KR102661305B1 - Method and apparatus for hybrid automatic repeat request feedback in communication system - Google Patents

Abstract

A method and apparatus for HARQ feedback in a communication system are disclosed. The operation method of the terminal is to receive first configuration information of the first HARQ process group and second configuration information of the second HARQ process group from the base station, and configure RV and HARQ processes including first information indicating the HARQ process group. An HPN including second information indicating a number and control information including resource allocation information are received from the base station, data is received from the base station based on the resource allocation information, and included in the control information. and determining whether to transmit HARQ feedback for the data according to the first information.

Description

Method and apparatus for HARQ feedback in communication system {METHOD AND APPARATUS FOR HYBRID AUTOMATIC REPEAT REQUEST FEEDBACK IN COMMUNICATION SYSTEM}

The present invention relates to HARQ (hybrid automatic repeat request) feedback technology in a communication system, and more specifically, to independent feedback technology for each HARQ process.

To handle the rapid increase in wireless data, a higher frequency band (e.g., a frequency band above 6 GHz) than the frequency band of long term evolution (LTE) (e.g., a frequency band below 6 GHz) (e.g., a frequency band below 6 GHz) A communication network using (e.g., a new radio (NR) communication network) is being considered. The NR communication network can support not only frequency bands below 6 GHz but also frequency bands above 6 GHz, and can support a variety of communication services and scenarios compared to LTE communication networks. For example, usage scenarios of the NR communication network may include enhanced Mobile BroadBand (eMBB), Ultra Reliable Low Latency Communication (URLLC), massive Machine Type Communication (mMTC), etc.

The NR communication network can provide communication services to terminals located on the ground (terrestrial). Recently, the demand for communication services for airplanes, drones, satellites, etc. located not only on the ground but also in non-terrestrial areas is increasing, and for this purpose, a non-terrestrial network (NTN) ) technologies are being discussed. Non-terrestrial networks can be implemented based on NR technology. For example, in a non-terrestrial network, communication between a satellite and a terrestrial communication node or a non-terrestrial communication node (eg, an airplane, a drone, etc.) may be performed based on NR technology. In non-terrestrial networks, satellites can perform the function of base stations in NR communication networks.

On the other hand, when the communication distance between the base station and the terminal increases, and the round trip time (RTT) increases significantly, the limited number of HARQ processes and the PDSCH-to-HARQ_feedback timing indicator allow for smooth operation. There is a problem that it is difficult to expect operation.

The purpose of the present invention to solve the above problems is to provide a method and device for feedback supported/unsupported HARQ feedback in a communication system.

A method for HARQ feedback by a terminal according to the first embodiment of the present invention to achieve the above object includes the first configuration information of the first HARQ process group and the second configuration information of the second HARQ process group. RV, which receives a layer message from a base station and includes first information indicating one HARQ process group used for communication between the terminal and the base station among the first HARQ process group and the second HARQ process group, Receive control information including an HPN including second information indicating the number of a HARQ process belonging to the one HARQ process group indicated by the first information, and resource allocation information from the base station, and receiving data from the base station based on the data, and determining whether to transmit HARQ feedback for the data according to the first information included in the control information, wherein the first HARQ process group receives the HARQ feedback Includes a plurality of Type 1-HARQ processes that support, and the second HARQ process group includes a plurality of Type 2-HARQ processes that do not support the HARQ feedback.

Here, the first configuration information may include information about the first HARQ process group to which the plurality of Type 1-HARQ processes belong and HARQ process numbers set for the plurality of Type 1-HARQ processes.

Here, the second configuration information may include information about the second HARQ process group to which the plurality of Type 2-HARQ processes belong and HARQ process numbers set for the plurality of Type 2-HARQ processes.

Here, when the first information included in the RV indicates the first HARQ process group, the HPN may further include information indicating an extension value of PDSCH-to-HARQ_feedback timing.

Here, when the second information included in the HPN indicates the number of one of the plurality of type 2-HARQ processes belonging to the second HARQ process group, the control information includes DAI and PDSCH-to-HARQ_ It further includes a feedback timing indicator, and the DAI and the PDSCH-to-HARQ_feedback timing indicator can be used as a HARQ process extension value.

Here, the operating method of the terminal includes performing a transmission operation of the HARQ feedback to the base station according to information indicated by the first information, wherein the first information indicates the first HARQ process group. In this case, the transmission operation of the HARQ feedback may be performed, and if the first information indicates the second HARQ process group, the transmission operation of the HARQ feedback may not be performed.

The method for HARQ feedback by a base station according to the second embodiment of the present invention to achieve the above object includes a first HARQ process group including a plurality of type 1-HARQ processes and a plurality of type 2-HARQ processes. Establishes a second HARQ process group, transmits an upper layer message including first configuration information of the first HARQ process group and second configuration information of the second HARQ process group to the terminal, and configures the first HARQ process RV containing first information indicating one HARQ process group used for communication between the terminal and the base station among the group and the second HARQ process group, the one HARQ process group indicated by the first information Transmitting control information including an HPN including second information indicating the number of the HARQ process to which it belongs and resource allocation information to the terminal, and transmitting data to the terminal based on the control information; , the plurality of Type 1-HARQ processes includes a plurality of HARQ processes that support HARQ feedback, and the plurality of Type 2-HARQ processes include a plurality of HARQ processes that do not support HARQ feedback.

Here, the first configuration information may include information about the first HARQ process group to which the plurality of Type 1-HARQ processes belong and HARQ process numbers set for the plurality of Type 1-HARQ processes.

