WO2021098741A1

WO2021098741A1 - Method for harq-ack transmission in nr-u, network device, and terminal device

Info

Publication number: WO2021098741A1
Application number: PCT/CN2020/129862
Authority: WO
Inventors: Zuomin Wu; Hao Lin
Original assignee: Guangdong Oppo Mobile Telecommunications Corp., Ltd.
Priority date: 2019-11-19
Filing date: 2020-11-18
Publication date: 2021-05-27

Abstract

A method for HARQ-ACK transmission in NR-U, a network device, and a terminal device are provided. The method includes: determining, by a network device, downlink feedback information (DFI) in accordance with an uplink transmission from a terminal device, wherein the DFI is for carrying HARQ-ACK feedback information for the uplink transmission; determining, by the network device, at least two downlink control information (DCI) for carrying the DFI, wherein each of the at least two DCI is for carrying a group of DFI, and the DFI includes: at least two groups of DFI; transmitting, by the network device, the at least two DCI to the terminal device.

Description

METHOD FOR HARQ-ACK TRANSMISSION IN NR-U, NETWORK DEVICE, AND TERMINAL DEVICE

TECHNICAL FIELD

The present disclosure generally relates to mechanisms for Hybrid Automatic Repeat Request acknowledgement (HARQ-ACK) transmission, in particular, to a method for HARQ-ACK transmission in New Radio Unlicensed (NR-U) , a network device, and a terminal device.

BACKGROUND

The unlicensed spectrum is a shared spectrum. The communication equipment in different communication systems can use the unlicensed spectrum as long as it meets the regulatory requirements set by the country or region on the unlicensed spectrum, and does not need to apply for a proprietary spectrum authorization from the government.

In order to allow various communication systems that use unlicensed spectrum for wireless communication to coexist friendly in the spectrum, some countries or regions specify regulatory requirements that must be met to use unlicensed spectrum. For example, the communication device follows the principle of “Listen Before Talk (LBT) ” . That is, the device needs to perform channel sensing before transmitting the signal on the channel. Only when the LBT outcome shows that the channel is idle, the communication device can perform signal transmission; otherwise, the device cannot perform signal transmission. In order to ensure fairness, once a device successfully occupies the channel, the transmission duration cannot exceed the Maximum Channel Occupancy Time (MCOT) .

For configured uplink grant transmission in unlicensed spectrum, user equipment (UE) may transmit PUSCH on a pre-configured uplink resource autonomously, which can avoid two times of LBT (one is for UL grant transmission at gNB side and the other is for PUSCH transmission at UE side) , and hence the access delay of uplink transmission in this case can be reduced.

However, the transmission reliability of configured uplink grant in unlicensed carrier cannot be guaranteed since this carrier may be shared by multiple intra-systems and/or inter-systems. Therefore, unlike configured grant transmission in licensed carrier, gNB should explicitly indicate UE whether the configured grant transmission is successfully received or not, e.g., gNB should transmit the corresponding HARQ-ACK feedbacks to UE. The corresponding HARQ-ACK feedbacks which also called as downlink feedback information (DFI) can be carried in downlink control information (DCI) signals.

The DFI can be used to reflect the reception results of uplink transmission at gNB side. One example is, for transport block based (TB-based) HARQ-ACK feedback, that if gNB correctly detects the transport block, the gNB generates an ACK value for the transport block; otherwise, gNB generates a NACK value for the transport block. Another example is, for code block group based (CBG-based) HARQ-ACK feedback, that the gNB generates an ACK value for the HARQ-ACK information bit of a CBG if the gNB correctly received all code blocks of the CBG and generates a NACK value for the HARQ-ACK information bit of a CBG if the gNB incorrectly received at least one code block of the CBG. If gNB correctly detects each of the N CBGs and does not correctly detect the transport block for the N CBGs, the gNB generates a NACK value for each of the N CBGs.

Although the introduction of DFI is due to configured uplink grant transmission, the DFI can contain HARQ-ACK feedbacks for all the uplink HARQ process numbers (or HARQ process IDs) , which includes both configured uplink grant transmission and scheduled uplink grant transmission. The HARQ-ACK codebook in DFI is determined according to the arranged HARQ process numbers, and the valid HARQ-ACK information within the HARQ-ACK codebook can be used for contention window size adjustment in unlicensed carrier.

In new radio in unlicensed spectrum (NR-U) , for uplink transmission, CBG based transmission is supported for scheduled uplink, and CBG based configured uplink grant may also be supported. To improve the transmission efficiency, CBG-based retransmission can be considered, which may require CBG-based HARQ-ACK feedback.

However, CBG-based HARQ-ACK feedback in DFI may lead to a large HARQ-ACK codebook size, which could be hard to be carried in one DCI.

SUMMARY

Accordingly, the present disclosure is directed to a method for HARQ-ACK transmission in NR-U, a network device, and a terminal device, which may solve the above technical problems.

The embodiment of the disclosure provides a method for HARQ-ACK transmission in NR-U. The method includes: determining, by a network device, downlink feedback information (DFI) in accordance with an uplink transmission from a terminal device, wherein the DFI is for carrying HARQ-ACK feedback information for the uplink transmission; determining, by the network device, at least two downlink control information (DCI) for carrying the DFI, wherein each of the at least two DCI is for carrying a group of DFI, and the DFI includes: at least two groups of DFI; transmitting, by the network device, the at least two DCI to the terminal device.

