Patent Description:
<CIT> relates to a listen before talk operation and discloses an adaptive contention window size.

<NPL>, discusses issues on channel access procedures for NR-U, including LBE-based LBT and FBE-based LBT.

Aspects of the invention are set out in the appended set of claims.

<FIG>, <FIG>, <FIG>, <FIG>, <FIG>, <FIG> and <FIG> represent unclaimed aspects.

Examples of processors include microprocessors, microcontrollers, graphics processing units (CPUs), central processing units (CPUs), application processors, digital signal processors (DSPs), reduced instruction set computing (RISC) processors, systems on a chip (SoC), baseband processors, field programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functionality described throughout this disclosure.

Accordingly, in one or more example aspects, the functions described may be implemented in hardware, software, or any combination thereof.

The third backhaul links <NUM> may be wired or wireless.

There may be overlapping geographic coverage areas <NUM><NUM>.

Tire base station <NUM> and the UE <NUM> may each include a plurality of antennas, such as antenna elements, antenna panels, and/or antenna arrays to facilitate the beamforming.

The EPC <NUM> may include a Mobility Management Entity (MME) <NUM>, other MMEs <NUM>, a Serving Gateway <NUM>. a Multimedia Broadcast Multicast Service (MBMS) Gateway <NUM>, a Broadcast Multicast Service Center (BM-SC) <NUM>, and a Packet Data Network (PDN) Gateway <NUM>.

The base station may include and/or be referred to as a gNB. Node B, eNB, an access point, a base transceiver station. a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS), an extended service set (ESS), a transmit reception point (TRP), or some other suitable terminology. Some of the UEs <NUM><NUM> may be referred to as IoT devices (e.g., parking meter, gas pump, toaster, vehicles, heart monitor, etc.).

Referring again to <FIG>, in certain aspects, the UE <NUM> may include a UE LBT component <NUM> configured to receive a pre-grant for a downlink transmission from a base station, the pre-grant indicating a clear channel assessment (CCA) length based on a contention window size associated at least with a burst length of the downlink transmission; to perform, after receiving the pre-grant, a CCA based on the CCA length; to transmit an acknowledgment of the pre-grant (APG) to the base station when the CCA is successful; and to receive the downlink transmission from the base station in response to the APG. The UE LBT component <NUM> may also be configured to receive an uplink grant from a base station after a clear channel assessment (CCA) of the base station; and to transmit an uplink transmission to the base station in response to the uplink grant, where the CCA is based on a contention window associated at least with a burst length for the uplink transmission.

Still referring to <FIG>, in other aspects, the base station <NUM>/<NUM> may include a base station LBT component <NUM> configured to transmit a pre-grant for a downlink transmission to a user equipment (UE), the pre-grant indicating a clear channel assessment (CCA) length based on a contention window size associated at least with a burst length of the downlink transmission; to receive an acknowledgment of the pre-grant (APG) from the UE when a CCA of the UE based on the CCA length is successful; and to send the downlink transmission to the UE in response to the APG. The base station LBT component <NUM> may also be configured to perform a clear channel assessment (CCA) based on a contention window associated at least with a burst length for an uplink transmission; to transmit an uplink grant to a user equipment (UE) when the CCA is successful; and to receive the uplink transmission from the UE in response to the uplink grant.

Although the following description may be focused on <NUM> NR. the concepts described herein may be applicable to other similar areas, such as LTE. LTE-A, CDMA, GSM, and other wireless technologies.

The <NUM>/NR frame structure may be FDD in which for a particular set of subcarriers (carrier system bandwidth), subframes within the set of subcarriers are dedicated for either DL or UL. or may be TDD in which for a particular set of subcarriers (carrier system bandwidth), subframes within the set of subcarriers are dedicated for both DL and UL.

For slot configuration <NUM>, different numerologies <NUM> to <NUM> allow for <NUM>. <NUM>, and <NUM> slots, respectively, per subframe. <FIG> provide an example of slot configuration <NUM> with <NUM> symbols per slot and numerology µ=<NUM> with <NUM> slots per subframe. The slot duration is <NUM>, the subcarrier spacing is <NUM>, and the symbol duration is approximately <NUM>.

The UE may transmit DM-RS for the physical uplink control channel (PUCCH) and DM-RS for the physical uplink shared channel (PUSCII).

The PUCCH carries uplink control information (UCI), such as scheduling requests, a channel quality indicator (CQI), a precoding matrix indicator (PM1), a rank indicator (RI), and HARQ ACK/NACK feedback.

Layer <NUM> includes a radio resource control (RRC) layer, and layer <NUM> includes a service data adaptation protocol (SOAP) layer, a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, and a medium access control (MAC) layer. The controller/processor <NUM> provides RRC layer functionality associated with broadcasting of system information (e.g., MIB, SIBs), RRC connection control (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release), inter radio access technology (RAT) mobility, and measurement configuration for UE measurement reporting: PDCP layer functionality associated with header compression / decompression, security (ciphering, deciphering, integrity protection, integrity verification), and handover support functions; RLC layer functionality associated with the transfer of upper layer packet data units (PDUs), error correction through ARQ, concatenation, segmentation, and reassembly of RLC service data units (SDUs), re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto transport blocks (TBs), demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization.

Layer <NUM>, which includes a physical (PHY) layer, may include error detection on the transport channels, forward error correction (FEC) coding-decoding of the transport channels, interleaving, rate matching, mapping onto physical channels, modulation/demodulation of physical channels, and MIMO antenna processing.

IP packets from the controller processor <NUM> may be provided to the EPC <NUM>. The controller/processor <NUM> is also responsible for error detection using an ACK. and/or NACK protocol to support HARQ operations.

At least one of the TX processor <NUM>, the RX processor <NUM>, and the controller/processor <NUM> may be configured to perform aspects in connection with UE LBT component <NUM> of <FIG>.

At least one of the TX processor <NUM>, the RX processor <NUM>, and the controller/processor <NUM> may be configured to perform aspects in connection with base station LBT component <NUM> of <FIG>.

In millimeter wave (mmW) links, transmitters and receivers observe different interference patterns due to the highly directional nature of transmissions. As a result, a listen-before-talk (LBT) procedure is generally used to protect the reception of data from interference by other nodes. In LBT, a receiver (e.g. a UE or base station) applies a clear channel assessment (CCA) check before using a channel. The CCA utilizes at least energy detection to determine the presence or absence of other signals on a channel in order to determine if a channel is occupied or clear, respectively. After gaining channel access via a successful LBT operation, the receiver reserves the channel so that other nodes sense the channel to be occupied and therefore refrain from transmitting on the channel. As a result, the data received by the UE or base station may be protected from interference upon gaining access to the channel. Moreover, unnecessary backoff during LBT may be avoided and the receiver may be protected.

Channel access schemes may be classified into several categories, without LBT (Category <NUM>) and with LBT (Categories <NUM>-<NUM>). In Category <NUM> LBT, the UE or base station applies LBT without a random back-off. That is, the duration of time that the channel is sensed to be idle before transmitting on the channel is deterministic (not random). In Category <NUM> LBT and Category <NUM> LBT, the UE or base station applies LBT with a random back-off with a contention window of fixed size or variable size, respectively. In this procedure, the UE or base station draws a random number N within a contention window. The size of the contention window is specified by the minimum and maximum value of N. The size of the contention window is fixed in Category <NUM> LBT, and the size of the contention window can be varied when drawing the random number in Category <NUM> LBT. For example, the contention window size in Category <NUM> LBT may be varied based on a channel access priority class (CAPC) or Quality of Service (QoS) of traffic. The random number N is used in the LBT procedure to determine the duration of time that the channel is sensed to be idle before transmitting on the channel.

