Listen-before-talk random access device and method using adaptive energy detection threshold selection

Abstract

A listen-before-talk random access method using adaptive energy detection threshold selection is performed by a device. A plurality of component units, such as code block groups (CBGs), in a transport block are determined to be retransmitted via a contention-based random access operation. An energy detection threshold (EDT) based on the component unit is selected. The EDT is associated with the determined component units to be retransmitted. Energy detection is performed in an initial contention-based random access operation using the selected component unit-based EDT.

Description

Technical Field

[0001] The present disclosure relates to the field of communication systems, and more particularly, to a listen-before-talk random access device and method using adaptive energy detection threshold selection. Background Art

[0002] Due to the scarcity of licensed spectrum compared to the growing demand for spectrum, stakeholders in the cellular telecommunication business have started using unlicensed bands to collaborate with licensed band networks.

[0003] Technical issues

[0004] When transmitting data over unlicensed bands, transmission reliability and efficiency become important issues. A major issue in unlicensed band communications is the temporally unpredictable transmission opportunities in the listen-before-talk (LBT) mechanism. A transmitter performing listen-before-talk (LBT) may suffer from a data transmission backoff time before accessing the unlicensed channel. In addition, the more user equipment (UE) devices compete for access to the unlicensed band, the greater the possibility of LBT failure. Unpredictable transmission opportunities may delay the data transmission, which makes communications in unlicensed spectrum more challenging, especially for low-latency communication scenarios. The so-called hidden node problem and burst interference pose additional challenges.

[0005] A transmitter may need to perform energy detection to determine if an unlicensed band is already occupied by another transmitter. Basically, energy detection is performed by comparing the radio energy level in the target band to a predefined threshold. A transmitter may have to listen for a long time before accessing the unlicensed spectrum.

[0006] The present disclosure proposes a method and apparatus for solving the transmission delay problem in unlicensed frequency bands.

[0007] Technical Solution

[0008] The purpose of the present disclosure is to propose a listen-before-talk random access device and method using adaptive energy detection threshold selection.

[0009] In a first aspect of the present disclosure, a listen-before-talk random access method using adaptive energy detection threshold selection is performed by a device. A plurality of component units, such as code block groups (CBGs), to be retransmitted in a transport block through a contention-based random access operation are determined. An energy detection threshold (EDT) based on the component unit is selected. The EDT is associated with the determined component units to be retransmitted. Energy detection is performed in an initial contention-based random access operation using the selected component unit-based EDT.

[0010] In a second aspect of the present disclosure, a device includes a transceiver and a processor. The processor is connected to the transceiver and configured to perform the following steps, including: determining a plurality of component units in a transmission block to be retransmitted through a contention-based random access operation; selecting a component unit-based energy detection threshold (EDT), the component unit-based EDT being associated with the determined component units to be retransmitted; and performing energy detection in an initial contention-based random access operation using the selected component unit-based EDT.

[0011] The disclosed method can be executed in a chip. The chip includes a processor configured to call and run a computer program stored in a memory so that a device equipped with the chip executes the disclosed method.

[0012] The disclosed method can be programmed as computer-executable instructions stored in a non-transitory computer-readable medium. When the non-transitory computer-readable medium is loaded into a computer, it instructs the processor of the computer to execute the disclosed method.

[0013] The non-transitory computer-readable medium may include at least one of the following groups: a hard disk, a read-only compact disk drive (CD-ROM), an optical storage device, a magnetic storage device, a read-only memory (Read Only Memory), a programmable read-only memory (Programmable Read Only Memory), an erasable programmable read-only memory (ErasableProgrammable Read Only Memory), an electrically erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (ElectricallyErasableProgrammable Read Only Memory) and a flash memory.

[0014] The disclosed method can be programmed as a computer program product, which causes a computer to execute the disclosed method.

[0015] The disclosed method can be programmed into a computer program, which enables a computer to execute the disclosed method.

[0016] Beneficial Effects

[0017] The current LBT mechanism designed for TB-level transmission involves an energy detection threshold (EDT) for TB-level transmission. This threshold may be unreasonable, especially when the transmitter transmits only a small amount of load, such as a code block group (CBG), in an unlicensed channel. This threshold may lead to continuous access attempts, which may seriously delay data transmission. The present disclosure provides a listen-before-talk access method using adaptive energy detection threshold selection to solve the existing delay problem in the LBT mechanism. The disclosed method can be applied to the listen-before-talk (LBT) mechanism in the New Radio based unlicensed (NR-U) spectrum.

[0018] For LBT initiated by user equipment (UE), the large load of retransmitted TBs may cause LBT failure. According to the disclosed method, a series of CBG-based EDTs are determined by adjusting the predefined EDT with an offset value and used for energy detection to transmit a portion of the TB. Some CBG-based EDTs can be selected to adapt to different scenarios. Thereby, flexibility and efficiency in contention-based unlicensed band access are improved. In addition, it is proposed to configure a series of CBG-based EDTs through RRC signaling and control information of gNB. The disclosed method improves LBT efficiency in NR-U.

