Systems and methods for joint access to unlicensed spectrum

Abstract

A method and apparatus for a transmission-reception point (TRP) jointly accessing one or more unlicensed channels in unlicensed spectrum with at least one other TRP. A step of aligning a start time of a potential transmission on at least one of the one or more unlicensed channels with a start time of a potential transmission on the at least one of the one or more unlicensed channels by at least one other TRP. A further step includes performing channel access on the at least one of the one or more unlicensed channels by performing a spatial domain channel access procedure, and / or, a combination of a spatial domain channel access procedure and a frequency domain multi-channel access procedure. Another step includes transmitting on the at least one of the one or more unlicensed channels at the aligned start time in a jointly accessed time period when the at least one of the one or more unlicensed channels is available.

Description

[0001] This application is a divisional application. The original application has the application number 201980012216.0 and the original application date is June 11, 2019. The entire contents of the original application are incorporated herein by reference.

[0002] Cross-references

[0003] This application claims priority to U.S. Patent Application No. 16 / 005,564, filed June 11, 2018, entitled “System and Method for Joint Access to Unauthorized Spectrum,” the entire contents of which are incorporated herein by reference. Technical Field

[0004] This application relates to mobile air interface technology, and more particularly to systems and methods for transmit receive points (TRPs) to access unlicensed spectrum. Background Technology

[0005] There has been ongoing interest in increasing the use of unlicensed spectrum. Aggregating unlicensed spectrum into licensed spectrum is particularly interesting to augment network resources when needed. Licensed Assisted Access (LAA) allows access to unlicensed spectrum via unlicensed component carriers, assisted by a primary component carrier (PCC) operating on licensed spectrum. LAA aims to migrate the mobile broadband (MBB) air interface to unlicensed spectrum by aggregating unlicensed component carriers (CCs) within an operator's cell. Small cells (also known as low-power nodes (LPNs)) are low-power radio access nodes that can operate in both licensed and unlicensed spectrum and have a relatively short coverage range (e.g., within 200 meters of the small cell's antenna). The 5 GHz unlicensed spectrum, typically used by wireless local area networks (WLANs), is of particular interest.

[0006] Some existing technologies send blanking signals or use a delay period between the completion time of the clear channel assessment (CCA) process and the start time of downlink transmission, and do not use unlicensed spectrum for downlink transmission during this period. Similarly, other TRPs or other LAA groups in the WLAN can start downlink transmission during the delay period, causing downlink transmission conflicts. Furthermore, some existing technologies have aggressive schemes for accessing unlicensed spectrum.

[0007] LAA is for a separate TRP that accesses one or more channels and does not support space reuse.

[0008] For the technology, accessing unlicensed spectrum in a fair and efficient manner is crucial for achieving satisfactory intra- or inter-carrier coexistence performance, as well as satisfactory coexistence with existing WLANs. Achieving coexistence fairness is more challenging with the anticipated dense deployment and / or high channel occupancy of WLANs, such as IEEE 802.11ac and LAA networks. New radio unlicensed (NR-U) networks are being developed to address these issues to some extent. Summary of the Invention

[0009] This disclosure describes methods and systems for accessing unlicensed spectrum through a set of transmit / receive points (TRPs). A set of TRPs may include any one of a group of base stations (e.g., gNBs) spatially distributed with ideal or non-ideal backhaul / fronthaul connections, a set of antenna panels (in-site panels) of the same gNB, or a set of antennas with different QCL (quasi-co-location) assumptions, i.e., different large-scale channel parameters. Thus, a single TRP may be a gNB, a radio head, an antenna set of a gNB, or one of multiple antenna sets with different QCL assumptions.

[0010] The purpose of embodiments of this disclosure is to access unlicensed spectrum in an efficient manner. In embodiments of this application, optional objectives may also include avoiding downlink transmission conflicts, improving coexistence fairness with other wireless access technologies, and implementing advanced transmission schemes such as coordinated multi-point transmission (CoMP) in unlicensed spectrum.

[0011] According to one aspect of this application, a method is provided for a Transmitting Receiver Point (TRP) to jointly access one or more unlicensed channels in an unlicensed spectrum with at least one other TRP. The method includes: aligning the start time of a potential transmission on at least one of the one or more unlicensed channels with the start time of a potential transmission on at least one other TRP on the at least one of the one or more unlicensed channels; performing channel access on the at least one of the one or more unlicensed channels by performing a spatial domain channel access procedure, and / or a combination of a spatial domain channel access procedure and a frequency domain multichannel access procedure; and, when the at least one of the one or more unlicensed channels is available, transmitting on the at least one of the one or more unlicensed channels at the aligned start time during a joint access period.

[0012] In some embodiments, the method further includes receiving configuration from a central controller, the configuration including indications of the type of spatial domain channel access procedure and the type of frequency domain multichannel access procedure for jointly accessing the one or more unauthorized channels.

[0013] In some embodiments, performing channel access includes performing the first type of CCA on at least one of the one or more unlicensed channels by configuring a random backoff counter for at least one unlicensed channel for the TRP to perform a first type of free channel assessment (CCA).

[0014] In some embodiments, configuring a random backoff counter for at least one unlicensed channel of a first type CCA for the TRP includes configuring a random backoff counter for one of the unlicensed channels that is different from the at least one other TRP.

[0015] In some embodiments, configuring a random backoff counter for at least one unlicensed channel of a first type CCA for the TRP includes configuring a random backoff counter for the TRP that is the same as that for the at least one other TRP for one of the unlicensed channels.

[0016] In some embodiments, the random backoff counter is generated based at least in part on a single distribution for a contention window, according to a channel access priority level.

[0017] In some embodiments, the random backoff counter is generated based on the distribution of the contention window, the contention window corresponding to the maximum channel access priority level value of all unlicensed channels in the set of the TRP and the at least one other TRP.

[0018] In some embodiments, configuring a random backoff counter for at least one unlicensed channel of the first type CCA for the TRP includes configuring the TRP with the same random backoff counter for all the unlicensed channels as the at least one other TRP.

[0019] In some embodiments, configuring a random backoff counter for at least one unlicensed channel of the first type CCA for the TRP includes configuring the TRP with the same random backoff counter for all the unlicensed channels as the at least one other TRP.

[0020] In some embodiments, performing the first type of CCA on at least one of the one or more unlicensed channels includes performing wideband (WB) CCA on all of the unlicensed channels simultaneously.

[0021] In some embodiments, the method further includes, when the TRP determines that the WB channel is busy during the CCA time slot of the WB CCA, switching from performing the WB CCA to performing the subband CCA for the remaining CCA time slots without terminating the channel access procedure for each individual unlicensed channel.

[0022] In some embodiments, determining that the WB channel is busy during the CCA time slot of the WB CCA includes receiving a notification of CCA failure.

[0023] In some embodiments, the method further includes the TRP performing a second type of CCA on at least one of the one or more unlicensed channels prior to the start time of the potential transmission on the one or more unlicensed channels.

[0024] In some embodiments, the method further includes: when the first type CCA or the second type CCA senses that the unlicensed channel is busy during the CCA time slot, the TRP sends a notification to the at least one other TRP of at least one of the CCA failure and the missed start time of the potential transmission.

[0025] In some embodiments, the method further includes: receiving a notification of a potential transmission start time that is earlier than the start time of a previously scheduled potential transmission, and accordingly re-aligning the start times of the potential transmission.

[0026] In some embodiments, the duration between the end of the first type of CCA and the start time of the potential transmission is defined by at least one of the self-delay period, the post-back-off CCA, and the duration of the second type of CCA.

[0027] According to one aspect of this application, a transmit-receive point (TRP) is provided, comprising: at least one antenna configured to transmit or receive signals and a controller. The controller is configured to: align the start time of a potential transmission on at least one of the one or more unlicensed channels with the start time of a potential transmission on at least one other TRP on the at least one of the one or more unlicensed channels; perform channel access on the at least one of the one or more unlicensed channels by performing a spatial domain channel access procedure, and / or a combination of a spatial domain channel access procedure and a frequency domain multichannel access procedure; and, when the at least one of the one or more unlicensed channels is available, transmit on the at least one of the one or more unlicensed channels at the aligned start time during a joint access period.

[0028] In some embodiments, the controller is further configured to receive configuration from a central controller on at least one antenna, the configuration including indications of the type of spatial domain channel access procedure and the type of frequency domain multichannel access procedure for joint access to the one or more unlicensed channels.

[0029] In some embodiments, the controller is configured to perform channel access by performing the first type of CCA on at least one of the one or more unlicensed channels by configuring a random backoff counter for at least one unlicensed channel for the TRP to perform a first type of free channel assessment (CCA).

[0030] In some embodiments, the controller configuring a random backoff counter for at least one unlicensed channel of a first type CCA for the TRP includes configuring a random backoff counter for one of the unlicensed channels that is different from the at least one other TRP.

[0031] In some embodiments, configuring a random backoff counter for at least one unlicensed channel of a first type CCA for the TRP includes configuring a random backoff counter for the TRP that is the same as that for the at least one other TRP for one of the unlicensed channels.

[0032] In some embodiments, the controller performing the first type of CCA on at least one of the one or more unlicensed channels includes simultaneously performing wideband (WB) CCA on all of the unlicensed channels.

[0033] In some embodiments, the controller is further configured to, when the TRP determines that the WB channel is busy during the CCA slot of the WBCCA, switch from performing the WB CCA to performing the subband CCA for the remaining CCA slots without terminating the channel access procedure for each individual unlicensed channel.

[0034] In some embodiments, the controller is further configured to perform a second type of CCA on at least one of the one or more unlicensed channels prior to the start time of the potential transmission on the one or more unlicensed channels.

[0035] In some embodiments, when the first type CCA or the second type CCA senses an unlicensed channel busy during a CCA time slot, the controller is also configured to send a notification to the at least one other TRP of at least one of a CCA failure and a missed start time for a potential transmission. Attached Figure Description

[0036] Reference will now be made to the accompanying drawings, which illustrate exemplary embodiments of this application, and wherein:

[0037] Figure 1 This is a block diagram illustrating an example communication system according to one implementation of the present disclosure;

[0038] Figure 2 This is a block diagram illustrating an example processing system according to one implementation of the present disclosure;

[0039] Figure 3A This is a diagram illustrating the mechanism by which a single new radio unlicensed (NR-U) gNB accesses unlicensed spectrum;

[0040] Figure 3B This is a diagram illustrating a set of mechanisms by which NR-UgNBs access unlicensed spectrum;

[0041] Figure 4 This is a diagram illustrating an example of a set of TRPs attempting to jointly access a single channel in unlicensed spectrum according to an embodiment of this disclosure;

[0042] Figure 5 This is a diagram illustrating a second example of a group of TRPs attempting to jointly access a single channel in unlicensed spectrum according to an embodiment of this disclosure;

[0043] Figure 6A This is a diagram illustrating a third example of a set of TRPs attempting to jointly access a single channel in unlicensed spectrum according to an embodiment of this disclosure;

[0044] Figure 6B This is a diagram illustrating a fourth example of a set of TRPs attempting to jointly access a single channel in unlicensed spectrum according to an embodiment of this disclosure;

[0045] Figure 7A This is a diagram illustrating a fifth example of a group of TRPs attempting to jointly access a single channel in unlicensed spectrum according to an embodiment of this disclosure;

[0046] Figure 7B This is a diagram illustrating a sixth example of a group of TRPs attempting to jointly access a single channel in unlicensed spectrum according to an embodiment of this disclosure;

[0047] Figure 8A This is a diagram illustrating a seventh example of a set of TRPs attempting to jointly access a single channel in unlicensed spectrum according to an embodiment of this disclosure;

[0048] Figure 8B This is a diagram illustrating an eighth example of a set of TRPs attempting to jointly access a single channel in unlicensed spectrum according to an embodiment of this disclosure;

[0049] Figure 9A This is a diagram illustrating a first example of a set of TRPs attempting to jointly access multiple channels in unlicensed spectrum according to an embodiment of this disclosure;

[0050] Figure 9B This is a diagram illustrating a second example of a set of TRPs attempting to jointly access multiple channels in unlicensed spectrum according to an embodiment of this disclosure;

[0051] Figure 10A This is a diagram illustrating a third example of a set of TRPs attempting to jointly access multiple channels in unlicensed spectrum according to an embodiment of this disclosure;

[0052] Figure 10B This is a diagram illustrating a fourth example of a set of TRPs attempting to jointly access multiple channels in unlicensed spectrum according to an embodiment of this disclosure;

[0053] Figure 10C This is a diagram illustrating a fifth example of a set of TRPs attempting to jointly access multiple channels in unlicensed spectrum according to an embodiment of this disclosure;

[0054] Figure 11A This is a diagram illustrating a sixth example of a set of TRPs attempting to jointly access multiple channels in unlicensed spectrum according to an embodiment of this disclosure;

[0055] Figure 11B This is a diagram illustrating a seventh example of a set of TRPs attempting to jointly access multiple channels in unlicensed spectrum according to an embodiment of this disclosure;

[0056] Figure 12 This is a diagram illustrating an eighth example of a set of TRPs that attempt to simultaneously access a single channel while jointly accessing multiple channels in unlicensed spectrum, according to an embodiment of the present disclosure;

[0057] Figure 13 This is a flowchart describing the method according to the first aspect of this application;

[0058] Figure 14 This is a flowchart describing the method according to the second aspect of this application; and

[0059] Figure 15 This is a flowchart describing the method according to the third aspect of this application.

[0060] Similar reference numerals may be used in the accompanying drawings to denote similar parts. Although various aspects of the invention will be described in conjunction with the illustrated embodiments, it should be understood that the invention is not intended to be limited to these embodiments. Detailed Implementation

[0061] This disclosure teaches methods and systems for accessing unlicensed spectrum. Although the following description pertains primarily to New Radio Unlicensed (NR-U) networks, this disclosure can also be applied to other networks operating on unlicensed spectrum.

[0062] Unlicensed spectrum can be accessed using a listen-before-talk (LBT) mechanism. The TRP can access the medium (unlicensed spectrum in this application) to transmit its downlink transmissions when the TRP senses that the medium is available or idle for a predefined period, such as a downlink burst during channel occupancy time (COT). Such a period might be a free channel assessment (CCA) period. Downlink transmissions such as downlink COT can include downlink user data and / or control signaling. Downlink COT can also include UL data and / or control signaling occurring after the DL to UL handover time gap.

[0063] The LBT mechanism specified for LAA (3GPP standards versions 13-15) relies solely on energy detection (ED) to determine media availability, and it is considered the baseline for designing channel access mechanisms for NR-U. Using the same ED threshold, this LBT mechanism is more aggressive than the carrier sense multiple access with collision avoidance (CSMA / CA) mechanism currently used in WLANs. This is because the CSMA / CA mechanism used by WLANs can be 20 dB more sensitive to detecting the presence of other WLAN signals through physical carrier sense and MAC (virtual) carrier sense.

[0064] Similarly, joint access by NR-U TRPs is expected to simplify NR-U interference measurement and management. In particular, joint access by NR-U TRPs can help address the "exposed node" problem within NR-U networks, potentially leading to improved spectrum efficiency. The "exposed node" problem occurs when two adjacent NR-U TRPs operate independently, where one can still block the other's access to the medium, even though they do not interfere with each other. When two TRPs do not interfere with each other's transmissions, the UEs they serve are outside the overlapping coverage area. The medium can be unlicensed spectrum, unlicensed spectrum channels, or sets of unlicensed spectrum channels. When another TRP senses a TRP's transmission on the medium, it can perceive that the medium is busy. When a TRP perceives the medium as busy, it considers the medium unavailable at its scheduled downlink transmission start time. When two TRPs are grouped together, for example, in the same group or radio access cluster (RAC), the TRPs can jointly access the medium as a group. This TRP group can access the medium synchronously at the same start time. The first TRP will not prevent the second TRP from accessing the medium because the second TRP has already started transmitting through the medium.

[0065] Joint access by NR-U TRPs can also provide more effective protection against co-channel interference caused by the "hidden node" problem. The "hidden node" problem occurs when a node within the coverage area of ​​a first NR-U TRP may not be within the coverage area of ​​an adjacent second NR-U TRP. However, the node can still interfere with the transmission of the second TRP. By combining the first and second TRPs together as a single group or RAC, transmissions from the first TRP can block channel access by nodes, thus protecting the transmission of the first TRP.

[0066] Joint access to adjacent TRPs can also enable features such as aligning transmissions of adjacent TRPs to allow coexisting nodes more talk time, thereby improving coexistence fairness and enabling advanced transmission schemes such as Coordinated Multipoint (CoMP).

[0067] Figure 1 An example system 100 is shown, in which the examples described herein can be implemented. System 100 can be used in an NR-U network.

[0068] In example system 100, a controller manages multiple TRP groups, such as the operation of RACs, for example, TRP groups 140, 150, and 160. In an embodiment, the controller may be a central spectrum management control unit (CSMC) 102. CSMC 102 is a network logic controller that may be hosted by a macro gNB or a TRP connected to a TRP in the same group. CSMC 102 may define one or more RACs for the TRPs managed by CSMC 102. Each RAC may be channel-specific or channel set-specific—that is, each RAC may be defined as using unlicensed spectrum channels or a different set of unlicensed channels than adjacent RACs. Several examples of mechanisms for grouping TRPs into disjoint groups or RACs are described in U.S. Application 14 / 869,617, which is incorporated herein by reference.

[0069] Each group or RAC can include one or more TRPs, and each TRP can belong to one or more groups or RACs. For example, Figure 1 TRP 108 belongs to both Group 140 and Group 150. Each TRP provides access to unlicensed spectrum for one or more devices, such as UEs or STAs. A TRP can also be a gNB. Figure 1 In the example, TRP group 140 may include TRP1 104, TRP2 106 and TRP3 108; TRP group 150 may include TRP3 108 and TRP6 110; and TRP group 160 may include TRP4 112 and TRP5 114.

[0070] Each TRP in a TRP group can be connected to the CSMC 102 via at least one communication link, such as a backhaul link like backhaul links 124, 126, 128, 130, 132, or 134. Messages can be exchanged between the TRP and the CSMC 102 via the communication link. The communication link can be a wireless communication link, such as a microwave link, or a wired link, such as a fiber optic link. The CSMC 102 can manage the TRPs via one or more communication links.