Here, the second configuration information may include information about the second HARQ process group to which the plurality of Type 2-HARQ processes belong and HARQ process numbers set for the plurality of Type 2-HARQ processes.

Here, when the first information included in the RV indicates the first HARQ process group, the HPN may further include information indicating an extension value of PDSCH-to-HARQ_feedback timing.

Here, when the second information included in the HPN indicates the number of one of the plurality of type 2-HARQ processes belonging to the second HARQ process group, the control information includes DAI and PDSCH-to-HARQ_ It further includes a feedback timing indicator, and the DAI and the PDSCH-to-HARQ_feedback timing indicator can be used as a HARQ process extension value.

Here, the operating method of the base station includes performing an operation of receiving HARQ feedback for the data from the terminal according to information indicated by the first information, and the first information is transmitted to the first HARQ process group. If indicated, the HARQ feedback reception operation may be performed, and if the first information indicates the second HARQ process group, the HARQ feedback reception operation may not be performed.

A terminal according to a third embodiment of the present invention for achieving the above object includes a processor, a memory in electronic communication with the processor, and instructions stored in the memory, when the instructions are executed by the processor. , the commands are such that the terminal receives a higher layer message including first configuration information of the first HARQ process group and second configuration information of the second HARQ process group from the base station, and the first HARQ process group and the second 2 RV including first information indicating one HARQ process group used for communication between the terminal and the base station among the HARQ process groups, the HARQ process belonging to the one HARQ process group indicated by the first information An HPN including second information indicating a number and control information including resource allocation information are received from the base station, data is received from the base station based on the resource allocation information, and included in the control information. Determines whether to transmit HARQ feedback for the data according to the first information, and the first HARQ process group includes a plurality of type 1-HARQ processes supporting the HARQ feedback, and the second HARQ process group Operates to cause the inclusion of a plurality of Type 2-HARQ processes that do not support the HARQ feedback.

Here, the first configuration information may operate to cause the first HARQ process group to which the plurality of Type 1-HARQ processes belong and information about the HARQ process number set for the plurality of Type 1-HARQ processes. You can.

Here, the second configuration information may operate to cause the second HARQ process group to which the plurality of Type 2-HARQ processes belong and information about the HARQ process number set for the plurality of Type 2-HARQ processes. You can.

Here, when the first information included in the RV indicates the first HARQ process group, the HPN may operate to cause the HPN to further include information indicating an extension value of PDSCH-to-HARQ_feedback timing. You can.

Here, when the second information included in the HPN indicates the number of one of the plurality of type 2-HARQ processes belonging to the second HARQ process group, the control information includes DAI and PDSCH-to-HARQ_ It further includes a feedback timing indicator, and is operable to cause the DAI and the PDSCH-to-HARQ_feedback timing indicator to be used as a HARQ process extension value.

Here, the commands cause the terminal to transmit the HARQ feedback to the base station according to information indicated by the first information, and when the first information indicates the first HARQ process group, the HARQ The transmission operation of feedback may be performed, and when the first information indicates the second HARQ process group, the operation may be operated to cause the transmission operation of HARQ feedback not to be performed.

According to the present invention, in a wireless communication system with a long RTT, the base station can divide HARQ processes into feedback-supported or non-supported HARQ process groups so as to smoothly perform the HARQ function. Through this, the base station can expand the PDSCH-to-HARQ_feedback timing or the number of HARQ processes. Therefore, by improving spectral efficiency in a wireless communication system with a long RTT, the performance of the communication system can be improved.

1 is a conceptual diagram illustrating an embodiment of a communication system.
Figure 2 is a block diagram showing an embodiment of a communication node constituting a communication system.
FIG. 3A is a conceptual diagram illustrating a first embodiment of HARQ processes for supporting/not supporting feedback in a communication system.
Figure 3b is a conceptual diagram showing a second embodiment of HARQ processes for supporting/not supporting feedback in a communication system.
Figure 4 is a flowchart showing a first embodiment of a feedback method in a HARQ process for feedback support in a communication system.
Figure 5 is a conceptual diagram showing a resource allocation method for the HPN field in a communication system.
Figure 6 is a flowchart showing a first embodiment of a feedback method in a HARQ process for non-feedback support in a communication system.
Figure 7 is a conceptual diagram showing a method of expanding the HARQ process in a communication system.

Since the present invention can make various changes and have various embodiments, specific embodiments will be illustrated in the drawings and described in detail. However, this is not intended to limit the present invention to specific embodiments, and should be understood to include all changes, equivalents, and substitutes included in the spirit and technical scope of the present invention.

Terms such as first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another. For example, a first component may be named a second component without departing from the scope of the present invention, and similarly, the second component may also be named a first component. The term and/or includes any of a plurality of related stated items or a combination of a plurality of related stated items.

In embodiments of the present application, “at least one of A and B” may mean “at least one of A or B” or “at least one of combinations of one or more of A and B.” Additionally, in embodiments of the present application, “one or more of A and B” may mean “one or more of A or B” or “one or more of combinations of one or more of A and B.”

When a component is said to be "connected" or "connected" to another component, it is understood that it may be directly connected to or connected to the other component, but that other components may exist in between. It should be. On the other hand, when it is mentioned that a component is “directly connected” or “directly connected” to another component, it should be understood that there are no other components in between.