In Category <NUM> LBT, the UE or base station applies CCA to detect whether the channel is idle over a fixed period of time. If the channel is sensed busy, the UE or base station refrains from accessing the channel. Otherwise, the UE or base station proceeds to access the channel for a channel occupancy time (COT). In contrast, in Category <NUM> and <NUM> LBT (also referred to as long LBT), if the initial CCA is unsuccessful, the UE or base station further applies an extended CCA (eCCA) to detect whether the channel is idle over a random period of time corresponding to the drawn random number within the contention window. The UE or base station waits a defer period (e.g. equal to the period of time for the initial CCA), and then senses whether the channel is busy during the random period of time. If the channel is sensed busy, the UE or base station refrains from accessing the channel and may repeat the eCCA process. Otherwise, the UE or base station proceeds to access the channel for the COT.

Generally, when the UE is receiving downlink data, the base station performs Category <NUM> LBT and, if successful, transmits a downlink grant scheduling a downlink transmission to the UE. However, although the base station may sense a clear channel due to lack of interference of the base station, the UE may still experience interference and thus may not successfully receive the downlink grant or transmission from the base station. Therefore, to allow the UE to confirm the receiver side channel is clear for reception, the base station may send a pre-grant (PG) to the UE. which is a control signaling message that triggers the UE to perform Category <NUM> LBT (including eCCA). When the UE receives the PG, the UE performs eCCA and if low or no interference is detected as a result, the UE sends an acknowledgment to the pre-grant (APG) to the base station. The base station may determine from the APG that the UE is in a safe position to receive data, and the base station may subsequently send the downlink grant and downlink transmission in a downlink burst accordingly to the UE. Otherwise, if a high amount of interference is detected, the UE refrains from sending APG (thus declining to receive the scheduling) and the base station determines not to send the downlink burst.

<FIG> illustrates an example diagram <NUM> of a UE <NUM> receiving a downlink burst from a base station <NUM> after sending an APG in response to a PG. The base station performs a CCA <NUM> (e.g. Category <NUM> LBT) to determine if the channel is clear for transmission. If the CCA <NUM> is successful, the base station sends a PG <NUM> to the UE. After receiving the PG, the UE then performs an eCCA <NUM> (e.g. Category <NUM> LBT) to determine if the channel is clear for transmission. If the eCCA <NUM> is successful, the UE transmits an APG <NUM> to the base station. When the base station receives the APG, the base station again performs a CCA <NUM> (e.g. Category <NUM> LBT) to determine if the channel is clear for transmission, and if the CCA <NUM> is successful, the base station sends a downlink burst <NUM> (including a downlink grant and a downlink transmission) to the UE. After receiving the downlink transmission, the UE performs a CCA <NUM> (e.g. Category <NUM> LBT) to determine if the channel is clear for transmission, and if the CCA <NUM> is successful, the UE sends an acknowledgment (ACK)/non-acknowledgment (NACK) feedback <NUM> to the base station depending on whether the downlink transmission is successfully received.

However, in certain situations, the base station may not receive an APG from the UE. For example, although the UE receives the PG, the UE may fail the Category <NUM> LBT CCA for APG transmission due to the presence of an interfering transmission (e.g. caused by a jammer). That is, when contending with the jammer for the channel, the UE may fail the CCA and therefore not transmit the APG to the base station. In such case, if the base station does not receive the APG from the UE, the base station will consider the failure to receive the APG an indication that the UE detected a jammer and therefore cannot receive the pre-granted downlink burst. In another example, the UE may not receive the PG, e.g., due to an ongoing transmission from a jammerwhich interfered with the UE's reception of the PG, or due to link budget constraints, beam management limitations, or control channel rate control restrictions.

For example, <FIG> illustrates an example diagram <NUM> of a UE <NUM> served by a base station <NUM> and an aggressor base station <NUM> serving another UE (not shown). Similar to the example described above with respect to <FIG>, generally the base station <NUM> may perform CCA <NUM> (e.g. Category <NUM> LBT) and send a PG <NUM> to the UE if the CCA is successful, and the UE may perform eCCA <NUM> (e.g. Category <NUM> LBT) and send an APG <NUM> to the base station if the CCA is successful. If the base station receives the APG, the base station may perform CCA <NUM> (e.g. Category <NUM> LBT) and send a DL data burst <NUM> to the UE if the CCA is successful, and the UE may perform CCA <NUM> (e.g. Category <NUM> LBT) and send an ACK/NACK feedback <NUM> to the base station if the CCA is. successful. However, in the case where the aggressor base station <NUM> simultaneously sends its own transmission <NUM> to the other UE which interferes with the transmissions of the UE <NUM>, the base station <NUM> may fail to receive the APG <NUM> from the UE. While the base station <NUM> may not be able to distinguish whether failure to receive the APG from the UE was due to failure by the UE to receive the PG or due to failure by the UE to perform the eCCA. the base station <NUM> may omit sending the downlink burst due to the lack of receiving APG in either event.

In the examples described above, Category <NUM> LBT may be effective to minimize collisions in sub-<NUM> operation by randomizing the starting time for transmitting on a channel. For example, by having a large contention window, there may be a low probability that a receiver (e.g. the UE <NUM>) may draw the same random number as other nodes, and thus the nodes would likely have different random starting positions in eCCA. Moreover, if other nodes draw a larger random number than the receiver, the receiver's earlier transmission would serve to block the interfering transmissions of other nodes, minimizing chances of collision.

However, in mmW environments, collision may not necessarily be avoided by randomizing the starting time of each node for transmitting on the channel. For example, narrow beams are generally used for transmitting and receiving in mmW, and therefore less nodes may interfere with the receiver (e.g. UE <NUM>). As a result, the receiver and those nodes may be less likely to draw random numbers in eCCA at the same time. Moreover, having a large contention window to reduce collision probability of a large number of nodes may not necessarily be as efficient as in sub-<NUM> operation, since the effective node density may be reduced due to less interfering nodes in mmW. As a result, smaller contention windows may be effectively used for Category <NUM> LBT in mmW environments.

Yet, although smaller contention windows (e.g. one slot contention windows, also referred to as one-shot LBT) may serve to effectively measure high interference levels in mmW environments (since the same interference level would be sensed from one or multiple measurements although with a small difference in accuracy), larger contention windows may serve to provide higher confidence that interference will be less likely to occur in the near future at the time the receiver (e.g. UE <NUM>) is receiving the downlink burst. When transmissions are received in bursts, interference activity may have a time correlation to the observation slots in the contention window, and therefore the receiver may determine with different levels of confidence whether future interference may occur in the next burst(s). For example, if the receiver measures that X observation slots have no interference, the receiver may determine that the next Y ms will also have no interference. This time correlation may degrade over time (e.g. if Y1 < Y2, the next Y1 ms will be more likely to have no interference than the next Y2 ms). Moreover, higher confidence levels may be determined from larger contention windows (e.g. if X1 > X2, the next Y ms will be more likely to have no interference based on a similar observation in X1 slots than in X2 slots).

Therefore, to improve LBT in mmW environments based on the aforementioned time correlation, the present disclosure allows the receiver (e.g. UE <NUM> for downlink or base station <NUM> for uplink) performing long LBT to associate the size of the contention window with the burst length of the received transmission. For example, the receiver may perform eCCA with a larger contention window when the burst length is larger, and with a smaller contention window when the burst length is shorter. Moreover, based on the aforementioned time correlation, the present disclosure allows the receiver to adjust the maximum burst length and/or contention window size for performing long LBT in subsequent receptions. In this way, the eCCA and/or maximum COT may be adjusted to account for changes in interference activity at the receiver.

For DL bursts, the base station may indicate to the UE in the PG how long the UE should perform long LBT. The base station may indicate a CCA length based on a contention window size associated at least with the burst length of the downlink transmission in the PG. For example, the base station may indicate the random number (e.g. the back off or count down) in the PG. Alternatively or additionally, the base station may indicate the contention window size in the PG. The UE may determine the size of the contention window based on an association of the burst length with the contention window. The association may be preconfigured by a network (e.g. core network <NUM>) or configured by the base station. For example, if the base station sends a DL transmission having a burst length of <NUM>, the associated contention window may be [<NUM> to <NUM>], while if the base station sends a DL transmission having a burst length of <NUM>, the associated contention window may be [<NUM> to <NUM>]. As a result, when performing eCCA, the UE may draw a random number between <NUM> and <NUM> or between <NUM> and <NUM> depending on the burst length of the downlink data. Other examples of burst lengths and associated contention windows are possible.

