HARQ feedback method and device in non-terrestrial network

Abstract

The present invention provides a HARQ feedback method and device in a non-terrestrial network, wherein the method comprises: a base station sends a feedback enabling parameter configured for a DL HARQ process to a user equipment, wherein the feedback enabling parameter is used to indicate that the user equipment enables HARQ feedback for the DL HARQ process; a maximum number of transmissions is configured as 1 for each DL HARQ process; after the base station uses the DL HARQ process enabled with HARQ feedback to send DL data, the base station immediately releases the DL HARQ process, and receives HARQ feedback from the user equipment for the DL data after releasing the DL HARQ process. This solution can reduce RTT while retaining HARQ feedback.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of wireless communication technology, and in particular to a hybrid automatic repeat request (HARQ) feedback method and device in non-terrestrial networks (NTN). Background Art

[0002] In the HARQ mechanism, after the base station sends data to the user equipment through the HARQ process, it needs to wait for the feedback from the user equipment. When receiving the negative acknowledgment (NACK, Non-Acknowledgement) feedback from the user equipment, it needs to resend the data. When receiving the positive acknowledgment (ACK, Acknowledgement) feedback from the user equipment, the HARQ process is released. The HARQ mechanism has a round-trip time (Round-Trip Time, RTT).

[0003] As a high-latency network, NTN reduces RTT by disabling downlink (DL) HARQ feedback. However, this method affects the algorithm on the base station side that relies on HARQ feedback. Summary of the invention

[0004] The embodiments of the present invention provide a HARQ feedback method and device in a non-terrestrial network, which can reduce the RTT while retaining the HARQ feedback.

[0005] In a first aspect, an embodiment of the present invention provides a HARQ feedback method in a non-terrestrial network, which is applied to a base station, including:

[0006] Sending a feedback enabling parameter configured for a DL HARQ process to a user equipment, wherein the feedback enabling parameter is used to indicate to the user equipment to enable HARQ feedback for the DL HARQ process; configuring a maximum number of transmissions for each DL HARQ process to be 1;

[0007] After sending DL data by using the DL HARQ process enabled with HARQ feedback, the DL HARQ process is immediately released, and after releasing the DL HARQ process, HARQ feedback from the user equipment for the DL data is received.

[0008] In some embodiments, the feedback enabling parameter is configured for some DL HARQ processes among a plurality of DL HARQ processes allocated to the user equipment.

[0009] In some embodiments, when sending new DL data to the user equipment, a DL HARQ process configured with a feedback enabling parameter is preferentially selected in an idle HARQ pool for sending.

[0010] In a second aspect, an embodiment of the present invention further provides a HARQ feedback device in a non-terrestrial network, which is applied to a base station, and the device includes:

[0011] a resource configuration unit, configured to send a feedback enabling parameter configured for a DL HARQ process to a user equipment, wherein the feedback enabling parameter is used to instruct the user equipment to enable HARQ feedback for the DL HARQ process; and configure a maximum number of transmissions for each DL HARQ process as 1;

[0012] The processing unit is configured to release the DL HARQ process immediately after sending DL data using the DL HARQ process enabled with HARQ feedback, and receive HARQ feedback from the user equipment for the DL data after releasing the DL HARQ process.

[0013] In some embodiments, the resource configuration unit is used to configure the feedback enabling parameter for some DL HARQ processes among a plurality of DL HARQ processes allocated to the user equipment.

[0014] In some embodiments, the processing unit is further configured to preferentially select a DL HARQ process configured with a feedback enabling parameter in an idle HARQ pool for sending new DL data to the user equipment.

[0015] In a third aspect, an embodiment of the present invention further provides an electronic device, including a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the method described in any embodiment of this specification is implemented.

[0016] In a fourth aspect, an embodiment of the present invention further provides a computer-readable storage medium having a computer program stored thereon, which, when executed in a computer, enables the computer to execute the method described in any embodiment of this specification.

[0017] The embodiment of the present invention provides a HARQ feedback method and device in a non-terrestrial network. Since HARQ feedback is disabled in the NTN system, the user equipment enables HARQ feedback for the DL HARQ process by configuring feedback enabling parameters for the DL HARQ process. Since the maximum number of transmissions configured for the DL HARQ process is 1, the base station can immediately release the HARQ process without waiting for HARQ feedback after sending DL data, which can greatly reduce RTT compared to the HARQ mechanism and will not increase RTT additionally compared to the NTN system. Moreover, since the HARQ process is enabled with HARQ feedback, the user equipment will provide HARQ feedback to the base station after receiving DL data. After receiving the HARQ feedback, the base station can provide data basis for the algorithm that relies on the HARQ feedback. It can be seen that this solution reduces the RTT while retaining the HARQ feedback. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 It is a flow chart of a HARQ feedback method in a non-terrestrial network provided by an embodiment of the present invention;

