Method and apparatus for uplink data transmission or reception

Abstract

This application relates to a method and apparatus for uplink data transmission or reception. An embodiment of this application provides a method for uplink data transmission performed by a user equipment (UE), which includes: receiving, from a base station (BS), a first signaling indicating a first channel access priority class value, where the first channel access priority class value is used by the BS to initiate channel occupancy; receiving, from the BS, a second signaling scheduling a physical uplink shared channel (PUSCH) for transmitting uplink data; performing a channel access procedure; and transmitting the uplink data to the BS on the PUSCH in response to the successful completion of the channel access procedure.

Description

Technical Field

[0001] This application relates to the 3rd Generation Partnership Project (3GPP) 5G New Radio (NR), and particularly to a method and apparatus for uplink data transmission or reception. Background Art

[0002] A base station (BS) and a user equipment (UE) can operate in both licensed and unlicensed spectrums. To achieve fair coexistence with other wireless systems, a channel access procedure (e.g., listen-before-talk (LBT)) is required before a transmitter can start transmitting on an unlicensed spectrum. Only when the LBT is successful can the transmitter start transmitting on the channel and occupy the channel up to a maximum channel occupancy time (MCOT); otherwise, the transmitter cannot start transmitting and continues to perform LBT until the LBT is successful.

[0003] Therefore, it is necessary for the UE to know the LBT-related information. Summary of the Invention

[0004] It is desired to provide a solution to indicate LBT-related information to the UE for uplink data transmission.

[0005] An embodiment of this application provides a method for uplink data transmission performed by a user equipment (UE), which includes: receiving a first signaling from a base station (BS) indicating a first channel access priority class value, where the first channel access priority class value is used by the BS to initiate channel occupancy; receiving a second signaling from the BS scheduling a physical uplink shared channel (PUSCH) for transmitting uplink data; performing a channel access procedure; and transmitting the uplink data to the BS on the PUSCH in response to the success of the channel access procedure.

[0006] Another embodiment of this application provides a method for uplink data reception performed by a base station (BS), which includes: transmitting a first signaling to a user equipment (UE) indicating a first channel access priority class value, where the first channel access priority class value is used by the BS to initiate channel occupancy; transmitting a second signaling to the UE scheduling a physical uplink shared channel (PUSCH) for transmitting uplink data; and receiving the uplink data from the UE on the PUSCH.

[0007] Another embodiment of the present application provides a device, comprising: a non-transitory computer-readable medium having computer-executable instructions stored thereon; a receiving circuit system; a transmitting circuit system; and a processor coupled to the non-transitory computer-readable medium, the receiving circuit system, and the transmitting circuit system, wherein the computer-executable instructions cause the processor to implement the method, the method comprising: receiving, from a base station (BS), first signaling indicating a first channel access priority class value, wherein the first channel access priority class value is used by the BS to initiate channel occupancy; receiving, from the BS, second signaling scheduling a physical uplink shared channel (PUSCH) for transmitting uplink data; performing a channel access procedure; and in response to a successful channel access procedure, transmitting the uplink data to the BS on the PUSCH.

[0008] Another embodiment of the present application provides a device, comprising: a non-transitory computer-readable medium having computer-executable instructions stored thereon; a receiving circuit system; a transmitting circuit system; and a processor coupled to the non-transitory computer-readable medium, the receiving circuit system, and the transmitting circuit system, wherein the computer-executable instructions cause the processor to implement the method, the method comprising: transmitting, to a user equipment (UE), first signaling indicating a first channel access priority class value, wherein the first channel access priority class value is used by the BS to initiate channel occupancy; transmitting, to the UE, second signaling scheduling a physical uplink shared channel (PUSCH) for transmitting uplink data; and receiving, on the PUSCH, the uplink data from the UE. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 A schematic diagram illustrating a wireless communication system according to some embodiments of the present disclosure.

[0010] Figure 2 Illustrating scheduled PUSCH transmission within a gNB-initiated channel occupancy time (COT) according to a preferred embodiment of the present disclosure.

[0011] Figure 3 Illustrating scheduled PUSCH transmission outside of a gNB-initiated COT according to a preferred embodiment of the present disclosure.

[0012] Figure 4 Illustrating configured grant (CG) PUSCH transmission within a gNB-initiated COT according to a preferred embodiment of the present disclosure.

[0013] Figure 5 Illustrating CG-PUSCH transmission outside of a gNB-initiated COT according to a preferred embodiment of the present disclosure.

[0014] Figure 6 Describe a method for uplink data transmission performed by a UE according to a preferred embodiment of the present disclosure.

[0015] Figure 7 Describe a method for uplink data reception performed by a BS according to a preferred embodiment of the present disclosure.

[0016] Figure 8 Describe a block diagram of a UE according to a preferred embodiment of the present disclosure.

[0017] Figure 9 Describe a block diagram of a BS according to a preferred embodiment of the present disclosure. Detailed Description of the Invention

[0018] The detailed description of the drawings is intended as a description of the currently preferred embodiments of the present invention and is not intended to represent the only form in which the present invention may be practiced. It should be understood that the same or equivalent functions may be accomplished by different embodiments that are intended to be covered within the spirit and scope of the present invention.

[0019] Embodiments provide a method and apparatus for downlink (DL) or uplink (UL) data transmission on an unlicensed spectrum. For purposes of facilitating understanding, the embodiments are provided in the context of a particular network architecture and new service scenarios (such as 3GPP 5G, 3GPP LTE Release 8, etc.). As is well known to those skilled in the art, as network architectures and new service scenarios are developed, the embodiments in the present disclosure may also be applicable to similar technical problems.

