JP7614173B2 - Techniques for determining conflict window updates. - Google Patents

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of Indian Application No. 201941031137, entitled "Techniques for Determining Contention Window Update," filed on August 1, 2019, and U.S. Patent Application No. 16/903,226, entitled "Techniques for Determining Contention Window Update," filed on June 16, 2020, which are expressly incorporated herein by reference in their entireties.

The present disclosure relates generally to communication systems, and more particularly to techniques for determining wireless communications including contention windows.

Wireless communication systems are widely deployed to provide various telecommunication services, such as telephone, video, data, messaging, and broadcast. A typical wireless communication system may utilize multiple access technologies capable of supporting communication with multiple users by sharing available system resources. Examples of such multiple access technologies include 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.

These multiple access technologies are being adopted in various telecommunications standards to provide common protocols that allow different wireless devices to communicate on a city, national, regional, or even global scale. An exemplary telecommunications standard is 5G New Radio (NR). 5G NR is part of the continuing mobile broadband evolution promulgated by the 3rd Generation Partnership Project (3GPP) to meet new requirements related to latency, reliability, security, scalability (e.g., with the Internet of Things (IoT)), and other requirements. 5G NR includes services associated with enhanced mobile broadband (eMBB), massive machine-type communications (mMTC), and ultra-reliable low-latency communications (URLLC).

Licensed Assisted Access (LAA) brings together licensed and unlicensed spectrum to generate higher capacity than can be provided by licensed spectrum alone. Increased network capacity is essential to handle the exponential growth of data traffic in cellular networks. LAA in 5G Unlicensed New Radio (NR-U) has new requirements and features.

The following presents a simplified summary of one or more embodiments in order to provide a basic understanding of such embodiments. This summary is not intended to be a comprehensive overview of all contemplated embodiments, nor is it intended to identify key or critical elements of all embodiments or to delineate the scope of any or all embodiments. Its sole purpose is to present some concepts of one or more embodiments in a simplified form as a prelude to the more detailed description that is presented later.

Techniques are provided for adjusting or updating the contention window (CW).

A user equipment (UE) may be configured to implement one or more techniques to determine a reference transmission for updating or adjusting a CW. The UE may employ such determination techniques to determine one or more uplink reference transmissions to use for adjusting or updating the UE's CW. The techniques for determining the reference transmission may include determining the reference transmission directly, or may include determining the reference transmission by first determining a reference duration and then determining the reference transmission based at least in part on the determined reference duration.

The base station may be configured to implement one or more techniques for determining a reference transmission for updating or adjusting the CW. Specifically, the base station may employ a reference transmission determination technique to determine one or more downlink reference transmissions for use in adjusting or updating the CW of the base station. The technique for determining the reference transmission may determine the reference transmission directly, or may determine the reference transmission by first determining a reference duration and then determining the reference transmission based at least in part on the determined reference duration.

Once the reference signal is determined, the transmitting node may monitor the success or failure of the transmitted reference signal (e.g., an ACK or NACK transmitted by the receiving node). The transmitting node may then use the success or failure of the receiving node to receive the transmitted reference signal and selectively adjust the transmitting node's CW.

In one aspect of the present disclosure, a method, computer-readable medium, and apparatus for wireless communications are provided. The apparatus may determine a reference duration of a channel occupancy time (COT), the reference duration being based at least in part on a subcarrier spacing (SCS) and based on receipt of a physical downlink shared channel (PDSCH) transmission. The apparatus may update a CW based at least in part on receipt of the PDSCH transmission during the reference duration.

In another aspect of the present disclosure, a method, a computer-readable medium, and an apparatus for wireless communication in a base station are provided. The base station may determine a reference duration of the COT, the reference duration being based at least in part on the SCS. The base station may further determine at least one reference physical downlink control channel (PDCCH) transmission to be transmitted during the reference duration. The base station may further update the CW based at least in part on an uplink transmission having the at least one reference PDCCH transmission transmitted during the reference duration.

In another aspect of the present disclosure, a method, a computer-readable medium, and an apparatus are provided for wireless communication in a base station. The base station may determine a reference duration of the COT. The base station may further determine whether to use a reference PDSCH transmission or a reference physical uplink shared channel (PUSCH) transmission to update the CW. The base station may further update the CW based on the PDSCH or the reference PUSCH transmission and the reference duration.

In another aspect of the disclosure, a method, computer-readable medium, and apparatus are provided for wireless communication in a UE. The UE may determine a reference duration of the COT based on a first slot of a proximate set of uplink shared channel transmissions during the COT. The UE may update a CW based at least in part on the uplink shared channel transmissions during the reference duration. The uplink shared channel transmissions may include, for example, discontinuous uplink shared channel transmissions. The CW may further be updated based on, for example, downlink transmissions during the COT.

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 annexed 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 the various aspects may be employed and the description is intended to include all such aspects and their equivalents.

FIG. 1 illustrates an example of a wireless communication system and access network. A figure showing an example of a first 5G/NR frame. FIG. 1 illustrates an example of a DL channel in a 5G/NR subframe. A figure showing an example of a second 5G/NR frame. FIG. 1 illustrates an example of a UL channel in a 5G/NR subframe. FIG. 1 illustrates an example of a base station and user equipment (UE) in an access network. FIG. 2 illustrates a call flow using a contention window (CW) size adjustment technique according to some implementations. A diagram showing various techniques for determining a reference duration (RD), a reference signal, and a CW size according to some implementations. 1 illustrates a technique for determining a reference duration within a slot unit, according to an example. FIG. 13 illustrates a technique for determining a reference duration within symbol unit scheduling, according to another example. 1 illustrates a technique for determining a reference signal based at least in part on a reference duration and a starting point of the reference signal, according to an example. FIG. 11 illustrates a technique for determining a reference signal based at least in part on a reference duration and a tail point of the reference signal, according to another example. FIG. 11 illustrates a technique for determining a reference signal based at least in part on a reference duration, a starting point of the reference signal, and an ending point of the reference signal, according to another example. 1 illustrates a technique for determining a reference duration when a PDSCH is punctured, according to an example. 13 illustrates a technique for determining a reference duration when a PDSCH is punctured, according to another example. 1 illustrates a technique for determining a reference duration when a PDSCH is subband punctured, according to an example. 13 illustrates a technique for determining a reference duration when a PDSCH is subband punctured, according to another example. 1 illustrates one or more reference signals determined directly from a predetermined time or a predetermined number of symbols within a first slot, according to an example. FIG. 1 illustrates a UE-initiated COT with Category 4 Listen-Before-Talk (LBT), in which a UE-side CW size adjustment technique may be applied according to an example. 1 is a flowchart of a method of wireless communication according to a first example. 11 is a flowchart of a method of wireless communication according to a second example. 11 is a flowchart of a method of wireless communication according to a third example. 11 is a flowchart of a method of wireless communication according to a fourth example. FIG. 2 is a data flow diagram illustrating the data flow between different means/components in an exemplary apparatus. FIG. 1 illustrates an example of a hardware implementation for an apparatus employing a processing system. FIG. 2 is a data flow diagram illustrating the data flow between different means/components in an exemplary apparatus. FIG. 1 illustrates an example of a hardware implementation for an apparatus employing a processing system.

The detailed description set forth below with respect to the accompanying drawings is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of the various concepts. However, it will be apparent to one skilled in the art that these concepts may be practiced without these specific details. In some instances, well-known structures and components are shown in block diagram form to avoid obscuring such concepts.

Below, several aspects of a telecommunications system are presented with reference to various apparatus and methods. These apparatus and methods are described in the detailed description that follows and illustrated in the accompanying drawings by various blocks, components, circuits, processes, algorithms, etc. (collectively referred to as "elements"). These elements may be implemented using electronic hardware, computer software, or any combination thereof. Whether such elements are implemented as hardware or software depends on the particular application and design constraints imposed on the overall system.

By way of example, an element or any portion of an element or any combination of elements may be implemented as a "processing system" including one or more processors. Examples of processors include microprocessors, microcontrollers, graphics processing units (GPUs), central processing units (CPUs), application processors, digital signal processors (DSPs), reduced instruction set computing (RISC) processors, systems on chips (SoCs), baseband processors, field programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gate logic, discrete hardware circuits, and other suitable hardware configured to perform various functions described throughout this disclosure. One or more processors in a processing system may execute software. Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software components, applications, software applications, software packages, routines, subroutines, objects, executable files, threads of execution, procedures, functions, and the like, whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise.

Thus, in one or more examples, the functions described may be implemented in hardware, software, or any combination thereof. If implemented in software, the functions may be stored or encoded as one or more instructions or code on a computer-readable medium. Computer-readable media includes computer storage media. A storage medium may be any available medium that can be accessed by a computer. By way of example and not limitation, such computer-readable media may comprise random access memory (RAM), read-only memory (ROM), electrically erasable programmable ROM (EEPROM), optical disk storage, magnetic disk storage, other magnetic storage devices, combinations of the above types of computer-readable media, or any other medium that can be used to store computer-executable code in the form of instructions or data structures that can be accessed by a computer.

Figure 1 illustrates an example of a wireless communication system and access network 100. The wireless communication system (also called a wireless wide area network (WWAN)) includes a base station 102, a UE 104, an evolved packet core (EPC) 160, and another core network 190 (e.g., 5G core (5GC)). The base station 102 may include a macro cell (high power cellular base station) and/or a small cell (low power cellular base station). The macro cell includes a base station. The small cell includes a femto cell, a pico cell, and a micro cell.

A base station 102 configured for 4G LTE (collectively referred to as Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN)) may interface with the EPC 160 through a backhaul link 132 (e.g., an S1 interface). A base station 102 configured for 5G NR (collectively referred to as Next Generation RAN (NG-RAN)) may interface with the core network 190 through a backhaul link 184. In addition to other functions, the base station 102 may perform one or more of the following functions: forwarding of user data, encryption and decryption of radio channels, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity), inter-cell interference coordination, connection setup and release, load balancing, distribution for non-access stratum (NAS) messages, NAS node selection, synchronization, radio access network (RAN) sharing, multimedia broadcast multicast service (MBMS), subscriber and equipment tracking, RAN information management (RIM), paging, positioning, and delivery of alert messages. The base stations 102 may communicate with each other directly or indirectly (e.g., through the EPC 160 or the core network 190) via backhaul links 134 (e.g., X2 interfaces). The backhaul links 134 may be wired or wireless.

The base stations 102 may wirelessly communicate with the UE 104. Each of the base stations 102 may provide communication coverage in a respective geographic coverage area 110. There may be overlapping geographic coverage areas 110. For example, a small cell 102' may have a coverage area 110' that overlaps with the coverage area 110 of one or more macro base stations 102. A network including both small cells and macro cells may be referred to as a heterogeneous network. A heterogeneous network may also include a Home evolved Node B (eNB) (HeNB), which may serve a restricted group called a Closed Subscriber Group (CSG). A communication link 120 between the base station 102 and the UE 104 may include an uplink (UL) (also referred to as a reverse link) transmission from the UE 104 to the base station 102, and/or a downlink (DL) (also referred to as a forward link) transmission from the base station 102 to the UE 104. The communication link 120 may use multiple-input multiple-output (MIMO) antenna techniques, including spatial multiplexing, beamforming, and/or transmit diversity. The communication link may be over one or more carriers. The base station 102/UE 104 may use spectrum with bandwidth up to Y MHz (e.g., 5, 10, 15, 20, 100, 400 MHz, etc.) per carrier, allocated in carrier aggregation with up to a total of Yx MHz (x component carriers) used for transmission in each direction. The carriers may or may not be adjacent to each other. The carrier allocation may be asymmetric with respect to DL and UL (e.g., more or fewer carriers may be allocated for DL than UL). The component carriers may include a primary component carrier and one or more secondary component carriers. The primary component carrier may be referred to as a primary cell (PCell) and the secondary component carrier may be referred to as a secondary cell (SCell).

Several UEs 104 may communicate with each other using device-to-device (D2D) communication links 158. The D2D communication links 158 may use DL/UL WWAN spectrum. The D2D communication links 158 may use one or more sidelink channels, such as a physical sidelink broadcast channel (PSBCH), a physical sidelink discovery channel (PSDCH), a physical sidelink shared channel (PSSCH), and a physical sidelink control channel (PSCCH). The D2D communication may be through various wireless D2D communication systems, such as, for example, FlashLinQ, WiMedia, Bluetooth, ZigBee, Wi-Fi based on IEEE 802.11 standards, LTE, or NR.