The embodiment of the disclosure provides a network device including a storage circuit, a transceiver, and a processor. The storage circuit stores a plurality of modules. The processor is coupled with the storage circuit and the transceiver, accessing the modules to executing following steps: determining downlink feedback information, DFI in accordance with an uplink transmission from a terminal device, wherein the DFI is for carrying HARQ-ACK feedback information for the uplink transmission; determining at least two downlink control information, DCI, for carrying the DFI, wherein each of the at least two DCI is for carrying a group of DFI, and the DFI includes: at least two groups of DFI; transmitting the at least two DCI to the terminal device via the transceiver.

The embodiment of the disclosure provides a method for HARQ-ACK transmission in NR-U. The method includes: performing, by a terminal device, an uplink transmission to a network device, wherein the network device determines downlink feedback information (DFI) in accordance with the uplink transmission, and the DFI is for carrying HARQ-ACK feedback information for the uplink transmission; receiving, by the terminal device, at least two downlink control information (DCI) from the network device, wherein the at least two DCI are for carrying the DFI, and each of the at least two DCI is for carrying a group of DFI, and the DFI includes: at least two groups of DFI; retrieving the DFI from the at least two DCI.

The embodiment of the disclosure provides a terminal device including a storage circuit, a transceiver, and a processor. The storage circuit stores a plurality of modules. The processor is coupled with the storage circuit and the transceiver, accessing the modules to executing following steps: perform an uplink transmission to a network device via the transceiver, wherein the network device determines downlink feedback information (DFI) in accordance with the uplink transmission, and the DFI is for carrying HARQ-ACK feedback information for the uplink transmission; receiving at least two downlink control information (DCI) from the network device via the transceiver, wherein the at least two DCI are for carrying the DFI, and each of the at least two DCI is for carrying a group of DFI, and the DFI includes: at least two groups of DFI; retrieving the DFI from the at least two DCI.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a further understanding of the disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the disclosure and, together with the description, serve to explain the principles of the disclosure.

FIG. 1 shows functional diagrams of a network device and a terminal device according to an exemplary embodiment of the disclosure.

FIG. 2 shows a flow chart of the method for HARQ-ACK transmission in NR-U according to an embodiment of the disclosure.

FIG. 3A shows the groups of DFI in DFI according to an embodiment of the disclosure.

FIG. 3B shows the structure of DCI according to an embodiment of the disclosure.

FIG. 3C shows the contents of DCI according to FIG. 3A and FIG. 3B.

FIG. 4 shows a flow chart of the method for HARQ-ACK transmission in NR-U according to an embodiment of the disclosure.

FIG. 5 shows a flow chart of the method for HARQ-ACK transmission in NR-U according to an embodiment of the disclosure.

DETAILED DESCRIPTION

Reference will now be made in detail to the present preferred embodiments of the disclosure, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts.

See FIG. 1, which shows functional diagrams of a network device and a terminal device according to an exemplary embodiment of the disclosure. In various embodiments, the network device 10 may be a base station such as eNB, gNB, or the like, but the disclosure is not limited thereto. In FIG. 1, the network device 10 may include a non-transitory storage circuit 102, a transceiver 104, and a processor 106.

The storage circuit 102 could be any fixed or portable random access memory (RAM) , read-only memory (ROM) , flash memory, hard disk, other similar devices or a combination thereof, which records a plurality of modules that can be executed by the processor 106.

The transceiver 104 may include at least a transmitter circuit, a receiver circuit, an analog-to-digital (A/D) converter, and a digital-to-analog (D/A) converter, low noise amplifier (LNA) , mixer, filter, matching circuit, transmission line, power amplifier (PA) , one or more antenna units and local storage media components to provide wireless transmission functions for the network device 10, but the disclosure is not limited thereto.

The processor 104 is coupled to the storage circuit 102 and the transceiver 104, and may be, for example, a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP) , a plurality of microprocessors, one or more microprocessors in association with a DSP core, a controller, a microcontroller, Application Specific Integrated Circuits (ASICs) , Field Programmable Gate Array (FPGAs) circuits, any other type of integrated circuit (IC) , a state machine, and the like.

In various embodiments, the terminal device 11 may be any type of communication devices or user equipment (UE) , such as smart phones, notebook, tablet computer, or the like. In FIG. 1, the terminal device 11 may include a non-transitory storage circuit 112, a transceiver 114, and a processor 116, and the possible ways to implement the storage circuit 112, the transceiver 114, and the processor 116 may be referred to the descriptions of the storage circuit 102, the transceiver 104, and the processor 106, which would not be repeated herein.

In the embodiments of the disclosure, the processor 106 may access the modules stored in the storage circuit 102 to implement the method for HARQ-ACK transmission in NR-U provided in the disclosure, which would be further discussed in the following.

See FIG. 2, which shows a flow chart of the method for HARQ-ACK transmission in NR-U according to an embodiment of the disclosure. The method of this embodiment may be executed by the network device 10 to transmit DFI to the terminal device 11 in FIG. 1, and the details of each step in FIG. 2 will be described below with the components shown in FIG. 1.

In the embodiment, the terminal device 11 may perform an uplink transmission with respect to the network device 10. For example, the terminal device 11 may transmit a user signal to the terminal device 11 during the uplink transmission, wherein the user signal may be a configured uplink grant or a scheduled uplink grant sent from the terminal device 11 to the network device 10, but the disclosure is not limited thereto.

Accordingly, in step S210, the processor 106 may determine DFI in accordance with the uplink transmission from the terminal device 11. In this case, as mentioned in the background, the processor 106 may correspondingly generate the DFI (which carries the HARQ-ACK feedback information for the uplink transmission) according to the reception results of the uplink transmission (e.g., the reception results of the user signal) , but the disclosure is not limited thereto.

