CN113439399B

CN113439399B - Radio link adaptation in wireless networks

Info

Publication number: CN113439399B
Application number: CN201980092136.0A
Authority: CN
Inventors: 陶涛; 刘建国; 孟艳; K·霍利
Original assignee: Nokia Shanghai Bell Co Ltd; Nokia Solutions and Networks Oy
Current assignee: Nokia Shanghai Bell Co Ltd; Nokia Solutions and Networks Oy
Priority date: 2019-02-15
Filing date: 2019-02-15
Publication date: 2023-07-25
Anticipated expiration: 2039-02-15
Also published as: WO2020164128A1; CN113439399A

Abstract

Embodiments of the present disclosure relate to hybrid automatic repeat request (HARQ) feedback. In an example embodiment, the method includes: selecting, at the network device, a retransmission feedback mode from a first feedback mode and a second feedback mode, the first feedback mode being used for Transport Block (TB) level feedback for the terminal device and the second feedback mode being used for a combination of TB level feedback and CBG level feedback for the terminal device; generating control information based at least in part on the retransmission feedback pattern; and transmitting the control information to the terminal device. In this way, the overhead of retransmission feedback will be reduced and the flexibility of retransmission feedback can be improved.

Description

Radio link adaptation in wireless networks

Technical Field

Embodiments of the present disclosure relate generally to the field of telecommunications and, more particularly, relate to an apparatus, method, device, and computer readable storage medium for controlling retransmission feedback.

Background

Wireless communication networks are widely deployed to provide various communication services. These wireless telecommunication networks may include one or more User Equipments (UEs) and one or more Base Stations (BSs). In a New Radio (NR) network, a UE may transmit one or more data subframes to a BS over an unlicensed spectrum. When the UE receives NACK feedback for a corresponding HARQ process via downlink control information (e.g., downlink Feedback Information (DFI)), the UE may autonomously initiate retransmission for the HARQ process that was originally transmitted via a grant (CG) mechanism for configuration of the NR unlicensed spectrum.

In CG mechanisms, UEs are configured with persistent or semi-Persistent (PUSCH) resource allocations, as well as other necessary transmission parameters. The resource allocation may be periodic. The UE may transmit on the configured grant PUSCH resources only when the UE has data to transmit, and in some cases, only when the UE does not have any scheduled physical uplink control channel PUSCH resources available. The gNB blindly detects whether there is a configured grant PUSCH transmission on the configured resource. One of the benefits of the configured authorization mechanism is reduced latency. There are other similar mechanisms, such as autonomous uplink transmissions in LTE.

In order to improve efficiency and reduce latency in NR networks, a concept called Code Block Group (CBG) based transmission is introduced, which essentially divides large Transport Blocks (TBs) into smaller groups. Since each group contains at least one Code Block (CB), the group is referred to as a Code Block Group (CBG). Currently, DFI may provide CBG level feedback indication, and UE may retransmit failed CBG based on received DFI. However, such feedback mechanisms may introduce unnecessary overhead and are not flexible enough.

Disclosure of Invention

In general, embodiments of the present disclosure relate to a method for controlling retransmission feedback and a corresponding communication device.

In a first aspect, a method for communication is provided. The method comprises the following steps: a retransmission feedback mode is selected at the network device from a first feedback mode and a second feedback mode, the first feedback mode being used for TB level feedback for the terminal device and the second feedback mode being used for a combination of TB level feedback and CBG level feedback for the terminal device. The method also includes generating control information based at least in part on the retransmission feedback pattern. The method further comprises transmitting control information to the terminal device.

In a second aspect, embodiments of the present disclosure provide a method for communication. The method comprises the following steps: control information is received at the terminal device from the network device, the control information indicating a retransmission feedback mode selected from a first feedback mode and a second feedback mode, the first feedback mode being used for TB level feedback for the terminal device and the second feedback mode being used for a combination of TB level feedback and CBG level feedback for the terminal device. The method further includes performing retransmission based on the control information.

In a third aspect, embodiments of the present disclosure provide an apparatus. The apparatus includes at least one processor; and at least one memory including computer program code; the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to select, at the network device, a retransmission feedback mode from a first feedback mode and a second feedback mode, the first feedback mode being used for TB level feedback for the terminal device, the second feedback mode being used for a combination of TB level feedback and CBG level feedback for the terminal device. The apparatus is further caused to generate control information based at least in part on the retransmission feedback pattern. The device is also caused to transmit control information to the terminal device.

In a fourth aspect, embodiments of the present disclosure provide an apparatus. The apparatus includes at least one processor; and at least one memory including computer program code; the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to receive, at the terminal device, control information from the network device, the control information indicating a retransmission feedback mode selected from a first feedback mode and a second feedback mode, the first feedback mode being used for TB level feedback for the terminal device and the second feedback mode being used for a combination of TB level feedback and CBG level feedback for the terminal device. The device is further caused to perform retransmission based on the control information.

In a fifth aspect, embodiments of the present disclosure provide an apparatus for communication. The device comprises: means for selecting, at the network device, a retransmission feedback mode from a first feedback mode and a second feedback mode, the first feedback mode being used for TB level feedback for the terminal device and the second feedback mode being a combination of TB level feedback and CBG level feedback for the terminal device. The apparatus also includes means for generating control information based at least in part on the retransmission feedback pattern. The apparatus further comprises means for transmitting control information to the terminal device.

In a sixth aspect, embodiments of the present disclosure provide an apparatus for communication. The device comprises: means for receiving control information from the network device at the terminal device, the control information indicating a retransmission feedback mode selected from a first feedback mode and a second feedback mode, the first feedback mode being used for TB level feedback for the terminal device and the second feedback mode being used for a combination of TB level feedback and CBG level feedback for the terminal device. The apparatus further includes means for performing retransmission based on the control information.

In a seventh aspect, embodiments of the present disclosure provide a computer-readable storage medium. The computer readable storage medium comprises program instructions stored thereon which, when executed by a processor of a device, cause the device to perform a method according to the first or second aspect.