[0071] The expectation is that joint access of TRPs, including NR-U TRPs, will timely achieve a frequency reuse factor of 1. As shown in TRP groups 140, 150, and 160, TRP group 140 can use unlicensed spectrum channel 1, TRP group 150 can use unlicensed spectrum channel 2, and TRP group 160, whose coverage area does not overlap with that of TRP group 140, can reuse unlicensed spectrum channel 1. Grouping TRPs allows all TRPs in a TRP group to use the same unlicensed channel. This allows for a frequency reuse factor for one TRP within a TRP group. For TRPs belonging to more than one TRP group, when a TRP operates as a member of a TRP group, it uses the unlicensed spectrum channel allocated to that specific TRP group. For example, when... Figure 1 When TRP3 108 operates as a member of TRP group 140, TRP3 108 uses the unlicensed channel allocated to TRP group 140, i.e., unlicensed channel 1; when TRP108 operates as a member of TRP group 150, TRP3 108 uses the unlicensed spectrum channel allocated to group 150, i.e., unlicensed spectrum channel 2.

[0072] although Figure 1 Only one CSMC 102 is shown, but multiple CSMCs can be used to manage multiple TRPs. CSMCs can be interconnected via backhaul links or interfaces, such as X2 or 5G Xn. Similarly, the number of TRPs in each TRP group managed by CSMC 102 can also vary.

[0073] Figure 2 This is a block diagram of an example processing system 200, which can be used to implement the methods and systems disclosed herein. Processing system 200 can be a component of CSMC, gNB, or TRP. Other processing systems suitable for implementing this disclosure can also be used, which may include components different from those discussed below. Although Figure 2 A single instance of each component is shown, but multiple instances of each component may exist in the processing system 200.

[0074] Processing system 200 may include one or more processing devices 205, such as processors, microprocessors, application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), special-purpose logic circuits, or combinations thereof. Processing system 200 may also include one or more input / output (I / O) interfaces 210 for interacting with one or more suitable input devices 235 and / or output devices 240. Processing system 200 may include one or more network interfaces 215 for wired or wireless communication with a network (e.g., a wireless core network, intranet, Internet, P2P network, WAN, and / or LAN). Network interface 215 may include wired links (e.g., Ethernet cable or fiber optic links) and / or wireless links (e.g., one or more microwave links or satellite links) for intra-network and / or inter-network communication. For example, network interface 215 may provide wireless communication via one or more transmitters or transmitting antennas and one or more receivers or receiving antennas. The processing system 200 may also include one or more storage units 220, which may include mass storage units such as solid-state drives, hard disk drives, disk drives and / or optical disk drives.

[0075] Processing system 200 may include one or more memories 225, which may include volatile or non-volatile memories (e.g., flash memory, random access memory (RAM), and / or read-only memory (ROM)). Non-transitory memories 225 may store instructions for execution by processing device 205, such as executing the examples described herein. Memory 225 may include other software instructions, such as those for implementing an operating system and other applications / functions. In some examples, one or more datasets and / or modules may be provided by external memory (e.g., an external drive that communicates with processing system 200 via wired or wireless communication) or by temporary or non-transitory computer-readable media. Examples of non-transitory computer-readable media include RAM, ROM, erasable programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), flash memory, compact disc ROM (CD-ROM), or other portable memory storage.

[0076] A bus 230 may exist to provide communication between components of the processing system 200, including processing device 205, I / O interface 210, network interface 215, storage unit 220, and / or memory 225. Bus 230 may be any suitable bus architecture, including, for example, a memory bus, peripheral bus, or video bus.

[0077] exist Figure 2 In this embodiment, input devices 235 (e.g., keyboard, mouse, microphone, touchscreen, and / or keypad) and output devices 240 (e.g., display, speaker, and / or printer) are shown as being external to the processing system 200. In other examples, one or more of the input devices 235 and / or output devices 240 may be included as components of the processing system 200.

[0078] Figure 3A The Category 4 (CAT4) LBT mechanism for accessing a single NR-U gNB media is illustrated. Figure 3A In this context, the TRP group is associated with CSMC 302 and NR-U gNB1 304. CSMC 302 is connected to gNB1 304 via a backhaul link. gNB1 304 can provide unlicensed spectrum access to NR-U UE1 and NR-U UE2. Figure 3A The horizontal axis of the diagram is divided into intervals marked 1 to 8. These marked intervals represent the boundaries of specific time units. A time unit can be a time slot, a micro-time slot, or a subframe boundary. The boundary can also be aligned with the boundaries of time units in the licensed spectrum. In this example, gNB1 304 first uses, for example, energy detection (ED)-based CCA to sense that the medium is busy during time period 312, which occurs in a portion of interval 1, all of interval 2, and a portion of interval 3. The CCA process includes a Distributed Coordination Function (DCF) InterFrame Space (DIFS) 314 within interval 3 and a random contention window (CW) duration 316 occurring in a portion of interval 3, all of interval 4, and a portion of interval 5. CW 316 is also known as the extended Clear Channel Assessment (eCCA) process. gNB1 304 independently generates the random backoff counter value CW. p This corresponds to CW 316, where CW = CW p×CCA slot duration. For example, the CCA slot duration can be 9 μs. When the medium remains idle for the duration DIFS 314, for example, 34 μs, gNB1 304 continues to sense the medium during CW 316. When NR-U gNB1 304 senses the medium during CW 316, it initializes to CW after the idle CCA slot duration has elapsed. p The backoff counter value is decremented by 1 and decreases to 0 at the completion time of CW 316. Figure 3A During the completion time of CW316, the medium remains idle. 3GPP Release 13 requires LAA TRPs to align their respective downlink burst transmissions with the start time of the licensed primary component carrier subframe or licensed spectrum subframe during COT, such as the licensed subframe start time. However, for NR-U, there is no requirement to align transmissions with the start time of the licensed primary component carrier subframe. CSMC 302 determines the downlink burst transmission start time 320 and transmits it to NR-U gNB1 304 via the backhaul link, allowing NR-U gNB1 304 to access the medium at start time 320. At start time 320, aligned with the start time of the licensed primary component carrier subframe, gNB1 304 begins transmitting its downlink burst to NR-U UE1 and / or NR-U UE2 via the medium for the duration of 322.

[0079] If the eCCA process is terminated during CW 316 due to a media "busy" assessment, the remaining backoff counter values ​​are frozen to maintain priority in subsequent media access attempts by the NR-U gNB1 304. In a specific example, the CW initially generated during CW 316 by the random backoff counter generator of the NR-U gNB1 304... p The value is equal to 5 CCA slot durations. If the medium becomes busy when the backoff counter value is currently equal to 3 CCA slot durations (i.e., after the counter has decreased by 2 successful CCA slot durations), the random backoff counter of the NR-U gNB1 304 is frozen for 3 CCA slot durations. In subsequent media access attempts of the NR-U gNB1 304, the random backoff counter generator will not generate a new counter value, but will use the remaining value of 3 CCA slot durations.

[0080] Figure 3B A CAT4 LBT mechanism for a set of NR-UgNB joint access media is shown. Figure 3BIn the example, the TRP group is associated with CSMC 306, NR-U gNB1 308, and NR-U gNB2 310. CSMC 306 is connected to each of NR-U gNB1 308 and NR-U gNB2 310 via a backhaul link. NR-U gNB1 308 can provide unlicensed spectrum access to NR-U UE1 and NR-U UE2. NR-U gNB1 310 can provide unlicensed spectrum access to NR-U UE3. Figure 3B In this process, NR-U gNB1 308 and NR-U gNB2 310 can first use, for example, ED-based CCA to sense the medium during busy periods 332 and 342, respectively. NR-U gNB1 308 and NR-U gNB2 310 maintain sensing of the medium. NR-U gNB1 308 and NR-U gNB2 310 independently generate corresponding random backoff counter values ​​CW. p 1 and CW p 2, which correspond to CW1 336 and CW2 346 respectively, where CW1 = cws1 × CCA time slot duration and CW2 = cws2 × CCA time slot duration. For example, the CCA time slot duration can be 9 μs. When the medium remains idle for DIFS duration 334 or 344, NR-U gNB1 308 and NR-UeNB2 310 continue to sense the medium during CW 336 and CW 346. When NR-U gNB1 308 and NR-U gNB2 310 sense the medium during the corresponding CW1 336 and CW2 346, the corresponding backoff counter values ​​cws1 and cws2 are decremented by 1 when the CCA time slot duration has elapsed, and decrease to 0 at the completion time of CW 336 or CW 346 respectively. Similarly, if the CCA process terminates due to a media “busy” assessment during CW1336 or CW2 346, the remaining backoff counter values ​​cws1 or cw2 are frozen to maintain priority in subsequent media access attempts for NR-U gNB1 308 or NR-U gNB2 310.

[0081] CW1 336 and CW2 346 can be different from each other. Figure 3BIn the example, CW1 336 is shorter than CW2 346. NR-U gNB1 308 and NR-U gNB2 310 continuously assess whether the medium is idle during CW1 336 and CW2 346, respectively, using ED-based CCA. NR-U gNB1 308 can align its downlink burst transmission with the start time of the licensed primary component carrier subframe at 321, after both CW1 period 336 and CW2 period 346 have been completed. Therefore, after a successful CCA period, each of NR-U gNB1 308 and NR-U gNB2 310 postpones its downlink burst transmission to a common start time 321, so that gNB1 308 and gNB2 310 can jointly access the medium at the common downlink subframe transmission start time 321. CSMC 306 determines the common start time 321 and transmits it to NR-U gNB1 308 and NR-U gNB2 310 via the corresponding backhaul link. After the CCA procedure is successfully completed, but before the start time 321, NR-U gNB1 308 invokes a delay period 338 to align its downlink burst transmission with the start time 321. Similarly, NR-U gNB2 310 invokes a delay period 348 to align its burst transmission starting at the start time 321. Thus, NR-U gNB1 308 and NR-U gNB2 310 can jointly access the medium at the common start time 321.

[0082] Similar to Figure 3A The example of NR-U gNB1 304 in Figure 3B If eCCA terminates due to a “busy” assessment during the CW1 336 or CW2 346 period, the remaining backoff counter value cws1 of NR-U gNB1 308 or cws2 of NR-U gNB2310 is frozen to maintain priority in subsequent access attempts.

[0083] During the delay periods 338 and 348, neither NR-U gNB1 308 nor NR-U gNB2 310 sends any signal to notify neighboring TRPs of other networks that either NR-U gNB1 308 or NR-U gNB2 310 has completed the CCA procedure. Therefore, the medium appears to remain idle for other network TRPs, such as WLANs or other NR-U networks. Just before the end of the delay periods 338 and 348, Category 2 (CAT2) CCA 339, 349 can be performed to determine if the channel is still accessible. CAT2 CCA is a short, single-trigger CCA that ends at the target start time to access the channel. After the delay periods 338 and 348, if the CAT2 CCA is successful, NR-U gNB1 308 and NR-U gNB2 310 send the corresponding downlink bursts in the COT to the NR-U UE, respectively, starting at the common start time 321 of durations 340 and 350.

[0084] exist Figure 3A In the example, the NR-U gNB1 304 sends a blanking signal 318 on the medium to prevent TRP access to the medium by WLAN or other NR-U groups. However, in Figure 3B In the group access mechanism, Figure 3B NR-U gNB1 308 or NR-U gNB2 in the NR-U group cannot send empty blanking or reserved signals during delay periods 338 or 348 to prevent TRP access to the medium by WLAN or other NR-U groups. Figure 3B In this scenario, after NR-U gNB1 308 completes its CCA process but before NR-U gNB2 310 completes its CCA process, if NR-U gNB1 308 begins sending a blanking signal on the medium, and if NR-U gNB2 310 senses the blanking signal, then NR-U gNB2 310 can determine that the medium has become "busy" and subsequently terminate its eCCA process. Therefore, the blanking signal may disrupt joint access to the medium by a set of TRPs.

[0085] On the other hand, because the medium remains idle during delay periods 338 and 348, adjacent TRPs of WLANs or other NR-U groups that have completed their CCA process before Common Start Time 321 can access the medium. In other words, the medium's state can change from idle to busy during delay periods 338 and 348. Access to the medium by adjacent TRPs of WLANs or other NR-U groups before Start Time 321 will not cause NR-U gNB1 308 and NR-U gNB2 310 to back off downlink burst transmissions in COT at Common Start Time 321. Thus, when NR-U gNB1 308 and NR-U gNB2 310 begin transmitting COT bursts on the downlink of the medium at Common Start Time 321, their downlink burst transmissions in COT conflict with the transmissions of adjacent TRPs of WLANs or other NR-U groups. This conflict can lead to backoff delays and throughput losses for other coexisting networks, especially WLANs.

[0086] Alternatives to CAT4 CCA, or other versions of CCA besides CAT4 CCA, can be used. CAT2 CCA involves a predefined deterministic duration, such as a short, single-trigger CCA of 25 or 34 μs, which is exactly the predetermined t of the channel accessing the downlink or uplink. target Before that time. Besides CAT4 CCA, CAT2 CCA can also be used. For example, CAT4 CCA might last for a period of time, followed by CAT4 CCA and t. target Self-delay between times. To determine whether there have been any new transmissions on the channel since the end of CAT4 CCA, or whether the transmissions on the channel determined during CAT4 CCA have passed, at t target The CAT2 CCA that occurs before the time limit serves as a final check to determine channel accessibility. Another type of CCA is Wideband (WB) CCA. Although CAT4 CCA and CAT2 CCA were originally defined for single-channel CCA, WB CCA extends the CCA concept to allow the TRP to simultaneously determine the set state of multiple consecutive channels. In some embodiments of this disclosure, if the WB channel state is determined to be busy, the WB CCA can, for example, switch to multiple sub-band CCAs during the backoff duration CCA. The execution of sub-band CCAs is similar to that of the original CAT4 CCA or CAT2 CCA.

[0087] A LAA-specific channel access procedure is used to perform multi-carrier transmissions on a single TRP, according to one of the Type A or Type B procedures defined in Section 15.1.5 of 3GPP TS 36.213. Depending on the Type A or Type B procedure, the TRP can access multiple component carriers (CCs) or channels performing NR-U secondary cell (Scell) transmissions. In LAA, each CC is a 20MHz unlicensed channel. In NR-U, a CC can include multiple channels. However, similar frequency-domain procedures, such as Type A and Type B procedures, can be applied within a single CC.

[0088] Type A has two variants for generating multiple backoff counters for a set of CCs accessible to the TRP. In the first variant, known as Type A1, a backoff counter for each CC in a set is generated and maintained independently of the different distributions; that is, using a priority contention window (CW). p Independent values. The term distribution refers to a specific range of values ​​from which the backoff counter can be randomly selected. In the second variant, known as type A2, the backoff counter for each CC in a group is set from the maximum priority contention window CW of the CC group. p The distribution generates the same numbers.

[0089] For Type B, a single CC from a group of potentially accessible CCs is selected as the primary channel for the TRP to perform the CAT4 CCA process, and the remaining CCs in a group comprising multiple CCs are designated as secondary channels. If the CAT4 CCA is successful for the primary CC, the secondary CCs can perform a shorter single-trigger CCA process, such as CAT2 CCA, on them immediately before the TRP can access the primary and secondary CCs. If the TRP needs to apply self-delay after a successful backoff following the CAT4 CCA, a single-trigger CCA process can also be performed on the primary CC before the TRP can access the primary and secondary CCs. Type B also has two variants that generate a backoff counter for a randomly selected primary CC from the group of CCs accessible to the TRP. In the first variant, known as Type B1, the backoff counter for the selected primary CC is generated from a group of CCs with a common CW. p Generated from a single public distribution, regardless of the CW of the chosen master CC. p The actual value. In the second variant, known as type B2, the backoff counter of the selected primary CC is set according to the maximum CW across the CC set. p The numbers generated by the distribution.

[0090] The following description refers to joint access of multiple TRPs. It should be understood that although most of the examples described are about joint access of multiple TRPs, the same principles can be applied to multiple antenna panels on a single TRP, or multiple antenna panels on each of the multiple TRPs used for joint access.

[0091] The aspects of this disclosure can provide joint TRP access to multiple channels in a manner consistent with existing aspects of new radio (NR). This can be achieved by combining spatial domain type A and type B-like procedures, as well as frequency domain type A and type B-like multichannel access procedures. In this joint TRP mechanism, one or more of the following techniques can also be used: A “CCA failure” occurs when a TRP detects a signal on a channel and therefore considers the channel unavailable. A “missed target” occurs when a TRP determines that it cannot complete its backoff procedure before the scheduled target start time. A TRP “CCA failure” or “missed target” indication triggered by the corresponding event can be sent to a controller to improve the efficiency of the operation of other TRPs in the group for the joint access procedure. For example, if the previous start time depends on the TRP experiencing a “CCA failure” or “missed target”, the indication can achieve an earlier (backward) alignment of the transmission start time than the previous target start time alignment. Another technique could include switching from performing Wideband (WB) CCA simultaneously on multiple channels to performing individual subband CCAs during the same channel access attempt, to avoid unintentionally identifying that if fewer than all channels trigger a “CCA failure” using their respective subband CCAs, then all channels in the set for which WB CCA is performed become unavailable. Another technique could include using TRP on-demand blanking within the acquired Channel Occupancy Time (COT), i.e., transmitting a portion of the time-domain resources of a given accessible channel, to allow the TRP additional opportunities for later joint access within the COT. A “CCA success” occurs when the TRP does not detect a threshold energy level on the channel, thus the channel is considered available for the TRP's transmission or reception. When using CAT2 CCA for spatial domain secondary TRPs, the TRP “CCA success” indication sent by the TRP can achieve transmission alignment. DL and UL time slot configurations and dynamic indications associated with these time slot configurations can be aligned on the jointly acquired COT. The selection of the spatial domain primary TRP and channel access priority level can be performed based on a specific combination of the spatial domain similar to type A and type B procedures being used, as well as the frequency domain similar to type A and type B procedures. The backoff generator parameter CW can be performed based on a specific combination of the spatial domain similar to type A and type B procedures being used, as well as the frequency domain similar to type A and type B procedures. pSpatial domain updates and maintenance. DL transmission power can be reduced based on COTs transmitted simultaneously in the spatial domain.

[0092] Figure 4 , 5 Examples 6A, 6B, 7A, 7B, 8A, and 8B provide examples of joint TRP access to a single unlicensed channel by three TRPs. It should be understood that although these embodiments involve three TRPs, the principle applies to joint TRP access by two or more TRPs. Furthermore, although three TRPs are used in the examples, the same principle can be applied to multiple antenna panels with a single TRP or multiple antenna panels with more than one TRP.