The terms used in this application are only used to describe specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, terms such as “comprise” or “have” are intended to designate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but are not intended to indicate the presence of one or more other features. It should be understood that this does not exclude in advance the possibility of the existence or addition of elements, numbers, steps, operations, components, parts, or combinations thereof.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by a person of ordinary skill in the technical field to which the present invention pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related technology, and should not be interpreted in an ideal or excessively formal sense unless explicitly defined in the present application. No.

Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the attached drawings. In order to facilitate overall understanding when describing the present invention, the same reference numerals are used for the same components in the drawings, and duplicate descriptions for the same components are omitted.

A communication system to which embodiments according to the present invention are applied will be described. The communication systems to which the embodiments according to the present invention are applied are not limited to those described below, and the embodiments according to the present invention can be applied to various communication systems. Here, communication system may be used in the same sense as communication network.

1 is a conceptual diagram showing a first embodiment of a communication system.

Referring to FIG. 1, the communication system 100 includes a plurality of communication nodes 110-1, 110-2, 110-3, 120-1, 120-2, 130-1, 130-2, 130-3, 130-4, 130-5, 130-6). A plurality of communication nodes are 4G communication (e.g., long term evolution (LTE), LTE-A (advanced)), 5G communication (e.g., new radio (NR)) specified in the 3rd generation partnership project (3GPP) standard. ), etc. can be supported. 4G communications can be performed in frequency bands below 6 GHz, and 5G communications can be performed in frequency bands above 6 GHz as well as below 6 GHz.

For example, for 4G communication and 5G communication, a plurality of communication nodes may use a communication protocol based on code division multiple access (CDMA), a communication protocol based on wideband CDMA (WCDMA), a communication protocol based on time division multiple access (TDMA), Communication protocol based on FDMA (frequency division multiple access), communication protocol based on OFDM (orthogonal frequency division multiplexing), communication protocol based on Filtered OFDM, communication protocol based on CP (cyclic prefix)-OFDM, DFT-s-OFDM (discrete Fourier transform-spread-OFDM)-based communication protocol, OFDMA (orthogonal frequency division multiple access)-based communication protocol, SC (single carrier)-FDMA-based communication protocol, NOMA (Non-orthogonal Multiple Access), GFDM (generalized frequency) division multiplexing)-based communication protocols, FBMC (filter bank multi-carrier)-based communication protocols, UFMC (universal filtered multi-carrier)-based communication protocols, and SDMA (Space Division Multiple Access)-based communication protocols. .

Additionally, the communication system 100 may further include a core network. If the communication system 100 supports 4G communication, the core network may include a serving-gateway (S-GW), a packet data network (PDN)-gateway (P-GW), a mobility management entity (MME), etc. there is. When the communication system 100 supports 5G communication, the core network may include a user plane function (UPF), a session management function (SMF), and an access and mobility management function (AMF).

Meanwhile, a plurality of communication nodes (110-1, 110-2, 110-3, 120-1, 120-2, 130-1, 130-2, 130-3, 130-) constituting the communication system 100 4, 130-5, 130-6) Each can have the following structure.

Figure 2 is a block diagram showing a first embodiment of a communication node constituting a communication system.

Referring to FIG. 2, the communication node 200 may include at least one processor 210, a memory 220, and a transmitting and receiving device 230 that is connected to a network and performs communication. Additionally, the communication node 200 may further include an input interface device 240, an output interface device 250, a storage device 260, etc. Each component included in the communication node 200 is connected by a bus 270 and can communicate with each other.

However, each component included in the communication node 200 may be connected through an individual interface or individual bus centered on the processor 210, rather than the common bus 270. For example, the processor 210 may be connected to at least one of the memory 220, the transmission/reception device 230, the input interface device 240, the output interface device 250, and the storage device 260 through a dedicated interface. .

The processor 210 may execute a program command stored in at least one of the memory 220 and the storage device 260. The processor 210 may refer to a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor on which methods according to embodiments of the present invention are performed. Each of the memory 220 and the storage device 260 may be comprised of at least one of a volatile storage medium and a non-volatile storage medium. For example, the memory 220 may be comprised of at least one of read only memory (ROM) and random access memory (RAM).

Referring again to FIG. 1, the communication system 100 includes a plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) and a plurality of terminals (130- 1, 130-2, 130-3, 130-4, 130-5, 130-6). Base stations (110-1, 110-2, 110-3, 120-1, 120-2) and terminals (130-1, 130-2, 130-3, 130-4, 130-5, 130-6) The communication system 100 that includes may be referred to as an “access network.” Each of the first base station 110-1, the second base station 110-2, and the third base station 110-3 may form a macro cell. Each of the fourth base station 120-1 and the fifth base station 120-2 may form a small cell. The fourth base station 120-1, the third terminal 130-3, and the fourth terminal 130-4 may belong to the cell coverage of the first base station 110-1. The second terminal 130-2, the fourth terminal 130-4, and the fifth terminal 130-5 may belong to the cell coverage of the second base station 110-2. The fifth base station 120-2, the fourth terminal 130-4, the fifth terminal 130-5, and the sixth terminal 130-6 may belong to the cell coverage of the third base station 110-3. there is. The first terminal 130-1 may belong to the cell coverage of the fourth base station 120-1. The sixth terminal 130-6 may belong to the cell coverage of the fifth base station 120-2.

Here, each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 includes a NodeB, an evolved NodeB, a base transceiver station (BTS), Radio base station, radio transceiver, access point, access node, road side unit (RSU), radio remote head (RRH), transmission point (TP), TRP ( transmission and reception ooint), eNB, gNB, etc.