Other features and advantages of embodiments of the present disclosure will be apparent from the following description of the particular embodiments, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the embodiments of the disclosure.

Drawings

Embodiments of the present disclosure are presented by way of example and their advantages are explained in more detail below with reference to the drawings, in which

Fig. 1 shows a schematic diagram of a communication system according to an embodiment of the present disclosure;

fig. 2 shows a block diagram of a codebook for HARQ feedback;

FIG. 3 illustrates a schematic diagram of interactions between devices according to an embodiment of the present disclosure;

FIG. 4 illustrates a flow chart of a method implemented at a device according to an embodiment of the disclosure;

fig. 5 shows a block diagram of an example bitmap for HARQ feedback, according to an embodiment of the present disclosure;

fig. 6 shows a block diagram of an example bitmap for HARQ feedback, according to an embodiment of the present disclosure;

fig. 7 shows a block diagram of an example codebook for HARQ feedback according to an embodiment of the present disclosure;

fig. 8 illustrates a block diagram of an example bitmap for HARQ feedback, according to an embodiment of the present disclosure;

fig. 9 shows a block diagram of an example codebook for HARQ feedback according to an embodiment of the present disclosure;

FIG. 10 illustrates a flow chart of a method implemented at a device according to an embodiment of the disclosure;

FIG. 11 shows a schematic diagram of an apparatus according to an embodiment of the present disclosure; and

fig. 12 illustrates a block diagram of an example computer-readable medium, according to some embodiments of the disclosure.

The same or similar reference numbers will be used throughout the drawings to refer to the same or like elements.

Detailed Description

The subject matter described herein will now be discussed with reference to several example embodiments. It should be understood that these embodiments are discussed only to enable those skilled in the art to better understand and thus practice the subject matter described herein, and are not meant to imply any limitation on the scope of the subject matter.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises," "comprising," "includes," and/or "including" when used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

It should also be noted that in some alternative implementations, the functions/acts noted may occur out of the order noted in the figures. For example, two functions or acts shown in succession may in fact be executed concurrently or the acts may sometimes be executed in the reverse order, depending upon the functionality/acts involved.

As used herein, the term "communication network" refers to a network that conforms to any suitable communication standard, such as Long Term Evolution (LTE), LTE-advanced (LTE-a), wideband Code Division Multiple Access (WCDMA), high Speed Packet Access (HSPA), and the like. Furthermore, communication between the terminal device and the network device in the communication network may be performed according to any suitable generation communication protocol, including, but not limited to, first generation (1G), second generation (2G), 2.5G, 2.75G, third generation (3G), fourth generation (4G), 4.5G, future fifth generation (5G) communication protocols, and/or any other currently known or future developed protocols.

Embodiments of the present disclosure may be applied to various communication systems. In view of the rapid development of communications, there will of course also be utilization of future types of communication technologies and systems that may embody the present disclosure. The scope of the present disclosure should not be considered limited to only the systems described above. For purposes of illustration, embodiments of the present disclosure will be described with reference to a 5G communication system.

The term "network device" as used herein includes, but is not limited to, a Base Station (BS), gateway, registration management entity, and other suitable devices in a communication system. The term "base station" or "BS" means a node B (NodeB or NB), an evolved NodeB (eNodeB or eNB), an NR NB (also called a gNB), a Remote Radio Unit (RRU), a Radio Head (RH), a Remote Radio Head (RRH), a relay, a low power node such as a femto, pico, etc.

The term "terminal device" as used herein includes, but is not limited to, "User Equipment (UE)" and other suitable terminal devices capable of communicating with a network device. For example, a "terminal device" may refer to a terminal, mobile Terminal (MT), subscriber Station (SS), portable subscriber station, mobile Station (MS), or Access Terminal (AT).

The term "circuitry" as used herein may refer to one or more or all of the following:

(a) Hardware-only circuit implementations (such as implementations in analog and/or digital circuitry only) and

(b) A combination of hardware circuitry and software, such as (as applicable):

(i) A combination of analog and/or digital hardware circuit(s) and software/firmware; and

(ii) Any portion of the hardware processor(s) having software (including digital signal processor (s)), software, and memory(s) that work together to cause a device (such as a mobile phone or server) to perform various functions; and

(c) Hardware circuit(s) and/or processor(s), such as microprocessor(s) or a portion of microprocessor(s), that require software (such as firmware) to operate, but software may not be present when software is not required for operation.

The definition of circuitry applies to all uses of this term in this application, including in any claims. As another example, as used in this application, the term circuitry also encompasses hardware-only circuitry or a processor (or multiple processors) or an implementation of hardware circuitry or a portion of a processor and its (or their) accompanying software and/or firmware. The term circuitry also encompasses (e.g., and if applicable to the particular claim element) a baseband integrated circuit or processor integrated circuit or server for a mobile device, a cellular network device, or a similar integrated circuit in other computing or network devices.

Fig. 1 illustrates an example communication network 100 in which embodiments of the present disclosure may be implemented. The network 100 includes a network device 110 and terminal devices 120-1 and 120-2 (hereinafter collectively referred to as terminal devices 120 or individually referred to as terminal devices 120) served by the network device 110. The service area of network device 110 is referred to as cell 102. It will be understood that the number of network devices and terminal devices is for illustration purposes only and is not meant to be limiting in any way. Network 100 may include any suitable number of network devices and terminal devices suitable for implementing embodiments of the present disclosure. Although not shown, it should be understood that one or more terminal devices may be in cell 102 and served by network device 110.

Communications in network 100 may conform to any suitable standard including, but not limited to, long Term Evolution (LTE), LTE-evolution, LTE-advanced (LTE-a), wideband Code Division Multiple Access (WCDMA), code Division Multiple Access (CDMA), global system for mobile communications (GSM), and the like. Furthermore, the communication may be performed according to any generation communication protocol currently known or developed in the future. Examples of communication protocols include, but are not limited to, first generation (1G), second generation (2G), 2.5G, 2.75G, third generation (3G), fourth generation (4G), 4.5G, fifth generation (5G) communication protocols.

