KR20210149605A - Method and apparatus for transmitting and receiving feedback signal in communication system - Google Patents

Abstract

According to an embodiment of the present invention, a method for transmitting a feedback signal performed by a first terminal in a communication system, comprises the steps of: receiving first setting information on a first PUCCH format for feedback for unicast transmission and a second PUCCH format for feedback on multicast transmission, from a first base station; receiving a first DCI for scheduling first DL data; receiving the first DL data; and performing a feedback operation on the first DL data. The step of receiving the first DCI and the step of performing a feedback operation on the first DL data can be performed in different schemes in a case that the first DL data is DL data transmitted in accordance with a unicast transmission scheme and a case of being transmitted in accordance with a multicast transmission scheme. Therefore, transmission/reception of a feedback signal can be efficiently performed.

Description

Method and apparatus for transmitting and receiving a feedback signal in a communication system

The present invention relates to a method and apparatus for transmitting and receiving a feedback signal in a communication system, and more particularly, to an apparatus for setting a feedback method for downlink signal transmission and transmitting and receiving a feedback signal according to the set feedback method.

With the development of information and communication technology, various wireless communication technologies are being developed. Representative wireless communication technologies include long term evolution (LTE) and new radio (NR) defined in 3rd generation partnership project (3GPP) standards. LTE may be one of 4G (4th Generation) wireless communication technologies, and NR may be one of 5G (5th Generation) wireless communication technologies.

For the processing of wireless data rapidly increasing after commercialization of a 4G communication system (eg, a communication system supporting LTE), a frequency band of a 4G communication system (eg, a frequency band of 6 GHz or less) as well as a 4G communication system A 5G communication system (eg, a communication system supporting NR) that can use a frequency band higher than the frequency band of (eg, a frequency band of 6 GHz or more) is being considered.

In a communication system, when one transmitting node transmits a signal to one receiving node, it is called point-to-point (P2P) transmission or one-to-one transmission, and one transmitting node transmits a signal to a plurality of receiving nodes. It may be referred to as point to multipoint (P2MP) transmission or one-to-many transmission. P2P transmission or one-to-one transmission may be performed according to a unicast scheme. P2MP transmission or one-to-many transmission may be performed according to a transmission scheme such as multicast, groupcast, or broadcast.

Simultaneous transmission of the same signal (eg, control signal, data, etc.) from one upper node (eg, a base station) to a plurality of lower nodes (eg, terminals) using a common resource is called multicast downlink transmission. can In the case of multicast downlink transmission, the downlink signal may be transmitted through a common downlink resource. On the other hand, a feedback signal (eg, a hybrid automatic repeat request (HARQ) signal) returned by each lower node for multicast downlink transmission may be returned through uplink resources independent of each other according to the same or different feedback schemes. . In multicast downlink transmission, a procedure for upper node and lower node to set a feedback scheme and to perform feedback may have to be performed in a different way from that in unicast downlink transmission. A technique for efficiently setting a feedback scheme and performing feedback in multicast downlink transmission may be required.

SUMMARY OF THE INVENTION An object of the present invention is to efficiently configure a feedback scheme and transmit/receive a feedback signal when one upper node performs multicast downlink transmission to a plurality of lower nodes. To provide a method and apparatus for transmitting and receiving a feedback signal.

In a method for transmitting a feedback signal performed by a first terminal of a communication system according to an embodiment of the present invention for achieving the above object, feedback for unicast transmission from a first base station of the communication system is provided. Receiving first configuration information including configuration information of a first physical uplink control channel (PUCCH) format for a first physical uplink control channel (PUCCH) format and configuration information of a second PUCCH format for feedback on multicast transmission , receiving, from the first base station, first DL control information (DCI) for scheduling first DL data, from the first base station, based on the first configuration information and the first DCI receiving the first DL data; and performing, with the first base station, a feedback operation on the first DL data based on the first configuration information and the first DCI, wherein the first Receiving the DCI and performing the feedback operation on the first DL data may include a case in which the first DL data is DL data transmitted according to the unicast transmission method and is transmitted according to the multicast transmission method. In the case of DL data, it may be characterized in that it is performed in different ways.

The step of performing the feedback operation on the first DL data may include: when the first DL data is DL data transmitted according to the multicast transmission scheme, the first terminal including the first terminal by the first DCI A plurality of physical uplink control channel (PUCCH) resource blocks (RB) allocated to the first terminal separately allocated to each of the plurality of terminals included in one terminal group. Checking information of the first PUCCH RB; and transmitting a first feedback signal for the first DL data to the first base station through the first PUCCH RB.

The second PUCCH format may be defined to include a first information element (IE) indicating that the PUCCH is allocated to a plurality of RBs.

The step of performing the feedback operation on the first DL data may include: when the first DL data is DL data transmitted according to the multicast transmission scheme, the first terminal including the first terminal by the first DCI Checking information of a first PUCCH resource allocated to a first subgroup including the first terminal among a plurality of PUCCH resources divided for each of the plurality of subgroups into which one terminal group is divided, and The method may include transmitting a first feedback signal for the first DL data to the first base station through the first PUCCH resource.

The receiving of the first DCI includes: based on a DCI format of the first DCI or a type of a radio network temporary identifier (RNTI) that scrambles a cyclic redundancy check (CRC) of the first DCI, Check whether a new data indicator (NDI) field indicates whether DL data transmitted according to the unicast transmission method is initially transmitted or whether data transmitted according to the multicast transmission method is initially transmitted It may be characterized in that it comprises the step of

The receiving of the first DCI includes a hybrid automatic repeat request (HARQ) process of DL data in which the HPN field is transmitted according to the unicast transmission scheme, based on an HPN value indicated by the HPN field of the first DCI. N number of HPNs that the HPN field may indicate, including determining whether information related to Among the values, n HPN values are used to indicate information related to the HARQ process of DL data transmitted according to the unicast transmission method, and the remaining (Nn) HPN values are the values of DL data transmitted according to the multicast transmission method. It may be characterized in that it is used to indicate information related to the HARQ process.

The receiving of the first DCI may include, when the first DL data is DL data transmitted according to the multicast transmission scheme, the first DL data through a value of a downlink assignment index (DAI) field of the first DCI. Acquiring a counter-DAI value and a total-DAI value reflecting the DL data scheduling result according to the unicast transmission method and the DL data scheduling result according to the multicast transmission method until the time when data is scheduled can do.

When the first DL data is DL data transmitted according to the multicast transmission scheme, the first DCI may correspond to a DCI defined not to include a DAI field.

The first DL data corresponds to DL data transmitted according to the unicast transmission method, and the feedback signal transmission method includes scheduling, from the first base station, second DL data to be transmitted according to the multicast transmission method. Receiving a second DCI, receiving the second DL data from the first base station based on the first configuration information and the second DCI, and to the first base station, the first configuration information and performing a feedback operation on the second DL data based on the second DCI, wherein the first DCI indicates for a feedback procedure on the first DL data transmitted according to the unicast transmission method When the timing of the first PUCCH resource and the second PUCCH resource indicated by the second DCI for the feedback procedure for the second DL data transmitted according to the multicast transmission scheme are the same, feedback on the first DL data Both the operation and the feedback operation for the second DL data may be performed through the first PUCCH resource.

In the step of performing the feedback operation on the second DL data, the NACK-only HARQ method was instructed as a feedback method for the first terminal to perform a feedback procedure on DL data transmitted according to the multicast transmission method. In this case, it may be characterized in that the feedback operation on the second DL data is performed according to an ACK/NACK HARQ scheme instead of the indicated NACK-only HARQ scheme.

The performing of the feedback operation on the first DL data may include, when the first DL data is DL data transmitted according to the multicast transmission scheme, prior to transmission of the first DL data from the first base station. determining whether it is necessary to return a feedback signal to the first DL data based on the indicated first feedback method and whether the first DL data is normally received; if necessary, generating a first feedback signal for the first DL data, and transmitting the first feedback signal to the first base station, wherein the first feedback scheme includes the first configuration information; Through a radio resource control (RRC) message for controlling scheduling information of the first DCI or the first DL data, an ACK/NACK HARQ scheme, a NACK-only HARQ scheme, an ACK-only HARQ scheme, and a No-HARQ scheme It may be characterized in that it is selectively indicated.

A method for receiving a feedback signal performed by a first base station of a communication system according to another embodiment of the present invention for achieving the above object is, to a plurality of terminals of the communication system, a feedback for unicast transmission For transmitting first configuration information including configuration information of a first physical uplink control channel (PUCCH) format and configuration information of a second PUCCH format for feedback on multicast transmission step, transmitting first DL control information (DCI) for scheduling first DL data to at least one terminal among the plurality of terminals of the communication system, the first configuration information and the first Transmitting the first DL data to the at least one terminal based on 1 DCI, and based on the first configuration information and the first DCI, from the at least one terminal for the first DL data Receiving at least one feedback signal, wherein transmitting the first DCI and receiving the at least one feedback signal include: DL in which the first DL data is transmitted according to the unicast transmission scheme In the case of data and in the case of DL data transmitted according to the multicast transmission method, it may be characterized in that it is performed in different ways.

In the first DCI, when the first DL data is DL data transmitted according to the multicast transmission scheme, a plurality of PUCCH resource blocks (RBs) are included in the first terminal group of the communication system. configured to be separately allocated to each of the terminals of , and the receiving the at least one feedback signal includes: checking the plurality of PUCCH RBs allocated based on the first DCI; and the plurality of PUCCHs Receiving the at least one feedback signal for the first DL data from at least some of the plurality of terminals included in the first terminal group through the PUCCH RB of at least some of the RBs. can

The second PUCCH format may be defined to include a first information element (IE) indicating that the PUCCH is allocated to a plurality of RBs.

DCI for scheduling DL data transmitted according to the unicast transmission method and DCI for scheduling DL data transmitted according to the multicast transmission method are configured based on different DCI formats, and the first base station has different DCI It may be characterized in that a new data indicator (NDI) field of DCIs configured based on the format is operated independently of each other.

The first base station, in DCI scheduling DL data transmitted according to the unicast transmission method or DL data transmitted according to the multicast transmission method, N HPNs that can be indicated by a HARQ process number (HPN) field Among the values, n HPN values are used to indicate information related to a hybrid automatic repeat request (HARQ) process of DL data transmitted according to the unicast transmission scheme, and the remaining Nn HPN values are used according to the multicast transmission scheme. It may be characterized in that it is used to indicate information related to the HARQ process of transmitted DL data.

The first base station, DCI for scheduling DL data transmitted according to the unicast transmission method and DCI for scheduling DL data transmitted according to the multicast transmission method It is characterized in that it operates independently of each other in the HPN field can

In the transmitting of the first DCI, if the first DL data is DL data transmitted according to the multicast transmission method, scheduling DL data according to the unicast transmission method until the time when the first DL data is scheduled checking a result and a DL data scheduling result according to the multicast transmission method, and reflecting both the DL data scheduling result according to the unicast transmission method and the DL data scheduling result according to the multicast transmission method. and determining a counter-DAI value and a total-DAI value of a downlink assignment index (DAI) field of the first DCI.

The first DL data corresponds to DL data transmitted to a first terminal of the communication system according to the unicast transmission method, and the method for receiving a feedback signal includes a first terminal group including the first terminal, Transmitting a second DCI for scheduling second DL data to be transmitted according to a multicast transmission scheme, based on the first configuration information and the second DCI, to a plurality of terminals included in the first terminal group transmitting the second DL data, and based on the first configuration information and the second DCI, from at least some of the plurality of terminals included in the first terminal group to the second DL data The method further comprises receiving at least one feedback signal for the first PUCCH resource and the second DCI indicated by the first DCI for a feedback procedure for first DL data transmitted according to the unicast transmission scheme. When the timing of the second PUCCH resource indicated for the feedback procedure for the second DL data transmitted according to the multicast transmission scheme is the same, the feedback signal for the first DL data and the feedback signal for the second DL data At least one feedback signal may be all received through the first PUCCH resource.