[0093] Figure 4 , 5 Figures 6A, 6B, 7A, 7B, 8A, and 8B illustrate examples of signal timing allowing a group of TRPs to jointly access a medium. Each figure shows a timing diagram of three TRPs. These three TRPs are connected to the controller via at least one communication link, such as a backhaul or fronthaul link. Messages can be exchanged between the TRPs and the controller via the communication link. This communication link can be a wireless communication link, such as a microwave link, or a wired link, such as a fiber optic link. The controller can supervise one or more TRP groups. A TRP group may include one or more TRPs. The TRP may be an NR-U TRP. Each TRP group uses one or more unlicensed spectrum channels. Figure 4 , 5 In the cases of 6A, 6B, 7A, 7B, 8A, and 8B, there may be additional transmissions that have already been aligned before the content shown; that is, the content shown is not necessarily the first alignment transmission made by the three TRPs. Similarly, there may be additional transmissions following the example communication shown in the figure.

[0094] Figure 4 , 5 In the examples 6A, 6B, 7A, and 7B, the TRP group is associated with controller 402 and three TRPs 404, 406, and 408. Controller 402 is connected to each of the three TRPs 404, 406, and 408 via a backhaul link to exchange messages between controller 402 and each of the three TRPs 404, 406, and 408. For example, TRPs 404, 406, and 408 can provide controller 402 with controller-determined t target Required information. This information may include channel access parameters for the current or subsequent joint access period for the TRP, such as, but not limited to, burst endpoint or COT endpoint, contention window (CW) or corresponding backoff counter, channel access priority level p, and current backoff generator parameters CW. pTRPs 404, 406, and 408 can provide controller 402 with information such as whether the TRP missed the target, successfully completed the CCA, or failed to complete the CCA. Additionally, controller 402 can provide new or modified TRPs 404, 406, and 408. target And TRP may need any configuration information as part of the federated access process, such as, but not limited to, the type of federated access procedure. See below... Figure 4 , 5 Examples of different types of joint access are described in 6A, 6B, 7A, 7B, 8A, 8B, 9A, 9B, 10A, 10B, 10C, 11A, 11B, and 12. In some types of joint access, the TRP or unlicensed channel can be designated as the primary TRP or primary channel. These designations can be explicitly defined by controller 402, inherent in the joint access type, or determined by the TRP.

[0095] exist Figure 4 , 5 There are 17 consecutive time intervals labeled 1 to 17 in 6A, 6B, 7A, 7B, 8A, and 8B. Each labeled interval is defined by the boundary of a specific time unit. This time unit can be a time slot, micro-slot, subframe, or OFDM symbol in the unlicensed spectrum. This boundary is referred to below as the "alignment boundary." This alignment boundary can also be aligned with the boundary of a time unit in the licensed spectrum.

[0096] Figure 4 Two consecutive joint access periods are shown. For each TRP, each joint access period includes the first contention window for performing CAT4 CCA, the determined target start time for initiating downlink burst transmission (t... target The self-deferred interval before ) and the execution of CAT2 CCA in t target The previous second time period, the interval of the acquired COT. If the channel is sensed as idle during CAT4 and CAT2 CCA, i.e., the detected energy is below the ED threshold, then TRP will begin transmission. If the channel is detected as busy during CAT4, self-delay and CAT2 CCA will not occur, and CAT4 CCA will be attempted again.

[0097] exist Figure 4 In this process, each TRP can independently generate and maintain its own backoff counter for the Contention Window (CW), during which the Contention Window Action (CCA) occurs according to the corresponding priority level. This can be considered a spatially similar type A process. Each TRP controls its own CCA and data transmission on the channel. targetThe maximum transmission period (CW) of the three TRPs, indicated as the burst end (BE) time, depends on the longest transmission period of each TRP and the maximum contention window (CW) of the three TRPs. Therefore, each TRP can be provided for the failure of the initial CCA (iCCA) due to potential mutual blanking, as a result of different COTs. target The determination of t can be achieved by the TRP transmitting their respective CCA counters and transmission burst endpoints to the controller 402. The controller determines t target The controller can set the value of t. target Alignment, for example, quantization to the earliest possible alignment boundary. Then t target The value is provided to the TRP. In this example, t is the value of the first joint access period. target 418 occurs at the beginning of interval 4.

[0098] exist Figure 4 In the diagram, TRP1 404 illustrates CAT 4 CCA 409, which begins precisely at the start of interval 1. CAT 4 CCA 409 senses that the medium is idle, therefore CAT 4 CCA 409 is considered successful and the channel is available for TRP 1404. If the medium is sensed to be busy during CAT 4 CCA 409, CAT 4 CCA 409 is not considered successful, and TRP1 404 will not proceed. target Transmission occurs at 418. Following CAT4 CCA 409, a self-delayed interval 410 occurs, which occurs during the t-hour period used for the first joint access. target The process ends before 418. Then, because CAT2 CCA 411 is successful, TRP1 404 executes CAT2 CCA 411, which happens to be at t target Started before 418 and in t target 418 ends. If the medium is sensed as busy during CAT2 CCA 411, TRP1 404 will not be used for the first joint access period. target Transmission is performed using 418. The cycle of CAT2 CCA is represented as T. d ,exist Figure 4 The value is displayed as 34 μs. However, this example should not be considered as representing T... d Limited to this value only. Because the channel is accessible, TRP1 404 is transmitted and can receive bursts of data during COT 412, which ends at BE1. TRP1 404 has the longest COT of three TRPs in the first joint access period. The new CAT4 CCA 413 begins at the end of COT 412. The new CCA 413 is based on the random CW counter time. Figure 4In the example, due to this random selection of the counter time, the new CCA 413 is a shorter period than the first CCA 409. There is another self-delayed period 414 that does not occur until the new CAT2 CCA 415. The new CAT2 CCA 415 occurs at t for the second joint access period. target The process ends at 419, which occurs at the beginning of interval 11. t is used for the second joint access period. target 419 with the determination of t for the first joint access period target 418 is determined in the same way, that is, the TRP provides information to the controller, the controller makes a determination, and the controller sends a t for the second joint access period to the TRP. target 419. CAT 4 CCA 413 or CAT2 CCA 415 sensing media is idle, and TRP1 404 is in t target 419 begins transmission during COT 416, which ends at BE1, and bursts can be received. Following COT 416, another random-length CW 417 is shown for use in the third joint access period.

[0099] Figure 4 The operation of TRP3 408 is similar to that of TRP1 404. CAT4 CCA 420, with a random duration determined by TRP3 408, begins during interval 1 and does not detect signals on the channel. The first self-delayed interval 421 occurs after a successful CAT4 CCA 420. CAT2 CCA 422 occurs at t... target Started before 418 and in t target 418 ends. The duration of CAT2 CCA422 is indicated as T. d And it equals 34μs, which is comparable to Wi-Fi's Distributed Inter-frame Spacing (DIFS). However, it should be understood that this example should not limit the duration of CAT2CCA. Because the channel is considered accessible, TRP3 408 transmits and can receive bursts during COT423 ending at BE3. Figure 4In the example, COT 423 ends before the longer COT 412 of TRP1 404. TRP3 408 begins a new CAT4 CCA 424 after COT 423. However, TRP3 408 can detect the transmission of TRP1 404 because TRP1 404 is still transmitting at that time. Whenever CAT4 CCA is interrupted, the backoff counter is frozen, and iCCA repeats until successful. When iCCA succeeds, the backoff counter can be decremented again. Finally, CAT4 CCA 424 succeeds and a self-delay interval 425 occurs after CAT4 CCA 424. A new CAT2 CCA 426 is initiated in the second joint access period. target It started before 419 and in t target 419 ended. A new burst was sent, and UL reception can be achieved by TRP3 408 in t target 419 begins during COT 427, which ends with BE3. TRP 3 408 begins after COT 427 with a new CAT4 CCA 428 for the third joint access period.

[0100] Figure 4 The operation of TRP2 406 differs from TRP1 404 and TRP2 408 because it determines that the channel is inaccessible during the second joint access period. CAT4 CCA 430, with the random duration determined by TRP2 406, begins and successfully completes during interval 1. The first self-delayed interval 431 occurs after the successful CAT4 CCA 430. CAT2 CCA 432 occurs during the first joint access period. target Started before 418 and in t target 418 ended. Sudden 433 ended in BE2. In Figure 4In the example, COT 433 ends before the longer COT 412 of TRP1 404. TRP2 406 begins a new CAT4 CCA 434 after COT 433. However, TRP2 406 can detect transmissions of TRP1 404 or TRP3 408 because those TRPs are still transmitting at this time. Whenever CAT4 CCA is interrupted, the backoff counter is frozen, and iCCA is repeated until successful. When iCCA succeeds, the backoff counter can be decremented again. Although there is a duration 435 within CAT4 CCA 434, during which TRP2 406 does not sense channel busy, CAT4 CCA 434 is interrupted before its end, for example, due to some out-of-group transmissions. Based on the traditional CAT4 CCA mechanism, the TRP performs iCCA again until successful and freezes the remaining value of the TRP's random backoff counter. Since CATA CCA 434 was unsuccessful, there is no self-delay interval, no CAT2CCA, and TRP2 406 is not transmitted on the channel. During the second transmission period t... target After 419, TRP2 406 informs controller 402 of the remaining counter value of CAT4 CCA 434 that was not used for channel access during the second transmission period. TRP2 406 can then use this remaining counter duration for the next CAT4 CCA 437 in the third transmission cycle.

[0101] By not performing the CCA procedure during time intervals 9 to 14, TRP2 406 saves power and computational complexity, and behaves less aggressively by not continuously sensing the medium during this period. Similarly, during time intervals 9 to 14, TRP1 404 and TRP3 408 continue transmitting their respective bursts. Thus, even if TRP2 406 were to continue performing the CCA procedure during this period, TRP2 406 would sense that the medium is busy and the CCA procedure would fail. Therefore, TRP2 406 does not need to perform the CCA procedure during time intervals 9 to 14. This unlicensed spectrum access mechanism is thus more efficient than directly employing CAT4 CCA in 3GPP Release 13 while other TRPs in the group are transmitting.

[0102] Figure 5 The diagram illustrates two consecutive joint access periods, each including the pre-CCA delay interval before CAT4 CCA, the first contention window for CAT4 CCA execution, and ending at t. target This is used for sending bursts, and for the intervals used for burst transmission. It should be noted that because CAT4 CCA is in ttarget Alignment ends there, so no additional CAT2 CCA is needed. If the medium is idle throughout the entire CAT4 CCA, the TRP will continue sending bursts. If the medium is busy, the TRP will not send bursts because the channel is considered unavailable.

[0103] exist Figure 5 In this process, each TRP can independently generate and maintain its own backoff counter for CW, which occurs during CW according to the corresponding priority level CCA. This can be considered a process similar to type A. Each TRP controls its own CCA and data transmission on the channel. The t used for each joint access period... target It depends on the longest BE and the largest CW among the three TRPs. In this example, t is used for the first joint access period. target It is located at the beginning of interval 4. Figure 4 and Figure 5 The differences between them include, in Figure 4 In this context, for each joint access period, there is a delay between CAT4 CCA and CAT2 CCA, while... Figure 5 In this context, for each joint access period, the delay time precedes the CAT4 CCA, and the CAT4 CCA is aligned to the t value within that joint access period. target Finish.

[0104] exist Figure 5 In the diagram, TRP1 404 is shown as having a pre-CCA delay interval 505 that ends at the start of CC4 CCA 509. The pre-CCA delay interval 505 is exactly at... Figure 5 The interval 1 in the sequence begins. This is based on the end time of the previous joint access period, the known duration of the CAT4 CCA of the current joint access period, and the next t. target The pre-CCA delay interval 505 is determined. CAT4 CCA 509 detects medium idle, therefore CAT4 CCA 509 is considered successful because the channel appears to be accessible. If the medium is sensed as busy during CAT4 CCA 509, then CAT4 CCA 509 is unsuccessful because the medium idles during the first joint access period from t... target The channel has been inaccessible since 518. CAT4 CCA 509 was used for the first joint access period. target End before 518. TRP1 404 in t target518 begins transmission at the end of BE1 from COT 512 and can receive bursts. A new pre-CCA delay interval 513 occurs from the end of COT 512 until the next CAT4 CCA 514. CAT4 CCA 514 begins at the end of the pre-CCA delay interval 315. The new CCA 514 is based on a random CW counter time and is scheduled for the next t-period used for the second joint access period. target 519 is over, now it's time for the next t target 519 occurs at the beginning of interval 11. t is used for the second joint access period. target 519 with the determination of t for the first joint access period target 518 is determined in the same manner. CAT4 CCA 514 senses a medium idle, and TRP1 404 transmits and can receive bursts during COT 515, which ends at BE1. A new CCA pre-delay interval 516 occurs from the end of COT 515 until the next CAT4 CCA 517. CAT4 CCA 517 begins at the end of CCA pre-delay interval 516. The new CCA 517 is based on a random CW counter time and is scheduled for the next t for the third joint access period. target May 28th is over.

[0105] Figure 5 The operation of TRP3 408 is similar to that of TRP1 404. The pre-delay interval 520 of CCA begins at interval 1 and ends at the start of CAT 4 CCA 521. No signal was detected during CAT4 CCA 521, therefore CCA 521 is considered successful because the channel appears to be accessible. CAT4 CCA 521 occurs precisely at t target End before 518. TRP3 408 in t target Transmission begins at 518 during COT 522, which ends at BE3, and bursts can be received. A new pre-CCA delay interval 523 occurs from the end of COT 522 until the next CAT4 CCA 524. CAT4 CCA 524 begins at the end of the pre-CCA delay interval 523. The new CCA 524 is based on a random CW counter time and is scheduled to occur at t. target519 ends. CAT4 CCA 524 senses the channel is idle, and TRP3 408 transmits or receives a burst during COT 525, which ends at BE3. A new CCA pre-delay interval 526 occurs from the end of COT 525 until the next CAT4 CCA 527. CAT4 CCA 527 begins at the end of CCA pre-delay interval 526. The new CCA 527 is based on a random CW counter time and is scheduled for t during the third joint access period. target May 28th is over.

[0106] Figure 5 The operation of TRP2 406 differs from TRP1 404 and TRP2 408 because it determines that the channel is unaccessible in the second joint access segment. The pre-delay interval 530 of CCA begins within interval 1 and ends when CAT4 CCA 531 begins. CCA 531 senses that the channel is idle, therefore CCA 531 is considered successful because the channel appears to be accessible. CAT4 CCA 531 occurs precisely at t target The process ends before 518. TRP2 406 is transmitted during COT 532, which ends at BE2, and bursts can be received. A new CCA pre-delay interval 533 occurs from the end of COT 532 to the next CAT4 CCA 534. CAT4 CCA 534 begins at the end of CCA pre-delay interval 533. CAT4 CCA 534 is based on a random CW counter time and is scheduled to occur at t target End of 519. During CAT4 CCA 534, TRP2 406 sensed the channel was busy, therefore CAT4 CCA 534 failed. Because CAT4 CCA 534 failed, TRP2 406 did not occur on that channel. target After 519, TRP2 406 notifies controller 402 of the remaining counter duration of the CAT4 CCA 534 that was not used during the second joint access period. TRP2 406 can then use this remaining counter duration for the third joint access period. target The next CAT4 CCA before 528 is 537.

[0107] Figure 6A This is another example of a set of TRPs for joint access media. In this case, back-to-early alignment is shown. If t is given in the joint access period... target For TRP-based BE or CW, due to unsuccessful CAT4 CCA, the TRP is removed from the given joint access period t. target If it does not access that channel, then the earlier t target It is possible. Figure 6A The first joint visit period and Figure 4 The same as in, and Figure 6A The various features in are therefore labeled as... Figure 4 The same applies until the end of the first joint visit period.

[0108] The second joint visit period t target The time is initially determined by controller 402 as the BE of TRP1 402 based on the previous joint access period, in this case the first joint access period, and in the CW of TRP2 406 based on the first joint access period. Because TRP2 406 will not transmit in the second joint access period due to the unsuccessful CAT4 CCA 434, the time determined instead of BE1 (BE of TRP1 404) and CW2 (CW of TRP2 406) is... target The controller 402 can determine the new time based on BE1 of the previous joint access period and the second longest CW of the previous joint access period. target Time. In Figure 6A In the example, the second longest CW is CW3 (CW of TRP3 408).

[0109] If the second longest CW belongs to a TRP that is not transmitted due to an unsuccessful CAT4 CCA, the controller 402 can generate a new t based on the third longest CW, etc. target .

[0110] When a TRP has an unsuccessful CCA, the TRP sends a "missed target" indication to the controller, indicating that the TRP will withdraw from the current joint access period. target This indicates that no transmission will be performed. This indication is equal to the original t. target It occurs after the time point when the remaining part of CW is subtracted from the original time.

[0111] See Figure 6A The missed target indication time 612 equals the original t target 419 minus the remaining counter duration of CW (remaining CW2) 610 of TRP2 406. Therefore, at the missed target indication time 612, TRP2 406 indicates to controller 402 that for TRP2 406, the burst transmission will not occur at t. target Therefore, controller 402 can determine the new t based on BE1 and CW3. target Controller 402 notifies TRP1 404 and TRP3 408 of the modified t target .

[0112] When the modified t is received in TRP1 404 targetWhen executing CAT2 CCA 620, it successfully modified the t target End. Following CAT2 CCA 620, TRP1 404 is transmitted and can be received during COT 622, which ends at BE1. Another random-length CW 623 is shown after COT 622 for use in a third joint access period.

[0113] When the modified t is received in TRP3 408 target At that time, CAT2 CCA 630 was executed, which successfully modified the t target End. Following CAT2 CCA 630, TRP3 408 is transmitted and can be received during COT 632, which ends at BE3. Another random length CW 633 is shown after COT 632 for use in the third joint access period.

[0114] In an alternative approach to accessing the channel via a set of TRPs comprising multiple TRPs, one TRP in the set is selected as the spatial domain primary TRP, and the remaining TRPs in the set are designated as spatial domain secondary TRPs, similar to a frequency domain type B process. The selection of the spatial domain primary TRP can be random, round-robin, or by a first TRP and other TRPs that truncate any ongoing CAT4 CCA, indicating that the first TRP is the spatial domain primary TRP for that joint access period.

[0115] The space domain master TRP notifies the controller of a successful CAT4 CCA process upon completion. This notification can be made via a "CCA Success" indication.