In general, to bring higher efficiency and reduce latency in NR networks, terminal devices may transmit data in the form of CBGs over an unlicensed spectrum to network devices via an uplink channel (such as PUSCH). These CBGs will be decoded by the network device and the network device will send HARQ feedback for each individual group.

The advantage of this approach is that since NR will support a huge Transport Block Size (TBS) and the scheduler typically operates with a target of 10% BLER. This means that if the terminal device transmits huge TBS data, about 10% of this data will be retransmitted. Unlike LTE, if the transmission gets a NACK, the entire TB does not need to be retransmitted. But only those CBGs that network device 110 failed to decode are retransmitted.

To support CBG-based retransmissions in the configured grant resources, HARQ feedback in the configured grant downlink feedback information (CG-DFI) will need to be updated to include the CBG feedback information. In further enhanced licensed assisted access (feLAA), a codebook in the DFI is employed to indicate TB level ACK/NACK (a/N) for all HARQ processes, where the codebook size scales with the number of HARQ processes. Since LBT is unreliable, making codebook design based on deterministic timing relationship between CG-PUSCH and HARQ feedback challenging, it is expected that the same codebook design principles will also be used for NR-U. This means that in NR CG-DFI, HARQ feedback for all HARQ processes is desired. However, in some cases, CBG level feedback including all HARQ processes may make the desired control information payload size very large, making it difficult to include all feedback in one DCI. For example, when the terminal device is configured with 8 HARQ processes and 8 CBGs per TB for the grant of configuration, a 64-bit codebook in CG-DFI will be caused. Thus, in the current NR DCI format 0_0 and format 0_1, there is not a large enough payload to accommodate CBG level HARQ feedback for all HARQ processes.

Conventionally, in HARQ feedback procedures, one possible solution for CGB-level HARQ feedback is to split information across multiple DCIs. This means that the CBG-based feedback payload for all HARQ processes is divided into a plurality of parts and then encapsulated into a plurality of DCIs. However, such a solution does not address the high feedback overhead in CG-DFI nor does it attempt to compress the CG-DFI overhead.

Another possible solution for HARQ feedback is to use a hybrid codebook. In this solution, network device 110 may provide a combination of TB level feedback and CBG level feedback in a codebook. Fig. 2 shows a block diagram of a codebook 200 for HARQ feedback. To indicate whether a/N of TB level or a/N of CBG level is adopted for each HARQ process, a bit map may be included in CG-DFI. Furthermore, in order to simplify DFI blind decoding at the terminal device side, the DFI payload should have a predetermined semi-static size. In this possible solution, the DFI may contain bits for CBG feedback for a predetermined number of HARQ processes (e.g., for 3 HARQ processes), as shown in fig. 2. However, this potential solution may cause useless overhead in case only some HARQ processes have HARQ feedback to be processed and those processes are decoded correctly at the network device, since the number of actually required HARQ feedback bits changes dynamically. On the other hand, it may sometimes be necessary to provide CBG based HARQ feedback for more than (exemplary) 3 HARQ processes. In these cases, this possible solution is limited by the ability to provide CBG feedback.

To address at least some of the above problems and other potential problems, in accordance with embodiments of the present disclosure, a solution for retransmission feedback is presented. In this solution, the network device 110 may select a retransmission feedback mode from the first feedback mode and the second feedback mode. In the first feedback mode, network device 110 need only perform TB level feedback, and in the second feedback mode, network device 110 may perform a combination of TB level feedback and CBG level feedback. Thus, network device 110 may transmit CBG level HARQ feedback on demand. Since it is most common that all Code Blocks (CBs) are decoded correctly, HARQ feedback overhead can be significantly reduced by avoiding the use of large payload size DFIs to carry both TB level feedback and CBG level feedback at all times.

Principles and implementations of the present disclosure will be described in detail below with reference to fig. 3, fig. 3 showing a schematic diagram of an interaction 300 according to an embodiment of the present disclosure. Interaction 300 may be implemented on any suitable device. For illustrative purposes only, the interaction 300 is described as being implemented at the terminal device 120 and the network device 110.

The network device 110 selects 310 a retransmission feedback mode by taking into account the requirements of CBG level HARQ feedback. Network device 110 may select a first feedback mode that is used for TB level feedback. In the first feedback mode, the network device 110 may transmit a retransmission feedback mode in one transmission of control information, for example, using one DCI. In some embodiments, the control information may be CG-DFI or other suitable type of downlink information.

Network device 110 may also select a second feedback mode that is used for a combination of TB level feedback and CBG level feedback. In the second mode, the network device 110 may transmit feedback information, such as the first CG-DFI and the second CG-DFI, the third CG-DFI, and the fourth CG-DFI, using two DCIs. The first CG-DFI/third CG-DFI may be used to indicate HARQ feedback codebook structures in the second CG-DFI/fourth DCI.

After selecting the retransmission feedback mode, the network device 110 generates 320 control information. If there is no CBG level HARQ feedback, the network device 110 generates a bit map in one CG-DFI to indicate TB level HARQ feedback. Otherwise, the network device 110 generates a bitmap in the first CG-DFI/third CG-DFI and a codebook in the second CG-DFI/fourth CG-DFI.

The network device 110 transmits 330 the generated control information to the terminal device 120. In some embodiments, the control information may be transmitted on a Physical Downlink Control Channel (PDCCH).

The terminal device 120 receives 330 the control information. In some embodiments, the terminal device 120 performs a blind decoding process. The terminal device 120 extracts the control information and obtains a retransmission feedback pattern. The terminal device 120 may perform 340 retransmission based on the control information.

In some embodiments, if network device 110 receives a PUSCH transmission from terminal device 120, network device 110 may notify terminal device 120 of a retransmission feedback mode. Accordingly, the terminal device 120 may perform retransmission based on the retransmission feedback mode.

The operation at the network device 110 will be discussed below with reference to fig. 4-9.

Fig. 4 shows a flow chart of a method 400 according to an embodiment of the present disclosure. Method 400 may be implemented on any suitable device. For illustrative purposes only, the method 400 is described as being implemented at the network device 110.