Prior to transmitting the plurality of DL data to the plurality of terminal groups of the communication system according to the multicast transmission scheme, the first base station has the first configuration information and a plurality of DCI for scheduling each of the plurality of DL data , and a plurality of RRC (radio resource control) messages for controlling scheduling information of the plurality of DL data indicate a feedback method to the plurality of UE groups, and the feedback method is an ACK/NACK HARQ method, NACK- The only HARQ scheme, the ACK-only HARQ scheme and the No-HARQ scheme are selected, and each of the plurality of terminal groups is independently indicated or is equally indicated for at least two or more terminal groups among the plurality of terminal groups. can be characterized as

According to an embodiment of the present invention, when the base station transmits downlink data to the terminal, either a unicast transmission method or a multicast transmission method may be used, or a unicast transmission method or multicast transmission method All methods can be used. The base station may instruct the terminal to provide information for the terminal to perform a feedback operation on downlink data transmitted according to the unicast transmission method or the multicast transmission method through DCI for scheduling downlink data to be transmitted to the terminal. have. Accordingly, a feedback operation between the base station and the terminal supporting both the unicast transmission method and the multicast transmission method can be efficiently performed.

1 is a conceptual diagram illustrating an embodiment of a communication system.
2 is a block diagram illustrating an embodiment of a communication node constituting a communication system.
3A and 3B are conceptual diagrams for explaining an embodiment of a control plane protocol and a user plane protocol of a communication system.
4 is a conceptual diagram for explaining an embodiment of a mapping structure between downlink channels in a communication system.
5 is a conceptual diagram for explaining an embodiment of a feedback signal transmission/reception operation in a communication system.
6 is a flowchart illustrating an embodiment of a method for transmitting and receiving a feedback signal between a first communication node and a second communication node in a communication system.

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

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

When an element is referred to as being “connected” or “connected” to another element, it is understood that it may be directly connected or connected to the other element, but other elements may exist in between. it should be On the other hand, when it is said that a certain element is "directly connected" or "directly connected" to another element, it should be understood that the other element does not exist in the middle.

The terms used in the present application are only used to describe specific embodiments, and are not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise. In the present application, terms such as “comprise” or “have” are intended to designate that a feature, number, step, operation, component, part, or combination thereof described in the specification exists, but one or more other features It should be understood that this does not preclude the existence or addition of numbers, steps, operations, components, parts, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in a commonly used dictionary should be interpreted as having a meaning consistent with the meaning in the context of the related art, and should not be interpreted in an ideal or excessively formal meaning unless explicitly defined in the present application. does not

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

Throughout the specification, a network is, for example, a wireless Internet such as WiFi (wireless fidelity), a wireless broadband internet (WiBro) or a mobile Internet such as a world interoperability for microwave access (WiMax), a global system for mobile communication (GSM). ) or 2G mobile communication network such as CDMA (code division multiple access), WCDMA (wideband code division multiple access) or 3G mobile communication network such as CDMA2000, high speed downlink packet access (HSDPA) or high speed uplink packet access (HSUPA) such as It may include a 3.5G mobile communication network, a 4G mobile communication network such as a long term evolution (LTE) network or an LTE-Advanced network, and a 5G mobile communication network.

Throughout the specification, a terminal refers to a mobile station, a mobile terminal, a subscriber station, a portable subscriber station, a user equipment, and an access terminal. and the like, and may include all or some functions of a terminal, a mobile station, a mobile terminal, a subscriber station, a portable subscriber station, a user equipment, an access terminal, and the like.

Here, a desktop computer that can communicate with a terminal, a laptop computer, a tablet PC, a wireless phone, a mobile phone, a smart phone, a smart watch (smart watch), smart glass, e-book reader, PMP (portable multimedia player), portable game console, navigation device, digital camera, DMB (digital multimedia broadcasting) player, digital voice Digital audio recorder, digital audio player, digital picture recorder, digital picture player, digital video recorder, digital video player ) can be used.

Throughout the specification, a base station is an access point, a radio access station, a Node B, an advanced nodeB, a base transceiver station, MMR ( It may refer to mobile multihop relay)-BS, etc., and may include all or some functions of a base station, an access point, a radio access station, a Node B, an eNodeB, a transceiver base station, and an MMR-BS.

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

1 is a conceptual diagram illustrating an embodiment of a communication system.

1, the communication system 100 is 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 4G communication (eg, long term evolution (LTE), LTE-A (advanced)), 5G communication (eg, NR (new radio)) defined in the 3rd generation partnership project (3GPP) standard ) can be supported. 4G communication may be performed in a frequency band of 6 GHz or less, and 5G communication may be performed in a frequency band of 6 GHz or more as well as a frequency band of 6 GHz or less.

For example, a plurality of communication nodes for 4G communication and 5G communication is a CDMA (code division multiple access) based communication protocol, WCDMA (wideband CDMA) based communication protocol, TDMA (time division multiple access) based communication protocol, FDMA (frequency division multiple access) based communication protocol, OFDM (orthogonal frequency division multiplexing) based communication protocol, Filtered OFDM based communication protocol, CP (cyclic prefix)-OFDM based communication protocol, 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 protocol, FBMC (filter bank multi-carrier)-based communication protocol, UFMC (universal filtered multi-carrier)-based communication protocol, SDMA (Space Division Multiple Access)-based communication protocol, etc. can be supported. .

Also, the communication system 100 may further include a core network. When 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), and a mobility management entity (MME). have. When the communication system 100 supports 5G communication, the core network may include a user plane function (UPF), a session management function (SMF), an access and mobility management function (AMF), and the like.

On the other hand, 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) may each have the following structure.

2 is a block diagram illustrating an 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 transceiver 230 connected to a network to perform communication. In addition, the communication node 200 may further include an input interface device 240 , an output interface device 250 , a storage device 260 , and the like. Each of the components included in the communication node 200 may be connected by a bus 270 to communicate with each other.

However, each of the components included in the communication node 200 may not be connected to the common bus 270 but to the processor 210 through an individual interface or an individual bus. For example, the processor 210 may be connected to at least one of the memory 220 , the transceiver 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 mean 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 configured as at least one of a volatile storage medium and a non-volatile storage medium. For example, the memory 220 may be configured as at least one of a read only memory (ROM) and a random access memory (RAM).

Referring back to FIG. 1 , the communication system 100 includes a plurality of base stations 110 - 1 , 110 - 2 , 110 - 3 , 120 - 1 and 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 comprising communication system 100 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. have. 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, 120-2 is a NodeB (NodeB), an advanced NodeB (evolved NodeB), a BTS (base transceiver station), Radio base station (radio base station), radio transceiver (radio transceiver), access point (access point), access node (node), RSU (road side unit), RRH (radio remote head), TP (transmission point), TRP ( transmission and reception ooint), eNB, gNB, and the like.

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

Meanwhile, each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 may operate in different frequency bands or may operate in the same frequency band. Each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 may be connected to each other through an ideal backhaul link or a non-ideal backhaul link. , information can be exchanged with each other through an ideal backhaul link or a non-ideal backhaul link. Each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 may be connected to the core network through an ideal backhaul link or a non-ideal backhaul link. Each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 transmits a signal received from the core network to the corresponding terminals 130-1, 130-2, 130-3, 130 -4, 130-5, 130-6), and a signal received from the corresponding terminal (130-1, 130-2, 130-3, 130-4, 130-5, 130-6) is transmitted to the core network can be sent to

In addition, each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 transmits MIMO (eg, single user (SU)-MIMO, multi user (MU)- MIMO, massive MIMO, etc.), coordinated multipoint (CoMP) transmission, carrier aggregation (CA) transmission, transmission in an unlicensed band, device to device communication (D2D) (or, ProSe ( proximity services)), and the like. Here, each of the plurality of terminals 130-1, 130-2, 130-3, 130-4, 130-5, 130-6 is the base station 110-1, 110-2, 110-3, and 120-1. , 120-2) and corresponding operations, and operations supported by the base stations 110-1, 110-2, 110-3, 120-1, and 120-2 may be performed. For example, the second base station 110-2 may transmit a signal to the fourth terminal 130-4 based on the SU-MIMO method, and the fourth terminal 130-4 may transmit a signal based on the SU-MIMO method. A signal may be received from the second base station 110 - 2 . Alternatively, the second base station 110 - 2 may transmit a signal to the fourth terminal 130 - 4 and the fifth terminal 130 - 5 based on the MU-MIMO scheme, and the fourth terminal 130 - 4 . and each of the fifth terminals 130 - 5 may receive a signal from the second base station 110 - 2 by the MU-MIMO method.

Each of the first base station 110-1, the second base station 110-2, and the third base station 110-3 may transmit a signal to the fourth terminal 130-4 based on the CoMP scheme, and the fourth The terminal 130-4 may receive signals from the first base station 110-1, the second base station 110-2, and the third base station 110-3 by the CoMP method. Each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 is a terminal 130-1, 130-2, 130-3, 130-4 belonging to its own cell coverage. , 130-5, 130-6) and the CA method can transmit and receive signals. Each of the first base station 110-1, the second base station 110-2, and the third base station 110-3 controls D2D between the fourth terminal 130-4 and the fifth terminal 130-5. and each of the fourth terminal 130-4 and the fifth terminal 130-5 may perform D2D under the control of the second base station 110-2 and the third base station 110-3, respectively. .

Next, a method and apparatus for transmitting and receiving a feedback signal in a communication system will be described. Even when a method (eg, transmission or reception of a signal) performed in a first communication node among communication nodes is described, a corresponding second communication node is a method (eg, a method corresponding to the method performed in the first communication node) For example, reception or transmission of a signal) may be performed. That is, when the operation of the terminal is described, the corresponding base station may perform the operation corresponding to the operation of the terminal. Conversely, when the operation of the base station is described, the corresponding terminal may perform the operation corresponding to the operation of the base station.

Meanwhile, in a communication system, a base station may perform all functions of a communication protocol (eg, a remote radio transmission/reception function, a baseband processing function). Alternatively, a remote radio transmission/reception function among all functions of a communication protocol may be performed by a transmission reception point (TRP) (eg, f(flexible)-TRP), and a baseband processing function among all functions of a communication protocol may be performed by a baseband unit (BBU) block. The TRP may be a remote radio head (RRH), a radio unit (RU), or a transmission point (TP). The BBU block may include at least one BBU or at least one digital unit (DU). A BBU block may be referred to as a “BBU pool”, a “centralized BBU”, or the like. The TRP may be connected to the BBU block through a wired fronthaul link or a wireless fronthaul link. A communication system composed of a backhaul link and a fronthaul link may be as follows. When the function split method of the communication protocol is applied, the TRP may selectively perform some functions of the BBU or some functions of medium access control (MAC)/radio link control (RLC).

3A and 3B are conceptual diagrams for explaining an embodiment of a control plane and a user plane of a wireless protocol in a communication system.

In a wireless connection section between communication nodes, a radio interface protocol may be defined. For example, the air interface protocol may be divided into a vertically configured physical layer, a data link layer, and a network layer.

The wireless interface protocol may be divided into a control plane 310 shown in FIG. 3A and a user plane 320 shown in FIG. 3B . The control plane 310 may be a plane for transmitting control signals. The control signal may be referred to as a signaling signal. The user plane 320 may be a plane for user data transmission.

Referring to FIGS. 3A and 3B , the air interface protocol may include three lower layers of an Open System Interconnection (OSI) reference model widely known in general communication systems. For example, the first layer L1 may include physical (physical; PHY) layers 331 and 341 or 351 and 361 . The second layer (L2) is a Medium Access Control (MAC) layer (332 and 342, or 352 and 362), a Radio Link Control (RLC) layer (333 and 343, or 353 and 363) and Packet Data Convergence Protocol (PDCP) layers 334 and 344, or 354 and 364. In addition, the third layer (L3) may include Radio Resource Control (RRC) layers 335 and 345 . The air interface protocol exists as a pair in the terminal 330 or 350 and the base station 340 or 360 to be in charge of data transmission of the air interface. However, this is only an example for convenience of description, and the embodiment of the present invention is not limited thereto. For example, in an embodiment of a communication system, only some of the layers shown in FIGS. 3A and 3B may be used, or layers not shown in FIGS. 3A and 3B may be additionally defined and used.

The PHY layers 331 and 341 or 351 and 361 as the first layer may provide an information transfer service to a higher layer by using a physical channel. The PHY layers 331 and 341 or 351 and 361 may be connected to the higher MAC layers 332 and 342 or 352 and 362 through a transport channel. Data between the PHY layers 331 and 341 , or 351 and 361 and the MAC layers 332 and 342 , or 352 and 362 may travel through a transport channel. The transport channel may be divided into a dedicated channel and a common channel depending on whether the channel is shared. Data between different PHY layers may move through a physical channel using radio resources. That is, data between the PHY layer 331 or 351 on the terminal 330 or 350 side and the PHY layer 341 or 361 on the base station 340 or 360 side may move through a physical channel using radio resources.