The wireless communication system may further include a Wi-Fi access point (AP) 150 in communication with a Wi-Fi station (STA) 152 via a communication link 154 in the 5 GHz unlicensed frequency spectrum. When communicating in the unlicensed frequency spectrum, the STA 152/AP 150 may perform a clear channel assessment (CCA) prior to communicating to determine if a channel is available.

The small cell 102' may operate in licensed and/or unlicensed frequency spectrum. When operating in the unlicensed frequency spectrum, the small cell 102' may employ NR and use the same 5 GHz unlicensed frequency spectrum used by the Wi-Fi AP 150. A small cell 102' utilizing NR in the unlicensed frequency spectrum may provide increased coverage to and/or increase the capacity of the access network.

The base station 102, whether a small cell 102' or a large cell (e.g., a macro base station), may include an eNB, a gNodeB (gNB), or another type of base station. Some base stations, such as the gNB 180, may communicate with the UE 104 and operate in the traditional sub-6 GHz spectrum, millimeter wave (mmW) frequencies, and/or sub-mmW frequencies. When the gNB 180 operates in mmW or sub-mmW frequencies, the gNB 180 may be referred to as a mmW base station. Extremely high frequency (EHF) is a part of RF in the electromagnetic spectrum. EHF has a range of 30 GHz to 300 GHz and a wavelength between 1 millimeter and 10 millimeters. Radio waves in that band may be referred to as millimeter waves. Sub-mmW may extend downward to frequencies of 3 GHz with a wavelength of 100 millimeters. The very high frequency (SHF) band extends between 3 GHz and 30 GHz and is also referred to as centimeter wave. Communications using mmW/sub-mmW radio frequency bands (e.g., 3 GHz to 300 GHz) have very high path losses and short distances. The mmW base station 180 may utilize beamforming 182 with the UE 104 to compensate for the very high path losses and short distances.

The base station 180 may transmit a beamformed signal to the UE 104 in one or more transmit directions 182'. The UE 104 may receive a beamformed signal from the base station 180 in one or more receive directions 182''. The UE 104 may also transmit a beamformed signal to the base station 180 in one or more transmit directions. The base station 180 may receive a beamformed signal from the UE 104 in one or more receive directions. The base station 180/UE 104 may perform beam training to determine the best receive direction and transmit direction for each of the base station 180/UE 104. The transmit direction and receive direction for the base station 180 may be the same or different. The transmit direction and receive direction for the UE 104 may be the same or different.

The EPC 160 may include a Mobility Management Entity (MME) 162, other MMEs 164, a Serving Gateway 166, an MBMS Gateway 168, a Broadcast Multicast Service Center (BM-SC) 170, and a Packet Data Network (PDN) Gateway 172. The MME 162 may be in communication with a Home Subscriber Server (HSS) 174. The MME 162 is a control node that handles signaling between the UE 104 and the EPC 160. In general, the MME 162 handles bearer and connection management. All user Internet Protocol (IP) packets are forwarded through the Serving Gateway 166, which is itself connected to the PDN Gateway 172. The PDN Gateway 172 provides UE IP address allocation as well as other functions. The PDN Gateway 172 and the BM-SC 170 are connected to the IP Services 176. The IP services 176 may include Internet, intranet, IP Multimedia Subsystem (IMS), PS streaming services, and/or other IP services. The BM-SC 170 may provide functionality for MBMS user service provisioning and delivery. The BM-SC 170 may act as an entry point for content provider MBMS transmissions, may be used to authorize and initiate MBMS bearer services in the Public Land Mobile Network (PLMN), and may be used to schedule MBMS transmissions. The MBMS Gateway 168 may be used to deliver MBMS traffic to base stations 102 that belong to a Multicast Broadcast Single Frequency Network (MBSFN) area that broadcasts a particular service, and may be responsible for session management (start/stop) and collecting eMBMS-related charging information.

The core network 190 may include an access and mobility management function (AMF) 192, other AMFs 193, a session management function (SMF) 194, and a user plane function (UPF) 195. The AMF 192 may be in communication with an integrated data management (UDM) 196. The AMF 192 is a control node that handles signaling between the UE 104 and the core network 190. In general, the AMF 192 provides QoS flow and session management. All user Internet Protocol (IP) packets are forwarded through the UPF 195. The UPF 195 provides IP address allocation for the UE as well as other functions. The UPF 195 is connected to IP services 197. The IP services 197 may include the Internet, intranet, IP multimedia subsystem (IMS), PS streaming services, and/or other IP services.

A base station may include and/or be referred to as a gNB, Node B, evolved Node B (eNB), access point, base transceiver station, radio base station, radio transceiver, transceiver function, basic service set (BSS), enhanced service set (ESS), transmit/receive point (TRP), or some other suitable terminology. The base station 102 provides an access point to the EPC 160 or core network 190 for the UE 104. Examples of the UE 104 include a mobile phone, a smartphone, a session initiation protocol (SIP) phone, a laptop, a personal digital assistant (PDA), a satellite radio, a global positioning system, a multimedia device, a video device, a digital audio player (e.g., MP3 player), a camera, a game console, a tablet, a smart device, a wearable device, a vehicle, an electric meter, a gas pump, a large or small cooking appliance, a health management device, an implant, a sensor/actuator, a display, or any other similarly functional device. Some of the UEs 104 may be referred to as IoT devices (e.g., parking meters, gas pumps, toasters, vehicles, heart monitors, etc.). The UEs 104 may also be referred to as stations, mobile stations, subscriber stations, mobile units, subscriber units, wireless units, remote units, mobile devices, wireless devices, wireless communication devices, remote devices, mobile subscriber stations, access terminals, mobile terminals, wireless terminals, remote terminals, handsets, user agents, mobile clients, clients, or some other suitable terminology.

Referring back to FIG. 1, in some aspects, the UE 104 may include a contention window component 199 configured to implement one or more techniques for determining a CW update/adjustment, which may include determining a reference transmission for determining a CW update. Referring back to FIG. 1, in other aspects, the base station 102/180 may include a contention window component 198 configured to determine a CW update or adjustment, for example, the contention window component 198 may include determining a reference transmission for determining a CW update.

These reference transmission decision techniques, which may be employed by the contention window components 198, 199 and described in more detail below, enable a decision of which transmission signal to use to make a CW update or adjustment. These techniques may be particularly important to support CW adjustments and updates in either the UE 104 or the base station 102/180. Although the following description focuses on 5G/NR, the technique concepts described herein may be applicable to other similar fields, such as LTE, LTE-A, and other wireless technologies, where the UE 104 or base station 102 needs to decide on a CW adjustment.

Figure 2A is a diagram 200 illustrating an example of a first subframe in a 5G/NR frame structure. Figure 2B is a diagram 230 illustrating an example of a DL channel in a 5G/NR subframe. Figure 2C is a diagram 250 illustrating an example of a second subframe in a 5G/NR frame structure. Figure 2D is a diagram 280 illustrating an example of a UL channel in a 5G/NR subframe. The 5G/NR frame structure may be FDD, where for a particular set of subcarriers (carrier system bandwidth), subframes within the set of subcarriers are dedicated to either DL or UL, or TDD, where for a particular set of subcarriers (carrier system bandwidth), subframes within the set of subcarriers are dedicated to both DL and UL. In the example given by Figures 2A, 2C, the 5G/NR frame structure is assumed to be TDD, subframe 4 is configured with slot format 28 (mostly with DL), where D is DL, U is UL, and X is flexible for use between DL/UL, and subframe 3 is configured with slot format 34 (mostly with UL). Subframes 3, 4 are shown with slot formats 34, 28, respectively, but any particular subframe may be configured with any of the various available slot formats 0-61. Slot formats 0, 1 are all DL, UL, respectively. The other slot formats 2-61 include a mix of DL, UL, and flexible symbols. The UE is configured with the slot format through a received slot format indicator (SFI) (either dynamically through DL control information (DCI) or semi-statically/statically through radio resource control (RRC) signaling). Please note that the following description also applies to the 5G/NR frame structure, which is TDD.

Other wireless communication technologies may have different frame structures and/or different channels. A frame (10 ms) may be divided into 10 equally sized subframes (1 ms). Each subframe may include one or more time slots. A subframe may also include a minislot, which may include 7, 4, or 2 symbols. Each slot may include 7 or 14 symbols depending on the slot configuration. In slot configuration 0, each slot may include 14 symbols, and in slot configuration 1, each slot may include 7 symbols. Symbols on the DL may be Cyclic Prefix (CP) OFDM (CP-OFDM) symbols. Symbols on the UL may be CP-OFDM symbols (for high throughput scenarios) or Discrete Fourier Transform (DFT) Spread OFDM (DFT-s-OFDM) symbols (also called Single Carrier Frequency Division Multiple Access (SC-FDMA) symbols) (limited to a single stream transmission for power-limited scenarios). The number of slots in a subframe is based on the slot configuration and numerology. In slot configuration 0, the different numerologies μ 0-5 allow 1, 2, 4, 8, 16, and 32 slots per subframe, respectively. In slot configuration 1, the different numerologies 0-2 allow 2, 4, and 8 slots per subframe, respectively. Thus, for slot configuration 0 and numerology μ, there are 14 symbols/slot and 2μ slots/subframe. The subcarrier spacing and the symbol length/duration depend on the numerology. The subcarrier spacing may be equal to ^2μ *15kHz, where μ is the numerology 0-5. Thus, numerology μ=0 has a subcarrier spacing of 15kHz and numerology μ=5 has a subcarrier spacing of 480kHz. The symbol length/duration is inversely related to the subcarrier spacing. Figures 2A-2D give an example of slot configuration 0 with 14 symbols per slot and numerology μ=0 with 1 slot per subframe. The subcarrier spacing is 15 kHz and the symbol duration is approximately 66.7 μs.

The resource grid may be used to represent the frame structure. Each timeslot contains a resource block (RB), also called a physical RB (PRB), that spans 12 consecutive subcarriers. The resource grid is divided into multiple resource elements (REs). The number of bits carried by each RE depends on the modulation scheme.

As shown in FIG. 2A, some of the REs carry reference (pilot) signals (RS) for the UE. The RS may include demodulation RS (DM-RS) (denoted as Rx for one particular configuration, where 100x is the port number, but other DM-RS configurations are possible) and channel state information reference signals (CSI-RS) for channel estimation at the UE. The RS may also include beam measurement RS (BRS), beam improvement RS (BRRS), and phase tracking RS (PT-RS).

FIG. 2B illustrates an example of various DL channels within a subframe of a frame. The physical downlink control channel (PDCCH) carries DCI within one or more control channel elements (CCEs), each CCE including nine RE groups (REGs), each REG including four consecutive REs in an OFDM symbol. A primary synchronization signal (PSS) may be within symbol 2 of a particular subframe of the frame. The PSS is used by the UE 104 to determine subframe/symbol timing and physical layer identity. A secondary synchronization signal (SSS) may be within symbol 4 of a particular subframe of the frame. The SSS is used by the UE to determine a physical layer cell identity group number and radio frame timing. Based on the physical layer identity and the physical layer cell identity group number, the UE can determine a physical cell identifier (PCI). Based on the PCI, the UE can determine the location of the DM-RS described above. The Physical Broadcast Channel (PBCH), which carries the Master Information Block (MIB), may be logically grouped with the PSS and SSS to form the Synchronization Signal (SS)/PBCH block. The MIB provides the number of RBs in the system bandwidth and the System Frame Number (SFN). The Physical Downlink Shared Channel (PDSCH) carries user data and broadcast system information not transmitted over the PBCH, such as the System Information Block (SIB), and paging messages.

As shown in FIG. 2C, some of the REs carry DM-RS (denoted as R for one particular configuration, but other DM-RS configurations are possible) for channel estimation at the base station. The UE may transmit DM-RS for the physical uplink control channel (PUCCH) and DM-RS for the physical uplink shared channel (PUSCH). The PUSCH DM-RS may be transmitted in the first one or two symbols of the PUSCH. The PUCCH DM-RS may be transmitted in different configurations depending on whether a short or long PUCCH is transmitted and depending on the particular PUCCH format used. Although not shown, the UE may transmit a sounding reference signal (SRS). The SRS may be used by the base station for channel quality estimation to enable frequency-dependent scheduling on the UL.