[0020] Figure 2 is a comparison diagram of three scheduling timings provided by an embodiment of the present invention;

[0021] Figure 3 is a hardware architecture diagram of an electronic device provided by an embodiment of the present invention;

[0022] Figure 4 It is a structural diagram of a HARQ feedback device in a non-terrestrial network provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0024] As mentioned above, if DL HARQ feedback is turned off, the user equipment will not perform HARQ feedback for the DL data sent by the base station regardless of whether it is confirmed, and the base station will not refer to the HARQ feedback of the user equipment and will not perform HARQ retransmission, which can greatly reduce the round-trip delay. Then on the base station side, there are algorithms that need to rely on the HARQ feedback of the user equipment. For example, scheduling algorithms such as Adaptive Modulation and Coding (AMC), adaptive RANK of spatial division multiplexing streams, and downlink power control.

[0025] The purpose of the present invention is to reduce the round trip delay while retaining the HARQ feedback, and not to increase the round trip delay compared to the NTN system. In view of the purpose of the invention, the invention concept of the present application is to enable the DL HARQ process to perform HARQ feedback, and the base station does not need to wait for the HARQ feedback. After the DL data is sent, the DL HARQ process can be directly released, and the HARQ feedback of the user equipment for the DL data can still be received. In this way, compared with the NTN system that prohibits HARQ feedback, there is no additional round trip delay, and the HARQ feedback is retained.

[0026] The specific implementation of the above concept is described below.

[0027] Please refer to Figure 1 The embodiment of the present invention provides a HARQ feedback method in a non-terrestrial network, which is applied to a base station. The method includes:

[0028] Step 100: Send a feedback enabling parameter configured for a DL HARQ process to a user equipment, wherein the feedback enabling parameter is used to instruct the user equipment to enable HARQ feedback for the DL HARQ process; and configure a maximum number of transmissions for each DL HARQ process as 1;

[0029] Step 102: After sending DL data using the DL HARQ process enabled with HARQ feedback, immediately release the DL HARQ process, and receive HARQ feedback from the user equipment for the DL data after releasing the DL HARQ process.

[0030] In the embodiment of the present invention, since HARQ feedback is disabled in the NTN system, the user equipment enables HARQ feedback for the DL HARQ process by configuring feedback enabling parameters for the DL HARQ process. Since the maximum number of transmissions configured for the DL HARQ process is 1, the base station can immediately release the HARQ process without waiting for HARQ feedback after sending DL data, which can greatly reduce RTT compared to the HARQ mechanism and will not increase RTT additionally compared to the NTN system; and since the HARQ process is enabled with HARQ feedback, the user equipment will provide HARQ feedback to the base station after receiving DL data, and the base station can provide data basis for the algorithm that relies on HARQ feedback after receiving the HARQ feedback. It can be seen that this solution reduces RTT while retaining HARQ feedback.

[0031] In the embodiment of the present invention, when receiving an access request from a user equipment, the base station needs to configure HARQ resources for the accessed user equipment. The HARQ resources include the number of DL HARQ processes of the PDSCH channel and HARQ feedback configuration parameters of the DL HARQ processes.

[0032] The number of DL HARQ processes can be allocated according to the capability of the connected user equipment. For example, if the user equipment supports NTN, the maximum number of DL HARQ processes allocated to the user equipment is 32; if the user equipment does not support NTN, such as R15 version, the maximum number of DL HARQ processes allocated to the user equipment is 16.

[0033] In the embodiment of the present invention, the HARQ feedback configuration parameter of the DL HARQ process includes: a feedback enabling parameter or a feedback disabling parameter. The feedback enabling parameter is used to indicate to the user equipment to enable HARQ feedback for the DL HARQ process, so as to start HARQ feedback for the DL HARQ process; the feedback disabling parameter is used to indicate to the user equipment whether to disable HARQ feedback or enable HARQ feedback.

[0034] When the feedback enabling parameter is configured for the DL HARQ process, after the base station sends DL data using the DL HARQ process, the user equipment needs to perform HARQ feedback for the DL data.

[0035] When the feedback prohibition parameter is configured for the DL HARQ process, after the base station sends DL data using the DL HARQ process, the user equipment does not need to perform HARQ feedback for the DL data.

