Channel access method and device

Abstract

A method for channel access is provided. The method comprises the steps of: determining a start time and a period of a first fixed frame period (FFP) of a cell on an operation channel of an unlicensed frequency band; a start time and a period of a second fixed frame period for uplink transmission of the cell are determined. According to the device and the method for channel access provided by the invention, the delay of uplink transmission increased by limitation in the prior art and the reduction of the overall infinite resource utilization rate can be avoided.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application is a divisional application of the Chinese patent application with application number CN202080037341.X (PCT / CN2020 / 119630) filed on September 30, 2020, and all the contents of which are incorporated into this application by reference. Technical Field

[0003] The present application relates generally to mobile communications, and more particularly to methods and apparatus for channel access. Background Art

[0004] In a typical mobile communication environment, a user equipment (UE) (also called a mobile station (MS)), such as a mobile phone (also called a cellular or cell phone), or a tablet personal computer (PC) has wireless communication capabilities and can transmit voice and / or data signals to one or more mobile communication networks. Wireless communication between UE and mobile communication network can be performed using various radio access technologies (Radio Access Technology, RAT), such as Global System for Mobile communications (GSM) technology, General Packet Radio Service (GPRS) technology, Enhanced Data rates for Global Evolution (EDGE) technology, Wideband Code Division Multiple Access (WCDMA) technology, Code Division Multiple Access 2000 (CDMA-2000) technology, Time Division-Synchronous Code Division Multiple Access (TD-SCDMA) technology, Worldwide Interoperability for Microwave Access (WiMAX) technology, Long Term Evolution (LTE) technology, Advanced LTE (LTE-Advanced, LTE-A) technology, etc.

[0005] These wireless technologies have been used in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate at municipal, national, regional and even global levels. An example of an emerging telecommunication standard is 5G New Radio (NR). 5G NR is a set of enhancements to the LTE mobile standard promulgated by the Third Generation Partnership Project (3GPP). It is designed to better support mobile broadband Internet access by increasing spectrum efficiency, reducing costs and improving services.

[0006] On the other hand, with the rapid development of the "Internet of Things" (IoT), the demand for supporting machine communications is growing exponentially. In order to meet this exponentially growing demand for mobile communications, additional spectrum (i.e., radio spectrum) is required. Due to the limited amount of licensed spectrum, mobile service providers seek to combine unlicensed spectrum with their own licensed spectrum to create larger bandwidth for users. In order to promote efficient and fair sharing of unlicensed spectrum, it may be necessary to support the commonly adopted energy detection-based channel access mechanism, called Listen-Before-Talk (LBT), based on the regulations of each country. Depending on the regional regulations and use cases, the LBT process can be classified as performing channel sensing for a deterministic duration or a random duration, or not performing any channel sensing (i.e., no LBT). In addition, there are two operation modes, including Frame-Based Equipment (FBE) operation and Load-Based Equipment (LBE) operation.

[0007] In FBE operation, a device (e.g., a gNB or UE) may be configured with a frame period, where the start of each frame corresponds to a possible start time of transmission by the device. If the device operates as an initiating device, an LBT procedure should be performed before the start of a frame period to ensure that the operating channel is idle. Each frame includes a Channel Occupancy Time (COT) period, during which downlink and / or uplink transmissions may occur, and an idle period, during which the initiating device should avoid any transmission and reception operations. In the traditional practice of FBE operation (e.g., 3GPP Release-16 NR-U FBE operation), only gNB-initiated COT supports uplink transmission. That is, the gNB always needs to perform an LBT procedure and transmit some downlink signals before any UE can make an uplink transmission. This limitation will inevitably increase the latency of uplink transmissions, especially those initiated by UEs and sent on configured uplink resources, and adversely reduce the overall radio resource utilization. Summary of the invention

[0008] In order to solve the above problems, the present application proposes to support UE-initiated COT for FBE operation by allowing the UE to operate as an initiating device with a deterministic fixed frame period (FFP) to perform uplink transmission in a manner that complies with regional regulations (e.g., European Telecommunications Standards Institute (ETSI) rules).

[0009] In a first aspect of the present application, a channel access method is provided. The method comprises the following steps: determining a start time and a period of a first FFP of a first cell on an operating channel of an unlicensed frequency band. Determining a start time and a period of a second FFP of an uplink transmission of the first cell.

[0010] In a first implementation of the first aspect, the method further comprises the following steps: determining a COT period or an idle period of the first FFP, and determining a COT period or an idle period of the second FFP.

[0011] In a second implementation of the first aspect, the period of the second FFP is determined according to the first cell configuration or signal notification information, or according to the period of the first FFP, or according to the period of the uplink resource type, or a combination of the above.