[0019] For LBT initiated by the base station, after determining the CBG to be retransmitted, the base station selects a series of CBG-based EDTs of the predefined EDT. Alternatively, a series of CBG-based EDTs are configured through RRC signaling. The base station determines and generates a new CBGTI based on the CBG, which is used to determine the EDT. The base station can use the determined EDT to perform a successful LBT. The UE detects and receives the CBG based on the generated CBGTI. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments or related technologies of the present disclosure, the following drawings to be described in the embodiments are briefly introduced. Obviously, the drawings are only some embodiments of the present invention, and ordinary technicians in this field can obtain other drawings based on these drawings.

[0021] Figure 1 is a block diagram of a user equipment (UE) and a base station (BS) according to an embodiment of the present disclosure.

[0022] Figure 2 is a schematic diagram illustrating an embodiment of the disclosed method applied to uplink retransmission.

[0023] Figure 3is a schematic diagram showing a series of energy detection thresholds (EDT).

[0024] Figure 4 is a flow chart illustrating a listen-before-talk random access method using adaptive energy detection threshold selection according to an embodiment of the present disclosure.

[0025] Figure 5 is a flowchart illustrating a listen-before-talk random access method using adaptive energy detection threshold selection according to another embodiment of the present disclosure.

[0026] Figure 6 is a flowchart illustrating a listen-before-talk random access method using adaptive energy detection threshold selection according to yet another embodiment of the present disclosure.

[0027] Figure 7 is a schematic diagram illustrating an embodiment of the disclosed method applied to downlink retransmission.

[0028] Figure 8 is a block diagram of a wireless communication system according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0029] The technical problems, structural features, objectives and effects of the embodiments of the present disclosure are described in detail below in conjunction with the accompanying drawings. Specifically, the terms in the embodiments of the present disclosure are only used to illustrate the purpose of a certain embodiment of the present disclosure and are not used to limit the present disclosure.

[0030] Figure 1 It is shown that, in some embodiments, a user equipment (UE) 10 and a base station (BS) 20 for performing a listen-before-talk random access method using adaptive energy detection threshold selection according to an embodiment of the present disclosure are provided. The UE 10 may include a processor 11, a memory 12, and a transceiver 13. Examples of the base station 20 may include an eNB or a gNB. The base station 20 may include a processor 21, a memory 22, and a transceiver 23. The processor 11 or 21 may be configured to implement the functions, processes, and / or methods described herein. The layers of the wireless interface protocol may be implemented in the processor 11 or 21. The memory 12 or 22 is operably coupled to the processor 11 or 21 and stores various information to operate the processor 11 or 21. The transceiver 13 or 23 is operably coupled to the processor 11 or 21, and the transceiver 13 or 23 transmits and / or receives a radio signal 13 through a wireless channel 110.

[0031] The processor 11 or 21 may include an application-specific integrated circuit (ASIC), other chipsets, logic circuits and / or data processing devices. The memory 12 or 22 may include a read-only memory (ROM), a random access memory (RAM), flash memory, a memory card, a storage medium and / or other storage devices. The transceiver 13 or 23 may include a baseband circuit and a radio frequency (RF) circuit to process radio frequency signals. When the embodiments of the present invention are implemented in software, the techniques described herein may be implemented using modules (e.g., procedures, functions, executable programs, etc.) that perform the functions described herein. These modules may be stored in the memory 12 or 22 and executed by the processor 11 or 21. The memory 12 or 22 may be implemented within the processor 11 or 21, or implemented outside the processor 11 or 21, in which case these may be communicatively coupled to the processor 11 or 21 via an interface.

[0032] BS20 may be connected to a network entity device as a node in a core network (CN). CN may include an LTE CN or a 5GC, and 5GC includes a user plane function (UPF), a session management function (SMF), a mobility management function (AMF), a unified data management (UDM), a policy control function (PCF), a control plane (CP) / user plane (UP) separation (CUPS), an authentication server (AUSF), a network slice selection function (NSSF), and a network exposure function (NEF).

[0033] In some embodiments, a processor (e.g., processor 11 or 21) is configured to perform a listen-before-talk random access method using adaptive energy detection threshold selection. A plurality of component units, e.g., code block groups (CBGs), to be retransmitted in a transport block through a contention-based random access operation are determined. An energy detection threshold (EDT) based on the component unit is selected. The EDT is associated with the determined component unit to be retransmitted. Energy detection is performed in an initial contention-based random access operation using the selected component unit-based EDT.

[0034] The present disclosure provides two types of LBT mechanisms, including UE-initiated LBT and BS-initiated LBT. For UE-initiated LBT, for example, UE 10 selects a suitable EDT relative to the CBG indication in the code block group transmission information (CBGTI) indicated by the BS (e.g., BS20), selects and retransmits the CBG. For BS-initiated LBT, after determining the retransmitted CBG, the BS (e.g., BS20) selects the optimal energy detection threshold, and then generates the CBGTI based on the CBG to be retransmitted.

[0035] Embodiments of the disclosed method involving UE-initiated LBT and physical uplink shared channel (PUSCH) CBGTI determination are described in detail below.

[0036] CBG-based transmission has been adopted by 3GPP RAN1 in Rel-15, which includes CBG-based physical downlink shared channel (PDSCH) transmission and CBG-based physical uplink shared channel (PUSCH) transmission. If the UE configures CBG-based transmission, the UE determines the number of CBGs used for the transport block (TB).