[0036] After the user equipment accesses the base station, the base station allocates an idle HARQ pool to the user equipment according to the maximum number of DL HARQ processes that can be allocated. In the embodiment of the present invention, when determining to send feedback parameters configured for the DL HARQ process to the user equipment, the configuration method may include the following two methods:

[0037] In the first implementation, feedback enabling parameters may be configured for all DL HARQ processes in the HARQ pool;

[0038] In the second implementation manner, feedback enabling parameters may be configured for some DL HARQ processes in the HARQ pool, and feedback disabling parameters may be configured for the other DL HARQ processes.

[0039] When the first implementation is used, after the base station sends DL data using each DL HARQ process, it will receive HARQ feedback from the user equipment. Therefore, the base station side can use the HARQ feedback to perform corresponding calculations.

[0040] When the second implementation is used, after the base station sends DL data using the DL HARQ process configured with the feedback enable parameter, the base station will receive the HARQ feedback of the user equipment, but after sending DL data using the DL HARQ process configured with the feedback disable parameter, the base station will not receive the HARQ feedback of the user equipment. At this time, when the base station side performs calculations based on the HARQ feedback, the number of times DL data is sent using the DL HARQ process configured with the feedback enable parameter and the number of times DL data is sent using the DL HARQ process configured with the feedback disable parameter can be used to assist in the corresponding calculations.

[0041] When using the second implementation, in order to facilitate the algorithm that relies on HARQ feedback on the base station side to calculate more easily and accurately, when sending new DL data to the user equipment, the DL HARQ process configured with the feedback enabling parameter is preferentially selected in the idle HARQ pool for sending. In this way, the number of HARQ feedbacks received by the base station side can be increased, and the calculation accuracy of the algorithm based on HARQ feedback can be improved.

[0042] In the embodiment of the present invention, when the base station sends the feedback parameters configured for the DL HARQ process to the user equipment, the sending may be performed by means of high-layer RCC signaling.

[0043] In order to enable the user equipment to know which DL HARQ processes are enabled with HARQ feedback and which DL HARQ processes are disabled with HARQ feedback based on the high-level RCC signaling, the feedback parameter may correspond to the identifier of the DL HARQ process. In implementation, specifically, a corresponding feedback parameter may be mapped to the identifier of each DL HARQ process; or, multiple DL HARQ processes may be grouped, and a corresponding feedback parameter may be mapped to each group.

[0044] In order to reduce the number of characters occupied by the feedback parameter in the high-level RCC signaling, the feedback enable parameter and the feedback disable parameter can be distinguished by identification. For example, "1" is used to represent the feedback enable parameter, and "0" is used to represent the feedback disable parameter. In this way, the feedback parameter can be configured by occupying only 1 bit.

[0045] In the embodiment of the present invention, when the user equipment is accessed, the base station also needs to configure the maximum number of transmissions for the DLHARQ process allocated to the user equipment. The maximum number of transmissions is used to indicate whether it is necessary to retransmit the DL data sent by the DL HARQ process and the number of retransmissions. For example, if the maximum number of transmissions is configured to 1, it indicates that it is not necessary to retransmit the DL data sent by the DLHARQ process; if the maximum number of transmissions is configured to 2, it indicates that after the DL data is sent by the DL HARQ process, if a NACK feedback for the DL data is received from the user equipment for the DL data, the DL data needs to be retransmitted once.

[0046] In the embodiment of the present invention, in order to ensure that the present embodiment does not increase the RTT extra compared to the NTN system, the maximum number of transmissions configured for each DL HARQ process may be 1. After the base station uses the DL HARQ process to send DL data, since the maximum number of transmissions is configured as 1, indicating that no DL data retransmission is required, the DL HARQ process may be released immediately, so that the DL HARQ process can be used by other data.

[0047] It can be seen that by configuring the maximum number of transmissions to 1, the requirement of closing data retransmission in the NTN system can be met, and when the base station uses the DL HARQ process with HARQ feedback enabled to send DL data, although the DL HARQ process is released immediately after the DL data is sent, the user equipment will still perform HARQ feedback for the DL data, that is, the base station can receive the HARQ feedback of the user equipment. In this way, compared with the NTN system, not only is there no additional RTT, but the HARQ feedback of the user equipment can be retained, providing data basis for the algorithm on the base station side that relies on HARQ feedback.

[0048] On the user equipment side, each DL HARQ process is configured using the feedback parameters sent by the base station. If the base station configures the feedback enabling parameters for the DL HARQ process, feedback is enabled for the DL HARQ process. In this way, after receiving the DL data sent by the base station, the user equipment determines whether the DL HARQ process sending the DL data is enabled with HARQ feedback. If so, HARQ feedback is performed to the base station for the DL data. If not, no HARQ feedback is performed.