[0116] It can have the largest CW from all TRPs p The distribution generates the backoff counter for the spatial domain primary TRP, similar to the frequency domain B2 type process. Furthermore, the maximum COT (MCOT) associated with the channel access parameters used by the spatial domain primary TRP is applied to the transmission of both the spatial domain primary TRP and its spatial domain secondary TRPs.

[0117] The transmission power of each TRP that successfully acquires the channel can be reduced by sending multiple TRPs simultaneously, which helps to mitigate interference and control transmission power during joint access periods.

[0118] Figure 6B It shows the relationship with Figure 6ASimilar examples. However, instead of TRP1 404, there is a self-delay, for example, as shown in Figure 6, a self-delay 410 in the first joint access period between CAT4 CCA 409 and CAT2 CCA 411, in Figure 6B In the middle, after CAT4 CCA 650 ends on the channel, backoff CCA 651 is executed until t. target 418. Note that because TRP1404 continues to sense the channel after the backoff period ends, CAT2 CCA does not need to immediately precede the transmission. A similar process occurs for the second joint access period of CAT4 CCA653 and post-backoff CCA 654. Figure 6A In a similar manner, because TRP2 406 is unsuccessful for CAT4 CCA 660, TRP2406 notifies the controller and other TRPs of the failure, while the original arrangement of t target For reference Figure 6A The description was modified to reflect an earlier time.

[0119] Figure 7A The diagram illustrates two consecutive joint access periods, each consisting of the first contention window for CAT4 CCA performed for the selected spatial domain master TRP, and the determined t... target The previous self-deferred interval, the execution of CAT2 CCA in t target The preceding second predefined time period and the interval of the transmission burst. For each spatial domain secondary TRP, each time period includes the self-delay interval before CAT2 CCA, the predefined time period for performing CAT2 CCA, and the interval of the transmission burst. If the CAT4 CCA and CAT2 CCA of the spatial domain primary TRP and / or the CAT2 CCA of the spatial domain secondary TRP senses that the channel is idle, the corresponding TRP will be entitled to access the channel to be used in the second time period. target The channel is transmitted from t. If the channel is busy during either CAT4 CCA or CAT2 CCA of the primary TRP, the primary TRP will not access the channel. If the primary TRP senses the channel is busy during CAT4 CCA, or the secondary TRP senses the channel is busy during its CAT2 CCA, the secondary TRP will also not access the channel. If the primary TRP senses the channel is not busy during CAT4 CCA, but busy during CAT2 CCA, and the secondary TRP senses the channel is not busy during its CAT2 CCA, the secondary TRP can access the channel. Furthermore, if the primary TRP is busy from t target T mtIf the channel is detected as busy during the previous CAT4 CCA, then when using self-delay, the spatial domain primary TRP will not perform CAT CCA, and the spatial domain secondary TRP may also not perform CAT2 CCA, for example, when receiving a CCA failure indication.

[0120] exist Figure 7A In this embodiment, TRP1 404 is selected as the primary TRP for the spatial domain during the first and second joint access periods. In other embodiments, it should be understood that the spatial domain can primarily change from one joint access period to another. TRP1 404 generates and maintains its own backoff counter for the contention window (CW), during which CCA occurs according to the corresponding priority level. This can be considered a type B spatial domain procedure. TRP1 404 controls its own CAT4 CCA and CAT2 CCA procedures, as well as data transmission or reception on the channel. TRP2 406 and TRP3 408 are secondary TRPs for the spatial domain and control their CAT2 CCA procedures, as well as data transmission or reception on the channel. Note that for a type B spatial domain procedure, t target It only depends on the BE contention window (CW) with the primary TRP of the space domain, and does not need to be transferred to the secondary TRP of the space domain if a CCA success indication is adopted. In this example, the t of the first joint access period target It is located at the beginning of interval 3.

[0121] exist Figure 7A In the diagram, the space domain master TRP1 404 is shown performing CAT4 CCA 710, which begins precisely at the start of interval 1. CAT4 CCA 710 senses that the channel is idle, therefore CAT CCA 710 is considered successful because the channel appears to be accessible. If the channel is sensed to be busy during CAT4 CCA 710, then CAT4 CCA 710 will not be successful, and the space domain master TRP1 404 will not perform CAT4 CCA 710 during the first joint access period. target Transmission occurs at 709. After CAT4 CCA710, it happens exactly at t target The self-deferred interval 711 ends before 709. The spatial domain master TRP1 404 then executes CAT2 CCA 712, which happens to be at t... target It started before 709 and in t target 709 ended because CCA712 was successful. The duration of CAT2 CCA 512 was indicated as T. dThis can be equal to 34 μs. However, it should be understood that this example should not limit the duration of CAT2 CCA. If channel busy is sensed during CAT2 CCA 712 and CAT2 CCA 712 is unsuccessful, then TRP1 404 will not be available at t. target Access channel 709. The time period of CAT2 CCA is represented as T. d TRP1 404 in t target Transmission begins at 709 during COT 713, which ends at BE1, and bursts can be received. The new CAT4 CCA 714 begins at the end of COT 713. The new CCA 714 is based on a random CW counter time. There is another self-delayed period 715 that does not occur until the new CAT2 CCA period 716. The new CAT2 CCA period 716 occurs during the second joint access period. target 717 ended, t target 717 occurs at the beginning of interval 11. target 717 with t used for the first joint access period target The same method is used to determine 709. CAT4 CCA 714 or CAT2 CCA 716 senses that the channel is idle, and TRP1 404 sends burst 718.

[0122] The spatial domain auxiliary TRP3 408 is shown as being executed in t target It started before 709 and in t target CAT2 CCA 720 ends at 709. The duration of CAT2 CCA 720 is indicated as T. mt ≥T f T mt The aim is to define the CAT2 CCA duration for auxiliary TRPs in multiple frequency or spatial domains. T can be considered... f This is equal to 25μs, which is comparable to the Priority Inter-frame Spacing (PIFS) of WiFi. However, it should be understood that this example should not limit the duration of CAT2 CCA. TRP3 408 transmits and can receive bursts during COT 721. Figure 7A In the example, the burst during COT 721 ends before the longer COT 713 of the space domain master TRP1 404. When RP3 408 completes its burst during COT 721, TRP3 408 waits until another CAT2 CCA 725 is used for the second joint access period. target It started before 717 and in t targetEnd of 717. TRP3 408 is sent as a secondary TRP for the spatial domain during COT 726 and can receive another burst.

[0123] Figure 7A The operation of the spatial domain secondary TRP2 406 is similar to that of the spatial domain secondary TRP3 408, except that the channel is found to be inaccessible during the second joint access period. The spatial domain secondary TRP2 406 is shown as performing operations in t target It started before 709 and in t target CAT2 CCA 730 ends at 709. TRP2 406 transmits during COT 731 and can receive bursts. TRP2 406 lies dormant until another CAT2 CCA 735 is used for the second joint access period. target It started before 717 and was scheduled to be in t target End of 717. In this case, CAT2 CCA 735 fails and considers TRP2 406 to be inaccessible on the channel.

[0124] In another embodiment where spatial domain B type is not captured in the figure, a self-delay period and CAT2 CCA may not be required after a successful CAT4 CCA of the spatial domain primary TRP. Instead, the spatial domain primary TRP can immediately fill the time gap (if any) with micro-slots / partial subframes and / or cyclic prefix (CP) extensions upon successful CAT4 CCA, up to the earliest alignment boundary, thereby initiating transmission. In this case, CAT2 CCA of the spatial secondary TRP is performed so that it ends at the transmission start point of the spatial domain primary TRP, for example, based on prior knowledge of the CW period or backoff counter value of the spatial domain primary TRP.

[0125] The TRP selected as the master TRP in the spatial domain can apply channel access parameters, such as, but not limited to, burst or COT endpoints, contention window (CW) or corresponding backoff counters, channel access priority level p, and current backoff generator parameters CW. p And the range of the competition window, for a given priority level (CW) min，p CW max，p ), from minimum to maximum, corresponds to the lowest channel access priority level among all the levels processed by all TRP groups. This lowest channel access priority corresponds to the maximum value of p.

[0126] The backoff counter of the spatial domain master TRP starts from [0, CW p The uniform distribution between [ ] is randomly generated, where CW min，p ≤CWp≤CW max，p . Originally, C.W. pThe value can be set to CW min，p .

[0127] If at least a predetermined percentage of the hybrid automatic repeat request acknowledgement (HARQ-ACK) values ​​corresponding to all spatial transmissions on the channel are determined to be negative acknowledgements (NACK), then the CW of the space primary TRP is... p The value can be increased for each priority level up to the next higher allowed value. Otherwise, CW p The value will be reset to CW. p =CW min，p .

[0128] Figure 7B It shows the relationship with Figure 7A Similar examples, except that the TRP is designated as the space domain master TRP, can declare itself as the space domain master TRP by sending notification messages to the controller or other TRPs, or both, such as a CCA success indication, indicating that the first TRP that successfully completed CAT4 CCA has done so. Therefore, in addition to as referenced... Figure 7A The TRP1 404 described herein was selected as the primary space domain TRP prior to the first CAT4 CCA at the start of the first joint access period. Figure 7B In the first joint access period, TRP1 404 is designated as the master space domain TRP because it is the first TRP to complete CAT4 CCA. TRP1 404 sends notifications to controller 402, TRP2 406, and TRP3 408 to inform them that it has successfully completed CAT4 CCA 740 and declares itself as the master space domain TRP for the first joint access period. In the second joint access period, TRP3 408 is the first TRP to complete CAT4 CCA. TRP3 408 sends notifications to each of controller 402, TRP2 406, and TRP1 404 to inform them that it has successfully completed CAT4 CCA 750 and declares itself as the master space domain TRP for the second joint access period.

[0129] When TRP2 406 receives notification from TRP1 404 that it has declared itself the space domain master TRP for the first joint access period, TRP2 406 truncates its CAT4 CCA and relinquishes its remaining CW to assume the role of the space domain secondary TRP. TRP2 406 generates a new backoff counter value to be used in the second joint access period. The same process occurs when TRP3 408 receives notification from TRP1 40 that it has declared itself the space domain master TRP.

[0130] Figure 8A Two joint access periods are shown, each illustrating a different embodiment utilizing the gaps within the COT during the joint access period. Refer to the description of the use of three antenna panels associated with and controlled by the gNB. Figure 8A This embodiment can also be applied to situations where multiple TRPs are multiple gNBs or controllers controlling other spatially separated network nodes, such as... Figure 4 , 5 As shown in examples 6A, 6B, 7A, and 7B. Therefore, in Figure 8A The system comprises a main spatial domain panel and multiple auxiliary spatial domain panels. A first joint access period illustrates a first embodiment that includes using on-demand or pre-configured blanking modes to enable the auxiliary spatial domain panels to have later joint access in the event of an earlier CCA failure. A second period illustrates a second embodiment involving the use of blanking gaps to switch between downlink and uplink transmissions on the channel within the joint access period.

[0131] For the selected spatial domain master panel, the first joint access period includes the first contention window for executing CAT4 CCA, the self-deferred interval after the first contention window, and exactly at the determined t target The second contention window for CAT2 CCA, and the interval for accessing the channel, can include transmit and receive data bursts. Within this interval of the transmit or receive data burst, one or more small duration windows can occur, which are used for CAT2 CCA by a panel serving as an inter-domain auxiliary panel. These one or more small duration windows can occur on demand or be pre-configured. If a small duration window is blanked for more than a predetermined period, where a non-limiting example is 25 μs, CAT2 CCA can be performed before COT transmission resumes.

[0132] For each spatial domain auxiliary panel, each period includes the self-delayed interval before CAT2 CCA, exactly at t target The predefined period for CAT2 CCA is previously executed, along with the intervals for transmitting and receiving data bursts. One or more small duration windows can occur within the intervals used to transmit or receive data bursts, which can be used for CAT2 CCA by other panels acting as secondary panels in the spatial domain. These small duration windows can occur on demand or be pre-configured. If the CAT4 CCA and CAT2 CCA of the primary spatial domain panel and / or the CAT2 CCA of the secondary spatial domain panel senses an idle channel, each panel will continue transmitting data bursts.

[0133] If channel busy is sensed during either CAT4 CCA or CAT2 CCA of the main spatial domain panel and / or during CAT2 CCA of the secondary spatial domain panel, the corresponding panel may be unable to [operate / receive] t target Transmission begins at the start. According to some embodiments, if a panel is initially unable to transmit via a gNB, the gNB schedules one or more small duration blanking windows for each panel, allowing one or more panels to determine whether the channel has been idle since the last CCA and permitting the panel to transmit within a certain timeframe. target After accessing the channel, a panel that begins transmission after a successful CAT2 CCA within a small duration window may not be able to send all the expected data bursts because the allowed transmission time is limited by the maximum channel occupancy time (MCOT) of the spatial domain master panel during the current joint access period.

[0134] According to some embodiments, there may be a pattern of one or more pre-configured small duration blanking windows that are scheduled to occur regardless of whether any panel specifically indicates that the CCA process has failed.

[0135] Panels that have successfully acquired a channel can blank the joint access period for at least 25 μs before one or more subsequent alignment boundaries, either in a pre-configured or on-demand mode. This mode can be based on the CAT2 failure indication of the spatial domain auxiliary panel. If the transmission blanking exceeds 25 μs, the blanking panel can also apply CAT2 CCA before resuming data COT transmission.

[0136] For the selected spatial domain master panel, the second joint access period includes the first contention window for executing CAT4 CCA, the self-deferred interval after the first contention window, and the execution in t target The preceding first CAT2 CCA occurs during the second predefined period, and the COT is used for the transmission of DL data bursts and the reception of UL data bursts. Within the COT, there are one or more small duration windows that act as protection windows to mitigate interference during the handover between downlink and uplink transmissions within the joint access period. CAT2 CCA can also be performed during the handover duration between DL and UL transmissions to ensure that the channel remains idle for the anticipated new transmission. For each spatial domain auxiliary panel, each joint access period includes t targetThe initial predefined period for the first CAT2 CCA and the COT for the transmission of DL data bursts and the reception of UL data bursts are previously executed. This COT also includes one or more small duration windows that act as guard windows to mitigate interference during the handover between downlink and uplink transmissions within the joint access period. If the CAT4 and CAT2 CCA of the spatial domain primary TRP and / or the CAT2 CCA of the spatial domain secondary panel senses an idle channel, the corresponding TRP will continue transmission. If the channel is sensed to be busy during either the CAT4 or CAT2 CCA of the spatial domain primary panel and / or the CAT2 CCA of the spatial domain secondary panel, the individual panels may be unable to transmit from the t... target Transmission begins.

[0137] If the panel fails to access the channel earlier in the joint access period, it may perform CAT2 CCA during any of one or more small duration windows. If successful, CAT2 CCA may enable the panel to transmit on the channel scheduled for the upcoming portion of the joint access period.

[0138] In some embodiments, a panel that successfully acquires a channel uses a matching DL / UL slot configuration for its acquired Channel Occupancy Time (COT). This can be achieved, for example, by indicating the same Slot Format Indication (SFI). Panels that fail the initial CCA can perform CAT2 CCA during the handover interval for later joint access. If a later access panel successfully completes CAT4 CCA before acquiring a channel, its COT is not limited by the spatial domain primary MCOT.

[0139] It should be understood that, despite Figure 8A The two joint access periods shown are consecutive joint access periods. Figure 8A Two exemplary joint access periods are shown, demonstrating how blanking modes can be used in at least two different ways, i.e., regardless of previous failed CCAs, allowing for later joint access by using on-demand or pre-configured blanking modes or during the switching gap between DL and UL transmissions.

[0140] exist Figure 8AIn this configuration, panel 1 804 is selected as the primary panel for the spatial domain. Therefore, panel 1 804 generates and maintains its own backoff counter for the contention window (CW), during which CCA occurs according to the corresponding priority level. This can be considered a process similar to type B. gNB 802 controls CAT 4 CCA and CAT 2 CCA processing, as well as data transmission on the channel of panel 1. Panels 2 806 and 3 808 are secondary panels for the spatial domain; their CAT 2 CCA processing, blanking processing, and data transmission on the channel are controlled by gNB 804. The target transmission time t is set when the channel is deemed idle to begin transmitting a burst during COT. target It depends only on the previous BE and the contention window (CW) of the space domain main panel, and if a CCA success indication is adopted to allow the application of the self-delay period on the space domain main panel, no transmission to the space secondary TRP is required. In this example, t of the first joint access period target It is located at the beginning of time interval 3.

[0141] exist Figure 8A In the first joint access period, the spatial domain master panel 1804 is shown performing CAT4 CCA 810, which begins precisely at the start of interval 1. The channel is sensed as idle by CAT4 CCA 810, therefore CAT4 CCA 810 is successful and the channel is considered available for transmission. If a signal is detected during CAT4 CCA 810, then CAT4 CCA 810 will not be successful, and the spatial domain master panel 1804 will not perform CAT4 CCA 810 during the first joint access period. target 809 Transmission. Following CAT4 CCA 810, a self-delayed interval 811 occurs before the target 809. Then, panel 1 804 executes exactly at t target It started before 809 and in t target CAT2 CCA 812 ends at 809. CAT2 CCA 812 succeeded. If channel busy was sensed during CAT2 CCA 812 and CAT2 CCA 812 was unsuccessful, then panel 1 804 will not be active at t. target Transmission is performed at 809. The time period for CAT2 CCA 812 is represented as T. d Within the main MCOT 813, panel 1 804 transmits data at t. targetBurst 813A begins at 809. During data MCOT 813, before the start of interval 4, the first blanking window begins. As described above, this blanking window may be the result of one or more pre-configured blanking windows scheduled during main MCOT 813, or it may be one or more blanking windows scheduled on demand due to, for example, panel 2 806 with unsuccessful CAT2 CCA, and gNBs scheduling blanking windows for possible subsequent access. CAT2 CCA 814A is executed during the first blanking window, which ends at the start of interval 4. CAT2 CCA 814A succeeds and burst 813B continues. The second blanking window occurs before the start of interval 5, during which CAT2 CCA 814B is executed. CAT2 CCA 814B succeeds and burst 813C continues to complete. After burst 813C completes transmission, a new CAT4 CCA 815 begins. After a successful CAT4 CCA 815, there is a brief self-delay period 816, which ends before CAT2 CCA 817. Despite Figure 8A The diagram shows two blanking windows. It should be understood that the number of blanking windows can vary depending on the duration of the joint access and can also vary based on whether the blanking windows are pre-configured or provided on demand.