[0037] For CBG-based transmissions, the CBGTI field in the scheduling downlink control information (DCI) indicates which CBGs of the TB are present in the new transmission or retransmission of the TB. The length of the CBGTI field is N TB N bits (bit), where N TB is the number of TB, and N is the number of CBGs in a TB. TB=2, the CBGTI field bits are mapped so that the first group of N bits starting from the most significant bit (MSB) corresponds to the first TB, and the second group of N bits corresponds to the second TB. The first M bits of each group of N bits in the CBGTI field of a TB have an ordered one-to-one mapping with the M CBGs in the TB, where the MSB is mapped to CBG#0, i.e., the first CBG in the TB.

[0038] For the retransmission of a TB indicated by a new data indicator (NDI), the CBGTI is used to indicate which CBGs in the TB are present in the retransmission. Specifically, a bit value of "0" in the CBGTI field mapped to a CBG indicates that the corresponding CBG is not transmitted in the retransmission. A bit value of "1" mapped to a CBG indicates that the CBG is transmitted in the retransmission.

[0039] When the BS transmits UL DCI 0_1 to modulate a single PUSCH, the CBGTI field is present in the modulated DCI. If the UE is configured to transmit CBG-based transmissions, the UE determines the number of CBGs used for PUSCH transmission. After receiving the uplink data in the PUSCH transmission, the BS generates respective hybrid automatic repeat request-acknowledgement (HARQ-ACK) information bits for the CBGs in the TB reception, and then places the HARQ-ACK bits according to the CBG ID. If the BS does not correctly detect the TB, the BS generates a CBGTI in the DCI 0_1 format and sends it to the UE. Therefore, a bit value of "1" in the CBGTI associated with the CBG indicates that the associated CBG needs to be retransmitted.

[0040] Energy detection threshold based on CBG:

[0041] The CBG-based energy detection threshold (EDT) is described in detail below. A transmitter, such as UE 10 or BS 20, selects a component unit-based EDT associated with a component unit (eg, CBG) determined to be retransmitted in a transport block.

[0042] like Figure 2 As shown, if BS 20 transmits DCI to indicate that UE 10 will perform retransmission, UE 10 performs LBT to access the unlicensed channel to retransmit data, for example, Figure 2 If the channel is occupied by other transmitters (e.g., another UE), and BS 20 directly uses the predefined EDT for energy detection as usual, UE 10 may face LBT failure due to the large load of retransmission TBs, e.g. Figure 2 According to an embodiment of the disclosed method, BS 20 may perform LBT using EDT at the CBG level to acquire a channel and retransmit corresponding CBGs, for example, the second and third CBGs in PUSCH #2.

[0043] like Figure 3 As shown, a series of CBG-based EDTs are proposed. A transmitter, such as UE 10 or BS 20, can select one of the multiple CBG-based EDTs to perform energy detection in the LBT process. The first CBG-based EDT corresponds to an EDT with N1 CBGs for the LBT process, where N1=1, 2, 3…N, and N is the maximum number of CBGs in a TB. The second CBG-based EDT corresponds to an EDT with N2 CBGs for the LBT process, where N2 is an integer and N≥N2≥N 1。 Furthermore, the last CBG-based EDT corresponds to the EDT with N CBGs for the LBT procedure.

[0044] For CBG-based EDT determination, three embodiments are proposed, and any combination of these three examples may lead to new implementations.

[0045] Example 1 - UE implementation:

[0046] The CBG-based EDT can be inherently generated by the UE 10. The UE 10 sets a series of actual EDTs to be greater than or equal to a predefined EDT, which is predetermined by configurations such as high-level parameters, BS output power, and / or allocated bandwidth. After the predefined EDT is determined, the actual EDT is set by adjusting the predefined EDT according to an offset value signaled by one or more high-level parameters. The UE 10 obtains a series of CBG-based EDTs to accommodate the transmission of different data loads. Examples of CBG-based EDTs include a first CBG-based EDT, a second CBG-based EDT, ... and a last CBG-based EDT.

[0047] like Figure 3 As shown, the predefined TB-level EDT for energy detection on an unlicensed channel occupied by another transmitter may easily lead to LBT failure at the UE 10. On the other hand, the CBG-level EDT can help the UE 10 to successfully perform LBT and then retransmit the corresponding CBG.

[0048] Example 2 - RRC configuration:

[0049] To simplify UE implementation, a series of CBG-based EDTs may be configured through radio resource control (RRC) signaling, such as a first CBG-based EDT, a second CBG-based EDT, ... and a final CBG-based EDT. UE 10 may receive RRC signaling and directly use these EDTs for energy detection carried in the RRC signaling without additional threshold calculation.

[0050] Example 3 - BS Indication:

[0051] BS 20 determines a series of CBG-based EDTs relative to configurations such as high-level parameters, BS output power, and / or bandwidth used, and sends the series of CBG-based EDTs to UE 10 via PDCCH or PDSCH. The series of CBG-based EDTs includes a first CBG-based EDT, a second CBG-based EDT, and a final CBG-based EDT. UE 10 may receive a control signal in PDCCH or PDSCH and directly use these EDTs for energy detection carried in PDCCH or PDSCH without additional threshold calculation. The control signal may include DCI or a media access control element (MAC control element, MACCE).