A plurality of terminals (130-1, 130-2, 130-3, 130-4, 130-5, and 130-6) each include a user equipment (UE), a terminal, an access terminal, and a mobile device. Terminal, station, subscriber station, mobile station, portable subscriber station, node, device, IoT (Internet of Thing) It may be referred to as a device, a mounted device (mounted module/device/terminal or on board device/terminal, etc.), etc.

Next, HARQ (hybrid automatic repeat request) feedback methods in a communication system will be described. Even when a method (e.g., transmission or reception of a signal) performed in a first communication node (or transmission node) among communication nodes is described, the corresponding second communication node (or reception node) is the first communication node. A method corresponding to the method performed in (e.g., receiving or transmitting a signal) may be performed. That is, when the operation of the terminal is described, the corresponding base station can perform the operation corresponding to the operation of the terminal. Conversely, when the operation of the base station is described, the corresponding terminal can perform the operation corresponding to the operation of the base station.

Feedback transmission and reception methods can be used to improve reliability and efficiency in communication systems. When a transmitting node in a communication system transmits a signal to a receiving node, the receiving node can transmit feedback indicating information on whether the signal transmitted from the transmitting node has been properly received (i.e., whether the received signal has been properly decoded) to the transmitting node. there is. For example, in one embodiment of the communication system, it may be a HARQ feedback method.

When the HARQ feedback method is used, if the receiving node succeeds in decoding the first signal (e.g., data) received from the transmitting node, HARQ feedback indicating that the first signal has been properly decoded can be transmitted to the transmitting node. . Here, HARQ feedback indicating that the first signal was normally decoded may correspond to ACK. Meanwhile, when the receiving node fails to decode the first signal received from the transmitting node, it may transmit HARQ feedback indicating that the first signal was not properly decoded to the transmitting node. Here, HARQ feedback indicating that the first signal was not decoded properly may correspond to NACK. When the transmitting node receives the NACK from the receiving node, it may determine that the first signal was not properly received by the receiving node, and may perform a retransmission operation for the first signal.

In one embodiment of the communication system, the receiving node may determine whether decoding is successful in units of TB (transport block). For example, if the receiving node fails to decode or detects an error during the decoding process for the TB constituting the first signal transmitted from the transmitting node, it may transmit a NACK for the corresponding TB. However, this is only an example for convenience of explanation, and embodiments of the present invention are not limited thereto. For example, the receiving node may determine whether decoding is successful on a CB (code block) basis for the first signal received from the transmitting node. Alternatively, the receiving node may determine whether decoding is successful on a CBG (code block group) basis for the first signal received from the transmitting node. Here, CBG is a group consisting of at least one CB, which may be smaller than TB and larger than or equal to CB. If the receiving node fails to decode or detects an error during the decoding process for some of the CBs constituting the first signal received from the transmitting node, it may transmit a NACK for the corresponding CBs. If the receiving node fails to decode or detects an error during the decoding process for some of the CBGs constituting the first signal received from the transmitting node, it may transmit a NACK for the corresponding CBG.

In one embodiment of a communication system, an upper node (eg, base station) may perform downlink transmission to a lower node (eg, terminal). The lower node can transmit HARQ feedback to the upper node as feedback on downlink transmission from the upper node. Hereinafter, an embodiment of a method for transmitting and receiving HARQ feedback will be described using as an example a situation in which a terminal performs HARQ feedback for downlink data transmission performed by a base station to the terminal. However, this is only an example for convenience of explanation, and embodiments of the present invention are not limited thereto.

In one embodiment of the feedback transmission and reception method, the base station may transmit downlink data to the terminal through a physical downlink shared channel (PDSCH). The terminal can transmit HARQ feedback for downlink data received from the base station to the base station through a physical uplink control channel (PUCCH). Alternatively, the terminal may transmit HARQ feedback for downlink data received from the base station to the base station through a physical uplink shared channel (PUSCH). If the terminal succeeds in decoding the downlink data received from the base station, it can transmit an ACK to the base station. Meanwhile, if the terminal fails to decode downlink data received from the base station, it can transmit a NACK to the base station. When the base station receives a NACK from the terminal, it can determine that the downlink data transmitted to the terminal was not transmitted properly and can retransmit the downlink data.

Before transmitting downlink data to the terminal through the PDSCH, the base station may transmit downlink control information (DCI) to the terminal through a physical downlink control channel (PDCCH). The DCI that the base station transmits to the terminal prior to downlink data can be configured based on any one of the DCI formats defined according to the 3GPP communication standard. For example, the DCI that the base station transmits to the terminal prior to downlink data may be configured based on DCI formats 1_0, 1_1, 1_2, etc. Alternatively, the DCI that the base station transmits to the terminal prior to downlink data may have a separately defined structure to support an embodiment of the feedback transmission and reception method. DCI 1_0, which the base station transmits to the terminal prior to downlink data, may be configured to include some or all of the fields shown in Table 1. Additionally, DCI 1_1 may be configured to include some or all of the fields shown in Table 2.

In Tables 1 and 2, the “ Identifier for DCI formats ” field may indicate the DCI format. The “FDRA ( Frequency domain resource assignment )” field may indicate resource allocation information in the frequency domain where downlink data is transmitted. The “TDRA ( Time domain resource assignment )” field may indicate resource allocation information in the time domain in which downlink data is transmitted. The “MCS ( Modulation and coding scheme )” field may indicate information related to the way downlink data is modulated and encoded. The “NDI ( New data indicator )” field may indicate whether downlink data is initially transmitted or retransmitted. The “HPN ( HARQ process number )” field may indicate the number of at least one HARQ process. The “DAI ( Downlink assignment index )” field may indicate the number of PDSCHs transmitted in one slot. The “PRI ( PUCCH resource indicator )” field may indicate information on the PUCCH resource to be used in the HARQ response. The " PDSCH-to-HARQ_feedback timing indicator " field may indicate information such as the time interval or number of slots from when the PDSCH is transmitted until the HARQ response is transmitted.

