WO2021179114A1

WO2021179114A1 - Reference duration for contention window size (cws) adjustment

Info

Publication number: WO2021179114A1
Application number: PCT/CN2020/078398
Authority: WO
Inventors: Changlong Xu; Xiaoxia Zhang; Jing Sun
Original assignee: Qualcomm Inc
Current assignee: Qualcomm Inc
Priority date: 2020-03-09
Filing date: 2020-03-09
Publication date: 2021-09-16
Anticipated expiration: 2022-09-09

Abstract

Techniques for contention-based access. A method for wireless communication, includes determining whether a data transmission using channel repetition is successful, the data transmission being during at least one reference duration (505), adjusting a size associated with a contention window (CW) based on the determination (510), and communicating with a wireless node during the CW having the adjusted size (515).

Description

REFERENCE DURATION FOR CONTENTION WINDOW SIZE (CWS) ADJUSTMENT

BACKGROUND

Field of the Disclosure

Aspects of the present disclosure relate to wireless communications, and more particularly, to techniques for contention-based access.

Description of Related Art

Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, broadcasts, etc. These wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, etc. ) . Examples of such multiple-access systems include 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) systems, LTE Advanced (LTE-A) systems, code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single-carrier frequency division multiple access (SC-FDMA) systems, and time division synchronous code division multiple access (TD-SCDMA) systems, to name a few.

These multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate on a municipal, national, regional, and even global level. New radio (e.g., 5G NR) is an example of an emerging telecommunication standard. NR is a set of enhancements to the LTE mobile standard promulgated by 3GPP. NR is designed to better support mobile broadband Internet access by improving spectral efficiency, lowering costs, improving services, making use of new spectrum, and better integrating with other open standards using OFDMA with a cyclic prefix (CP) on the downlink (DL) and on the uplink (UL) . To these ends, NR supports beamforming, multiple-input multiple-output (MIMO) antenna technology, and carrier aggregation.

However, as the demand for mobile broadband access continues to increase, there exists a need for further improvements in NR and LTE technology. Preferably, these improvements should be applicable to other multi-access technologies and the telecommunication standards that employ these technologies.

SUMMARY

The systems, methods, and devices of the disclosure each have several aspects, no single one of which is solely responsible for its desirable attributes. Without limiting the scope of this disclosure as expressed by the claims which follow, some features will now be discussed briefly. After considering this discussion, and particularly after reading the section entitled “Detailed Description” one will understand how the features of this disclosure provide advantages that include improved contention-based access.

Certain aspects provide a method for wireless communication. The method generally includes determining whether a data transmission using channel repetition is successful, the data transmission being during at least one reference duration, adjusting a size associated with a contention window (CW) based on the determination, and communicating with a wireless node during the CW having the adjusted size.

Certain aspects provide an apparatus for wireless communication. The apparatus generally includes a processing system configured to determine whether a data transmission using channel repetition is successful, the data transmission being during at least one reference duration, adjust a size associated with a contention window (CW) based on the determination, and a transceiver configured to communicate with a wireless node during the CW having the adjusted size.

Certain aspects provide an apparatus for wireless communication. The apparatus generally includes means for determining whether a data transmission using channel repetition is successful, the data transmission being during at least one reference duration, means for adjusting a size associated with a contention window (CW) based on the determination, and means for communicating with a wireless node during the CW having the adjusted size.

Certain aspects provide a computer-readable medium having instructions stored thereon to cause a processor to determine whether a data transmission using channel repetition is successful, the data transmission being during at least one reference duration, adjust a size associated with a contention window (CW) based on the determination, and communicate with a wireless node during the CW having the adjusted size.

Aspects of the present disclosure provide means for, apparatus, processors, and computer-readable mediums for performing the methods described herein.

To the accomplishment of the foregoing and related ends, the one or more aspects comprise the features hereinafter fully described and particularly pointed out in the claims. The following description and the appended drawings set forth in detail certain illustrative features of the one or more aspects. These features are indicative, however, of but a few of the various ways in which the principles of various aspects may be employed.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above-recited features of the present disclosure can be understood in detail, a more particular description, briefly summarized above, may be had by reference to aspects, some of which are illustrated in the drawings. It is to be noted, however, that the appended drawings illustrate only certain typical aspects of this disclosure and are therefore not to be considered limiting of its scope, for the description may admit to other equally effective aspects.

FIG. 1 is a block diagram conceptually illustrating an example telecommunications system, in accordance with certain aspects of the present disclosure.

FIG. 2 is a block diagram conceptually illustrating a design of an example a base station (BS) and user equipment (UE) , in accordance with certain aspects of the present disclosure.

FIGs. 3A and 3B illustrate a listen-before-talk (LBT) communication protocol, in accordance with certain aspects of the present disclosure.

FIG. 4 illustrates multiple LBT bandwidths, each having a reference duration associated therewith, in accordance with certain aspects of the present disclosure.

FIG. 5 is a flow diagram illustrating example operations for wireless communication, in accordance with certain aspects of the present disclosure.

FIG. 6 illustrates diagrams showing transmissions using slot aggregation, in accordance with certain aspects of the present disclosure.

FIG. 7 illustrates diagrams showing transmissions using multiple transmit-receive point (TRP) , in accordance with certain aspects of the present disclosure.

FIG. 8 illustrates a communications device that may include various components configured to perform operations for the techniques disclosed herein in accordance with aspects of the present disclosure.

To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements disclosed in one aspect may be beneficially utilized on other aspects without specific recitation.