<FIG> illustrates an example diagram <NUM> of a UE <NUM> performing different size LBTs after receiving different lengths of downlink bursts from a base station <NUM>. The base station sends a PG <NUM> that indicates information <NUM> regarding an eCCA to be performed by the UE. For example, the PG may indicate a CCA length based on a contention window size associated with at least a burst length of an upcoming downlink transmission <NUM>. In this example, the base station may configure the burst length of the downlink transmission <NUM> to be <NUM>. The UE then performs eCCA <NUM> after receiving the PG. For example, the UE may determine a contention window associated with the <NUM> burst length to be [<NUM> to <NUM>] based on a configured association between burst lengths and contention window sizes, and the UE may draw a large random number (e.g. the indicated CCA length) within the contention window. If eCCA is successful (e.g. the UE senses the channel is idle during the number of observation slots corresponding to the drawn random number), the UE transmits an APG <NUM> to the base station. After receiving the APG, the base station sends the downlink transmission <NUM> to the UE.

Subsequently (or alternatively), the base station may send a PG <NUM> that indicates information <NUM> regarding another eCCA to be performed by the UE. For example, the PG may indicate a CCA length based on a contention window size associated with at least a burst length of an upcoming downlink transmission <NUM>. In this example, the base station may configure the burst length of the downlink transmission <NUM> to be <NUM>. The UE then performs cCCA <NUM> after receiving the PG. For example, the UE may determine a contention window associated with the <NUM> burst length to be [<NUM> to <NUM>] based on a configured association between burst lengths and contention window sizes, and the UE may draw a random number (e.g. the indicated CCA length) within the contention window which is smaller than in the previous example. Thus, the number of observation slots the UE measures when performing eCCA <NUM> is smaller than in eCCA <NUM>. If eCCA is successful, the UE transmits an APG <NUM> to the base station. After receiving the APG, the base station sends the downlink transmission <NUM> to the UE.

Lastly (or alternatively), the base station may send a PG <NUM> that indicates information <NUM> regarding another eCCA to be performed by the UE. For example, the PG may indicate a CCA length based on a contention window size associated with at least a burst length of an upcoming downlink transmission <NUM>. In this example, the base station may configure the burst length of the downlink transmission <NUM> to be <NUM>. The UE then performs eCCA <NUM> after receiving the PG. For example, the UE may determine a contention window associated with the <NUM> burst length to be [<NUM> to <NUM>] based on a configured association between burst lengths and contention window sizes, and the UE may draw a random number (e.g. the indicated CCA length) within the contention window which is smaller than in both previous examples. Thus, the number of observation slots the UE measures when performing eCCA <NUM> is smaller than in eCCAs <NUM> and <NUM>. If eCCA is successful, the UE transmits an APG <NUM> to the base station. After receiving the APG, the base station sends the downlink transmission <NUM> to the UE.

For UL bursts, the base station performs long LBT prior to sending an uplink grant that schedules an uplink transmission with a configured burst length from the UE. The base station may determine the size of the contention window at least based on an association of the burst length of the uplink transmission with the contention window. The association may be preconfigured by a network (e.g. core network <NUM>) or configured by the base station. For example, if the UE sends an UL transmission having a burst length of <NUM>, the associated contention window may be [<NUM> to <NUM>] in one example, while if the UE sends an UL transmission having a burst length of <NUM>, the associated contention window may be [<NUM> to <NUM>] in another example. As a result, when performing eCCA, the base station may draw a random number between <NUM> and <NUM> or between <NUM> and <NUM> depending on the burst length of the uplink data in these examples. Other examples of burst lengths and associated contention windows are possible.

<FIG> illustrates an example diagram <NUM> of a base station <NUM> performing different size LBTs prior to sending uplink grants scheduling different lengths of uplink bursts from a UE <NUM>. The base station may determine a burst length of a planned uplink transmission <NUM>. For example, the base station may configure the burst length of the uplink transmission <NUM> to be <NUM>. The base station then performs eCCA <NUM> after determining the burst length. For example, the base station may determine a contention window associated with the <NUM> burst length to be [<NUM> to <NUM>] at least based on a configured association between burst lengths and contention window sizes, and the base station may draw a large random number within the contention window. If eCCA is successful (e.g. the base station senses the channel is idle during the number of observation slots corresponding to the drawn random number), the base station transmits an uplink grant <NUM> to the UE. The base station then receives the uplink transmission <NUM> from the UE.

Subsequently (or alternatively), the base station may determine a burst length of another planned uplink transmission <NUM>. For example, the base station may configure the burst length of the uplink transmission <NUM> to be <NUM>. The base station then performs eCCA <NUM> after determining the burst length. For example, the base station may determine a contention window associated with the <NUM> burst length to be [<NUM> to <NUM>] at least based on a configured association between burst lengths and contention window sizes, and the base station may draw a random number within the contention window which is smaller than in the previous example. Thus, the number of observation slots the base station measures when performing eCCA <NUM> may be smaller than in eCCA <NUM>. If eCCA is successful, the base station transmits an uplink grant <NUM> to the UE. The base station then receives the uplink transmission <NUM> from the UE.

Lastly (or alternatively), the base station may determine a burst length of another planned uplink transmission <NUM>. For example, the base station may configure the burst length of the uplink transmission <NUM> to be <NUM>. The base station then performs eCCA <NUM> after determining the burst length. For example, the base station may determine a contention window associated with the <NUM> burst length to be [<NUM> to <NUM>] at least based on a configured association between burst lengths and contention window sizes, and the base station may draw a random number within the contention window which is smaller than in both previous examples. Thus, the number of observation slots the base station measures when performing eCCA <NUM> may be smaller than in eCCAs <NUM> and <NUM>. If eCCA is successful, the base station transmits an uplink grant <NUM> to the UE. The base station then receives the uplink transmission <NUM> from the UE.

In the above examples, the receiver (e.g. UE <NUM> or base station <NUM>) performs LBT with different size contention windows depending on the burst length of the upcoming transmission (downlink or uplink). Generally, the larger the contention window size (e.g. the more measurements that determine whether the channel is clear), the more confidence the receiver may have that the channel will be clear for a larger amount of time in the future. Therefore, larger contention windows may be associated with larger downlink or uplink bursts, and similarly, smaller contention windows may be associated with smaller downlink or uplink bursts. However, notwithstanding the confidence that an upcoming downlink or uplink burst will be clear, interference activity at the receiver may still occur which may cause the receiver to fail to successfully decode the transmission. In such cases, the receiver may notify the transmitter of the error event (e.g. that the transmission was unsuccessfully received), by sending NACK feedback.

To address these error events, the base station may adjust the maximum downlink or uplink burst length (e.g. maximum COT) and/or the size of the contention window, and the receiver (e.g. the UE for downlink or the base station for uplink) may apply the adjusted maximum burst length or the adjusted contention window when performing LBT for receiving a subsequent transmission. The maximum burst length or contention window may be adjusted based on the feedback from the error event. For example, after the UE (e.g. UE <NUM>) receives a downlink transmission from the base station, the UE may send an ACK/NACK feedback to the base station indicating which slot(s) in the downlink transmission were successfully received (ACK) and unsuccessfully received (NACK), and the base station may adjust the maximum downlink burst length or contention window depending on the feedback received. Similarly, in another example, after the base station (e.g. base station <NUM>) receives an uplink transmission from the UE, the base station may determine which slot(s) in the uplink transmission were successfully received or unsuccessfully received, and the base station may adjust the maximum uplink burst length or contention window accordingly.