The DCI that the base station transmits to the terminal prior to downlink data may be configured to include at least some of one or more fields shown in Table 1. Additionally, the DCI that the base station transmits to the terminal prior to downlink data may be configured to include at least some of one or more fields shown in Table 2. Each of the DCI fields that the base station transmits to the terminal prior to downlink data may be configured to have a size that is the same as or different from the size shown in Table 1. Additionally, each of the DCI fields that the base station transmits to the terminal prior to downlink data may be configured to have a size that is the same as or different from the size shown in Table 2. The types of fields included in the DCI that the base station transmits to the terminal prior to downlink data may be determined differently depending on the format of the DCI. However, this is only an example for convenience of explanation, and embodiments of the present invention are not limited thereto.

FIG. 3A is a conceptual diagram showing a first embodiment of HARQ processes for supporting/not supporting feedback in a communication system, and FIG. 3B is a conceptual diagram showing a second embodiment of HARQ processes for supporting/not supporting feedback in a communication system.

Referring to FIGS. 3A and 3B, the base station can expand the number of HARQ processes and the PDSCH-to-HARQ_feedback timing field, and the transmission and reception method to support this may vary depending on the HARQ process group.

The HARQ process for supporting HARQ feedback can be referred to as a type 1-HARQ process. Additionally, a HARQ process that does not support HARQ feedback and does not support HARQ feedback may be referred to as a type 2-HARQ process. The base station can be divided into a feedback-supporting HARQ process group including a plurality of Type 1-HARQ processes and a non-feedback HARQ process group including a plurality of Type 2-HARQ processes.

[How to continuously configure HARQ processes for feedback support/non-support]

Referring again to FIG. 3A, the base station may configure M HARQ processes (i.e., HARQ processes #0 to M-1) among the N HARQ processes as HARQ processes, and set the remaining N-M HARQ processes (i.e., HARQ processes #M to #N-1) can be set as HARQ processes that do not support feedback. M HARQ processes that are HARQ processes for feedback support may have consecutive numbers, and N-M HARQ processes that are HARQ processes that do not support feedback may have consecutive numbers.

In this way, when M HARQ processes for feedback support and N-M HARQ processes for non-feedback support belonging to two HARQ process groups have consecutive numbers, the base station determines the number of HARQ processes for feedback support M and the point at which the M value is applied through the system. It can be transmitted to the terminal through at least one of information, upper layer message, media access control (MAC) control element (CE), or DCI.

In addition, the base station can inform the terminal of the point in time when the M value is applied to the terminal as the number of slots (or subframes) after the terminal receives at least one of the corresponding system information, upper layer message, MAC CE, or DCI. The number of slots may be a slot offset. The terminal may receive from the base station the number M of HARQ processes for feedback support and the point in time at which the M value is applied through at least one of system information, a higher layer message, MAC CE, or DCI.

In the above-described method, the base station can change the M value according to the quality-of-service (QoS) of the terminal, and can also set the M value to the number of HARQ processes for non-feedback support.

[How to discontinuously configure HARQ processes for feedback support/non-support]

Referring again to FIG. 3B, the base station may configure M HARQ processes (i.e., HARQ processes # n ₀ to # n _M-1 ) among the N HARQ processes as HARQ processes for feedback support, and the remaining NM HARQ processes. Processes (i.e., HARQ processes # n _M to # n _N-1 ) can be set as HARQ processes for non-feedback support. M HARQ processes, which are HARQ processes for feedback support, may have non-consecutive numbers, and NM HARQ processes, which are HARQ processes for non-feedback support, may have non-consecutive numbers.

In this way, when M HARQ processes for feedback support and NM HARQ processes for non-feedback support belonging to two HARQ process groups have non-consecutive numbers, the base station uses n ₀ , n ₁ , ??, which are the numbers of HARQ processes for feedback support. , n _M-1 and the time point at which the corresponding number is applied can be transmitted to the terminal through at least one of system information, upper layer message, MAC CE, or DCI.

The base station may inform the terminal of the time at which the corresponding HARQ process is applied by the number of slots (or subframes) after receiving at least one of the corresponding system information, upper layer message, MAC CE, or DCI. The number of slots may be a slot offset. The terminal can receive n ₀ , n ₁ , ??, n _M-1 , which are the numbers of the HARQ process for feedback support, from the base station and the time when the number is applied through at least one of system information, upper layer message, MAC CE or DCI. You can.

The base station can define n ₀ , n ₁ ,??, n _M-1 as specific settings as shown in Table 3 below. Therefore, the base station can reduce the amount of information transmitted to the terminal through at least one of system information, upper layer messages, MAC CE, or DCI.

In the method of configuring the above-described HARQ processes discontinuously, the base station can expand the configuration of Table 3, and the M value and n ₀ , n ₁ ,??, n _M-1 are the QoS (quality-of-) of the terminal. It can be changed depending on the service. Additionally, for smooth HARQ operation in a wireless communication system with a long RTT, the base station can set the number of HARQ processes for feedback support to be smaller than the number of HARQ processes for non-feedback support.