[0142] Regarding the spatial domain auxiliary panel 2 860, during the first joint access period, this panel is shown performing CAT2 CCA 830, which begins exactly before interval 3 and ends at the beginning of interval 3. The channel is sensed to be busy during CAT2 CCA 830, therefore CAT2 CCA 830 is unsuccessful, and thus no t is displayed at panel 806. target Transmission begins at 809. Panels 1 (804) and 3 (808) are notified of the failure of CAT2 CCA 830. If no pre-configured blanking window is scheduled, it can trigger on-demand use of one or more blanking windows to allow panel 2 (806) to join the joint access period later. By using on-demand blanking, the first blanking window occurs and CAT2 CCA 832 is executed before the start of interval 5. CAT2 CCA 832 succeeds and burst 833 begins. The duration of burst 833 is limited based on the maximum time (primary MCOT) allocated to the spatial domain master panel 1 (804). After burst 833 completes, there is an inactive period until a new CAT2 CCA 835 begins before interval 11 in the second joint access period.

[0143] Regarding the spatial domain auxiliary panel 3 808, during the first joint access period, panel 3 808 executes exactly at t target It started before 809 and in t targetCAT2 CCA 840 ended at 809. CAT2 CCA 840 was successful. During COT 841, panel 3 808 transmitted at t target Burst 841A begins at 809. During COT 841, the first blanking window begins before the start of interval 4. CAT2 CCA 842A is executed within the blanking window and ends at the start of interval 4. CAT2 CCA 842A succeeds and burst 841B continues. Before the start of interval 5, the second blanking window occurs, and CAT2CCA 842B is executed within the blanking window. CAT2 CCA 842B succeeds and burst 841C continues to complete. After burst 841C completes its transmission, a new CAT4 CCA 815 begins. After burst 841C completes, there is an inactive period until a new CAT2 CCA 843 begins before interval 11 in the second combined access period.

[0144] As described above, the second joint access period is used to illustrate the later joint access utilizing the DL / UL switching gap. Panel 1804 is again the main panel of the spatial domain, and panels 2806 and 3808 are auxiliary panels of the spatial domain.

[0145] Referring to panel 1 804, CAT2 CCA 815 was successfully executed during the second joint access period, followed by a self-delayed period 816. In t target Before 829, CAT2 CCA 817 is successfully executed. After CAT2 CCA 817, DL data COT 818 occurs. A switching gap 819 follows DL data COT 818 and ends at the beginning of interval 13. Switching gap 819 allows the transition from DL to UL and reduces the risk of interference between DL and UL communications. Before the end of switching gap 819, another CAT2 CCA 820 occurs, and switching gap 819 ends at the beginning of interval 14. After a successful CAT2 CCA 820, UL data COT 821 occurs. After UL data COT 821, another switching gap 822 exists to allow the transition back from UL to DL. Before the end of switching gap 822, another CAT2 CCA 823 occurs. After a successful CAT2 CCA 822, another DL data COT 824 occurs.

[0146] Reference panel 2 806, during the second joint access period, at t targetCAT2 CCA 835 is executed before 829. CAT2 CCA 835 is unsuccessful, therefore there is no transmission from panel 2 806 because the channel is considered unavailable. The first switching gap 836 occurs exactly before interval 13, aligned with the DL / UL switching gap seen from panel 1 804. CAT2 CCA 836 is not actually executed because the DL and UL configurations match across panels and panel 2 806 cannot start because it cannot access the UL. The second switching gap 837 occurs exactly before interval 14, aligned with the UL / DL switching gap seen from panel 1 804. Another CAT2 CCA 838 occurs before the end of switching gap 837. After a successful CAT2 CCA 838, DL data COT 839 occurs.

[0147] Referring to panel 3 808, during the second joint access period, after a successful CAT2 CCA 843, DL data COT 844 occurs. Following DL data COT 844, a switching gap 845 exists, ending at the start of interval 13. Before the end of switching gap 845, which ends at the start of interval 13, another CAT2 CCA 846 occurs. After a successful CAT2 CCA 846, UL data COT 847 occurs. After UL data COT 847, another switching gap 848 exists to allow a switchback from UL to DL. Before the end of switching gap 848, another CAT2 CCA 849 occurs. After a successful CAT2 CCA 849, another DL data COT 850 occurs.

[0148] Figure 8B The second joint visit period is shown to be similar to Figure 8A An example of the first joint visit period. Figure 8B During the first joint access period, TRP1 804 is the first to complete CAT4 CCA 860. TRP1 804 sends notifications to controllers 802, TRP2 806, and TRP3 808, informing them that TRP1 804 has successfully completed CAT4 CCA and declaring itself the space domain master TRP for the first joint access period. It then executes backoff CCA 861 until CAT2 CCA 862. TRP2 806 and TRP3 808 execute CAT4 CCA 870 and 880, and CAT2 CCA 871 and 881, respectively.

[0149] During the second joint access period, TRP3 808 is the first TRP to complete CAT4 CCA. TRP3 808 sends a notification to controller 802, TRP2 806 and TRP1 804, informing them that TRP3 808 has successfully completed CAT4 CCA 882 and declaring itself as the space domain master TRP for the second joint access period.

[0150] TRP2 806's execution of CAT4 CCA 872 failed, and its execution of CAT2 CCA 873 also failed. TRP2 806 sends a notification of the failure of TRP3 808 for CAT2 CCA to controller 802, TRP2 806, and TRP1 804. This notification from TRP2 806 can lead to on-demand blanking configuration of the TRP implementation to allow for later federated access to TRP2 806, as referenced. Figure 8A The first joint visit period described in the text.

[0151] In some embodiments, if available, data bursts may use cyclic prefix (CP) extension to preserve the duration of fractional symbols.

[0152] Figure 9A , 9B Figures 10A, 10B, 10C, 11A, 11B, and 12 illustrate additional example scenarios of joint access to unauthorized spectrum. Figure 9A , 9B 10A, 10B, 10C, 11A, 11B and 12 show references. Figure 4 Examples of how the embodiments described in sections 8, which involve joint access to a group of TRPs or panels comprising multiple TRPs, can be combined to provide joint access to more than one channel by a group of TRPs or panels comprising multiple TRPs or panels. Figure 4 , Figure 5 , Figure 6A and Figure 6B Examples are described as spatial domain-like processes of type A, while Figure 7A , 7B Examples 8A and 8B are described as spatial domain-like type B processes. In the case of coordinating multiple TRPs on multiple unlicensed channels, spatial domain-like type A processes can be combined with frequency domain-like type B processes (as referenced). Figure 9A and 9B (Described), combining spatial domain similar type A processes with frequency domain similar type A processes (e.g., referring to...) Figure 10A , 10B (as described in 10C), combining spatial domain-like type B processes with frequency domain-like type B processes (e.g., referring to...) Figure 11A and11B (Described) or combining spatial domain-like type B processes with frequency domain-like type A processes (e.g., referencing) Figure 12 (Described).

[0153] Figure 9A The example TRP group includes TRPs 904, 906, and 908, which are associated with controller 902 and the three TRPs 904, 906, and 908. Controller 902 is connected to each of the three TRPs 904, 906, and 908 via a backhaul link.

[0154] Despite Figure 9A , 9B In embodiments 10A, 10B, 10C, and 11A, the channels are shown as adjacent, which is not considered necessary in all embodiments involving a combination of a spatial domain-like type A process and a frequency domain-like type B process, or a combination of a spatial domain-like type B process and a frequency domain-like type B process, or a combination of a spatial domain-like type B process and a frequency domain-like type A process. In some embodiments, the channels accessed by the TRP or panel may be discontinuous in the frequency domain. For example, in Figure 12 In this context, not all accessed channels are shown as adjacent.

[0155] For example, such as Figure 10A , 10B As shown in 10C and 11B, the embodiments concerning the combination of spatial domain similar type A processes and frequency domain similar type A processes, as well as the use of broadband CCA, only include adjacent channels.

[0156] exist Figure 9A , 9B 10A, 10B, 10C, 11A, 11B, and 12 contain consecutive time intervals marked 1 to 17. These marked intervals are the boundaries of specific time units. This time unit can be a time slot, micro-slot, subframe, or OFDM symbol in the unlicensed spectrum. This boundary will be referred to below as the "alignment boundary." This alignment boundary can also be aligned with the boundaries of time units in the licensed spectrum.

[0157] Figure 9A The illustration shows three consecutive joint access periods for each TRP accessing multiple unlicensed channels. It should be understood that this embodiment is also applicable to situations where multiple TRPs are multiple panels of the same gNB.

[0158] Figure 9AIt is a combination of a type A-like process in the spatial domain (i.e., per TRP) and a type B-like process in the frequency domain (i.e., per channel). Each TRP independently generates and maintains its own backoff counter according to its corresponding priority level (similar to A1) for use on its selected frequency domain channel. Alternatively, the backoff counter is initialized with the largest CW among all TRPs / panels (similar to A2). p The same random number generated by the distribution. Figure 9A In this process, each TRP attempts to access four channels. For each TRP, one of the four channels is selected as the primary frequency domain channel, while the remaining three are secondary frequency domain channels. The primary frequency domain channel does not need to be the same for every TRP, but it may be. Similarly, the primary frequency domain channel does not need to be different for every TRP, but it may be different. TRPs 904, 906, and 908 communicate with controller 902 to coordinate the t in each joint access period. target And keep the controller and other TRPs notified of failures when accessing one or more channels.

[0159] exist Figure 9A In accordance with TRP1 904, channel 2 is selected as the primary frequency domain channel, while channels 1, 3, and 4 are the secondary frequency domain channels for all three joint access periods. Although in Figure 9A In this situation, the primary frequency channel can be reconfigured so that it is a different channel in subsequent joint access channels. During the first joint access period, the first contention window of CAT4 CCA 910 begins at the start of interval 2. The contention ends at the determined t... target After a backoff occurs between 909 and 911, the CCA interval is 911. target 909 begins at the start of interval 5. Because CAT4 CCA 910 is successful, TRP1904 is transmitted and can receive data on channel 2 within COT 912B ending at BE1. At t targetPrior to 909, for each frequency-domain secondary channel, there are short predefined periods 913A, 913C, and 913D for performing CAT2 CCA on each corresponding secondary channel 1, 3, and 4. CAT2 CCA 913A and 913C are successful for frequency-domain secondary channels 1 and 3, therefore TRP1 904 transmits and can receive data within COT 912A and 912C on channels 1 and 3, respectively. CAT2 CCA 913D is unsuccessful for frequency-domain secondary channel 4, therefore TRP1 904 does not transmit bursts on channel 4 during the first joint access period. The maximum duration of the COT for the frequency-domain secondary channels is the maximum duration of the COT for the frequency-domain primary channel. After the end of COT 912B, a new contention window for CAT4 CCA 914 begins for the second joint access period. After CAT4 CCA 914 is completed, the end of CAT4 CCA 914 coincides with the determined t for the second joint access period. target A new post-retreat CCA interval of 915 exists. target 916 begins at the start of interval 11. Because CAT4 CCA 914 is successful, TRP1 904 is transmitted on channel 2 within COT 917B ending at BE1 and data can be received. In t target Prior to 916, for each frequency domain secondary channel, there were predefined periods 918A, 918C, and 918D for performing CAT2 CCA on each corresponding secondary channel 1, 3, and 4. CAT2 CCA 918A and 918D were successful for frequency domain secondary channels 1 and 4, therefore TRP1 904 transmitted and received data within COT 917A and 917D on channels 1 and 4, respectively. CAT2 CCA 918C was unsuccessful for frequency domain secondary channel 3, therefore TRP1 904 did not transmit / receive data on channel 3 during the second joint access period. After the end of COT 917B, a new contention window for CAT4 CCA 919 began for the third joint access period. After the completion of CAT4 CCA 919, the end of CAT4 CCA 919 coincided with the determination of t for the third joint access period. target A new CCA interval of 920 exists after the backoff at 921. target 921 begins at the start of interval 18. Because CAT4 CCA 919 is successful, TRP1904 is transmitted and data can be received within COT 922B on channel 2. At t targePrior to 921, for each frequency domain secondary channel, there were short predefined periods 923A, 923C, and 923D for performing CAT2 CCA on each corresponding secondary channel 1, 3, and 4. CAT2 CCA 923C was successful for frequency domain secondary channel 3, therefore TRP1 904 could transmit and receive data within COT 922C on channel 3. CAT2 CCA 923A and 923D were unsuccessful for frequency domain secondary channels 1 and 4, therefore TRP1 904 did not transmit / receive data on channels 1 and 4 during the third joint access period.

[0160] Referring to TRP2 906, channel 3 is selected as the primary frequency domain channel, and channels 1, 2, and 4 are secondary frequency domain channels. During the first joint access period, the first contention window for CAT4 CCA 930 begins in interval 2. At the end of CAT4 CCA 930 and t... target After backoff occurs between 909 and 931, CCA interval 931 is reached. Because CAT4 CCA 930 is successful, TRP2 906 is transmitted and received on channel 3 within COT 932C ending at BE2. In t targetPreviously, for each frequency-domain secondary channel, there were short predefined periods 933A, 933B, and 933D for performing CAT2 CCA on each corresponding secondary channel 1, 2, and 4. CAT2 CCA 933A and 933B were successful for frequency-domain secondary channels 1 and 2, so TRP2 906 could transmit and receive data on channels 1 and 2 within COTs 932A and 932B, respectively. CAT2 CCA 933D was unsuccessful for frequency-domain secondary channel 4, so TRP2 906 did not transmit / receive data on channel 4 during the first joint access period. The maximum duration of the COT for the frequency-domain secondary channel is the maximum duration of the data COT (MCOT) for the frequency-domain primary channel. The durations of all channels are not necessarily the same as long as each COT is less than the frequency-domain primary MCOT. After COT 932C ends, a new contention window 934 for CAT4 CCA begins for the second joint access period. CAT4 CCA in contention window 934 is unsuccessful because a signal is detected on that channel. Since CAT4 CCA is unsuccessful, and TRP2 906 will not transmit a burst on the primary frequency channel 3, a backoff CCA interval will not occur. Because the primary frequency channel is considered unavailable to TRP2 906, TRP2 906 will not perform CAT2 CCA procedures on any of the secondary frequency channels 1, 2, and 4 during the second joint access period. TRP2 906 continues iCCA 935 on primary channel 3 until a new contention window for CAT4 CCA 936 begins in the third joint access period. The duration of CAT4 CCA 936 is equal to the remaining portion of the unused counter duration during the second joint access period. After CAT4 CCA 936 is completed, the end of CAT4 CCA 936 coincides with the determined t for the third joint access period. target A new CCA interval of 937 exists after the retreat at 921. target 921 begins at the start of interval 18. Because CAT4 CCA 936 is successful, TRP2 906 sends a burst during COT 938C on channel 3. At t target Prior to 921, for each frequency domain secondary channel, there were short predefined periods 939A, 939B, and 939D for performing CAT2 CCA on each corresponding secondary channel 1, 2, and 4. CAT2 CCA 939B was successful for frequency domain secondary channel 2, therefore TRP2 906 could transmit and receive data within COT 938B on channel 2. CAT2 CCA 939A and 939D were unsuccessful for frequency domain secondary channels 1 and 4, therefore TRP2 906 did not generate / receive bursts on channels 1 and 4 during the third joint access period.

[0161] Referring to TRP3 908, channel 3 is selected as the primary frequency domain channel, while channels 1, 2, and 4 are secondary frequency domain channels. During the first joint access period, the first contention window for CAT4 CCA 940 begins in interval 2. At the end of CAT4 CCA 940 and t... target After backoff occurs between 909 and 941, CCA interval 941 occurs. Because CAT4 CCA 940 is successful, TRP3 908 is transmitted on channel 3 within burst 942C ending at BE3 and data can be received. target Prior to 909, for each frequency-domain secondary channel, there are short predefined periods 943A, 943B, and 943D for performing CAT2 CCA on each corresponding secondary channel 1, 2, and 4. CAT2 CCA 943A, 943B, and 943D are all successful for frequency-domain secondary channels 1, 2, and 4, therefore TRP3 908 transmits and can receive data within COT 942A, 942B, and 942D on channels 1, 2, and 4, respectively. The maximum duration of COT for the frequency-domain secondary channel is the maximum duration of COT for the frequency-domain primary channel. After the end of COT 942C, a new contention window 944 for CAT4 CCA 945 begins for the second joint access period. After CAT4 CCA 945 is completed, at the end of CAT4 CCA 945 and t target A new CCA interval of 946 exists after the backoff at 916. target 916 begins at the start of interval 11. Because CAT4 CCA 945 is successful, TRP3 908 is transmitted within burst 947B on channel 3 and data can be received. In t targetPrior to 916, for each frequency-domain secondary channel, there were short predefined periods 948A, 948B, and 948D for performing CAT2CCA on each corresponding secondary channel 1, 2, and 4. CAT2 CCA 948A and 948D were successful for frequency-domain secondary channels 1 and 4, therefore TRP3 908 could transmit and receive data within COT 947A and 947D on channels 1 and 4, respectively. CAT2CCA 948B was unsuccessful for frequency-domain secondary channel 2, therefore TRP3 908 did not transmit / receive bursts on channel 2 during the second joint access period. After the COT duration 947C ended, a new contention window 949 for CAT4 CCA began for the third joint access period. CAT4 CCA in contention window 949 was unsuccessful because the channel was sensed as busy. Similar to TRP2 906 in the second joint access period, because CAT4 CCA was unsuccessful, it is not transmitted on frequency domain primary channel 3 or any frequency domain secondary channels 1, 2, and 4 in the third joint access period. TRP3 908 continues iCCA on frequency domain primary channel 3 until a new contention window begins for the remaining duration of the unused CAT4 CCA 936 process in the third joint access period.

[0162] Figure 9B It shows the relationship with Figure 9A Similarly, and added based on the modified t target An example of backtracking early alignment with start time. Figure 9B The first joint visit period and Figure 9A The same as shown. In Figure 9B During the second joint access period, CW 960, used for the frequency domain master channel (channel 3), is the longest spatial domain master channel among the three TRPs. The CAT4 CCA 962 executed in CW 960 failed. As a result, TRP2 906 sent a missed t to controller 902. target Notification. In some embodiments, the notification is also sent to TRP1 904 and TRP3 908. In other embodiments, TRP1 904 and TRP3 908 do not receive the notification from TRP2 906, but receive it from controller 902. Controller 902 is able to determine the time difference between the original schedule and the time difference. target 966 earlier t target 964, because the original scheduler's t target 966 is based on the longest CW associated with TRP2 906. Because TRP2 906 will miss the original schedule's t... target 966 and the original schedule t target 966 depends on CW2 960, if controller 902 has enough time to coordinate the modified t targetIf 964, then TRP1 904 and TRP3 908 do not need to wait for the original schedule's t. target 966. The t that needs to be modified. target 964 will depend on the second long CW between TRP1 904 and TRP3 908.