[0020] Figure 1 Depict a wireless communication system 100 according to an embodiment of the present disclosure.

[0021] As Figure 1 shown, the wireless communication system 100 includes a UE 101 and a BS 102. Specifically, for illustrative purposes, the wireless communication system 100 includes three UEs 101 and three BSs 102. Although a specific number of UEs 101 and BSs 102 are depicted in Figure 1 , those skilled in the art will recognize that any number of UEs 101 and BSs 102 may be included in the wireless communication system 100.

[0022] The UE 101 may include a computing device, such as a desktop computer, a laptop computer, a personal digital assistant (PDA), a tablet computer, a smart TV (e.g., a TV connected to the Internet), a set-top box, a gaming console, a security system (including security cameras), an in-vehicle computer, a network device (e.g., a router, a switch, and a modem), or the like. According to an embodiment of the present disclosure, the UE 101 may include a portable wireless communication device, a smart phone, a cellular phone, a flip phone, a device with a subscriber identity module, a personal computer, a pager, or any other device capable of transmitting communication signals over a wireless network and receiving communication signals over the wireless network. In some embodiments, the UE 101 includes a wearable device, such as a smart watch, a fitness band, an optical head-mounted display, or the like. Additionally, the UE 101 may be referred to as a user unit, a mobile device, a mobile station, a user, a terminal, a mobile terminal, a wireless terminal, a fixed terminal, a user station, a user terminal, or a device, or other terms used in the art. The UE 101 may communicate directly with the BS 102 via an uplink (UL) communication signal.

[0023] The BSs 102 may be distributed throughout a geographical area. In certain embodiments, each of the BSs 102 may also be referred to as an access point, an access terminal, a base station, a macro cell, a Node-B, an evolved Node B (eNB), a gNB, a home Node-B, a repeater node, or a device, or other terms used in the art. The BS 102 is generally part of a radio access network that may include one or more controllers communicatively coupled to one or more corresponding BSs 102.

[0024] The wireless communication system 100 is compatible with any type of network capable of transmitting and receiving wireless communication signals. For example, the wireless communication system 100 is compatible with a wireless communication network, a cellular phone network, a time division multiple access (TDMA)-based network, a code division multiple access (CDMA)-based network, an orthogonal frequency division multiple access (OFDMA)-based network, an LTE network, a 3GPP-based network, a 3GPP 5G network, a satellite communication network, a high altitude platform network, and / or other communication networks.

[0025] In one embodiment, the wireless communication system 100 is compatible with 5G New Radio (NR) of the 3GPP protocol, where the BS 102 transmits data using an orthogonal frequency division multiplexing (OFDM) modulation scheme on the downlink, and the UE 101 transmits data using a discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM) or a cyclic prefix orthogonal frequency division multiplexing (CP-OFDM) scheme on the uplink. However, more generally, the wireless communication system 100 may implement some other open or proprietary communication protocols, such as WiMAX, and other protocols.

[0026] In other embodiments, the BS 102 may communicate using other communication protocols (e.g., wireless communication protocols of the IEEE 802.11 series). Additionally, in some embodiments, the BS 102 may communicate via licensed spectrum, while in other embodiments, the BS 102 may communicate via unlicensed spectrum. The present disclosure is not intended to be limited to the implementation of any particular wireless communication system architecture or protocol. In another embodiment, the BS 102 may communicate with the UE 101 using the 3GPP 5G protocol.

[0027] In Rel-14 LTE eLAA, the following fields are included in the DCI for scheduling PUSCH transmission:

[0028] - Channel Access Priority Class (CAPC) (2 bits)

[0029] - Channel Access Type (1 bit)

[0030] - PUSCH Starting Position (2 bits)

[0031] The Channel Access Type field indicates the type of LBT performed by the UE before PUSCH transmission. The two-bit Channel Access Priority Class indicates the priority class value used by the gNB to initiate the COT.

[0032] The channel access procedure includes various types of operations. For example, one type of operation is the LBT Category 4 operation with a random backoff counter selected from a variable contention window (hereinafter referred to as LBT Cat.4 in the present disclosure) (also referred to as Type 1 UL channel access procedure in TS37.213). Another type of operation is the LBT Category 2 operation (hereinafter referred to as LBT Cat.2 in the present disclosure), which is also referred to as Type 2 UL channel access procedure in TS37.213. With LBT Cat.2, the UE can transmit immediately after a sensing interval of sensing the channel idle for at least 25 microseconds. An LBT Cat.2 with a sensing interval of 16 microseconds is also supported. Another type of operation is the LBT Category 1 operation, for which LBT operation is not recommended.

[0033] In TS37.213, there are four existing UL CAPC values: 1, 2, 3, and 4, for LBT Cat.4 (i.e., UL Type 1 channel access procedure). Each UL CAPC value corresponds to a specific contention window for generating a random backoff counter. The priority of the CAPC is inversely proportional to the CAPC value. For example, the priority of data with a CAPC value of 4 is lower than that of data with a CAPC value of 1, 2, or 3.

[0034] If the DCI instructs the UE to perform LBT Cat.4 and the scheduled PUSCH is within the COT initiated by the gNB, then the UE will compare the CAPC value indicated in the DCI (referred to as the first CAPC value) with the CAPC value of the uplink data (referred to as the second CAPC value). If the second CAPC value is less than or equal to the first CAPC value, in other words, the priority of the uplink data to be transmitted by the UE is higher than or equal to the priority indicated in the UL grant, then the UE will switch LBT Cat.4 to LBT Cat.2 and transmit the uplink data on the PUSCH. If the second CAPC value is greater than the first CAPC value, in other words, the priority of the uplink data to be transmitted by the UE is lower than the priority indicated in the UL grant, then the UE should terminate the PUSCH transmission.