When determining which slot(s) in the downlink transmission or uplink transmission (e.g. the COT) are successfully or unsuccessfully received, the base station applies a reference duration to the transmission which includes the slot(s) of the transmission to be tested (e.g. for NACK). Although placing the reference duration at the beginning of the COT may facilitate testing for current collision, such placement may not be as effective as at the end of the COT when testing for confidence or likelihood of no future collisions (based on the aforementioned time correlation). Therefore, in the present disclosure, the base station applies the reference duration to the end of the COT. For example, when the UE receives a PDSCH transmission, the UE may determine whether it successfully or unsuccessfully decodes the last slot in the PDSCH transmission, and sends ACK/NACK feedback indicating whether that slot the PDSCH transmission is ACK or NACK. The base station may then determine whether the feedback corresponding to the last slot in the PDSCH transmission is ACK or NACK, and adjusts the maximum COT for subsequent downlink transmissions or the contention window for the UE to perform subsequent eCCA accordingly. Similarly, when the UE sends a PUSCH transmission, the base station may determine whether it successfully or unsuccessfully decodes the last slot in the PUSCH transmission, and adjusts the maximum COT for subsequent uplink transmissions or the contention window for the base station to perform subsequent eCCA accordingly. After receiving the PUSCH transmission, the base station may send feedback to the UE by toggling (for ACK) or not toggling (for NACK) a new data indicator (NDI) in a subsequent uplink grant.

When the receiver determines the decoding result of the PDSCH or PUSCH in the reference duration of the COT, the base station may adjust the maximum COT length and/or the contention window size. In one example, the base station may not change the maximum COT length (e.g. the maximum burst length for a subsequent transmission will be the same as for a prior transmission), but the base station may change the size of the contention window depending on the error event. For instance, if the reference duration is one slot and indicates NACK, or if the reference duration is multiple slots and at least a threshold number of those slots indicates NACK, the base station may increase (e.g. double) the contention window size for subsequent LBT. In contrast, if the reference duration is one slot and indicates ACK, or if the reference duration is multiple slots and at least a threshold number of those slots indicates ACK. the base station may reduce (e.g. reset to the minimum) the contention window size for subsequent LBT.

In another example, the base station may not change the contention window size, but the base station may change the maximum COT length depending on the error event. For instance, if the reference duration is one slot and indicates NACK, or if the reference duration is multiple slots and at least a threshold number of those slots indicates NACK, the base station may reduce (e.g. halve) the contention window size for subsequent LBT. In contrast, if the reference duration is one slot and indicates ACK, or if the reference duration is multiple slots and at least a threshold number of those slots indicates ACK, the base station may increase (e.g. reset to the maximum) the contention window size for subsequent LBT.

In a further example, the base station may combine the prior two examples by adjusting both the maximum COT length and size of the contention window based on the error event as described above.

<FIG> illustrate example diagrams <NUM>, <NUM> of a UE <NUM>, <NUM> performing LBTs with adjusted contention window sizes after receiving different downlink transmissions from a base station <NUM>, <NUM> with the same maximum burst length (<FIG>), or with the same contention window size after receiving different downlink transmissions from the base station with an adjusted maximum burst length (<FIG>). Initially, the base station sends a PG <NUM>, <NUM> that indicates information regarding an eCCA to be performed by the UE. For example, the PG may indicate a CCA length based on a contention window size associated with at least a maximum burst length of an upcoming downlink transmission <NUM>, <NUM>. In this example, the base station may configure the maximum burst length (e.g. maximum COT) of the downlink transmission <NUM>, <NUM> to be <NUM>. The UE then performs eCCA <NUM>, <NUM> after receiving the PG. For example, the UE may determine a contention window associated with the <NUM> maximum burst length to be [<NUM> to <NUM>] based on a configured association between maximum burst lengths and contention window sizes, and the UE may draw a large random number (e.g. the indicated CCA length) within the contention window. If eCCA is successful (e.g. the UE senses the channel is idle during the number of observation slots corresponding to the drawn random number), the UE transmits an APG <NUM>, <NUM> to the base station. After receiving the APG, the base station sends the downlink transmission <NUM>, <NUM> to the UE.

When the UE receives the downlink transmission <NUM>, <NUM>, the UE determines whether it successfully or unsuccessfully decodes the data within reference duration <NUM>, <NUM>. For example, reference duration <NUM>, <NUM> may be the last slot of the PDSCH. In this example, the UE failed to successfully decode the data in this reference duration (e.g. due to new interference activity from an aggressor base station), and therefore the UE transmits a NACK feedback <NUM>, <NUM> to the base station. When the base station receives the NACK feedback from the UE, the base station determines that the UE failed to receive the data likely due to interference, and therefore the base station in the example of <FIG> increases the contention window size for subsequent LBT while keeping the same maximum burst length for subsequent downlink transmissions, and in the example of <FIG> decreases the maximum burst length for subsequent downlink transmissions while keeping the same contention window size for subsequent LBT. The base station may then send the adjusted contention window size or adjusted maximum burst length to the UE (e.g. in the PG).

Subsequently, the base station may send a PG <NUM>, <NUM> that indicates information regarding another eCCA to be performed by the UE. For example, the PG may indicate a CCA length based on a contention window size associated with at least the adjusted maximum burst length for an upcoming downlink transmission <NUM> or a CCA length based on the adjusted contention window size for performing eCCA prior to receiving the upcoming downlink transmission <NUM>. In the example of <FIG>. the base station may again configure the maximum burst length of the downlink transmission <NUM> to be <NUM>. The UE then performs eCCA <NUM> after receiving the PG. For example, the UE may determine the contention window associated with the <NUM> burst length to be [<NUM> to <NUM>] based on the adjusted contention window size, and the UE may draw a random number (e.g. the indicated CCA length) within the contention window which is larger than in the previous example. If eCCA is successful, the UE transmits an APG <NUM> to the base station. After receiving the APG, the base station sends die downlink transmission <NUM> to the UE.

In the example of <FIG>, the base station may adjust the maximum burst length of the downlink transmission to be <NUM>, while keeping the contention window size the same. The UE then performs eCCA <NUM> after receiving the PG. For example, the UE may determine the contention window associated with the <NUM> burst length to remain at [<NUM> to <NUM>] based on the adjusted maximum burst length, and the UE may draw a random number (e.g. the indicated CCA length) within the contention window similar to the previous example. If eCCA is successful, the UE transmits an APG <NUM> to the base station. After receiving the APG, the base station sends the downlink transmission <NUM> to the UE.

When the UE receives the downlink transmission <NUM>, <NUM> the UE determines whether it successfully or unsuccessfully decodes the data within the reference duration. In this example, the UE succeeds in decoding the data in the reference duration (e.g. due to lack of interference activity from an aggressor base station), and therefore the UE transmits an ACK feedback <NUM>, <NUM> to the base station. When the base station receives the ACK feedback from the UE, the base station determines that the UE successfully received the data likely due to absence of interference, and therefore the base station in the example of <FIG> resets the contention window size for subsequent LBT while keeping the same maximum burst length for subsequent downlink transmissions, and in the example of <FIG> increases the maximum burst length for subsequent downlink transmissions while keeping the same contention window size for subsequent LBT. The base station may then send the adjusted contention window size or adjusted maximum burst length to the UE (e.g. in the PG).

Lastly, the base station may send a PG <NUM>, <NUM> that indicates information regarding another eCCA to be performed by the UE. For example, the PG may indicate a CCA length based on a contention window size associated with at least the adjusted maximum burst length for an upcoming downlink transmission <NUM> or a CCA length based on the adjusted contention window size for performing eCCA prior to receiving the upcoming downlink transmission <NUM>. In the example of <FIG>, the base station may again configure the maximum burst length of the downlink transmission <NUM> to be <NUM>. The UE then performs eCCA <NUM> after receiving the PG. For example, the UE may determine the contention window associated with the <NUM> burst length to be [<NUM> to <NUM>] based on the adjusted contention window size, and the UE may draw a random number (e.g. the indicated CCA length) within the contention window which is smaller than in the previous example. If eCCA is successful, the UE transmits an APG <NUM> to the base station. After receiving the APG, the base station sends the downlink transmission <NUM> to the UE.