[0052] CBG selection method:

[0053] If a PUSCH transport block, such as PUSCH#2, is not received and decoded, BS 20 sets the corresponding CBGTI and then sends the CBGTI to UE 10 via DCI. UE 10 receives DCI instructing UE 10 to retransmit M CBGs. UE 10 may select one or more CBGs for retransmission. The purpose of selecting CBGs is to retransmit as many CBGs as possible.

[0054] like Figure 2 As shown, several embodiments of CBG selection are proposed to retransmit as many CBGs as possible. Option 1-Option 4 represent embodiments 1 to 4 of data transmission.

[0055] Option 1:

[0056] As the current retransmission scheme, optional embodiment 1 uses predefined TB-level EDT to perform energy detection in LBT operation. When a transmission opportunity is obtained through a successful LBT operation, UE 10 directly retransmits the entire TB, for example, PUSCH#2, to BS 20.

[0057] Option 2:

[0058] refer to Figure 4, a transmitter, such as UE 10, determines one or more CBGs to be retransmitted in a transport block (TB) (block 242). In order to transmit all CBGs as quickly as possible, UE 10 transmits only M CBGs of the determined CBGs to be retransmitted to the BS, where M is the number of all retransmitted CBGs, e.g. Figure 2 CBG#2 and CBG#3 in PUSCH 2 are shown.

[0059] The transmitter determines the number of the one or more CBGs to be retransmitted (block 244), selects a CBG-based energy detection threshold (EDT), the CBG-based EDT is associated with the number of the one or more CBGs to be retransmitted (block 246), and uses the selected CBG-based EDT to perform energy detection in a listen-before-talk (LBT) operation (block 248). The UE 10 uses a CBG-based EDT, such as a second CBG-based EDT, to perform energy detection in the LBT operation, the CBG-based EDT being associated with the corresponding number of CBGs. Figure 2 In the example of , UE 10 uses a second CBG-based EDT associated with two CBGs (i.e., CBG#2 and CBG#3) for energy detection in LBT operation. Using CBG-based EDT can greatly reduce latency. When a transmission opportunity is obtained through a successful LBT operation, UE 10 transmits all M CBGs.

[0060] Option 3:

[0061] refer to Figure 5 , a transmitter, such as UE 10, determines one or more CBGs to be retransmitted in a transport block (TB) (block 250). The transmitter determines a reduced number of one or more CBGs to be retransmitted (block 251). The reduced number of one or more CBGs forms a first subset of CBGs in the TB.

[0062] If the LBT using the EDT proposed in the optional embodiment 2 fails, another EDT based on a smaller number of CBGs may be used to perform energy detection in the LBT operation. If the LBT using the EDT proposed in the optional embodiment 2 fails, the UE 10 selects a reduced number of CBGs for retransmission starting from the first indicated CBG, e.g. Figure 2 CBG#2 shown.

[0063] The transmitter selects a CBG-based EDT associated with a reduced number of one or more CBGs to be retransmitted (block 252), and uses the selected CBG-based EDT to perform energy detection in an LBT operation (block 253). In particular, the CBG-based EDT associated with (M-1) CBGs is used for energy detection in a first LBT attempt. The (M-1) CBGs form a first subset CBG in a TB. The UE 10 determines whether the LBT attempt is successful (block 254). If the first LBT attempt is successful, the UE 10 retransmits the first (M-1) CBG to the BS 20 (block 255). If the first LBT attempt fails, the number of CBGs is reduced by one to obtain (M-2) in the first repetition of block 251. The UE 10 uses the CBG-based EDT associated with the (M-2) CBGs for energy detection in a second LBT attempt. The (M-2) CBGs form a second subset CBG in a TB. If the second LBT attempt is successful, UE 10 retransmits the first (M-2) CBGs to BS 20. If the second LBT attempt fails, UE 10 continues a similar process until the number of CBGs is reduced to one or the LBT succeeds. In optional embodiment 3, UE 10 retransmits the first few CBGs by default, and uses a CBG-based EDT associated with the number of CBGs to be retransmitted in the LBT attempt to gradually reduce the number of CBGs for retransmission. Since this rule is predefined by BS 20 and UE 10, UE 10 does not need to indicate the CBG ID of the retransmitted CBG to BS 20. For example, Figure 2 As shown, in a successful LBT using the first CBG-based EDT, UE 10 retransmits CBG#2 to BS 20.