[0012] In a third embodiment of the first aspect, the start time of the second FFP is determined according to information of semi-static configuration or dynamic signal notification of the first cell, or according to the configuration received from the second cell, or according to the start time of the first FFP, or according to the start time of a type of uplink resource, or a combination of the above.

[0013] In a fourth implementation of the first aspect, the start time of the second FFP indicates an offset, a system frame boundary, or a system subframe boundary relative to the start time of the first FFP.

[0014] In a sixth embodiment of the first aspect, the COT period or idle period of the second FFP is determined according to information of semi-static configuration or dynamic signal notification of the first cell, or according to the COT period or idle period of the first FFP, or according to predefined rules, or a combination of the above.

[0015] In a seventh embodiment of the first aspect, this type of uplink resources includes a physical random access channel (PRACH) resource for random access, a physical uplink shared channel (PUSCH) resource for configuring authorization, or a physical uplink control channel (PUCCH) resource for scheduling requests, channel state information (CSI) reports, or hybrid automatic repeat request (HARQ) feedback.

[0016] In an eighth embodiment of the first aspect, the method also includes the following steps: determining whether a downlink transmission from the first cell occurs within a duration after the start time of the first FFP to which the second uplink resource is allocated; in response to a downlink transmission from the first cell occurring within a duration after the start time of the first FFP, performing another uplink transmission to the first cell using the second uplink resource in the first FFP; wherein the UE acts as an initiating device when initiating an uplink transmission according to the second FFP, and acts as a responding device when initiating another uplink transmission according to the first FFP.

[0017] In a second aspect of the present application, a device for channel access is provided. The device includes a wireless transceiver and a controller. The wireless transceiver is configured to perform wireless transmission and reception to and from a first cell of a mobile communication network. The controller is coupled to the wireless transceiver, and is used to determine the start time and period of a first fixed frame period of the first cell on an operating channel of an unlicensed frequency band, wherein the first fixed frame period is used to indicate the channel occupancy time initiated by the network node; and to determine the start time and period of a second fixed frame period of an uplink transmission initiated to the first cell, wherein the second fixed frame period is used to obtain the channel occupancy time initiated by a user equipment for the uplink transmission.

[0018] In a first implementation of the second aspect, the controller is further configured to determine a COT period or an idle period of the first FFP, and to determine a COT period or an idle period of the second FFP.

[0019] In a second implementation of the second aspect, the period of the second FFP is determined according to information configured or signaled by the first cell, or according to the period of the first FFP, or according to the period of a type of uplink resource, or a combination of the above.

[0020] In a third embodiment of the second aspect, the start time of the second FFP is determined according to information of semi-static configuration or dynamic signal notification of the first cell, or according to the start time of the first FFP, or according to the start time of a type of uplink resource, or a combination of the above.

[0021] In a fourth implementation of the second aspect, the start time of the second FFP indicates an offset, a system frame boundary, or a system subframe boundary relative to the start time of the first FFP.

[0022] In a fifth embodiment of the second aspect, the COT period or idle period of the second FFP is determined according to information of semi-static configuration or dynamic signal notification of the first cell, or according to the COT period or idle period of the first FFP, or according to predefined rules, or a combination of the above.

[0023] In a sixth implementation of the second aspect, this type of uplink resources includes PRACH resources for random access, PUSCH resources for configuring authorization, or PUCCH resources for scheduling requests, CSI reports, and HARQ feedback.

[0024] In a third aspect of the present application, a channel access method is provided. The method comprises the following steps: determining an FFP of a cell on an operating channel of an unlicensed frequency band; determining whether a downlink transmission from the cell occurs within a first duration after the FFP start time to which uplink resources are allocated; in response to a downlink transmission from the cell occurring within the first duration after the FFP start time, performing an uplink transmission to the cell using uplink resources in the FFP.

[0025] In a first embodiment of the third aspect, the method further comprises the following steps: performing an LBT process on the operating channel within a second time duration before the start of the uplink transmission, wherein the uplink transmission is performed in response to the LBT process indicating that the operating channel is idle.

[0026] In a second implementation of the third aspect, the listen-before-speak process may be configured as a one-time listen-before-speak process or as a non-listen-before-speak process.

[0027] In a third implementation of the third aspect, the FFP is determined according to Remaining Minimum System Information (RMSI) or dedicated Radio Resource Control (RRC) signaling from the cell.

[0028] According to the apparatus and method for channel access provided by the present invention, the delay of uplink transmission increased by the limitations in the prior art and the reduction of the overall unlimited resource utilization rate can be avoided.

