation level, and/or subband) as the initial UL transmission grant340. Subsequently, the scheduled UE transmits the UL data334according to the updated UL transmission grant1010during the portion306as shown by the arrow1104. Similar to the scheme800, the addition of the designated time period1102may delay the start of the portion306.

FIG.12illustrates a UL control information update signaling scheme1200according to embodiments of the present disclosure. The scheme1200is substantially similar to the schemes900, but illustrates signaling of UL scheduling update instead of DL scheduling update. The scheme1200allows for updated scheduling information transmission along with data transmission. As shown, the scheduled UE transmits the updated UL transmission grant1010and the UL data334during the portion306. Thus, the UL-granting BS may decode the updated UL transmission grant1010followed by decoding the UL data334according to the updated scheduling information decoded from the UL transmission grant1010as shown by the arrow1204. In addition, the scheduled UE may employ similar mechanisms as in the scheme900described with respect toFIG.9to transmit the updated UL transmission grant1010in a subband of the frequency band201, repeating transmission of the updated UL transmission grant1010in multiple subbands, and/or indicating scheduling information associated with another subband of the frequency band201.

FIG.13is a flow diagram of a control information update method1300according to embodiments of the present disclosure. Steps of the method1300can be executed by a computing device (e.g., a processor, processing circuit, and/or other suitable component) of a wireless communication device, such as the BSs105and600and the UEs115and500. The method1300may employ similar mechanisms as in the schemes200,700,800,900,1000,1100, and1200described with respect toFIGS.2,7,8,9,10,11, and12respectively. As illustrated, the method1300includes a number of enumerated steps, but embodiments of the method1300may include additional steps before, after, and in between the enumerated steps. In some embodiments, one or more of the enumerated steps may be omitted or performed in a different order.

At step1310, the method1300includes communicating a first transmission grant (e.g., the transmission grants340and350) for a TXOP (e.g., the TXOPs202or the sub-periods310) in a frequency band (e.g., the frequency band201). The first transmission grant is for the wireless communication device to transmit in the TXOP. For example, the wireless communication device may represent a BS when the first transmission grant is a DL transmission grant and the BS may transmit the first transmission grant. Alternatively, the wireless communication device may represent a UE when the first transmission grant is a UL transmission grant and the UE may receive the first transmission grant.

At step1320, the method1300includes performing medium sensing in the frequency band for the TXOP. The medium sensing may include monitoring for a reservation signal (e.g., the RRS signals322and332) for the TXOP. The reservation signal may be for a communication in a first link direction and the first transmission grant may be for a communication in a second link direction. For example, the first link direction may be UL and the second link direction may be DL. Alternatively, the first link direction may be DL and the second link direction may be UL.

At step1330, the method1300includes transmitting an updated transmission grant (e.g., the updated transmission grants710and1010) based on at least the first transmission grant and the medium sensing. The updated transmission grant may include an updated transmission configuration such as a subband allocation in the frequency band, a (MCS, a transmission power, or a transmission rank that is different from the first transmission grant. The wireless communication device may determine the updated transmission configuration for interference management, for example, to reduce interference on the communication in the first link direction. The updated transmission grant may be transmitted in another frequency band (e.g., in the frequency bands702and1002), in a designated time period (e.g., the time periods802and1102) within the TXOP, or in a transmission period (e.g., the portion306) within the TXOP along with data.

At step1340, the method1300includes transmitting data (e.g., the DL data324and the UL data334) in the TXOP based on the updated transmission grant.

FIG.14is a flow diagram of a control information update method1400according to embodiments of the present disclosure. Steps of the method1400can be executed by a computing device (e.g., a processor, processing circuit, and/or other suitable component) of a wireless communication device, such as the BSs105and600and the UEs115and500. The method1300may employ similar mechanisms as in the schemes200,700,800,900,1000,1100, and1200described with respect toFIGS.2,7,8,9,10,11, and12respectively. As illustrated, the method1400includes a number of enumerated steps, but embodiments of the method1400may include additional steps before, after, and in between the enumerated steps. In some embodiments, one or more of the enumerated steps may be omitted or performed in a different order.