[0064] Option 4:

[0065] Similar to Alternative Embodiment 3, another EDT based on a smaller number of CBGs may be used for energy detection in LBT operation. If LBT using the EDT proposed in Alternative Embodiment 2 fails, the UE 10 selects a reduced number of CBGs, e.g. Figure 2CBG#2 and CBG#3 shown, the reduced number of CBGs are arbitrarily selected from the CBGs indicated for retransmission. Specifically, the CBG-based EDT associated with the selected (M-1) CBGs is used for energy detection in the first LBT attempt. The (M-1) CBGs form a first subset of CBGs in the TB. If the first LBT attempt is successful, the UE 10 retransmits the selected (M-1) CBGs to BS20. If the first LBT attempt fails, the number of CBGs is reduced by one to obtain (M-2). The UE 10 selects (M-2) CBGs from the CBGs indicated for retransmission, and uses the CBG-based EDT associated with the (M-2) CBGs for energy detection in the second LBT attempt. The (M-2) CBGs form a second subset of CBGs in the TB. If the second LBT attempt is successful, the UE 10 retransmits the selected (M-2) CBGs to BS20. If the second LBT attempt fails, the UE 10 continues a similar process until the number of CBGs is reduced to one or the LBT is successful. In optional embodiment 4, UE 10 retransmits the selected CBG and gradually reduces the number of CBGs for retransmission using CBG-based EDT associated with the number of CBGs selected to be retransmitted in the LBT attempt. Since the selected CBG is not preset by BS 20 and UE 10, UE 10 does not need to indicate the CBG ID of the retransmitted CBG to BS 20.

[0066] The first subset CBG is explicitly indicated by CBG transmission information (CBGTI) in the downlink information (DCI), which is used to schedule the physical uplink shared channel (PUSCH), which can be accessed through a listen-before-talk operation initiated by the user equipment. Alternatively, the first subset CBG can be implicitly indicated between the BS and the UE.

[0067] In optional embodiment 4, UE 10 retransmits the selected one or more CBGs at the cost of additional overhead of CBG ID related signaling. Figure 2 As shown, UE 10 selects and transmits a CBG having a CBG ID of CBG#3.

[0068] Even if a small number of CBGs or only one CBG is successfully retransmitted, the UE 10 adds the CBG to the HARQ buffer of the corresponding TB, e.g. Figure 2 This increases the possibility of successful TB detection.

[0069] An embodiment of the disclosed method involving LBT initiated by gNB is described in detail below. BS20 can determine one or more CBGs to be retransmitted.

[0070] UE 10 capable of CBG-based transmission and reception may receive a first PDSCH TB modulated by DCI format 1_1, which includes a CBG for the TB. UE 10 generates corresponding HARQ-ACK information bits for the CBG for the TB, and then places the HARQ-ACK bits according to the CBG ID of the CBG. If UE 10 receives more subsequent PDSCH TBs, UE 10 connects the HARQ-ACK information bits for the CBGs of the subsequent PDSCH TBs after the first PDSCH TB. UE 10 sends the HARQ-ACK bits to BS 20, and BS 20 may receive the HARQ-ACK bits and determine one or more CBGs to be retransmitted based on the HARQ-ACK bits.

[0071] BS20 may use a CBG-based energy detection threshold.

[0072] In order to retransmit the one or more CBGs, BS20 may use one of the CBG-based EDTs to perform energy detection in the LBT operation. If the HARQ-ACK codebook reported by UE 10 indicates that UE 10 has not successfully detected at least one TB, such as PDSCH#2, BS 20 performs LBT to access an unlicensed channel to send at least one TB, such as PDSCH#2. In order to complete the retransmission as soon as possible, BS20 may use a CBG-based EDT to attempt LBT. BS20 selects one of the multiple CBG-based EDTs, so that the smaller the CBG load transmitted by BS20, the higher the probability that BS20 attempts to access the channel through LBT. In order to reduce the load, BS20 divides the TBs to be retransmitted into CBGs according to the CBG-based HARQ-ACK codebook.

[0073] For CBG-based EDT determination, two methods are proposed, and any combination of these two methods may lead to new methods.

[0074] Method 1 - EDT provided by BS

[0075] BS20 determines a predefined EDT that is preset relative to a configuration including, for example, high-level parameters, BS20 output power, and / or bandwidth used. BS20 also proposes to select a series of CBG-based EDTs that are higher than the predefined EDT to support CBG-based energy detection. The series of CBG-based EDTs may include a first CBG-based EDT, a second CBG-based EDT, ..., and a last CBG-based EDT. Specifically, BS20 may generate a CBG-based EDT.

[0076] Method 1 - EDT provided by RRC configuration

[0077] In order to simplify BS implementation, it is proposed to configure a series of CBG-based EDTs through RRC signaling. Specifically, BS20 can generate CBG-based EDTs according to RRC signaling.

[0078] CBG selection and CBGTI determination are described in detail below.

[0079] Similar to the CBG selection method proposed in the description of UE-initiated LBT, BS20 selects as many CBGs as possible to reduce the retransmission time. BS20 records the CBGs to be retransmitted and generates the CBGTIB bit field in the DCI 1_1 format to indicate the CBGs to be retransmitted. Compared with the existing CBGTI design, BS20 can select only a part of the CBGs to be retransmitted.

[0080] refer to Figure 6 , the transmitter, such as BS20, determines one or more CBGs to be retransmitted in the TB (block 260). The transmitter determines the reduced number of one or more CBGs to be retransmitted (block 261). For example, BS20 may select only (M-1) CBGs from the M CBGs to be retransmitted, and select the CBG-based EDT associated with the (M-1) CBGs for energy detection.