In step S220, the processor 106 may determine at least two DCI for carrying the DFI, wherein each of the at least two DCI is for carrying a group of DFI, and the DFI includes at least two groups of DFI.

In step S230, the processor 106 may transmit the at least two DCI to the terminal device 11.

From another perspective, the processor 106 may be understood as dividing the DFI into the at least two groups of DFI and carry the groups of DFI with the at least two DCI S ₁, …, S _N, wherein N may be the number of the at least two groups of DFI. Afterwards, the processor 106 may control the transceiver 104 to transmit the at least two DCI S ₁, …, S _N to the terminal device 11.

In one embodiment, each DCI may have a first field for carrying the DFI, and the first field may have a predetermined size. In this case, when a size of the DFI is larger than the size of the first field (i.e., the DFI determined in step S210 is too large for one DCI to carry) , the processor 106 may determine the at least two DCI for carrying the DFI.

In another embodiment, when a size of the DFI is larger than a size of DCI (i.e., the DFI determined in step S210 is too large for one DCI to carry) , the processor 106 may determine the at least two DCI for carrying the DFI.

Correspondingly, the processor 106 may divide the DFI, which is too large to be transmitted in one DCI, into multiple groups of DFI, wherein each group of DFI may include a part of the DFI. Next, the processor 106 may use the DCI S ₁, …, S _N to carry the groups of DFI, such that the terminal device 11 receiving the DCI S ₁, …, S _N carrying the groups of DFI may recover the DFI based on the groups of DFI carried by the DCI S ₁, …, S _N.

In one embodiment, the groups of DFI may respectively correspond to the DCI S ₁, …, S _N, and each of the DCI S ₁, …, S _N carries the corresponding group of DFI. For example, the processor 106 may divide the DFI into a first group of DFI and a second group of DFI, and the processor 106 may use a first DCI and a second DCI to carry the first group of DFI and the second group of DFI, respectively, but the disclosure is not limited thereto.

For simplifying the discussions in the following embodiments, the DFI would be assumed to be divided into the first group of DFI and the second group of DFI as taught in the above, but the disclosure is not limited thereto.

In various embodiments, the contents of the HARQ-ACK feedback information carried in the DFI may be different, and the groups of DFI may be correspondingly determined.

In a first embodiment, the processor 106 may determine the at least two DCI for carrying the DFI when the DFI is for carrying HARQ-ACK feedback information from at least two carriers. Specifically, the terminal device 11 may perform the uplink transmission via at least two configured/active uplink carriers, and each of the groups of DFI may carry HARQ-ACK feedback information for all HARQ process numbers of at least one of the configured/active uplink carriers. For example, assuming that there are three configured/active uplink carriers characterized as carrier #0, carrier #1 and carrier #2, the first group of DFI may include the HARQ-ACK feedback information for all the HARQ process number of carrier #0, and the second group of DFI may include the HARQ-ACK feedback information for all the HARQ process number of carrier #1 and carrier #2, but the disclosure is not limited thereto.

In a second embodiment, the processor 106 may determine the at least two DCI for carrying the DFI when the DFI is for carrying HARQ-ACK feedback information from both configured uplink grant and scheduled uplink. Specifically, the user signal may indicate a plurality of configured grant configurations (e.g., the configured uplink grant or the scheduled uplink grant) , and each of the groups of DFI may carry HARQ-ACK feedback information for all HARQ process numbers of at least one of the configured grant configurations. For example, assuming that there are two configured grant configurations characterized as configuration #0 and configuration #1, the first group of DFI may include the HARQ-ACK feedback information for all the HARQ process number of configuration #0, and the second group of DFI may include the HARQ-ACK feedback information for all the HARQ process number of configuration #1, but the disclosure is not limited thereto.

In a third embodiment, the processor 106 may determine the at least two DCI for carrying the DFI when the DFI is for carrying CBG-based HARQ-ACK feedback information and TB-based HARQ-ACK feedback information. In this case, each of the groups of DFI may include all of the HARQ-ACK feedback information of one of the HARQ-ACK feedback types. For example, assuming that the DFI includes TB-based HARQ-ACK feedback information and CBG-based HARQ-ACK feedback information, the first group of DFI may include the TB-based HARQ-ACK feedback information, and the second group of DFI may include the CBG-based HARQ-ACK feedback information, but the disclosure is not limited thereto.

In a fourth embodiment, the processor 106 may determine the at least two DCI for carrying the DFI when the DFI is for carrying HARQ-ACK feedback information from at least two codewords. Specifically, the user signal may include a plurality of codewords, and each of the groups of DFI carries HARQ-ACK feedback information for all HARQ process numbers of at least one of the codewords. For example, assuming that the maximum codeword number is two, codeword #0 and codeword #1, the first group of DFI may include the HARQ-ACK feedback information for all the HARQ process number of codeword #0, and the second group of DFI may include the HARQ-ACK feedback information for all the HARQ process number of codeword #1, but the disclosure is not limited thereto.