Figure 2D illustrates an example of various UL channels within a subframe of a frame. The PUCCH, in one configuration, may be arranged as shown. The PUCCH carries uplink control information (UCI) such as scheduling requests, channel quality indicators (CQI), precoding matrix indicators (PMI), rank indicators (RI), and HARQ ACK/NACK feedback. The PUSCH carries data and may be further used to carry buffer status reports (BSR), power headroom reports (PHR), and/or UCI.

3 is a block diagram of a base station 310 in communication with a UE 350 in an access network. In the DL, IP packets from the EPC 160 may be provided to a controller/processor 375. The controller/processor 375 performs Layer 3 and Layer 2 functions. Layer 3 includes the Radio Resource Control (RRC) layer, and Layer 2 includes the Service Data Adaptation Protocol (SDAP) layer, the Packet Data Convergence Protocol (PDCP) layer, the Radio Link Control (RLC) layer, and the Medium Access Control (MAC) layer. The controller/processor 375 controls RRC layer functions associated with broadcasting of system information (e.g., MIBs, 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 functions associated with header compression/decompression, security (encryption, decryption, integrity protection, integrity verification), and handover support functions; RLC layer functions associated with forwarding of upper layer packet data units (PDUs), error correction via ARQ, concatenation, segmentation, and reassembly of RLC service data units (SDUs), re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and mapping between logical channels and transport channels, multiplexing of MAC SDUs onto transport blocks (TBs), MAC SDUs from TBs, and MAC SDUs from TBs. It provides MAC layer functions associated with demultiplexing of SDUs, scheduling information reporting, error correction via HARQ, priority handling, and logical channel prioritization.

The transmit (TX) processor 316 and receive (RX) processor 370 implement Layer 1 functionality associated with various signal processing functions. Layer 1, including the physical (PHY) layer, may include error detection on the transport channel, forward error correction (FEC) coding/decoding of the transport channel, interleaving, rate matching, mapping onto the physical channel, modulation/demodulation of the physical channel, and MIMO antenna processing. The TX processor 316 handles mapping to signal constellations based on various modulation schemes (e.g., binary phase shift keying (BPSK), quadrature phase shift keying (QPSK), M-phase shift keying (M-PSK), M-ary quadrature amplitude modulation (M-QAM)). The coded and modulated symbols may then be split into parallel streams. Each stream may then be mapped to OFDM subcarriers, multiplexed with a reference signal (e.g., pilot) in the time and/or frequency domain, and then combined together using an inverse fast Fourier transform (IFFT) to generate a physical channel carrying a time-domain OFDM symbol stream. The OFDM streams are spatially precoded to generate multiple spatial streams. Channel estimates from a channel estimator 374 may be used to determine the coding and modulation scheme and for spatial processing. The channel estimates may be derived from a reference signal and/or channel condition feedback transmitted by the UE 350. Each spatial stream may then be provided to a different antenna 320 via a separate transmitter 318TX. Each transmitter 318TX may modulate an RF carrier with the respective spatial stream for transmission.

At the UE 350, each receiver 354RX receives a signal through its respective antenna 352. Each receiver 354RX recovers the information modulated onto the RF carrier and provides the information to a receive (RX) processor 356. The TX processor 368 and the RX processor 356 implement Layer 1 functions related to various signal processing functions. The RX processor 356 may perform spatial processing on the information to recover any spatial streams directed to the UE 350. Multiple spatial streams may be combined by the RX processor 356 into a single OFDM symbol stream if they are destined for the UE 350. The RX processor 356 then converts the OFDM symbol stream from the time domain to the frequency domain using a Fast Fourier Transform (FFT). The frequency domain signal comprises a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols on each subcarrier, as well as the reference signal, are recovered and demodulated by determining the most likely signal constellation point transmitted by the base station 310. These soft decisions may be based on channel estimates calculated by a channel estimator 358. The soft decisions are then decoded and deinterleaved to recover the data and control signals originally transmitted by the base station 310 on the physical channel. The data and control signals are then provided to a controller/processor 359, which performs Layer 3 and Layer 2 functions.

The controller/processor 359 can be associated with a memory 360 that stores program codes and data. The memory 360 may be referred to as a computer-readable medium. In the UL, the controller/processor 359 performs demultiplexing between transport and logical channels, packet reassembly, decryption, header decompression, and control signal processing to recover IP packets from the EPC 160. The controller/processor 359 is also responsible for error detection using an ACK and/or NACK protocol to support HARQ operations.

Similar to the functionality described with respect to DL transmission by base station 310, controller/processor 359 provides RRC layer functionality associated with system information (e.g., MIB, SIB) collection, RRC connection, and measurement reporting; PDCP layer functionality associated with header compression/decompression and security (encryption, decryption, integrity protection, integrity verification); RLC layer functionality associated with forwarding of higher layer PDUs, error correction via ARQ, concatenation, segmentation, and reassembly of RLC SDUs, resegmentation 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 TBs, demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction via HARQ, priority handling, and logical channel prioritization.

Channel estimates derived by the channel estimator 358 from a reference signal or feedback transmitted by the base station 310 may be used by the TX processor 368 to select an appropriate coding and modulation scheme as well as to facilitate spatial processing. The spatial streams generated by the TX processor 368 may be provided to different antennas 352 via separate transmitters 354TX. Each transmitter 354TX may modulate an RF carrier with a respective spatial stream for transmission.

The UL transmissions are processed in the base station 310 in a manner similar to that described for the receiver functions in the UE 350. Each receiver 318RX receives the signal through its respective antenna 320. Each receiver 318RX recovers the information modulated onto the RF carrier and provides the information to the RX processor 370.

The controller/processor 375 may be associated with a memory 376 that stores program codes and data. The memory 376 may be referred to as a computer-readable medium. In the UL, the controller/processor 375 performs demultiplexing between transport and logical channels, packet reassembly, decryption, header decompression, and control signal processing to recover IP packets from the UE 350. The IP packets from the controller/processor 375 may be provided to the EPC 160. The controller/processor 375 is also responsible for error detection to support HARQ operations using an ACK and/or NACK protocol.

At least one of the TX processor 316, the RX processor 370, and the controller/processor 375 may be configured to perform aspects related to techniques for determining a reference signal for a CW update and may include the contention window component 198 of FIG. 1. Similarly, at least one of the TX processor 368, the RX processor 356, and the controller/processor 359 may be configured to perform aspects related to techniques for determining a reference signal for a CW update and may include the contention window component 199 of FIG. 1.

Spectrum sharing provides access to shared and unlicensed spectrum that offers higher capacity, higher spectrum utilization, and the benefits of new deployments. These deployments may include licensed spectrum aggregation enabling enhanced mobile broadband with higher speeds and better user experience, or enhanced local broadband enabling private networks providing enterprise services such as industrial IoT applications, or hosted networks such as for sports and entertainment venues. For example, LAA combines the use of licensed and unlicensed spectrum to generate higher capacity than could be provided by licensed spectrum alone.

Before gaining access to and communicating over a contention-based shared radio frequency spectrum band, a base station or UE may perform a Listen-Before-Talk (LBT) procedure to compete for access to the shared radio frequency spectrum band. The LBT procedure may include performing a CCA procedure to determine whether a channel in the contention-based shared radio frequency spectrum band is available. When a channel in the contention-based shared radio frequency spectrum band is determined to be available, the wireless device may transmit a channel reservation signal, such as a Channel Usage Beacon Signal (CUBS), to reserve the channel. The CCA procedure used by the wireless device to check before using a particular channel may be based on energy detection. The wireless device may perform energy detection to detect the presence or absence of other signals on the channel to determine whether the channel is occupied or vacant. The duration between performing CCA may be based on a CW size, a random backoff, an energy detection threshold, etc. For LAA, the wireless device may employ an LBT procedure. LBT, which may also be known as Listen-Before-Transmit, is a technique used by a transmitter to first sense the radio environment before starting transmission. A wireless device may initiate an LBT procedure, such as a Category 4 LBT procedure, using a contention window (CW). The CW may be a positive integer indicating the length of time during which the UE senses the radio environment. A longer CW may result in a higher backoff by the wireless device. The CW may be adjusted based on network conditions. When the network is congested, the transmitting device receives a NACK in response to a transmission, or no acknowledgement at all. In response to receiving negative feedback or failing to receive feedback, the device may increase the CW, for example, by doubling the CW size, multiplying by a factor, or adding an offset. When the network is less congested, as indicated by the transmitting device receiving an ACK, the device may decrease the CW (e.g., reset it to a minimum value).

In this manner, some aspects of updating the CW of the transmitting device may be based on the success or failure of a reference transmission received by the receiving device. The transmitting device may identify the reference transmission as a transmitted signal transmitted during a reference slot of the COT. For example, the reference slot may be the first valid slot of the COT. Since the Wi-Fi device may transmit a request to send (RTS)/clear to send (CTS) and a stop, utilizing an earlier portion of the COT to determine the CW update may provide a more accurate LBT procedure. For example, the reference slot may be the first slot in the COT, or the first partial slot (in the case of a punctured transmission) and subsequent slots in the COT. The CW may be adjusted based at least in part on the first slot in the COT, or the partial slot and subsequent slots in the COT for a punctured transmission.

However, slot sizes may differ based on different subcarrier spacings (SCS). For a 15 kHz SCS, a slot has a duration of 1 ms. For a 30 kHz SCS, a slot has a duration of 0.5 ms. For example, in NR-U communications, different SCSs may be used for communications. Also, for a given SCS, the duration of downlink transmissions may differ (e.g., the duration of PDSCH transmissions may differ, with some PDSCHs spanning only a few symbols of a slot). Some techniques described below take these considerations into account in determining the RD and reference transmissions to use for CW adjustment.

Furthermore, even when the PDSCH transmission is punctured, code block group (CBG)-based feedback may still be available. Some techniques described below utilize CBG-based feedback such that the reference duration may include durations less than a full slot followed by a partial slot.

CW size adjustment technique for UE and base station

FIG. 4 illustrates a call flow 400 using CW size adjustment techniques (e.g., 412, 418, 422, and 428) according to some implementations. The UE 402 may employ the CW size adjustment techniques (e.g., 412 and 418) to adjust or update its CW size or value. At 410, the UE 402 transmits one or more uplink transmissions to the base station 404 at a transmission opportunity (TxOp). The uplink transmission may be, for example, a PUCCH or PUSCH transmission. At block 412, the UE 402 determines at least one uplink reference transmission, either directly or based on the determined RD. At block 418, the UE 402 updates or adjusts its CW based on one or more ACK/NACKs of the reference transmissions transmitted by the base station 404 and received by the UE 402 at 414.

Similarly, the base station 404 may employ CW size adjustment techniques (e.g., 422 and 428) to adjust or update its CW size or value. At 420, the base station 404 may transmit one or more downlink transmissions to the UE 402 in a TxOp. The downlink transmission may be, for example, a PDCCH or PDSCH transmission. At block 422, the base station 404 determines at least one downlink reference transmission, either directly or based on the determined RD. At block 428, the base station 404 updates or adjusts its CW size based on one or more ACK/NACK feedbacks of the reference transmissions transmitted by the UE 402 and received by the base station 404 at 424.

FIG. 5 illustrates various techniques 500 for determining RD, reference transmission, and CW size according to some implementations. The RD determination component 504 may include an SCS-dependent RD generator 508 that generates an RD 506 that depends on the SCS. The SCS-dependent RD generator 508 may also include a slot-based RD determination technique 514 and a symbol-based RD determination technique 515. The slot-based RD determination technique 514 is described in more detail below with reference to FIG. 6A, and the symbol-based RD determination technique 515 is described in more detail below with reference to FIG. 6B.

The RD determination component 504 may also include a puncturing technique 516 for selectively extending the RD when one or more transmissions are punctured, and a sub-band puncturing technique 518 for selectively extending the RD when one or more transmissions are punctured in time and frequency. The puncturing technique 516 is described in more detail below with reference to Figures 8A and 8B. The sub-band puncturing technique 518 is described in more detail below with reference to Figures 9A and 9B.