[0081] The transmitter selects a CBG-based EDT associated with a reduced number of one or more CBGs to be retransmitted (block 262), and uses the selected CBG-based EDT to perform energy detection in the LBT operation (block 263). BS20 uses the selected CBG-based EDT to perform energy detection in the LBT attempt. Specifically, the CBG-based EDT associated with the selected (M-1) CBGs is used for energy detection in the first LBT attempt. The (M-1) CBGs form a first subset CBGs in the TB. BS20 determines whether the LBT attempt is successful (block 264). If the first LBT attempt is successful, BS20 retransmits the selected (M-1) CBGs to UE 10 (block 265). If the first LBT attempt fails, the number of CBGs is reduced by one to obtain (M-2) in the first repetition of block 261. BS20 selects (M-2) CBGs from the CBGs indicated for retransmission, and uses the CBG-based EDT associated with the (M-2) CBGs for energy detection in the second LBT attempt. The (M-2) CBGs form a second subset of CBGs in the TB. If the second LBT attempt is successful, BS20 retransmits the selected (M-2) CBGs to UE 10. If the second LBT attempt fails, BS20 continues a similar process until the number of CBGs is reduced to one or the LBT succeeds.

[0082] If the UE 10 successfully detects the CBGs according to the CBGTI, the UE 10 adds these CBGs to the corresponding TB HARQ buffer and receives other retransmitted CBGs until the retransmission of the CBGs is completed.

[0083] like Figure 7 As shown, when optional embodiment 3 is adopted instead of optional embodiment 2, if LBT is successful, the CBGTI value is '0100' instead of '0110', thereby instructing BS 20 to retransmit CBG#2 from CBG#2 and CBG#3. After successfully detecting CBG#2, UE 10 puts CBG#2 into the PDSCH#2 buffer to facilitate the successful detection of the TB PDSCH#2.

[0084] Figure 8 is a block diagram of an example system 700 for wireless communications according to an embodiment of the present disclosure. The embodiments described herein may be implemented into a system using any suitably configured hardware and / or software. Figure 8 The system 700 is illustrated to include a radio frequency (RF) circuit 710, a baseband circuit 720, a processing unit 730, a memory / storage 740, a display 750, a camera 760, a sensor 770, and an input / output (I / O) interface 780 that are coupled to each other as shown.

[0085] The processing unit 730 may include circuits such as, but not limited to, one or more single-core or multi-core processors. The processor may include any combination of general-purpose processors and special-purpose processors, such as a graphics processor, an application processor. The processor may be coupled to the memory / storage and configured to execute instructions stored in the memory / storage to enable various applications and / or operating systems to run on the system.

[0086] The baseband circuit 720 may include circuits such as, but not limited to, one or more single-core or multi-core processors. The processor may include a baseband processor. The baseband circuit may handle various radio control functions so that it communicates with one or more radio networks through a radio frequency circuit. The radio control functions may include, but are not limited to, signal modulation, encoding, decoding, radio frequency transfer, etc. In some embodiments, the baseband circuit may provide communications compatible with one or more radio technologies. For example, in some embodiments, the baseband circuit may support the fifth generation mobile communication technology new air interface (5th Generation Mobile Communication Technology New Radio, 5G NR), long term evolution (Long Term Evolution, LTE), and the evolved universal terrestrial radio access network (Evolved Universal Terrestrial Radio Access Network, EUTRAN) and / or other wireless metropolitan area networks (Wireless Metropolitan Area Network, WMAN), wireless local area network (Wireless Local Area Network, WLAN), wireless personal area network (Wireless Personal Area Network, WPAN). An embodiment in which the baseband circuit is configured to support radio communications of more than one wireless protocol may be referred to as a multi-mode baseband circuit. In various embodiments, the baseband circuitry 720 may include circuitry for operating on signals that are not strictly considered to be baseband frequencies. For example, in some implementations, the baseband circuitry may include circuitry for operating on signals having intermediate frequencies that are between baseband frequencies and radio frequencies.

[0087] The RF circuit 710 can implement communication with a wireless network using modulated electromagnetic radiation through a non-solid medium. In various embodiments, the RF circuit can include switches, filters, amplifiers, etc. to facilitate communication with the wireless network. In various embodiments, the RF circuit 710 can include circuits for operating signals that are not strictly considered to be at radio frequencies. For example, in some embodiments, the RF circuit can include circuits for operating signals having an intermediate frequency, the intermediate frequency being between the baseband frequency and the radio frequency.

[0088] In various embodiments, the transmitter circuit, control circuit or receiver circuit discussed above regarding the UE, eNB or gNB may be included in whole or in part in one or more circuits in the radio frequency circuit, baseband circuit and / or processing unit. As used herein, "circuit" may refer to, be part of or include an application specific integrated circuit (ASIC), an electronic circuit, a processor (shared, dedicated or group) and / or a memory (shared, dedicated or group) that executes one or more software or firmware programs, a combinational logic circuit and / or other suitable hardware components that provide the functionality. In some embodiments, the electronic device circuit may be implemented in one or more software or firmware modules, or the functions associated with the circuit may be implemented by one or more software or firmware modules. In some embodiments, the baseband circuit, processing unit and / or some or all of the components of the memory / storage may be implemented together on a system on a chip (System On A Chip, SOC).