[0035] If the DCI instructs the UE to perform LBT Cat.4 and the scheduled PUSCH is outside the COT initiated by the gNB, then the UE will perform LBT Cat.4 with the first CAPC value indicated in the DCI before the PUSCH transmission.

[0036] However, when the gNB prepares the content of the DCI or UL grant, it may not be able to accurately know the buffer status of the UE's uplink data or the quality of service (QoS) of the service. Therefore, the gNB may not be able to predict the CAPC value of the uplink data stored in the UE's buffer, which will be transmitted via the unlicensed carrier. Therefore, it may be impractical for the gNB to indicate an appropriate CAPC value in the UL grant, especially when the UE supports multiple service QoS flows.

[0037] In addition, when the gNB prepares the content of the DCI or UL grant, it may not know whether the scheduled PUSCH is within or outside the COT initiated by the gNB. For example, due to scheduling the PUSCH in the UL burst after the DL burst, the time offset between the UL grant and the scheduled PUSCH may be quite long. For another example, the gNB performs one channel access procedure only for transmitting the UL grant and another channel access procedure for transmitting the DL transmission. Under this condition, the new COT initiated by the gNB may overlap with the scheduled PUSCH.

[0038] Assume that the gNB scheduling is considered for a PUSCH outside the gNB's ongoing COT. Then, the CAPC value in the UL grant indicates the CAPC value that will be used by the UE to initiate the COT. However, if the scheduled PUSCH falls within the gNB-initiated COT (the COT may be the same or different from the gNB-initiated COT used to transmit the UL grant), then the UE considers the CAPC value in the UL grant as the CAPC value used by the gNB to initiate the COT. In this sense, in the case where the CAPC value of the uplink data is greater than the CAPC indicated in the UL grant, the UE may terminate its UL transmission. In other words, the CAPC value in the UL grant configured by the gNB is intended to be the second CAPC value for the UE to initiate the COT, while the UE considers the CAPC value as the first CAPC value used by the gNB to initiate the COT. This results in a misunderstanding of the CAPC value between the gNB and the UE.

[0039] In addition, it also imposes unnecessary complexity on the gNB because the gNB is required to track the buffer status report (BSR) and traffic QoS of the uplink received data to determine the second CAPC value of the UE. Furthermore, in the case of specifying autonomous uplink (AUL) transmission in LTE Rel-15 FeLAA, the UE is already able to select the correct CAPC value based on the content of the uplink data to be transmitted. This mechanism is completely under network control because the network maps the logical channels to the channel access priority class values. In this sense, it is preferable to have a unified solution for the CAPC value for the UE to determine both the uplink dynamic scheduling and the configured grant.

[0040] In the present disclosure, we focus on the signaling details for LBT type indication and provide several embodiments. Specifically, the present disclosure focuses on determining the CAPC value and the LBT type.

[0041] Since the existing CAPC values include four values: 1, 2, 3, and 4, 2 bits are needed to indicate the CAPC value. The LBT types included in the present disclosure include four types: LBT Cat.1, LBT Cat.2 with a sensing interval of 16 us, LBT Cat.2 with a sensing interval of 25 us, and LBT Cat.4. Therefore, 2 bits are also needed to indicate the LBT type.

[0042] Figure 2 Describe the scheduled PUSCH transmission within the gNB-initiated COT according to a preferred embodiment of the present disclosure. In Figure 2Among them, the gNB starts the channel occupancy rate 200, and the UL grant 201-1 schedules the PUSCH 202-1, which is within the COT 200 started by the gNB and at the start of the UL burst 202. The offset is between the end of the DL burst 201 and the start of the UL burst 202.

[0043] In a preferred embodiment, the present disclosure proposes that the UL grant 201-1 neither indicates the LBT type nor indicates the CAPC value. LBT Cat.4 is regarded as the default LBT type for uplink PUSCH transmission. Two bits are saved for indicating the CAPC value and two bits are saved for indicating the LBT type. Therefore, in this embodiment, four bits are saved in the UL grant.

[0044] In this embodiment, the UE determines the CAPC value (referred to as the second CAPC value, or UL CAPC value) used by the UE to perform LBT Cat.4 based on the uplink service data. The gNB can indicate the CAPC value (referred to as the first CAPC value, or DL CAPC value) used by the gNB to start the COT of the gNB in a cell-specific manner. For example, the first CAPC value can be indicated in the group common physical downlink control channel (PDCCH) indicating the structure of the COT of the gNB (for example, the duration of the DL burst, the duration of the UL burst, and the duration of the offset between the DL burst and the UL burst), the DCI format 2_0 for transmitting the slot format information (SFI), or any other common PDCCH.

[0045] The presence of the first CAPC field in the UL grant is explicitly configured by radio resource control (RRC) signaling. That is, if the RRC signaling configures the UL grant to include the first CAPC field, then the UL grant includes the first CAPC value used by the gNB to start the COT of the gNB. Under this condition, the UL grant includes two bits for indicating the first CAPC value.