DETAILED DESCRIPTION

Aspects of the present disclosure provide apparatus, methods, processing systems, and computer readable mediums for contention-based access, and more specifically, to techniques for adjusting contention window size (CWS) based on a reference duration. For example, a transmitter device may transmit data on a data channel after a contention window (CW) and receive feedback indicating whether the data transmission was successfully decoded. Based on the feedback, the transmitter device may decide whether to adjust the CWS. For example, if the feedback is a negative acknowledgement (NACK) , the transmitter device may increase the CWS, reducing the probably of collision when transmitting data. The data transmission may be transmitted using slot aggregation or repetition across transmit-receive points (TRPs) .

A reference duration may be considered to begin at the beginning of the data transmission, otherwise referred to as a channel occupancy time (COT) . Certain aspects of the present disclosure provide techniques for determining when the reference duration ends for channel repetition (e.g., slot aggregation or repetition across TRPs) . The determination of whether a CWS is to be adjusted may be based on whether transmissions during the reference duration are successful. In one aspects, the reference duration may end at the end of the last slot of a data channel transmission with slot aggregation, or end at the end of a data channel transmission burst with slot aggregation, whichever is earlier.

The following description provides examples of adjusting contention window size based on a reference duration in communication systems, and is not limiting of the scope, applicability, or examples set forth in the claims. Changes may be made in the function and arrangement of elements discussed without departing from the scope of the disclosure. Various examples may omit, substitute, or add various procedures or components as appropriate. For instance, the methods described may be performed in an order different from that described, and various steps may be added, omitted, or combined. Also, features described with respect to some examples may be combined in some other examples. For example, an apparatus may be implemented or a method may be practiced using any number of the aspects set forth herein. In addition, the scope of the disclosure is intended to cover such an apparatus or method which is practiced using other structure, functionality, or structure and functionality in addition to, or other than, the various aspects of the disclosure set forth herein. It should be understood that any aspect of the disclosure disclosed herein may be embodied by one or more elements of a claim. The word “exemplary” is used herein to mean “serving as an example, instance, or illustration. ” Any aspect described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects.

In general, any number of wireless networks may be deployed in a given geographic area. Each wireless network may support a particular radio access technology (RAT) and may operate on one or more frequencies. A RAT may also be referred to as a radio technology, an air interface, etc. A frequency may also be referred to as a carrier, a subcarrier, a frequency channel, a tone, a subband, etc. Each frequency may support a single RAT in a given geographic area in order to avoid interference between wireless networks of different RATs. In some cases, a 5G NR RAT network may be deployed.

FIG. 1 illustrates an example wireless communication network 100 in which aspects of the present disclosure may be performed. For example, the wireless communication network 100 may be an NR system (e.g., a 5G NR network) .

As illustrated in FIG. 1, the wireless communication network 100 may include a number of base stations (BSs) 110a-z (each also individually referred to herein as BS 110 or collectively as BSs 110) and other network entities. A BS 110 may provide communication coverage for a particular geographic area, sometimes referred to as a “cell” , which may be stationary or may move according to the location of a mobile BS 110. In some examples, the BSs 110 may be interconnected to one another and/or to one or more other BSs or network nodes (not shown) in wireless communication network 100 through various types of backhaul interfaces (e.g., a direct physical connection, a wireless connection, a virtual network, or the like) using any suitable transport network. In the example shown in FIG. 1, the

BSs

110a, 110b and 110c may be macro BSs for the

macro cells

102a, 102b and 102c, respectively. The BS 110x may be a pico BS for a pico cell 102x. The BSs 110y and 110z may be femto BSs for the

femto cells

102y and 102z, respectively. A BS may support one or multiple cells. The BSs 110 communicate with user equipment (UEs) 120a-y (each also individually referred to herein as UE 120 or collectively as UEs 120) in the wireless communication network 100. The UEs 120 (e.g., 120x, 120y, etc. ) may be dispersed throughout the wireless communication network 100, and each UE 120 may be stationary or mobile. According to certain aspects, the BSs 110 and UEs 120 may be configured for adjusting contention window size based on a reference duration.

As shown in FIG. 1, the BS 110a may include a CWS manager 112. The CWS manager 112 may be configured to determine whether a data transmission (e.g., downlink data channel) using channel repetition is successful, the data transmission being during at least one reference duration; adjust a size associated with a contention window (CW) based on the determination; and communicate with a wireless node during the CW having the adjusted size, in accordance with aspects of the present disclosure. As shown in FIG. 1, the UE 120a may also include a CWS manager 122. The CWS manager 122 may be configured to determine whether a data transmission (e.g., uplink data channel) using channel repetition is successful, the data transmission being during at least one reference duration; adjust a size associated with a contention window (CW) based on the determination; and communicate with a wireless node during the CW having the adjusted size, in accordance with aspects of the present disclosure.

Wireless communication network 100 may also include relay stations (e.g., relay station 110r) , also referred to as relays or the like, that receive a transmission of data and/or other information from an upstream station (e.g., a BS 110a or a UE 120r) and sends a transmission of the data and/or other information to a downstream station (e.g., a UE 120 or a BS 110) , or that relays transmissions between UEs 120, to facilitate communication between devices.

A network controller 130 may couple to a set of BSs 110 and provide coordination and control for these BSs 110. The network controller 130 may communicate with the BSs 110 via a backhaul. The BSs 110 may also communicate with one another (e.g., directly or indirectly) via wireless or wireline backhaul.

FIG. 2 illustrates example components of BS 110a and UE 120a (e.g., in the wireless communication network 100 of FIG. 1) , which may be used to implement aspects of the present disclosure.