At step1410, the method1400includes communicating a first transmission grant (e.g., the transmission grants340and350) for a TXOP (e.g., the TXOPs202or the sub-periods310) in a frequency band (e.g., the frequency band201). The first transmission grant is for the wireless communication device to receive in the TXOP. For example, the wireless communication device may represent a UE when the first transmission grant is a DL transmission grant. Alternatively, the wireless communication device may represent a BS when the first transmission grant is a UL transmission grant.

At step1420, the method1400includes receiving an updated transmission grant (e.g., the updated transmission grants710and1010) based on medium sensing for the TXOP. The updated transmission grant may include an updated transmission configuration such as a subband allocation in the frequency band, a modulation coding scheme (MCS), a transmission power, or a transmission rank that is different from the first transmission grant. The updated transmission grant may be received in another frequency band (e.g., in the frequency bands702and1002), in a designated time period (e.g., the time period802and1102) within the TXOP, or in a transmission period (e.g., the portion306) along with data.

At step1430, the method1400includes receiving data (e.g., the DL data324and the UL data334) during the TXOP based on the updated transmission grant.

Further embodiments of the disclosure include a method of wireless communication, comprising communicating, by a first wireless communication device with a second wireless communication device, a first transmission grant for a transmission opportunity (TXOP) in a frequency band; performing, by the first wireless communication device, medium sensing for the TXOP; and transmitting, by the first wireless communication device to the second wireless communication device, an updated transmission grant for the TXOP based on at least the first transmission grant and the medium sensing.

The method further includes wherein the performing the medium sensing includes detecting a reservation signal for the TXOP. The method further includes wherein the performing the medium sensing includes detecting a reservation signal for communicating in a first link direction during the TXOP, wherein the first transmission grant and the updated transmission grant are for communicating in a second link direction, and wherein the first link direction and the second link direction are different. The method further includes transmitting, by the first wireless communication device to the second wireless communication device in the frequency band, data during the TXOP based on the updated transmission grant. The method further includes wherein the communicating includes transmitting, by the first wireless communication device to the second wireless communication device, the first transmission grant. The method further includes wherein the communicating includes receiving, by the first wireless communication device from the second wireless communication device, the first transmission grant. The method further includes wherein the first wireless communication device is a user equipment. The method further includes generating, by the first wireless communication device, the updated transmission grant by modifying scheduling information in the first transmission grant based on at least the medium sensing. The method further includes wherein the updated transmission grant includes at least one of a subband allocation in the frequency band, a modulation coding scheme (MCS), a transmission power, or a transmission rank that is different from the first transmission grant. The method further includes wherein the transmitting the updated transmission grant includes transmitting the updated transmission grant in another frequency band. The method further includes wherein the TXOP includes a designated time period for an updated transmission grant transmission, and wherein the transmitting the updated transmission grant includes transmitting the updated transmission grant in the frequency band during the designated time period. The method further includes wherein the medium sensing is for a transmission period of the TXOP, and wherein the transmitting the updated transmission grant includes transmitting the updated transmission grant in the frequency band during the transmission period. The method further includes wherein the transmitting the updated transmission grant includes transmitting the updated transmission grant in a first subband of the frequency band, wherein the updated transmission grant indicates updated scheduling information associated with a second subband of the frequency band, and wherein the first subband and the second subband are different.

Further embodiments of the disclosure include a method of wireless communication, comprising communicating, by a first wireless communication device with a second wireless communication device, a first transmission grant for a transmission opportunity (TXOP) in a frequency band; and receiving, by the first wireless communication device from the second wireless communication device, an updated transmission grant for the TXOP based on a medium sensing for the TXOP.

The method further includes receiving, by the first wireless communication device from the second wireless communication device, data in the frequency band during the TXOP based on the updated transmission grant. The method further includes wherein the communicating includes transmitting, by the first wireless communication device to the second wireless communication device, the first transmission grant. The method further includes wherein the communicating includes receiving, by the first wireless communication device from the second wireless communication device, the first transmission grant. The method further includes wherein the updated transmission grant includes at least one of a subband allocation in the frequency band, a modulation coding scheme (MCS), a transmission power, or a transmission rank that is different from the first transmission grant. The method further includes wherein the receiving the updated transmission grant includes receiving the updated transmission grant in another frequency band. The method further includes wherein the TXOP includes a designated time period for an updated transmission grant transmission, and wherein the receiving the updated transmission grant includes receiving the updated transmission grant in the frequency band during the designated time period. The method further includes wherein the medium sensing is for a transmission period of the TXOP, and wherein the receiving the updated transmission grant includes receiving the updated transmission grant in the frequency band during the transmission period. The method further includes wherein the receiving the updated transmission grant includes receiving the updated transmission grant in a first subband of the frequency band, wherein the updated transmission grant indicates updated scheduling information associated with a second subband of the frequency band, and wherein the first subband and the second subband are different.