[0049] It should be noted that step 100 is executed when the base station performs HARQ configuration for the user equipment when the user equipment accesses the base station. After the user equipment completes access, step 102 may be executed multiple times.

[0050] Please refer to Figure 2 , Figure 2 In the three comparison figures, the upper figure is the normal HARQ scheduling timing (recorded as timing 1), the middle figure is the scheduling timing with HARQ feedback turned off (recorded as timing 2), and the lower figure is the scheduling timing with HARQ retransmission turned off and HARQ feedback retained in this embodiment (recorded as timing 3). Figure 2 The time slot with a single stripe background color is the downlink data transmission time slot, and the time slot with a double stripe background color is the HARQ feedback time slot. Since the scheduling of the HARQ process mainly depends on the base station side, the occupation and release of the HARQ process on the base station side is one HARQ RTT. The air interface delay is t_air, the base station processing delay is t_proc_gnb, and the UE processing delay is t_procPDS_UE and t_procUCI_UE. Assuming t_air=3tti, t_proc_gnb=4tti, t_procPDS_UE=2tti, t_procUCI_UE=1tti, then:

[0051] The HARQ RTT calculated in sequence 1 is:

[0052] HARQ RTT=2*t_air+t_proc_gnb+t_procPDS_UE+t_procUCI_UE=13TTI;

[0053] The HARQ RTT calculated in sequence 2 is:

[0054] HARQ RTT=MAX(t_proc_gnb,t_procPDS_UE)=4TTI;

[0055] The HARQ RTT calculated in sequence 3 is:

[0056] HARQ RTT=MAX(t_proc_gnb,t_procPDS_UE+t_procUCI_UE)=4TTI;

[0057] It can be seen that the delays of the HARQ RTTs of Sequence 2 and Sequence 3 are consistent and much smaller than the delay of Sequence 1. Therefore, the advantage of this embodiment is that the HARQ RTT does not increase due to the increase in delay, and at the same time the HARQ feedback result is retained, ensuring that the base station side can count the HARQ BLER.

[0058] like Figure 3 , Figure 4 As shown, an embodiment of the present invention provides a HARQ feedback device in a non-terrestrial network. The device embodiment can be implemented by software, or by hardware or a combination of software and hardware. From the hardware level, Figure 3 FIG. 1 is a hardware architecture diagram of an electronic device in which a HARQ feedback device in a non-terrestrial network provided by an embodiment of the present invention is located. Figure 3 In addition to the processor, memory, network interface, and non-volatile memory shown, the electronic device in the embodiment may also include other hardware, such as a forwarding chip responsible for processing messages, etc. Taking software implementation as an example, Figure 4 As shown, as a device in a logical sense, the CPU of the electronic device in which it is located reads the corresponding computer program in the non-volatile memory into the memory and runs it. This embodiment provides a HARQ feedback device in a non-terrestrial network, which is applied to a base station, and the device includes:

[0059] The resource configuration unit 401 is configured to send a feedback enabling parameter configured for a DL HARQ process to a user equipment, wherein the feedback enabling parameter is used to indicate that the user equipment enables HARQ feedback for the DL HARQ process; and configure a maximum number of transmission times for each DL HARQ process as 1;

[0060] The processing unit 402 is configured to release the DL HARQ process immediately after sending DL data using the DL HARQ process enabled with HARQ feedback, and receive HARQ feedback from the user equipment for the DL data after releasing the DL HARQ process.

[0061] In one embodiment of the present invention, the resource configuration unit 401 is used to configure the feedback enabling parameter for some DL HARQ processes among multiple DL HARQ processes allocated to the user equipment.

[0062] In one embodiment of the present invention, the processing unit 402 is further configured to preferentially select a DL HARQ process configured with a feedback enabling parameter in an idle HARQ pool for sending new DL data to the user equipment.

[0063] It is to be understood that the structure illustrated in the embodiment of the present invention does not constitute a specific limitation on a HARQ feedback device in an NTN. In other embodiments of the present invention, a HARQ feedback device in an NTN may include more or fewer components than those illustrated, or combine certain components, or separate certain components, or arrange the components differently. The illustrated components may be implemented in hardware, software, or a combination of software and hardware.

[0064] The information interaction, execution process and other contents between the modules in the above-mentioned device are based on the same concept as the embodiment of the method of the present invention. For the specific contents, please refer to the description in the embodiment of the method of the present invention, and no further description is given here.

[0065] An embodiment of the present invention further provides an electronic device, including a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, a HARQ feedback method in a non-terrestrial network in any embodiment of the present invention is implemented.