At the BS 110a, a transmit processor 220 may receive data from a data source 212 and control information from a controller/processor 240. The control information may be for the physical broadcast channel (PBCH) , physical control format indicator channel (PCFICH) , physical hybrid ARQ indicator channel (PHICH) , physical downlink control channel (PDCCH) , group common PDCCH (GC PDCCH) , etc. The data may be for the physical downlink shared channel (PDSCH) , etc. The processor 220 may process (e.g., encode and symbol map) the data and control information to obtain data symbols and control symbols, respectively. The transmit processor 220 may also generate reference symbols, such as for the primary synchronization signal (PSS) , secondary synchronization signal (SSS) , and cell-specific reference signal (CRS) . A transmit (TX) multiple-input multiple-output (MIMO) processor 230 may perform spatial processing (e.g., precoding) on the data symbols, the control symbols, and/or the reference symbols, if applicable, and may provide output symbol streams to the modulators (MODs) 232a-232t. Each modulator 232 may process a respective output symbol stream (e.g., for OFDM, etc. ) to obtain an output sample stream. Each modulator may further process (e.g., convert to analog, amplify, filter, and upconvert) the output sample stream to obtain a downlink signal. Downlink signals from modulators 232a-232t may be transmitted via the antennas 234a-234t, respectively.

At the UE 120a, the antennas 252a-252r may receive the downlink signals from the BS 110a and may provide received signals to the demodulators (DEMODs) in transceivers 254a-254r, respectively. Each demodulator 254 may condition (e.g., filter, amplify, downconvert, and digitize) a respective received signal to obtain input samples. Each demodulator may further process the input samples (e.g., for OFDM, etc. ) to obtain received symbols. A MIMO detector 256 may obtain received symbols from all the demodulators 254a-254r, perform MIMO detection on the received symbols if applicable, and provide detected symbols. A receive processor 258 may process (e.g., demodulate, deinterleave, and decode) the detected symbols, provide decoded data for the UE 120a to a data sink 260, and provide decoded control information to a controller/processor 280.

On the uplink, at UE 120a, a transmit processor 264 may receive and process data (e.g., for the physical uplink shared channel (PUSCH) ) from a data source 262 and control information (e.g., for the physical uplink control channel (PUCCH) from the controller/processor 280. The transmit processor 264 may also generate reference symbols for a reference signal (e.g., for the sounding reference signal (SRS) ) . The symbols from the transmit processor 264 may be precoded by a TX MIMO processor 266 if applicable, further processed by the demodulators in transceivers 254a-254r (e.g., for SC-FDM, etc. ) , and transmitted to the BS 110a. At the BS 110a, the uplink signals from the UE 120a may be received by the antennas 234, processed by the modulators 232, detected by a MIMO detector 236 if applicable, and further processed by a receive processor 238 to obtain decoded data and control information sent by the UE 120a. The receive processor 238 may provide the decoded data to a data sink 239 and the decoded control information to the controller/processor 240.

The

memories

242 and 282 may store data and program codes for BS 110a and UE 120a, respectively. A scheduler 244 may schedule UEs for data transmission on the downlink and/or uplink.

The controller/processor 280 and/or other processors and modules at the UE 120a may perform or direct the execution of processes for the techniques described herein. For example, as shown in FIG. 2, the controller/processor 240 of the BS 110a has a CWS manager 241 that may be configured for adjusting CWS, according to aspects described herein. As shown in FIG. 2, the controller/processor 280 of the UE 120a may also include a CWS manager 281 that may be configured to adjust CWS, according to aspects described herein. Although shown at the Controller/Processor, other components of the UE 120a and BS 110a may be used performing the operations described herein.

Example Techniques for Adjustment of Contention Window Size

Listen-Before-Talk (LBT) is a feature that allows for fair coexistence of wireless nodes. For example, a transmitter may first sense a medium and transmit a message if the medium is sensed to be idle. As an example, an uplink (UL) data channel (e.g., physical uplink shared channel (PUSCH) ) transmission may be performed based on an UL grant transmission via a downlink control channel. The UL grant may be transmitted by a base station (BS) . After receiving the UL grant, a scheduled UE may check to see if the medium is clear, and if so, then the UE may transmit on the uplink data channel after a contention window (CW) . The CW may span a certain number of slots selected randomly within a contention window size (CWS) spanning between a minimum CW setting CWmin and a maximum CW setting CWmax. Thus, each node that may occupy a medium may begin transmitting at a random time interval. If a transmission by a node is unsuccessful due to a collision between transmissions of two nodes, the CWS may be increased to reduce the chances of collision during a subsequence transmission opportunity.

FIGs. 3A and 3B illustrates a CW for a category-4 (CAT-4) LBT, in some aspects. As illustrated, after a channel busy period 302, a transmitter (e.g., transmitter 340 as illustrated in FIG. 3B) may begin a defer period during which the node defers any transmission. The defer period may include a defer duration of 16us, plus one or more defer time intervals (Td) , as illustrated in FIG. 3A. For example, a quantity of n defer time intervals (Td) may be implemented, n being related to a channel access priority class (CAPC) of the node, and the typical value for Td may be 9us. After the defer duration (16us and n Td) CW 306 begins. The CW 306 may have a duration of N x Td, N being a randomly selected integer uniformly distributed between 0 and a contention window size (CWS) . The CWS may be updated using feedback on a channel, as described in more detail herein. Channels without explicit feedback may use the CWS last updated by channels with explicit feedback and may use the same CAPC if such channels exist. Otherwise, such channels may use the minimum CWS (CWSmin) corresponding to the CAPC. As illustrated, a transmission 308 may occur after the CW 306. The transmission 308 may be PDSCH or PUSCH.