[Method for distinguishing HARQ process groups for feedback support/non-support]

The base station can configure the RV field included in DCI with a total of 2 bits, which can indicate four retransmission data versions. However, the base station may reduce the RV field to indicate the retransmission data version because the number of retransmissions may be very limited in wireless communication systems with long RTTs. Therefore, the base station can use 1 of the 2 bits of the RV field to distinguish between a HARQ process group for feedback support and a HARQ process group for non-feedback support instead of indicating the retransmission data version.

The base station can use 1 least significant bit (LSB) of the 2 bits of the RV field to distinguish HARQ process groups. The base station may set 1 LSB to a first value (e.g., 0) to indicate that it is a HARQ process group for non-feedback support, and set 1 LSB to a second value (e.g., 0) to indicate that it is a HARQ process group for feedback support. It can be set to 1). The base station may transmit DCI including the RV field to the terminal. The terminal can receive a DCI including the RV field from the base station, and can interpret the value of the HPN field included in the DCI in conjunction with the corresponding RV field. That is, when 1 LSB is 0, the HPN field may indicate a HARQ process number for non-feedback support, and when 1 LSB is 1, the HPN field may indicate a HARQ process number for feedback support. Therefore, 1 MSB (most significant bit) of the 2 bits of the RV field may indicate the conventional retransmission data version.

In the above-described method, the base station may be set so that when 1 LSB is 0, it means a HARQ process group for feedback support, and when 1 LSB is 1, it means a HARQ process group without feedback support.

In the above-described method, the base station may use 1 MSB of the 2 bits of the RV field to distinguish HARQ process groups, and 1 LSB may be used to indicate the conventional retransmission data version.

[Extension method of PDSCH-to-HARQ_feedback timing for smooth operation of HARQ process for feedback support]

Figure 4 is a flowchart showing a first embodiment of a feedback method in a HARQ process for feedback support in a communication system.

Referring to FIG. 4, the base station uses a method of continuously setting up the HARQ process for feedback support described above (e.g., the method shown in FIG. 3a) or a method of discontinuously setting it (e.g., the method shown in FIG. 3b). ), the HARQ process group and HARQ process number can be set (S401). Additionally, the base station may transmit information including the HARQ process group and HARQ process number of each of a total of N HARQ processes to the terminal through at least one of system information, upper layer message, MAC CE, or DCI (S402). The terminal may receive information including the HARQ process group and HARQ process number of each of a total of N HARQ processes from the base station through at least one of system information, upper layer message, MAC CE, or DCI.

The base station can generate DCI for scheduling downlink data (S403). DCI may include resource allocation information of downlink data, RV field, HPN field, etc. In the case of the HARQ process for feedback support, the base station can set the fields included in DCI as follows. The base station applies the method for distinguishing between the HARQ process groups for feedback support and those not for support of feedback, and sets 1 LSB of the RV field included in the control information to a second value (e.g., 1) to indicate the HARQ process group for feedback support. It can be set, and some bits of the HPN field can be used as a HARQ process indicator for feedback support as follows.

Figure 5 is a conceptual diagram showing a resource allocation method for the HPN field in a communication system.

Referring to FIG. 5, the HPN field may consist of a total of 4 bits and may represent a total of 16 HARQ process numbers. In the case of a HARQ process group for feedback support, the corresponding HARQ process number may be interpreted differently depending on the number of HARQ processes for feedback support as follows.

As an embodiment of the resource allocation method of the HPN field for feedback support, when there are two HARQ processes for feedback support, the base station can use 1 LSB of the HPN field as a HARQ process indicator for feedback support. The HARQ process indicator for feedback support can indicate the first HARQ process number in the HARQ process group for feedback support when 1 LSB is 0, and can indicate the second HARQ process number in the HARQ process group for feedback support when 1 LSB is 1. there is. The base station can use the 3 MSB of the HPN field to indicate expansion of PDSCH-to-HARQ_feedback timing , various target block error rates (BLER), and/or MCS.

In another embodiment, when there are four HARQ processes for feedback support, the base station can use 2 LSB of the 4-bit HPN field as a HARQ process indicator for feedback support. The HARQ process indicator for feedback support may indicate the first HARQ process number in the HARQ process group for feedback support when 2 LSB is 00, and may indicate the second HARQ process number in the HARQ process group for feedback support when 2 LSB is 01. When 2 LSB is 10, the third HARQ process number can be indicated in the HARQ process group for feedback support, and when 2 LSB is 11, the fourth HARQ process number can be indicated in the HARQ process group for feedback support. The base station can use 2 MSB of the HPN field to indicate expansion of PDSCH-to-HARQ_feedback timing and various target BLER or MCS.

Like the method described above, the base station can use some bits of the HPN field as the corresponding HARQ process indicator. And the terminal can know the number of bits used as a HARQ process indicator through the number of HARQ processes.

In the above-described method, the base station can use the remaining bits of the HPN field (i.e., 3 MSB in the first embodiment, 2 MSB in the second embodiment) as a timing value in slot units for expansion of PDSCH-to-HARQ_feedback timing. there is. In other words, when the base station uses 2 MSB as an extension of the PDSCH-to-HARQ_feedback timing , the 2 MSB value is set to mean 8 slots when the value is 00, 12 slots when it is 01, 16 slots when it is 10, and 20 slots when it is 11. can be used, and the corresponding value can be used in addition to the conventional PDSCH-to-HARQ_feedback timing value (S405).