In a fifth embodiment, the processor 106 may determine the at least two DCI for carrying the DFI when the DFI is for carrying HARQ-ACK feedback information corresponding to at least two HARQ process IDs, and the number of the at least two HARQ process IDs is larger than a threshold (which may be designed based on the requirements of the designer) . Specifically, the DFI may include at least two HARQ process IDs to be fed back, the HARQ process IDs are divided into a plurality of process groups, and each of the groups of DFI may carry HARQ-ACK feedbacks for all HARQ process IDs of at least one of the process groups. For example, assuming that the HARQ process IDs can be divided into two process groups characterized as process group #0 and process group #1, the first group of DFI may include the HARQ-ACK feedback information for all the HARQ process IDs in process group #0, and the second group of DFI may include the HARQ-ACK feedback information for all the HARQ process IDs in process group #1, but the disclosure is not limited thereto.

In a sixth embodiment, the groups of DFI may be determined based on the maximum size of the DCI for carrying the DFI. For example, the maximum size of the DCI for carrying the DFI may be characterized as L, the size of the DFI is characterized as S, and S > L. In one embodiment, in response to S≥2L, the first group of DFI may be designed to includeD ₀, D ₁, …, D _L-1, and the second group of DFI may be designed to include D _L, D _L+1, …D _2L-1, wherein D _i is an i-th xx.

In addition, in the embodiments where L<S<2L, the groups of DFI may be determined in various ways. For example, the first group of DFI may be designed to include D ₀, D ₁, …, D _L-1, and the second group of DFI may be designed to include D _L, D _L+1, …D _S-1. For another example, the first group of DFI may be designed to include D ₀, D ₁, …, D _{ceil (S/2) -1}, and the second group of DFI may be designed to include D _ceil (S/2) , D _{ceil (S/2) +1}, …D _S-1, wherein ceil (·) is a ceiling function. For yet another example, the first group of DFI may be designed to include D ₀, D ₁, …, D _{floor (S/2) -1}, and the second group of DFI may be designed to includeD _floor (S/2) , D _{floor (S/2) +1}, …D _S-1, wherein floor (·) is a floor function.

In the sixth embodiment, the size of each of the groups of DFI may be padded to the maximum size of the DCI for carrying the DFI (i.e., L) , but the disclosure is not limited thereto.

In a seventh embodiment, the groups of DFI may be determined based on the maximum size of the DCI for carrying the DFI and HARQ-ACK feedback type. Specifically, the DFI may include a plurality of HARQ-ACK information bits belonging to a plurality of HARQ-ACK feedback types (e.g., CBG-based HARQ-ACK information and TB-based HARQ-ACK information) , and a HARQ-ACK codebook of the DFI may be determined according to the HARQ-ACK information bits belonging to each of the HARQ-ACK feedback types. For example, assuming that the DFI includes TB-based HARQ-ACK feedback and CBG-based HARQ-ACK feedback, the HARQ-ACK codebook of the DFI to be transmitted may be determined according to the TB-based HARQ-ACK information bits and CBG-based HARQ-ACK information bits. Further, assuming that the maximum size of the DCI for carrying the DFI is L, the size of the DFI to be transmitted is S, the mechanism stated in the sixth embodiment can be used to determine the first group of DFI and the second group of DFI, which would not be repeated herein.

In some embodiments, the groups of DFI may be determined based on radio resource control (RRC) configuration parameters, but the disclosure is not limited thereto.

In some embodiments, the processor 106 may determine a first indicator in the DCI for indicating the group ID of the DFI. In one embodiment, the first indicator may be a newly added indication field in the corresponding DCI, wherein the size of the newly added indication field may include M bits (M≥1) . For example, assuming that there are four groups of DFI respectively carried in four DCI, M may include 2 bits for indicating the group ID of each group of DFI, e.g., 00, 01, 10, 11, but the disclosure is not limited thereto. In addition, if the groups of DFI are determined based on the configured grant configurations, the M bits may be used to indicate the configured grant configuration index which is associated with the group ID, but the disclosure is not limited thereto.

In another embodiment, the first indicator may be a reserved indication field in the corresponding DCI, e.g., UL/SUL (Supplementary Uplink) indicator, carrier indicator, or bandwidth part indicator, etc. For example, if the groups of DFI are determined based on uplink carrier, then the carrier indicator may be used as group ID, but the disclosure is not limited thereto.

In yet another embodiment, the first indicator may be a combination of indication fields for transmission scheduling in the corresponding DCI. The indication fields for transmission scheduling may include at least one of the following indication field: new data indicator field, HARQ process number, Redundancy version, Modulation and coding scheme, Frequency domain resource assignment, Time domain resource assignment, UL/SUL indicator, Carrier indicator, Bandwidth part indicator, Frequency hopping flag, UL DAI (downlink assignment index) , Sounding Reference Signal (SRS) resource indicator, Precoding information and number of layers, Antenna ports, SRS request, channel state information (CSI) request, CBG transmission information (CBGTI) , PTRS-DMRS (Demodulation Reference Signal-Phase Tracking Reference Signal) association, beta-offset indicator, DMRS sequence initialization, UL-SCH indicator.

For example, “Frequency hopping flag” may be interpreted as group ID. If “Frequency hopping flag” is set to “0” , it means that the corresponding group of DFI is the group of DFI #0. If “Frequency hopping flag” is set to “1” , it means the corresponding group of DFI is the group of DFI #1, but the disclosure is not limited thereto.

For better understanding the concept in the above, FIG. 3A to FIG. 3C would be used as an example for discussion. See FIG. 3A, which shows the groups of DFI in DFI according to an embodiment of the disclosure. In FIG. 3A, the DFI 310 with a large size may be divided into a plurality of groups of DFI, e.g., DFI group #0, DFI group #1, wherein DFI group #0 may include multiple HARQ-ACK information bits a0, a1, a2, …, and DFI group #1 may include multiple HARQ-ACK information bits b0, b1, b2, …, etc.