For CWS adjustment for transmissions including PDSCH and PUSCH, if HARQ feedback is available relative to a prior CW update, the feedback for the latest channel occupancy time (COT) for which new feedback is received may be used for CWS adjustment. For example, if a receiver 342 transmits HARQ feedback 320 in response to receiving data transmission 308 from transmitter 340, as illustrated in FIG. 3B, and the HARQ feedback 320 is acknowledge (ACK) indicating that the transmission 308 was successfully decoded, the transmitter 340 may set the CWS to a minimum CW setting (CWmin) at block 322. However, if the HARQ feedback 320 is negative ACK (NACK) indicating that the transmission was not successfully decoded, or in absence of feedback within a feedback window in which case the transmitter (e.g., BS or UE) retransmits the TB, CWS may be set to the minimum of CW × 2 + 1 or a maximum CW setting (CWmax) . In other words, if a data transmission is determined to be unsuccessful, transmitter 340 may adjust (increase) the CWS at block 322, reducing the chances of collision of transmission by different nodes. As illustrated in FIG. 3B, another data transmission 324 may occur after another CW associated with the adjusted CWS.

The feedback window (e.g., during which HARQ feedback 320 may be received) starts at the end of a reference duration and has a duration of maximum of X ms or the duration of the transmission burst from start of the reference duration + 1 ms. If the absence of other technologies in the medium cannot be guaranteed, X may be equal to 5 ms, and X may be equal to 10 ms otherwise. If a new HARQ feedback is not available, the CW may remain the same. As used herein, HARQ feedback may include any implicit methods of HARQ feedback determination.

As illustrated in FIG. 3A, a reference duration 310 may begin at the beginning of the channel occupancy (CO) (e.g., beginning of transmission 308) . The reference duration 310 is the period in which data transmission are considered for CWS adjustment. In other words, instead of considering the success of all transmissions 308 for determining whether to adjust a CWS, a transmitter may only consider whether data transmission during the reference duration 310 are successful, and perform CWS adjustment accordingly.

FIG. 4 illustrates multiple LBT bandwidths, each having a reference duration associated therewith. As illustrated, data may be transmitted during

multiple slots

402, 404, 406 on LBT BW0, and data may be transmitted on slot 408 on LBT BW 1. The reference duration for CWS adjustment is maintained per LBT bandwidth. Unicast PDSCH transmission may be punctured if part of the transmission falling in a LBT bandwidth fails LBT. For example, a transmission in slot 402 and a transmission in slot 408 may be punctured. In certain aspects, a reference duration starts at the beginning of CO, and ends at the earlier one of (1) the end of the first slot where at least one unicast downlink data channel (e.g., physical downlink shared channel (PDSCH) ) is fully transmitted, or (2) the end of the first transmission burst (e.g., by the base station) that contains unicast downlink data channel (s) fully transmitted. A data channel transmission is considered to be not fully transmitted if the data channel transmission is punctured (e.g., as is the case for transmissions in slots 402, 408) . In certain aspects, if the first transmission burst by a transmitter ends before the first slot boundary, the reference duration may ends at the end of the first transmission burst by the base station that contains unicast data channel (s) fully transmitted. However, if the CO has a unicast PDSCH, but doesn’t have any unicast PDSCH transmitted over all the resources allocated for that PDSCH, then, the duration of the first transmission burst by the transmitter within the CO that contains unicast PDSCH (s) may be the reference duration for CWS adjustment. For instance, for LBT BW0, the reference duration 410 ends at the end of the second slot 404 since the transmission in the slot 402 is punctured. For LBT BW1, since there is only transmission in slot 408, the reference duration 412 for LBT BW1 ends at the end of slot 408 even though the transmission in slot 408 is punctured.

In certain aspects, to enhance coverage, a PDSCH with slot aggregation may be introduced. A transport block (TB) may be repeated over slots, and the UE may obtain the repetition gain. A TB generally refers to the payload for a physical layer. In response to receiving the TB, the UE (e.g., receiver) may provide a single ACK/NACK to the base station (e.g., transmitter) as a feedback response. In certain aspects, the base station may use the ACK/NACK response from the UE to make a CWS adjustment. In a multiple transmit-receive point (TRP) system, inter-slot multiple TRP repetition may be used for data transmission (e.g., PDSCH) . The reference duration for CWS adjustment may be implemented for each TRP on a per-TRP basis, as described in more detail herein.

FIG. 5 is a flow diagram illustrating example operations 500 for wireless communication, in accordance with certain aspects of the present disclosure. The operations 500 may be performed, for example, by wireless node, such as a BS (e.g., the BS 110a in the wireless communication network 100) , or a UE (e.g., such as a UE 120a in the wireless communication network 100) .

Operations 500 may be implemented as software components that are executed and run on one or more processors (e.g., controller/processor 240 of FIG. 2, or controller/processor 280 of FIG. 2) . Further, the transmission and reception of signals by the BS or the UE in operations 500 may be enabled, for example, by one or more antennas (e.g., antennas 234 of FIG. 2 or antennas 252 of FIG. 2) . In certain aspects, the transmission and/or reception of signals by the BS or the UE may be implemented via a bus interface of one or more processors (e.g., controller/processor 240, or controller/processor 280 of FIG. 2) obtaining and/or outputting signals. The operations 500 may alternatively be performed, for example, by UE (e.g., such as a UE 120a in the wireless communication network 100) .

The operations 500 may begin, at block 505, by the wireless node determining whether a data transmission using channel repetition is successful, the data transmission being during at least one reference duration. The operations 500 may continue, at block 510, by the wireless node adjusting a size associated with a contention window (CW) based on the determination. At block 515, the wireless node communicates (e.g., with another wireless node) during the CW having the adjusted size.