[0046] Alternatively, the presence of the first CAPC field in the UL grant depends on whether the gNB is willing to share its COT for the UE to perform uplink data transmission. If the gNB configuration allows downlink-to-uplink (DL to UL) sharing, in other words, the gNB is willing to share its COT for the UE to perform uplink data transmission, then the UE considers the UL grant to include the first CAPC field. This field indicates the first CAPC value used by the gNB to start the COT of the gNB. In this case, the UL grant also includes two bits for indicating the CAPC value. If the gNB configuration does not allow DL to UL sharing, then the UE considers the UL grant not to include the first CAPC field. In this embodiment, two bits are saved for indicating the CAPC value.

[0047] Based on COT structure signaling, SFI, or any other information, the UE can derive information about UL burst 202 within the gNB-initiated COT 200, such as the offset between the end of DL burst 201 and the start of UL burst 202, the duration of UL burst 202, etc. Thus, the UE can determine whether the scheduled PUSCH 202-1 is within or outside the gNB-initiated COT 200.

[0048] If the UE determines that the scheduled PUSCH 202-1 is within the gNB-initiated COT 200, then the UE shall perform LBT Cat.2 before PUSCH transmission. For example, in Figure 2 the scheduled PUSCH 202-1 is within the gNB-initiated COT 200, and the UE will perform LBT Cat.2 before PUSCH transmission.

[0049] If the first CAPC value used by the gNB is higher than or equal to the second CAPC value of the uplink data, i.e., the priority of the gNB's downlink data is lower than or equal to the priority of the UE's uplink data, then the UE shall transmit the uplink data on the scheduled PUSCH. If the first CAPC value is lower than the second CAPC value, i.e., the priority of the gNB's downlink data is higher than the priority of the UE's uplink data, then the UE shall terminate transmitting the uplink data on the scheduled PUSCH.

[0050] Alternatively, if the UE determines that the scheduled PUSCH 202-1 is within the gNB-initiated COT 200, then the UE shall perform LBT Cat.2 before PUSCH transmission. The UE shall only multiplex data (MAC SDU) of the logical channel (LCH) into the PUSCH for the corresponding transport block (TB) / MAC PDU, where the transport block (TB) / MAC PDU has an associated CAPC value that is equal to or lower than the CAPC value used by the gNB.

[0051] For the LCP process, basically only the LCH that satisfies the CAPC condition (i.e., the associated CAPC value is equal to or lower than the CAPC value used by the gNB) is considered, i.e., the MAC layer performs LCH restriction according to the CAPC value used by the gNB. Similar to the LCH, the mapping of MAC control elements to PUSCH resources can also be restricted based on the CAPC value. The assumption here is that each MAC CE has an associated CAPC value.

[0052] It should be noted that the LCP procedure is only performed for the initial transmission. Therefore, in the case where the scheduled PUSCH carrying the HARQ retransmission falls within the gNB-initiated COT, the following behavior may be applied: If the CAPC value used by the gNB is higher than or equal to the CAPC value of the MAC PDU (uplink data), then the UE shall transmit the retransmission on the scheduled PUSCH; if the CAPC value used by the gNB is lower than the CAPC value of the MAC PDU (uplink data), then the UE shall terminate transmitting the retransmission on the scheduled PUSCH.

[0053] Alternatively, the HARQ retransmission may be transmitted on the scheduled PUSCH regardless of the CAPC value of the MAC PDU, i.e., the UE always transmits the PUSCH.

[0054] In Figure 2 , the offset located between the end of the DL burst 201 and the start of the UL burst 202 within the gNB-initiated COT 200 is indicated in the COT structure signaling, the DCI format 2_0 of the SFI, or a field included in other common PDCCHs. The offset may be indicated by a number of time slots or a number of symbols. For example, the offset may include 4 time slots and / or 10 symbols. The offset may be indicated by some predefined states. For example, at least three predefined states: the first state indicates that the offset is shorter than 16 us, the second state indicates that the offset is equal to 16 us, and the third state indicates that the offset is longer than 16 us or 25 us and shorter than one symbol; other states may indicate the offset in time slots or symbols.

[0055] Alternatively, the COT structure signaling, the DCI format 2_0 of the SFI, or other common PDCCH may include two fields to indicate the offset. The first field indicates the offset in units of time slots or symbols, and the second field indicates the offset from a set of states. For example, the second field indicates one of at least three states: the first state indicates that the offset is shorter than 16 us, the second state indicates that the offset is equal to 16 us, and the third state indicates that the offset is longer than 16 us or 25 us.

[0056] In some embodiments, the offset determines the type of LBT performed by the UE. In Figure 2In it, if the UE determines that the scheduled PUSCH 202-1 is within the gNB-initiated COT 200, and if the indicated offset is shorter than 16 us and the scheduled PUSCH is located at the start of the UL burst, then the UE shall transmit the PUSCH without performing LBT, that is, perform LBT Cat.1. If the indicated offset is equal to 16 us and the scheduled PUSCH is located at the start of the UL burst, then the UE shall perform LBT Cat.2 with a duration of 16 us before transmitting the PUSCH. If the indicated offset is longer than 16 us or 25 us, then the UE shall perform LBT Cat.2 with a duration of 25 us before transmitting the PUSCH. Note that the gNB shall not configure an offset with a duration longer than 16 us and shorter than 25 us.

[0057] Figure 3 Describe the scheduled PUSCH transmission outside the gNB-initiated COT 301 according to a preferred embodiment of the present disclosure.

[0058] If the UE determines that the scheduled PUSCH 302-1 is outside the gNB-initiated COT 301, or the UE cannot determine whether its scheduled PUSCH 302-1 is part of the shared gNB-initiated COT 301, then the UE shall perform LBT Cat.4 before PUSCH transmission. The second CAPC value for LBT Cat.4 is determined by the UE based on the uplink data. Alternatively, the rule or configuration may force the UE to always use the CAPC value 4, that is, the highest value that allows the longest COT and allows multiplexing of any data.