Slot-based reference duration

With reference to FIG. 6A, one or more slot-based RD techniques 514 may be utilized to generate an RD 506 based on a number of slots (e.g., an RD having a duration in units of slots). In one example, the RD 506 may be based on a minimum supported SCS. As an example, the RD may be predefined based on a minimum supported SCS (e.g., an RD of 1 ms may be used if the minimum supported SCS is 15 kHz). The RD may be based on a minimum SCS supported by the transmitting device. For example, if a base station supports a minimum SCS of 15 kHz, the base station may use an RD of 1 ms. If a base station supports a minimum SCS of 30 kHz, the base station may use an RD of 0.5 ms. If a base station supports a minimum SCS of 60 kHz, the base station may use an RD of 0.25 ms. If a base station supports a minimum SCS of 120 kHz, the base station may use an RD of 0.125 ms. If a base station supports a minimum SCS of 240 kHz, the base station may use an RD of 0.0625 ms. FIG. 6A illustrates an example slot size 604 and two different RDs 610 and 614 based on different reference SCS sizes. FIG. 6B also illustrates an example symbol size 644 and the size of an RD 640 with a duration based on a reference SCS. In FIG. 6A, the duration of the RD is based on a slot size, e.g., a number of slots. In FIG. 6B, the duration of the RD has a symbol-based duration, e.g., one or more symbols of length. Thus, in FIG. 6A, the RD may have a size of a particular number of slots, and in FIG. 6B, the RD may have a size of a particular number of symbols. Although the aspects are described using a base station example, this is merely an illustration of the concept. The aspects may be applied by a UE as well.

In a second example, RD 506 may be determined as a function of the minimum SCS actually used at the beginning of the COT (e.g., 510). For example, if the base station uses a 15 kHz SCS for transmission at the beginning of the COT, the base station may use an RD of 1 ms. If instead the base station uses a 30 kHz SCS, the base station may use an RD 506 of 0.5 ms. Alternatively, RD may be based on the maximum SCS used by the transmitting device at the beginning of the COT (e.g., at 511). For example, if the base station uses a maximum SCS of 30 kHz, the base station may use an RD of 0.5 ms, and so on.

The RD may be different for different SCSs, such that for CW adjustment, the PDSCH of a particular SCS is considered within the duration corresponding to that SCS without considering the PDSCH of the different SCS. The RD determination component 504 may use any of a variety of techniques 512 to determine different reference durations for each SCS. For example, the technique 512 may be utilized to determine a separate SCS-specific RD, such that the PDSCH of a particular SCS may be included within the duration corresponding to that SCS. For example, all of the 15 kHz PDSCHs transmitted during the first 1 ms of the COT and all of the 30 kHz PDSCHs transmitted during the first 0.5 ms of the COT may be considered for CW updating.

In one example, RD may be based on a maximum RD value determined by using any of the techniques described above. In another example, a lower limit (e.g., a minimum RD value) may be applied to the result of the maximum function, such that RD may not fall below a predetermined value. For example, the lower limit may be a duration of 0.5 ms or some other predetermined value.

Symbol-based RD

Although the aspects are described using the example of a base station, this is merely an illustration of the concept. The aspects may be applied by a UE as well. When the transmitted PDSCH in the first slot does not occupy all symbols, the base station may determine the RD based on a partial slot, e.g., on a symbol basis. Such scheduling is sometimes referred to herein as sub-slot scheduling. For example, the RD may extend from the beginning of the first slot to the symbol of the earliest ending PDSCH. For example, considering three PDSCHs, the first PDSCH is from S1 to S3 (S=symbol), another PDSCH is from S4 to S13, and another PDSCH is from S1 to S13. In this case, the base station may determine that the RD is S1 to S3, since the first PDSCH ends earliest in the first slot.

In another example, a first slot may have one PDSCH from S1 to S13 and another PDSCH from S7 to S8. According to the first example, the base station may determine the RD based on the PDSCH that ends earliest, without considering where the PDSCH started in the COT. Thus, the base station may determine that the RD extends from S1 to S8.

According to a second example, the base station may determine the RD based on the earliest ending PDSCH and also considering whether the PDSCH starting early in the TxOP has a PDCCH starting early in the TxOP. The term "early" may be defined as starting within the first X symbols or Xms of the COT. X may correspond to an integer value such that X symbols corresponds to the number of symbols. In this case, using the same example as above, the base station may determine that the RD is from S1 to S13 because the PDSCHs from S1 to S13 start early in the COT. When the PDSCH is transmitted with multiple SCSs, the RD determination technique may be applied separately for each SCS, so that there are several PDSCHs for each SCS. The RD may be determined based on the maximum or minimum RD determined across all SCSs. The RD may be determined and applied for each SCS. Thus, for multiple SCSs, the base station may determine and apply multiple RDs.

The RD determination technique previously described may also be applied at the CBG level when CBG-based feedback/transmission is used. Thus, the RD may be based on the first CBG of the PDSCH that ends earliest, or on the first CBG of the PDSCH that starts early in the TxOP. When there are two PDSCHs, such that the first CBG of the first PDSCH occurs from slots S1-S2 and the first CBG of the second PDSCH occurs from slots S1-S4, the duration may be determined as slots S1-S2, since the first CBG of the first PDSCH ends earliest. The RD may also be based on the first CBG of the PDSCH that starts within a certain time period relative to the beginning of the COT. When multiple CBGs are transmitted with multiple SCSs, the RD may be determined for each SCS or without regard to the SCS. Thus, the first CBG of the PDSCH may be used for each SCS. The duration may be determined based on the maximum RD determined using the different techniques or based on the minimum RD determined using the different techniques.

The base station may therefore determine RD based on a maximum value of RD determined using any of the techniques described herein. In yet another example, the determined value may have a lower bound such that RD is not less than a predetermined minimum value, such as 0.25 ms.

The reference transmission determination component 520 may apply any of a variety of techniques to determine the reference transmission 524. The component 520 may determine the reference transmission based on, for example, the RD. In one example, the component 520 may determine which PDSCH to use as the reference PDSCH to determine the CW update.

The base station may identify the reference PDSCH as a PDSCH transmission that starts within an RD identified at the start of the COT. The base station may identify the reference PDSCH as a PDSCH transmission that ends within an RD identified at the start of the COT. The base station may identify the reference transmission based on a CBG that is within the RD or that at least partially overlaps with the RD. The base station may identify the reference PDSCH as any PDSCH transmission whose PDCCH was transmitted within an RD. FIG. 7A illustrates an example in which any PDSCH transmission that starts within an RD identified at the start of the COT may be considered for CW updating, e.g., may be used as a reference PDSCH transmission. Both PDSCH-1 and PDSCH-2 are used as reference PDSCH transmissions because both transmissions start within an RD. FIG. 7B illustrates an example in which a PDSCH transmission that ends within an RD identified at the start of the COT may be used as a reference PDSCH transmission. PDSCH-1 is used as the reference PDSCH, but PDSCH-2 is not considered as the reference PDSCH because PDSCH-2 does not end within the RD. Figure 7C shows an example where a PDSCH CBG that is within/overlaps with the RD may be used as a reference transmission. PDSCH-1 may be used in its entirety as the reference PDSCH, while the CBG of PDSCH-2 that is within the RD may be used as the reference CBG for determining CW updates.

Component 520 may also determine the reference transmission directly, for example based on 526, without first determining the RD as in 528. For example, the base station may determine that one or more PDSCH transmissions are reference PDSCHs based on the PDCCH corresponding to the PDSCH. The PDSCH whose PDCCH is transmitted within a predetermined time (e.g., the first X ms in the first slot) or within a predetermined number of symbols (e.g., the first X symbols of the first slot of the COT) may be used as the reference PDSCH and may be considered for CW update. Application of this technique to an example is further illustrated with reference to FIG. 10. CW adjustment component 534 receives reference transmission 524, explicit feedback 536 and/or implicit feedback 538, and determines whether to adjust CW size 542 for a subsequent LBT process based thereon. The LBT process may include, for example, a Category 4 LBT process. Explicit feedback 536 and/or implicit feedback 538 may relate to whether the determined reference transmission was successfully received by the receiving node.

Determining the reference duration when the reference transmission is punctured

Although the aspects are described using the example of a base station, this is merely an illustration of the concept. The aspects may be applied by a UE as well. As an example, when PDSCH puncturing is performed at the beginning of the COT, the base station may need to include additional slots in the RD so that additional PDSCH transmissions may be taken into account. According to a first example, the base station may decide not to include additional slots or PDSCHs when CBG-based feedback is available for at least one non-punctured CBG. FIG. 8A illustrates this case, where both PDSCH-1 and PDSCH-2 are punctured. PDSCH-1 does not have a non-punctured CBG, while PDSCH-2 has at least one CBG that is not punctured. In this case, the CW update may be determined using an RD that does not consider any other PDSCHs and/or additional slots.

When CBG-based feedback is not available, the base station may include additional slots or PDSCHs or CBGs in the CW update decision. Figure 8B illustrates this case, where an additional PDSCH-3 is considered for the RD decision, since PDSCH-1 does not provide CBG feedback. The additional PDSCH may be a full PDSCH or a partial PDSCH (e.g., the first CBG of the additional PDSCH). According to a second example, when puncturing occurs during RD or relative to the reference transmission, the base station may extend the RD and/or consider additional transmissions, e.g., including additional PDSCHs or additional slots, regardless of whether CBG feedback is available.

In some implementations, the base station may determine the RD and/or the reference transmission based on whether the PDSCH is broadcast without feedback. For example, the base station may determine the RD and/or the reference transmission without considering a broadcast PDSCH (e.g., system information or paging) that does not have ACK/NACK feedback. The base station may consider subsequent slots that have PDSCH transmissions with available ACK/NACK feedback. When the first slot of the COT includes a broadcast PDSCH, e.g., without including a unicast PDSCH, the base station may extend the RD to include the PDSCH transmitted in the subsequent slot. When the first slot of the COT includes both a broadcast PDSCH and a unicast PDSCH, the base station may consider the unicast PDSCH for the RD determination, e.g., ignore the broadcast PDSCH when determining the RD. In one example, the base station may use message 2 (MSG2) or a random access procedure as the reference transmission. For example, the base station may consider whether message 3 (MSG3) is received from the UE in response to the MSG2 transmission from the base station. MSG2 may include, for example, a random access response (RAR) transmitted from the base station to the UE in response to a first random access message from the UE. The first random access message from the UE may include, for example, a random access preamble to initiate a random access procedure. Thus, MSG3 from the UE may be considered to correspond to a positive feedback (e.g., similar to an ACK) from the UE in response to the MSG2 random access message. Thus, the MSG2 PDSCH/PDCCH may be used to determine the RD or reference PDSCH when MSG3 is considered for a CW update. In one example, MSG3 may be considered for a CW update when the communication between the base station and the UE includes a contention-free random access.

Determining reference duration using subband punctured reference transmission

Although the aspects are described using the example of a base station, this is merely an illustration of the concept. The aspects may be applied by a UE as well. As an example, when a first slot is partially punctured in time, the reference slot may be determined based on the partial slot and the next full slot when the next full slot is transmitted within the same TxOP. In some communications, puncturing may occur in both the time domain and the frequency domain. For example, NR-U may have a carrier with multiple LBT subbands, as opposed to, for example, LTE. Thus, in NR-U, puncturing occurs on some subbands and not on others. For example, a base station may prepare a PDSCH spanning three subbands (e.g., SB1, SB2, SB3), where subbands SB1 and SB3 pass the LBT but SB2 does not. The base station then punctures a portion of the PDSCH in SB2 and transmits it on SB1 and SB3. Therefore, the CW updates for SB1 and SB3 based on the ACK/NACK for this punctured PDSCH in SB2 may be pessimistic.

Due to the processing timeline, puncturing in frequency may also span more than one slot in the time domain. Unlike time domain puncturing where there is a single sub-slot, there may be more than one sub-slot (e.g., multiple sub-slots) for frequency domain puncturing. A sub-slot may also contain an unpunctured PDSCH (or the CBG of a punctured PDSCH). For example, some PDSCHs may be limited to SB1 or SB3, while other PDSCHs may span multiple sub-bands.