Further embodiments of the disclosure include an apparatus comprising a transceiver configured to communicate with a second wireless communication device, a first transmission grant for a transmission opportunity (TXOP) in a frequency band; and transmit, to the second wireless communication device, an updated transmission grant for the TXOP based on at least the first transmission grant and a medium sensing; and a processor configured to perform the medium sensing for the TXOP.

The apparatus further includes wherein the processor is further configured to perform the medium sensing by detecting a reservation signal for the TXOP. The apparatus further includes wherein the processor is further configured to perform the medium sensing by detecting a reservation signal for communicating in a first link direction during the TXOP, wherein the first transmission grant and the updated transmission grant are for communicating in a second link direction, and wherein the first link direction and the second link direction are different. The apparatus further includes wherein the transceiver is further configured to transmit, to the second wireless communication device in the frequency band, data during the TXOP based on the updated transmission grant. The apparatus further includes wherein the transceiver is further configured to communicate the first transmission grant by transmitting, to the second wireless communication device, the first transmission grant. The apparatus further includes wherein the transceiver is further configured to communicate the first transmission grant by receiving, from the second wireless communication device, the first transmission grant. The apparatus further includes wherein the apparatus is a user equipment. The apparatus further includes wherein the processor is further configured to generate the updated transmission grant by modifying scheduling information in the first transmission grant based on at least the medium sensing. The apparatus further includes wherein the updated transmission grant includes at least one of a subband allocation in the frequency band, a modulation coding scheme (MCS), a transmission power, or a transmission rank that is different from the first transmission grant. The apparatus further includes wherein the transceiver is further configured to transmit the updated transmission grant in another frequency band. The apparatus further includes wherein the TXOP includes a designated time period for an updated transmission grant transmission, and wherein the transceiver is further configured to transmit the updated transmission grant in the frequency band during the designated time period. The apparatus further includes wherein the medium sensing is for a transmission period of the TXOP, and wherein the transceiver is further configured to transmit the updated transmission grant in the frequency band during the transmission period. The apparatus further includes wherein the transceiver is further configured to transmit the updated transmission grant in a first subband of the frequency band, wherein the updated transmission grant indicates updated scheduling information associated with a second subband of the frequency band, and wherein the first subband and the second subband are different.

Further embodiments of the disclosure include an apparatus comprising a transceiver configured to communicate with a second wireless communication device, a first transmission grant for a transmission opportunity (TXOP) in a frequency band; and receive, from the second wireless communication device, an updated transmission grant for the TXOP based on a medium sensing for the TXOP.

The apparatus further includes wherein the transceiver is further configured to receive, from the second wireless communication device, data in the frequency band during the TXOP based on the updated transmission grant. The apparatus further includes wherein the transceiver is further configured to communicate the first transmission grant by transmitting, to the second wireless communication device, the first transmission grant. The apparatus further includes wherein the transceiver is further configured to communicate the first transmission grant by receiving, from the second wireless communication device, the first transmission grant. The apparatus further includes wherein the updated transmission grant includes at least one of a subband allocation in the frequency band, a modulation coding scheme (MCS), a transmission power, or a transmission rank that is different from the first transmission grant. The apparatus further includes wherein the transceiver is further configured to receive the updated transmission grant in another frequency band. The apparatus further includes wherein the TXOP includes a designated time period for an updated transmission grant transmission, and wherein the transceiver is further configured to receive the updated transmission grant in the frequency band during the designated time period. The apparatus further includes wherein the medium sensing is for a transmission period of the TXOP, and wherein the transceiver is further configured to receive the updated transmission grant in the frequency band during the transmission period. The apparatus further includes wherein the transceiver is further configured to receive the updated transmission grant in a first subband of the frequency band, wherein the updated transmission grant indicates updated scheduling information associated with a second subband of the frequency band, and wherein the first subband and the second subband are different.