[0163] In some embodiments, the transmission power of each TRP that successfully accesses a channel can be reduced based on the number of TRPs transmitting simultaneously and the number of idle frequency channels for each TRP.

[0164] In some embodiments, coordinating the start point of channel access procedures on different frequency primary channels across TRP results in the alignment of transmission start times for each unlicensed channel used for multi-channel access attempts.

[0165] In some embodiments, when t target When based at least on the latest BE and the maximum CW of multiple TRPs, a delay in CCA due to mutual blanking of longer COTs is provided during subsequent joint access attempts. If a TRP performs the channel access procedure independently rather than jointly with other TRPs, the potential alignment of the TRP's transmission can be at the same or slightly later than the earliest possible start point. target occur.

[0166] In some embodiments, CAT2 CCA is used on the secondary frequency channel of each TRP to avoid blanking of wideband (WB) joint TRP channel access opportunities due to one or more coexisting subband transmissions.

[0167] In some embodiments, applying A1-type or A2-type rules in the spatial domain to generate backoff counters for the primary channel improves coexistence fairness with other nodes from the same or different radio access technologies (RATs).

[0168] Figure 10A 10B and 10C show two consecutive joint access periods for each TRP or panel to access multiple unlicensed channels. Figure 10A , 10B Each of 10C is a combination of a type A process in the spatial domain and a type A process in the frequency domain. Each TRP independently generates and maintains its own backoff counter for wideband (WB) CCA on its wideband CC or bandwidth part (BWP) (similar to type A1).

[0169] exist Figure 10AIn this process, each TRP attempts to access four channels. Each TRP initiates a wideband (WB) CCA process on all four channels, at least until a busy state is detected on one of the channels. If a busy state is detected, the TRP can switch to CAT4 CCA, i.e., subband CCA, for each channel to avoid compromising the overall transmission opportunity. Even if a busy state is detected on one of the channels, one or more channels can still have a successful CAT4 CCA result. TRPs 1004, 1006, and 1008 communicate with controller 1002 to coordinate the process. target And keep the controller and other TRPs notified of failure when accessing one or more channels.

[0170] exist Figure 10A Referring to TRP1 1004, during the first joint access period, the first contention window of WB CCA 1010 begins at the start of interval 1. WB CCA 1010 is successful because an idle state is detected for all four channels. At the end of WB CCA 1010 and the determined t... target A self-deferred interval 1011 occurs between 1009 and 1009. At t... target Prior to 1009, for each channel, there are short, predefined periods 1012A, 1012B, 1012C, and 1012D for performing CAT2 CCA on each corresponding channel. CAT2 CCA 1012B and 1012C are successful for channels 2 and 3, therefore TRP1 1004 transmits and receives data within COT 1013B and 1013C with duration BE1 on channels 2 and 3, respectively. CAT2 CCA 1012A and 1012D are unsuccessful for channels 1 and 4, therefore TRP1 1004 does not transmit / receive bursts on channels 1 and 4 during the first joint access period.

[0171] Also during the first joint access period, TRP2 1006 performs WB CCA 1030. For example, TRP2 1006's WB CCA 1030 fails due to a detected transmission on channel 4. Although the transmission detected by TRP2 1006 is on channel 4, it should be understood that TRP may not know which channel(s) caused the failure. As a result, TRP2 1006 switches to CAT4 CCA 1031A, 1031B, 1031C, and 1031D for each individual channel. When WB CCA switches to multiple individual subband CCAs, the remaining value of the WB backoff counter is used for the subband backoff counter. This is similar to type A2 in the frequency domain. When a "CCA failure" of CAT4WB is detected in a given CCA slot, TRP switches to subband CCA. If a WB CCA failure occurs before the latest BE, a switch to subband CCA may not be triggered because WB CCA failures are attributed to mutual blanking.

[0172] TRP2 1006 notifies controller 1002, TRP1 1004, and TRP3 1008 of the failure. Because the failure and notification occur after TRP1 1004 completes its WB CCA 1010, this has no impact on TRP1 1004's WB CCA operation. However, TRP3 1008 has not yet completed its WB CCA 1060, so TRP3 1008 switches to CAT4 CCA for each individual channel to avoid the possibility of compromising the overall transmission opportunity. Cross-TRP indications can be sent, for example, via the controller, to other TRPs within the same group to switch from WB CCA to sub-band CCA. The switchover can also follow preset rules, such as always using WB CCA for the CAT4 backoff process, while the sub-band CCA is always CAT2 before transmission begins.

[0173] TRP2 1006 performs CAT4 CCA procedures 1031A, 1031B, 1031C, and 1031D for each of channels 1 through 4. CAT4 CCA 1031A, 1031B, and 1031C are successful for channels 1 through 3, while CAT4 CCA 1031D is unsuccessful for channel 4. At the end of the CAT4 CCA for each channel and t... target A self-deferred interval of 1032 occurs between 1009 and 1009. At t targetPrior to 1009, for each channel, there are short predefined periods 1033A, 1033B, 1033C, and 1033D for performing CAT2 CCA on each corresponding channel. CAT2 CCA 1033B and 1033C are successful for channels 2 and 3, therefore TRP2 1006 transmits and receives data within COT 1034B and 1034C at the end of BE2 on channels 2 and 3, respectively. CAT2 CCA 1033A and 1033D are unsuccessful for channels 1 and 4, therefore TRP2 1006 does not generate / receive bursts on channels 1 and 4 during the first joint access period.

[0174] Also during the first joint access period, TRP3 1008 initially executes WB CCA 1060. When TRP3 1008 notifies TRP3 1008 of the failure of WB CCA 1030, TRP3 1008 switches to CAT4 CCA 1061A, 1061B, 1061C, and 1061D for each individual channel. TRP3 1008 completes CAT4 CCA procedures 1061A, 1061B, 1061C, and 1061D for each of channels 1 through 4, respectively. CAT4 CCA 1061A, 1061B, and 1061C are successful for channels 1 through 3, while CAT4 CCA 1061D is unsuccessful for channel 4. At the end of CAT4 CCA and t target A self-deferred interval of 1062 occurs between 1009 and 1009. At t target Prior to 1009, for each channel, there are short, predefined periods 1063A, 1063B, 1063C, and 1063D for performing CAT2 CCA on each corresponding channel. CAT2 CCA 1063A, 1063B, and 1063C are successful for channels 1, 2, and 3, therefore TRP3 1008 transmits and receives data on channels 1, 2, and 3 within COT 1064A, 1064B, and 1064C ending at BE3, respectively. CAT2 CCA 1063D is unsuccessful for channel 4, therefore TRP3 1008 does not transmit / receive bursts on channel 4 during the first joint access period.

[0175] Referring again to TRP3 1008, after the completion of COT 1064A, 1064B, and 1064C on channels 1, 2, and 3, a new contention window 1065 for WBCCA 1066 begins for the second joint access period. TRP3 1008 executes WBCCA 1066. WBCCA 1066 fails because a signal is detected on channel 2. As a result, TRP3 1008 switches to CAT4CCA 1067A, 1067B, 1067C, and 1067D for each individual channel. TRP3 1008 notifies controller 1002, TRP1 1004, and TRP2 1006 of the failure. TRP1 and TRP2 1008 failed to complete their WB CCA 1015 and 1036, therefore TRP1 1002 and TRP2 1006 switched to CAT4 CCA for each individual channel to mitigate the possibility that all channels would be indicated as unavailable when some channels were actually still available. TRP3 1008 completed CAT4 CCA procedures 1067A, 1067B, 1067C, and 1067D for each of channels 1 through 4, respectively. CAT4 CCA 1067A, 1067C, and 1067D were successful for channels 1, 2, and 4, while CAT4 CCA 1067C was unsuccessful for channel 3. At the end of the CAT4 CCA and t target A self-delayed interval of 1068 occurs between 1055 and 1055. At t... target Prior to 1055, for each channel, there are short, predefined periods 1069A, 1069B, 1069C, and 1069D for performing CAT2 CCA on each corresponding channel. CAT2 CCA 1069A, 1069C, and 1069D are successful for channels 1, 3, and 4, therefore TRP3 1008 transmits and receives data within COT 1070A, 1070C, and 1070D on channels 1, 3, and 4, respectively. CAT2 CCA 1069B is unsuccessful for channel 2, therefore TRP3 1008 does not transmit / receive bursts on channel 2 during the second joint access period.

[0176] Returning to TRP2 1006, after the completion of COT 1034B and 1034C on channels 2 and 3, a new contention window 1035 for WB CCA 1036 begins for the second joint access period. TRP2 1006 initiates WB CCA 1036. As a result of receiving the WB CCA failure notification from TRP3 1008, TRP2 1006 switches to CAT4 CCA 1037A, 1037B, 1037C, and 1037D for each individual channel. CAT4 CCA procedures 1037A, 1037B, 1037C, and 1037D are unsuccessful for channels 1, 2, 3, and 4, respectively, therefore TRP2 1006 does not transmit / receive bursts on any channel during the second joint access period.

[0177] Returning to TRP1 1004, after the completion of COT 1013B and 1013C for channels 2 and 3, a new contention window 1014 for WB CCA 1015 begins for the second joint access period. As a result of receiving the WB CCA failure notification from TRP3 1008, TRP1 1004 switches to CAT4 CCA 1016A, 1016B, 1016C, and 1016D for each individual channel. TRP1 1004 completes the CAT4 CCA procedures 1016A, 1016B, 1016C, and 1016D for each of channels 1 through 4, respectively. CAT4 CCA 1016A and 1016D are successful for channels 1 and 4, while CAT4 CCA 1016B and 1016C are unsuccessful for channels 2 and 3, respectively. At the end of CAT4 CCA and t target A self-delayed interval of 1017 occurs between 1055 and 1017. At t... target Prior to 1055, for each channel, there are short predefined periods 1018A, 1018B, 1018C, and 1018D for performing CAT2 CCA on each corresponding channel. CAT2 CCA 1018A and 1018D are successful for channels 1 and 4, therefore TRP1 1004 transmits and receives data within COT 1019A and 1019D on channels 1 and 4, respectively. CAT2 CCA 1018B and 1018C are unsuccessful for channels 2 and 3, therefore TRP1 1004 does not generate / receive bursts on channels 2 and 3 during the second joint access period.

[0178] Figure 10B It shows the relationship with Figure 10ASimilar examples exist. However, except for the existence of self-delayed 1032 between WB CCA 1010 and CAT2 CCA 1012A, 1012B, 1012C and 1012D, or between individual subbands CCA 1031A, 1031B, 1031C and 1031D and CAT2 CCA 1033A, 1033B, 1033C and 1033D, as in Figure 10A As in the example of the first joint access period of TRP1 1008 and TRP2 1006, in Figure 10B In the middle, WB CCA or a separate sub-band CCA in t target It ends and does not have CAT2. There is also a pre-CCA delay period before the start of WB CCA for each TRP in each joint access period.

[0179] Reference Figure 10B During the first joint access period, for each TRP, WBCCA is performed after the pre-CCA delay period. TRP2 1006's WBCCA fails, and TRP2 1006, for example, sends a cross-TRP indication via the controller. Therefore, both TRP1 1004 and TRP3 1008 switch to sub-band CCA. Each sub-band CCA starts from the same backoff counter, so CCA occurs simultaneously at t target Finish.

[0180] During the second joint access period, all three TRPs begin with WB CCA, but they again transition to subband CCA as in the first joint access period. Subband CCA is unsuccessful for all channels of TRP2 1006, therefore TRP2 1006 does not access any channels during the second joint access period. TRP2 1006 notifies controllers 1002, TRP1 1004, and TRP8 1008 of the missed channels. target Therefore, the initial scheduling t target The start time was modified to an earlier one. The initial scheduling time t target This depends on BE1 of TRP1 1004 and CW2 of TRP2 1006. The controller can then be configured with reference to... Figure 6A The similar approach described is based on the second-longest CW to determine the modified t. target .

[0181] During the third joint access period, TRP1 1004 and TRP 3 1008 perform WB CCA, and TRP2 1006 performs subband CCA instead of WB CCA until t targetBecause its access is blanked during the second joint access period. The duration of the subband CCA performed by TRP2 1006 can be equal to the remainder of the counter duration of the CW from the start of the second joint access period when the subband CCA is frozen when busy conditions are detected on four channels.

[0182] Figure 10C An example of using WB CCA is shown, and it also involves what happens when t is missed due to CCA failure. target When using backoff, CCA and TRP are sent to the missed t target The notification. Figure 10C In addition, the notification also resulted in the original schedule's t being removed during the second joint access period. target Modify t target .

[0183] exist Figure 10C During the first joint access period, for TRP 1 1004, WB CCA 1070 was successfully completed, after which WB CCA 1071 began after backoff. WB CCA 1071 failed after backoff, therefore switching to backoff subbands CCA 1072A, 1072B, 1072C, and 1072D. When WB CCA 1071 failed, TRP1 1004 sent a failure notification to controllers 1002, TRP2 1006, and TRP3 1008. Upon receiving the notification from TRP1 1004, TRP2 1006 had already completed WB CCA 1080 and was currently performing backoff WB CCA. Then, TRP2 1006 switches from the backoff WBCCA to the backoff subband CCAs 1082A, 1082B, 1082C, and 1082D. Upon receiving notification from TRP1 1004, TRP3 1008 has not yet completed WB CCA 1090, therefore TRP3 1008 switches from WB CCA 1090 to subband CCAs 1091A, 1091B, 1091C, and 1091D. When the subband CCA is complete, TRP3 1008 executes the backoff subband CCAs 1092A, 1092B, 1092C, and 1092D. Each backoff subband CCA of the three TRPs is executed within the t period used for the first joint access. target Finish.

[0184] During the second joint access period, all three TRPs begin with WB CCA, but they revert to subband CCA. WB CCA 1085 is unsuccessful for all channels of TRP2 1006, therefore TRP2 1006 does not access any channels during the second joint access period. The initial scheduling t targetIt was also modified to an earlier start time. The initial scheduling time t target This depends on BE1 of TRP1 1004 and CW2 of TRP2 1006. Subband CCA is unsuccessful for TRP2 1006, and TRP2 1006 notifies controllers 1002, TRP1 1004, and TRP8 1008 of the missed t. target Then, the controller can refer to Figure 6A The similar approach described is based on the second-longest CW to determine the modified t. target .

[0185] For TRP1 1004, during the second joint access period, TRP1 1004 receives the missed t from TRP2 1006. target Notification. TRP1 1004 does not require a basis for receiving missed t. target The notification indicates a switch from backoff WB CCA 1074 to backoff subband CCA. However, detected signals on channels 2 and 3 cause TRP1 1004 to switch from WB backoff CCA 1074 to subband backoff CCA 1075A, 1075B, 1075C, and 1075D. Busy states detected on channels 2 and 3 prevent TRP1 1004 from accessing channels 2 and 3.

[0186] For TRP3 1008, during the second joint access period, TRP3 1008 receives the missed t from TRP2 1006. target Notification. TRP3 1008 is still in WB CCA 1094, but not based on the received missed t target The notification switches from WBCCA 1094 to subband CCA. However, a detected signal exists approximately simultaneously on channel 2, causing TRP3 1008 to switch from WBCCA 1094 to subband CCA 1095A, 1095B, ​​1095C, and 1095D. When subband CCA is complete, subband backoff CCA 1096A, 1096B, 1096C, and 1096D are executed until the modified t target The busy state detected on channel 2 prevented TRP3 1008 from accessing channel 2.

[0187] In some embodiments, using WB CCA as the default backoff process for each TRP, compared to subband LBT, reduces the complexity and energy consumption of LBT.

[0188] In some embodiments, switching to subband CAT4 or CAT2 on the secondary frequency channel of each TRP avoids blanking WB joint TRP channel access opportunities due to one or more coexisting subband transmissions.

[0189] In some embodiments, coordinating the start points of channel access procedures on different frequency primary channels of multiple TRPs results in the alignment of the transmission start time for each unlicensed channel in a multi-channel access attempt.

[0190] In some embodiments, when t target When based on at least the latest BE of multiple TRPs and the maximum CW of multiple TRPs, the delay in CCA caused by the mutual blanking of longer COTs is provided in subsequent joint access attempts.

[0191] In some embodiments, applying A1-type or A2-type rules in the spatial domain to generate backoff counters for the primary channel improves coexistence fairness with other nodes from the same or different RATs.

[0192] Figure 11A This illustrates two consecutive joint access periods for each TRP or panel to access multiple unlicensed channels. Figure 11A It is a combination of type B-like processes in the spatial domain and type B-like processes in the frequency domain. Figure 11A In this configuration, each TRP attempts to access four channels. One TRP in the TRP group is selected as the spatial domain primary TRP for at least one joint access period, while the remaining two TRPs are spatial domain secondary TRPs for the corresponding number of joint access periods. The spatial domain primary TRPs do not need to be the same for all joint access periods. The spatial domain primary TRP can independently generate and maintain its own backoff counter based on its corresponding priority level. p The distribution generation is similar to that of frequency domain type B2.

[0193] TRPs 1104, 1106, and 1108 communicate with controller 1102 to transmit t target It relies solely on the spatial domain master TRP and keeps the controller and other TRPs notified of failures when accessing one or more channels.

[0194] exist Figure 11A In this configuration, TRP1 1104 is selected as the spatial domain master TRP for both the first and second joint access periods. In another embodiment, instead of coordinating the start time, a cross-TRP backoff success indication sent by the controller via TRP1 1104 is used. Based on random selection of TRPs within the TRP group, based on polling, or based on the first TRP, a TRP can be selected as the spatial domain master TRP. This may cause other TRPs to terminate their own CAT4 CCA and relinquish their corresponding remaining CW. The first TRP completes its CAT4 CCA on its primary frequency channel, indicating that it is the master TRP for the current joint access period.