Some CBGs are not punctured and feedback of CBG levels is available to the base station.

According to some aspects, when there is at least one PDSCH (or CBG for which feedback is available) that is not punctured, the base station may determine RD 506 based at least in part on a partial slot with no additional slots. FIG. 9A illustrates an example in which a partial slot may be used as RD 506. As shown, PDSCH-1 is punctured, but PDSCH-6 is not, and RD may be based on the first slot. In some implementations, the base station does not consider the punctured PDSCH or punctured CBG in determining the CW adjustment.

According to some aspects, when there is at least one PDSCH that is punctured, the base station may determine RD 506 based at least in part on the partial slot and the next N slots until the end of the transmission opportunity (TxOP) is reached, where N is an integer. Thus, the N slots may indicate the number of slots N following the partial slot. FIG. 9B illustrates this case, where RD includes additional slots beyond the slots that include PDSCH-1, PDSCH-2, and PDSCH-3 because each of those PDSCHs is punctured in subband 2. The base station may extend RD to include additional slots until RD includes a slot where no PDSCH is punctured. For example, in FIG. 9B, slots are added to the partial slot until one slot is reached where PDSCH-4 and PDSCH-5 are not punctured because these particular PDSCH transmissions are transmitted on subbands 1 and 3, respectively, thereby avoiding subband 2, which failed the LBT. In one example, N may be a fixed number. The number of slots to consider after the partial slot for CW tuning may also be a function of the SCS. For example, for a 15 kHz or 30 kHz SCS, the base station may include one additional slot. For a 60 kHz SCS, the SCS base station may include two or more additional slots, for example two additional slots.

In a second example, the duration, e.g., the number of slots N, may be dynamic or variable. For example, additional slots after the partial slot may be considered until a non-punctured slot is determined or the end of the TxOP is reached.

In one implementation, a non-punctured slot may be a slot in which all of the PDSCHs are not punctured, e.g., there is no punctured PDSCH. In a second implementation, a non-punctured slot may be a slot in which at least one PDSCH is not punctured. In a third implementation, a non-punctured slot may be a slot in which at least one PDSCH CBG is not punctured.

When there are multiple partial slots with punctured PDSCH and full non-punctured slots, the base station may determine RD506 based on the full non-punctured slot and all partial slots. Alternatively, when there are multiple partial slots with punctured PDSCH and full non-punctured slots, the base station may determine RD506 based on the full non-punctured slot and one partial slot. The partial slot may be selected as the first partial slot of the COT or the partial slot before or just before the full non-punctured slot.

In some aspects, the base station may maintain a separate CW for each LBT subband. When the PDSCH is punctured in some subbands but transmitted on other subbands, the base station may determine the RD 506 or reference transmission (e.g., reference PDSCH) 524 separately for each subband. For each subband, the base station may determine the reference PDSCH as one or more CBGs of the full PDSCH (e.g., non-punctured PDSCH) or the unpunctured PDSCH. When the PDSCH is punctured in some subbands but transmitted on other subbands, the base station may determine an RD 506 that is common across multiple subbands. For example, the base station may continue to increase the RD 506 until each subband has at least one PDSCH or CBG of the unpunctured PDSCH.

CW updates or adjustments for UL-centric TxOPs

Some of the techniques for CW updates described above may be applied to a TxOP that includes at least one DL transmission. As described with respect to FIG. 12, the base station may update the CW based at least in part on downlink transmissions during RD. However, there are situations where a TxOP does not include a DL transmission, referred to as a UL-centric TxOP. Techniques for handling CW updates for a UL-centric TxOP are described next.

In one example, the base station may use the success or failure of the PUSCH and its PDCCH transmitted in the reference slot of the COT to determine the CW update. For the case where the TxOP includes a UL grant, the base station may employ the techniques previously described with respect to Figures 5, 6A, and 6B to determine the RD and also to determine which reference transmission (e.g., which reference PUSCH) to consider for the CW update.

The base station may determine RD on a slot basis using the techniques previously described with respect to Figures 5 and 6A. Instead of considering the SCS of the PDSCH, the base station may consider the SCS of the PDSCH for which the PUSCH transmission is scheduled. For techniques 509-511, the base station may determine RD as a function of, for example, the minimum SCS for the PDCCH supported by the base station or the minimum SCS actually used by the base station to transmit the PDCCH at the beginning of the COT.

The base station may determine the RD based on the subslot scheduling techniques previously described. For example, the technique 515 for determining the symbol-based RD may be equally applied herein. Instead of determining which PDSCH ends earliest, the subslot scheduling technique may determine the RD based on which PDSCH ends earliest.

In another example, the base station may determine the RD and/or the reference transmission based on the PDCCH. For example, the base station may determine the RD based on a PUSCH transmission, which is transmitted within a first predetermined time (e.g., X ms) from the beginning of the COT or within a predetermined number of symbols (e.g., X symbols) in the first slot of the COT. Figure 10 shows an example 1000 of a predetermined time/number of symbols 1014 within the first slot 1016 of the COT. In one example, the base station may determine the reference PUSCH directly, for example, rather than determining a reference duration.

The base station may determine the reference PUSCH by including each PUSCH transmission for which its PDCCH was transmitted in the RD. Any of the previously described techniques for determining the reference transmission may also be applied together to determine the reference PUSCH directly or based on the determined RD or other factors.

FIG. 13 illustrates an example method for a base station to determine at least one PDCCH transmission transmitted during a RD. The base station updates the CW based at least in part on an uplink transmission that includes a PDCCH transmission transmitted during a RD.

TxOP with both DL and UL

According to one example, the base station may schedule DL and UL transmissions in a TxOP, and the base station may perform CW updates based on ACK/NACK feedback for DL transmissions while ignoring the success or failure of UL transmissions. Application of this technique may be based on the beginning of a COT that includes at least one DL transmission.

Due to, for example, broadcast transmissions in NR-U, the beginning part of the COT may not contain DL transmissions with corresponding ACK/NACK feedback. Thus, in some aspects, UL and/or DL transmissions may be used to update the CW size when the COT contains both UL and DL transmissions. For example, the base station may take into account ACK/NACK feedback for DL transmissions when the initial part of the COT includes DL transmissions that can be used for CW updates. In some cases, the base station may determine its CW updates based on UL transmissions while ignoring DL transmissions. According to a second technique, the base station may take into account both ACK/NACK feedback of DL transmissions and success/failure of UL transmissions to update or adjust the CW size.

FIG. 14 illustrates an example method of CW adjustment or updating in which a base station determines whether to use a reference PDSCH transmission or a reference PUSCH transmission to update the CW size. The base station may determine to use a PDSCH transmission without a PUSCH transmission to update the CW when a PDSCH has associated feedback and is transmitted during a time period from the beginning of the COT. The base station may determine to use a PUSCH transmission without a PDSCH transmission to update the CW when a PDSCH with associated feedback is not transmitted during a time period from the beginning of the COT. In another example, the base station may use both PDSCH and PUSCH transmissions to update its CW.

12 is a flowchart 1200 of a method of wireless communication. In one example, the method may be performed by a base station or a component of a base station (e.g., base station 102, 180, 310, device 1602, 1602'; processing system 1714 that may include memory 376 and may be the entire base station 310 or a component of the base station 310, e.g., TX processor 316, RX processor 370 and/or controller/processor 375). In another example, the method may be performed by a UE or a component of a UE (e.g., UE 104, 350, device 1602, 1602'; processing system 1714 that may include memory 360 and may be the entire UE 350 or a component of the UE 350, e.g., TX processor 368, RX processor 356 and/or controller/processor 359). Optional aspects are shown in dashed lines.

At 1202, the device determines an RD for the COT, the RD being based at least in part on the SCS and based on receiving a physical downlink shared channel (PDSCH) transmission. For example, the determination may be performed by a reference duration determination component 1612 of the apparatus 1602. Examples of such RD determination are described, for example, in connection with FIG. 6A and FIG. 6B. The reference duration may be determined based on a minimum SCS supported by the base station. The reference duration may be determined based on a minimum SCS used by the device at the beginning of the COT. The device may determine a first reference duration for a first SCS and a second reference duration for a second SCS, and the device updates the CW based on a first shared channel transmission based on the first SCS for the first duration and a second downlink transmission based on the second SCS for the second duration. If the method is performed by a base station, the shared channel transmission may include a PDSCH. If the method is performed by a UE, the shared channel transmission may include a PUSCH. The reference duration may be determined based on the maximum of a predetermined minimum duration, the minimum SCS supported by the device, or the minimum SCS used by the device at the beginning of the COT.

The reference duration of the COT may be determined based on the number of slots, for example, as described with respect to FIG. 6A. The reference duration of the COT may be determined based on the number of symbols, for example, as described with respect to FIG. 6B.

The COT may include a first slot having a plurality of symbols, and a reference duration of the COT may be determined based on a number of symbols of a PDSCH transmission transmitted during the first slot of the COT. As an example, the reference duration may be determined based on a PDSCH transmission having a symbol that ends earliest in the first slot of the COT. The reference duration may be determined based on a PDSCH transmission having a symbol that starts earliest in the first slot of the COT or having a PDSCH transmitted within the earliest symbol in the first slot of the COT. The reference duration may be determined based on a PDSCH transmission that starts within a predetermined number of symbols or a predetermined time from the beginning of the first slot of the COT, or based on a PDSCH that has a PDCCH that starts within a predetermined number of symbols or a predetermined time from the beginning of the first slot of the COT.

The first reference duration may be determined for a first SCS used in a first slot of the COT, and the second reference duration may be determined for a second SCS used in the first slot of the COT. The reference duration may be determined based on the number of symbols of the first CBG of the PDSCH transmission transmitted during the COT.

The reference duration may be determined based at least in part on whether CBG-based feedback is available for at least one non-punctured CBG of the shared channel transmission when puncturing is performed at the beginning of the COT, and the reference duration is extended when CBG-based feedback is not available for at least one non-punctured CBG.

Determining the reference duration may include, at 1202, extending the reference duration when a shared channel transmission is punctured during the reference duration.

The reference duration or reference PDSCH may be determined based on whether the shared channel transmission includes a broadcast without feedback. The CW may be updated based on the determined reference PDSCH transmission. The reference duration may be extended to include a shared channel transmission with feedback. The reference PDSCH may be defined based on a PDSCH that occurs during the reference duration and has feedback.

The reference duration may further be determined based on whether at least one non-punctured PDSCH transmission or at least one non-punctured CBG is transmitted during the reference duration. For example, the reference duration may be extended when a non-punctured PDSCH or a non-punctured CBG is transmitted during the reference duration.

The reference duration may further be determined based on whether the shared channel transmission is punctured for the reference duration, and the reference duration may be extended a number of slots when the shared channel transmission is punctured for the reference duration. The reference duration may be extended by the base station to the end of the shared channel transmission. The number of slots may include a predetermined number of slots. The number of slots may be based on at least one of the shared channel transmission or the non-punctured slots for the end of the shared channel transmission. The non-punctured slots may include at least one of a first slot in which all PDSCH transmissions are not punctured, a second slot in which at least one PDSCH transmission is not punctured, and/or a third slot in which at least one PDSCH CBG is not punctured. The reference duration may be extended to include multiple slots including punctured shared channel transmissions and one slot including at least one PDSCH transmission or CBG that is not punctured. The multiple slots may include a punctured shared channel transmission, and the reference duration may be determined to include a slot that includes at least one unpunctured PDSCH transmission or CBG and at least one of the multiple slots that includes the punctured shared channel transmission. The reference duration may be determined for each subband. The reference duration may be determined commonly for the multiple subbands.

At 1204, the device updates the CW based at least in part on receiving the PDSCH transmission during the reference duration. The updating may be performed, for example, by the CW adjustment component 1616 of the apparatus 1602. Updating the CW may include one of doubling the CW based at least in part on a negative acknowledgment received by the device for the shared channel transmission or assigning a predetermined minimum value (CW_min) to the CW based at least in part on an acknowledgment received by the device for the shared channel transmission. Updating the CW may include doubling the CW based at least in part on no acknowledgment received by the device for the shared channel transmission.