At block 410, the network device 110 selects a retransmission feedback mode from the first feedback mode and the second feedback mode. The first feedback mode may be used for TB level feedback for the terminal device 120 and the second feedback mode may be used for a combination of TB level feedback and CBG level feedback for the terminal device 120.

In some embodiments, network device 110 selects the retransmission feedback mode based on: the state of the network, predefined rules between the network device 110 and the terminal device 120, or the result of decoding, etc.

At block 420, network device 110 generates control information based on the selected retransmission feedback mode. The control information may be generated in a variety of ways.

In some embodiments, network device 110 may select the first feedback mode to perform only TB level feedback. In this case, the network device 110 generates control information including a first bit map for the HARQ process between the network device 110 and the terminal device 120. In some embodiments, the first bitmap includes a TB level ACK or a TB level NACK for the HARQ process. That is, the network device 110 only needs to transmit one DCI. The first bitmap for the HARQ process may be contained in this DCI. An example of such a DCI structure will be discussed with reference to fig. 5.

It should be noted that in some embodiments, the first bitmap may include an indication of TB level ACK or TB level NACK for part or all of the HARQ processes.

In this way, the first DCI may reuse NR DCI format 0_0, which has a small payload size. Because the first DCI is important, network device 110 may transmit the first DCI using a high aggregation level. The PDCCH capacity will not be increased much due to the small payload size. Thus, the overhead of retransmitting feedback will be reduced.

Alternatively, in some embodiments, network device 110 may select a second feedback mode to perform a combination of TB level feedback and CBG level feedback. In this case, the network device may use two DCIs for the second feedback mode.

In some embodiments, if network device 110 selects the second feedback mode as the retransmission feedback mode, network device 110 generates control information including the second bitmap and the first feedback codebook. The second bit map indicates a feedback level for the HARQ process, and the first feedback codebook includes a plurality of portions corresponding to the HARQ process, and a size of each portion is associated with a respective feedback level for the HARQ process.

In some embodiments, the second bitmap may be transmitted in the first DCI and the first feedback codebook may be transmitted in the second DCI. In some embodiments, the first DCI may include a first indication of the presence of a first feedback codebook. After receiving the first indication, the terminal device 120 may detect the first feedback codebook based on the first indication.

Alternatively or additionally, in some embodiments, the network device 110 may not transmit the first indication. In this case, the terminal device 120 performs a blind decoding process by detecting a search space on control information including one or more DCIs. Based on the number of detected DCI(s) and other optional auxiliary information, such as the format of the DCI(s), the search space of the DCI(s), or one or more indications, e.g., an indication for a first feedback mode, an indication of the presence of a first feedback codebook, an indication of the presence of a second feedback codebook, or an indication that a third DCI includes a third bitmap, terminal device 120 may determine a retransmission feedback mode.

In this way, when CBG level feedback is required, DCI formats supporting a sufficiently large payload (e.g., NR DCI format 0_1) may be utilized for transmission. Because CBG level feedback is not transmitted periodically but only when actually needed, it is not necessary to overcompresse CBG level feedback.

The detailed structure of the first DCI and the second DCI will be discussed with reference to fig. 6 and 7.

Alternatively, in some embodiments, if network device 110 selects the second feedback mode as the retransmission feedback mode, network device 110 generates the third bitmap and the second feedback codebook. The third bitmap may include an indication of a TB level ACK for the corresponding HARQ process or an indication for retransmission. The second feedback codebook includes a fourth bit map indicating a feedback level of the first HARQ process corresponding to the indication of the retransmission.

In some embodiments, if the feedback level of the first HARQ process indicated by the fourth bitmap is a CBG level, the second feedback codebook may further include a fifth bitmap corresponding to the first HARQ process. The fifth bit map includes an indication of CBG level ACK or CBG level NACK for the first HARQ process.

In some embodiments, the third bitmap is transmitted in a third DCI and the second feedback codebook is transmitted in a fourth DCI.

In this way, when CBG level feedback is required, DCI formats supporting a sufficiently large payload (e.g., NR DCI format 0_1) may be utilized for transmission. Because CBG level feedback is not transmitted periodically but only when actually needed, there is no need to overcompresse CBG level feedback.

The detailed structure of the third DCI and the fourth DCI will be discussed with reference to fig. 8 and 9.

At block 430, the network device 110 transmits control information to the terminal device 120.

In some embodiments, network device 110 transmits the second bitmap in the first DCI and the first feedback codebook in the second DCI.

In some embodiments, network device 110 transmits a third bitmap in a third DCI and a second feedback codebook in a fourth DCI.

In some embodiments, the third DCI further includes at least one of: the second indication of the presence of the second feedback codebook and the third DCI includes a third indication of a third bitmap.

In this way, by avoiding the use of a large size payload at all times, the overhead for retransmission feedback will be reduced. Further, the current DCI format may be reused.

As described above, the network device 110 may select the first feedback mode to perform retransmission feedback and generate one DCI including the first bitmap. Referring to fig. 5, the structure of DCI for the first retransmission feedback mode will be discussed.

Fig. 5 shows a block diagram of a bit map 500 for HARQ feedback. If all HARQ processes only require TB level a/N feedback, network device 110 will only transmit one DCI, such as CG-DFI, as shown in fig. 5. Further, in addition to the first bitmap, the DCI may include other control information (e.g., CIF, transmission power control command, etc.) for configured grant PUSCH operation. The DCI may reuse NR DCI format 0_0, which has a small payload size. Because the first CG-DFI is important, network device 110 may transmit the first DFI using a high aggregation level. Due to the small payload size, it does not increase PDCCH capacity too much.

The bit map 500 shows a bit map of "00011111", and each bit in the bit map indicates ACK ('1') or NACK ('0') information for a corresponding HARQ process. It should be noted that the number of HARQ processes and the value of HARQ feedback (TB-LEVEL) shown with respect to fig. 5 are for illustration purposes only and are not limiting. The number of HARQ processes may be any suitable number and the value of HARQ feedback may be any suitable value. It should also be noted that while one HARQ process corresponds to one bit as shown in fig. 5, in other implementations, one HARQ process may correspond to multiple bits. It should be noted that the HARQ processes may be ordered in the bitmap in various ways, e.g. according to increasing or decreasing order of HARQ process numbers. However, the ordering is predefined to ensure that the bit map is properly interpreted on both the network device and the terminal device.