In the example of <FIG>, the base station may adjust the maximum burst length of the downlink transmission to be <NUM>, while keeping the contention window size the same. The UE then performs eCCA <NUM> after receiving the PG. For example, the UE may determine the contention window associated with the <NUM> burst length to remain at [<NUM> to <NUM>] based on the adjusted maximum burst length, and the UE may draw a random number (e.g. the indicated CCA length) within the contention window similar to the previous examples. If eCCA is successful, the UE transmits an APG <NUM> to the base station. After receiving the APG, the base station sends the downlink transmission <NUM> to the UE.

Thus, <FIG> illustrate downlink examples where the contention window size or maximum burst length may be adjusted based on interference activity. The above described process is similar for uplink. For example, referring to <FIG>, the base station <NUM> may perform LBT with adjusted contention window sizes prior to sending uplink grants <NUM>, <NUM>, <NUM> scheduling uplink bursts <NUM>, <NUM>, <NUM> from a UE <NUM> with the same maximum burst length (similar to <FIG>), or with the same contention window size prior to sending uplink grants <NUM>, <NUM>, <NUM> scheduling uplink bursts <NUM>, <NUM>, <NUM> from the UE with an adjusted maximum burst length (similar to <FIG>). The base station may determine a maximum burst length of a planned uplink transmission <NUM>, <NUM>, <NUM> and perform eCCA <NUM>, <NUM>, <NUM> after determining the maximum burst length. If eCCA is successful, the base station transmits the uplink grant <NUM>, <NUM>, <NUM> to the UE and then receives the uplink transmission <NUM>, <NUM>, <NUM> from the UE. When the base station receives the uplink transmission, the base station determines whether it successfully or unsuccessfully decodes the data within the reference duration (e.g. at the end of the COT). Depending on whether the base station succeeds or fails to decode the data in the reference duration, the base station may adjust the contention window size for subsequent LBT while keeping the same maximum burst length for subsequent uplink transmissions (similar to <FIG>) or adjust the maximum burst length for subsequent uplink transmissions while keeping the same contention window size for subsequent LBT (similar to <FIG>).

<FIG> is a flowchart <NUM> of a method of wireless communication. The method may be performed by a UE (e.g., the UE <NUM>. <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, which may include the memory <NUM> and which may be the entire UE <NUM> or a component of the UE <NUM>, such as the TX processor <NUM>, the RX processor <NUM>, and/or the controller/processor <NUM>). Optional aspects are illustrated in dashed lines. The method allows for improved receiver-based LBT for downlink transmissions.

At <NUM>, the UE receives a pre-grant for a downlink transmission from a base station, the pre-grant indicating a CCA length based on a contention window size associated at least with a burst length of the downlink transmission.

At <NUM>, the UE performs, after receiving the pre-grant, a CCA based on the CCA length. The CCA length may comprise a backoff within the contention window for the UE to apply when performing the CCA.

At <NUM>, the UE transmits an acknowledgment of the pre-grant (APG) to the base station when the CCA is successful.

At <NUM>, the UE receives the downlink transmission from the base station in response to the APG.

At <NUM>, the UE transmits an acknowledgment (ACK)/non-acknowledgment (NACK) feedback to the base station in response to the downlink transmission.

At <NUM>, the UE performs a subsequent CCA prior to receiving a subsequent downlink transmission from the base station. At least one of the subsequent CCA or the subsequent downlink transmission may be based on the ACK/NACK feedback associated with a reference duration at an end of the burst length for the downlink transmission. The downlink transmission may be a physical downlink shared channel (PDSCH), and the reference duration may be a last slot of the PDSCH.

In one example, the subsequent downlink transmission may include a same maximum burst length as a maximum burst length for the downlink transmission, and the subsequent CCA may be performed based on an adjusted contention window associated with the same maximum burst length, the adjusted contention window being based on the ACK/NACK feedback associated with the reference duration. The adjusted contention window may be increased when the ACK/NACK feedback associated with the reference duration is a NACK, and the adjusted contention window may be decreased when the ACK/NACK feedback associated with the reference duration is an ACK.

In another example, the subsequent downlink transmission may include an adjusted maximum burst length, the adjusted maximum burst length being based on the ACK/NACK feedback associated with the reference duration. The subsequent CCA may be performed based on a same contention window as the contention window for the downlink transmission. The adjusted maximum burst length may be decreased when the ACK/NACK feedback associated with the reference duration is a NACK, and the adjusted maximum burst length may be increased when the ACK/NACK feedback associated with the reference duration is an ACK.

In a further example, the subsequent downlink transmission may include an adjusted maximum burst length, the subsequent CCA may be performed based on an adjusted contention window associated with the adjusted maximum burst length, and the adjusted maximum burst length and the adjusted contention window may be based on the ACK/NACK feedback associated with the reference duration.

<FIG> is a flowchart <NUM> of a method of wireless communication. The method may be performed by a UE (e.g., the UE <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, which may include the memory <NUM> and which may be the entire UE <NUM> or a component of the UE <NUM>, such as the TX processor <NUM>, the RX processor <NUM>, and/or the controller/processor <NUM>). Optional aspects are illustrated in dashed lines. The method allows for improved receiver-based LBT for uplink transmissions.

At <NUM>, the UE receives an uplink grant from a base station after a clear channel assessment (CCA) of the base station.

At <NUM>, the UE transmits an uplink transmission to the base station in response to the uplink grant, where the CCA is based on a contention window associated at least with a burst length for the uplink transmission.

At <NUM>, the UE receives a feedback indication from the base station in response to the uplink transmission.

At <NUM>, the UE receives, after a subsequent CCA of the base station, another uplink grant from the base station for a subsequent uplink transmission. At least one of the subsequent CCA or the subsequent uplink transmission may be based on the feedback indication associated with a reference duration at an end of the burst length for the uplink transmission. The uplink transmission may be a physical uplink shared channel (PUSCH), the reference duration may be a last slot of the PUSCH, and the feedback indication may be based on a new data indicator (NDI) in the another uplink grant for a hybrid automatic repeat request (HARQ) process.

In one example, the subsequent uplink transmission may include a same maximum burst length as a maximum burst length for the uplink transmission, and the subsequent CCA may be based on an adjusted contention window associated with the same maximum burst length, the adjusted contention window being based on the feedback indication associated with the reference duration. The adjusted contention window may be increased when the feedback indication associated with the reference duration is a NACK, and the adjusted contention window may be decreased when the feedback indication associated with the reference duration is an ACK.

In another example, the subsequent uplink transmission may include an adjusted maximum burst length, the adjusted maximum burst length being based on the feedback indication associated with the reference duration. The subsequent CCA may be based on a same contention window as the contention window for the uplink transmission. The adjusted maximum burst length may be decreased when the feedback indication associated with the reference duration is a NACK, and the adjusted maximum burst length may be increased when the feedback indication associated with the reference duration is an ACK.

In a further example, the subsequent uplink transmission may include an adjusted maximum burst length, the subsequent CCA may be based on an adjusted contention window associated with the adjusted maximum burst length, and the adjusted maximum burst length and the adjusted contention window may be based on the feedback indication associated with the reference duration.

<FIG> is a flowchart <NUM> of a method of wireless communication. The method may be performed by a base station <NUM> (e.g., the base station <NUM>/<NUM>, <NUM>,<NUM>,<NUM>,<NUM>, <NUM>, <NUM>, <NUM>, which may include the memory <NUM> and which may be the entire base station <NUM> or a component of the base station <NUM>, such as the TX processor <NUM>, the RX processor <NUM>, and/or the controller/processor <NUM>). Optional aspects are illustrated in dashed lines. The method allows for improved receiver-based LBT for downlink transmissions.

At <NUM>, the base station transmits a pre-grant for a downlink transmission to a user equipment (UE), the pre-grant indicating a CCA length based on a contention window size associated at least with a burst length of the downlink transmission.

At <NUM>, the base station receives an acknowledgment of the pre-grant (APG) from the UE when a CCA of the UE based on the CCA length is successful. The CCA length may comprise a backoff within the contention window for the CCA of the UE.