As shown at 1203, the device may also determine a reference PDSCH transmission based on a relationship of the reference duration to a reference PDSCH transmission or to a PDCCH transmission to the reference PDSCH transmission. The determination may be performed, for example, by a reference transmission determination component 1614 of the apparatus 1602. The CW may be updated, for example, at 1204, based on the determined reference PDSCH transmission. The reference PDSCH transmission may be determined based on a PDCCH transmission associated with at least one reference PDSCH transmission transmitted within a predetermined amount of time or a predetermined number of symbols from the beginning of the COT. The reference PDSCH transmission may be determined based on at least one of a PDSCH that starts within the reference duration of the COT, a PDSCH that ends within the reference duration of the COT, a CBG of the PDSCH that at least partially overlaps with the reference duration, and/or a PDSCH having a PDCCH transmitted within the reference duration.

As shown at 1205, the device may use the updated CW determined at 1204 to perform an LBT, for example, to transmit a shared channel communication to the UE. The LBT may be performed, for example, by the receiving component 1604 of the apparatus 1602. The communication between the device and the UE may be performed over a shared spectrum or an unlicensed spectrum. For example, the communication may be based on NR-U.

Figure 13 is a flowchart 1300 of a method of wireless communication. The method may be performed by a base station or a component of a base station (e.g., base station 102, 180, 310, device 1602, 1602'; processing system 1714, which may include memory 376 and may be the entire base station 310 or a component of the base station 310, e.g., TX processor 316, RX processor 370 and/or controller/processor 375). Optional aspects are indicated with dashed lines.

At 1302, the base station determines an RD for the COT, the RD being based at least in part on the SCS. The RD may be determined, for example, by a reference duration determination component 1612 of the apparatus 1602. The reference duration may be determined based on at least one of a predetermined minimum duration, a minimum SCS supported by the base station, and/or a minimum SCS used by the base station for the PDCCH at the beginning of the COT. The reference duration for the COT may be determined based on a slot number. The reference duration for the COT may be determined based on a symbol number. The COT may include a first slot having a plurality of symbols, and the reference duration for the COT may be determined based on a symbol number of PDCCH transmissions transmitted during the COT. The reference duration may be determined based on a reference PDCCH transmission having at least one of a symbol ending earliest within the first slot of the COT and/or a symbol starting earliest within the first slot of the COT. The reference duration may be determined based on a reference PDCCH transmission starting within a predetermined number of symbols or a predetermined time from the beginning of the COT.

The first reference duration may be determined for a first SCS used for a first PDCCH in the COT, and the second reference duration may be determined for a second SCS used for a second PDCCH in the COT.

The reference duration may be determined for each subband. The reference duration may be determined in common for multiple subbands.

At 1304, the base station determines a reference PDCCH transmission to be transmitted during the reference duration. The reference PDCCH transmission may be determined, for example, by the reference transmission determination component 1614 of the device 1602. An example of a reference transmission determined based on a PDCCH is described with respect to FIG. 10.

At 1306, the base station may update the CW based at least in part on the uplink transmission having at least one reference PDCCH transmission transmitted during the reference duration. The CW may be updated, for example, by the CW adjustment component 1616 of the apparatus 1602. Updating the CW may include one of doubling the CW based at least in part on a negative acknowledgment received by the base station for the downlink transmission or assigning a predetermined minimum value to the CW based at least in part on an acknowledgment received by the base station for the downlink transmission. Updating the CW may include doubling the CW based at least in part on no acknowledgment received by the base station for the downlink transmission. The CW may be updated based on each uplink transmission having a PDCCH transmission transmitted during the reference duration. The CW may be updated based on each uplink transmission having a PDCCH transmission transmitted within a predetermined amount of time or a predetermined number of symbols from the start of the COT.

As shown at 1308, the base station may use the updated CW determined at 1306 to perform an LBT, for example, to transmit a downlink communication to the UE. The LBT may be performed, for example, by the receiving component 1604 of the device 1602. The communication between the base station and the UE may be performed over a shared spectrum or an unlicensed spectrum. For example, the communication may be based on NR-U.

Figure 14 is a flowchart 1400 of a method of wireless communication. The method may be performed by a base station or a component of a base station (e.g., base station 102, 180, 310, device 1602, 1602'; processing system 1714, which may include memory 376 and may be the entire base station 310 or a component of the base station 310, e.g., TX processor 316, RX processor 370 and/or controller/processor 375). Optional aspects are indicated with dashed lines.

As shown at 1402, the base station determines the duration of the COT. The determination may include, for example, aspects as described with respect to the determination for either 1202 or 1302. The determination may be performed, for example, by a reference duration determination component 1612 of the device 1602.

At 1404, the base station determines whether to use a reference PDSCH transmission or a reference PUSCH transmission to update the CW. The determination may be performed, for example, by the reference transmission determination component 1614 of the apparatus 1602. For example, the base station may determine to use a PDSCH transmission without a PUSCH transmission to update the CW when a PDSCH has associated feedback and is transmitted during a time period from the beginning of the COT. The base station may determine to use a PUSCH transmission without a PDSCH transmission to update the CW when a PDSCH with associated feedback is not transmitted during a time period from the beginning of the COT. The base station may determine to use both a PDSCH transmission and a PUSCH transmission to update the CW.

At 1406, the base station updates the CW based on at least one of the PDSCH or PUSCH and the reference duration. The CW may be updated, for example, by a CW adjustment component 1616 of the apparatus 1602. Updating the CW may include one of doubling the CW based at least in part on a negative acknowledgment received by the base station for the downlink transmission or assigning a predetermined minimum value to the CW based at least in part on an acknowledgment received by the base station for the downlink transmission. Updating the CW may include doubling the CW based at least in part on no acknowledgment received by the base station for the downlink transmission.

As shown at 1408, the base station may use the updated CW determined at 1406 to perform an LBT, for example, to transmit a downlink communication to the UE. The LBT may be performed, for example, by the receiving component 1604 of the apparatus 1602. The communication between the base station and the UE may be performed over a shared spectrum or an unlicensed spectrum. For example, the communication may be based on NR-U.

FIG. 16 is a conceptual data flow diagram 1600 illustrating data flow between different means/components in an example apparatus 1602. The apparatus 1602 may be, for example, a base station or a component of a base station in communication with a UE, for example, a device 1650. In some aspects, the apparatus may include a UE or a component of a UE. The apparatus may include a receiving component 1604 configured to receive a communication from the device 1650 and a transmitting component 1610 configured to transmit a communication to the device. The apparatus may use, for example, an LBT before transmitting to the device. The apparatus 1602 may include an RD determination component 1612 configured to determine an RD duration as described with respect to any of 1202, 1302, 1402, a reference transmission determination component 1614 configured to determine a reference transmission as described with respect to any of 1203, 1304, 1404, and a CW size adjustment component 1616 that determines whether to update the CW and/or generates an adjusted CW 1617 based on the reference transmission 1615 or the RD 1613, for example, as described with respect to any of 1204, 1306, 1406. The components 1612, 1614, and 1616 perform one or more techniques described above with respect to FIG. 4, FIG. 5, and FIG. 12.

The device 1602 may include additional components that perform each of the blocks of the algorithms in the above-mentioned flowcharts of FIG. 4, 12-14. Thus, each block in the above-mentioned flowcharts of FIG. 4, 12-14 may be performed by one component, and the device may include one or more of those components. The components may be one or more hardware components specifically configured to perform the described process/algorithm, implemented by a processor configured to perform the described process/algorithm, stored in a computer-readable medium for implementation by a processor, or some combination thereof.

17 is a diagram 1700 illustrating an example of a hardware implementation for an apparatus 1602' using a processing system 1714. The processing system 1714 may be implemented with a bus architecture generally represented by a bus 1724. The bus 1724 may include any number of interconnecting buses and bridges depending on the particular application and overall design constraints of the processing system 1714. The bus 1724 links together various circuits including one or more processors and/or hardware components represented by the processor 1704, components 1604, 1606, 1610, 1612, 1614, 1616, 1640, and computer readable media/memory 1706. The bus 1724 may also connect 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 further.

The processing system 1714 includes an RD determination component 1612, a reference transmission determination component 1614, and a CW size adjustment component 1616. The components 1612, 1614, 1616 perform one or more of the techniques described above with respect to Figures 4, 5, and 12.

The processing system 1714 also includes a TxOP having UL and DL Tx processing components 1640 for performing the techniques described above with respect to FIG. 14, an uplink-centric TxOP processing component 1606 for performing the techniques described above with respect to FIG. 13, and a CW adjustment component 1616 for performing the techniques described above with respect to FIG. 15.

The processing system 1714 may be coupled to a transceiver 1710. The transceiver 1710 is coupled to one or more antennas 1720. The transceiver 1710 provides a means for communicating with various other devices over a transmission medium. The transceiver 1710 receives signals from one or more antennas 1720, extracts information from the received signals, and provides the extracted information to the processing system 1714. Additionally, the transceiver 1710 receives information from the processing system 1714 and generates signals to be applied to the one or more antennas 1720 based on the received information. The processing system 1714 includes a processor 1704 coupled to a computer-readable medium/memory 1706. The processor 1704 is responsible for general processing, including the execution of software stored in the computer-readable medium/memory 1706. The software, when executed by the processor 1704, causes the processing system 1714 to perform various functions previously described for any particular device. The computer-readable medium/memory 1706 may be used to store data manipulated by the processor 1704 when executing software. The processing system 1714 further includes at least one of the components 1604, 1606, 1610, 1612, 1614, 1616, 1640. These components may be software components operating within the processor 1704 and residing/stored on the computer-readable medium/memory 1706, one or more hardware components coupled to the processor 1704, or some combination thereof.

In one configuration, the apparatus 1602 for wireless communication is a base station including means for determining RD, means for determining reference transmission and means for adjusting CW, means for processing UL-centric TxOP and means for processing TxOP having both UL and DL, and means for performing LBT based on the updated CW. The aforementioned means may be one or more of the aforementioned components of the apparatus 1602' and/or the processing system 1714 of the apparatus 1602' configured to perform the functions recited by the aforementioned means. As described above, the processing system 1714 may include the TX processor 316, 368, the RX processor 356, 370, and the controller/processor 359, 375. Thus, in one configuration, the aforementioned means may be the TX processor 316, 368, the RX processor 356, 370, and the controller/processor 359, 375 configured to perform the functions recited by the aforementioned means.

UL CW Update

The CW window update on the UE side may include whether the UE receives an uplink grant in a subframe, and the reference subframe may be based on the subframe in which the uplink grant is received (or a number of subframes before the subframe in which the uplink grant is received) and the immediately preceding subframe in which the UE transmitted an uplink transmission, e.g., an uplink shared transmission, using a type 1 channel access procedure. For example, if the UE transmits uplink transmissions, e.g., uplink shared channel transmissions, without gaps, the reference subframe may be the first subframe of consecutive transmissions. Thus, the first slot of the last uplink burst may be used to determine the CW update. However, there may be multiple switching points. FIG. 11 shows an example 1100 in which the UE transmits a PUSCH, switches to receiving a downlink transmission from the base station, and then switches back to the original uplink transmission. FIG. 11 shows that the UE may transmit a PUCCH before returning to transmitting a PUSCH. If the first subframe of a consecutive PUSCH transmission is used for the reference subframe, the PUSCH considered for the CW is not the PUSCH at the beginning of the COT.

Thus, instead of using the reference subframe on the uplink shared channel transmission as a reference without gaps, the reference subframe may be based on the first PUSCH in the COT. In Figure 11, this leads to using the first PUSCH before switching to downlink reception for the reference subframe to update the CW.

Thus, when a DL transmission occurs early within the COT and is the source of ACK/NACK information for the COT, the UE may update the CW (e.g., double the CW on failure and reset the CW to the minimum on success) based on whether a downlink transmission (e.g., PDCCH or PDSCH) during the COT was successfully received.

In another example, the UE may update the CW based on downlink reception within the UE-initiated COT. Thus, the downlink reception shown in FIG. 11 between the PUSCH and the PUCCH may be used by the UE to update the CW. The UE may use the downlink reception, for example, when it is within a time period from the beginning of the COT and/or when it is the source of feedback for the COT. For example, if the PDCCH and/or PDSCH are successfully received at the UE, the UE may reset the CW to a minimum value. If the PDCCH/PDSCH are not successfully received, the UE may increase (e.g., double) the CW size.