As described above, the network device 110 may perform retransmission feedback in the second feedback mode. The network device 110 generates a first DCI including a second bitmap and a second DCI including a first feedback codebook. Referring to fig. 6 and 7, detailed structures of the first DCI and the second DCI are discussed below. Fig. 6 shows a block diagram of a bit map 600 for HARQ feedback. Fig. 7 shows a block diagram of a codebook 700 for HARQ feedback. It should be noted that the number of HARQ processes, the value of HARQ feedback, and the value of TB/CBG shown with respect to fig. 6 and 7 are for illustration purposes only and not limitation. The number of HARQ processes may be any suitable number and the value of HARQ feedback and the value of TB/CBG may be any suitable value.

If the network device 110 contains both TB level feedback and CBG level feedback for the terminal device 120 with a configured UL grant transmission, the first DCI and the second DCI (e.g., the first and second CG-DFIs) will be used to indicate HARQ a/N feedback to the terminal device 120. As shown in fig. 6 and 7, the terminal device 120 has 8 HARQ processes for UL transmission. The bit map 600 shows a bit map of "11010111", and each bit in the bit map shows TB level ('1') or CBG level ('0') information for a corresponding HARQ process. The 8-bit bitmap in the first CG-DFI is used to indicate that either TB level a/N or CBG level a/N is employed for each HARQ process. Here, "1" means that the TB level a/N will be provided to the HARQ process, and "0" means that the CBG level a/N will be provided to the HARQ process. Bit map 600 shows that HARQ process #3 and HARQ process #5 will provide CBG level a/N feedback.

The first CG-DFI may reuse NR DCI format 0_0 with a small payload size. Further, the first CG-DFI may include optional one bit information to indicate the presence of the second CG-DFI.

Codebook 700 is an example of a first feedback codebook included in a second CG-DFI. The first feedback codebook for HARQ ACK feedback is determined by: information of a TB level a/N or a CBG level a/N used for each HARQ process and the number of CBGs for each HARQ process, which are indicated in the first CG-DFI. This information is indicated by the network device 110 via RRC signaling or by the terminal device 120 via CG-UCI. As shown in fig. 7, a 14-bit codebook of "00011101110111" in the second CG-DFI is used to indicate HARQ a/N feedback for different HARQ processes. Since HARQ processes #3 and #5 have four CBGs in their TBs, 4 bits of information are used to indicate CBG level a/N feedback for both HARQ processes.

The second CG-DFI may reuse NR DCI format 0_1, which has a relatively large payload size. In addition, the second CG-DFI may include an indication (such as a one bit flag) to indicate that it is the second CG-DFI.

Alternatively, when the network device 110 may perform retransmission feedback in the second feedback mode, the network device 110 may generate a third DCI including a third bitmap and a fourth DCI including a second feedback codebook. Referring to fig. 8 and 9, detailed structures of the third DCI and the fourth DCI are discussed below. Fig. 8 shows a block diagram of a bit map 800 for HARQ feedback. Fig. 9 shows a block diagram of a codebook 900 for HARQ feedback. It should be noted that the number of HARQ processes, the value of ACK/RE-TX and the value of the presence of CBG-based feedback and the value of HARQ feedback shown with respect to fig. 8 and 9 are for illustration purposes only and not limitation. The number of HARQ processes may be any suitable number, and the values of ACK/RE-TX and the value of the presence of CBG-based feedback and the value of HARQ feedback may be any suitable value.

The network device 110 contains both TB level feedback and CBG level feedback for the terminal device 120 with configured UL grant transmission, and both third DCI and fourth DCI (such as third and fourth CG-DFI) are used to indicate HARQ a/N feedback to the terminal device 120. As shown in fig. 8 and 9, the terminal device 120 has 8 HARQ processes for UL transmission. A bit map 800, which shows a "10010111" bit map, is used to indicate TB level ACK or retransmission needs for each HARQ process. Here, "1" indicates TB level ACK, and "0" indicates retransmission need. Further, the third CG-DFI may include a second indication (e.g., one bit) to indicate the presence of a fourth DFI, and an optional indication (e.g., one bit flag) to indicate that the third DCI includes a third bitmap. Upon receiving the second indication, the terminal device 120 may detect a second feedback codebook based on the second indication.

Alternatively or additionally, in some embodiments, the network device 110 may not transmit the second indication. In this case, the terminal device 120 performs a blind decoding process by detecting a search space on control information including one or more DCIs. This procedure is similar to the blind decoding procedure without the first indication and is therefore not described in detail here.

As shown in fig. 9, the fourth CG-DFI first contains an 8-bit bitmap of whether CBG-based feedback is contained in the DFI. The size of the bitmap may correspond to the number of HARQ processes configured for CG-PUSCH operation, or alternatively, the bitmap 800 indicates the number of HARQ processes that need to be retransmitted. Since the third DFI indicates retransmission for HARQ processes #2, #3, and #5 and the fourth DFI contains only CBG-based feedback for HARQ processes #3 and #5, the terminal device 120 determines that a TB-based NACK is indicated for HARQ process # 2. Terminal device 120 determines CBG-based feedback for HARQ processes #3 and # 5. In this example, HARQ processes #3 and #5 have four CBGs. Thus, 16 bits are used to indicate CGB-based feedback for HARQ processes #3 and # 5. The remaining bits of the DFI (e.g., aligned with the DCI 0-1 size) are padded with null bits.

Further, the fourth CG-DFI may include an indication (such as a one bit flag) to indicate that it is the fourth CG-DFI.

The third CG-DFI may reuse NR DCI format 0_0 and the fourth CG-DFI may reuse NR DCI format 0_1.