[0059] Figure 4 Describe the CG-PUSCH transmission within the gNB-initiated COT according to a preferred embodiment of the present disclosure.

[0060] In Figure 4 the CG-PUSCH 402-1 falls within the gNB-initiated COT 400, and the UE determines whether it can transmit the CG-PUSCH by comparing the first CAPC value used by the gNB to initiate the COT with the second CAPC value of the uplink data.

[0061] The first CAPC value used by the gNB to initiate the COT is indicated in a cell-specific manner, for example, the group common PDCCH indicating the structure of the gNB's COT (such as the DL burst duration, UL burst duration, and the duration of the offset between the DL burst and the UL burst), the DCI format 2_0 for transmitting the SFI, or any other common PDCCH.

[0062] If the first CAPC value is higher than or equal to the second CAPC value of the uplink data, the UE shall transmit the uplink data on the CG-PUSCH; if the first CAPC value is lower than the second CAPC value of the uplink data, the UE shall terminate transmitting the uplink data on the CG-PUSCH.

[0063] In Figure 4 the UE determines that the CG-PUSCH 402-1 falls within the gNB-initiated COT 400, and the UE determines the LBT type based on the offset. The determination is similar to Figure 2 the determination in, that is, if the indicated offset is shorter than 16 us and the CG-PUSCH is located at the start of the UL burst 402, the UE shall transmit the CG-PUSCH without performing LBT, that is, perform LBT Cat.1. If the indicated offset is equal to 16 us and the CG-PUSCH is located at the start of the UL burst, the UE shall perform LBT Cat.2 for a duration of 16 us before transmitting the CG-PUSCH. If the indicated offset is longer than 16 us or 25 us, the UE shall perform LBT Cat.2 for a duration of 25 us before transmitting the CG-PUSCH. We believe that the gNB should not perform an offset with a duration longer than 16 us and shorter than 25 us.

[0064] Figure 5 Describe CG-PUSCH transmission outside the gNB-initiated COT according to a preferred embodiment of the present disclosure.

[0065] If the UE determines that the CG-PUSCH 502-1 is outside the gNB-initiated COT 501, or the UE cannot determine whether its CG-PUSCH 502-1 is part of the shared gNB-initiated COT 501, the UE shall perform LBT Cat.4 before PUSCH transmission. The second CAPC value for LBT Cat.4 is determined by the UE based on the uplink data. Alternatively, the rule or configuration may force the UE to always use the CAPC value 4, that is, the highest value that allows the longest COT and allows multiplexing of any data.

[0066] In another preferred embodiment, the UL grant includes a one-bit indicator to indicate whether the scheduled PUSCH is within or outside the gNB-initiated COT. The UL grant neither indicates the LBT type nor the CAPC value. Save 2 bits for indicating the CAPC value and 2 bits for indicating the LBT type. Therefore, in this embodiment, at least 3 bits are saved in the UL grant.

[0067] In one embodiment, the gNB may indicate the first CAPC value in a manner similar to the indication manner in Figure 2 the embodiment.

[0068] Alternatively, the presence of the first CAPC field used by the gNB to initiate the gNB's COT in the UL grant is explicitly configured by RRC signaling. Alternatively, the presence of the first CAPC field in the UL grant depends on whether the gNB is willing to share its COT for the UE to perform uplink data transmission. Note that under this condition, the 2 bits used to indicate the first CAPC value are not saved, so 1 bit is saved in the UL grant.

[0069] Based on the one-bit indicator, the UE can clearly know whether the scheduled PUSCH is within or outside the COT initiated by the gNB, and the UE can determine the LBT type according to whether the scheduled PUSCH is within or outside the COT initiated by the gNB.

[0070] For example, similar to Figure 2 in the embodiment, if the UE determines that the scheduled PUSCH 202-1 is within the COT200 initiated by the gNB, then the UE shall perform LBT Cat.2 before PUSCH transmission. If the first CAPC value used by the gNB is higher than or equal to the second CAPC value of the uplink data, then the UE shall transmit the uplink data on the scheduled PUSCH. If the first CAPC value used by the gNB is lower than the CAPC value of the uplink data, then the UE will terminate transmitting the uplink data on the scheduled PUSCH.

[0071] For another example, similar to Figure 3 in the embodiment, if the UE determines that the scheduled PUSCH 302-1 is outside the COT 300 initiated by the gNB, then the UE shall perform LBT Cat.4 before PUSCH transmission. The second CAPC value for LBT Cat.4 is determined by the UE based on the uplink data.

[0072] In this embodiment, the UE determines the LBT type in a manner similar to Figure 2 in the embodiment, that is, the UE determines the LBT type based on the comparison between the first CAPC value and the second CAPC value. Alternatively, the UE also determines the LBT type based on the offset in a manner similar to Figure 2 the embodiment disclosed in

[0073] In another preferred embodiment, the UL grant includes a one-bit indicator for indicating the LBT type. Specifically, the bit indicates whether the channel access procedure is LBT Cat.4. The UL grant does not indicate the CAPC value. The 2 bits for indicating the CAPC value and the 1 bit for indicating the LBT type are saved. Therefore, in this embodiment, 3 bits are saved in the UL grant.

[0074] In this embodiment, the second CAPC value for LBT Cat.4 is determined by the UE based on uplink data, and the first CAPC value is indicated in a manner similar to the indication method in the embodiment in Figure 2 .