15 is a flowchart 1500 of a method of wireless communication. The method may be performed by a UE or a component of a UE (e.g., UE 104, 350, device 1802, 1802'; processing system 1914, which may include memory 360 and may be the UE 350 as a whole or a component of the UE 350, e.g., TX processor 368, RX processor 356 and/or controller/processor 359). Optional aspects are indicated with dashed lines.

At 1502, the UE determines an RD for the COT based on a first slot of a proximate set of uplink shared channel transmissions during the COT. The determination may be performed, for example, by a reference duration determination component 1812 of the apparatus 1802. The proximate set of uplink shared channel transmissions may include, for example, discontinuous uplink shared channel transmissions, as described with respect to FIG. 11.

At 1504, the UE updates the CW based at least in part on the uplink shared channel transmission during the reference duration. The determination may be performed, for example, by the reference transmission determination component 1814 of the device 1802. The CW may further be updated based on the downlink transmission during the COT.

As shown at 1506, the UE may use the updated CW determined at 1504 to perform an LBT, for example, to transmit a downlink communication to the UE. The LBT may be performed, for example, by the receiving component 1804 and/or the transmitting component 1810 of the apparatus 1802. The communication between the base station and the UE may be performed over a shared spectrum or an unlicensed spectrum. For example, the communication may be based on NR-U.

FIG. 18 is a conceptual data flow diagram 1800 illustrating data flow between different means/components in an exemplary apparatus 1802. The apparatus may be a UE or a component of a UE in communication with a base station 1850. The apparatus may include a receiving component configured to receive downlink communications from the base station 1850. The apparatus may include a transmitting component configured to transmit uplink communications to the base station. The apparatus includes a reference duration determination component 1812 configured to determine a reference duration of the COT, the reference duration being based on a first slot of a proximate set of uplink shared channel transmissions during the COT, for example, as described with respect to 1502 in FIG. 15. The apparatus includes a reference transmission determination component 1814 configured to determine a reference transmission, for example, as described with respect to FIG. 15. For example, the apparatus may include a UL and DL transmission processing component 1806 configured to assist in determining the reference communication, whether uplink and/or downlink, for example. The apparatus includes a CW adjustment component 1816 configured to update the CW based at least in part on the uplink shared channel transmission during the reference duration, e.g., as described with respect to 1506 in FIG. 15.

The apparatus may include additional components that perform each of the blocks of the algorithms in the above-mentioned flowcharts of Figures 4 and 15. Thus, each block in the above-mentioned flowcharts of Figures 4 and 15 may be performed by one component, and the apparatus may include one or more of those components. The components may be one or more hardware components specifically configured to perform the described process/algorithm, implemented by a processor configured to perform the described process/algorithm, stored in a computer-readable medium for implementation by a processor, or some combination thereof.

19 is a diagram 1900 illustrating an example of a hardware implementation of an apparatus 1802' utilizing a processing system 1914. The processing system 1914 may be implemented using a bus architecture generally represented by a bus 1924. The bus 1924 may include any number of interconnecting buses and bridges depending on the specific application and overall design constraints of the processing system 1914. The bus 1924 links together various circuits including the processor 1904, components 1804, 1806, 1810, 1812, 1814, 1816, and one or more processors and/or hardware components represented by a computer readable medium/memory 1906. The bus 1924 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 further.

The processing system 1914 may be coupled to a transceiver 1910. The transceiver 1910 is coupled to one or more antennas 1920. The transceiver 1910 provides a means for communicating with various other devices over a transmission medium. The transceiver 1910 receives signals from the one or more antennas 1920, extracts information from the received signals, and provides the extracted information to the processing system 1914, specifically to the receiving component 1804. In addition, the transceiver 1910 receives information from the processing system 1914, specifically to the transmitting component 1810, and generates signals to be applied to the one or more antennas 1920 based on the received information. The processing system 1914 includes a processor 1904 coupled to a computer-readable medium/memory 1906. The processor 1904 is responsible for general processing, including the execution of software stored in the computer-readable medium/memory 1906. The software, when executed by the processor 1904, causes the processing system 1914 to perform the various functions described above for any particular device. The computer-readable medium/memory 1906 may also be used to store data that is manipulated by the processor 1904 when executing the software. The processing system 1914 further includes at least one of the components 1804, 1806, 1810, 1812, 1814, 1816. The components may be software components running in the processor 1904 and residing/stored in the computer-readable medium/memory 1906, one or more hardware components coupled to the processor 1904, or some combination thereof. The processing system 1914 may be a component of the base station 310 and may include the memory 376 and/or at least one of the TX processor 316, the RX processor 370, and the controller/processor 375. Alternatively, the processing system 1914 may be an entire base station (e.g., see 310 in FIG. 3).

In one configuration, the apparatus 1802/1802' for wireless communication includes means for determining a reference duration of the COT, the reference duration being based on a first slot of a most recent set of uplink shared channel transmissions during the COT, and means for updating the CW being based at least in part on the uplink shared channel transmissions during the reference duration. The aforementioned means may be one or more of the aforementioned components of the processing system 1914 of the apparatus 1802 and/or the apparatus 1802' configured to perform the functions recited by the aforementioned means. As described above, the processing system 1914 may include the TX processor 316, the RX processor 370, and the controller/processor 375. Thus, in one configuration, the aforementioned means may be the TX processor 316, the RX processor 370, and the controller/processor 375 configured to perform the functions recited by the aforementioned means.

For example, techniques have been described for determining reference transmissions for contention window updates for NR-U. Although these techniques have been described in the context of 5G NR, these techniques may also be applicable to other multiple access technologies and telecommunications standards that employ these technologies.

The following examples are illustrative only and may be combined, without limitation, with other embodiments or aspects of the teachings described herein.

Example 1 is an apparatus for wireless communication in a wireless device, the wireless device including a memory and at least one processor coupled to the memory, the memory and the at least one processor configured to: determine a reference duration of a COT, the reference duration based at least in part on an SCS and based on receiving a PDSCH transmission; and update a CW based at least in part on receiving a PDSCH transmission during the reference duration.

In example 2, the apparatus of example 1 further includes the PDSCH transmission being a non-punctured PDSCH transmission.

In Example 3, the apparatus of Example 1 or Example 2 further includes the reference duration including a non-punctured slot that includes a PDSCH transmission or an end of a PDSCH transmission.

In Example 4, the apparatus of any of Examples 1-3 further includes the reference duration being further determined based on whether the PDSCH transmission is punctured during the reference duration, and the reference duration being extended by a number of slots when the PDSCH transmission is punctured during the reference duration.

In Example 5, the apparatus of any of Examples 1-4 further includes extending the reference duration until an end of the shared channel transmission by the base station or until a predetermined number of slots.

In Example 6, the apparatus of any of Examples 1-5 further includes determining the reference duration based on a PDSCH transmission beginning within a predetermined number of symbols or a predetermined time from a beginning of a slot.

In Example 7, the apparatus of any of Examples 1-6 further includes that updating the CW includes one of increasing the CW based at least in part on a negative acknowledgment received by the wireless device for the PDSCH transmission or assigning a predetermined minimum value (CW_min) to the CW based at least in part on an acknowledgement received by the wireless device for the PDSCH transmission.

In Example 8, the apparatus of any of Examples 1-7 further includes, updating the CW includes increasing the CW based at least in part on no acknowledgment being received by the wireless device for the PDSCH transmission.

In Example 9, the apparatus of any of Examples 1-8 further includes the wireless device determining a first reference duration for the first SCS and a second reference duration for the second SCS, and the wireless device updating the CW based on a first shared channel transmission based on the first SCS during the first reference duration and a second shared channel transmission based on the second SCS during the second reference duration.

In Example 10, the apparatus of any of Examples 1-9 further includes the memory and the at least one processor further configured to determine the at least one reference PDSCH transmission based on a control channel transmission for the at least one reference PDSCH transmission transmitted within a predetermined amount of time or a predetermined number of symbols from a start of the COT.

In Example 11, the apparatus of any of Examples 1-10 further includes determining the at least one reference PDSCH transmission based on at least one of at least one reference PDSCH transmission starting within the reference duration, at least one reference PDSCH transmission ending within the reference duration, at least one code block group (CBG) of the at least one reference PDSCH transmission at least partially overlapping with the reference duration, or at least one reference PDSCH transmission having a control channel transmission within the reference duration.

In Example 12, the apparatus of any of Examples 1-11 further includes determining the reference duration or the reference PDSCH transmission based on whether the PDSCH transmission includes a broadcast without feedback, and updating the CW based on the reference PDSCH transmission determined by the wireless device.

In Example 13, the apparatus of any of Examples 1-12 further includes extending the reference duration to include a PDSCH transmission having feedback.

In Example 14, the apparatus of any of Examples 1-13 further includes the reference duration being determined based on whether at least one non-punctured code block group (CBG) is transmitted during the reference duration, and the reference duration being extended when a non-punctured shared channel transmission or a non-punctured CBG is not transmitted during the reference duration.

In Example 15, the apparatus of any of Examples 1-14 further includes the reference duration being based on a non-punctured slot that includes at least one of a first slot in which all shared channel transmissions are not punctured, a second slot that includes at least one non-punctured shared channel transmission, or a third slot in which at least one shared channel CBG is not punctured.

In Example 16, the apparatus of any of Examples 1-15 further includes extending the reference duration to include a plurality of slots including a punctured shared channel transmission and one slot including at least one non-punctured shared channel transmission or a non-punctured CBG.

In Example 17, the apparatus of any of Examples 1-16 further includes a plurality of slots including punctured transmissions, and the reference duration is determined to include one slot including at least one non-punctured shared channel transmission or non-punctured CBG and at least one of the plurality of slots including a punctured downlink transmission.

Example 18 is an apparatus for wireless communication in a wireless device, the wireless device including means for determining a reference duration of a COT, the reference duration based at least in part on an SCS and based on receiving a PDSCH transmission, and means for updating a CW based at least in part on receiving a PDSCH transmission during the reference duration.

In Example 19, the apparatus of Example 18 further includes means for performing the method (or apparatus-based method) of any of Examples 2-17.

Example 20 is a method for wireless communication in a wireless device, comprising performing the method (or apparatus method) of any of Examples 1-17.

Example 21 is a computer-readable medium storing computer-executable code for wireless communication in a wireless device, the code, when executed by a processor, causing the processor to perform a method (or apparatus method) of any of Examples 1-17.

Example 22 is an apparatus for wireless communication by a wireless device in a base station, the wireless device including a memory and at least one processor coupled to the memory, the memory and the at least one processor configured to: determine a reference duration of a COT, the reference duration based at least in part on an SCS; determine at least one reference PDCCH transmission transmitted during the reference duration; and update a CW based at least in part on an uplink transmission having the at least one reference PDCCH transmission transmitted during the reference duration.

In Example 23, the apparatus of Example 22 further includes determining the reference duration based on at least one of a predetermined minimum duration, a minimum SCS supported by the base station, or a minimum SCS used by the base station for the PDCCH at the beginning of the COT.

In example 24, the device of example 22 or example 23 further includes determining the reference duration based on a number of slots or a number of symbols.

In Example 25, the apparatus of any of Examples 22-24 further includes the COT including a first slot having a plurality of symbols, and the reference duration is determined based on a number of symbols of the PDCCH transmission transmitted during the COT.

In Example 26, the apparatus of any of Examples 22-25 further includes determining the reference duration based on at least one reference PDCCH transmission having at least one of a symbol that ends earliest within the first slot of the COT or a symbol that starts earliest within the first slot of the COT.

In Example 27, the apparatus of any of Examples 22-26 further includes determining the reference duration based on at least one reference PDCCH transmission beginning within a predetermined number of symbols or a predetermined time from a beginning of the COT.

In Example 28, the apparatus of any of Examples 22-27 further includes determining a first reference duration for a first SCS used for a first PDCCH in the COT and determining a second reference duration for a second SCS used for a second PDCCH in the COT.

In Example 29, the apparatus of any of Examples 22-28 further includes updating the CW based on each uplink transmission having a PDCCH transmission transmitted during the reference duration.