At <NUM>, the base station sends the downlink transmission to the UE in response to the APG.

At <NUM>, the base station receives an acknowledgment (ACK)/non-acknowledgment (NACK) feedback from the UE in response to the downlink transmission.

At <NUM>, the base station transmits a subsequent downlink transmission to the UE after a subsequent CCA of the UE. At least one of the subsequent CCA or the subsequent downlink transmission may be based on the ACK/NACK feedback associated with a reference duration at an end of the burst length for the downlink transmission. The downlink transmission may be a physical downlink shared channel (PDSCH), and the reference duration may be a last slot of the PDSCH.

In one example, the subsequent downlink transmission may include a same maximum burst length as a maximum burst length for the downlink transmission, and the subsequent CCA may be based on an adjusted contention window associated with the same maximum burst length, the adjusted contention window being based on the ACK/NACK feedback associated with the reference duration. The adjusted contention window may be increased when the ACK/NACK feedback associated with the reference duration is a NACK, and the adjusted contention window may be decreased when the ACK/NACK feedback associated with the reference duration is an ACK.

In another example, the subsequent downlink transmission may include an adjusted maximum burst length, the adjusted maximum burst length being based on the ACK/NACK feedback associated with the reference duration. The subsequent CCA may be based on a same contention window as the contention window for the downlink transmission. The adjusted maximum burst length may be decreased when the ACK/NACK feedback associated with the reference duration is a NACK, and the adjusted maximum burst length may be increased when the ACK/NACK feedback associated with the reference duration is an ACK.

In a further example, the subsequent downlink transmission may include an adjusted maximum burst length, the subsequent CCA may be based on an adjusted contention window associated with the adjusted maximum burst length, and the adjusted maximum burst length and the adjusted contention window may be based on the ACK/NACK feedback associated with the reference duration.

<FIG> is a flowchart <NUM> of a method of wireless communication. The method may be performed by a base station <NUM> (e.g., the base station <NUM>/<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>,<NUM>,<NUM>, which may include the memory <NUM> and which may be the entire base station <NUM> or a component of the base station <NUM>, such as the TX processor <NUM>, the RX processor <NUM>, and/or the controller/processor <NUM>). Optional aspects are illustrated in dashed lines. The method allows for improved receiver-based LBT for uplink transmissions.

At <NUM>, the performs a clear channel assessment (CCA) based on a contention window associated at least with a burst length for an uplink transmission.

At <NUM>, the base station transmits an uplink grant to a user equipment (UE) when the CCA is successful.

At <NUM>, the base station receives the uplink transmission from the UE in response to the uplink grant.

At <NUM>, the base station transmits a feedback indication to the UE in response to the uplink transmission.

At <NUM>, the base station performs a subsequent CCA prior to sending another uplink grant to the UE for a subsequent uplink transmission. At least one of the subsequent CCA or the subsequent uplink transmission may be based on the feedback indication associated with a reference duration at an end of the burst length for the uplink transmission. The uplink transmission may be a physical uplink shared channel (PUSCH), the reference duration may be a last slot of the PUSCH, and the feedback indication may be based on a new data indicator (NDT) in the another uplink grant for a hybrid automatic repeat request (HARQ) process.

In one example, the subsequent uplink transmission may include a same maximum burst length as a maximum burst length for the uplink transmission, and the subsequent CCA may be performed based on an adjusted contention window associated with the same maximum burst length, the adjusted contention window being based on the feedback indication associated with the reference duration. The adjusted contention window may be increased when the feedback indication associated with the reference duration is a NACK, and the adjusted contention window may be decreased when the feedback indication associated with the reference duration is an ACK.

In another example, the subsequent uplink transmission may include an adjusted maximum burst length, the adjusted maximum burst length being based on the feedback indication associated with the reference duration. The subsequent CCA may be performed based on a same contention window as the contention window for the uplink transmission. The adjusted maximum burst length may be decreased when the feedback indication associated with the reference duration is a NACK, and the adjusted maximum burst length may be increased when the feedback indication associated with the reference duration is an ACK.

In a further example, the subsequent uplink transmission may include an adjusted maximum burst length, the subsequent CCA may be performed based on an adjusted contention window associated with the adjusted maximum burst length, and the adjusted maximum burst length and the adjusted contention window may be based on the feedback indication associated with the reference duration.

<FIG> is a conceptual data flow diagram <NUM> illustrating the data flow between different means/components in an exemplary apparatus <NUM>. The apparatus may be a UE (e.g., UE <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) in wireless communication with base station <NUM>.

The apparatus includes a reception component <NUM> that receives downlink communication from the base station <NUM>. The reception component <NUM> may be configured to receive signals and/or other information from other devices including, e.g., base station <NUM>. The signals/information received by the reception component <NUM> may be provided to one or more components of the apparatus <NUM> for further processing and use in performing various operations in accordance with the methods discussed supra including the processes of the aforementioned flowcharts <NUM> and <NUM>. Thus, via the reception component <NUM>, the apparatus <NUM> and/or one or more components therein receive signals and/or other information (e.g., such as downlink data for the apparatus <NUM> and/or other control signaling) from the base station <NUM> as discussed supra and also discussed more specifically infra.

In some aspects, the reception component <NUM> is configured to receive, from the BS, receive a pre-grant for a downlink transmission from a base station, e.g., as described in connection with block <NUM> of <FIG>. In some aspects, , the pre-grant indicates a CCA length based on a contention window size associated at least with a burst length of a downlink transmission, e.g., as described in connection with block <NUM> of <FIG>. In some aspects, the reception component <NUM> is also configured to receive a downlink transmission from the base station in response to the APG, e.g., as described in connection with block <NUM> of <FIG>. In some aspects, the reception component <NUM> is also configured to receive, from the BS, a subsequent downlink transmission. In some aspects, the subsequent downlink transmission includes a same maximum burst length as a maximum burst length for the downlink transmission. In some aspects, the subsequent downlink transmission is based on the ACK/NACK feedback associated with a reference duration at an end of the burst length for the downlink transmission. In some aspects, the downlink transmission is a PDSCH, and the reference duration is a last slot of the PDSCH. In some aspects, the reception component <NUM> is configured to receive an uplink grant from a base station after a CCA of the base station, e.g., as described in connection with block <NUM> of <FIG>. In some aspects, the reception component <NUM> is configured to receive, after a subsequent CCA of the base station, another uplink grant from the base station for a subsequent uplink transmission, e.g., as described in connection with block <NUM> of <FIG>. In some aspects, the subsequent downlink transmission includes an adjusted maximum burst length. In some aspects, the adjusted maximum burst length is based on the feedback indication, such as the ACK/NACK feedback, associated with the reference duration. For example, the adjusted maximum burst length is decreased when the ACK/NACK feedback associated with the reference duration is a NACK. In another example, the adjusted maximum burst length is increased when the ACK/NACK feedback associated with the reference duration is an ACK.

The apparatus includes a clear channel assessment component <NUM> configured to perform, after receiving the pre-grant, a CCA based on the CCA length, e.g., as described in connection with block <NUM> of <FIG>. In some aspects, the CCA length comprises a backoff within the contention window size for the UE to apply when performing the CCA. In some aspects, the clear channel assessment component <NUM> performs the CCA is based on a contention window associated at least with a burst length for the uplink transmission. The clear channel assessment component <NUM> is also configured to perform a subsequent CCA prior to receiving a subsequent downlink transmission from the base station, e.g., as described in connection with block <NUM> of <FIG>. In some aspects, the subsequent CCA is performed based on an adjusted contention window associated with the same maximum burst length. In other aspects, the subsequent CCA is performed based on a same contention window size as the contention window size for the downlink transmission. In other aspects, the subsequent CCA is based on a same contention window as the contention window for the uplink transmission. In some aspects, the subsequent CCA is based on the ACK/NACK feedback associated with a reference duration at an end of the burst length for the downlink transmission.