[0195] During the first joint access period, the first contention window for CAT4 CCA 1110 begins on the primary frequency channel within interval 2. The primary frequency channel is channel 2 (CH2). TRP1 1104 notifies controllers 1102, TRP2 1106, and TRP3 1108 of the successful completion of the CAT4 CCA procedure. The CAT4 CCA 1110 ends with the determined t... target A self-delayed interval 1111 occurs between 1109. At t... target Prior to 1109, for each channel, there are short, predefined periods 1112A, 1112B, 1112C, and 1112D for performing CAT2 CCA on each corresponding channel. CAT2 CCA 1112A, 1112B, and 1112C are successful for channels 1, 2, and 3, therefore TRP1 1104 transmits and can receive data within COT 1113A, 1113B, and 1113C on channels 1, 2, and 3, respectively. CAT2 CCA 1112D is unsuccessful for channel 4, therefore TRP1 1104 does not generate / receive bursts on channel 4 during the first joint access period.

[0196] For TRP2 1106, also during the first joint access period, in t target Prior to 1109, for each channel, there are short, predefined periods 1130A, 1130B, 1130C, and 1130D for performing CAT2 CCA on each corresponding channel. CAT2 CCA 1130A, 1130B, and 1130C are successful for channels 1, 2, and 3, therefore TRP2 1106 transmits and receives data within COT 1131A, 1131B, and 1131C on channels 1, 2, and 3, respectively. CAT2 CCA 1130D is unsuccessful for channel 4, therefore TRP2 1106 does not transmit / receive bursts on channel 4 during the first joint access period.

[0197] For TRP3 1108, also during the first joint access period, in t target Prior to 1109, for each channel, there were short, predefined periods 1160A, 1160B, 1160C, and 1160D for performing CAT2 CCA on each corresponding channel. CAT2 CCA 1160A, 1160B, 1160C, and 1160D were successful for channels 1, 2, 3, and 4, therefore TRP31108 could transmit and receive data within COT 1161A, 1161B, 1161C, and 1161D on channels 1, 2, 3, and 4, respectively.

[0198] In the second joint access period, TRP1 1104 is still selected as the space domain master TRP. The first contention window for CAT4 CCA1114 begins after COT 1113B of the first joint access period. At the end of CAT4 CCA 1114 and t target A self-delayed interval 1116 occurs between 1125 and t. target Prior to 1125, for each channel, there are short predefined periods 1117A, 1117B, 1117C, and 1117D for performing CAT2 CCA on each corresponding channel. CAT2 CCA 1117A, 1117B, and 1117D are successful for channels 1, 2, and 4, therefore TRP1 1104 transmits and can receive data within COT1118A, 1118B, and 1118D on channels 1, 2, and 4, respectively. CAT2 CCA 1117C is unsuccessful for channel 3, therefore TRP1 1104 does not transmit / receive bursts on channel 3 during the second joint access period. A new contention window 1120 exists as part of the third joint access period. CAT4 CCA shows no failure within contention window 1120.

[0199] Referring to TRP2 1106, after the COT 1131A, 1131B, and 1131C of channels 1, 2, and 3 have ended, TRP2 1106 remains idle relative to access, transmission, or reception on unlicensed channels until t target Before 1125. In t target Prior to 1125, for each channel, there are short predefined periods 1135A, 1135B, 1135C, and 1135D for performing CAT2 CCA on each corresponding channel. CAT2 CCA 1135A and 1135B are successful for channels 1 and 2, therefore TRP2 1106 transmits and receives data within COT 1137A and 1137B on channels 1 and 2, respectively. CAT2 CCA 1135C and 1135D are unsuccessful for channels 3 and 4, therefore TRP2 1106 does not transmit / receive bursts on channels 3 and 4 during the second joint access period.

[0200] Referring to TRP3 1108, after the COT 1161A, 1161B, 1161C, and 1161D of channels 1, 2, 3, and 4 have ended, TRP3 1108 remains idle relative to access, transmission, or reception on unlicensed channels until t target Before 1125. In t targetPrior to 1125, for each channel, there are short predefined periods 1164A, 1164B, 1164C, and 1164D for performing CAT2 CCA on each corresponding channel. CAT2 CCA 1164A, 1164C, and 1164D are successful for channels 1, 3, and 4, therefore TRP3 1108 transmits and receives data within COT 1165A, 1165C, and 1165D on channels 1, 3, and 4, respectively. CAT2 CCA 1164B is unsuccessful for channel 2, therefore TRP3 1108 does not transmit / receive bursts on channel 2 during the second joint access period.

[0201] Figure 11B The description concerns the use of three antenna panels associated with and controlled by the gNB, in contrast to multiple TRPs controlled by a controller, such as... Figure 11A As in the example. However, it should be understood that the same process can be applied to multiple TRPs coordinated by a controller, or to multiple antenna panels across multiple TRPs. Figure 11B In this context, the main panel of the spatial domain is designated, while the remaining panels are designated as secondary panels of the spatial domain. Figure 11B In the case of the first joint access period, instead of a pre-selected panel as the main panel of the spatial domain, panel 1 1154 completes WB CCA 1160 before WB CCA 1170 and 1180 of the other two panels 1156 and 1158, and therefore sends a notification to gNB 1150, panel 2 1156, and panel 3 1158, designating itself as the main panel of the spatial domain. Additionally, this notification causes WB CCA 1170 and 1180 to be performed by panel 1 1154 during the first joint access period. target Truncation occurs before 1168. Therefore, all three panels have the same t. target It can be used in conjunction with the original schedule of panel 2 1156 and panel 3 1158. target different.

[0202] When panel 1 1154 completes WB CCA 1160, there is a short self-delay period 1161. Subbands CAT2 CCA 1162A, 1162B, 1162C, and 1162D occur after self-delay period 1161 and t target End of 1168.

[0203] exist Figure 11B In the example, if a channel on the main spatial domain panel is found to be inaccessible, that channel is also considered inaccessible to the secondary spatial domain panels. This is related to truncation of WB CCA 1170 and 1180. targetDuring the brief period between 1168, both panel 2 1156 and panel 3 1158 switched from WB CCA to CAT2 subband CCA.

[0204] During the second joint access period, the WB CCA 1174 of the spatial domain auxiliary panel 2 1156 fails before the counter reaches zero, while the spatial domain auxiliary panel 3 1158 completes the WB CCA 1184 first. Panel 3 1158 sends a notification to gNB 1150, designating itself as the spatial domain master panel. In some embodiments, panel 1158 sends this notification to panels 1 1154 and 2 1156. In other embodiments, gNB 1150 sends this notification to panels 1 1154 and 2 1156. target Before 1178, switch to sub-band CCA 1185A, 1185B, 1185C, and 1185D. Panel 3 1158 senses that channel 2 is busy and therefore unavailable, but senses that channels 1, 3, and 4 are accessible.

[0205] Similarly, during the second joint access period, spatial domain panel 1 1154 receives notification that spatial domain panel 3 is the new spatial domain master panel and switches to subbands CAT2 CCA 1165A, 1165B, 1165C, and 1165D. Panel 1 1154 senses that channel 2 is busy and therefore unavailable, but senses that channels 1, 3, and 4 are accessible.

[0206] Similarly, during the second joint access period, spatial domain panel 2 1156 receives notification from spatial domain panel 3 1158 that it is the new spatial domain master panel and switches to subbands CCA 1175A, 1175B, 1175C, and 1175D. Panel 2 1156 senses that channels 2 and 3 are busy and therefore unavailable, but senses that channels 1 and 4 are accessible.

[0207] In some embodiments, a type B-like process is employed in both the spatial and frequency domains to provide fast, low-complexity joint TRP access to multiple channels, wherein the t-term of the current joint access period is reduced. target The computation and coordination are crucial, but this comes at the cost of a higher blanking probability due to reliance on a single channel. However, Figure 11B The implementation mitigates the latter problem by employing WB CAT4 CCA on the spatial domain master panel and switching each channel to subband CAT2 CCA before the transmission start time, especially when WB CCA fails in the CCA slot. Thus, channel access for each unlicensed channel by the spatial domain secondary panel depends on the spatial domain master CCA result on the corresponding unlicensed channel, in addition to their respective CAT2 CCA.

[0208] In another embodiment of joint multichannel access using spatial domain type B (not captured in the figure), self-delaying periods and CAT2 CCA may not be required after a successful WB or subband CAT4 CCA of the spatial domain primary TRP. Instead, the spatial domain primary TRP can immediately fill the time gap (if any) with micro-slots / partial subframes and / or cyclic prefix (CP) extensions upon successful WB or subband CAT4 CCA, up to the earliest alignment boundary, thus initiating transmission. In this case, CAT2 CCA of the spatial secondary TRP is performed so that it ends at the transmission start point of the spatial domain primary TRP, for example, based on prior knowledge of the spatial domain primary TRP's CW period or backoff counter value.

[0209] Due to more efficient backhaul communication, embodiments consistent with those described in Figure 11 may be particularly suitable for in-station panels of the same gNB.

[0210] In some embodiments, applying a B-type process in the spatial domain to generate the backoff counter for the primary channel can improve coexistence fairness with other nodes from the same or different RATs.

[0211] Figure 12 Two consecutive joint access periods are illustrated for each TRP or panel accessing multiple unlicensed channels, each showing a different embodiment of a combination of a type B-like process in the spatial domain and a type A-like process in the frequency domain. The first joint access period shows a first example of combining a type B-like process in the spatial domain with a type A-like process in the frequency domain, while the second joint access period shows a second example of combining a type B-like process in the spatial domain with a type A-like process in the frequency domain. Figure 12 In this process, each TRP attempts to access four channels. Each channel is selected to have a spatial domain master TRP. TRPs 1204, 1206, and 1208 communicate with controller 1202 to coordinate the process. target And keep the controller and other TRPs notified of failure when accessing one or more channels.

[0212] During the first joint access period, the various channels have different t values. target Time, which means the t target They are not necessarily aligned with each other because the backoff counters of the spatial domain master TRP for each channel are generated and maintained independently of their respective distributions. The maintenance and adjustment of CW on a given frequency channel can be based at least on the HARQ-ACK values ​​corresponding to the reference slots / subframes of all spatial transmissions on the corresponding channel.

[0213] exist Figure 12In the two joint access periods, TRP1 1204 is selected as the spatial domain master TRP for channels 2 and 3. In two separate example joint access periods, TRP2 1206 is selected as the spatial domain master TRP for channel 1. In two separate example joint access periods, TRP3 1208 is selected as the spatial domain master TRP for channel 4. For each joint access period, it is not necessary to maintain the spatial domain master TRP for the same channel, because the spatial domain master TRP for a given channel can be reconfigured for different joint access channels.

[0214] During the first joint access period, for TRP1 1204 and channels 2 and 3, the first contention window of WB CCA 1210 begins within interval 2. WB CCA is used in this case because channels 2 and 3 are adjacent to each other. At the end of WB CCA 1210, the determined t... targetCH2 / CH3 A self-deferred interval 1211 occurs between 1209 and 1209. targetCH2 / CH3 1209 starts in interval 4. Because WB CCA 1210 was successful, at t targetCH2 / CH3 Prior to 1209, for each of channels 2 and 3, there are short predefined periods 1212B and 1212C for performing CAT2 CCA on each of channels 2 and 3, respectively. CAT2 CCA 1212B and 1212C are successful, therefore TRP1 1204 can transmit and receive data within COT 1213B and 1213C on each of channels 2 and 3, respectively.

[0215] For TRP2 1206 and channels 2 and 3, in t targetCH2 / CH3 Prior to 1209, for each of channels 2 and 3, there are short predefined periods 1232B and 1232C for performing CAT2 CCA on each of channels 2 and 3, respectively. CAT2 CCA 1232B and 1232C are successful, therefore TRP2 1206 transmits and receives data within COT 1233B and 1233C on each of channels 2 and 3, respectively.

[0216] For TRP3 1208 and channels 2 and 3, in t targetCH2 / CH3 Prior to 1209, for each of channels 2 and 3, there are short predefined periods 1262B and 1262C for performing CAT2 CCA on each of channels 2 and 3, respectively. CAT2 CCA 1262B and 1262C are successful, therefore TRP3 1208 transmits and receives data within COT 1263B and 1263C on each of channels 2 and 3, respectively.

[0217] Similarly, during the first joint access period, for TRP2 1206 and channel 1, the first contention window 1230 of CAT4 CCA 1230A begins at the start of interval 1. CAT4 CCA 1230A is unsuccessful because a signal is detected on channel 1. At the end of CAT4 CCA 1230A and t... targetCH1 A self-deferred interval 1231 occurs between 1219. targetCH1 1219 starts in interval 3. In t targetCH1 Prior to 1219, for channel 1, there was a short, predefined period 1236 during which CAT2 CCA was performed on channel 1. CAT2 CCA was unsuccessful, therefore no transmission / reception occurred because channel 1 was considered unavailable.

[0218] For TRP1 1204 and channel 1, at t targetCH1 Prior to 1219, for channel 1, there was a short, predefined period 1214 during which CAT2 CCA was performed. CAT2 CCA was unsuccessful, therefore no transmission / reception occurred because channel 1 was considered unavailable.

[0219] For TRP3 1208 and channel 1, at t targetCH1 Prior to 1219, for channel 1, there was a short, predefined period 1264 for performing CAT2 CCA. CAT2 CCA was unsuccessful, therefore no transmission / reception occurred because channel 1 was considered unavailable.

[0220] Similarly, during the first joint access period, for TRP3 1208 and channel 4, the first contention window for CAT4 CCA 1260 begins before interval 1. At the end of CAT4 CCA 1260 and t... targetCH4 A self-deferred interval 1261 occurs between 1229. At t... targetCH4 Prior to 1229, for channel 4, there is a short predefined period 1262 during which CAT2 CCA is performed on channel 4. CAT2 CCA 1262 is successful for channel 4, therefore TRP3 1208 is transmitted and data can be received within COT 1263 on channel 4.

[0221] For TRP1 1204 and channel 4, at t targetCH4 Prior to 1229, for channel 4, there is a short predefined period 1215 for performing CAT2 CCA. CAT2 CCA is successful, therefore TRP1 1204 is transmitted within COT 1216 on channel 4 and data can be received.

[0222] For TRP2 1206 and channel 4, at t targetCH4Prior to 1229, for channel 4, there is a short predefined period 1234 for performing CAT2 CCA. CAT2 CCA is successful, therefore TRP2 1206 is transmitted within COT 1235 on channel 4 and data can be received.

[0223] In the second joint visit period, instead of having different t target For various channels, all channels share the same target time because the backoff counter for the spatial domain master TRP is generated and maintained according to a single distribution. Therefore, for various channels, t target Alignment. The maintenance and adjustment of this public CW can be based at least on the HARQ-ACK value corresponding to the reference time slot / subframe for all space-frequency transmissions.

[0224] During the second joint access period, for TRP1 1204 and channels 2 and 3, the first contention window of WB CCA 1220 begins at the start of interval 11. At the end of WB CCA 1220 and the determined t... target A self-delayed interval 1221 occurs between 1239. Target 1239 begins in interval 13. Because WB CCA 1220 is successful, prior to target 1239, for each of channels 2 and 3, there are short predefined periods 1222B and 1222C for performing CAT2 CCA on each of channels 2 and 3. CAT2 CCA 1222B and 1222C are successful, therefore TRP1 1204 is transmitted and can receive data within COT1223B and 1223C on each of channels 2 and 3, respectively.

[0225] For TRP2 1206 and channels 2 and 3, in t target Prior to 1239, for each of channels 2 and 3, there are short predefined periods 1242B and 1242C for performing CAT2 CCA on each of channels 2 and 3, respectively. CAT2 CCA 1242B and 1242C are successful, therefore TRP2 1206 can transmit and receive data within COT 1243B and 1243C on each of channels 2 and 3, respectively.

[0226] For TRP3 1208 and channels 2 and 3, in t target Prior to 1239, for each of channels 2 and 3, there are short predefined periods 1265B and 1265C for performing CAT2 CCA on each of channels 2 and 3, respectively. CAT2 CCA 1265B and 1265C are successful, therefore TRP3 1208 transmits and receives data within COT 1268B and 12638 on each of channels 2 and 3, respectively.

[0227] Similarly, during the second joint access period, for TRP2 1206 and channel 1, the first contention window 1240 of CAT4 CCA 1240A begins at the start of interval 11. CAT4 CCA 1240A is unsuccessful because a signal was detected on channel 1. At the end of CAT4 CCA 1240A and t... target A self-deferred interval 1241 occurs between 1229. target 1239 begins in interval 13. Before target 1239, for channel 1, there is a short predefined period 1246 during which CAT2 CCA is performed on channel 1. CAT2 CCA is unsuccessful, therefore no transmission / reception occurs because channel 1 is considered unavailable.

[0228] For TRP1 1204 and channel 1, at t target Before 1239, for channel 1, there is a short predefined period 1224 during which CAT2 CCA is performed. CAT2 CCA is unsuccessful, therefore no transmission or reception occurs because channel 1 is considered unavailable.

[0229] For TRP3 1208 and channel 1, at t target Prior to 1239, for channel 1, there is a short, predefined period 1267 for performing CAT2 CCA. CAT2 CCA is unsuccessful, therefore no transmission / reception occurs because channel 1 is considered unavailable.

[0230] Similarly, during the second joint access period, for TRP3 1208 and channel 4, the first contention window of CAT4 CCA 1270 begins in interval 11. The end of CAT4 CCA 1270 coincides with t... target A self-deferred interval 1271 occurs between 1239. At t... target Prior to 1239, for channel 4, there is a short predefined period 1272 during which CAT2 CCA is performed on channel 4. CAT2 CCA 1272 is successful for channel 4, therefore TRP3 1208 is transmitted and data can be received within COT 1273 on channel 4.

[0231] For TRP1 1204 and channel 4, at t target Prior to 1239, for channel 4, there is a short predefined period of 1225 for performing CAT2 CCA. CAT2 CCA is successful, therefore TRP1 1204 is transmitted within COT 1226 on channel 4 and data can be received.

[0232] For TRP2 1206 and channel 4, at ttarget Prior to 1239, for channel 4, there is a short, predefined period 1244 during which CAT2 CCA is performed. CAT2 CCA is successful, therefore TRP2 1206 transmits and may receive data within COT 1245 on channel 4.

[0233] In some embodiments of this application, a method is provided for a Transmitting Receiver Point (TRP) to jointly access one or more unlicensed channels in an unlicensed spectrum with at least one other TRP. Figure 13 This is a flowchart 1300 illustrating the steps in the example method. Step 1310 includes aligning the start time of a potential transmission on at least one of the one or more unlicensed channels with the start time of a potential transmission on at least one other TRP on the at least one of the one or more unlicensed channels. Step 1320 includes performing channel access on the at least one of the one or more unlicensed channels by performing a spatial domain channel access procedure, and / or a combination of a spatial domain channel access procedure and a frequency domain multichannel access procedure. Step 1330 includes transmitting on the at least one of the one or more unlicensed channels at the aligned start time during a joint access period when the at least one of the one or more unlicensed channels is available.