[0029] Other aspects and features of the present application will become apparent to those skilled in the art after reading the following description of specific embodiments of the apparatus and method for channel access. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The present application can be more fully understood by reading the following detailed description and embodiments in conjunction with the accompanying drawings, in which:

[0031] Figure 1 is a block diagram of an exemplary Licensed Assisted Access (LAA) mobile communication system according to an embodiment of the present application;

[0032] Figure 2 is a block diagram showing a UE 101 according to an embodiment of the present application;

[0033] Figure 3 A flowchart of a method for uplink transmission in FBE operation according to an embodiment of the present application;

[0034] Figure 4It is a schematic diagram of supporting UE-initiated COT for FBE operation in the first embodiment of the present application;

[0035] Figure 5 This is a schematic diagram of supporting UE-initiated COT for FBE operation according to the second embodiment of the present application;

[0036] Figure 6 This is a schematic diagram of supporting UE-initiated COT for FBE operation in the third embodiment of the present application;

[0037] Figure 7 A flow chart of a method for uplink transmission in FBE operation according to another embodiment of the present application;

[0038] Figure 8 A schematic diagram of a UE-initiated COT supporting FBE operation according to a fourth embodiment of the present application;

[0039] Fig. 9 A schematic diagram of a UE-initiated COT supporting FBE operation according to a fifth embodiment of the present application;

[0040] Fig.10 A schematic diagram of a UE-initiated COT supporting FBE operation according to a sixth embodiment of the present application; and

[0041] Fig.11 This is a schematic diagram of supporting UE-initiated COT for FBE operation according to the seventh embodiment of the present application. DETAILED DESCRIPTION

[0042] The following description is to illustrate the general principles of the present application and should not be considered as limiting. It should be understood that these embodiments can be implemented by software, hardware, firmware or any combination thereof. The terms "comprise", "comprising", "includes" and / or "including", when used in this application, specify the presence of the features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or their groups.

[0043] Figure 1 is a block diagram of an exemplary LAA mobile communication system according to an embodiment of the present application.

[0044] like Figure 1As shown, the mobile communication system 100 may include one or more mobile communication networks, each of which has infrastructure units, such as 102 and 104. Each infrastructure unit may also be referred to as an access point, an access terminal, a base station, or other terms used in the art. Each of the base stations 102 and 104 serves a geographic area. In this example, the geographic areas served by the base stations 102 and 104 overlap. In another embodiment, the base stations 102 and 104 may be geographically located at the same location.

[0045] In one embodiment, if the mobile communication network is a 5G NR network, each of base stations 102 and 104 may be a next generation NodeB (gNB) that supports licensed bands and / or unlicensed bands, and each gNB may also include one or more transmission reception points (TRPs), wherein each gNB or TRP may be referred to as a 5G cell site.

[0046] Specifically, base station 102 provides wireless communication services to UE 101 in primary cell 103 through a licensed frequency band, while base station 104 communicates with UE 101 in secondary cell 105 through an unlicensed frequency band. Secondary cell 105 may also be referred to as a "small cell". In one example, base station 102 and base station 104 communicate with UE 101 via 5G NR wireless communication.

[0047] UE 101 may be a feature phone, a smart phone, a tablet personal computer (PC), a laptop computer, or any wireless communication device that supports the RAT (e.g., 5G NR technology) used by the mobile communication network to which base stations 102 and 104 belong.

[0048] The exponential growth of data consumption has created a large bandwidth demand that cannot be met by traditional wireless systems. In order to meet the growing demand for more bandwidth, new wireless systems with larger available bandwidth are needed. LAA mobile communication systems can be used to provide larger available bandwidth. LAA mobile communication systems use unlicensed bands in addition to using licensed bands at the same time, thereby providing additional available bandwidth for UEs in LAA mobile communication systems. For example, UE 101 can benefit from using licensed bands and unlicensed bands at the same time in mobile communication system 100. LAA mobile communication systems not only provide additional bandwidth for greater overall data communications, but also provide consistent data connections due to the presence of two independent communication links. Having multiple available communication links increases the likelihood that the UE can achieve correct data communication with at least one base station at any given moment. While using unlicensed spectrum to provide more available bandwidth, the use of unlicensed spectrum faces practical problems that need to be solved.

[0049] One particular issue is that uplink transmissions are supported only in gNB-initiated COT. That is, even if the gNB has configured uplink resources, the gNB always needs to perform an LBT procedure and send some downlink signals before any UE can transmit. This limitation will inevitably increase the latency of uplink transmissions and reduce overall radio resource utilization. According to a novel aspect, UE-initiated COT for FBE operation is supported by allowing UE 101 to perform uplink transmissions as an initiating device with deterministic FFP in a manner that complies with regional regulations (e.g., European Telecommunications Standards Institute (ETSI) regulations).