The base station may transmit a set of feedback timing extension values according to the MSB value to the terminal along with the above-described HARQ process information through at least one of system information, upper layer message, MAC CE, or DCI, and as described above, the set is feedback It may be defined differently depending on the number of supporting HARQ processes. The base station can use the remaining bits in the HPN field to indicate various target BLERs or MCSs in addition to extending the PDSCH-to-HARQ_feedback timing . In the above-described method, the base station can change the LSB to be used as a HARQ process indicator for feedback support into MSB.

The base station may transmit DCI including the RV field and HPN field set as described above to the terminal (S404). The terminal can receive DCI including the RV field and HPN field set by the base station from the base station. The base station can transmit downlink data to the terminal through resources allocated according to resource allocation information included in the DCI (S405). The terminal can receive downlink data from the base station. Additionally, if information included in the DCI received from the base station indicates a HARQ process for feedback support, the terminal may transmit HARQ feedback for downlink data to the base station. The base station can receive HARQ feedback for downlink data from the terminal (S406).

[HARQ process extension method for HARQ process without feedback]

Figure 6 is a flowchart showing a first embodiment of a feedback method in a HARQ process for non-feedback support in a communication system.

Referring to FIG. 6, the base station uses a method of continuously setting the HARQ process for feedback support described above (e.g., the method shown in FIG. 3A) or a method of discontinuously setting it (e.g., the method shown in FIG. 3b). ), the HARQ process group and HARQ process number can be set (S601). Additionally, the base station may transmit information including the HARQ process group and HARQ process number of each of a total of N HARQ processes to the terminal through at least one of system information, upper layer message, MAC CE, or DCI (S602). The terminal may receive information including the HARQ process group and HARQ process number of each of a total of N HARQ processes from the base station through at least one of system information, upper layer message, MAC CE, or DCI.

The base station can generate DCI for scheduling downlink data (S603). DCI may include resource allocation information of downlink data, RV field, HPN field, DAI field, PDSCH-to-HARQ_feedback timing indicator field, etc. In the case of a HARQ process that does not support feedback, the base station can set the fields included in DCI as follows. The base station applies the method for distinguishing between the HARQ process groups for supporting feedback and those not supporting feedback, and sets 1 LSB of the RV field included in the control information to a first value (for example, 0) to indicate the HARQ process group for not supporting feedback. It can be set to . Additionally, the base station can use a total of 4 bits of the HPN field as a HARQ process indicator for non-feedback support.

Figure 7 is a conceptual diagram showing a method for expanding the HARQ process in a communication system.

Referring to FIG. 7, in the case of a HARQ process without feedback support, the terminal may not transmit HARQ feedback for downlink data to the base station. Therefore, the base station may not use the DAI field and the PDSCH-to-HARQ_feedback timing indicator field included in the DCI for HARQ feedback, so the base station may use the DAI field and the PDSCH-to-HARQ_feedback timing indicator for other purposes. If the number of HARQ processes for non-feedback support is more than 16, the base station can use the DAI field consisting of 2 bits to expand the number of HARQ processes. Alternatively, the base station can use the DAI field to indicate various target BLER or MCS. The base station may also use the PDSCH-to-HARQ_feedback timing indicator field consisting of 3 bits for the same purpose as described above.

The base station may transmit DCI including the RV field, HPN field, DAI field, and PDSCH-to-HARQ_feedback timing indicator field set as described above to the terminal (S604). The terminal can receive DCI from the base station including the RV field, HPN field, DAI field, and PDSCH-to-HARQ_feedback timing indicator field set by the base station. The base station can transmit downlink data to the terminal through resources allocated according to the resource allocation information included in the DCI (S605). The terminal can receive downlink data from the base station. Additionally, if information included in the DCI received from the base station indicates a HARQ process for not supporting feedback, the terminal may not transmit HARQ feedback for downlink data to the base station.

Methods according to the present invention may be implemented in the form of program instructions that can be executed through various computer means and recorded on a computer-readable medium. Computer-readable media may include program instructions, data files, data structures, etc., singly or in combination. Program instructions recorded on a computer-readable medium may be specially designed and constructed for the present invention or may be known and usable by those skilled in the computer software art.

Examples of computer-readable media include hardware devices specially configured to store and execute program instructions, such as ROM, RAM, flash memory, etc. Examples of program instructions include machine language code, such as that produced by a compiler, as well as high-level language code that can be executed by a configured computer using an interpreter, etc. The above-described hardware device may be configured to operate with at least one software module to perform the operations of the present invention, and vice versa.

Although the description has been made with reference to the above examples, those skilled in the art will understand that various modifications and changes can be made to the present invention without departing from the spirit and scope of the present invention as set forth in the claims below. You will be able to.

Claims (18)