[0075] Alternatively, the presence of the first CAPC field in the UL grant depends on whether the gNB is willing to share its COT for the UE to perform uplink data transmission. Note that under this condition, the 2 bits used to indicate the first CAPC value are not saved, so 1 bit is saved in the UL grant.

[0076] In this embodiment, based on COT structure signaling, SFI, or any other information, the UE can derive UL burst information within the COT initiated by the gNB. For example, the offset between the end of the DL burst and the start of the UL burst, the duration of the UL burst, etc. Therefore, the UE can determine whether the scheduled PUSCH is within or outside the COT initiated by the gNB.

[0077] Based on whether the scheduled PUSCH is within or outside the COT initiated by the gNB, the UE determines the LBT type in a manner similar to the embodiment disclosed in Figure 2 , that is, the UE determines the LBT type based on the comparison between the first CAPC value and the second CAPC value. Alternatively, the UE determines the LBT type based on the offset, which is also similar to the embodiment disclosed in Figure 2 .

[0078] Similar to the embodiment in Figure 3 , if the UE determines that the scheduled PUSCH 302-1 is outside the COT 300 initiated by the gNB, then the UE shall perform LBT Cat.4 before PUSCH transmission. The second CAPC value for LBT Cat.4 is determined by the UE based on uplink data.

[0079] In another preferred embodiment, the UL grant contains one bit for indicating whether the LBT type is LBT Cat.4 or non-Cat.4, and the information indicated by the other two bits depends on the LBT type. If the LBT type is LBT Cat.4, then the other two bits in the UL grant indicate the first CAPC value used by the gNB to initiate the COT. If the LBT type is not LBT Cat.4, then the other two bits indicate that the offset between the end of the DL burst and the start of the UL burst within the COT initiated by the gNB is shorter than 16 us, equal to 16 us, or longer than 16 us or 25 us, etc.

[0080] When LBT Cat.4 is indicated in the UL grant, the first CAPC value is indicated by two bits in the UL grant. The UE can derive the UL burst information within the gNB-initiated COT based on COT structure signaling, SFI, etc. Therefore, the UE can determine whether the scheduled PUSCH is within or outside the gNB-initiated COT.

[0081] If the UE determines that the scheduled PUSCH is within the gNB-initiated COT, then the UE performs LBT Cat.2 for a duration of 25 us before PUSCH transmission. If the CAPC value used by the gNB is higher than or equal to the CAPC value of the uplink data, then the UE shall transmit the uplink data on the scheduled PUSCH; if the CAPC value used by the gNB is lower than the CAPC value of the uplink data, then the UE shall terminate transmitting the uplink data on the scheduled PUSCH.

[0082] If the UE determines that the scheduled PUSCH is outside the gNB-initiated COT, then the UE shall perform LBT Cat.4 before PUSCH transmission. The CAPC value for LBT Cat.4 is determined by the UE based on the uplink data. Therefore, the 2 bits used to indicate the CAPC value in the UL grant are reserved.

[0083] When non-LBT Cat.4 is indicated in the UL grant, the DL to UL offset is indicated by two bits in the UL grant. The UE can determine the LBT type based on the offset or the DL to UL gap. That is, if the indicated offset is shorter than 16 us and the scheduled PUSCH is located at the start of the UL burst, then the UE shall transmit the PUSCH without performing LBT, i.e., perform LBT Cat.1. If the indicated offset is equal to 16 us and the scheduled PUSCH is located at the start of the UL burst, then the UE shall perform LBT Cat.2 for a duration of 16 us before transmitting the PUSCH. If the indicated offset is longer than 16 us or 25 us, then the UE shall perform LBT Cat.2 for a duration of 25 us before transmitting the PUSCH. Note that the gNB shall not configure an offset with a duration longer than 16 us and shorter than 25 us.

[0084] Figure 6Describe a method for uplink data transmission performed by a UE according to a preferred embodiment of the present disclosure. In step 601, the UE receives first signaling from the BS indicating a first CAPC value. For example, the first signaling may be a group common PDCCH indicating the structure of the COT of the gNB (e.g., DL burst duration, UL burst duration, and the duration of the offset between the DL burst and the UL burst), a group common PDCCH indicating slot format information, or other common PDCCH. The first CAPC category value is used by the BS to initiate channel occupancy. In step 602, the UE receives second signaling from the BS scheduling a PUSCH for transmitting uplink data. For example, the signaling may be Figure 2 DCI 201-1 in

[0085] Figure 7 or RRC signaling for configured grant PUSCH transmission. In step 603, the UE performs a channel access procedure, e.g., LBT Cat.4; and in step 604, in response to the successful channel access procedure, the UE transmits uplink data to the BS on the PUSCH. The first signaling may be indicated in the common PDCCH. Figure 3 DCI 301-1 in Figure 2 or RRC signaling for configured grant PUSCH transmission. In step 703, the BS receives uplink data from the UE. The BS may transmit the

[0086] offset in

[0087] to the UE. Figure 2 In one embodiment, the channel access procedure is LBT Cat.4 with a random backoff counter selected from a variable contention window. The UE uses a second CAPC value corresponding to the uplink data to perform LBT Cat.4.

[0088] In one embodiment, if the second CAPC value is greater than the first CAPC value, then uplink data is not transmitted within COT 200; if the CAPC value is less than or equal to the first CAPC value, then uplink data is transmitted within COT 200.