[0050] exist Figure 1 In the example of , for downlink LAA, the base station 104 performs LBT to compete for channel ownership and initiates downlink data transmission. For uplink LAA, both the base station 104 and the UE 101 can perform LBT to compete for channel ownership. For example, the base station 104 can perform LBT for PDCCH transmission or some other downlink signal or / channel transmission to enable uplink resources configured for the UE 101, so that the UE 101 can perform PUSCH transmission using the configured uplink resources after detecting the downlink transmission from the base station and assuming that the base station has acquired the COT. That is, uplink transmission is supported in the COT initiated by the gNB. Alternatively, the UE 101 may actively perform LBT to obtain the COT for uplink transmission. Examples of uplink transmissions include PRACH, PUCCH, PUSCH, or Sounding Reference Signal (SRS) transmissions. In this way, uplink transmissions are supported in the COT initiated by the UE.

[0051] It should be understood that Figure 1The mobile communication system 100 described in the embodiments is for illustration purposes only and is not intended to limit the scope of the present application. For example, the RAT used by the mobile communication system 100 may be a conventional technology of 5G NR (e.g., LTE / LTE-A / TD-LTE), or a future enhancement of 5G NR (e.g., 6G / 7G / 8G).

[0052] Figure 2 is a block diagram showing a UE 101 according to an embodiment of the present application.

[0053] like Figure 2 As shown, UE 101 may include a wireless transceiver 10 , a controller 20 , a storage device 30 , a display device 40 , and an input / output (I / O) device 50 .

[0054] The wireless transceiver 10 is configured to perform wireless transmission and reception to and from the base station 102 and the base station 104 .

[0055] Specifically, the wireless transceiver 10 may include a baseband processing device 11, a radio frequency (RF) device 12, and an antenna 13, wherein the antenna 13 may include an antenna array for beamforming.

[0056] The baseband processing device 11 is used to perform baseband signal processing and control the communication between one or more user identification cards (not shown) and the RF device 12. The baseband processing device 11 may include multiple hardware components to perform baseband signal processing, including analog-to-digital conversion (ADC) / digital-to-analog conversion (DAC), gain adjustment, modulation / demodulation, encoding / decoding, etc.

[0057] The RF device 12 can receive an RF wireless signal via an antenna 13, convert the received RF wireless signal into a baseband signal, and the baseband signal is processed by the baseband processing device 11, or receive a baseband signal from the baseband processing device 11 and convert the received baseband signal into an RF wireless signal, and then the RF wireless signal is transmitted via the antenna 13. The RF device 12 can also include multiple hardware devices to perform radio frequency conversion. For example, the RF device 12 may include a mixer to multiply the baseband signal with a carrier oscillating in the radio frequency of one or more supported RATs, where the radio frequency can be any radio frequency used in 5G NR technology (for example, 30 GHz to 300 GHz for millimeter wave mmWave, or 5 GHz for unlicensed bands), or may be 900 MHz, 2100 MHz or 2.6 GHz used by LTE / LTE-A / TD-LTE technology, or other radio frequencies, depending on the RAT used.

[0058] The controller 20 can be a general-purpose processor, a micro control unit (MCU), an application processor, a digital signal processor (DSP), a graphics processing unit (GPU), a holographic processing unit (HPU), a neural processing unit (NPU), etc. It includes a variety of circuits for providing data processing and computing functions, controlling the wireless transceiver 10 to wirelessly communicate with base stations 102 and 104, storing and retrieving data (e.g., program code) sent to and from the storage device 30, sending a series of frame data (e.g., representing text messages, graphics, images, etc.) to the display device 40, and receiving user input or output signals via the I / O device 50.

[0059] In particular, the controller 20 coordinates the aforementioned operations of the wireless transceiver 10 , the storage device 30 , the display device 40 , and the I / O device 50 to execute the method of the present application.

[0060] In another embodiment, the controller 20 may be incorporated into the baseband processing device 11 to function as a baseband processor.

[0061] As will be appreciated by those skilled in the art, the circuitry of the controller 20 will typically include transistors configured to control the operation of the circuitry in accordance with the functions and operations described herein. As will be further appreciated, the specific structure or interconnection of the transistors is typically determined by a compiler, such as a register transfer language (RTL) compiler. The RTL compiler may be operated by a processor based on a script that is very similar to assembly language code to compile the script into a form for layout or manufacture of the final circuit. In fact, RTL is well known for its role and use in facilitating the design of electronic and digital systems.

[0062] The storage device 30 may be a non-temporary machine-readable storage medium, including a memory such as FLASH memory or non-volatile random access memory (NVRAM), or a magnetic storage device such as a hard core. A disk or tape or optical disk or any combination thereof for storing data (e.g., configuration received in Remaining Minimum System Information (RMSI) or dedicated Radio Resource Control (RRC) signaling information), instructions and / or program codes for applications, communication protocols and / or methods of the present application.