[0234] In some embodiments, the method further includes receiving configuration from a central controller, the configuration including indications of the type of spatial domain channel access procedure and the type of frequency domain multichannel access procedure for jointly accessing the one or more unauthorized channels.

[0235] In some embodiments, performing channel access includes performing the first type of CCA on at least one of the one or more unlicensed channels by configuring a random backoff counter for at least one unlicensed channel for the TRP to perform a first type of free channel assessment (CCA).

[0236] In some embodiments, configuring a random backoff counter for at least one unlicensed channel of a first type CCA for the TRP includes configuring a random backoff counter for one of the unlicensed channels that is different from the at least one other TRP.

[0237] In some embodiments, configuring a random backoff counter for at least one unlicensed channel of a first type CCA for the TRP includes configuring a random backoff counter for the TRP that is the same as that for the at least one other TRP for one of the unlicensed channels.

[0238] In some embodiments, the random backoff counter is generated based at least in part on a single distribution for a contention window, according to a channel access priority level.

[0239] In some embodiments, the random backoff counter is generated based on the distribution of the contention window, the contention window corresponding to the maximum channel access priority level value of all unlicensed channels in the set of the TRP and the at least one other TRP.

[0240] In some embodiments, configuring a random backoff counter for at least one unlicensed channel of the first type CCA for the TRP includes configuring the TRP with the same random backoff counter for all the unlicensed channels as the at least one other TRP.

[0241] In some embodiments, configuring a random backoff counter for at least one unlicensed channel of the first type CCA for the TRP includes configuring the TRP with the same random backoff counter for all the unlicensed channels as the at least one other TRP.

[0242] In some embodiments, performing the first type of CCA on at least one of the one or more unlicensed channels includes performing wideband (WB) CCA on all of the unlicensed channels simultaneously.

[0243] In some embodiments, the method further includes, when the TRP determines that the WB channel is busy during the CCA time slot of the WB CCA, switching from performing the WB CCA to performing the subband CCA for the remaining CCA time slots without terminating the channel access procedure for each individual unlicensed channel.

[0244] In some embodiments, determining that the WB channel is busy during the CCA time slot of the WB CCA includes receiving a notification of CCA failure.

[0245] In some embodiments, the method further includes the TRP performing a second type of CCA on at least one of the one or more unlicensed channels prior to the start time of the potential transmission on the one or more unlicensed channels.

[0246] In some embodiments, the method further includes: when the first type CCA or the second type CCA senses that the unlicensed channel is busy during the CCA time slot, the TRP sends a notification to the at least one other TRP of at least one of the CCA failure and the missed start time of the potential transmission.

[0247] In some embodiments, the method further includes: receiving a notification of a potential transmission start time that is earlier than the start time of a previously scheduled potential transmission, and accordingly re-aligning the start times of the potential transmission.

[0248] In some embodiments, the duration between the end of the first type CCA and the start time of the potential transmission is defined by at least one of the self-delay period, the backoff CCA, and the duration of the second type CCA.

[0249] In some embodiments of this application, a method is provided for a Transmitting and Receiving Point (TRP) to jointly access one or more unlicensed channels in an unlicensed spectrum with at least one other TRP. Figure 14 This is a flowchart 1400 illustrating the steps in the example method. Step 1410 includes receiving an indication of a channel access priority level determined at least according to the respective channel access priority levels of the TRP and the at least one other TRP. Step 1420 involves aligning the start time of a potential transmission on at least one of the one or more unlicensed channels with the start time of a potential transmission on the at least one other TRP on the at least one of the one or more unlicensed channels. Step 1430 includes performing channel access on at least one of the one or more unlicensed channels by performing a spatial domain channel access procedure partially based on the channel access priority level, and / or a combination of performing a spatial domain channel access procedure and the frequency domain multichannel access procedure. Step 1440 includes sending an indication of a successful first type of free channel assessment (CCA) to the at least one other TRP on the at least one of the one or more unlicensed channels. Step 1450 includes transmitting on the at least one of the one or more unlicensed channels at the aligned start time during a joint access period when the at least one of the one or more unlicensed channels is available.

[0250] In some embodiments, the method further includes receiving from a central controller a configuration indicating the type of the spatial domain channel access procedure for jointly accessing the one or more unauthorized channels, or the type of a combination of the spatial domain channel access procedure and the frequency domain multi-channel access procedure.

[0251] In some embodiments, the TRP is selected as the primary TRP based on the controller's selection, or the TRP competes to become the primary TRP by being the first TRP to complete the first type of CCA, and the TRP is assigned as the primary TRP.

[0252] In some embodiments, performing channel access includes performing the first type of CCA on at least one of the one or more unlicensed channels by configuring a random backoff counter for at least one unlicensed channel for the primary TRP.

[0253] In some embodiments, configuring a random backoff counter for at least one unlicensed channel of a first type CCA for the primary TRP includes configuring a random backoff counter for one of the unlicensed channels that is different from that of the secondary TRP.

[0254] In some embodiments, configuring a random backoff counter for at least one unlicensed channel of the first type CCA for the primary TRP includes configuring a random backoff counter for one of the unlicensed channels that is the same as that for the secondary TRP.

[0255] In some embodiments, the random backoff counter is generated based at least in part on a single distribution for a contention window, according to a channel access priority level.

[0256] In some embodiments, the random backoff counter is generated based on the distribution of the contention window, the contention window corresponding to the maximum channel access priority level value of all unlicensed channels in the set of the TRP and the at least one other TRP.

[0257] In some embodiments, performing the first type of CCA on at least one of the one or more unlicensed channels includes simultaneously performing wideband (WB) CCA on a subset of the unlicensed channels.

[0258] In some embodiments, the method further includes, upon receiving a notification of CCA failure, switching from performing the WB CCA to performing the subband CCA for the remaining CCA slots without terminating the channel access procedure for each individual unlicensed channel.

[0259] In some embodiments, the method further includes configuring a random backoff counter for at least one unlicensed channel of a first type CCA for the TRP, which includes assigning at least one unlicensed channel to the TRP such that the TRP is the master TRP for the at least one unlicensed channel, and configuring a random backoff counter for at least one unlicensed channel of the master TRP for the master TRP.

[0260] In some embodiments, the method further includes the main TRP performing a second type of CCA on at least one of the one or more unlicensed channels prior to the start time of the potential transmission on the one or more unlicensed channels.

[0261] In some embodiments, the method further includes sending a notification of CCA failure to at least one other TRP when the primary TRP senses an unlicensed channel busy during a CCA time slot for either a first type CCA or a second type CCA.

[0262] In some embodiments, the method further includes the primary TRP performing the channel access procedure, even if the primary TRP does not transmit any content during the current joint access period, upon receiving a channel access request from the secondary TRP, and even though one or more unauthorized channels are available, the primary TRP does not transmit during the joint access period.

[0263] In some embodiments, the method further includes the primary TRP providing one or more blanking periods after the start time of the potential transmission, during which a second type of CCA may be performed.

[0264] In some embodiments, the primary TRP provides one or more blanking periods that occur due to the switching period between downlink (DL) and uplink (UL) transmissions, or when a notification of CCA failure is received from the at least one other TRP.

[0265] In some embodiments, the method further includes a duration between the end of the first type CCA and the start time of the potential transmission defined by at least one of a self-delay period, a backoff CCA, and a second type CCA duration.

[0266] In some embodiments of this application, a method is provided for a secondary transmit receiving point (TRP) and a primary TRP to jointly access one or more unlicensed channels in an unlicensed spectrum. Figure 15 This is a flowchart 1500 illustrating the steps in the example method. Step 1510 includes receiving an indication of the channel access priority level used by the primary TRP. Step 1520 includes receiving an indication of a successful Type I Free Channel Assessment (CCA) from the primary TRP or at least one of the target start times for potential transmission on at least one of the one or more unlicensed channels. Step 1530 includes performing channel access on at least one of the one or more unlicensed channels by performing a spatial domain channel access procedure, or a combination of a spatial domain channel access procedure and a frequency domain multichannel access procedure. Step 1540 includes transmitting on at least one of the one or more unlicensed channels at the aligned start time during a joint access period when at least one of the one or more unlicensed channels is available.

[0267] In some embodiments, the method further includes aligning the start time of a potential transmission on at least one of the one or more unlicensed channels with the start time of a potential transmission of the primary TRP on at least one of the one or more unlicensed channels.

[0268] In some embodiments, the method further includes sending a channel access request to the primary TRP when the secondary TRP intends to transmit during the current joint access period, regardless of whether the primary TRP intends to transmit during the current joint access period.

[0269] In some embodiments, the method further includes the secondary TRP performing a second type of CCA on at least one of the one or more unlicensed channels prior to the start time of the target transmission jointly transmitted on the one or more unlicensed channels.

[0270] In some embodiments, the method further includes, when the second type of CCA senses that the unlicensed channel is busy, causing the secondary TRP to determine that the unlicensed channel is unavailable for the secondary TRP, the secondary TRP sends a CCA failure notification to the at least one TRP.

[0271] In some embodiments, the method further includes the TRP providing one or more blanking periods after the start time of the potential transmission, during which a second type of CCA may be performed.

[0272] In some embodiments, the TRP provides one or more blanking periods due to a switching period between downlink (DL) and uplink (UL) transmissions, or when a notification of CCA failure is received from the at least one TRP.

[0273] In some embodiments, the method further includes performing a second type of CCA on at least one of the one or more unlicensed channels, which includes performing a wideband (WB) CCA on a subset of adjacent channels of the one or more unlicensed channels simultaneously.

[0274] Although this disclosure describes methods and processes having steps in a particular order, one or more steps of the methods and processes may be appropriately omitted or changed. One or more steps may occur in a different order than described.

[0275] Although this disclosure has been described at least in part with respect to methods, those skilled in the art will understand that this disclosure also relates to various components for performing at least some aspects and features of the described methods, whether by hardware components, software, or any combination of both. Therefore, the technical solutions of this disclosure can be embodied in the form of a software product. Suitable software products may be stored in pre-recorded storage devices or other similar non-volatile or non-transitory computer-readable media, such as DVDs, CD-ROMs, USB flash drives, removable hard drives, or other storage media. Software products include examples of instructions tangibly stored thereon that enable processing devices (e.g., personal computers, servers, or network devices) to perform the methods disclosed herein.

[0276] This disclosure may be embodied in other specific forms without departing from the subject matter of the claims. The exemplary embodiments described are to be considered in all respects as illustrative rather than restrictive. Selected features from one or more of the foregoing embodiments may be combined to create alternative embodiments not explicitly described, and features suitable for such combinations are understood within the scope of this disclosure.

[0277] All values ​​and sub-ranges within the scope of the disclosure are also disclosed. Furthermore, although the systems, devices, and processes disclosed and illustrated herein may include a specific number of elements / components, these systems, devices, and components may be modified to include more or fewer such elements / components. For example, although any element / component disclosed may be considered singular, the embodiments disclosed herein may be modified to include multiple such elements / components. The subject matter described herein is intended to cover and include all appropriate technical variations.

Claims

1. A method for a Transmitter / Receiver Point (TRP) to jointly access one or more unlicensed channels in an unlicensed spectrum with at least one other TRP, the method comprising: The TRP and the at least one other TRP perform channel access on the one or more unlicensed channels by performing a spatial domain channel access procedure, and / or a combination of a spatial domain channel access procedure and a frequency domain multichannel access procedure, in order to facilitate the execution of potential transmissions by the TRP and the at least one other TRP. as well as When at least one of the one or more unlicensed channels is available, the potential transmission of the TRP and the at least one other TRP shall be performed on the at least one of the one or more unlicensed channels at the start time of the alignment. The start time of the alignment is at least based on the contention window of the idle channel evaluation CCA of the at least one other TRP, which is randomly generated.

2. The method according to claim 1, characterized in that, The TRP and the at least one other TRP are different antenna sets of the same base station.

3. The method according to claim 1 or 2, characterized in that, The TRP and the at least one other TRP are a set of antennas with different quasi-co-location QCL assumptions.

4. The method of claim 1 or 2, further comprising receiving configuration, the configuration including indications of the type of spatial domain channel access procedure and the type of frequency domain multichannel access procedure for the TRP and the at least one other TRP to access the one or more unlicensed channels.

5. The method according to claim 1 or 2, wherein, Performing channel access includes: performing the first type of CCA on the one or more unlicensed channels by configuring a random backoff counter for one or more unlicensed channels for the TRP to perform a first type of idle channel assessment CCA.

6. The method according to claim 5, wherein, Configuring a random backoff counter for one or more unlicensed channels for the TRP for a first type of CCA includes: configuring a random backoff counter for the TRP that is different from the at least one other TRP for one of the one or more unlicensed channels.

7. The method according to claim 5, wherein, The random backoff counter is generated based on the distribution of the contention window, which corresponds to the maximum channel access priority level value of all unlicensed channels in the set of the TRP and at least one other TRP.

8. The method according to claim 5, wherein, Configuring a random backoff counter for one or more unlicensed channels for the TRP for the first type of CCA includes: configuring the TRP with a random backoff counter that is the same as that for the at least one other TRP for all the unlicensed channels.

9. The method according to claim 8, wherein, Performing the first type of CCA on at least one of the one or more unlicensed channels includes simultaneously performing wideband WB CCA on all of the unlicensed channels.

10. The method of claim 9, further comprising, when the TRP determines that the WB channel is busy during the CCA slot of the WB CCA, switching from performing the WB CCA to performing a subband CCA for the remaining CCA slots without terminating the channel access procedure for each individual unlicensed channel.

11. The method according to claim 10, wherein, Determining that the WB channel is busy during the CCA time slot of the WB CCA includes receiving a notification of CCA failure.

12. The method of claim 5, further comprising the TRP performing a second type CCA on at least one of the one or more unlicensed channels prior to the start time of the alignment.

13. The method of claim 12, further comprising: When the first type CCA or the second type CCA senses that the unlicensed channel is busy during the CCA time slot, the TRP sends a notification to at least one other TRP of at least one of the CCA failure and the missed start time of the potential transmission.

14. The method according to claim 1 or 2, further comprising: Receive notification of a potential transmission start time that is earlier than the previously scheduled potential transmission start time, and realign the start time of the potential transmission accordingly.

15. The method according to claim 5, wherein, The duration between the end of the first type of CCA and the start time of the alignment is defined by at least one of the self-delay period, the backoff CCA, and the duration of the second type of CCA of the TRP.

16. A communication apparatus comprising a transmitting / receiving point (TRP) and at least one other TRP; The TRP and the at least one other TRP are configured as follows: Channel access is performed on one or more unlicensed channels by executing a spatial domain channel access procedure, and / or a combination of a spatial domain channel access procedure and a frequency domain multichannel access procedure, to facilitate the execution of potential transmissions of the TRP and the at least one other TRP; and When at least one of the one or more unlicensed channels is available, the potential transmission of the TRP and the at least one other TRP shall be performed on the at least one of the one or more unlicensed channels at the start time of the alignment. in, The start time of the alignment is at least based on the contention window of the idle channel evaluation CCA of the at least one other TRP, which is randomly generated.

17. The communication device according to claim 16, characterized in that, The TRP and the at least one other TRP are different antenna sets of the same base station.

18. The communication device according to claim 16 or 17, characterized in that, The TRP and the at least one other TRP are a set of antennas with different quasi-co-location QCL assumptions.

19. The communication device according to claim 16 or 17, wherein, The TRP and the at least one other TRP are also configured to receive a configuration that includes an indication of the type of spatial domain channel access procedure and the type of frequency domain multichannel access procedure for the TRP and the at least one other TRP to access the one or more unlicensed channels.

20. The communication device according to claim 16 or 17, wherein, Specifically, the first type of CCA is performed on the one or more unlicensed channels by configuring a random backoff counter for one or more unlicensed channels for the TRP to perform the first type of idle channel assessment CCA.

21. The communication device according to claim 20, wherein, Specifically, the TRP is configured with a random backoff counter for one of the one or more unlicensed channels, which is different from the at least one other TRP.

22. The communication device according to claim 20, wherein, Specifically, the random backoff counter is configured to be generated based on the distribution of the contention window, the contention window corresponding to the maximum channel access priority level value of all unlicensed channels in the set of the TRP and at least one other TRP.

23. The communication device according to claim 20, wherein, Specifically, the TRP is configured with the same random backoff counter used for all the unlicensed channels as the at least one other TRP.

24. The communication device according to claim 21, wherein, It is also configured to perform wideband WB CCA on all of the aforementioned unlicensed channels.

25. The communication device according to claim 24, wherein, It is also configured to, when the TRP determines that the WB channel is busy during the CCA time slot of the WB CCA, switch from performing the WB CCA to performing the subband CCA for the remaining CCA time slots without terminating the channel access procedure for each individual unlicensed channel.

26. The communication device according to claim 25, wherein, It is also configured to receive notifications of CCA failures.

27. The communication device according to claim 20, wherein, It is also configured to perform a second type of CCA on at least one of the one or more unlicensed channels before the start time of the alignment.

28. The communication device according to claim 27, wherein, It is also configured to send a notification of at least one of the following to the at least one other TRP when the first type CCA or the second type CCA senses that the unlicensed channel is busy during the CCA time slot: a notification of CCA failure and a missed start time of a potential transmission.

29. The communication apparatus of claim 16 or 17 is further configured to receive a notification of the start time of a potential transmission that is earlier than the start time of a previously scheduled potential transmission, and accordingly re-align the start time of the potential transmission.

30. The communication device according to claim 20, wherein, The duration between the end of the first type of CCA and the start time of the alignment is defined by at least one of the self-delay period, the backoff CCA, and the duration of the second type of CCA of the TRP.

31. A communication device, characterized in that, include: At least one processor; as well as A memory that is communicatively connected to the at least one processor; in The memory stores computer instructions executable by the at least one processor, which, when executed by the at least one processor, enables the at least one processor to perform the method of any one of claims 1-15.

32. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when run on a computer, causes the computer to perform the method as described in any one of claims 1-15.

33. A computer program product, characterized in that, The computer program product includes a computer program that, when run on a computer, causes the computer to perform the method as described in any one of claims 1-15.

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