The apparatus includes an acknowledgment pre-grant component <NUM> configured to transmit an acknowledgment of the pre-grant (APG) to the base station when the CCA is successful, e.g., as described in connection with block <NUM> of <FIG>.

The apparatus includes a feedback component <NUM> configured to receive a feedback indication from the base station in response to the uplink transmission, e.g., as described in connection with block <NUM> of <FIG>. In some aspects, the feedback indication is based on a new data indicator (NDI) in the another uplink grant for a hybrid automatic repeat request (HARQ) process.

The apparatus includes a contention window component <NUM> configured to determine a contention window. In some aspects, the contention window component <NUM> is also configured to determine an adjusted contention window. In some aspects, the adjusted contention window is based on the ACK/NACK feedback associated with the reference duration. For example, the adjusted contention window is increased when the ACK/NACK feedback associated with the reference duration is a NACK. In another example, the adjusted contention window is decreased when the ACK/NACK feedback associated with the reference duration is an ACK.

The apparatus includes a transmission component <NUM> that transmits uplink communication to the base station <NUM>. The transmission component <NUM> may be configured to transmit various messages to one or more external devices, e.g., including the base station <NUM>, in accordance with the methods disclosed herein. The messages/signals to be transmitted may be generated by one or more other components as discussed above, or the messages/signals to be transmitted may be generated by the transmission component <NUM> under the direction/control of the one or more other components discussed supra. Thus, in various configurations, via the transmission component <NUM>, the apparatus <NUM> and/or one or more components therein transmit signals and/or other information (e.g., such as uplink data, control messages and/or other signals) to external devices such as the base station <NUM>. In some aspects, the transmission component <NUM> is configured to transmit an acknowledgment (ACK)/non-acknowledgment (NACK) feedback to the base station in response to the downlink transmission, e.g.. as described in connection with block <NUM> of <FIG>. In some aspects, the transmission component <NUM> is configured to transmit a subsequent downlink transmission. In some aspects, the subsequent uplink transmission includes an adjusted maximum burst length. In some aspects, the subsequent uplink transmission includes a same maximum burst length as a maximum burst length for the uplink transmission. In some aspects, the transmission component <NUM> is configured to transmitting an uplink transmission to the base station in response to the uplink grant, e.g., as described in connection with block <NUM> of <FIG>. In some aspects, the uplink transmission is a PUSCH, in which the reference duration is a last slot of the PUSCH.

<FIG> is a diagram <NUM> illustrating an example of a hardware implementation for an apparatus <NUM>' employing a processing system <NUM>. The processing system <NUM> may be implemented with a bus architecture, represented generally by the bus <NUM>. The bus <NUM> may include any number of interconnecting buses and bridges depending on the specific application of the processing system <NUM> and the overall design constraints. The bus <NUM> links together various circuits including one or more processors and/or hardware components, represented by the processor <NUM>, the components <NUM>, <NUM>, <NUM>, <NUM>,<NUM>, <NUM> and the computer-readable medium / memory <NUM>. The bus <NUM> may also link various other circuits such as timing sources, peripherals, voltage regulators, and power management circuits, which are well known in the art, and therefore, will not be described any further.

The processing system <NUM> may be coupled to a transceiver <NUM>. The transceiver <NUM> is coupled to one or more antennas <NUM>. The transceiver <NUM> provides a means for communicating with various other apparatus over a transmission medium. The transceiver <NUM> receives a signal from the one or more antennas <NUM>, extracts information from the received signal, and provides the extracted information to the processing system <NUM>, specifically the reception component <NUM>. In addition, the transceiver <NUM> receives information from the processing system <NUM>, specifically the transmission component <NUM>, and based on the received information, generates a signal to be applied to the one or more antennas <NUM>. The processing system <NUM> includes a processor <NUM> coupled to a computer-readable medium / memory <NUM>. The processor <NUM> is responsible for general processing, including the execution of software stored on the computer-readable medium / memory <NUM>. The software, when executed by the processor <NUM>, causes the processing system <NUM> to perform the various functions described supra for any particular apparatus. The computer-readable medium / memory <NUM> may also be used for storing data that is manipulated by the processor <NUM> when executing software. The processing system <NUM> further includes at least one of the components <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>. The components may be software components running in the processor <NUM>, resident/stored in the computer readable medium / memory <NUM>. one or more hardware components coupled to the processor <NUM>, or some combination thereof. The processing system <NUM> may be a component of the UE <NUM> and may include the memory <NUM> and/or at least one of the TX processor <NUM>. the RX processor <NUM>, and the controller/processor <NUM>.

In one configuration, the apparatus <NUM>/<NUM>' for wireless communication includes means for receiving a pre-grant for a downlink transmission from a base station. In some aspects, the pre-grant indicates a clear channel assessment (CCA) length based on a contention window size associated at least with a burst length of the downlink transmission. The apparatus <NUM>/<NUM>' also includes means for performing, after receiving the pre-grant, a CCA based on the CCA length. The apparatus <NUM>/<NUM>' also includes means for transmitting an acknowledgment of the pre-grant (APG) to the base station when the CCA is successful. The apparatus <NUM>/<NUM>' also includes means for receiving the downlink transmission from the base station in response to the APG.

In another configuration, the apparatus <NUM>/<NUM>' for wireless communication includes means for receiving an uplink grant from a base station after a CCA of the base station. The apparatus <NUM>/<NUM>' also includes means for transmitting an uplink transmission to the base station in response to the uplink grant. In some aspects, the CCA is based on a contention window associated at least with a burst length for the uplink transmission.

<FIG> is a conceptual data flow diagram <NUM> illustrating the data flow between different means/components in an exemplary apparatus <NUM>. The apparatus may be a base station (e.g., BS <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) in wireless communication with UE <NUM>.

The apparatus <NUM> includes a burst length component <NUM> configured to determine a maximum burst length. In some aspects, the subsequent uplink transmission includes an adjusted maximum burst length. In some aspects, the subsequent uplink transmission includes a same maximum burst length as a maximum burst length for the uplink transmission. In other aspects, the burst length component <NUM> is configured to determine an adjusted maximum burst length. In some aspects, a subsequent downlink transmission includes an adjusted maximum burst length. In some aspects, the adjusted maximum burst length is based on the feedback indication associated with the reference duration. For example, the adjusted maximum burst length is based on the ACK/NACK feedback associated with the reference duration. In some aspects, the adjusted maximum burst length is decreased when the feedback indication associated with the reference duration is a NACK. For example, the adjusted maximum burst length is decreased when the ACK/NACK feedback associated with the reference duration is a NACK. In other aspects, the adjusted maximum burst length is increased when the feedback indication associated with the reference duration is an ACK. For example, the adjusted maximum burst length is increased when the ACK/NACK feedback associated with the reference duration is an ACK.

The apparatus <NUM> includes a feedback indication component <NUM> configured to receive an acknowledgment (ACK)/non-acknowledgment (NACK) feedback from the UE in response to a downlink transmission, e.g., as described in connection with block <NUM> of <FIG>. In some aspects, the feedback indication component <NUM> is configured to transmit a feedback indication to the UE in response to the uplink transmission, e.g., as described in connection with block <NUM> of <FIG>. In some aspects, the feedback indication is based on a new data indicator (NDI) in the another uplink grant for a hybrid automatic repeat request (HARQ) process. In some aspects, the adjusted maximum burst length and the adjusted contention window are based on the feedback indication associated with the reference duration. For example, the adjusted maximum burst length and the adjusted contention window are based on the ACK/NACK feedback associated with the reference duration.