[0063] The display device 40 may be a liquid crystal display (LCD), a light-emitting diode (LED), an organic LED (OLED) display, or an electronic paper display (EPD), etc., for providing a display function. Alternatively, the display device 40 may further include one or more touch sensors disposed on or below the display device 40 for sensing a touch, contact, or proximity of an object such as a finger or a stylus.

[0064] The I / O device 50 may include one or more buttons, keyboards, mice, touch pads, cameras, microphones and / or speakers, etc., as a man-machine interface (MMI) for interacting with a user.

[0065] It should be understood that Figure 2 The components described in the embodiments are for illustrative purposes only and are not intended to limit the scope of the present application.

[0066] For example, the UE may include more components, such as a power source and / or a Global Positioning System (GPS) device, where the power source may be a removable / replaceable battery that provides power to all other components of the UE, and the GPS device may provide location information of the UE for use by some location-based services or applications. Alternatively, the UE may include fewer components. For example, the UE may not include a display device 40 and / or an I / O device 50.

[0067] Figure 3 A flowchart of a method for uplink transmission in FBE operation provided in an embodiment of the present application.

[0068] In this embodiment, the method may be applied to and performed by a UE (eg, UE 101) operating in FBE mode. Specifically, when the UE operates in FBE mode, the transmission / reception structure has a periodic timing with a period equal to FFP.

[0069] First, the UE determines the start time and period of the first FFP of the first cell (e.g., the secondary cell 105) on the operating channel of the unlicensed band (step S310). Specifically, the first FFP is used to share the COT initiated by the gNB.

[0070] The configuration of the first FFP may be signaled to the UE via broadcast information (eg, RMSI) and / or dedicated signaling (eg, Radio Resource Control (RRC) signaling). Note that it is assumed that the start time of the first FFP is at the system frame / subframe boundary.

[0071] Next, the UE determines a start time and period of a second FFP for initiating uplink transmission to the first cell (step S320).

[0072] Specifically, the second FFP is used to obtain a UE-initiated COT for uplink transmission, and the start time of the second FFP indicates an offset relative to the start time of the first FFP, a system frame boundary, or a system frame boundary or subframe boundary.

[0073] In one embodiment, the UE may also receive a configuration from a second cell on an operating channel in a licensed frequency band or an unlicensed frequency band, where the second cell may be the same as or different from the first cell.

[0074] For further explanation, the period of the second FFP can be determined according to the information configured or signaled by the first cell, or according to the configuration received from the second cell, or according to the period of the first FFP, or according to the period of a type of uplink resource, or a combination of the above. The start time of the second FFP can be determined according to the information semi-statically configured or dynamically signaled by the first cell, or according to the configuration received from the second cell, or according to the start time of the first FFP, or according to the start time of a type of uplink resource, or a combination of the above. The COT period or idle period of the second FFP can be determined according to the information semi-statically configured or dynamically signaled by the first cell, or according to the configuration received from the second cell, or according to the COT period or idle period of the first FFP, or according to a predefined rule, or a combination of the above. For example, the idle period of the second FFP can be determined as a ratio of the period of the second FFP, which ratio can be pre-defined in the 3GPP specification or configured by the cell. Alternatively, the idle period of the second FFP can be set to a value not less than a predetermined value.

[0075] For example, the information configured or signaled from the first cell may be broadcast information or dedicated signaling information.

[0076] For example, this type of uplink resource may refer to PRACH resources for random access, PUSCH resources for configuration grant, or PUCCH resources for scheduling request, CSI report and HARQ feedback, which are configured based on the broadcast information (e.g., RMSI) of the first cell.

[0077] Then, the UE performs an LBT procedure on an operating channel of the unlicensed band (step S330).

[0078] Specifically, the LBT process is performed during the duration immediately before the second FFP start time.

[0079] Thereafter, the UE performs uplink transmission to the first cell using the first uplink resource in the second FFP in response to the LBT process indicating that the operating channel of the unlicensed band is idle (step S340), and the method ends.

[0080] Specifically, the uplink transmission may be PRACH transmission, PUSCH transmission, PUCCH transmission or SRS transmission.

[0081] It should be noted that the UE operates as an initiating device when initiating uplink transmission according to the second FFP.

[0082] Figure 4 This is a schematic diagram of a UE-initiated COT supporting FBE operation according to the first embodiment of the present application.

[0083] like Figure 4 As shown, the UE determines the first FFP ( Figure 4 In addition to the first FFP, the UE also determines the second FFP ( FFP1 ) according to the period of one type of uplink resource (e.g., PRACH resource, PUSCH resource, or PUCCH resource). Figure 4 In the example, the UE is referred to as FFP2 because the UE also operates as an initiator of the FBE operation. Specifically, the start time and period of the second FFP are determined to be equal to the start time and period of one type of uplink resource.