The MAC layers 332 and 342 or 352 and 362 of the second layer may map a plurality of logical channels to a plurality of transport channels. Also, the MAC layers 332 and 342 or 352 and 362 may perform a logical channel multiplexing function for mapping a plurality of logical channels to one transport channel. The MAC layers 332 and 342, or 352 and 362 may be connected to the RLC layers 333 and 343, or 353 and 363, which are higher layers, by logical channels. The logical channel may be divided into a control channel for transmitting information on the control plane 310 and a traffic channel for transmitting information on the user plane 320 according to the type of transmitted information.

The RLC layer (333 and 343, or 353 and 363) of the second layer divides and concatenates the data received from the upper layer so that the lower layer is suitable for transmitting data in the radio section. can be adjusted In addition, the RLC layer (333 and 343, or 353 and 363) is a transparent mode (transparent mode; TM) to satisfy the various QoS (Quality of Service) required by each radio bearer (Radio Bearer; RB), non-response mode (un-acknowledged mode; UM) and an acknowledgment mode (acknowledged mode; AM) may be provided. In particular, the AM RLC may perform a retransmission function through an automatic repeat request (ARQ) function for reliable data transmission.

The PDCP layers 334 and 344 or 354 and 364 of the second layer may perform a header compression function. The header compression function reduces the size of a relatively large IP packet header containing unnecessary control information in order to increase transmission efficiency when transmitting IP packets in a wireless section with a small bandwidth such as IPv4 (internet protocol version 4) or IPv6. can mean In other words, the header compression function allows only necessary information to be transmitted in the header part of data, thereby increasing the transmission efficiency of the radio section.

In addition, the PDCP layers 334 and 344 or 354 and 364 may perform a security function. The security function may include a ciphering function to prevent data interception by a third party and an integrity protection function to prevent data manipulation by a third party.

The RRC layers 335 and 345 of the third layer may be defined only in the control plane 310 . The RRC layers 335 and 345 may control logical channels, transport channels, and physical channels related to configuration, re-configuration, and release of RBs.

The RB may mean a logical path provided by the first and second layers of a radio protocol for data transfer between the terminal 330 or 350 and the base station 340 or 360 . In general, setting an RB may refer to a process of defining characteristics of a radio protocol layer and channel required to provide a specific service, and setting each specific parameter and operation method. The RB may include a signaling RB (SRB) and a data RB (DRB). The SRB may be used as a path for transmitting an RRC message in the control plane 310 . The DRB may be used as a path for transmitting user data in the user plane 320 .

4 is a conceptual diagram for explaining an embodiment of a mapping structure between downlink channels in a base station of a communication system.

4, it can be seen that an embodiment of a mapping structure between downlink channels such as a downlink logical channel 410, a downlink transmission channel 430, and a downlink physical channel 450 in a base station of a communication system is illustrated.

Downlink logical channels (downlink logical channels) 410 are channels managed by the MAC layer, and may be defined according to the type of transmitted information. Downlink logical channels 410 may be mapped with downlink transport channels 430 by the MAC layer. Downlink transport channels 430 are channels managed by the PHY layer, and may be mapped to downlink physical channels 450 .

The downlink logical channels 410 include a Multicast Traffic Channel (MTCH) 411, a Multicast Control Channel (MCCH) 412, a Paging Control Channel (PCCH) 413, a Broadcast Control Channel (BCCH) 414, CCCH (Common Control Channel) (415), DCCH (Dedicated Control Channel) (416), DTCH (Dedicated Transport Channel) (417), SC-MTCH (Single-Cell Multicast Traffic Channel) (418), SC-MCCH (Single) -Cell Multicast Control Channel) (419) and the like. The downlink transmission channels 430 include a Multicast Channel (MCH) 431, a Paging Channel (PCH) 432, a Broadcast Channel (BCH) 433, and a Downlink Shared Channel (DL-SCH) 434. can The downlink physical channels 450 may include a Physical Multicast Channel (PMCH) 451 , a Physical Broadcast Channel (PBCH) 452 , and a PDSCH 453 . However, this is only an example for convenience of description, and the embodiment of the present invention is not limited thereto. For example, in an embodiment of the communication system, only some of the channels shown in FIG. 4 may be used, or channels not shown in FIG. 4 may be additionally defined and used.

The MTCH 411 may mean a logical channel for transmitting multimedia broadcast/multicast service (MBMS) traffic data. The MCCH 412 may mean a logical channel for transmitting control information necessary for reception of the MTCH 411 . The MTCH 411 and the MCCH 412 may be mapped to the MCH 431 of the downlink transmission channel. The MCH may be mapped to the PMCH 451 among downlink physical channels. The PCCH 413 may refer to a logical channel used to notify a change in system information and paging a UE whose location in units of cells is not known to the network. The PCCH 413 may be mapped to a PCH 432 of a downlink transmission channel.

The BCCH 414 may mean a logical channel used to broadcast system information to arbitrary terminals in the base station. The BCCH 414 may be divided and mapped into a BCH 433 and a DL-SCH 434 among downlink transmission channels according to transmitted information. BCH 433 and DL-SCH 434 may be mapped to PBCH 452 and PDSCH 453 , respectively. The BCCH 414 may include a master information block (MIB) transmitted through the PBCH 452 and a system information block (SIB) transmitted through the PDSCH 453 .

The CCCH 415 may mean a logical channel used for transmitting and receiving control information (eg, control information related to random access) between the terminal and the base station in a situation where the terminal and the base station do not establish an RRC connection. The DDCH 416 may mean a logical channel used for transmitting dedicated control information between the terminal and the base station in a situation in which the terminal establishes an RRC connection with the base station. The DTCH 417 may mean a logical channel used to transmit user traffic data of the terminal. The SC-MTCH 418 may refer to a logical channel used for single cell point-to-multipoint (SC-PTM) transmission. The SC-MCCH 419 may mean a logical channel for transmitting control information necessary for reception of the SC-MTCH 418 . CCCH 415 , DCCH 416 , DTCH 417 , SC-MTCH 418 , and SC-MCCH 419 may be mapped to DL-SCH 434 among downlink transport channels.

Among the downlink logical channels, the MTCH 411 , MCCH 412 , PCCH 413 , BCCH 414 , and CCCH 415 may be shared by all terminals. On the other hand, the DCCH 416 and the DTCH 417 may be allocated exclusively to each terminal. The DCCHs 416 and DTCHs 417 allocated to the UE may be identified by a Logical Channel Identity (LCID). A terminal may have a plurality of DTCHs 417 according to QoS of traffic data provided with a service. For example, when the RRC layer of the base station determines that the UE needs to create a new radio bearer, the RRC layer requests the MAC layer to create a new DTCH 417 together with the required QoS information, and the MAC layer User traffic data may be scheduled and transmitted to the terminal according to the provided QoS information. Here, the QoS information is QoS class (QCI: QoS Class Identifier), resource type (Resource Type), priority (Priority), packet delay parameter (Packet Delay Budget), packet error loss rate (PLER: Packet Loss Error Rate, hereinafter ' PLER') and the like. Meanwhile, the SC-MTCH 418 and the SC-MCCH 419 may be allocated to a plurality of terminals.

When the base station simultaneously transmits the same downlink data to a plurality of terminals, the same data is simultaneously transmitted to a plurality of terminals using a common resource rather than a one-to-one transmission method in which a separate resource is allocated to each terminal to transmit data. One-to-many transmission may be efficient. Among the one-to-many transmission methods, a method of transmitting the same data to a plurality of unspecified terminals may be referred to as a broadcast method or the like. Among the one-to-many transmission methods, a method of transmitting the same data to a group of identified terminals may be referred to as a multicast method or a groupcast method.

For the one-to-many transmission method, for example, multimedia broadcast multicast services (MBMS) of 3G, evolved MBMS (eMBMS)/further evolved MBMS (FeMBMS) technology of LTE, etc. may be used. The MBMS technology can be largely divided into a multicast broadcast single frequency network (MBSFN) method and a single cell point to multipoint (SC-PTM) method. In terms of transmitting user data, the MBSFN scheme may transmit data to a plurality of terminals included in one or more cells through semi-static scheduling using a PMCH physical channel. Meanwhile, the SC-PTM scheme may transmit data to a plurality of terminals included in one cell through dynamic scheduling using a PDSCH physical channel.

In the case of group communication such as multicast or groupcast, temporary mobile group identity (TMGI), etc. may be defined to provide a service. TMGI may be used to identify terminals interested in group communication. In order to identify a control message for single-cell group communication using SC-PTM, an identifier such as a single-cell radio network temporary identifier (RNTI, SC-RNTI) may be defined. Each UE may identify control information for single cell group communication through SC-RNTI. The terminal may be instructed by a TMGI for identifying a specific group communication service through a base station or a server. Alternatively, the terminal may participate in group communication by receiving the TMGI of the service of interest in advance. For single cell group communication, the base station may define a group RNTI (G-RNTI) allocated to a corresponding group in order to provide a specific group communication service and allocate it to the terminals. G-RNTI may be configured to be associated with TMGI or associated with MBMS session ID or other identification information. In the case of a service provided based on group communication, terminals interested in the corresponding service may identify and receive a desired service by checking the TMGI. When the base station informs the terminal of the mapping relationship between the G-RNTI and the TMGI through a predetermined control signal, the terminal can check the TMGI of the group communication service it wants. Each terminal may receive data of a desired service through the PDSCH scheduled by the PDCCH scrambled by the identified TMGI and the mapped G-RNTI.

5 is a conceptual diagram for explaining an embodiment of a feedback signal transmission/reception operation in a communication system.

Referring to FIG. 5 , in an embodiment of a communication system, a feedback signal transmission/reception method may be used to improve reliability and efficiency of wireless communication. When the transmitting node of the communication system transmits a radio signal to the receiving node, the receiving node may return a feedback signal indicating information on whether the radio signal transmitted from the transmitting node is normally received to the transmitting node. For example, in an embodiment of the communication system, a feedback scheme based on a hybrid automatic repeat request (HARQ) protocol or a HARQ feedback scheme may be used.

In the feedback method based on the HARQ protocol, if the receiving node succeeds in decoding the first signal transmitted from the transmitting node, it may return a feedback signal indicating that the first signal has been normally received to the transmitting node. Here, the feedback signal indicating that the first signal has been normally received may correspond to the ACK signal. Meanwhile, when the decoding of the first signal transmitted from the transmitting node fails, the receiving node may return a feedback signal indicating that the first signal is not normally received to the transmitting node. Here, the feedback signal indicating that the first signal is not normally received may correspond to the NACK signal. When the transmitting node receives the NACK signal returned from the receiving node, it is determined that the first signal is not normally received by the receiving node, and retransmission of the first signal may be performed.

In an embodiment of the communication system, the receiving node may determine whether the first signal transmitted from the transmitting node is normally received in units of transport blocks (TB). For example, when the reception node fails to decode or detects an error in the decoding process of some TBs among the TBs constituting the first signal transmitted from the transmission node, the receiving node may return a NACK signal for the corresponding TB. However, this is only an example for convenience of description, and the embodiment of the present invention is not limited thereto. For example, the receiving node may determine whether decoding succeeds in units of code blocks (CBs) with respect to the first signal transmitted from the transmitting node. Alternatively, the receiving node may determine whether decoding succeeds in units of code block groups (CBGs) with respect to the first signal transmitted from the transmitting node. Here, CBG is a group consisting of at least one CB, which may be smaller than TB and greater than or equal to CB. The receiving node may return a NACK signal for the CB or CBG when decoding fails or an error is detected in the decoding process for some of the CBs or CBGs constituting the first signal transmitted from the transmitting node. have.

In an embodiment of the communication system, an upper node (eg, a base station) may perform downlink signal transmission to a lower node (eg, a terminal). The lower node may return a feedback signal based on the HARQ protocol to the upper node as feedback for the downlink signal transmission from the upper node. Hereinafter, an embodiment of a method for transmitting and receiving a feedback signal will be described with reference to a situation in which the terminal performs feedback based on the HARQ protocol with respect to the downlink data transmission performed by the base station for the terminal as an example. However, this is only an example for convenience of description, and the embodiment of the present invention is not limited thereto.