Further embodiments of the disclosure include a computer-readable medium having program code recorded thereon, the program code comprising code for causing a first wireless communication device to communicate with a second wireless communication device, a first transmission grant for a transmission opportunity (TXOP) in a frequency band; code for causing the first wireless communication device to perform medium sensing for the TXOP; and code for causing the first wireless communication device to transmit, to the second wireless communication device, an updated transmission grant for the TXOP based on at least the first transmission grant and the medium sensing.

The computer-readable medium further includes wherein the code for causing the first wireless communication device to perform the medium sensing is further configured to detect a reservation signal for the TXOP. The computer-readable medium further includes wherein the code for causing the first wireless communication device to performing the medium sensing is further configured to detect a reservation signal for communicating in a first link direction during the TXOP, wherein the first transmission grant and the updated transmission grant are for communicating in a second link direction, and wherein the first link direction and the second link direction are different. The computer-readable medium further includes code for causing the first wireless communication device to transmit, to the second wireless communication device in the frequency band, data during the TXOP based on the updated transmission grant. The computer-readable medium further includes wherein the code for causing the first wireless communication device to communicating first transmission grant is further configured to transmit, to the second wireless communication device, the first transmission grant. The computer-readable medium further includes wherein the code for causing the first wireless communication device to communicate the first transmission grant is further configured to receive, from the second wireless communication device, the first transmission grant. The computer-readable medium further includes wherein the first wireless communication device is a user equipment. The computer-readable medium further includes code for causing the first wireless communication device to generate the updated transmission grant by modifying scheduling information in the first transmission grant based on at least the medium sensing. The computer-readable medium further includes wherein the updated transmission grant includes at least one of a subband allocation in the frequency band, a modulation coding scheme (MCS), a transmission power, or a transmission rank that is different from the first transmission grant. The computer-readable medium further includes wherein the code for causing the first wireless communication device to transmit the updated transmission grant is further configured to transmit the updated transmission grant in another frequency band. The computer-readable medium further includes wherein the TXOP includes a designated time period for an updated transmission grant transmission, and wherein the code for causing the first wireless communication device to transmitting the updated transmission grant is further configured to transmit the updated transmission grant in the frequency band during the designated time period. The computer-readable medium further includes wherein the medium sensing is for a transmission period of the TXOP, and wherein the code for causing the first wireless communication device to transmit the updated transmission grant is further configured to transmit the updated transmission grant in the frequency band during the transmission period. The computer-readable medium further includes wherein the code for causing the first wireless communication device to transmit the updated transmission grant is further configured to transmit the updated transmission grant in a first subband of the frequency band, wherein the updated transmission grant indicates updated scheduling information associated with a second subband of the frequency band, and wherein the first subband and the second subband are different.

Further embodiments of the disclosure include a computer-readable medium having program code recorded thereon, the program code comprising code for causing a first wireless communication device to communicate with a second wireless communication device, a first transmission grant for a transmission opportunity (TXOP) in a frequency band; and code for causing the first wireless communication device to receive, from the second wireless communication device, an updated transmission grant for the TXOP based on a medium sensing for the TXOP.

The computer-readable medium further includes code for causing the first wireless communication device to receive, from the second wireless communication device, data in the frequency band during the TXOP based on the updated transmission grant. The computer-readable medium further includes wherein the code for causing the first wireless communication device to communicate the first transmission grant is further configured to transmit, to the second wireless communication device, the first transmission grant. The computer-readable medium further includes wherein the code for causing the first wireless communication device to communicate the first transmission grant is further configured to receive, from the second wireless communication device, the first transmission grant. The computer-readable medium further includes wherein the updated transmission grant includes at least one of a subband allocation in the frequency band, a modulation coding scheme (MCS), a transmission power, or a transmission rank that is different from the first transmission grant. The computer-readable medium further includes wherein the code for causing the first wireless communication device to receive the updated transmission grant is further configured to receive the updated transmission grant in another frequency band. The computer-readable medium further includes wherein the TXOP includes a designated time period for an updated transmission grant transmission, and wherein the code for causing the first wireless communication device to receive the updated transmission grant is further configured to receive the updated transmission grant in the frequency band during the designated time period. The computer-readable medium further includes wherein the medium sensing is for a transmission period of the TXOP, and wherein the code for causing the first wireless communication device to receive the updated transmission grant is further configured to receive the updated transmission grant in the frequency band during the transmission period. The computer-readable medium further includes wherein the code for causing the first wireless communication device to receive the updated transmission grant is further configured to receive the updated transmission grant in a first subband of the frequency band, wherein the updated transmission grant indicates updated scheduling information associated with a second subband of the frequency band, and wherein the first subband and the second subband are different.