FIG. 6 illustrates diagrams 600A and 600B showing transmissions using slot aggregation, in accordance with certain aspects of the present disclosure. As described herein, the end point of the reference duration may occur at the earlier one of (1) the end of the first slot where at least one unicast PDSCH is fully transmitted (e.g., the end of slot n) or the end of the first transmission burst by a transmitter device (e.g., BS) that contains unicast PDSCH (s) that is/are fully transmitted. Thus, as illustrated in diagram 600A, a wireless node may transmit data channels (e.g., PDSCH) on slots n, n+1, n+2, and n+3 using slot aggregation. The reference duration 602 to be used for CWS adjustment may start at the beginning of slot n corresponding to the beginning of the COT. The end of the reference duration 602 may occur at the end of slot n.

In certain aspects, the end point of a reference duration may occur at the earlier one of the end of the last slot of data channel (e.g., PDSCH) with slot aggregation or the end of the data channel (e.g., PDSCH) transmission burst with slot aggregation by the transmitter device (e.g., BS) . For example, as illustrated in diagram 600B, the reference duration 604 may begin at the beginning of slot n and end at the end of the last slot (slot n+3) of the data channel transmission using slot aggregation. While certain examples provided herein have described reference duration with respect to a downlink channel (e.g., PDSCH) to facilitate understanding, the techniques described herein for determination a reference duration may also be applied for an uplink data channel (e.g., PUSCH) with slot aggregation.

FIG. 7 illustrates diagrams 700A and 700B showing transmissions using multiple transmit-receive point (TRP) with repetition, in accordance with certain aspects of the present disclosure. As illustrated, a PDSCH may be repeated on an intra-slot basis over two TRPs. In other words, the same PDSCH may be transmitted over TRP0 and TRP1 in slot n, as shown in diagrams 700A. For example, PDSCH 704 may be transmitted in slot n on TRP 0 and PDSCH 705 may be transmitted on TRP 1, PDSCH 705 being a repeated version of PDSCH 704. For example, PDSCH 705 may be a different redundancy version of PDSCH 704. Referring to the diagram 700A, the reference duration 702A for TRP 0 may start at the beginning of the COT (e.g., the beginning of PDSCH 704 in slot n) for TRP0, as shown. In certain aspects, the end point of the reference duration 702A may occur at one of the end of the first slot where at least one unicast PDSCH is fully transmitted or the end of the first transmission burst by the BS that contains unicast PDSCH (s) that are fully transmitted. Furthermore, whether a transmission is fully transmitted may either impact all TRPs or only effect a TRP corresponding to the transmission.

In other words, a punctured frequency band on TRP 0 may only affect the reference duration of TRP 0. For example, as illustrated in diagram 700A, the reference duration 702A begins at the beginning of PDSCH 704, but ends at the end of PDSCH 706 in slot n+1 because PDSCH 704 is punctured (e.g., is not considered to be fully transmitted) . However, the punctured PDSCH 704 may only effect the reference duration of TRP 0. Therefore, the reference duration 702B may begin at the beginning of PDSCH 705 on TRP 1, and end at the end of PDSCH 705 since PDSCH 705 is not punctured (e.g., is fully transmitted) .

In other aspects, a punctured frequency band on TRP 0 may effect the reference durations of both TRP 0 and TRP 1. For example, as illustrated in diagram 700B, the PDSCH 704 in slot n is punctured (not fully transmitted) , but the PDSCH 705 in slot n is not punctured (is fully transmitted) . In this case, the reference duration 702A ends at the end of PDSCH 706 in slot n+1, and the reference duration 702B for TRP 1 ends at the end PDSCH 708 in slot n+1. In otherwords, both PDSCH 704 and PDSCH 705 are considered to be not fully transmitted for purposes of determining the reference durations for TRP 0 and TRP 1.

FIG. 8 illustrates a communications device 800 that may include various components (e.g., corresponding to means-plus-function components) configured to perform operations for the techniques disclosed herein, such as the operations illustrated in FIG. 5. The communications device 800 includes a processing system 802 coupled to a transceiver 808. The transceiver 808 is configured to transmit and receive signals for the communications device 800 via an antenna 810, such as the various signals as described herein. The processing system 802 may be configured to perform processing functions for the communications device 800, including processing signals received and/or to be transmitted by the communications device 800.

The processing system 802 includes a processor 804 coupled to a computer-readable medium/memory 812 via a bus 806. In certain aspects, the computer-readable medium/memory 812 is configured to store instructions (e.g., computer-executable code) that when executed by the processor 804, cause the processor 804 to perform the operations illustrated in FIG. 5, or other operations for performing the various techniques discussed herein for managing CWS. In certain aspects, computer-readable medium/memory 812 stores code 814 for determining whether a data transmission using channel repetition is successful, the data transmission being during at least one reference duration; code 816 for adjusting a size associated with a contention window (CW) based on the determination; and code 818 for communicating with a wireless node during the CW having the adjusted size. In certain aspects, the processor 804 has circuitry configured to implement the code stored in the computer-readable medium/memory 812. The processor 804 includes circuitry 820 for determining whether a data transmission using channel repetition is successful, the data transmission being during at least one reference duration; circuitry 824 for adjusting a size associated with a contention window (CW) based on the determination; and circuitry 826 for communicating with a wireless node during the CW having the adjusted size.