[0084] When the UE wants to send an uplink signal / data, it does so during the duration immediately before the uplink resource starts (in Figure 4Specifically, the LBT process may include one or more Clear Channel Access (CCA) evaluations for checking whether the operating channel is idle.

[0085] If the LBT process indicates that the operating channel is idle, it means that the UE acquires the COT by itself (i.e., UE-initiated COT), and the UE can continue to perform uplink transmission in the UE-initiated COT instead of sharing the gNB-initiated COT.

[0086] Figure 5 This is a schematic diagram of a UE-initiated COT supporting FBE operation according to the second embodiment of the present application.

[0087] like Figure 5 As shown, the second FFP can be determined ( Figure 5 denoted as FFP2 in the figure) is the same as the first FFP, or is different from the first FFP.

[0088] When the UE wants to transmit uplink signals / data, it transmits the first duration (in Figure 5 The first LBT process (denoted as LBT1) is performed within 10 seconds (denoted as T1 in the figure). If the first LBT process indicates that the operating channel is idle, it means that the UE obtains the COT by itself (i.e., the UE-initiated COT). If the UE does not want to perform uplink transmission immediately after obtaining the UE-initiated COT, or the configured uplink resources are scheduled at a time after the start of FFP, the UE needs to perform the uplink transmission with a second duration (in the frame) before the uplink resources in the frame. Figure 5 The UE performs a second LBT process (denoted as LBT2) at the uplink resource. If the second LBT process indicates that the operating channel is idle, the UE may perform uplink transmission on the uplink resource.

[0089] Otherwise, if the first LBT process of the next frame fails (ie, the operating channel is occupied), the UE is not allowed to use the uplink resources in the frame for uplink transmission, and therefore, the second LBT process in the frame can be skipped.

[0090] The first duration (T1) and the second duration (T2) may be configured to be the same or different.

[0091] Figure 6 This is a schematic diagram of supporting UE-initiated COT for FBE operation according to the third embodiment of the present application.

[0092] like Figure 6 As shown, the second FFP (in Figure 5 denoted as FFP2 in FIG. 1 ) is determined to be the same as the first FFP or different from the first FFP.

[0093] When a UE wants to transmit uplink signals / data, it is on for the duration before FFP starts (in Figure 6 If the LBT process indicates that the operating channel is idle, it means that the UE acquires the COT by itself (i.e., the UE-initiated COT), and the UE continues to perform uplink transmission on the uplink resources in the frame without performing another LBT process before the uplink transmission.

[0094] Otherwise, if the LBT process of the next frame fails (ie, the operating channel is occupied), the UE is not allowed to use the uplink resources in the frame for uplink transmission.

[0095] Figure 7 The present invention is a flowchart of a method for uplink transmission in FBE operation according to another embodiment of the present invention.

[0096] In this embodiment, the method may be applied to and executed by a UE (eg, UE 101) operating in FBE mode.

[0097] First, the UE determines the FFP of a cell (eg, the secondary cell 105 ) on an operating channel of an unlicensed band (step S710 ).

[0098] Specifically, FFP is determined based on RMSI or dedicated RRC signaling from the cell.

[0099] Next, the UE determines whether downlink transmission from the cell occurs within a first duration after the start time of the FFP to which the uplink resources are allocated (step S720).

[0100] Specifically, the downlink transmission includes at least one of the following: DMRS, SSB, CSI-RS, TRS, PDCCH signal, PDSCH signal, GC-PDCCH signal, PDCCH DMRS and PDSCH DMRS.

[0101] Thereafter, the UE performs uplink transmission to the cell using uplink resources in the FFP in response to downlink transmission from the cell occurring within a first duration after the start time of the FFP (step S730), and the method ends.

[0102] Figure 8 This is a schematic diagram of supporting UE-initiated COT for FBE operation according to the fourth embodiment of the present application.

[0103] like Figure 8 As shown, the UE determines the first FFP ( Figure 8It is represented as FFP1 in the figure because the UE acts as the responding device of the FBE operation.

[0104] At the beginning of each FFP, the UE assumes that the gNB has successfully performed the first LBT procedure (at Figure 8 1), so the UE monitors whether there is a downlink transmission from the cell. That is, the UE is required to at least detect / decode the downlink transmission that may occur in the frame. If there is a downlink transmission in the frame, the UE immediately before the uplink resource starts (in Figure 8 The second LBT process is performed within 10 seconds (indicated as T in Figure 8 If the second LBT process indicates that the operating channel is idle, it means that the UE is allowed to share the COT initiated by the gNB and use the uplink resources to perform uplink transmission.