The apparatus <NUM> includes a clear channel assessment component <NUM> configured to perform a CCA based on a contention window associated at least with a burst length for an uplink transmission, e.g., as described in connection with block <NUM> of <FIG>. In some aspects, the clear channel assessment component <NUM> is also configured to perform a subsequent CCA prior to sending another uplink grant to the UE for a subsequent uplink transmission, e.g., as described in connection with block <NUM> of <FIG>. In some aspects, at least one of the subsequent CCA or the subsequent uplink transmission is based on the feedback indication associated with a reference duration at an end of the burst length for the uplink transmission. In some aspects, the subsequent CCA is performed based on an adjusted contention window associated with the same maximum burst length. In other aspects, the subsequent CCA is performed based on a same contention window as the contention window for the uplink transmission. In some aspects, the subsequent CCA is based on a same contention window size as the contention window size for the downlink transmission. In some aspects, the subsequent CCA is performed based on an adjusted contention window associated with the adjusted maximum burst length.

The apparatus <NUM> includes an uplink grant component <NUM> configured to transmit an uplink grant to a UE when the CCA is successful, e.g., as described in connection with block <NUM> of <FIG>.

The apparatus <NUM> includes a contention window component <NUM> configured to determine an adjusted contention window. In some aspects, the adjusted contention window is based on the feedback indication associated with the reference duration. For example, the adjusted contention window is based on the ACK/NACK feedback associated with the reference duration. In some aspects, the adjusted contention window is increased when the feedback indication associated with the reference duration is a NACK. For example, the adjusted contention window is increased when the ACK/NACK feedback associated with the reference duration is a NACK. In other aspects, the adjusted contention window is decreased when the feedback indication associated with the reference duration is an ACK. For example, the adjusted contention window is decreased when the ACK/NACK feedback associated with the reference duration is an ACK.

The apparatus <NUM> includes a pre-grant component <NUM> configured to transmit a pre-grant for a downlink transmission to a UE, e.g., as described in connection with block <NUM> of <FIG>. In some aspects, the pre-grant indicates a CCA length based on a contention window size associated at least with a burst length of the downlink transmission. In some aspects, the CCA length includes a backoff within the contention window size for the CCA of the UE.

The apparatus <NUM> includes a transmission component <NUM> that transmits uplink communication to the UE <NUM>. The transmission component <NUM> may be configured to transmit various messages to one or more external devices, e.g., including the UE <NUM>, in accordance with the methods disclosed herein. The messages/signals to be transmitted may be generated by one or more other components as discussed above, or the messages/signals to be transmitted may be generated by the transmission component <NUM> under the direction/control of the one or more other components discussed supra. Thus, in various configurations, via the transmission component <NUM>, the apparatus <NUM> and/or one or more components therein transmit signals and/or other information (e.g., such as downlink data, control messages and/or other signals) to external devices such as the UE <NUM>. In some aspects, the transmission component <NUM> is configured to send the downlink transmission to the UE in response to the APG, e.g., as described in connection with block <NUM> of <FIG>. In some aspects, the transmission component <NUM> is configured to transmit a subsequent downlink transmission to the UE after a subsequent CCA of the UE, e.g., as described in connection with block <NUM> of <FIG>. In some aspects, the subsequent downlink transmission includes a same maximum burst length as a maximum burst length for the downlink transmission. In some aspects, at least one of the subsequent CCA or the subsequent downlink transmission is based on the ACK/NACK feedback associated with a reference duration at an end of the burst length for the downlink transmission. In some aspects, the downlink transmission is a PDSCH, and the reference duration is a last slot of the PDSCH.

The apparatus. <NUM> includes a reception component <NUM> that receives uplink communication from the UE <NUM>. The reception component <NUM> may be configured to receive signals and/or other information from other devices including, e.g., UE <NUM>. The signals/information received by the reception component <NUM> may be provided to one or more components of the apparatus <NUM> for further processing and use in performing various operations in accordance with the methods discussed supra including the processes of the aforementioned flowcharts <NUM> and <NUM>. Thus, via the reception component <NUM>, the apparatus <NUM> and/or one or more components therein receive signals and/or other information (e.g., such as uplink data for the apparatus <NUM> and/or other control signaling) from the UE <NUM> as discussed supra and also discussed more specifically infra. In some aspects, the reception component <NUM> is configured to receive the uplink transmission from the UE in response to the uplink grant, e.g., as described in connection with block <NUM> of <FIG>. In some aspects, the uplink transmission is a PUSCH. In some aspects, the reference duration is a last slot of the PUSCH. In some aspects, the reception component <NUM> is configured to receive an acknowledgment of the pre-grant (APG) from the UE when a CCA of the UE based on the CCA length is successful, e.g., as described in connection with block <NUM> of <FIG>.

The apparatus <NUM> may include additional components that perform each of the blocks of the algorithm in the aforementioned flowcharts of <FIG> and <FIG>.

<FIG> is a diagram <NUM> illustrating an example of a hardware implementation for an apparatus <NUM>' employing a processing system <NUM>. The processing system <NUM> may be implemented with a bus architecture, represented generally by the bus <NUM>. The bus <NUM> may include any number of interconnecting buses and bridges depending on the specific application of the processing system <NUM> and the overall design constraints. The bus <NUM> links together various circuits including one or more processors and/or hardware components, represented by the processor <NUM>, the components <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and the computer-readable medium / memory <NUM>. The bus <NUM> may also link various other circuits such as timing sources, peripherals, voltage regulators, and power management circuits, which are well known in the art, and therefore, will not be described any further.

The processing system <NUM> may be coupled to a transceiver <NUM>. The transceiver <NUM> is coupled to one or more antennas <NUM>. The transceiver <NUM> provides a means for communicating with various other apparatus over a transmission medium. The transceiver <NUM> receives a signal from the one or more antennas <NUM>, extracts information from the received signal, and provides the extracted information to the processing system <NUM>, specifically the reception component <NUM>. In addition, the transceiver <NUM> receives information from the processing system <NUM>, specifically the transmission component <NUM>, and based on the received information, generates a signal to be applied to the one or more antennas <NUM>. The processing system <NUM> includes a processor <NUM> coupled to a computer-readable medium / memory <NUM>. The processor <NUM> is responsible for general processing, including the execution of software stored on the computer-readable medium / memory <NUM>. The software, when executed by the processor <NUM>, causes the processing system <NUM> to perform the various functions described supra for any particular apparatus. The computer-readable medium / memory <NUM> may also be used for storing data that is manipulated by the processor <NUM> when executing software. The processing system <NUM> further includes at least one of the components <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>. The components may be software components running in the processor <NUM>, resident/stored in the computer readable medium % memory <NUM>, one or more hardware components coupled to the processor <NUM>, or some combination thereof. The processing system <NUM> may be a component of the UE <NUM> and may include the memory <NUM> and/or at least one of the TX processor <NUM>, the RX processor <NUM>, and the controller/processor <NUM>.

In one configuration, the apparatus <NUM>/<NUM>' for wireless communication includes means for transmitting a first signal in uplink (UL) resources to a first base station, means for receiving a second signal in downlink (DL) resources concurrently with the transmission of the first signal to the first base station, the received second signal including interference associated with the transmitted first signal, means for determining a level of the interference received in the second signal that is associated with the transmitted first signal, and means for transmitting information associated with the determined level of interference to the first base station.

In another configuration, the apparatus <NUM>/<NUM>' for wireless communication includes means for performing a clear channel assessment (CCA) based on a contention window associated at least with a burst length for an uplink transmission. The apparatus <NUM>/<NUM>' also includes means for transmitting an uplink grant to a user equipment (UE) when the CCA is successful. The apparatus <NUM>/<NUM>' also includes means for receiving the uplink transmission from the UE in response to the uplink grant.

As described supra, the processing system <NUM> may include the TX Processor <NUM>, the RX Processor <NUM>, and the controller-processor <NUM>.

Claim 1:
A method (<NUM>) of wireless communication at a user equipment, UE, comprising:
receiving (<NUM>) a pre-grant for a downlink transmission from a network entity, the pre-grant indicating a clear channel assessment, CCA, length based on a contention window size associated at least with a burst length of the downlink transmission;
performing (<NUM>), after receiving the pre-grant, a CCA based on the CCA length ;
transmitting (<NUM>) an acknowledgment of the pre-grant, APG, to the network entity when the CCA is successful; and
receiving (<NUM>) the downlink transmission from the network entity in response to the APG.