KR102462601B1 - Method and apparatus for transmitting and receiving signal through frequency bands in communication system - Google Patents

Abstract

Disclosed are a method and apparatus for transmitting and receiving a signal through frequency bands in a communication system. The signal transmission method performed by the communication node #1 is for TBs #0 to #(n-2) and TBs #0 to #(n-2) transmitted to FAs #0 to #(n-2). Generating TB control information, generating NC-TB transmitted to FA #(n-1) and NC-TB control information for the NC-TB, the FA #0 to #(n-2) Transmitting the TB control information and the TB #0 to #(n-2) through, and transmitting the NC-TB control information and the NC-TB through the FA #(n-1) do. Accordingly, the performance of the communication system may be improved.

Description

Method and apparatus for transmitting and receiving a signal through frequency bands in a communication system

The present invention relates to a technology for transmitting and receiving signals in a communication system supporting the requirements of low delay and high reliability, and more particularly, to a technology for transmitting and receiving signals to which network coding is applied through a plurality of frequency bands.

4G (4th Generation) communication system (e.g., LTE (Long Term Evolution) communication system, LTE-A (Advanced) communication system) for the processing of rapidly increasing wireless data after the commercialization of the frequency band of the 4G communication system ( For example, a 5G (5th Generation) communication system (for example, NR (New Radio) communication system) is being considered. The 5G communication system may support enhanced Mobile BroadBand (eMBB), Ultra-Reliable and Low Latency Communication (URLLC), and massive Machine Type Communication (mMTC).

In a 5G communication system, communication nodes (eg, a base station, a terminal) may perform communication using a millimeter WAVE (mmWAVE) band. The mmWAVE band used in the 5G communication system may consist of a plurality of frequency alignments (FAs), and the FA may indicate a frequency band having a narrow bandwidth.

The transmitting communication node may transmit different transport blocks (TBs) in a specific subframe of a plurality of FAs. If the probability of successfully receiving one TB through one FA at the receiving communication node is P _e , the probability of successfully receiving all TBs through n FAs at the receiving communication node may be (P _e ) ⁿ . If P _e is 0.9, the probability ((P _e ) ⁿ ) of successfully receiving all TBs (eg, two TBs) through two FAs may be 0.81. That is, as the number of FAs used for communication increases, the probability of successfully receiving all TBs may decrease. In addition, the radio link control (RLC) layer of the receiving communication node may not forward the data packet to the upper layer until the TB in which the error occurred is successfully received to ensure sequential transmission of the data packet. Accordingly, the transmission delay of the data packet may increase.

An object of the present invention for solving the above problems is to provide a method and apparatus for transmitting and receiving signals to which network coding is applied through frequency alignments (FAs) in a communication system.

The signal transmission method performed by the communication node #1 according to the first embodiment of the present invention for achieving the above object is, TB #0 to #(n-2) transmitted to FAs #0 to #(n-2) ) and generating TB control information for the TBs #0 to #(n-2), generating NC-TB transmitted to FA #(n-1) and NC-TB control information for the NC-TB transmitting the TB control information and the TBs #0 to #(n-2) through the FAs #0 to #(n-2), and the NC through the FA #(n-1) -transmitting TB control information and the NC-TB, wherein the NC-TB is generated by performing network coding on the TBs #0 to #(n-2), wherein n is an integer of 3 or more .

Here, the signal transmission method includes receiving HARQ responses for the TBs #0 to #(n-2) and the NC-TB from communication node #2, and the HARQ response for the NC-TB is ACK and, when the HARQ response for one TB among the TBs #0 to #(n-2) is NACK, without performing a retransmission procedure for the one TB, the FAs #0 to #(n-1) The method may further include performing a supertransmission procedure for (n-1) new TBs using .

Here, the signal transmission method includes receiving HARQ responses for the TBs #0 to #(n-2) and the NC-TB from communication node #2, and the HARQ response for the NC-TB is NACK and, if the HARQ response to s TBs among the TBs #0 to #(n-2) is NACK, and the s is 1 or more, the s using the FAs #0 to #(n-1) The method may further include performing a retransmission procedure for a TB and a supertransmission procedure for (n-1-s) new TBs.

Here, the signal transmission method includes receiving HARQ responses for the TBs #0 to #(n-2) and the NC-TB from communication node #2, and the HARQ response for the NC-TB is ACK and, when the HARQ response to s TBs among the TBs #0 to #(n-2) is NACK, and the s is an integer of 2 or more, the s using the FAs #0 to #(n-1) The method may further include performing a retransmission procedure for (s-1) TBs among TBs and a supertransmission procedure for (n-1-(s-1)) new TBs.

Here, the NC-TB control information indicates an NC flag indicating that the NC-TB is transmitted, and an index of an FA through which the TBs #0 to #(n-2) constituting the NC-TB are transmitted. It may include an FA index list and a HARQ process ID list indicating the HARQ process ID of each of the TBs #0 to #(n-2) constituting the NC-TB.