[0105] Based on the indication of the scheduling PDCCH, the second LBT process may be configured as a one-shot LBT or no LBT (ie, the second LBT process may be skipped). The first duration (T1) and the second duration (T2) may be configured to be the same or different.

[0106] Fig. 9 It is a schematic diagram of supporting UE-initiated COT for FBE operation according to the fifth embodiment of the present application.

[0107] like Fig. 9 As shown, the UE determines the first FFP ( Fig. 9 In addition to the first FFP, the UE also determines a second FFP (in Fig. 9 In the example, it is represented as FFP2) because the UE also operates as the initiator of the FBE operation.

[0108] Specifically, the second FFP starts from the duration after the start of the first FFP and ends before the uplink resources in the first FFP start. The start time, period, COT period and / or idle period of the second FFP can be explicitly configured by the cell or notified by signal.

[0109] When the UE wants to initiate a first uplink transmission, it performs a first LBT procedure (at Fig. 9 If the first LBT process indicates that the operating channel is idle, it means that the UE acquires the COT by itself (i.e., the COT initiated by the UE), and the UE continues to perform the first uplink transmission in the COT initiated by the UE (in Fig. 9That is, the UE serves as an initiator device that initiates the first uplink transmission according to the second FFP.

[0110] Next, the UE operates as a responding device initiating a second uplink transmission according to the first FFP. At the start of the next FFP1, the UE assumes that the gNB has successfully performed the second LBT procedure (at Fig. 9 denoted as LBT2 in the figure), and the UE detects a downlink transmission from the cell in the first FFP (in Fig. 9 In response to detecting a downlink transmission, the UE performs a third LBT procedure (in Fig. 9 If the third LBT process indicates that the operating channel is idle, it means that the UE is allowed to share the COT initiated by the gNB and use the uplink resources to perform the second uplink transmission (in Fig. 9 Indicated as ULTx2).

[0111] In one example, the first uplink transmission may include Msg-1 of the contention-based random access procedure, the downlink transmission may include Msg-2 of the contention-based random access procedure, and the second uplink transmission may include Msg-3 of the contention-based random access procedure.

[0112] Fig.10 This is a schematic diagram of supporting UE-initiated COT for FBE operation according to the sixth embodiment of the present application.

[0113] Similar to Fig. 9 In an embodiment of the present invention, the UE first operates as an initiating device for initiating a first uplink transmission according to the second FFP (at Fig.10 Then, in the next FFP1, the responding device operates to initiate a second uplink transmission (in Fig.10 , which is denoted as ULTx2 in the figure, provided that a downlink transmission was previously performed in the same first FFP (in Fig.10 denoted as DLTx1).

[0114] and Fig. 9 Unlike the embodiment of the present invention, the scheduling uplink grant (ie, uplink resource) for the second uplink transmission is configured by the cell to be synchronized with the start time of the second FFP, and the UE can perform the LBT procedure (in advance) once it has been previously performed. Fig.10 If LBT3 is represented in the figure, a second uplink transmission is performed.

[0115] Fig.11 This is a schematic diagram of supporting UE-initiated COT for FBE operation according to the seventh embodiment of the present application.

[0116] Similar to Fig.10 In an embodiment of the present invention, the UE first operates as an initiating device for initiating a first uplink transmission according to the second FFP (at Fig.11 UL Tx1), and then in the next FFP1, operates as a responding device for detecting downlink transmission according to the first FFP (in Fig.11 denoted as DLTx1).

[0117] and Fig.10 Unlike the embodiment of the present invention, the scheduling uplink grant (i.e., uplink resource) for the second uplink transmission is configured in an FFP1 different from the FFP1 in which the downlink transmission occurs. That is, when the first uplink transmission includes Msg-1, the downlink transmission includes Msg-2, and the second uplink transmission includes Msg-3, Msg-1 to Msg-3 of the same RACH process are sent or received in different fixed frame periods.

[0118] Although the present application has been described by way of examples and preferred embodiments, it should be understood that the present application is not limited thereto. Without departing from the scope and spirit of the present application, those skilled in the art can still make various changes and modifications. Therefore, the scope of the present application should be defined and protected by the appended claims and their equivalents.

[0119] The use of ordinal terms such as "first", "second", etc. in the claims to modify claim elements does not in itself imply any priority, precedence, or order of one claim element relative to another claim element or the temporal order in which method actions are performed, but serves merely as a label to distinguish one claim element with a particular name from another element with the same name (but used in ordinal terms) to distinguish the claim elements.