In Example 30, the apparatus of any of Examples 22-29 further includes updating the CW based on each uplink transmission having a PDCCH transmission transmitted within a predetermined amount of time or a predetermined number of symbols from a start of the COT.

In Example 31, the apparatus of any of Examples 22-30 further includes a reference duration being determined for each subband, or a reference duration being determined commonly for multiple subbands.

Example 32 is an apparatus for wireless communications in a base station, the apparatus including means for determining a reference duration of a COT, the reference duration based at least in part on an SCS, and means for determining at least one reference PDCCH transmission transmitted during the reference duration and updating a CW based at least in part on an uplink transmission having at least one reference PDCCH transmission transmitted during the reference duration.

In Example 33, the apparatus of Example 32 further includes means for performing the method (or apparatus-based method) of any of Examples 23-31.

Example 34 is a method for wireless communication in a base station, comprising performing the method (or apparatus method) of any of Examples 22-31.

Example 35 is a computer-readable medium storing computer-executable code for wireless communication in a base station, the code, when executed by a processor, causing the processor to perform a method (or apparatus method) of any of Examples 22-31.

Example 36 is an apparatus for wireless communication in a base station, the apparatus including a memory and at least one processor coupled to the memory, the memory and the at least one processor configured to determine a reference duration of the COT, determine whether to use a reference PDSCH transmission or a reference PUSCH transmission to update the CW, and update the CW based on at least one of the reference PDSCH transmission or the reference PUSCH transmission and the reference duration.

In Example 37, the apparatus of Example 36 further includes the base station determining to use a PDSCH transmission without using a PUSCH transmission to update the CW when the PDSCH transmission has associated feedback and is transmitted during the time period from the beginning of the COT.

Example 38 is an apparatus for wireless communication in a base station, the apparatus including means for determining a reference duration of a COT, means for determining whether to use a reference PDSCH transmission or a reference PUSCH transmission to update the CW, and means for updating the CW based on at least one of the reference PDSCH transmission or the reference PUSCH transmission and the reference duration.

Example 40 is a computer-readable medium storing computer-executable code for wireless communication in a base station, the code, when executed by a processor, causing the processor to determine a reference duration of the COT, determine whether to use a reference PDSCH transmission or a reference PUSCH transmission to update the CW, and update the CW based on at least one of the reference PDSCH transmission or the reference PUSCH transmission and the reference duration.

Example 41 is an apparatus for wireless communication in a UE, the apparatus including a memory and at least one processor coupled to the memory, the memory and the at least one processor configured to: determine a reference duration of a COT, the reference duration being based on a first slot of a most recent set of uplink shared channel transmissions during the COT; and update a CW based at least in part on the uplink shared channel transmissions during the reference duration.

Example 42 is an apparatus for wireless communications in a UE, the apparatus including: means for determining a reference duration of a COT, the reference duration being based on a first slot of a most recent set of uplink shared channel transmissions during the COT; and means for updating a CW based at least in part on the uplink shared channel transmissions during the reference duration.

Example 43 is a computer-readable medium storing computer-executable code for wireless communications in a UE, which, when executed by a processor, causes the processor to determine a reference duration of a COT, where the reference duration is based on a first slot of a most recent set of uplink shared channel transmissions during the COT, and to update a CW based at least in part on the uplink shared channel transmissions during the reference duration.

It should be understood that the particular order or hierarchy of the blocks in the disclosed processes/flowcharts is illustrative of example approaches. Based on design preferences, it should be understood that the particular order or hierarchy of the blocks in the processes/flowcharts may be rearranged. Further, some blocks may be combined or omitted. The accompanying method claims present elements of the various blocks in an example order, and are not limited to the particular order or hierarchy presented.

The above 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 general principles defined herein may be applied to other aspects. Thus, the claims are not intended to be limited to the aspects shown herein but are to be accorded the widest scope consistent with the claim language, and references to elements in the singular are intended to mean "one or more" and not "one and only," unless so expressly stated. The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any aspect described herein as "exemplary" should not necessarily be construed as preferred or advantageous over other aspects. Unless otherwise expressly stated, the term "some" refers to one or more. Combinations such as "at least one of A, B, or C," "one or more of A, B, or C," "at least one of A, B, and C," "one or more of A, B, and C," and "A, B, C, or any combination thereof" include any combination of A, B, and/or C and may include multiple As, multiple Bs, or multiple Cs. Specifically, combinations such as "at least one of A, B, or C," "one or more of A, B, or C," "at least one of A, B, and C," "one or more of A, B, and C," and "A, B, C, or any combination thereof" may be A only, B only, C only, A and B, A and C, B and C, or A and B and C, and any such combination may include one or more members of A, B, or C. All structural and functional equivalents to the elements of the various embodiments described throughout this disclosure that are known or that later become known to those skilled in the art are intended to be expressly incorporated herein by reference and encompassed by the claims. Moreover, nothing disclosed herein is intended to be made public, regardless of whether such disclosure is expressly recited in the claims. Words such as "module," "mechanism," "element," "device," and the like may not be substitutes for the word "means." Thus, no claim element should be construed as a means plus function unless the element is expressly recited using the phrase "means for."

100 Access Network
102 Base Station
102' Small Cell
104UE
110 Geographic Coverage Areas
110' Coverage Area
120 Communication Links
132 backhaul links
134 backhaul links
150 Wi-Fi access points (AP)
152 Wi-Fi stations (STA)
154 Communication Links
158 Device-to-Device (D2D) Communication Links
160 Evolved Packet Core (EPC)
162 Mobility Management Entity (MME)
164 MME
166 Serving Gateway
168 Multimedia Broadcast Multicast Service (MBMS) Gateway
170 Broadcast Multicast Service Center (BM-SC)
172 Packet Data Network (PDN) Gateway
174 Home Subscriber Server (HSS)
176 Internet Protocol (IP) Services
180g Node B (gNB)
182 Beamforming
182' Sending direction
182'' receiving direction
184 backhaul links
190 Core Network
192 Access and Mobility Management Function (AMF)
193 AMF
194 Session Management Facility (SMF)
195 User Plane Function (UPF)
196 Unified Data Management (UDM)
197 IP Services
198 Contention Window (CW) Components
199 CW Component
200 Figures
230 Figure
250 Figures
280 Figures
310 Base Station
316 Transmit (TX) Processor
318 Transmitter
320 Antenna
350UE
352 Antenna
354 Receiver
356 Receive (RX) Processor
358 Channel Estimator
359 Controller/Processor
360 Memory
368 Transmit (TX) Processor
370 Receive (RX) Processor
374 Channel Estimator
375 Controller/Processor
376 Memory
400 Call Flow
402UE
404 Base Station
410 Uplink (UL) transmission
412 CW size adjustment technique
414 ACK/NACK
418 CW size adjustment technique
420 Downlink (DL) Transmission
422 CW size adjustment technique
424 ACK/NACK
428 CW size adjustment technique
500 Techniques
504 Reference Duration (RD) Determination Component
506RD
508 SCS Slave RD Generator
509 Technique
510 Technique
511 Technique
512 Technique
514 Slot-Based RD Decision Method
515 Symbol-Based RD Decision Method
516 Puncturing Techniques
518 Symbol-Based RD Decision Method
520 Criteria Sending Decision Component
524 Reference Transmission
526 Direct determination of reference transmission
528 Reference transmission is determined after RD is determined
534 CW Tuning Components
536 Explicit Feedback
538 Implicit Feedback
542 CW size
604 slot size
610RD
614RD
640RD
644 symbol size
Example of 1000 times/symbols
1014 times/symbols
1016 1st Slot
1100 Transmit/Receive Switching Example
1600 Conceptual Data Flow Diagram
1602 Equipment
1602' Equipment
1604 Receiving Component
1606 Uplink-centric Transmission Opportunity (TxOP) Processing Component
1610 Transmission Component
1612 RD Decision Component
1613RD
1614 Criteria Sending Decision Component
1615 Reference Transmission
1616 CW Tuning Component
1617 Adjusted CW
TxOP with 1640 UL and DL Tx processing components
1650 Devices
1700 Figures
1704 Processing System
1706 Computer-readable medium/memory
1710 Transceiver
1714 Processing System
1720 Antenna
1724 Bus
1800 Conceptual Data Flow Diagram
1802 Equipment
1802' Equipment
1804 Receiving Component
1806 UL and DL transmission processing components
1810 Transmission Component
1812 Reference duration determination component
1814 Criteria Sending Decision Component
1816 CW Tuning Component
1850 Base Station
1900 Figure
1904 Processor
1906 Computer-readable medium/memory
1910 Transceiver
1914 Processing System
1920 Antenna
1924 Bus

Claims (13)

1. An apparatus for wireless communication in a wireless device, comprising:
Memory,
at least one processor coupled to the memory,
determining a reference duration of a channel occupation time (COT), the reference duration being based at least in part on a subcarrier spacing (SCS) , reception of a physical downlink shared channel (PDSCH) transmission, and a first slot in which all shared channel transmissions are not punctured ;
updating a contention window (CW) based at least in part on receiving the PDSCH transmission during the reference duration ;
and at least one processor configured to:
Device. The PDSCH transmission is a non-punctured PDSCH transmission,
The apparatus of claim 1 , in particular, the reference duration comprises a slot including the non-punctured PDSCH transmission or an end of the non-punctured PDSCH transmission. The reference duration is determined based on the PDSCH transmission starting within a predetermined number of symbols or a predetermined time from the beginning of a slot.
2. The apparatus of claim 1. Updating the CW includes one of: increasing the CW based at least in part on a negative acknowledgment received by the wireless device for the PDSCH transmission; or assigning a predetermined minimum value (CW_min) to the CW based at least in part on an acknowledgment received by the wireless device for the PDSCH transmission; or
Updating the CW includes increasing the CW based at least in part on no acknowledgment being received by the wireless device for the PDSCH transmission.
2. The apparatus of claim 1. 2. The apparatus of claim 1, wherein the wireless device determines a first reference duration for a first SCS and a second reference duration for a second SCS, and the wireless device updates the CW based on a first shared channel transmission based on the first SCS during the first reference duration and a second shared channel transmission based on the second SCS during the second reference duration. the memory and the at least one processor;
and determining the at least one reference PDSCH transmission based on a control channel transmission for at least one reference PDSCH transmission transmitted within a predetermined amount of time or a predetermined number of symbols from a start of the COT;
In particular, the at least one reference PDSCH transmission comprises:
the at least one reference PDSCH transmission starting within the reference duration;
the at least one reference PDSCH transmission ending within the reference duration;
at least one Code Block Group (CBG) of said at least one reference PDSCH transmission that at least partially overlaps with said reference duration; or
the at least one reference PDSCH transmission having the control channel transmission during the reference duration;
The apparatus of claim 1 , wherein the determination is based on at least one of: The reference duration or reference PDSCH transmission is determined based on whether the PDSCH transmission includes a broadcast without feedback, and the CW is updated based on the reference PDSCH transmission determined by the wireless device.
2. The apparatus of claim 1. the reference duration is determined further based on whether at least one non-punctured code block group (CBG) is transmitted during the reference duration, and the reference duration is extended when no non-punctured shared channel transmission or no non-punctured CBG is transmitted during the reference duration.
2. The apparatus of claim 1. The reference duration is
a second slot including at least one non-punctured shared channel transmission; or
The third slot in which at least one shared channel CBG is not punctured
Based on non-punctured slots that contain at least one of
2. The apparatus of claim 1. The reference duration is extended to include multiple slots including punctured shared channel transmissions and one slot including at least one non-punctured shared channel transmission or a non-punctured CBG.
2. The apparatus of claim 1. 2. The apparatus of claim 1, wherein a plurality of slots include punctured transmissions, and the reference duration is determined to include one slot including at least one non-punctured shared channel transmission or a non-punctured CBG and at least one of the plurality of slots including a punctured downlink transmission. 1. A method for wireless communication in a wireless device, comprising:
determining a reference duration of a channel occupation time (COT), the reference duration being based at least in part on a subcarrier spacing (SCS), reception of a physical downlink shared channel (PDSCH) transmission, and a first slot in which all shared channel transmissions are not punctured ;
updating a contention window (CW) based at least in part on receiving the PDSCH transmission during the reference duration;
A method comprising: A computer program comprising instructions which, when executed on a processor, cause the processor to perform the method of claim 12 .

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