In this way, the terminal device 120 may perform at least some retransmissions even if it detects only one DFI. In case the terminal device 120 detects only the third DFI, the terminal device 120 interprets its content as a/N based on TB. Furthermore, in case the terminal device 120 detects only the fourth DFI, the terminal device 120 may perform retransmission on its HARQ process including CBG-based HARQ feedback.

New details of the operation of the terminal device 120 will now be discussed with reference to fig. 10. Fig. 10 shows a flowchart of a method 1000 according to an embodiment of the present disclosure. Method 1000 may be implemented on any suitable device. For illustrative purposes only, the method 1000 is described as being implemented at the terminal device 120.

At block 1010, terminal device 120 receives control information from network device 110. The control information may indicate a retransmission feedback mode selected from the first feedback mode and the second feedback mode. The first feedback mode may be used for TB level feedback for the terminal device 120 and the second feedback mode may be used with a combination of TB level feedback and CBG level feedback for the terminal device 120.

In some embodiments, the terminal device 120 determines whether the control information includes a first indication of the presence of the first feedback codebook or a second indication of the presence of the second feedback codebook. If the terminal device 120 determines that the control information includes neither the first nor the second indication, the terminal device 120 extracts the first bitmap from the control information. The first bit map includes an indication of a TB level ACK or a TB level NACK for the HARQ process.

In some embodiments, if the terminal device 120 determines that the control information includes the first indication, the terminal device 120 extracts the second bitmap and the first feedback codebook. The second bit map indicates a feedback level of the HARQ process, and the first feedback codebook includes a plurality of parts corresponding to the HARQ process. The size of the portion is associated with a corresponding feedback level for the HARQ process.

In some embodiments, the terminal device 120 receives the second bitmap in the first DCI and the first feedback codebook in the second DCI on a downlink control channel. In an example, the first DCI may include a first indication. When detecting the first indication from the first DCI, the terminal device 120 may know that the first feedback codebook is present in the second DCI.

In some embodiments, if the terminal device 120 determines that the control information includes the second indication, the terminal device 120 extracts the third bitmap and the second feedback codebook. The third bitmap includes an indication of a TB level ACK for the HARQ process or an indication for retransmission, and the second feedback codebook includes a fourth bitmap indicating a feedback level of the first HARQ process corresponding to the indication for retransmission.

In some embodiments, if the feedback level of the first HARQ process indicated by the fourth bitmap is a CBG level, the second feedback codebook further includes a fifth bitmap corresponding to the first HARQ process. The fifth bitmap may include an indication of a CBG level ACK or a CBG level NACK for the first HARQ process.

In some embodiments, the terminal device 120 receives the third bitmap in the third DCI and the second feedback codebook in the fourth DCI on a downlink control channel.

In some embodiments, the third DCI includes at least one of: the second indication of the presence of the second feedback codebook and the third DCI includes a third indication of a third bitmap.

In block 1020, the terminal device 120 performs retransmission based on the control information.

In some embodiments, the terminal device 120 determines whether the fourth DCI is successfully received. If the fourth DCI is successfully received, the terminal device 120 performs retransmission based at least in part on the third bitmap and the fourth DCI. If the fourth DCI is not successfully received, the terminal device 120 performs retransmission based on the third bitmap.

In some embodiments, if the terminal device 120 determines that the third DCI is not successfully received and at least a portion of the fourth DCI is successfully received, the terminal device 120 performs retransmission based on the fourth and fifth bitmaps in the fourth DCI.

In some embodiments, an apparatus (e.g., network device 110) for performing method 400 may include respective components for performing corresponding steps in method 400. These components may be implemented in any suitable manner. For example, it may be implemented by circuitry or software modules.

In some embodiments, the apparatus includes means for selecting, at the network device, a retransmission feedback mode from a first feedback mode and a second feedback mode, the first feedback mode being used for TB level feedback for the terminal device and the second feedback mode being used for a combination of TB level feedback and CBG level feedback for the terminal device; means for generating control information based at least in part on the retransmission feedback pattern; and means for transmitting the control information to the terminal device.

In some embodiments, the means for generating control information comprises: means for generating control information comprising a first bitmap comprising an indication of a TB level ACK or a TB level NACK for a HARQ process between a network device and a terminal device in response to a first feedback mode being selected as a retransmission feedback mode.

In some embodiments, the means for generating control information comprises: means for generating control information in response to the second feedback mode being selected as the retransmission feedback mode, the control information comprising: a second bitmap for a HARQ process between the network device and the terminal device, a second bitmap indicating a feedback level for the HARQ process, and a first feedback codebook comprising a plurality of portions corresponding to the HARQ process, wherein a size of each portion is associated with a respective feedback level for the HARQ process.

In some embodiments, the means for transmitting control information to the terminal device comprises: means for transmitting a second bitmap in the first DCI and a first feedback codebook transmitted in the second DCI on a downlink control channel.

In some embodiments, the first DCI further includes a first indication of the presence of the first feedback codebook.

In some embodiments, the means for generating control information comprises: means for generating control information in response to the second feedback mode being selected as the retransmission feedback mode, the control information comprising: a third bitmap for a HARQ process between the network device and the terminal device, the third bitmap comprising an indication of a TB level ACK for the HARQ process or an indication for retransmission, and a second feedback codebook comprising a fourth bitmap indicating a feedback level for the first HARQ process corresponding to the indication for retransmission.

In some embodiments, if the feedback level of the first HARQ process indicated by the fourth bit map is a CBG level, the second feedback codebook further comprises: a fifth bit map corresponding to the first HARQ process, the fifth bit map comprising an indication of CBG level ACK or CBG level NACK for the first HARQ process.

In some embodiments, the means for transmitting control information to the terminal device comprises: the apparatus further includes means for transmitting a third bitmap in a third DCI and transmitting a second feedback codebook in a fourth DCI on a downlink control channel.

In some embodiments, an apparatus (e.g., terminal device 120) for performing method 1000 may include respective means for performing corresponding steps in method 1000. These components may be implemented in any suitable manner. For example, it may be implemented by circuitry or software modules.