As a method of operating a terminal in a communication system,
Receiving from a base station an upper layer message including first configuration information of a first hybrid automatic repeat request (HARQ) process group and second configuration information of a second HARQ process group;
RV (Redundancy Version) field including first information indicating one HARQ process group used for communication between the terminal and the base station among the first HARQ process group and the second HARQ process group, the first information Receiving from the base station a HARQ Process Number (HPN) field including second information indicating the number of the HARQ process belonging to the one HARQ process group indicated by and control information including resource allocation information;
Receiving data from the base station based on the resource allocation information; and
It includes determining whether to transmit HARQ feedback for the data according to the first information included in the control information,
The first HARQ process group includes a plurality of type 1-HARQ processes that support the HARQ feedback, and the second HARQ process group includes a plurality of type 2-HARQ processes that do not support the HARQ feedback. And, when the first information included in the RV field indicates the first HARQ process group, the HPN field is PDSCH (Physical Downlink Shared Channel)-to-HARQ_feedback timing (PDSCH-to-HARQ_feedback timing) A method of operating a terminal, further including information indicating the extended value of . In claim 1,
The first configuration information includes information about the first HARQ process group to which the plurality of Type 1-HARQ processes belong and HARQ process numbers set for the plurality of Type 1-HARQ processes. In claim 1,
The second configuration information includes information about the second HARQ process group to which the plurality of Type 2-HARQ processes belong and HARQ process numbers set for the plurality of Type 2-HARQ processes. delete In claim 1,
When the second information included in the HPN field indicates the number of one of the plurality of type 2-HARQ processes belonging to the second HARQ process group, the control information includes downlink assignment index (DAI) and PDSCH- It further includes a to-HARQ_feedback timing indicator (PDSCH-to-HARQ_feedback timing indicator),
The DAI and the PDSCH-to-HARQ_feedback timing indicator are used as HARQ process extension values. In claim 1,
The operation method of the terminal is,
It includes performing a transmission operation of the HARQ feedback to the base station according to the information indicated by the first information,
When the first information indicates the first HARQ process group, the HARQ feedback transmission operation is performed, and when the first information indicates the second HARQ process group, the HARQ feedback transmission operation is performed. How the terminal operates that does not work. As a method of operating a base station in a communication system,
Setting a first HARQ process group including a plurality of Type 1-HARQ processes and a second HARQ process group including a plurality of Type 2-HARQ processes;
Transmitting a higher layer message including first configuration information of the first HARQ process group and second configuration information of the second HARQ process group to the terminal;
An RV field containing first information indicating one HARQ process group used for communication between the terminal and the base station among the first HARQ process group and the second HARQ process group, the first information indicating Transmitting an HPN field including second information indicating the number of a HARQ process belonging to one HARQ process group and control information including resource allocation information to the terminal; and
It includes transmitting data to the terminal based on the control information,
The plurality of Type 1-HARQ processes includes a plurality of HARQ processes that support HARQ feedback, and the plurality of Type 2-HARQ processes includes a plurality of HARQ processes that do not support HARQ feedback, and are included in the RV field. When the first information indicates the first HARQ process group, the HPN field further includes information indicating an extension value of PDSCH-to-HARQ_feedback timing. In claim 7,
The first configuration information includes information about the first HARQ process group to which the plurality of Type 1-HARQ processes belong and HARQ process numbers set for the plurality of Type 1-HARQ processes. In claim 7,
The second configuration information includes information about the second HARQ process group to which the plurality of Type 2-HARQ processes belong and HARQ process numbers set for the plurality of Type 2-HARQ processes. delete In claim 7,
When the second information included in the HPN field indicates the number of one of the plurality of type 2-HARQ processes belonging to the second HARQ process group, the control information includes DAI and PDSCH-to-HARQ_feedback further includes a timing indicator,
The DAI and the PDSCH-to-HARQ_feedback timing indicator are used as HARQ process extension values. In claim 7,
The operating method of the base station is,
It includes performing a reception operation of HARQ feedback for the data from the terminal according to the information indicated by the first information,
When the first information indicates the first HARQ process group, the HARQ feedback reception operation is performed, and when the first information indicates the second HARQ process group, the HARQ feedback reception operation is performed. How a base station operates that does not work. As a terminal in a communication system,
processor;
a memory that communicates electronically with the processor; and
Contains instructions stored in the memory,
When the instructions are executed by the processor, the instructions allow the terminal to:
Receiving a higher layer message including first configuration information of a first HARQ process group and second configuration information of a second HARQ process group from the base station;
An RV field containing first information indicating one HARQ process group used for communication between the terminal and the base station among the first HARQ process group and the second HARQ process group, the first information indicating Receive from the base station an HPN field including second information indicating the number of a HARQ process belonging to one HARQ process group, and control information including resource allocation information;
receive data from the base station based on the resource allocation information; and
Determining whether to transmit HARQ feedback for the data according to the first information included in the control information,
The first HARQ process group includes a plurality of type 1-HARQ processes that support the HARQ feedback, and the second HARQ process group includes a plurality of type 2-HARQ processes that do not support the HARQ feedback, When the first information included in the RV field indicates the first HARQ process group, the HPN field further includes information indicating an extension value of PDSCH-to-HARQ_feedback timing. , terminal. In claim 13,
The terminal operates to cause the first configuration information to include information about the first HARQ process group to which the plurality of Type 1-HARQ processes belong and the HARQ process number configured for the plurality of Type 1-HARQ processes. . In claim 13,
The terminal operates to cause the second configuration information to include information about the second HARQ process group to which the plurality of Type 2-HARQ processes belong and the HARQ process number configured for the plurality of Type 2-HARQ processes. . delete In claim 13,
When the second information included in the HPN field indicates the number of one of the plurality of type 2-HARQ processes belonging to the second HARQ process group, the control information includes DAI and PDSCH-to-HARQ_feedback further includes a timing indicator,
operative to cause the DAI and the PDSCH-to-HARQ_feedback timing indicator to be used as a HARQ process extension value. In claim 13,
The commands allow the terminal to
Performing a transmission operation of the HARQ feedback to the base station according to the information indicated by the first information,
When the first information indicates the first HARQ process group, the HARQ feedback transmission operation is performed, and when the first information indicates the second HARQ process group, the HARQ feedback transmission operation is performed. A terminal that operates to cause something that does not work.

Images