In an embodiment of the method for transmitting and receiving a feedback signal, the base station may transmit downlink data to the terminal through a physical downlink shared channel (PDSCH) 530 . The terminal may return a HARQ response signal to the downlink data transmitted from the base station to the base station through a physical uplink control channel (PUCCH) 550 . Alternatively, the terminal may return the HARQ response signal to the downlink data transmitted from the base station to the base station through a physical uplink shared channel (PUSCH). When the terminal succeeds in decoding downlink data transmitted from the base station, the terminal may return an ACK signal to the base station. Meanwhile, the terminal may return a NACK signal to the base station when decoding of downlink data transmitted from the base station fails. When the base station receives the NACK signal from the terminal, it is determined that the downlink data transmitted to the terminal is not normally received, and retransmission of the transmitted downlink data may be performed.

Before the base station transmits downlink data to the terminal through the PDSCH 530 , predetermined downlink control information (DCI) through a physical downlink control channel (PDCCH) 510 . can be transmitted to the terminal. DCI transmitted by the base station to the terminal prior to downlink data may be configured based on any one of DCI formats defined according to the 3GPP communication standard. For example, DCI transmitted by the base station to the terminal prior to downlink data may be configured based on DCI formats 1_0, 1_1, 1_2, and the like. Alternatively, the DCI transmitted by the base station to the terminal prior to downlink data may have a structure defined separately to support an embodiment of a method for transmitting and receiving a feedback signal. DCI transmitted by the base station to the terminal prior to downlink data may be configured to include some or all of the fields shown in Table 1.

In Table 1, the "DCI format identifier (Identifier for DCI formats)" field may indicate the DCI format. A "Frequency domain resource assignment" field may indicate resource assignment information of a frequency domain in which downlink data is transmitted. A "time domain resource assignment" field may indicate resource assignment information of a time domain in which downlink data is transmitted. The "Modulation and coding scheme" field is also referred to as an MCS field, and may indicate information related to a method in which downlink data is modulated and encoded. The "New data indicator" field is also referred to as an NDI field, and may indicate whether downlink data is initially transmitted or retransmitted. The "HARQ process number" field is also referred to as an HPN field, and may indicate information such as an identifier or sequence number for at least one HARQ process. The "downlink assignment index" field is also referred to as a DAI field, and may indicate the number of PDSCHs transmitted in one slot. The "PUCCH resource indicator" field is also referred to as a PRI field, and may indicate information on resources of the PUCCH 550 to be used in the HARQ response. The "PDSCH-to-HARQ_feedback timing indicator" field may indicate information such as a time interval or number of slots from the time the PDSCH 530 is transmitted until the HARQ response is transmitted. .

DCI transmitted by the base station to the terminal prior to downlink data may be configured to include at least a portion of one or more fields shown in Table 1. Each of the DCI fields that the base station transmits to the terminal prior to downlink data may be configured to have the same or different sizes as those shown in Table 1. The type of field included in DCI transmitted by the base station to the terminal prior to downlink data may be determined differently according to the format of the DCI. Alternatively, the type of the field included in the DCI may be determined differently according to the type of a radio network temporary identifier (RNTI) in which a cyclic redundancy check (CRC) is scrambled. For example, DCI format 1_0 CRC is C-RNTI (cell-RNTI), RA-RNTI (random access-RNTI), TC-RNTI (temporary cell RNTI), SI-RNTI (system information-RNTI), P-RNTI ( When scrambled by different types of RNTIs, such as paging-RNTI), it may be configured to include different types of fields for each. However, this is only an example for convenience of description, and the embodiment of the present invention is not limited thereto.

The base station may notify the terminal of one or more control information related to the first downlink data to be transmitted to the terminal by transmitting the first DCI to the terminal through the PDCCH 510 . For example, the first DCI transmitted by the base station to the terminal through the PDCCH 510 may include information on the first offset 520 . Here, the first offset 520 may mean an interval from when the PDCCH 510 is transmitted to the UE until the PDSCH 530 is transmitted to the UE in the time domain. The first offset 520 may be referred to as “DL assignment-to-PDSCH offset” or “K0”. Meanwhile, the first DCI transmitted by the base station to the terminal through the PDCCH 510 may include information of the second offset 540 . Here, the second offset 540 may mean an interval from when the PDSCH 530 is transmitted to the terminal in the time domain until the terminal returns an HARQ response through the PUCCH 550 . The second offset 540 may be referred to as “PDSCH-to-HARQ-ACK reporting offset” or “K1”.

When the base station transmits one or more downlink data to one or more terminals through each of one or more PDSCHs, the one or more terminals may return an HARQ response to the base station in the same slot or different slots. For example, when the base station transmits downlink data through different PDSCHs in a plurality of different slots, the base station adjusts second offset values corresponding to different PDSCHs, respectively, to thereby receive HARQ responses to different PDSCHs. It can be specified to be able to reply in the same slot.

Bits transmitted in response to HARQ may be defined in the form of a HARQ codebook. The HARQ codebook may be generated using a dynamic codebook method or a semi-static codebook method. In the dynamic codebook scheme, the size of the HARQ codebook may be determined based on a PDSCH actually scheduled for transmission of downlink data. The size of the HARQ codebook may be determined based on the number of TBs, CBs, or CBGs corresponding to the HARQ codebook. The size of the HARQ codebook may be determined based on values such as counter-DAI and total-DAI indicated through the DAI field of DCI. The counter-DAI may be referred to as “c-DAI” and may indicate the number of scheduled PDSCHs until the corresponding PDSCH is transmitted. That is, the value of c-DAI may increase according to the scheduling result for the PDSCH on the time axis. Here, when the PDSCH is scheduled for a plurality of carriers on the same time resource, the c-DAI value may increase in the order from the PDSCH allocated to the carrier having the low index to the PDSCH allocated to the carrier having the high index. Meanwhile, the total-DAI may be referred to as “t-DAI” and may indicate the cumulative number of PDSCHs scheduled for each slot until the corresponding slot. Meanwhile, in the semi-static codebook method, the size of the HARQ codebook may be set to a maximum possible value regardless of the actual PDSCH scheduling result.

Transmission of a signal from one communication node to one communication node may be referred to as point-to-point (P2P) transmission or one-to-one transmission. P2P transmission or one-to-one transmission may be performed according to a unicast transmission scheme. Configurations described for 'unicast transmission' in this specification may be equally or similarly applied to P2P transmission or one-to-one transmission.

Independently transmitting a downlink signal from one base station to each terminal may be referred to as unicast downlink transmission. One or more downlink signals (hereinafter, unicast downlink signals) transmitted in unicast downlink may be transmitted from the base station to one or more terminals through independent downlink resources. One or more terminals that have received the unicast downlink signal may independently perform an HARQ response to each unicast downlink signal.

Meanwhile, simultaneous transmission of the same signal from one communication node to a plurality of communication nodes may be referred to as point-to-multipoint (P2MP) transmission or one-to-many transmission. P2MP transmission or one-to-many transmission may be performed according to a transmission scheme such as multicast, groupcast, or broadcast. Configurations described for 'multicast transmission' in this specification may be equally or similarly applied to P2MP transmission, one-to-many transmission, groupcast transmission, or broadcast transmission.

Simultaneous transmission of the same downlink signal from one base station to a plurality of terminals may be referred to as multicast downlink transmission. A multicast downlink transmitted downlink signal (hereinafter, a multicast downlink signal) may be transmitted from a base station to a plurality of terminals through a common downlink resource. Meanwhile, the contents of the HARQ response to be returned by each of the plurality of terminals receiving the multicast downlink signal may be different from each other. Independent uplink resources may have to be allocated for the HARQ response of each of the plurality of terminals that have received the multicast downlink signal. Embodiments in which a base station and each terminal efficiently perform a feedback method setting operation and a feedback operation in multicast downlink transmission may be applied to a communication system.

6 is a flowchart illustrating an embodiment of a method for transmitting and receiving a feedback signal between a first communication node and a second communication node in a communication system.

Referring to FIG. 6 , the first communication node 601 may receive one or more signals from the second communication node 602 . The first communication node 601 may perform a feedback operation according to whether one or more signals transmitted from the second communication node 602 have been normally received. In an embodiment of the communication system, the first communication node 601 includes the terminals 130-1, 130-2, 130-3, 130-4, 130-5, 130-6 described with reference to FIG. 1, The terminal 330 described with reference to FIG. 3A , the terminal 350 described with reference to FIG. 3B , the terminal described with reference to FIG. 4 , and/or one or more terminals described with reference to FIG. 5 may be configured the same or similarly. have. The second communication node 602 includes the base stations 110-1, 110-2, 110-3, 120-1, and 120-2 described with reference to FIG. 1, the base station 340 described with reference to FIG. 3A, and FIG. The base station 360 described with reference to 3b, the base station described with reference to FIG. 4, and/or the base station described with reference to FIG. 5 may be configured the same or similarly. The first communication node 601 and the second communication node 602 may be configured the same as or similar to the communication node described with reference to FIG. 2 . Hereinafter, in describing an embodiment of a method for transmitting and receiving a feedback signal between a first communication node and a second communication node with reference to FIG. 6 , the content overlapping with those described with reference to FIGS. 1 to 5 may be omitted.

6 shows an embodiment of a method in which one first communication node 601 corresponding to a terminal and one second communication node 602 corresponding to a base station perform a mutual feedback signal transmission/reception procedure. can However, this is only an example for convenience of description, and the embodiment of the present invention is not limited thereto. For example, an embodiment of the communication system may be applied identically or similarly to a case where one or more base stations and one or more terminals and/or one or more terminal groups perform mutual feedback signal transmission/reception procedures.

The second communication node 602 may generate first setting information for the feedback operation of the first communication node 601 ( S610 ). The second communication node 602 may transmit the first setting information generated in step S610 to the first communication node 601 (S615). The first communication node 601 may receive first setting information for a feedback operation from the second communication node 602 ( S615 ). The first communication node 601 may perform a feedback operation on downlink data received from the second communication node 602 based on the first configuration information received from the second communication node 602 . The second communication node 602 may receive a feedback signal received from the first communication node 601 based on the first configuration information. For example, the second communication node 602 may use a unicast transmission method or a multicast transmission method when transmitting one or more PDSCHs to the first communication node 601 . The first communication node 601 transmits the PDSCH (hereinafter, unicast PDSCH) transmitted according to the unicast transmission method from the second communication node 602 or the PDSCH transmitted according to the multicast transmission method (hereinafter, multicast PDSCH). can receive The first communication node 601 may return a feedback signal for one or more unicast PDSCHs or multicast PDSCHs transmitted from the second communication node 602 to the second communication node 602 . Here, the feedback operation for the unicast PDSCH and the feedback operation for the multicast PDSCH may need to be separately performed. The first configuration information may include one or more pieces of information for allowing the first communication node 601 to separately perform a feedback operation for a unicast PDSCH and a feedback operation for a multicast PDSCH. The first setting information may include one or more pieces of information for causing the first communication node 601 and the second communication node 602 to operate according to at least some of the first to seventh embodiments of the following feedback signal transmission and reception method. can

A first embodiment of a method for transmitting and receiving a feedback signal

In the first embodiment of the method for transmitting and receiving a feedback signal, one or more feedback schemes may be established between the first communication node 601 and the second communication node 602 . For example, the first communication node 601 may use one or more of the following first to fourth feedback schemes according to whether the first signal transmitted by the second communication node 602 is normally received by the first communication node 601 . Feedback may be performed based on the method.

- First feedback method: when the first communication node 601 normally receives the first signal transmitted by the second communication node 602, it returns a feedback signal indicating the reception success, and fails to receive the first signal normally If it is, a feedback signal indicating a reception failure may be returned. The first feedback scheme may be referred to as “ACK/NACK feedback scheme” or “ACK/NACK HARQ scheme”.

- Second feedback method: When the first communication node 601 normally receives the first signal transmitted by the second communication node 602, it does not return a separate feedback signal, and the first communication node 601 cannot normally receive the first signal. In this case, a feedback signal indicating a reception failure may be returned. The second feedback scheme may be referred to as a “NACK-only feedback scheme” or a “NACK-only HARQ scheme”.