[0066] An embodiment of the present invention further provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the processor executes a HARQ feedback method in a non-terrestrial network in any embodiment of the present invention.

[0067] Specifically, a system or device equipped with a storage medium can be provided, on which software program code that implements the functions of any of the above-mentioned embodiments is stored, and a computer (or CPU or MPU) of the system or device can be enabled to read and execute the program code stored in the storage medium.

[0068] In this case, the program code itself read from the storage medium can realize the function of any one of the above-mentioned embodiments, and thus the program code and the storage medium storing the program code constitute a part of the present invention.

[0069] The storage medium embodiments for providing the program code include a floppy disk, a hard disk, a magneto-optical disk, an optical disk (such as CD-ROM, CD-R, CD-RW, DVD-ROM, DVD-RAM, DVD-RW, DVD+RW), a magnetic tape, a non-volatile memory card, and a ROM. Alternatively, the program code can be downloaded from a server computer by a communication network.

[0070] In addition, it should be clear that the functions of any of the above embodiments can be implemented not only by executing the program code read by the computer, but also by enabling an operating system operating on the computer to complete part or all of the actual operations based on instructions from the program code.

[0071] In addition, it can be understood that the program code read from the storage medium is written to a memory provided in an expansion board inserted into the computer or to a memory provided in an expansion module connected to the computer, and then based on the instructions of the program code, a CPU installed on the expansion board or expansion module is enabled to perform part or all of the actual operations, thereby realizing the functions of any of the above-mentioned embodiments.

[0072] It should be noted that, in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "comprise a ..." do not exclude the presence of other identical factors in the process, method, article or device including the elements.

[0073] A person of ordinary skill in the art can understand that all or part of the steps of implementing the above method embodiments can be completed by hardware related to program instructions, and the aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it executes the steps of the above method embodiments; and the aforementioned storage medium includes: ROM, RAM, magnetic disk or optical disk, etc., various media that can store program codes.

[0074] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A hybrid automatic repeat request HARQ feedback method in a non-terrestrial network, characterized in that: Applied to a base station, the method is used to retain HARQ feedback, and compared with a non-terrestrial network NTN system in which DL HARQ feedback is disabled, without increasing the round trip delay. The method includes: Sending a feedback enabling parameter configured for a DL HARQ process to a user equipment, wherein the feedback enabling parameter is used to indicate to the user equipment to enable HARQ feedback for the DL HARQ process; configuring a maximum number of transmissions for each DL HARQ process to be 1; After sending DL data using a DL HARQ process enabled with HARQ feedback, the DL HARQ process is immediately released without waiting for HARQ feedback, and after releasing the DL HARQ process, HARQ feedback from the user equipment for the DL data is received, so as to use the received HARQ feedback to provide a data basis for an algorithm that relies on the HARQ feedback.

2. The method according to claim 1, characterized in that The feedback enabling parameter is configured for some DL HARQ processes among a plurality of DL HARQ processes allocated to the user equipment.

3. The method according to claim 2, characterized in that When sending new DL data to the user equipment, a DL HARQ process configured with a feedback enabling parameter is preferentially selected in an idle HARQ pool for sending.

4. A HARQ feedback device in a non-terrestrial network, characterized in that: Applied to a base station, the device is used to retain HARQ feedback, and does not increase the round trip delay compared to a non-terrestrial network NTN system with DL HARQ feedback turned off, and the device includes: a resource configuration unit, configured to send a feedback enabling parameter configured for a DL HARQ process to a user equipment, wherein the feedback enabling parameter is used to instruct the user equipment to enable HARQ feedback for the DL HARQ process; and configure a maximum number of transmissions for each DL HARQ process as 1; A processing unit is used to release the DL HARQ process immediately without waiting for HARQ feedback after sending DL data using a DL HARQ process enabled with HARQ feedback, and receive HARQ feedback from the user equipment for the DL data after releasing the DL HARQ process, so as to use the received HARQ feedback to provide data basis for an algorithm that relies on the HARQ feedback.

5. The device according to claim 4, characterized in that The resource configuration unit is configured to configure the feedback enabling parameter for some DL HARQ processes among the multiple DL HARQ processes allocated to the user equipment.

6. The device according to claim 5, characterized in that The processing unit is further configured to preferentially select a DL HARQ process configured with a feedback enabling parameter in an idle HARQ pool for sending new DL data to the user equipment.

7. An electronic device, comprising a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the method according to any one of claims 1 to 3 is implemented.

8. A computer-readable storage medium having a computer program stored thereon, which, when executed in a computer, causes the computer to execute the method according to any one of claims 1 to 3.

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