[0089] In another embodiment, the minimum sensing interval (e.g., 16 us or 25 us) of the channel access procedure is determined based on the offset between a downlink transmission burst within channel occupancy and a subsequent uplink transmission burst. In Figure 2 it, the offset is between the end of DL burst 201 and the start of UL burst 202. If the offset is 16 us, then the minimum detection interval is 16 us, and if the offset is longer than 16 us, then the minimum sensing interval is 25 us. The offset can be indicated by a number of time slots or symbols in DCI 201-1. Alternatively, the offset can be indicated from a set of predefined states in 201-1.

[0090] In one embodiment, the presence of the first CAPC value in DCI is configured by RRC signaling; alternatively, the presence of the first CAPC value in DCI is determined by whether the BS allows uplink transmission within the COT.

[0091] In a preferred embodiment, the DCI also indicates whether the scheduled PUSCH is within or outside the channel occupancy. For example, Figure 2 the DCI 201-1 in it indicates that the scheduled PUSCH is within COT 200, and Figure 3 the DCI 301-1 in it indicates that the scheduled PUSCH is outside COT 301. The DCI can also indicate whether the channel access procedure is a type 1 channel access procedure with a random backoff counter generated within the window, i.e., whether the channel access procedure is LBT Cat.4. If the channel access procedure is LBT Cat.4, then the DCI further indicates the first CAPC value. If the channel access procedure is not LBT Cat.4, then the DCI further indicates the offset, e.g., Figure 2 the offset in it.

[0092] Figure 8 A block diagram of a UE according to an embodiment of the present disclosure is illustrated. UE 101 may include a receiving circuitry, a processor, and a transmitting circuitry. In one embodiment, UE 101 may include: a non-transitory computer-readable medium having computer-executable instructions stored thereon; a receiving circuitry; a transmitting circuitry; and a processor coupled to the non-transitory computer-readable medium, the receiving circuitry, and the transmitting circuitry. The computer-executable instructions may be configured to implement a method using the receiving circuitry, the transmitting circuitry, and the processor (e.g., Figure 6The method in [ ]. That is, when executing computer-executable instructions, the receiving circuitry can receive, from the BS, a first signaling indicating a first CAPC value. For example, the first signaling can be a group common PDCCH indicating the structure of the COT of the gNB (e.g., DL burst duration, UL burst duration, and the duration of the offset between the DL burst and the UL burst), a group common PDCCH indicating slot format information, or other common PDCCH, and the first CAPC class value is used by the BS to initiate channel occupancy. Further, the receiving circuitry can receive, from the BS, a second signaling scheduling the PUSCH for transmitting uplink data. For example, the signaling can be Figure 2 DCI 201-1 in [ ] or RRC signaling for configured grant PUSCH transmission. The processor of the UE performs a channel access procedure, such as LBT Cat.4; and the transmitting circuitry transmits uplink data to the BS on the PUSCH in response to the successful channel access procedure.

[0093] Figure 9 Block diagram of a BS according to an embodiment of the present disclosure. The BS 102 can include a receiving circuitry, a processor, and a transmitting circuitry. In one embodiment, the BS can include: a non-transitory computer-readable medium having computer-executable instructions stored thereon; a receiving circuitry; a transmitting circuitry; and a processor coupled to the non-transitory computer-readable medium, the receiving circuitry, and the transmitting circuitry. The computer-executable instructions can be configured to implement a method (e.g., the method in [ ]) using the receiving circuitry, the transmitting circuitry, and the processor. That is, when executing the computer-executable instructions, the transmitting circuitry can transmit, from the BS, a first signaling indicating a first CAPC value. For example, the first signaling can be a group common PDCCH indicating the structure of the COT of the gNB (e.g., DL burst duration, UL burst duration, and the duration of the offset between the DL burst and the UL burst), a group common PDCCH indicating slot format information, or other common PDCCH, and the first CAPC class value is used by the BS to initiate channel occupancy. Further, the transmitting circuitry can also transmit, from the BS, a second signaling scheduling the PUSCH for transmitting uplink data. For example, Figure 7 DCI 301-1 in [ ] or RRC signaling for configured grant PUSCH transmission. The receiving circuitry can receive uplink data from the UE. Figure 3 The method in [ ].

[0094] The methods of the present disclosure may be implemented on a programmed processor. However, the controller, flowcharts, and modules may also be implemented on a general or special purpose computer, a programmed microprocessor or microcontroller and peripheral integrated circuit elements, an integrated circuit, a hardware electronic or logic circuit (such as a discrete element circuit), a programmable logic device, or the like. Generally, any device having a finite state machine capable of implementing the flowcharts shown in the figures may be used to implement the processing functions of the present disclosure.

[0095] Although the present disclosure has been described with reference to specific embodiments of the present disclosure, it is apparent that many alternatives, modifications, and variations will be apparent to those skilled in the art. For example, the various components of the embodiments may be interchanged, added, or substituted in other embodiments. Moreover, all of the elements shown in each figure are not necessary for the operation of the disclosed embodiments. For example, those skilled in the art of the disclosed embodiments will be able to make and use the teachings of the present disclosure by simply employing the elements of the independent claims. Accordingly, the embodiments of the present disclosure set forth herein are intended to be illustrative and not restrictive. Various changes may be made without departing from the spirit and scope of the present disclosure.

[0096] In the present disclosure, relative terms such as "first", "second", and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. The terms "comprise / comprising" or any other variation thereof are intended to cover non-exclusive inclusion such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element that begins with "a / an" or the like (without further limitation) does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element. Moreover, the term "another" is defined as at least a second or more. As used herein, the terms "including", "having", and the like are defined as "comprising".