- Third feedback method: when the first communication node 601 normally receives the first signal transmitted by the second communication node 602, it returns a feedback signal indicating reception success, and fails to receive the first signal normally In this case, a separate feedback signal may not be returned. The third feedback scheme may be referred to as “ACK-only feedback scheme” or “ACK-only HARQ scheme”.

- Fourth feedback method: The first communication node 601 may not return the feedback signal regardless of whether the first signal transmitted by the second communication node 602 is normally received. The fourth feedback scheme may be referred to as “No Feedback scheme” or “No HARQ scheme”.

The first communication node 601 may correspond to one or more terminals, and the second communication node 602 may correspond to one or more base stations. Hereinafter, a first embodiment of a method for transmitting and receiving a feedback signal will be described by taking as an example a situation in which one base station and one or more terminals and/or one or more terminal groups perform a mutual feedback procedure. However, this is only an example for convenience of description, and the embodiment of the present invention is not limited thereto.

In a communication system including a base station performing multicast downlink transmission and one or more terminals, one or more feedback schemes may be used. One or more feedback schemes among the first to fourth feedback schemes may be configured between a base station performing multicast downlink transmission and one or more terminals.

A base station performing multicast downlink transmission may designate the same feedback method of any one of the first to fourth feedback methods to one or more terminals. Meanwhile, a base station performing multicast downlink transmission may designate a plurality of different feedback schemes for one or more terminals. The base station may designate the same or different feedback schemes for each terminal group based on a predetermined group identifier capable of classifying or distinguishing one or more terminals for each group. Here, the predetermined group identifier used by the base station for classification or classification of one or more terminals is a group communication service identifier (service ID), a temporary mobile group identity (TMGI), or a group-RNTI (G-RNTI). radio network temporary identifier) and the like.

One or more terminals receiving downlink data from the base station may perform feedback to the base station based on a feedback method indicated for each terminal or for each terminal group. For example, some of the plurality of terminals receiving downlink data may perform feedback according to a first feedback scheme and others may perform feedback according to a second feedback scheme. However, this is only an example for convenience of description, and the embodiment of the present invention is not limited thereto.

The base station may receive a feedback signal transmitted from one or more terminals. The base station may determine whether to retransmit the downlink signal based on the received feedback signal. The base station may not perform a retransmission operation for a terminal that has returned an ACK signal among one or more terminals to which the first feedback scheme is configured. Meanwhile, the base station may perform a retransmission operation for a terminal that has returned a NACK signal among one or more terminals to which the first feedback scheme is configured.

The base station may not perform a retransmission operation for a terminal that does not return a separate feedback signal among one or more terminals to which the second feedback scheme is configured. Meanwhile, the base station may perform a retransmission operation for a terminal that has returned a NACK signal among one or more terminals to which the second feedback scheme is configured.

The base station may not perform a retransmission operation for a terminal that has returned an ACK signal among one or more terminals to which the third feedback scheme is configured. Meanwhile, the base station may perform a retransmission operation for a terminal that does not return a separate feedback signal within a predetermined time interval among one or more terminals to which the third feedback scheme is configured.

The base station may not receive a separate feedback signal from one or more terminals to which the fourth feedback scheme is configured. The base station may not perform a separate retransmission operation even if a separate feedback signal is not returned to one or more terminals to which the fourth feedback scheme is configured. Alternatively, the base station may perform retransmission a predetermined number of times even if a separate feedback signal is not returned to one or more terminals to which the fourth feedback scheme is configured.

Second embodiment of feedback signal transmission/reception method

In the second embodiment of the feedback signal transmission/reception method, one or more feedback schemes may be established between the first communication node 601 and the second communication node 602 . For example, the first communication node 601 responds to one or more of the first to fourth feedback methods according to whether the first signal transmitted by the second communication node 602 is normally received by the first communication node 601 . Based on this, feedback can be performed. Here, the first to fourth feedback schemes may be the same as or similar to the first to fourth feedback schemes described with reference to the first embodiment of the method for transmitting and receiving a feedback signal. The first communication node 601 may correspond to one or more terminals, and the second communication node 602 may correspond to one or more base stations. Hereinafter, a second embodiment of a method for transmitting and receiving a feedback signal will be described by taking as an example a situation in which one base station and one or more terminals and/or one or more terminal groups perform a mutual feedback procedure. However, this is only an example for convenience of description, and the embodiment of the present invention is not limited thereto. Hereinafter, in the description of the second embodiment of the method for transmitting and receiving a feedback signal, content overlapping with that described in relation to the first embodiment of the method for transmitting and receiving a feedback signal may be omitted.

In the second embodiment of the feedback signal transmission/reception method, a base station performing multicast downlink transmission may designate the same feedback scheme among the first to fourth feedback schemes for one or more terminals. For example, the base station may instruct one or more terminals to perform feedback according to one of the first to fourth feedback methods through DCI transmitted to the terminal prior to the PDSCH. Alternatively, the base station may instruct one or more terminals to perform feedback according to one of the first to fourth feedback methods through an RRC message for controlling scheduling information of the PDSCH. Alternatively, the base station may instruct one or more terminals to perform feedback according to one of the first to fourth feedback methods in the process of initial access to the base station. However, this is only an example for convenience of description, and the embodiment of the present invention is not limited thereto.

In the second embodiment of the feedback signal transmission/reception method, a base station performing multicast downlink transmission may designate a plurality of different feedback schemes for a plurality of terminals. For example, the base station may instruct that some of the plurality of terminals receiving downlink data perform feedback according to the first feedback scheme and other parts perform feedback according to the second feedback scheme. However, this is only an example for convenience of description, and the embodiment of the present invention is not limited thereto. The base station may instruct a plurality of terminals to perform feedback according to a plurality of different feedback schemes through a control signal such as DCI transmitted prior to the PDSCH. Alternatively, the base station may instruct a plurality of terminals to perform feedback according to different methods through an RRC message for controlling scheduling information of the PDSCH.

In the second embodiment of the method for transmitting and receiving a feedback signal, a base station performing multicast downlink transmission uses the same or different feedback method for each terminal group based on a predetermined group identifier capable of classifying or distinguishing one or more terminals by group. can be specified. Here, the predetermined group identifier used by the base station for classification or classification of one or more terminals is a group communication service identifier (service ID), a temporary mobile group identity (TMGI), or a group-RNTI (G-RNTI). radio network temporary identifier) and the like. The base station may instruct the feedback method for one or more groups of terminals based on any one of the following first instruction method or the second instruction method.

- First indication method: A base station performing multicast downlink transmission may indicate a feedback method for each terminal group. The base station may classify or classify one or more terminals into one or more terminal groups based on a predetermined group identifier. The base station may designate any one of the first to fourth feedback schemes for each terminal group with respect to one or more terminal groups. According to the first indication method, a feedback method may be determined for each PDSCH. The base station may dynamically indicate the feedback method for each terminal group through a specific field of DCI for scheduling each PDSCH. Alternatively, the base station may quasi-statically instruct the feedback method for each terminal group through an RRC message for controlling scheduling information of each PDSCH. Here, the RRC message may be defined in the same or similar form as SC-MTCH-Info-r13 used for single cell point-to-multipoint (SC-PTM) communication, for example.

- Second indication method: A base station performing multicast downlink transmission may indicate the same feedback method to one or more groups of terminals. The base station may classify or classify one or more terminals into one or more terminal groups based on a predetermined group identifier. The base station may designate the same feedback method for a plurality of terminal groups. For example, the base station may instruct the terminals of the first and second terminal groups among all terminal groups to perform feedback according to the same feedback scheme, and the terminals of the third and fourth terminal groups according to the same feedback scheme. You can instruct them to give feedback. According to the second indication method, the same feedback method may be determined for a plurality of PDSCHs. The base station may quasi-statically instruct a feedback scheme for each terminal group through an RRC message for controlling scheduling information of a plurality of PDSCHs. Here, the RRC message may be defined in the same or similar form, for example, SCPTMConfiguration-r13 used for SC-PTM communication.

Each of the one or more terminal groups may include one or more terminals. Each terminal may perform a feedback operation to the base station based on the feedback method determined for the terminal group including the terminal. The base station may receive a feedback signal transmitted from one or more terminals. The base station may determine whether to retransmit the downlink signal based on the received feedback signal.

A third embodiment of a method for transmitting and receiving a feedback signal

In the third embodiment of the feedback signal transmission/reception method, one or more feedback schemes may be established between the first communication node 601 and the second communication node 602 . For example, the first communication node 601 responds to one or more of the first to fourth feedback methods according to whether the first signal transmitted by the second communication node 602 is normally received by the first communication node 601 . Based on this, feedback can be performed. Here, the first to fourth feedback schemes may be the same as or similar to the first to fourth feedback schemes described with reference to the first embodiment of the method for transmitting and receiving a feedback signal. The first communication node 601 may correspond to one or more terminals, and the second communication node 602 may correspond to one or more base stations. Hereinafter, a third embodiment of a method for transmitting and receiving a feedback signal will be described by taking as an example a situation in which one base station and one or more terminals and/or one or more terminal groups perform a mutual feedback procedure. However, this is only an example for convenience of description, and the embodiment of the present invention is not limited thereto. Hereinafter, in the description of the third embodiment of the method for transmitting and receiving a feedback signal, content overlapping with that described in relation to the first and/or second embodiment of the method for transmitting and receiving a feedback signal may be omitted.

In the third embodiment of the method for transmitting and receiving a feedback signal, the base station may configure or allocate uplink resources for performing a feedback operation to one or more terminals. The base station may configure or allocate uplink resources for performing the feedback operation based on the feedback method determined for one or more terminals. The base station may not allocate a separate PUCCH resource to the terminal to which the fourth feedback method (ie, No-HARQ method) is indicated.

A base station performing multicast downlink transmission may configure or allocate a common PUCCH resource for transmission of an HARQ response to one or more terminals receiving downlink data. For example, when the same PDSCH is transmitted to one or more terminals indicated by the second feedback method (ie, NACK-only HARQ method) or the third feedback method (ie, ACK-only HARQ method), the base station is all one or more terminals A common PUCCH resource for the HARQ response may be allocated to . In this case, PUCCH-format0 or PUCCH-format1 may be used as the format of the PUCCH. Here, PUCCH-format0 may have the same or similar structure as shown in Table 2, and PUCCH-format1 may have the same or similar structure as shown in Table 3.

PUCCH-format0 or PUCCH-format1 may be defined to include information elements (IEs) shown in Table 2 or Table 3. Alternatively, PUCCH-format0 or PUCCH-format1 may be defined to include some of the IEs shown in Table 2 or Table 3.

On the other hand, a base station performing multicast downlink transmission may configure or allocate a PUCCH resource that is distinguished from each other for transmission of an HARQ response to each of one or more terminals receiving downlink data. For example, one or more terminals to which the first feedback scheme is indicated may require independent PUCCH resources for transmission of the HARQ response for the PDSCH. The base station may configure or allocate different PUCCH resources to each of one or more terminals receiving the same PDSCH. In order for the base station to indicate to each of the one or more terminals receiving the same PDSCH the PUCCH resources that are distinguished from each other, information for distinguishing or identifying each of the one or more terminals included in one terminal group may be required. For example, the base station may distinguish one or more terminals included in one terminal group based on a predetermined identifier or member ID. The base station may allocate PUCCH resources differentiated from each other to each of one or more terminals included in one terminal group based on the following first to third allocation schemes.

- First allocation scheme: A base station performing multicast downlink transmission may extend and use PUCCH-format0 shown in Table 2 or PUCCH-format1 shown in Table 3 as a format of PUCCH. Through this, the base station may instruct the PUCCH to occupy a plurality of resource blocks (RBs) or physical resource blocks (PRBs). Specifically, the base station may add and use the first IE indicating the number of RBs or PRBs occupied by the PUCCH to PUCCH-format0 or PUCCH-format1. Here, the first IE may be referred to as “nrofPRBs”. Based on PUCCH-format0 or PUCCH-format1 extended by adding the first IE, one or more UEs may be allocated to one RB. Here, terminals allocated to the same RB may be distinguished based on a predetermined identifier or code.

-Second allocation scheme: A base station performing multicast downlink transmission defines and uses a new format for setting or allocating PUCCH resources that are distinguished from each other for transmission of HARQ responses to each of one or more terminals as a format of PUCCH. can For example, the base station may define and use the same or similar PUCCH format (hereinafter, PUCCH-formatX) as shown in Table 4 in order to indicate PUCCH resources differentiated from each other for each of one or more terminals receiving the same PDSCH.