Further embodiments of the disclosure include an apparatus comprising means for communicating with a second wireless communication device, a first transmission grant for a transmission opportunity (TXOP) in a frequency band; means for performing medium sensing for the TXOP; and means for transmitting, to the second wireless communication device, an updated transmission grant for the TXOP based on at least the first transmission grant and a medium sensing.

The apparatus further includes wherein the means for performing the medium sensing is further configured to detect a reservation signal for the TXOP. The apparatus further includes wherein the means for performing the medium sensing is further configured to detect a reservation signal for communicating in a first link direction during the TXOP, wherein the first transmission grant and the updated transmission grant are for communicating in a second link direction, and wherein the first link direction and the second link direction are different. The apparatus further includes means for transmitting, to the second wireless communication device in the frequency band, data during the TXOP based on the updated transmission grant. The apparatus further includes wherein the means for communicating the first transmission grant is further configured to transmit, to the second wireless communication device, the first transmission grant. The apparatus further includes wherein the means for communicating the first transmission grant is further configured to receive, from the second wireless communication device, the first transmission grant. The apparatus further includes wherein the apparatus is a user equipment. The apparatus further includes means for generating the updated transmission grant by modifying scheduling information in the first transmission grant based on at least the medium sensing. The apparatus further includes wherein the updated transmission grant includes at least one of a subband allocation in the frequency band, a modulation coding scheme (MCS), a transmission power, or a transmission rank that is different from the first transmission grant. The apparatus further includes wherein the means for transmitting the updated transmission grant is further configured to transmit the updated transmission grant in another frequency band. The apparatus further includes wherein the TXOP includes a designated time period for an updated transmission grant transmission, and wherein the means for transmitting the updated transmission grant is further configured to transmit the updated transmission grant in the frequency band during the designated time period. The apparatus further includes wherein the medium sensing is for a transmission period of the TXOP, and wherein the means for transmitting the updated transmission grant is further configured to transmit the updated transmission grant in the frequency band during the transmission period. The apparatus further includes wherein the means for transmitting the updated transmission grant is further configured to transmit the updated transmission grant in a first subband of the frequency band, wherein the updated transmission grant indicates updated scheduling information associated with a second subband of the frequency band, and wherein the first subband and the second subband are different.

Further embodiments of the disclosure include an apparatus comprising means for communicating with a second wireless communication device, a first transmission grant for a transmission opportunity (TXOP) in a frequency band; and means for receiving, from the second wireless communication device, an updated transmission grant for the TXOP based on a medium sensing for the TXOP.

The apparatus further includes means for receiving, from the second wireless communication device, data in the frequency band during the TXOP based on the updated transmission grant. The apparatus further includes wherein the means for communicating the first transmission grant is further configured to transmit, to the second wireless communication device, the first transmission grant. The apparatus further includes wherein the means for communicating the first transmission grant is further configured to receive, from the second wireless communication device, the first transmission grant. The apparatus further includes wherein the updated transmission grant includes at least one of a subband allocation in the frequency band, a modulation coding scheme (MCS), a transmission power, or a transmission rank that is different from the first transmission grant. The apparatus further includes wherein the means for receiving the updated transmission grant is further configured to receive the updated transmission grant in another frequency band. The apparatus further includes wherein the TXOP includes a designated time period for an updated transmission grant transmission, and wherein the means for receiving the updated transmission grant is further configured to receive the updated transmission grant in the frequency band during the designated time period. The apparatus further includes wherein the medium sensing is for a transmission period of the TXOP, and wherein the means for receiving the updated transmission grant is further configured to receive the updated transmission grant in the frequency band during the transmission period. The apparatus further includes wherein the means for receiving the updated transmission grant is further configured to receive the updated transmission grant in a first subband of the frequency band, wherein the updated transmission grant indicates updated scheduling information associated with a second subband of the frequency band, and wherein the first subband and the second subband are different.