In different embodiments, the sizes of DFI group #0 and DFI group #1 may be the same or different. For example, assuming that the maximum number of HARQ processes of each carrier is the same, the DFI group #0 may include the HARQ-ACK feedbacks for all the HARQ process number of carrier #0, and the DFI group #1 may include the HARQ-ACK feedbacks for all the HARQ process number of carrier #1. In this case, the sizes of DFI group #0 and DFI group #1 can be the same. For another example, DFI group #0 may include the HARQ-ACK feedbacks for all the HARQ process number of carrier #0, and DFI group #1 may include the HARQ-ACK feedbacks for all the HARQ process number of carrier #1 and carrier #2. In this case, the sizes of DFI group #0 and DFI group #1 can be different.

See FIG. 3B, which shows the structure of DCI according to an embodiment of the disclosure. As could be observed in FIG. 3B, one DCI may include the aforementioned first indicator and the group of DFI to be carried in the DCI, wherein the first indicator may indicate the group ID of the group of DFI.

See FIG. 3C, which shows the contents of DCI according to FIG. 3A and FIG. 3B. In the embodiment, the DCI #0 is assumed to carry the DFI group #0 in FIG. 3A, and hence the first indicator 321 therein may indicate the group ID of the DFI group #0. Similarly, the DCI #1 is assumed to carry the DFI group #1 in FIG. 3A, and hence the first indicator 331 therein may indicate the group ID of the DFI group #1. Since the DFI 310 may include other groups of DFI (e.g., the group of DFI including the information bits c0, c1, c2) , there may be other DCI for carrying the other groups of DFI, but the disclosure is not limited thereto.

In one embodiment, after the network device 10 transmits the DCI S ₁, …, S _N carrying the groups of DFI corresponding to the same DFI to the terminal device 11, the processor 116 may access the modules stored in the storage circuit 112 to implement the method for HARQ-ACK transmission in NR-U provided in the disclosure, which would be further discussed in the following.

See FIG. 4, which shows a flow chart of the method for HARQ-ACK transmission in NR-U according to an embodiment of the disclosure. The method of this embodiment may be executed by the terminal device 11 in FIG. 1, and the details of each step in FIG. 4 will be described below with the components shown in FIG. 1.

Firstly, in step S410, the processor 116 may performing the uplink transmission to the network device 10 via the transceiver 114. For example, the processor 116 may control the transceiver 114 to send the user signal as mentioned in the above to the network device 10, which would not be repeated herein.

In step S420, the processor 116 may receive at least two DCI S ₁, …, S _N from the network device 10 via the transceiver 114, wherein the DCI S ₁, …, S _N may carry the groups of DFI corresponding to the same DFI generated in step S210 by the network device 10.

In step S430, the processor 116 may retrieve the DFI from the at least two DCI S ₁, …, S _N..

In one embodiment, since each of the DCI S ₁, …, S _N may include a first indicator for indicating the group of DFI therein, the processor 116 may differentiate the DCI S ₁, …, S _N based on the first indicator in each of the DCI S ₁, …, S _N.

For example, if the first indicator in a received DCI indicates that the group ID of the group of DFI therein corresponds to the first group of DFI, the processor 116 may accordingly determine that the received DCI is the first DCI. If the first indicator in another received DCI indicates that the group ID of the group of DFI therein corresponds to the second group of DFI, the processor 116 may accordingly determine that the another received DCI is the second DCI.

For another example, the first group of DFI and the second group of DFI may be assumed to correspond to carrier #p and carrier #q, respectively. In this case, the first indicator in each of the DCI may be a carrier indicator. If the first indicator in a received DCI indicates that the corresponding carrier is the carrier #p, the processor 116 may accordingly determine that the received DCI is the first DCI. If the first indicator in another received DCI indicates that the corresponding carrier is the carrier #q, the processor 116 may accordingly determine that the another received DCI is the second DCI.

In other embodiments, the processor 116 may identify/differentiate the DCI S ₁, …, S _N according to other implicit information. For example, the network device 10 may be assumed to transmit the first DCI and the second DCI in a first communication resource and a second communication resource, respectively. In this case, in response to determining that a certain DCI is received in the first communication resource, the processor 116 may determine that the certain DCI is the first DCI. Similarly, in response to determining that another certain DCI is received in the second communication resource, the processor 116 may determine that the another certain DCI is the second DCI.

In different embodiments, the first communication resource and the second communication resource may be control resource set (CORESET) or search space, but the disclosure is not limited thereto.

In one embodiment, the processor 116 may identify/differentiate the first DCI and the second DCI according to radio network temporary identity (RNTI) . In detail, the network device 10 may be assumed to respectively scramble the first DCI and the second DCI in a first RNTI and a second RNTI, i.e., the first DCI and the second DCI are addressed to the first RNTI and the second RNTI, respectively. In this case, in response to determining that a certain DCI is received based on the first RNTI, the processor 116 may determine that the certain DCI is the first DCI. Similarly, in response to determining that another certain DCI is received based on the second RNTI, the processor 116 may determine that the another certain DCI is the second DCI.

In one embodiment, the terminal device 11 may have a plurality of specific configurations, and the specific configurations may be divided into a plurality configuration groups by the network device 10. In various embodiments, the specific configurations may include the Physical Downlink Shared Channel (PDSCH) , HARQ processes, or HARQ-ACK information bits. Correspondingly, the configuration groups may include a plurality of PDSCH groups, a plurality of HARQ process groups, or a plurality of HARQ-ACK information bit groups, but the disclosure is not limited thereto.