The PUCCH-formatX may include an RRC IE indicating the number of RBs or PRBs occupied by the PUCCH for one or more terminals to return an HARQ response to the base station. Here, the RRC IE indicating the number of RBs or PRBs occupied by the PUCCH may be referred to as “nrofPRBs”.

- Third allocation method: a base station performing multicast downlink transmission divides one or more terminals included in one terminal group into one or more subgroups, and allocates different PUCCH resources to each subgroup can do. In the third allocation scheme, the base station may indicate one or more PUCCH resources to one or more terminals through one DCI. To this end, a mapping relationship between a PUCCH resource such as an identifier of a terminal group, an identifier of a subgroup, and/or an identifier of an individual terminal may be set or agreed between the base station and the terminal in advance. The base station may instruct each terminal through an RRC message, MAC CE, DCI, or the like in advance of a mapping relationship between an identifier of a terminal group, a subgroup, and/or an individual terminal, and the like, and a PUCCH resource. Each terminal may check the information of the PUCCH resource to be used for returning the HARQ response, based on the identifier of the terminal group, subgroup, and/or individual terminal, and information on the mapping relationship indicated by the base station. Here, the PUCCH resource indicated through one DCI may be distinguished only in the frequency domain and/or the code domain, not in the time domain. Through this, one or more terminals may return a HARQ response to the base station using PUCCH resources of different frequency domains and/or code domains in the same slot.

Fourth embodiment of feedback signal transmission/reception method

In the fourth embodiment of the method for transmitting and receiving a feedback signal, the first communication node 601 performs a feedback operation according to whether the first signal transmitted by the second communication node 602 is normally received by the first communication node 601 . can be done The first communication node 601 may correspond to one or more terminals, and the second communication node 602 may correspond to one or more base stations. Hereinafter, a fourth embodiment of a method for transmitting and receiving a feedback signal will be described by taking as an example a situation in which one base station and one or more terminals and/or one or more terminal groups perform a mutual feedback procedure. However, this is only an example for convenience of description, and the embodiment of the present invention is not limited thereto. Hereinafter, in the description of the fourth embodiment of the method for transmitting and receiving a feedback signal, content that overlaps with that described in relation to the first to third embodiments of the method for transmitting and receiving a feedback signal may be omitted.

In the fourth embodiment of the feedback signal transmission/reception method, the base station may transmit downlink data to one or more terminals. The base station may transmit downlink data to one or more terminals based on at least one of a unicast transmission method and a multicast transmission method. The base station may indicate whether downlink data is initially transmitted data or retransmitted data through a new data indicator (NDI) field of DCI transmitted to the terminal prior to downlink data transmission.

In an embodiment of the communication system, the base station may transmit downlink data to one or more terminals based on a unicast transmission method. In this case, the base station may indicate whether the downlink data is initially transmitted or retransmitted through the NDI field of the DCI for every PDSCH. For example, the base station toggles the value of the NDI field when a new PDSCH is first transmitted, and does not toggle the value of the NDI field when the previously transmitted PDSCH is retransmitted. can do. However, this is only an example for convenience of description, and the embodiment of the present invention is not limited thereto.

In an embodiment of the communication system, the base station may transmit downlink data to one or more terminals based on a multicast transmission scheme. In this case, the base station may indicate whether the downlink data is initially transmitted or retransmitted through the NDI field of the DCI for every PDSCH.

Meanwhile, in an embodiment of the communication system, the base station may transmit downlink data to one or more terminals using both the unicast transmission method and the multicast transmission method. For example, the base station may transmit a part of the PDSCH by a unicast transmission method and a part of the PDSCH by a multicast transmission method. In this case, each UE determines whether the NDI field of the DCI received prior to the PDSCH indicates whether the PDSCH (hereinafter, unicast PDSCH) according to the unicast transmission method indicates, or the PDSCH according to the multicast transmission method (hereinafter, multicast). PDSCH), it may be necessary to distinguish whether or not the information is indicated. The NDI field of DCI may need to be operated independently of each other when the PDSCH is transmitted using the unicast transmission method and when transmitted using the multicast transmission method. An NDI operation method for operating the NDI field of the DCI for the PDSCH transmitted by the base station in different ways may be required.

- First NDI operation method: The base station may operate so that DCI for unicast PDSCH and DCI for multicast PDSCH have different formats. NDI fields of DCIs having different formats may be configured to operate independently of each other. NDI fields of DCI for unicast PDSCH and DCI for multicast PDSCH having different DCI formats may be operated independently of each other. The UE may distinguish the NDI field of the DCI for the unicast PDCSH and the NDI field of the DCI for the multicast PDSCH based on the format of the DCI.

- Second NDI operation method: When the format of the DCI for the PDSCH transmitted in the unicast transmission method and the DCI format for the PDSCH transmitted in the multicast transmission method are the same, the base station sets the type of the RNTI in which the CRC is scrambled differently. By setting, DCI can be distinguished from each other. The UE may distinguish the NDI field of the DCI for the unicast PDCSH and the NDI field of the DCI for the multicast PDSCH based on the type of the RNTI in which the CRC is scrambled in the DCI.

Based on the first or second NDI operation method, the base station may independently operate the NDI field of the DCI for scheduling the unicast PDSCH and the NDI field of the DCI for scheduling the multicast PDSCH. For example, the NDI field of the DCI for scheduling the unicast PDSCH may be toggled based only on whether the unicast PDSCH is initially transmitted or retransmitted. Meanwhile, the NDI field of the DCI for scheduling the multicast PDSCH may be toggled based only on whether the multicast PDSCH is initially transmitted or retransmitted.

Fifth embodiment of feedback signal transmission/reception method

In the fifth embodiment of the feedback signal transmission/reception method, the first communication node 601 performs a feedback operation according to whether the first signal transmitted by the second communication node 602 is normally received by the first communication node 601 . can be done The first communication node 601 may correspond to one or more terminals, and the second communication node 602 may correspond to one or more base stations. Hereinafter, a fifth embodiment of a method for transmitting and receiving a feedback signal will be described by taking as an example a situation in which one base station and one or more terminals and/or one or more terminal groups perform a mutual feedback procedure. However, this is only an example for convenience of description, and the embodiment of the present invention is not limited thereto. Hereinafter, in the description of the fifth embodiment of the method for transmitting and receiving a feedback signal, content that overlaps with that described in relation to the first to fourth embodiments of the method for transmitting and receiving a feedback signal may be omitted.

In the fifth embodiment of the method for transmitting and receiving a feedback signal, the base station may transmit downlink data to one or more terminals. The base station may transmit downlink data to one or more terminals based on at least one of a unicast transmission method and a multicast transmission method. The base station may indicate the sequence or index of the HARQ response to be transmitted from the terminal through the HPN (HARQ process number) field of the DCI transmitted to the terminal prior to downlink data transmission. When the HPN field has a size of n bits, a maximum of 2 ⁿ distinct HPN values may be indicated. For example, as shown in Table 1, the HPN field of DCI may have a size of 4 bits, and in this case, up to 16 distinct HPN values may be indicated. In other words, when the HPN field has a size of 4 bits, it can be seen that HARQ process capability or HARQ process capability corresponds to 16. However, this is only an example for convenience of description, and the embodiment of the present invention is not limited thereto.

In an embodiment of the communication system, the base station may transmit downlink data to one or more terminals based on a unicast transmission method. In this case, since each terminal receives the PDSCH independently of each other, each terminal may be independently instructed by the HPN.

In an embodiment of the communication system, the base station may transmit downlink data to one or more terminals based on a multicast transmission scheme. In this case, one or more terminals receiving the same PDSCH may all be instructed with the same HPN through DCI received prior to the PDSCH.

Meanwhile, in an embodiment of the communication system, the base station may transmit downlink data to one or more terminals using both the unicast transmission method and the multicast transmission method. For example, the base station may transmit a part of the PDSCH by a unicast transmission method and a part of the PDSCH by a multicast transmission method. In this case, each UE may need to distinguish whether the HPN field of the DCI received prior to the PDSCH indicates whether the unicast PDSCH or the multicast PDSCH is indicated. When the base station transmits the PDSCH in different ways, an HPN operation method for allowing the UE to distinguish between HPN information for unicast PDSCH and HPN information for multicast PDSCH may be required.

- First HPN operation method: The base station may operate the DCI for the unicast PDSCH and the HPN field of the DCI for the multicast PDSCH separately from each other. In this case, the HPN field of the DCI for the unicast PDSCH may indicate only the index of the HARQ process for the unicast PDSCH, and the HPN field of the DCI for the multicast PDSCH may indicate only the index of the HARQ process for the multicast PDSCH. can

- Second HPN operation method: The base station may use some of the HARQ process capabilities determined according to the size of the HPN field of DCI for unicast PDSCH and the rest for multicast PDSCH. If the HPN field has a size of n bits, a maximum of 2 ⁿ distinct HPN values may be indicated. Here, the base station may use X HPN values for unicast PDSCH, and 2 ⁿ -X HPN values may use for multicast PDSCH. For example, when the HPN field has a size of 4 bits, the base station uses HPNs 0 to 7 for unicast PDSCH, and HPNs 8 to 15, out of 16 HPNs, for multicast PDSCH. . In this case, when the HPN field of DCI indicates any one of 0 to 7, the UE may determine that it indicates the HPN for the unicast PDSCH, and the HPN field indicates any one of 8 to 15. In this case, it can be determined that the HPN for the multicast PDSCH is indicated.

Sixth embodiment of feedback signal transmission/reception method

In the sixth embodiment of the feedback signal transmission/reception method, the first communication node 601 performs a feedback operation according to whether the first signal transmitted by the second communication node 602 is normally received by the first communication node 601 . can be done The first communication node 601 may correspond to one or more terminals, and the second communication node 602 may correspond to one or more base stations. Hereinafter, a sixth embodiment of a method for transmitting and receiving a feedback signal will be described by taking as an example a situation in which one base station and one or more terminals and/or one or more terminal groups perform a mutual feedback procedure. However, this is only an example for convenience of description, and the embodiment of the present invention is not limited thereto. Hereinafter, in the description of the sixth embodiment of the method for transmitting and receiving a feedback signal, content that overlaps with that described in relation to the first to fifth embodiments of the method for transmitting and receiving a feedback signal may be omitted.

In the sixth embodiment of the method for transmitting and receiving a feedback signal, the base station may transmit downlink data to one or more terminals. The base station may transmit downlink data to one or more terminals based on at least one of a unicast transmission method and a multicast transmission method. The base station may indicate the number of HARQ response signals transmitted in one slot through a downlink assignment index (DAI) field of DCI transmitted to the terminal prior to downlink data transmission. Bits transmitted in response to HARQ may be defined in the form of a HARQ codebook. The HARQ codebook may be set based on information indicated through the DAI field.

The base station may transmit a unicast PDSCH to one or more terminals. Each terminal may receive a unicast PDSCH distinguished from each other from the base station. One or more terminals receiving the unicast PDSCH from the base station may be instructed with different DAI values through the corresponding DCI.

The base station may transmit a multicast PDSCH to one or more terminals. One or more terminals may receive the same multicast PDSCH from the base station. One or more terminals receiving the same multicast PDSCH from the base station may be instructed with the same DAI value through the corresponding DCI.

Meanwhile, the base station may transmit both the unicast PDSCH and the multicast PDSCH. In this case, each terminal may receive any one type of PDSCH from the base station to the unicast PDSCH and the multicast PDSCH, or may receive both the unicast PDSCH and the multicast PDSCH. The UE receiving both the unicast PDSCH and the multicast PDSCH may transmit HARQ responses for each of the received unicast PDSCH and multicast PDSCH in the same slot. In this case, the HARQ codebook may include both bits of the HARQ response for both the unicast PDSCH and the multicast PDSCH. In order to transmit the HARQ response of the terminal receiving both the unicast PDSCH and the multicast PDSCH, the base station may operate the DAI field of DCI according to the following first and second DAI operation methods.