[0089] The memory / storage 740 can be used for loading and storing data and / or instructions, for example, for the system. The memory / storage for an embodiment can include any combination of suitable volatile memory, such as dynamic random access memory (DRAM), and / or non-volatile memory, such as flash memory. In various embodiments, the I / O interface 780 can include one or more user interfaces intended to enable a user to interact with the system and / or a peripheral component interface intended to enable a peripheral component to interact with the system. The user interface can include, but is not limited to, a physical keyboard or keypad, a touch pad, a speaker, a microphone, etc. The peripheral component interface can include, but is not limited to, a non-volatile memory port, a universal serial bus (USB) port, an audio jack, and a power interface.

[0090] In various embodiments, the sensor 770 may include one or more sensing devices to determine environmental conditions and / or location information associated with the system. In some embodiments, the sensor may include, but is not limited to, a gyroscope sensor, an accelerometer, a proximity sensor, an ambient light sensor, and a positioning unit. The positioning unit may also be part of a baseband circuit and / or an RF circuit, or interact with it to communicate with components of a positioning network, such as a global positioning system (GPS) satellite. In various embodiments, the display 750 may include a display, such as a liquid crystal display and a touch screen display. In various embodiments, the system 700 may be a mobile computing device, such as, but not limited to, a laptop computing device, a tablet computing device, a netbook, an ultrabook, a smart phone, etc. In various embodiments, the system may have more or fewer components, and / or different architectures. Where appropriate, the methods described herein may be implemented as a computer program. The computer program may be stored on a storage medium, such as a non-temporary storage medium.

[0091] Some of the disclosed embodiments are combinations of techniques / processes that may be employed in 3GPP specifications to create a final product.

[0092] It is understood by a person with ordinary skills in the art that each unit, algorithm and step described and disclosed in the embodiments of the present disclosure is implemented using electronic hardware or a software combination of a computer and electronic hardware. Whether these functions are run in hardware or in software depends on the application conditions and design requirements of the technical solution. A person of ordinary skill in the art can use different ways to implement the functions of each specific application, and such implementation should not exceed the scope of the present disclosure. A person of ordinary skill in the art can understand that since the working processes of the above-mentioned systems, devices and units are basically the same, reference can be made to the working processes of the systems, devices and units in the above-mentioned embodiments. For ease of description and simplification, these working processes will not be described in detail.

[0093] It is to be understood that the systems, devices and methods disclosed in the embodiments of the present invention may be implemented in other ways. The embodiments are merely illustrative. The division of the units mentioned is only based on the division of logical functions, and other division methods may be used in implementation. It is possible that multiple units or elements are combined or integrated into another system. It is also possible that some features are omitted or skipped. On the other hand, the mutual coupling, direct coupling or communication coupling described or discussed above is achieved through some ports, devices or units, whether indirectly or through electronic, mechanical or other types of communication.

[0094] For the above-mentioned units, the separated elements used for explanation may be physically separated or not physically separated elements. For the above-mentioned units, they may be physical units or not physical units, that is to say, they may be arranged in one place or distributed on multiple network elements. Some or all of the units may be used according to the purpose of the embodiment. In addition, each functional unit in each embodiment may be integrated into a processing unit, or physically independent, or integrated into a processing unit with two or more units.

[0095] If the software functional unit is implemented and used and sold as a product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution proposed in the present disclosure can be basically or partially implemented in the form of a software product. In other words, a part of the technical solution that is beneficial to traditional technology can be implemented in the form of a software product. The software product in the computer is stored in a storage medium, including multiple commands for a computing device (such as a personal computer, a server, or a network device) to run all or part of the steps disclosed in the embodiments of the present disclosure. The storage medium includes a USB disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a floppy disk, or other types of media capable of storing program code.

[0096] The disclosed method provides flexible QoS management based on sidelink traffic type. According to the present disclosure, sidelink transmission of each traffic type can have a configurable priority to meet different communication situations and QoS requirements.

[0097] While the present disclosure has been described in connection with what are considered to be the most practical and preferred embodiments, it is to be understood that the disclosure is not limited to the disclosed embodiments but is intended to cover various arrangements made within the broadest interpretation of the appended claims.

Claims

1. A listen-before-talk random access method using adaptive energy detection threshold selection, which can be performed by a device, comprising: determining a plurality of component units in a transport block to be retransmitted via a contention-based random access operation; selecting a component unit-based energy detection threshold (EDT), the component unit-based EDT being associated with the determined component unit to be retransmitted, wherein each component unit of the plurality of component units in the transport block comprises a code block group (CBG) in the transport block, and the component unit-based EDT comprises a CBG-based EDT; and performing energy detection in an initial contention-based random access operation using the selected component-based EDT, wherein the contention-based random access operation is a listen-before-talk operation; Determining a first subset CBG to be retransmitted in the transport block, wherein the first subset has a reduced number of CBGs, the reduced number of CBGs being lower than a total number of CBGs to be retransmitted in the transport block; selecting a first CBG-based EDT associated with the reduced number of CBGs in the first subset to be retransmitted; performing the energy detection in a first subsequent contention-based random access operation using the selected first CBG-based EDT, wherein the first CBG-based EDT associated with the reduced number of CBGs in the first subset is selected from at least two CBG-based EDTs, a higher CBG-based EDT of the at least two CBG-based EDTs being associated with a smaller data payload of the CBGs for retransmissions and a lower CBG-based EDT of the at least two CBG-based EDTs being associated with a larger data payload of the CBGs for retransmissions; Determining a second subset CBG to be retransmitted in the transport block, wherein the second subset has a reduced number of CBGs, the reduced number of CBGs being lower than the total number of CBGs to be retransmitted in the first subset; selecting a second CBG-based EDT associated with the reduced number of CBGs in the second subset to be retransmitted; and The energy detection is performed in a first subsequent contention-based random access operation using the selected second CBG-based EDT.