In one embodiment, the network device 10 may transmit one or more feedback triggering indicator for triggering the terminal device 11 to provide a one-shot HARQ-ACK feedback for the configuration group (s) indicated by the one or more feedback triggering indicator. In response thereto, the processor 116 may access the modules stored in the storage circuit 112 to implement the method for providing HARQ-ACK feedback provided in the disclosure, which would be further discussed in the following.

See FIG. 5, which shows a flow chart of the method for method for HARQ-ACK transmission in NR-U according to an embodiment of the disclosure. The method of this embodiment may be executed by the terminal device 11 in FIG. 1, and the details of each step in FIG. 5 will be described below with the components shown in FIG. 1.

Firstly, in step S510, the processor 116 may control the transceiver 114 to receive the feedback triggering indicator from the network device 10, wherein each of the feedback triggering indicator may indicate one specific configuration group of the configuration groups.

Next, in step S520, the processor 116 may transmit a one-shot HARQ-ACK feedback of the specific configuration group indicated by each of the at least one feedback triggering indicator to the network device 10.

In one embodiment, a HARQ-ACK codebook in each of the configuration groups may be determined according to an order of a HARQ process ID thereof.

For simplifying the discussions in the following embodiments, the specific configurations would be assumed to be divided into a first configuration group and a second configuration, but the disclosure is not limited thereto. In one embodiment, if the feedback triggering indicator from the network device 10 indicates the first configuration group, the first configuration group would be regarded as the specific configuration group, and the processor 116 may transmit a one-shot HARQ-ACK feedback of the first configuration group. In another embodiment, if the feedback triggering indicator from the network device 10 indicates the second configuration group, the second configuration group would be regarded as the specific configuration group, and the processor 116 may transmit a one-shot HARQ-ACK feedback of the second configuration group. In addition, if the feedback triggering indicators from the network device 10 indicate both of the first configuration group and the second configuration group, the first configuration group and the second configuration group would be regarded as the specific configuration groups, and the processor 116 may transmit a one-shot HARQ-ACK feedback of each of the first configuration group and the second configuration group, but the disclosure is not limited thereto.

In the following implementations, the configuration groups may be determined in various ways.

In a first implementation, the terminal device 11may be configured with a plurality of configured/active downlink carriers, and each of the configuration groups may carry HARQ-ACK feedback information for all HARQ process numbers of at least one of the configured/active downlink carriers. For example, assuming that there are three configured/active downlink carriers characterized as carrier #0, carrier #1 and carrier #2, the first configuration group may include the HARQ-ACK feedback information for all the HARQ process number of carrier #0, and the second configuration group may include the HARQ-ACK feedback information for all the HARQ process number of carrier #1 and carrier #2, but the disclosure is not limited thereto.

In a second implementation, the terminal device 11 may include a plurality of HARQ-ACK feedbacks belonging to a plurality of HARQ-ACK feedback types (e.g., CBG-based HARQ-ACK information and TB-based HARQ-ACK information) . In this case, each of the configuration groups may include all of the HARQ-ACK feedback information of one of the HARQ-ACK feedback types. For example, assuming that the HARQ-ACK feedbacks includes TB-based HARQ-ACK feedback information and CBG-based HARQ-ACK feedback information, the first configuration group may include the TB-based HARQ-ACK feedback information, and the second configuration group may include the CBG-based HARQ-ACK feedback information, but the disclosure is not limited thereto.

In a third implementation, the terminal device 11 may be configured with a maximum number of codewords, and each of the configuration groups may carry HARQ-ACK feedback information for all HARQ process numbers of at least one of the codewords. For example, assuming that the maximum codeword number is two, codeword #0 and codeword #1, the first configuration group may include the HARQ-ACK feedback information for all the HARQ process number of codeword #0, and the second configuration group may include the HARQ-ACK feedback information for all the HARQ process number of codeword #1, but the disclosure is not limited thereto.

In a fourth implementation, the terminal device 11may be configured with a plurality of HARQ process IDs to be fed back, the HARQ process IDs to be fed back are divided into a plurality of process groups, and each of the configuration groups may carry HARQ-ACK feedback information for all HARQ process IDs of at least one of the process groups. For example, assuming that the HARQ process IDs can be divided into two process groups characterized as process group #0 and process group #1, the first configuration group may include the HARQ-ACK feedback information for all the HARQ process IDs in process group #0, and the second configuration group may include the HARQ-ACK feedback information for all the HARQ process IDs in process group #1, but the disclosure is not limited thereto.

In a fifth implementation, the configuration groups may be determined based on the maximum payload size in one PUCCH resource/format. For example, the maximum payload size in one PUCCH resource/format may be characterized as K, the size of the HARQ-ACK to be fed back is characterized as T, and T > K. In one embodiment, in response to determining that T≥2K, the first configuration group may be designed to include E ₀, E ₁, …, E _K-1, and the second configuration group may be designed to include E _K, E _K+1, …E _2K-1, wherein E _i is an i-th xx.

In addition, in the embodiments where K<T<2K, the configuration groups may be determined in various ways. For example, the first configuration group may be designed to include E ₀, E ₁, …, E _K-1, and the second configuration group may be designed to include E _K, E _K+1, …, E _T-1. For another example, the first configuration group may be designed to include E ₀, E ₁, …, E _ceil (T/2) _-1, and the second configuration group may be designed to include E _ceil (T/2) , E _{ceil (T/2) +1}, …E _T-1. For yet another example, the first configuration group may be designed to include E ₀, E ₁, …, E _{floor (T/2) -1}, and the second configuration group may be designed to include E _floor (T/2) , E _{floor (T/2) +1}, …E _T-1.