- First DAI operation method: The base station may reflect the scheduling result of the unicast PDSCH and the scheduling result of the multicast PDSCH together when determining the value of the DAI field of the DCI for scheduling the unicast PDSCH. For example, in the DAI field of the DCI for scheduling the unicast PDSCH, the value of c-DAI is the sum of the number of unicast PDSCHs and multicast PDSCHs scheduled until the corresponding unicast PDSCH is transmitted on the time axis. Can be determined. In addition, the value of t-DAI in the DAI field of the DCI for scheduling the unicast PDSCH may be determined as a value obtained by adding the cumulative number of unicast PDSCHs scheduled up to the corresponding slot on a slot-by-slot basis and the cumulative number of multicast PDSCHs.

- Second DAI operation method: The UE may perform a HARQ response to the unicast PDSCH or the multicast PDSCH regardless of the DAI value of the DCI field for the multicast PDSCH. For example, in the process of generating the codebook for the HARQ response of the terminal, the DAI value of the DCI field for the multicast PDSCH may not be considered. Alternatively, the base station may not include the DAI field when transmitting DCI for the multicast PDSCH to the terminal.

Seventh embodiment of feedback signal transmission/reception method

In the seventh embodiment of the method for transmitting and receiving a feedback signal, the first communication node 601 performs a feedback operation according to whether the first signal transmitted by the second communication node 602 is normally received by the first communication node 601 . can be done The first communication node 601 may correspond to one or more terminals, and the second communication node 602 may correspond to one or more base stations. Hereinafter, a seventh embodiment of a method for transmitting and receiving a feedback signal will be described by taking as an example a situation in which one base station and one or more terminals and/or one or more terminal groups perform a mutual feedback procedure. However, this is only an example for convenience of description, and the embodiment of the present invention is not limited thereto. Hereinafter, in the description of the seventh embodiment of the method for transmitting and receiving a feedback signal, content overlapping with that described in relation to the first to sixth embodiments of the method for transmitting and receiving a feedback signal may be omitted.

The base station may transmit a unicast PDSCH to one or more terminals. Each terminal may receive a unicast PDSCH distinguished from each other from the base station. One or more terminals receiving the unicast PDSCH from the base station may return a HARQ response through the PUCCH resource indicated through the corresponding DCI.

The base station may transmit a multicast PDSCH to one or more terminals. One or more terminals may receive the same multicast PDSCH from the base station. One or more terminals receiving the same multicast PDSCH from the base station may return a HARQ response through the PUCCH resource indicated through the corresponding DCI.

Meanwhile, the base station may transmit both the unicast PDSCH and the multicast PDSCH. In this case, each terminal may receive any one type of PDSCH from the base station to the unicast PDSCH and the multicast PDSCH, or may receive both the unicast PDSCH and the multicast PDSCH. Upon receiving the PDSCH of any one type among the unicast PDSCH and the multicast PDSCH from the base station, the UE may return an HARQ response through the PUCCH resource indicated through the corresponding DCI.

If the terminal receives both the unicast PDSCH and the multicast PDSCH, the terminal returns a HARQ response for the unicast PDSCH through the PUCCH resource indicated by the DCI for the unicast PDSCH, and the DCI for the multicast PDSCH indicates A HARQ response for the multicast PDSCH may be returned through the PUCCH resource. Here, if the timing of the PUCCH resource indicated by the DCI for the unicast PDSCH and the PUCCH resource indicated by the DCI for the multicast PDSCH are the same, the UE unicast through the PUCCH resource indicated by the DCI for the unicast PDSCH. Both the HARQ responses for the PDSCH and the multicast PDSCH may be returned. For this, a PUCCH or HARQ response of a separate format may be defined and used. Here, if the terminal has been instructed in advance by the second feedback method or the third feedback method as the HARQ response method to the multicast PDSCH, the terminal uses the multicast PDSCH based on the first feedback method instead of the second or third feedback method. It is possible to generate a feedback signal for For example, when the UE wants to reply the unicast PDSCH and the multicast PDSCH through the same PUCCH resource in a situation where the NACK-only HARQ method is instructed as the HARQ response method for the multicast PDSCH, each of the unicast PDSCH and the multicast PDSCH The HARQ codebook may be generated so that all HARQ responses to the ACK/NACK HARQ feedback method are performed according to the ACK/NACK HARQ feedback scheme. The UE may return an ACK response or a NACK response to the unicast PDSCH and an ACK response or a NACK response to the multicast PDSCH to the base station based on the generated HARQ codebook.

In step S610 of FIG. 6 , the second communication node 602 performs the feedback operation and multi-function for the unicast PDSCH according to at least some of the first to seventh embodiments of the method by which the first communication node 601 transmits and receives a feedback signal. First configuration information instructing to perform a feedback operation for the cast PDSCH separately from each other may be generated (S610). For example, the second communication node 602 includes the configuration information of the first PUCCH format for the feedback operation for the unicast PDSCH, and the configuration information of the second PUCCH format for the feedback operation for the multicast PDSCH. information can be generated. Here, the configuration information of the first PUCCH format and the configuration information of the second PUCCH format may be configured based on the third embodiment of the method for transmitting and receiving a feedback signal. The second communication node 602 may transmit the first setting information generated in step S610 to the first communication node 601 . The first communication node 601 may receive first setting information for a feedback operation from the second communication node 602 ( S615 ).

The second communication node 602 may generate one or more control signals for scheduling one or more signals to be transmitted to the first communication node 601 ( S620 ). In an embodiment of the communication system, one or more signals to be transmitted by the second communication node 602 to the first communication node 601 may correspond to one or more downlink data or one or more PDSCHs. One or more control signals generated by the second communication node 602 in step S620 may correspond to one or more DCIs for scheduling one or more PDSCHs. The one or more DCIs generated in step S620 may be generated based on at least some of the first to seventh embodiments of the feedback signal transmission/reception method described above by the first communication node 601 and the second communication node 602. . The second communication node 602 may transmit one or more DCIs generated in step S620 to the first communication node 601 ( S625 ). The first communication node 601 may receive one or more DCIs transmitted from the second communication node 602 (S625).

The second communication node 602 may transmit one or more signals to the first communication node 601 based on the one or more control signals transmitted in step S625 ( S630 ). In one embodiment of the communication system, the first communication node 601 may receive one or more signals transmitted from the second communication node 602, based on one or more control signals received in step S625 (S630). . In one embodiment of the communication system, one or more signals transmitted from the second communication node 602 to the first communication node 601 may correspond to one or more PDSCHs transmitted by the base station to the terminal. Each of the one or more signals transmitted from the second communication node 602 to the first communication node 601 is a PDSCH (hereinafter unicast PDSCH) transmitted according to a unicast transmission method from the base station or a multicast transmission method from the base station. It may correspond to any one of the transmitted PDSCH (hereinafter, multicast PDSCH). However, this is only an example for convenience of description, and the embodiment of the present invention is not limited thereto.

The first communication node 601 may check whether each of the one or more signals transmitted from the second communication node 602 has been normally received ( S640 ). For example, the first communication node 601 may attempt to decode one or more signals transmitted from the second communication node 602 . Here, the first communication node 601 may determine that the decoded signal is normally received. On the other hand, the first communication node 601 may determine that a signal that has failed to be decoded is not normally received.

The first communication node 601 may check the feedback method set for itself (S650). For example, in an embodiment of the communication system, any one of the first to fourth feedback schemes described with reference to the first embodiment of the feedback signal transmission/reception method may be set in the first communication node 601 . The first communication node 601 may check the feedback method indicated by the second communication node 602 according to the same or similar method as described with reference to the second embodiment of the feedback signal transmission/reception method. For example, the second communication node 602 may provide first to fourth feedbacks to the first communication node 601 through an RRC message for controlling the first configuration information, one or more DCIs, and/or one or more PDSCH scheduling information. Any one of the methods can be set. If it is determined that the first feedback method (ie, ACK/NACK HARQ method) is set in the first communication node 601 , the first communication node 601 , an ACK signal indicating whether normal reception is confirmed in step S640 . Alternatively, it may be determined that a reply of the NACK signal is necessary. If it is confirmed that the second feedback method (ie, NACK-only HARQ method) is set in the first communication node 601 , the first communication node 601 responds to the signal confirmed not to be normally received in step S640 . However, it can be determined that a reply of the NACK signal is necessary. If it is confirmed that the third feedback method (ie, ACK-only HARQ method) is set in the first communication node 601 , the first communication node 601 only responds to the signal confirmed to be normally received in step S640 . It may be determined that a reply of the ACK signal is necessary. If it is confirmed that the fourth feedback method (ie, No-HARQ method) is set in the first communication node 601, the first communication node 601 may determine that there is no need to reply a separate HARQ response. have. However, this is only an example for convenience of description, and the embodiment of the present invention is not limited thereto.

If it is determined that it is not necessary to return the feedback signal to the second communication node 602 according to the verification result in steps S640 and S650, the first communication node 601 terminates the feedback procedure without a separate operation. can On the other hand, if it is determined that it is necessary to return the feedback signal to the second communication node 602 according to the verification result in steps S640 and S650, the first communication node 601 is S615 for the feedback signal. It is possible to check the information of each of the one or more control signals received in the step. For example, when the first communication node 601 determines that it is necessary to return a feedback signal for one or more PDSCHs in steps S640 and S650, one or more DCI corresponding to one or more PDSCHs identified as requiring a reply of a feedback signal. One or more pieces of information included in each may be checked (S660).

Specifically, the first communication node 601 checks the information of the PUCCH resource allocated through the DCI transmitted in advance to schedule each PDSCH for the HARQ response to one or more PDSCHs requiring a feedback signal to be returned. can Here, the PUCCH resource information is the PUCCH resource allocated to the first communication node 601 by the second communication node 602 according to the same or similar method as described with reference to the third embodiment of the feedback signal transmission/reception method. can mean

Meanwhile, the first communication node 601 checks information of one or more fields included in each DCI transmitted to the first communication node 601 for the scheduling of the PDSCH before the second communication node 602 transmits the PDSCH. can Each DCI may include some or all of an NDI field, an HPN field, and a DAI field. Here, the information of the NDI field may be set according to the same or similar method as described with reference to the fourth embodiment of the method for transmitting and receiving a feedback signal. The information in the HPN field may be set in the same or similar manner as described with reference to the fifth embodiment of the feedback signal transmission/reception method. The information of the DAI field may be set in the same or similar manner as described with reference to the sixth embodiment of the feedback signal transmission/reception method.

The first communication node 601 may generate one or more feedback signals with respect to one or more signals transmitted from the second communication node 602 according to the result of the verification operations according to steps S640 to S660 (S670). The first communication node 601 may return one or more generated feedback signals to the second communication node 602 (S675). For example, the first communication node 601, according to the result of the confirmation operations according to steps S640 to S660, one or more HARQs for one or more PDSCHs identified as requiring a reply of a feedback signal among one or more PDSCHs received in step S630. You can create a response. The first communication node 601 may return one or more HARQ responses generated in step S670 to the second communication node 602 based on one or more PUCCH resources indicated by one or more DCIs received in step S625. Here, the first communication node 601 transmits the signal transmitted from the second communication node 602 to the second communication node 602 according to whether the signal transmitted according to the unicast transmission method or the multicast transmission method is transmitted. A feedback signal may be returned. For example, the first communication node 601 generates a feedback signal or transmits the generated feedback signal to the second communication according to the same or similar method as described with reference to at least some of the first to seventh embodiments of the method for transmitting and receiving a feedback signal. It may reply to node 602 . The second communication node 602 monitors one or more PUCCH resources indicated by one or more DCIs transmitted in step S625, and may receive one or more feedback signals returned from the first communication node 601 (S675). The second communication node 602 may determine whether a retransmission operation for the first communication node 601 is necessary based on the returned one or more feedback signals. For example, when the second communication node 602 receives one or more NACK signals from the first communication node 601 , one or more PDSCHs corresponding to the received one or more NACK signals are retransmitted to the first communication node 601 . can

The first communication node 601 and the second communication node 602 may perform a mutual feedback procedure based on the same or similar operations to steps S610 to S675. The first communication node 601 transmits the unicast PDSCH and/or the second communication node 602 to the first communication node 601 and/or the first node group including the first communication node 601 . A feedback operation for the multicast PDSCH may be performed. The second communication node 602 receives a feedback signal for the unicast PDSCH and/or multicast PDSCH transmitted to the first terminal group including the first communication node 601 and/or the first communication node 601 . can receive The second communication node 602 may transmit, in addition to the first communication node 601 and/or the first group of nodes, the unicast PDSCH and/or the multicast PDSCH to one or more other communication nodes and/or one or more other node groups. can The second communication node 602 may receive a feedback signal for the PDSCH transmitted to a plurality of communication nodes and/or a plurality of node groups. The second communication node 602 may perform a feedback procedure with a plurality of communication nodes and/or a plurality of node groups based on the same or similar configurations as those described with reference to FIG. 6 .