The techniques described herein may be used for various wireless communication technologies, such as NR (e.g., 5G NR) , 3GPP Long Term Evolution (LTE) , LTE-Advanced (LTE-A) , code division multiple access (CDMA) , time division multiple access (TDMA) , frequency division multiple access (FDMA) , orthogonal frequency division multiple access (OFDMA) , single-carrier frequency division multiple access (SC-FDMA) , time division synchronous code division multiple access (TD-SCDMA) , and other networks. The terms “network” and “system” are often used interchangeably. A CDMA network may implement a radio technology such as Universal Terrestrial Radio Access (UTRA) , cdma2000, etc. UTRA includes Wideband CDMA (WCDMA) and other variants of CDMA. cdma2000 covers IS-2000, IS-95 and IS-856 standards. A TDMA network may implement a radio technology such as Global System for Mobile Communications (GSM) . An OFDMA network may implement a radio technology such as NR (e.g. 5G RA) , Evolved UTRA (E-UTRA) , Ultra Mobile Broadband (UMB) , IEEE 802.11 (Wi-Fi) , IEEE 802.16 (WiMAX) , IEEE 802.20, Flash-OFDMA, etc. UTRA and E-UTRA are part of Universal Mobile Telecommunication System (UMTS) . LTE and LTE-A are releases of UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A and GSM are described in documents from an organization named “3rd Generation Partnership Project” (3GPP) . cdma2000 and UMB are described in documents from an organization named “3rd Generation Partnership Project 2” (3GPP2) . NR is an emerging wireless communications technology under development.

The techniques described herein may be used for the wireless networks and radio technologies mentioned above as well as other wireless networks and radio technologies. For clarity, while aspects may be described herein using terminology commonly associated with 3G, 4G, and/or 5G wireless technologies, aspects of the present disclosure can be applied in other generation-based communication systems.

In 3GPP, the term “cell” can refer to a coverage area of a Node B (NB) and/or a NB subsystem serving this coverage area, depending on the context in which the term is used. In NR systems, the term “cell” and BS, next generation NodeB (gNB or gNodeB) , access point (AP) , distributed unit (DU) , carrier, or transmission reception point (TRP) may be used interchangeably. A BS may provide communication coverage for a macro cell, a pico cell, a femto cell, and/or other types of cells. A macro cell may cover a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by UEs with service subscription. A pico cell may cover a relatively small geographic area and may allow unrestricted access by UEs with service subscription. A femto cell may cover a relatively small geographic area (e.g., a home) and may allow 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, etc. ) . 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.

A UE may also be referred to as a mobile station, a terminal, an access terminal, a subscriber unit, a station, a Customer Premises Equipment (CPE) , a cellular phone, a smart phone, a personal digital assistant (PDA) , a wireless modem, a wireless communication device, a handheld device, a laptop computer, a cordless phone, a wireless local loop (WLL) station, a tablet computer, a camera, a gaming device, a netbook, a smartbook, an ultrabook, an appliance, a medical device or medical equipment, a biometric sensor/device, a wearable device such as a smart watch, smart clothing, smart glasses, a smart wrist band, smart jewelry (e.g., a smart ring, a smart bracelet, etc. ) , an entertainment device (e.g., a music device, a video device, a satellite radio, etc. ) , a vehicular component or sensor, a smart meter/sensor, industrial manufacturing equipment, a global positioning system device, or any other suitable device that is configured to communicate via a wireless or wired medium. Some UEs may be considered machine-type communication (MTC) devices or evolved MTC (eMTC) devices. MTC and eMTC UEs include, for example, robots, drones, remote devices, sensors, meters, monitors, location tags, etc., that may communicate with a BS, another device (e.g., remote device) , or some other entity. A wireless node may provide, for example, connectivity for or to a network (e.g., a wide area network such as Internet or a cellular network) via a wired or wireless communication link. Some UEs may be considered Internet-of-Things (IoT) devices, which may be narrowband IoT (NB-IoT) devices.

Certain wireless networks (e.g., LTE) utilize orthogonal frequency division multiplexing (OFDM) on the downlink and single-carrier frequency division multiplexing (SC-FDM) on the uplink. OFDM and SC-FDM partition the system bandwidth into multiple (K) orthogonal subcarriers, which are also commonly referred to as tones, bins, etc. 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. For example, the spacing of the subcarriers may be 15 kHz and the minimum resource allocation (called a “resource block” (RB) ) may be 12 subcarriers (or 180 kHz) . Consequently, the nominal Fast Fourier Transfer (FFT) size may be equal to 128, 256, 512, 1024 or 2048 for system bandwidth of 1.25, 2.5, 5, 10, or 20 megahertz (MHz) , respectively. The system bandwidth may also be partitioned into subbands. For example, a subband may cover 1.08 MHz (e.g., 6 RBs) , and there may be 1, 2, 4, 8, or 16 subbands for system bandwidth of 1.25, 2.5, 5, 10 or 20 MHz, respectively. In LTE, the basic transmission time interval (TTI) or packet duration is the 1 ms subframe.

NR may utilize OFDM with a CP on the uplink and downlink and include support for half-duplex operation using TDD. In NR, a subframe is still 1 ms, but the basic TTI is referred to as a slot. A subframe contains a variable number of slots (e.g., 1, 2, 4, 8, 16, …slots) depending on the subcarrier spacing. The NR RB is 12 consecutive frequency subcarriers. NR may support a base subcarrier spacing of 15 KHz and other subcarrier spacing may be defined with respect to the base subcarrier spacing, for example, 30 kHz, 60 kHz, 120 kHz, 240 kHz, etc. The symbol and slot lengths scale with the subcarrier spacing. The CP length also depends on the subcarrier spacing. Beamforming may be supported and beam direction may be dynamically configured. MIMO transmissions with precoding may also be supported. In some examples, MIMO configurations in the DL may support up to 8 transmit antennas with multi-layer DL transmissions up to 8 streams and up to 2 streams per UE. In some examples, multi-layer transmissions with up to 2 streams per UE may be supported. Aggregation of multiple cells may be supported with up to 8 serving cells.