In a sixth implementation, the configuration groups may be determined based on the maximum payload size in one PUCCH resource/format and HARQ-ACK feedback type. Specifically, the HARQ-ACK to be transmitted may include a plurality of HARQ-ACK information bits belonging to a plurality of HARQ-ACK feedback types (e.g., CBG-based HARQ-ACK feedback information and TB-based HARQ-ACK feedback information) , and a HARQ-ACK codebook of the HARQ-ACK to be transmitted may be determined according to the HARQ-ACK information bits belonging to each of the HARQ-ACK feedback types. For example, assuming that the HARQ-ACK to be transmitted includes TB-based HARQ-ACK feedback information and CBG-based HARQ-ACK feedback information, the HARQ-ACK codebook of the HARQ-ACK to be transmitted may be determined according to the TB-based HARQ-ACK information bits and CBG-based HARQ-ACK information bits. Further, assuming that the maximum payload size in one PUCCH resource/format is K, the size of the HARQ-ACK to be transmitted is T, the mechanism stated in the fifth implementation can be used to determine the first configuration group and the second configuration group, which would not be repeated herein.

In some embodiments, the configuration groups may be determined based on RRC configuration parameters, but the disclosure is not limited thereto.

In summary, the embodiment of the disclosure provides a method HARQ-ACK transmission in NR-U, which can be used when the payload size of DFI is too large to be carried in one DCI. Specifically, the method of the disclosure may divide the DFI into multiple groups of DFI with smaller size and carry the groups of DFI with corresponding DCI. With this method, large payload DFI can be transmitted in multiple PDCCH and the performance of each PDCCH can be guaranteed, such that the large payload DFI can be transmitted without performance loss. Therefore, the method provided in the disclosure may be adopted in the 5G NR unlicensed spectrum communications.

It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present disclosure without departing from the scope or spirit of the disclosure. In view of the foregoing, it is intended that the present disclosure cover modifications and variations of this disclosure provided they fall within the scope of the following claims and their equivalents.

Claims

A method for Hybrid Automatic Repeat Request-Acknowledgment (HARQ-ACK) transmission in New Radio Unlicensed (NR-U) , comprising:

determining, by a network device, downlink feedback information (DFI) in accordance with an uplink transmission from a terminal device, wherein the DFI is for carrying HARQ-ACK feedback information for the uplink transmission;

determining, by the network device, at least two downlink control information (DCI) for carrying the DFI, wherein each of the at least two DCI is for carrying a group of DFI, and the DFI comprises: at least two groups of DFI;

transmitting, by the network device, the at least two DCI to the terminal device.
The method according to claim 1, determining, by the network device, at least two DCI, for carrying the DFI, comprises at least one of following:

when a size of the DFI is larger than a size of a first field in DCI, determining, by the network device, at least two DCI, for carrying the DFI, wherein the first field is for carrying the DFI;

when a size of the DFI is larger than a size of DCI, determining, by the network device, at least two DCI, for carrying the DFI, wherein the first field is for carrying the DFI;

when the DFI is for carrying HARQ-ACK feedback information from at least two carriers, determining, by the network device, at least two DCI, for carrying the DFI;

when the DFI is for carrying HARQ-ACK feedback information from two groups, determining, by the network device, at least two DCI, for carrying the DFI;

when the DFI is for carrying HARQ-ACK feedback information from both configured uplink grant and scheduled uplink, determining, by the network device, at least two DCI, for carrying the DFI;

when the DFI is for carrying HARQ-ACK feedback information from at least two codewords, determining, by the network device, at least two DCI, for carrying the DFI;

when the DFI is for carrying HARQ-ACK feedback information corresponding to at least two HARQ process IDs, and a number of the at least two HARQ process IDs is more than a threshold, determining, by the network device, at least two DCI, for carrying the DFI;

when the DFI is for carrying code block group (CBG) based HARQ-ACK feedback information and transport block (TB) based HARQ-ACK feedback information, determining, by the network device, at least two DCI, for carrying the DFI.
The method according to claim 1,

determining, by the network device, the group of DFI in accordance with a Radio Resource Control (RRC) configuration parameters.
The method according to claim 2,

wherein the group of DFI is determined by at least one of following factors:

the maximum size of the DCI for carrying the DFI;

the maximum size of the first field in DCI;

a configured uplink carrier;

an active uplink carrier;

configured grant configurations;

types of the HARQ-ACK feedback;

the codewords,

the HARQ process IDs.
The method according to claim 4, wherein the method further comprises:

determining, by the network device, a first indicator in the DCI for indicating the group ID of the DFI.
The method according to claim 5,

using a reserved indication field in the DCI as the first indicator for indicating the group ID of the DFI;

using an indication field for transmission scheduling in the DCI as the first indicator for indicating the group ID of the DFI.
The method according to claim 6, wherein the first indicator is further for indicating the terminal device to identify the DCI in the at least two DCI.
The method according to claim 1,

wherein at least one of following is for the terminal device to identify the DCI in the at least two DCI:

control resource set (CORESET) , Search Space, the type of Radio Network Temporary Identity RNTI.
A network device, comprising:

a non-transitory storage circuit, storing a plurality of modules;