Claims

1. A method for channel access, characterized in that: include: Determine a start time and a period of a first fixed frame period of a first cell on an operating channel of an unlicensed frequency band, wherein the first fixed frame period is used to indicate a channel occupation time initiated by a network node; as well as Determine a start time and period of a second fixed frame period for uplink transmission of the first cell, wherein the second fixed frame period is used for a channel occupancy time initiated by a user equipment for the uplink transmission.

2. The method according to claim 1, characterized in that Also includes: Determining a channel occupancy time period or an idle period of the first fixed frame period; as well as A channel occupation time period or an idle period of the second fixed frame period is determined.

3. The method according to claim 1, characterized in that The period of the second fixed frame period is determined according to at least one of the following: information configured or signaled from the first cell; a period of the first fixed frame period; and A period of one type of uplink resource.

4. The method according to claim 1, characterized in that: The start time of the second fixed frame period is determined according to at least one of the following: information semi-statically configured or dynamically signaled from said first cell; The start time of the first fixed frame period; and The starting time of a type of uplink resource.

5. The method according to claim 1, characterized in that The start time of the second fixed frame period indicates an offset, a system frame boundary, or a system subframe boundary relative to the start time of the first fixed frame period.

6. The method according to claim 2, characterized in that The channel occupation time period or the idle period of the second fixed frame period is determined according to at least one of the following: information semi-statically configured or dynamically signaled from said first cell; A channel occupation time period or an idle period of the first fixed frame period; Predefined rules.

7. The method according to any one of claims 3 and 4, characterized in that: This type of uplink resources includes physical random access channel resources for random access, physical uplink shared channel resources for configuration grants, or physical uplink control channel resources for scheduling requests, channel state information reports, and hybrid automatic repeat request feedback.

8. A device for channel access, characterized in that: include: A wireless transceiver, configured to perform wireless transmission and reception with a first cell of a mobile communication network; as well as A controller, coupled to the wireless transceiver, is used to determine the start time and period of a first fixed frame period of a first cell on an operating channel of an unlicensed frequency band, wherein the first fixed frame period is used to indicate the channel occupancy time initiated by a network node; and is used to determine the start time and period of a second fixed frame period of uplink transmission of the first cell, wherein the second fixed frame period is used for the channel occupancy time initiated by a user equipment for the uplink transmission.

9. The device according to claim 8, characterized in that The controller is further configured to determine a channel occupation time period or an idle period of the first fixed frame period, and determine a channel occupation time period or an idle period of the second fixed frame period.

10. The device according to claim 8, characterized in that The period of the second fixed frame period is determined according to at least one of the following: information configured or signaled from the first cell; a period of the first fixed frame period; and A period of one type of uplink resource.

11. The device according to claim 8, characterized in that The start time of the second fixed frame period is determined according to at least one of the following: information semi-statically configured or dynamically signaled from said first cell; The start time of the first fixed frame period; and The starting time of a type of uplink resource.

12. The device according to claim 8, characterized in that The start time of the second fixed frame period indicates an offset, a system frame boundary, or a system subframe boundary relative to the start time of the first fixed frame period.

13. The device according to claim 9, characterized in that The channel occupation time period or the idle period of the second fixed frame period is determined according to at least one of the following: information semi-statically configured or dynamically signaled from said first cell; A channel occupation time period or an idle period of the first fixed frame period; Predefined rules.

14. The device according to any one of claims 10 and 11, characterized in that: This type of uplink resources includes physical random access channel resources for random access, physical uplink shared channel resources for configuration grants, or physical uplink control channel resources for scheduling requests, channel state information reports, and hybrid automatic repeat request feedback.

15. A method for channel access, characterized in that: include: Determining a fixed frame period for a cell on an operating channel in an unlicensed frequency band; determining whether a downlink transmission from the cell occurs within a first duration after a start time of the fixed frame period to which uplink resources are allocated; and In response to the downlink transmission from the cell occurring within the first duration after the start time of the fixed frame period, uplink transmission to the cell is performed using the uplink resources in the fixed frame period.

16. The method according to claim 15, characterized in that Also includes: performing a listen-before-talk procedure on the operating channel for a second duration before the uplink transmission begins; The uplink transmission is performed in response to the listen-before-talk procedure indicating that the operating channel is idle.

17. The method according to claim 16, characterized in that The listen-before-speak process may be configured as a one-time listen-before-speak process or a non-listen-before-speak process.

18. The method according to claim 15, characterized in that The fixed frame period is determined according to remaining minimum system information or dedicated radio resource control signaling from the cell.

19. A non-transitory machine-readable storage medium, characterized in that Program instructions and data are stored, and when the program instructions and data are executed by a controller of a user equipment operating in a frame-based device mode, the user equipment executes the method as described in any one of claims 1-7, 15-18 above.

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