According to an embodiment of the present invention, when the base station transmits downlink data to the terminal, either a unicast transmission method or a multicast transmission method may be used, or a unicast transmission method or multicast transmission method All methods can be used. The base station may instruct the terminal to provide information for the terminal to perform a feedback operation on downlink data transmitted according to the unicast transmission method or the multicast transmission method through DCI for scheduling downlink data to be transmitted to the terminal. have. Accordingly, a feedback operation between the base station and the terminal supporting both the unicast transmission method and the multicast transmission method can be efficiently performed.

However, effects that can be achieved by the method and apparatus for transmitting and receiving a feedback signal in a communication system according to embodiments of the present invention are not limited to those mentioned above, and other effects not mentioned are described in the specification of the present application. It will be clearly understood by those of ordinary skill in the art to which the present invention pertains from the described configurations.

The methods according to the present invention may be implemented in the form of program instructions that can be executed by various computer means and recorded in a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, etc. alone or in combination. The program instructions recorded on the computer-readable medium may be specially designed and configured for the present invention, or may be known and available to those skilled in the art of computer software.

Examples of computer-readable media include hardware devices specially configured to store and carry out program instructions, such as ROM, RAM, flash memory, and the like. Examples of program instructions include not only machine language codes such as those generated by a compiler, but also high-level language codes that can be executed by a computer using an interpreter or the like. The hardware device described above may be configured to operate as at least one software module to perform the operations of the present invention, and vice versa.

Although it has been described with reference to the above embodiments, it will be understood by those skilled in the art 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. will be able

Claims (20)

A method for transmitting a feedback signal performed by a first terminal of a communication system, the method comprising:
From the first base station of the communication system, configuration information of a first physical uplink control channel (PUCCH) format for feedback on unicast transmission and feedback on multicast transmission Receiving first configuration information including configuration information of a second PUCCH format for;
receiving, from the first base station, first DL control information (DCI) for scheduling first DL data;
receiving, from the first base station, the first DL data based on the first configuration information and the first DCI; and
performing, with the first base station, a feedback operation on the first DL data based on the first configuration information and the first DCI;
Receiving the first DCI and performing a feedback operation on the first DL data may include a case in which the first DL data is DL data transmitted according to the unicast transmission method and in the multicast transmission method. A method for transmitting a feedback signal, characterized in that it is performed in a different way in the case of DL data transmitted according to the DL data. The method according to claim 1,
The step of performing the feedback operation on the first DL data includes:
When the first DL data is DL data transmitted according to the multicast transmission scheme, the first DCI allocates the first DL data to each of the plurality of terminals included in the first terminal group including the first terminal. checking information on a first PUCCH RB allocated to the first terminal among a plurality of physical uplink control channel (PUCCH) resource blocks; and
and transmitting a first feedback signal for the first DL data to the first base station through the first PUCCH RB. 3. The method according to claim 2,
The second PUCCH format is,
A method for transmitting a feedback signal, characterized in that it is defined to include a first information element (IE) indicating that the PUCCH is allocated to a plurality of RBs. The method according to claim 1,
The step of performing the feedback operation on the first DL data includes:
When the first DL data is DL data transmitted according to the multicast transmission scheme, the first terminal group including the first terminal is divided for each of the plurality of subgroups by the first DCI. checking information on a first PUCCH resource allocated to a first subgroup including the first terminal among a plurality of PUCCH resources; and
and transmitting a first feedback signal for the first DL data to the first base station through the first PUCCH resource. The method according to claim 1,
Receiving the first DCI comprises:
Based on the DCI format of the first DCI or the type of a radio network temporary identifier (RNTI) that scrambles a cyclic redundancy check (CRC) of the first DCI, a new data indicator (NDI) field of the first DCI is the uni and determining whether to indicate whether DL data transmitted according to the cast transmission method is initially transmitted or whether data transmitted according to the multicast transmission method is initially transmitted. How to send a feedback signal. The method according to claim 1,
Receiving the first DCI comprises:
Based on the HPN value indicated by the HPN field of the first DCI, the HPN field indicates information related to a hybrid automatic repeat request (HARQ) process of DL data transmitted according to the unicast transmission scheme, or the Including the step of checking whether information related to the HARQ process of the DL data transmitted according to the multicast transmission method is indicated,
Among the N HPN values that the HPN field may indicate, n HPN values are used to indicate information related to the HARQ process of DL data transmitted according to the unicast transmission method, and the remaining (Nn) HPN values are A method for transmitting a feedback signal, which is used to indicate information related to an HARQ process of DL data transmitted according to a multicast transmission method. The method according to claim 1,
Receiving the first DCI comprises:
When the first DL data is DL data transmitted according to the multicast transmission scheme, the unicast up to a time point at which the first DL data is scheduled through a value of a downlink assignment index (DAI) field of the first DCI A method for transmitting a feedback signal, comprising: acquiring a counter-DAI value and a total-DAI value in which a DL data scheduling result according to a transmission method and a DL data scheduling result according to the multicast transmission method are reflected. The method according to claim 1,
The first DCI is characterized in that, when the first DL data is DL data transmitted according to the multicast transmission method, it corresponds to a DCI defined not to include a DAI field. The method according to claim 1,
The first DL data corresponds to DL data transmitted according to the unicast transmission method,
The method of transmitting the feedback signal,
receiving, from the first base station, a second DCI for scheduling second DL data to be transmitted according to the multicast transmission scheme;
receiving, from the first base station, the second DL data based on the first configuration information and the second DCI; and
performing, with the first base station, a feedback operation on the second DL data based on the first configuration information and the second DCI,
The first PUCCH resource indicated by the first DCI for a feedback procedure for the first DL data transmitted according to the unicast transmission method and the second DL data in which the second DCI is transmitted according to the multicast transmission method When the timing of the second PUCCH resource indicated for the feedback procedure for ? is the same, both the feedback operation for the first DL data and the feedback operation for the second DL data are performed through the first PUCCH resource. A method for transmitting a feedback signal. 10. The method of claim 9,
The step of performing a feedback operation on the second DL data includes:
When the first terminal is instructed to use a NACK-only HARQ method as a feedback method for performing a feedback procedure for DL data transmitted according to the multicast transmission method, ACK/NACK other than the indicated NACK-only HARQ method A method for transmitting a feedback signal, characterized in that a feedback operation is performed on the second DL data according to a HARQ scheme. The method according to claim 1,
The step of performing the feedback operation on the first DL data includes:
When the first DL data is DL data transmitted according to the multicast transmission scheme, the first feedback scheme indicated prior to transmission of the first DL data from the first base station and whether the first DL data is normally received determining whether a feedback signal for the first DL data needs to be returned based on
generating a first feedback signal for the first DL data when it is necessary to return a feedback signal for the first DL data; and
transmitting the first feedback signal to the first base station;
The first feedback scheme is an ACK/NACK HARQ scheme, a NACK-only HARQ scheme, through a radio resource control (RRC) message for controlling the first configuration information, the first DCI, or scheduling information of the first DL data. , characterized in that the ACK-only HARQ scheme and the No-HARQ scheme are selectively indicated, the feedback signal transmission method. A method for receiving a feedback signal performed by a first base station of a communication system, the method comprising:
To a plurality of terminals of the communication system, configuration information of a first physical uplink control channel (PUCCH) format for feedback on unicast transmission and feedback on multicast transmission transmitting first configuration information including configuration information of a second PUCCH format for
transmitting first DL control information (DL control information, DCI) for scheduling first DL data to at least one of the plurality of terminals of the communication system;
transmitting the first DL data to the at least one terminal based on the first configuration information and the first DCI; and
Receiving at least one feedback signal for the first DL data from the at least one terminal based on the first configuration information and the first DCI,
Transmitting the first DCI and receiving the at least one feedback signal may include a case in which the first DL data is DL data transmitted according to the unicast transmission method and is transmitted according to the multicast transmission method. In the case of DL data, the feedback signal receiving method, characterized in that it is performed in different ways. 13. The method of claim 12,
In the first DCI, when the first DL data is DL data transmitted according to the multicast transmission scheme, a plurality of PUCCH resource blocks (RBs) are included in the first terminal group of the communication system. It is configured to be allocated separately from each other for each of the terminals of
Receiving the at least one feedback signal comprises:
identifying the plurality of PUCCH RBs allocated based on the first DCI; and
Receiving the at least one feedback signal for the first DL data from at least some of the plurality of terminals included in the first terminal group through at least some PUCCH RBs of the plurality of PUCCH RBs A method for receiving a feedback signal, comprising the steps of. 13. The method of claim 12,
The second PUCCH format is,
A method for receiving a feedback signal, characterized in that it is defined to include a first information element (IE) indicating that the PUCCH is allocated to a plurality of RBs. 13. The method of claim 12,
DCI for scheduling DL data transmitted according to the unicast transmission method and DCI for scheduling DL data transmitted according to the multicast transmission method are configured based on different DCI formats,
The method for receiving a feedback signal, characterized in that the first base station independently operates a new data indicator (NDI) field of DCIs configured based on different DCI formats. 13. The method of claim 12,
The first base station, in DCI scheduling DL data transmitted according to the unicast transmission method or DL data transmitted according to the multicast transmission method, N HPNs that can be indicated by a HARQ process number (HPN) field Among the values, n HPN values are used to indicate information related to a hybrid automatic repeat request (HARQ) process of DL data transmitted according to the unicast transmission scheme, and the remaining Nn HPN values are used according to the multicast transmission scheme. A method for receiving a feedback signal, characterized in that it is used to indicate information related to the HARQ process of transmitted DL data. 13. The method of claim 12,
The first base station operates a DCI for scheduling DL data transmitted according to the unicast transmission method and an HPN field of a DCI for scheduling DL data transmitted according to the multicast transmission method independently of each other, characterized in that , how to receive a feedback signal. 13. The method of claim 12,
Transmitting the first DCI comprises:
When the first DL data is DL data transmitted according to the multicast transmission method, a DL data scheduling result according to the unicast transmission method and DL according to the multicast transmission method up to a time point when the first DL data is scheduled checking a data scheduling result; and
Counter-DAI value and total- of the DAI (Downlink assignment index) field of the first DCI by reflecting both the DL data scheduling result according to the unicast transmission method and the DL data scheduling result according to the multicast transmission method A method for receiving a feedback signal comprising the step of determining a DAI value. 13. The method of claim 12,
The first DL data corresponds to DL data transmitted to the first terminal of the communication system according to the unicast transmission method,
The method of receiving the feedback signal,
transmitting, to a first terminal group including the first terminal, a second DCI for scheduling second DL data transmitted according to the multicast transmission scheme;
transmitting the second DL data to a plurality of terminals included in the first terminal group based on the first configuration information and the second DCI; and
Receiving at least one feedback signal for the second DL data from at least some of the plurality of terminals included in the first terminal group based on the first configuration information and the second DCI; including more,
The first PUCCH resource indicated by the first DCI for a feedback procedure for the first DL data transmitted according to the unicast transmission method and the second DL data in which the second DCI is transmitted according to the multicast transmission method When the timing of the second PUCCH resource indicated for the feedback procedure for . A method for receiving a feedback signal, characterized in that it becomes. 13. The method of claim 12,
Prior to transmitting the plurality of DL data to the plurality of terminal groups of the communication system according to the multicast transmission scheme, the first base station has the first configuration information and a plurality of DCI for scheduling each of the plurality of DL data , and a plurality of RRC (radio resource control) messages for controlling scheduling information of the plurality of DL data indicate a feedback scheme for the plurality of terminal groups,
The feedback scheme is selected from among an ACK/NACK HARQ scheme, a NACK-only HARQ scheme, an ACK-only HARQ scheme, and a No-HARQ scheme, and is independently indicated for each of the plurality of terminal groups or the plurality of terminal groups A method for receiving a feedback signal, characterized in that the same is indicated for at least two or more groups of terminals.

Images