a transceiver; and

a processor, coupled with the non-transitory storage circuit and the transceiver, accessing the modules to executing following steps:

determining downlink feedback information, DFI in accordance with an uplink transmission from a terminal device, wherein the DFI is for carrying HARQ-ACK feedback information for the uplink transmission;

determining at least two downlink control information, DCI, for carrying the DFI, wherein each of the at least two DCI is for carrying a group of DFI, and the DFI comprises: at least two groups of DFI;

transmitting the at least two DCI to the terminal device via the transceiver.
The network device according to claim 9, wherein:

when a size of the DFI is larger than a size of a first field in DCI, the processor determines at least two DCI, for carrying the DFI, wherein the first field is for carrying the DFI;

when a size of the DFI is larger than a size of DCI, the processor determines at least two DCI, for carrying the DFI, wherein the first field is for carrying the DFI;

when the DFI is for carrying HARQ-ACK feedback information from at least two carriers, the processor determines at least two DCI, for carrying the DFI;

when the DFI is for carrying HARQ-ACK feedback information from two groups, the processor determines at least two DCI, for carrying the DFI;

when the DFI is for carrying HARQ-ACK feedback information from both configured uplink grant and scheduled uplink, the processor determines at least two DCI, for carrying the DFI;

when the DFI is for carrying HARQ-ACK feedback information from at least two codewords, the processor determines at least two DCI, for carrying the DFI;

when the DFI is for carrying HARQ-ACK feedback information corresponding to at least two HARQ process IDs, and a number of the at least two HARQ process IDs is more than a threshold, the processor determines at least two DCI, for carrying the DFI;

when the DFI is for carrying code block group (CBG) based HARQ-ACK feedback information and transport block (TB) based HARQ-ACK feedback information, the processor determines at least two DCI, for carrying the DFI.
The network device according to claim 10, wherein the processor determines the group of DFI in accordance with a Radio Resource Control, RRC configuration parameters.
The network device according to claim 10,

wherein the group of DFI is determined by at least one of following factors:

the maximum size of the DCI for carrying the DFI;

the maximum size of the first field in DCI;

a configured uplink carrier;

an active uplink carrier;

configured grant configurations;

types of the HARQ-ACK feedback;

the codewords,

the HARQ process IDs.
The network device according to claim 12, wherein the processor further determines a first indicator in the DCI for indicating the group ID of the DFI.
The network device according to claim 13, wherein:

the processor uses a reserved indication field in the DCI as the first indicator for indicating the group ID of the DFI;

the processor uses an indication field for transmission scheduling in the DCI as the first indicator for indicating the group ID of the DFI.
The network device according to claim 14, wherein the first indicator is further for indicating the terminal to identify the DCI in the at least two DCI.
The network device according to claim 9,

wherein at least one of following is for the terminal device to identify the DCI in the at least two DCI:

control resource set (CORESET) , Search Space, the type of Radio Network Temporary Identity RNTI.
A method for Hybrid Automatic Repeat Request-Acknowledgment (HARQ-ACK) transmission in New Radio Unlicensed (NR-U) , comprising:

performing, by a terminal device, an uplink transmission to a network device, wherein the network device determines downlink feedback information (DFI) in accordance with the uplink transmission, and the DFI is for carrying HARQ-ACK feedback information for the uplink transmission;

receiving, by the terminal device, at least two downlink control information (DCI) from the network device, wherein the at least two DCI are for carrying the DFI, and each of the at least two DCI is for carrying a group of DFI, and the DFI comprises: at least two groups of DFI;

retrieving the DFI from the at least two DCI.
The method according to claim 17, wherein the method further comprises:

determining, by the terminal device, the group ID of the DFI based on a first indicator in the DCI.
The method according to claim 18, wherein:

the first indicator for indicating the group ID of the DFI is a reserved indication field in the DCI;

the first indicator for indicating the group ID of the DFI is an indication field for transmission scheduling in the DCI.
The method according to claim 19, wherein the first indicator is further for indicating the terminal device to identify the DCI in the at least two DCI.
The method according to claim 17, comprising:

identifying the DCI in the at least two DCI based on at least one of control resource set (CORESET) , Search Space, the type of Radio Network Temporary Identity RNTI.
A terminal device, comprising:

a non-transitory storage circuit, storing a plurality of modules;

a transceiver; and

a processor, coupled with the non-transitory storage circuit and the transceiver, accessing the modules to executing following steps:

performing an uplink transmission to a network device via the transceiver, wherein the network device determines downlink feedback information (DFI) in accordance with the uplink transmission, and the DFI is for carrying HARQ-ACK feedback information for the uplink transmission;

receiving at least two downlink control information (DCI) from the network device via the transceiver, wherein the at least two DCI are for carrying the DFI, and each of the at least two DCI is for carrying a group of DFI, and the DFI comprises: at least two groups of DFI;

retrieving the DFI from the at least two DCI.
The terminal device according to claim 22, wherein the processor further performs:

determining, by the terminal device, the group ID of the DFI based on a first indicator in the DCI.
The terminal device according to claim 23, wherein:

the first indicator for indicating the group ID of the DFI is a reserved indication field in the DCI;

the first indicator for indicating the group ID of the DFI is an indication field for transmission scheduling in the DCI.
The terminal device according to claim 24, wherein the first indicator is further for indicating the terminal device to identify the DCI in the at least two DCI.
The terminal device according to claim 23, wherein the processor identifies the DCI in the at least two DCI based on at least one of control resource set (CORESET) , Search Space, the type of Radio Network Temporary Identity RNTI.