2. The method according to claim 1, wherein: The listen-before-talk operation is used to access the new air interface unlicensed spectrum.

3. The method according to claim 1, wherein: The first subset CBG is explicitly indicated by CBG transmission information CBGTI in downlink information DCI, and the DCI is used to schedule a physical uplink shared channel PUSCH, and the PUSCH can be accessed through a listen-before-talk operation initiated by a user equipment.

4. The method according to claim 1, wherein: The first subset CGB is implicitly configured between the user equipment UE and the base station.

5. The method according to claim 4, wherein: The first subset CBG changes starting from the first CBG to be retransmitted in the transmission block.

6. The method according to claim 1, wherein: The at least two CBG-based EDTs are inherently generated by the device.

7. The method according to claim 1, wherein: The at least two CBG-based EDTs are provided by radio resource control RRC signaling.

8. The method according to claim 1, wherein: The at least two CBG-based EDTs are provided by control signaling in a physical downlink control channel PDCCH.

9. The method according to claim 1, wherein: The at least two CBG-based EDTs are provided by control signaling in the physical downlink shared channel PDSCH.

10. A device comprising: Transceiver; as well as A processor is connected to the transceiver and is configured to perform the following steps, including: determining a plurality of component units in a transport block to be retransmitted by a contention-based random access operation, wherein the contention-based random access operation is a listen-before-talk operation; Selecting a component unit-based energy detection threshold (EDT), wherein the component unit-based EDT is associated with the determined component unit to be retransmitted; and performing energy detection in an initial contention-based random access operation using the selected component unit-based EDT, wherein each component unit of the plurality of component units in the transport block comprises a code block group CBG in the transport block, and the component unit-based EDT comprises a CBG-based EDT; Wherein, the processor is further configured to execute: Determining a first subset CBG to be retransmitted in the transport block, wherein the first subset has a reduced number of CBGs, the reduced number of CBGs being lower than a total number of CBGs to be retransmitted in the transport block; selecting a first CBG-based EDT associated with the reduced number of CBGs in the first subset to be retransmitted; and performing said energy detection in a first subsequent contention-based random access operation using the selected first CBG-based EDT; Wherein, the processor is further configured to execute: determining a second subset CBG of the transport block to be retransmitted, wherein the second subset has a reduced number of CBGs, the reduced number of CBGs being lower than the total number of CBGs in the first subset; selecting a second CBG-based EDT associated with the reduced number of CBGs in the second subset to be retransmitted; and The energy detection is performed in a first subsequent contention-based random access operation using the selected second CBG-based EDT, wherein the first CBG-based EDT associated with the reduced number of CBGs in the first subset is selected from at least two CBG-based EDTs, a higher CBG-based EDT of the at least two CBG-based EDTs being associated with a smaller data load of the CBGs for retransmission, and a lower CBG-based EDT of the at least two CBG-based EDTs being associated with a larger data load of the CBGs for retransmission.

11. The device according to claim 10, wherein: The listen-before-talk operation is used to access the new air interface unlicensed spectrum.

12. The device according to claim 10, wherein: The first subset CBG is explicitly indicated by CBG transmission information CBGTI in downlink information DCI, and the DCI is used to schedule a physical uplink shared channel PUSCH, and the PUSCH can be accessed through a listen-before-talk operation initiated by a user equipment.

13. The apparatus according to claim 10, wherein: The first subset CGB is implicitly configured between the user equipment UE and the base station.

14. The device according to claim 13, wherein: The first subset CBG changes starting from the first CBG to be retransmitted in the transmission block.

15. The apparatus according to claim 10, wherein: The at least two CBG-based EDTs are inherently generated by the device.

16. The apparatus according to claim 10, wherein: The at least two CBG-based EDTs are provided by radio resource control RRC signaling.

17. The apparatus according to claim 10, wherein: The at least two CBG-based EDTs are provided by control signaling in a physical downlink control channel PDCCH.

18. The apparatus according to claim 10, wherein: The at least two CBG-based EDTs are provided by control signaling in the physical downlink shared channel PDSCH.

19. A chip, comprising: A processor is configured to call and run a computer program stored in a memory so that a device equipped with the chip executes any one of the methods of claims 1 to 9.

20. A computer-readable storage medium having a computer program stored therein, wherein: The computer program causes a computer to execute any one of the methods of claims 1 to 9.

21. A computer program product comprising a computer program, wherein: The computer program causes a computer to execute any one of the methods of claims 1 to 9.

22. A computer program, wherein The computer program causes a computer to execute any one of the methods of claims 1 to 9.

Images