Claims

1. A method for uplink data transmission performed by a user equipment UE, comprising: Receiving, from a base station BS, a first signaling indicating the presence of a first channel access priority class value in a second signaling, wherein the first channel access priority class value is used by the BS to initiate channel occupancy; Receiving, from the BS, the second signaling that indicates the first channel access priority class value and schedules a physical uplink shared channel PUSCH for transmitting uplink data; Performing a channel access procedure; and In response to the successful completion of the channel access procedure, transmitting the uplink data to the BS on the PUSCH.

2. The method according to claim 1, wherein the channel access procedure is a type 1 channel access procedure with a random backoff counter generated within a window.

3. The method according to claim 2, wherein a second channel access priority class value corresponding to the uplink data is used to perform the type 1 channel access procedure.

4. The method according to claim 1, wherein in response to the uplink data being to be transmitted within the channel occupancy, the channel access procedure is a type 2 channel access procedure with a minimum sensing interval.

5. The method according to claim 4, wherein in response to a second channel access priority class value corresponding to the uplink data being greater than the first channel access priority class value, the uplink data is not transmitted within the channel occupancy.

6. The method according to claim 4, wherein in response to a second channel access priority class value corresponding to the uplink data being less than or equal to the first channel access priority class value, the uplink data is transmitted within the channel occupancy.

7. The method according to claim 4, wherein the minimum sensing interval is determined based on an offset between a downlink transmission burst and a subsequent uplink transmission burst within the channel occupancy.

8. The method according to claim 7, wherein the offset is indicated by a number of time slots or a number of symbols in downlink control information DCI.

9. The method according to claim 7, wherein the offset is indicated from a set of predefined states in downlink control information DCI.

10. The method according to claim 4, wherein in response to an offset between the second signaling and the PUSCH being 16 microseconds, the minimum sensing interval is 16 microseconds.

11. The method according to claim 4, wherein in response to an offset between the second signaling and the PUSCH being longer than 16 microseconds, the minimum sensing interval is 25 microseconds.

12. The method according to claim 1, wherein the first signaling is indicated in common physical downlink control information PDCCH.

13. The method according to claim 1, wherein the presence of the first channel access priority class value in the second signaling is configured by RRC signaling.

14. The method according to claim 1, wherein the presence of the first channel access priority class value in the second signaling is determined by whether uplink transmission within the channel occupancy is allowed.

15. The method according to claim 1, wherein the second signaling further indicates whether the scheduled PUSCH is within or outside the channel occupancy.

16. The method according to claim 1, wherein the second signaling further indicates whether the channel access procedure is a type 1 channel access procedure with a random backoff counter generated within a window.

17. The method according to claim 16, wherein in response to the second signaling further indicating that the channel access procedure is the type 1 channel access procedure, the second signaling further indicates the first channel access priority class value.

18. The method according to claim 16, wherein in response to the second signaling further indicating that the channel access procedure is not the type 1 channel access procedure, the second signaling further indicates the offset between a downlink transmission burst within the channel occupancy and a subsequent uplink transmission burst.

19. A method for uplink data reception performed by a base station BS, comprising: transmitting a first signaling to a user equipment UE indicating the existence of a first channel access priority class value in a second signaling, wherein the first channel access priority class value is used by the BS to initiate a channel occupancy; transmitting the second signaling to the UE, which indicates the first channel access priority class value and schedules a physical uplink shared channel PUSCH for transmitting uplink data; and receiving the uplink data from the UE on the PUSCH.

20. The method according to claim 19, further comprising: transmitting the offset between a downlink transmission burst within the channel occupancy and a subsequent uplink transmission burst to the UE.

21. The method according to claim 20, wherein the offset is indicated by a number of time slots or a number of symbols in downlink control information DCI.

22. The method according to claim 20, wherein the offset is indicated from a set of predefined states in downlink control information DCI.

23. The method according to claim 20, wherein the offset is indicated in the first signaling.

24. The method according to claim 20, wherein the offset is indicated in the second signaling.

25. The method according to claim 19, wherein the first signaling is indicated in common physical downlink control information PDCCH.

26. The method according to claim 19, wherein the existence of the first channel access priority class value in the second signaling is configured by RRC signaling.

27. The method according to claim 19, wherein the existence of the first channel access priority class value in the second signaling is determined by whether uplink transmission within the channel occupancy is allowed.

28. The method according to claim 19, wherein the second signaling further indicates whether the scheduled PUSCH is within or outside the channel occupancy.

29. The method according to claim 19, wherein the second signaling further indicates whether the channel access procedure performed by the UE is a type 1 channel access procedure with a random backoff counter generated within a window.

30. The method according to claim 29, wherein in response to the second signaling further indicating that the channel access procedure is the type 1 channel access procedure, the second signaling further indicates the first channel access priority class value.

31. The method according to claim 29, wherein in response to the second signaling further indicating that the channel access procedure is not the type 1 channel access procedure, the second signaling further indicates an offset between a downlink transmission burst and a subsequent uplink transmission burst within the channel occupancy.

32. An apparatus, comprising: a non-transitory computer-readable medium having computer-executable instructions stored thereon; a receiving circuitry; a transmitting circuitry; and a processor coupled to the non-transitory computer-readable medium, the receiving circuitry, and the transmitting circuitry, wherein the computer-executable instructions cause the processor to implement the method of any one of claims 1 to 18.

33. An apparatus, comprising: a non-transitory computer-readable medium having computer-executable instructions stored thereon; a receiving circuitry; a transmitting circuitry; and a processor coupled to the non-transitory computer-readable medium, the receiving circuitry, and the transmitting circuitry, wherein the computer-executable instructions cause the processor to implement the method of any one of claims 19 to 31.

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