In some embodiments, the apparatus comprises: means for receiving control information from a network device at a terminal device, the control information indicating a retransmission feedback mode selected from a first feedback mode and a second feedback mode, the first feedback mode being used for TB level feedback for the terminal device and the second feedback mode being used for a combination of TB level feedback and CBG level feedback for the terminal device; and means for performing retransmission based on the control information.

In some embodiments, the means for receiving control information comprises: means for determining whether the control information includes a first indication of the presence of the first feedback codebook or a second indication of the presence of the second feedback codebook; and means for extracting a first bitmap for a HARQ process between the network device and the terminal device from the control information in response to determining that the control information includes neither the first nor the second indication, the first bitmap including an indication of a TB level ACK or a TB level NACK for the HARQ process.

In some embodiments, the apparatus further comprises means for extracting, from the control information, a second bitmap for a HARQ process between the network device and the terminal device and a first feedback codebook indicating a feedback level for the HARQ process in response to determining that the control information includes the first indication, the first feedback codebook comprising a plurality of portions corresponding to the HARQ process, wherein a size of each portion is associated with the respective feedback level for the HARQ process.

In some embodiments, the means for receiving control information from a network device comprises: the apparatus includes means for receiving a second bitmap in a first DCI and a first feedback codebook in a second DCI on a downlink control channel.

In some embodiments, the first DCI includes a first indication.

In some embodiments, the apparatus further comprises: means for extracting, from the control information, a third bitmap for a HARQ process between the network device and the terminal device and a second feedback codebook in response to determining that the control information includes the second indication, the third bitmap including an indication of a TB level ACK for the HARQ process or an indication for retransmission, the second feedback codebook including a fourth bitmap indicating a feedback level for the first HARQ process corresponding to the indication for retransmission.

In some embodiments, if the feedback level of the first HARQ process indicated by the fourth bit map is a CBG level, the second feedback codebook further comprises a fifth bit map corresponding to the first HARQ process, the fifth bit map comprising an indication of a CBG level ACK or a CBG level NACK for the first HARQ process.

In some embodiments, the means for receiving control information from a network device comprises: the apparatus further includes means for receiving a third bit map in a third DCI and a second feedback codebook in a fourth DCI on a downlink control channel.

In some embodiments, the means for performing retransmission based on the control information comprises: means for determining whether the fourth DCI is successfully received; means for performing a retransmission based at least in part on the third bitmap and the fourth DCI in response to determining that the fourth DCI was successfully received; and means for performing retransmission based on the third bitmap in response to determining that the fourth DCI was not successfully received.

In some embodiments, the means for performing the retransmission based on the control information includes means for performing the retransmission based at least in part on a fourth bitmap and a fifth bitmap in the fourth DCI in response to determining that the third DCI was not successfully received and the fourth DCI was successfully received.

Fig. 11 is a simplified block diagram of a device 1100 suitable for implementing embodiments of the present disclosure. Device 1100 may be implemented at network device 110. Device 1100 may also be implemented at terminal device 120.

As shown, device 1100 includes one or more processors 1110, one or more memories 1120 coupled to the processor(s) 1110, one or more transmitters and/or receivers (TX/RX) 1140 coupled to the processor(s) 1110.

Processor 1110 may be of any type suitable for use in a local technology network and may include, by way of non-limiting example, one or more of the following: general purpose computers, special purpose computers, microprocessors, digital Signal Processors (DSPs), and processors based on a multi-core processor architecture. The device 1100 may have multiple processors, such as an application-specific integrated circuit chip that is slaved in time to the clock of the synchronous master processor.

Memory 1120 may be of any type suitable for the local technology network and may be implemented using any suitable data storage technology, such as non-transitory computer readable storage media, semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory, and removable memory, as non-limiting examples.

Memory 1120 stores at least a portion of program 1130. Device 1100 may load program 1130 from a computer readable medium into RAM for execution. The computer readable medium may include any type of tangible, non-volatile memory, such as ROM, EPROM, flash memory, hard disk, CD, DVD, etc. Fig. 12 shows an example of a computer readable medium 1200 in the form of a CD or DVD. The computer-readable medium has program 1130 stored thereon.

TX/RX 1140 is used for two-way communication. TX/RX 1140 has at least one antenna to facilitate communications, but in practice the access nodes referred to in this application may have multiple antennas. The communication interface may represent any interface required to communicate with other network elements.

Assume that program 1130 includes program instructions that, when executed by associated processor 1110, enable device 1100 to operate in accordance with embodiments of the present disclosure, as discussed herein with reference to fig. 5 and 7. That is, embodiments of the present disclosure may be implemented by computer software executable by the processor 1110 of the device 1100, or by hardware, or by a combination of software and hardware.

While this specification contains many specific implementation details, these should not be construed as limitations on the scope of any disclosure or of what may be claimed, but rather as descriptions of features that may be specific to particular embodiments of particular disclosures. Certain features that are described in this specification in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination. Furthermore, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination.

Similarly, although operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In some cases, multitasking and parallel processing may be advantageous. Moreover, the separation of various system components in the embodiments described above should not be understood as requiring such separation in all embodiments, as it should be understood that the described program components and systems can generally be integrated in a single software product or packaged into multiple software products.

Various modifications, adaptations to the foregoing exemplary embodiments of this disclosure will become apparent to those skilled in the relevant arts in view of the foregoing description, when read in conjunction with the accompanying drawings. Any and all modifications will still fall within the scope of the non-limiting and exemplary embodiments of this disclosure. Moreover, other embodiments of the disclosure set forth herein will be apparent to those skilled in the art to which the embodiments of the disclosure pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings.

Therefore, it is to be understood that the embodiments of the present disclosure are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

Claims

1. A method for communication, comprising:

selecting, at a network device, a retransmission feedback mode from a first feedback mode and a second feedback mode, the first feedback mode being used for Transport Block (TB) level feedback for a terminal device and the second feedback mode being used for a combination of TB level feedback and Code Block Group (CBG) level feedback for the terminal device;

generating control information based at least in part on the retransmission feedback pattern; and

and transmitting the control information to the terminal equipment.