In some examples, access to the air interface may be scheduled. A scheduling entity (e.g., a BS) allocates resources for communication among some or all devices and equipment within its service area or cell. The scheduling entity may be responsible for scheduling, assigning, reconfiguring, and releasing resources for one or more subordinate entities. That is, for scheduled communication, subordinate entities utilize resources allocated by the scheduling entity. Base stations are not the only entities that may function as a scheduling entity. In some examples, a UE may function as a scheduling entity and may schedule resources for one or more subordinate entities (e.g., one or more other UEs) , and the other UEs may utilize the resources scheduled by the UE for wireless communication. In some examples, a UE may function as a scheduling entity in a peer-to-peer (P2P) network, and/or in a mesh network. In a mesh network example, UEs may communicate directly with one another in addition to communicating with a scheduling entity.

In some examples, two or more subordinate entities (e.g., UEs) may communicate with each other using sidelink signals. Real-world applications of such sidelink communications may include public safety, proximity services, UE-to-network relaying, vehicle-to-vehicle (V2V) communications, Internet of Everything (IoE) communications, IoT communications, mission-critical mesh, and/or various other suitable applications. Generally, a sidelink signal may refer to a signal communicated from one subordinate entity (e.g., UE1) to another subordinate entity (e.g., UE2) without relaying that communication through the scheduling entity (e.g., UE or BS) , even though the scheduling entity may be utilized for scheduling and/or control purposes. In some examples, the sidelink signals may be communicated using a licensed spectrum (unlike wireless local area networks, which typically use an unlicensed spectrum) .

The methods disclosed herein comprise one or more steps or actions for achieving the methods. The method steps and/or actions may be interchanged with one another without departing from the scope of the claims. In other words, unless a specific order of steps or actions is specified, the order and/or use of specific steps and/or actions may be modified without departing from the scope of the claims.

As used herein, a phrase referring to “at least one of” a list of items refers to any combination of those items, including single members. As an example, “at least one of: a, b, or c” is intended to cover a, b, c, a-b, a-c, b-c, and a-b-c, as well as any combination with multiples of the same element (e.g., a-a, a-a-a, a-a-b, a-a-c, a-b-b, a-c-c, b-b, b-b-b, b-b-c, c-c, and c-c-c or any other ordering of a, b, and c) .

As used herein, the term “determining” encompasses a wide variety of actions. For example, “determining” may include calculating, computing, processing, deriving, investigating, looking up (e.g., looking up in a table, a database or another data structure) , ascertaining and the like. Also, “determining” may include receiving (e.g., receiving information) , accessing (e.g., accessing data in a memory) and the like. Also, “determining” may include resolving, selecting, choosing, establishing and the like.

The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects. Thus, the claims are not intended to be limited to the aspects shown herein, but is to be accorded the full scope consistent with the language of the claims, wherein reference to an element in the singular is not intended to mean “one and only one” unless specifically so stated, but rather “one or more. ” Unless specifically stated otherwise, the term “some” refers to one or more. All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. No claim element is to be construed under the provisions of 35 U.S.C. §112 (f) unless the element is expressly recited using the phrase “means for” or, in the case of a method claim, the element is recited using the phrase “step for. ”

The various operations of methods described above may be performed by any suitable means capable of performing the corresponding functions. The means may include various hardware and/or software component (s) and/or module (s) , including, but not limited to a circuit, an application specific integrated circuit (ASIC) , or processor. Generally, where there are operations illustrated in figures, those operations may have corresponding counterpart means-plus-function components with similar numbering.

The various illustrative logical blocks, modules and circuits described in connection with the present disclosure may be implemented or performed with a general purpose processor, a digital signal processor (DSP) , an application specific integrated circuit (ASIC) , a field programmable gate array (FPGA) or other programmable logic device (PLD) , discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any commercially available processor, controller, microcontroller, or state machine. A processor may 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.

If implemented in hardware, an example hardware configuration may comprise a processing system in a wireless node. The processing system may be implemented with a bus architecture. The bus may include any number of interconnecting buses and bridges depending on the specific application of the processing system and the overall design constraints. The bus may link together various circuits including a processor, machine-readable media, and a bus interface. The bus interface may be used to connect a network adapter, among other things, to the processing system via the bus. The network adapter may be used to implement the signal processing functions of the PHY layer. In the case of a user terminal 120 (see FIG. 1) , a user interface (e.g., keypad, display, mouse, joystick, etc. ) may also be connected to the bus. The bus may also link various other circuits such as timing sources, peripherals, voltage regulators, power management circuits, and the like, which are well known in the art, and therefore, will not be described any further. The processor may be implemented with one or more general-purpose and/or special-purpose processors. Examples include microprocessors, microcontrollers, DSP processors, and other circuitry that can execute software. Those skilled in the art will recognize how best to implement the described functionality for the processing system depending on the particular application and the overall design constraints imposed on the overall system.

If implemented in software, the functions may be stored or transmitted over as one or more instructions or code on a computer readable medium. Software shall be construed broadly to mean instructions, data, or any combination thereof, whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. Computer-readable media include both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. The processor may be responsible for managing the bus and general processing, including the execution of software modules stored on the machine-readable storage media. A computer-readable storage medium may be coupled to a processor such that the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor. By way of example, the machine-readable media may include a transmission line, a carrier wave modulated by data, and/or a computer readable storage medium with instructions stored thereon separate from the wireless node, all of which may be accessed by the processor through the bus interface. Alternatively, or in addition, the machine-readable media, or any portion thereof, may be integrated into the processor, such as the case may be with cache and/or general register files. Examples of machine-readable storage media may include, by way of example, RAM (Random Access Memory) , flash memory, ROM (Read Only Memory) , PROM (Programmable Read-Only Memory) , EPROM (Erasable Programmable Read-Only Memory) , EEPROM (Electrically Erasable Programmable Read-Only Memory) , registers, magnetic disks, optical disks, hard drives, or any other suitable storage medium, or any combination thereof. The machine-readable media may be embodied in a computer-program product.