2. The method of claim 1, wherein generating the control information comprises:

in response to the first feedback mode being selected as the retransmission feedback mode, the control information is generated that includes a first bitmap for a hybrid automatic repeat request (HARQ) process between the network device and the terminal device, the first bitmap including an indication of a TB level ACK or a TB level NACK for the HARQ process.

3. The method of claim 1, wherein generating control information comprises:

in response to the second feedback mode being selected as the retransmission feedback mode, generating the control information including:

A second bitmap for a HARQ process between the network device and the terminal device, the second bitmap indicating a feedback level for the HARQ process, and

a first feedback codebook comprising a plurality of portions corresponding to the HARQ process, wherein a size of each portion is associated with a respective feedback level for the HARQ process.

4. A method according to claim 3, wherein transmitting the control information to the terminal device comprises:

the second bit map is transmitted in a first Downlink Control Information (DCI) and the first feedback codebook is transmitted in a second DCI on a downlink control channel.

5. The method of claim 4, wherein the first DCI further comprises a first indication of a presence for the first feedback codebook.

6. The method of claim 1, wherein generating control information comprises:

a third bit map for a HARQ process between the network device and the terminal device, the third bit map comprising an indication of a TB level ACK or an indication of a retransmission for the HARQ process, and

A second feedback codebook comprising a fourth bitmap indicating a feedback level of a first HARQ process corresponding to the indication for retransmission.

7. The method of claim 6, wherein if the feedback level of the first HARQ process indicated by the fourth bitmap is the CBG level feedback, the second feedback codebook further comprises:

a fifth bitmap corresponding to the first HARQ process, the fifth bitmap comprising an indication of a CBG level ACK or a CBG level NACK for the first HARQ process.

8. The method of claim 6, wherein transmitting the control information to the terminal device comprises:

the third bit map is transmitted in a third DCI and the second feedback codebook is transmitted in a fourth DCI on a downlink control channel.

9. The method of claim 8, wherein the third DCI further comprises at least one of:

a second indication of the presence of the second feedback codebook, and

the third DCI includes a third indication of the third bitmap.

10. A method for communication, comprising:

receiving, at a terminal device, control information from a network device, the control information indicating a retransmission feedback mode selected from a first feedback mode and a second feedback mode, the first feedback mode being used for TB level feedback for the terminal device and the second feedback mode being used for a combination of TB level feedback and CBG level feedback for the terminal device; and

And performing retransmission based on the control information.

11. The method of claim 10, wherein receiving the control information comprises:

determining whether the control information includes a first indication of the presence of a first feedback codebook or a second indication of the presence of a second feedback codebook; and

in response to determining that the control information includes neither the first nor the second indication, a first bitmap for a HARQ process between the network device and the terminal device is extracted from the control information, the first bitmap including an indication for the HARQ process TB level ACK or TB level NACK.

12. The method of claim 11, further comprising:

extracting, in response to determining that the control information includes the first indication, from the control information:

a second bitmap for a HARQ process between the network device and the terminal device, the second bitmap indicating a feedback level of the HARQ process, and

13. The method of claim 12, wherein receiving the control information from the network device comprises:

on a downlink control channel, the second bitmap is received in a first DCI and the first feedback codebook is received in a second DCI.

14. The method of claim 13, wherein the first DCI includes the first indication.

15. The method of claim 11, further comprising:

extracting, in response to determining that the control information includes the second indication, from the control information:

a third bit map for a HARQ process between the network device and the terminal device, the third bit map comprising an indication of a TB level ACK or an indication of retransmission for the HARQ process, and

16. The method of claim 15, wherein if the feedback level of the first HARQ process indicated by the fourth bitmap is the CBG level feedback, the second feedback codebook further comprises:

17. The method of claim 16, wherein receiving the control information from the network device comprises:

on a downlink control channel, the third bit map is received in a third DCI and the second feedback codebook is received in a fourth DCI.

18. The method of claim 17, wherein the third DCI comprises at least one of:

the second indication of the presence of the second feedback codebook, and

the third DCI includes a third indication of the third bitmap.

19. The method of claim 18, wherein performing the retransmission based on the control information comprises:

determining whether the fourth DCI is successfully received;

responsive to determining that the fourth DCI is successfully received, performing a retransmission based at least in part on the third bitmap and the fourth DCI; and

in response to determining that the fourth DCI is not successfully received, a retransmission is performed based on the third bitmap.

20. The method of claim 17, wherein performing retransmission based on the control information comprises:

In response to determining that the third DCI is not successfully received and the fourth DCI is successfully received, performing a retransmission based at least in part on a fourth bit map and the fifth bit map in the fourth DCI.

21. An apparatus for communication, comprising:

at least one processor; and

at least one memory including computer program code;

the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to perform the method of any of claims 1 to 9.

22. An apparatus for communication, comprising:

at least one processor; and

at least one memory including computer program code;

the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to perform the method of any of claims 10 to 20.

23. A computer readable storage medium comprising program instructions stored thereon, which when executed by a processor of a device, cause the device to perform the method of any of claims 1 to 9.

24. A computer readable storage medium comprising program instructions stored thereon, which when executed by a processor of a device, cause the device to perform the method of any of claims 10 to 20.

25. An apparatus for communication, comprising:

means for selecting, at a network device, a retransmission feedback mode from a first feedback mode and a second feedback mode, the first feedback mode being used for Transport Block (TB) level feedback for a terminal device and the second feedback mode being used for a combination of TB level feedback and Code Block Group (CBG) level feedback for the terminal device;

means for generating control information based at least in part on the retransmission feedback pattern; and

and means for transmitting the control information to the terminal device.

26. An apparatus for communication, comprising:

means for receiving control information from a network device at a terminal device, the control information indicating a retransmission feedback mode selected from a first feedback mode and a second feedback mode, the first feedback mode being used for TB level feedback for the terminal device and the second feedback mode being used for a combination of TB level feedback and CBG level feedback for the terminal device; and

And means for performing retransmission based on the control information.