A software module may comprise a single instruction, or many instructions, and may be distributed over several different code segments, among different programs, and across multiple storage media. The computer-readable media may comprise a number of software modules. The software modules include instructions that, when executed by an apparatus such as a processor, cause the processing system to perform various functions. The software modules may include a transmission module and a receiving module. Each software module may reside in a single storage device or be distributed across multiple storage devices. By way of example, a software module may be loaded into RAM from a hard drive when a triggering event occurs. During execution of the software module, the processor may load some of the instructions into cache to increase access speed. One or more cache lines may then be loaded into a general register file for execution by the processor. When referring to the functionality of a software module below, it will be understood that such functionality is implemented by the processor when executing instructions from that software module.

Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL) , or wireless technologies such as infrared (IR) , radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. Disk and disc, as used herein, include compact disc (CD) , laser disc, optical disc, digital versatile disc (DVD) , floppy disk, and

disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Thus, in some aspects computer-readable media may comprise non-transitory computer-readable media (e.g., tangible media) . In addition, for other aspects computer-readable media may comprise transitory computer-readable media (e.g., a signal) . Combinations of the above should also be included within the scope of computer-readable media.

Thus, certain aspects may comprise a computer program product for performing the operations presented herein. For example, such a computer program product may comprise a computer-readable medium having instructions stored (and/or encoded) thereon, the instructions being executable by one or more processors to perform the operations described herein, for example, instructions for performing the operations described herein and illustrated in FIG. 5.

Further, it should be appreciated that modules and/or other appropriate means for performing the methods and techniques described herein can be downloaded and/or otherwise obtained by a user terminal and/or base station as applicable. For example, such a device can be coupled to a server to facilitate the transfer of means for performing the methods described herein. Alternatively, various methods described herein can be provided via storage means (e.g., RAM, ROM, a physical storage medium such as a compact disc (CD) or floppy disk, etc. ) , such that a user terminal and/or base station can obtain the various methods upon coupling or providing the storage means to the device. Moreover, any other suitable technique for providing the methods and techniques described herein to a device can be utilized.

It is to be understood that the claims are not limited to the precise configuration and components illustrated above. Various modifications, changes and variations may be made in the arrangement, operation and details of the methods and apparatus described above without departing from the scope of the claims.

Claims

A method for wireless communication, comprising:

determining whether a data transmission using channel repetition is successful, the data transmission being during at least one reference duration;

adjusting a size associated with a contention window (CW) based on the determination; and

communicating with a wireless node during the CW having the adjusted size.
The method of claim 1, wherein the at least one reference duration starts at a beginning of a channel occupancy time (COT) , the COT corresponding to a transmission time associated with the data transmission.
The method of claim 2, wherein the at least one reference duration ends at an earlier one of:

an end of a first slot during the reference duration that has at least one unicast data channel transmission; or

an end of a transmission burst during the reference duration having unicast data channel transmissions.
The method of claim 2, wherein the channel repetition comprises slot aggregation, and wherein the at least one reference duration ends at an earlier one of:

an end of a last slot during the reference duration that has a data channel transmission using the slot aggregation; or

an end of a data channel transmission burst using the slot aggregation during the reference duration.
The method of claim 1, wherein the data transmission is over a first transmit-receive point (TRP) and a second TRP, wherein the at least one reference duration comprises a first reference duration associated with the first TRP and a second reference duration associated with the second TRP.
The method of claim 5, wherein:

the data transmission using the channel repetition comprises a transmission of a first data channel during a first slot over the first TRP and a transmission of a second data channel during the first slot over the second TRP, the second data channel being a repetition of the first data channel; and

if the first data channel is punctured, the first reference duration ends at an end of a transmission of a third data channel during a second slot over the first TRP, the second slot being after the first slot.
The method of claim 6, wherein the second reference duration ends at an end of a transmission of the second data channel.
The method of claim 6, wherein the second reference duration ends at an end of a transmission of a fourth data channel during the second slot over the second TRP, the fourth data channel being a repetition of the third data channel.
The method of claim 1, wherein the data transmission comprises a downlink data channel transmission.
The method of claim 1, wherein the data transmission comprises an uplink data channel transmission.
The method of claim 1, further comprising:

sending the data transmission to the wireless node; and

receiving feedback indicating whether the data transmission is successfully decoded, the determination of whether the data transmission is successful being based on the feedback.
An apparatus for wireless communication, comprising:

a processing system configured to:

determine whether a data transmission using channel repetition is successful, the data transmission being during at least one reference duration;

adjust a size associated with a contention window (CW) based on the determination; and

a transceiver configured to communicate with a wireless node during the CW having the adjusted size.
An apparatus for wireless communication, comprising:

means for determining whether a data transmission using channel repetition is successful, the data transmission being during at least one reference duration;

means for adjusting a size associated with a contention window (CW) based on the determination; and

means for communicating with a wireless node during the CW having the adjusted size.
A computer-readable medium having instructions stored thereon to cause a processor to:

determine whether a data transmission using channel repetition is successful, the data transmission being during at least one reference duration;

adjust a size associated with a contention window (CW) based on the determination; and

communicate with a wireless node during the CW having the adjusted size.