Here, each of the FAs #0 to #(n-1) is set to a different frequency band, and the FAs #0 to #(n-1) may belong to the entire frequency band of the communication system.

Here, the TB control information, the TBs #0 to #(n-2), the NC-TB control information, and the NC-TB may be transmitted through the same subframe.

Here, the network coding may be an XOR operation.

In the signal reception method performed by the communication node #1 according to the second embodiment of the present invention for achieving the above object, TBs #0 to #(n-2) in FAs #0 to #(n-2) are Receiving the TB control information and the TB #0 to #(n-2) from the communication node #2, the NC-TB control information for the NC-TB in FA #(n-1) and the NC-TB Receiving from the communication node #2, and HARQ responses for the TBs #0 to #(n-1) and the NC-TB through the FAs #0 to #(n-1), the communication node #2 and transmitting to , wherein the NC-TB is generated by performing network coding on the TBs #0 to #(n-2), where n is an integer of 3 or more.

Here, in the signal reception method, when the HARQ response to the NC-TB is ACK, and the HARQ response to one TB among TB #0 to #(n-2) is NACK, the TB #0 to #(n-2) may further include recovering the one TB by performing network decoding between the NC-TB and the remaining TBs except for the one TB, wherein the network decoding may be an XOR operation. have.

Here, in the signal reception method, when a retransmission TB exists among the TBs #0 to #(n-2), network decoding between the retransmission TB and the NC-TB' stored in the buffer of the communication node #1 is performed. The method may further include the step, wherein the NC-TB' may be received from the communication node #2 before the reception of the NC-TB.

Here, in the signal reception method, the HARQ response to the NC-TB is ACK, the HARQ response to s TBs among the TBs #0 to #(n-2) is NACK, and the s is 2 or more If it is an integer, performing network decoding between the NC-TBs and the remaining TBs except for the s TBs among the TBs #0 to #(n-2), and storing the result of the network decoding in the buffer of the communication node #1 It may further include the step of storing to.

Here, in the step of storing in the buffer of the communication node #1, the HARQ process ID of the s number of TBs together with the result of the network decoding may be stored in the buffer of the communication node #1.

Here, the signal reception method includes the steps of re-receiving (s-1) TBs from the communication node #2 among the s TBs in the FAs #0 to #(n-1), and the (s-1) ) TBs and the network decoding result stored in the buffer by performing network decoding, the method may further include recovering the remaining TBs except for the (s-1) TBs among the s TBs.

Here, the NC-TB control information indicates an NC flag indicating that the NC-TB is transmitted, and an index of an FA through which the TBs #0 to #(n-2) constituting the NC-TB are transmitted. It may include an FA index list and a HARQ process ID list indicating the HARQ process ID of each of the TBs #0 to #(n-2) constituting the NC-TB.

Communication node #1 according to a third embodiment of the present invention for achieving the above object includes a processor and a memory in which at least one instruction executed by the processor is stored, and the at least one instruction is, FA #0 to Receive TB control information for TBs #0 to #(n-2) and TBs #0 to #(n-2) in #(n-2) from communication node #2, and FA #(n-1) Receives the NC-TB control information and the NC-TB for the NC-TB from the communication node #2, and receives the TB #0 to #(n-1) and the HARQ response for the NC-TB in the FA is executed to transmit to the communication node #2 through #0 to #(n-1), and the NC-TB is generated by performing network coding on the TBs #0 to #(n-2), wherein the n is an integer greater than or equal to 3;

Here, in the at least one command, when the HARQ response to the NC-TB is ACK, and the HARQ response to one TB among TB #0 to #(n-2) is NACK, the TB # It may be further executed to recover the one TB by performing network decoding between the NC-TB and the remaining TBs except for the one TB among 0 to #(n-2), and the network decoding may be an XOR operation.

Here, when the retransmission TB exists among the TBs #0 to #(n-2), the at least one command performs network decoding between the retransmission TB and the NC-TB' stored in the buffer of the communication node #1. and the NC-TB' may be received from the communication node #2 before the reception of the NC-TB.

Here, in the at least one command, the HARQ response to the NC-TB is ACK, the HARQ response to s TBs among the TBs #0 to #(n-2) is NACK, and the s is 2 In the case of an integer greater than or equal to, the network decoding is performed between the remaining TBs except for the s TBs among the TB #0 to TB #(n-2) and the NC-TB, and the result of the network decoding is displayed in the communication node #1. It can be further executed to store in a buffer.

Here, the at least one command re-receives (s-1) TBs from the communication node #2 among the s TBs in the FAs #0 to #(n-1), and the (s-1) ) TBs and the network decoding result stored in the buffer, thereby recovering the remaining TBs excluding the (s-1) TBs among the s TBs.

According to the present invention, when the frequency band is composed of n frequency alignments (FAs) (eg, FA #0 to #(n-1)), the transmitting communication node is configured to FA #0 to #(n-2). ) can transmit (n-1) transport blocks (TBs) through a specific subframe of It can be transmitted through a specific subframe of #(n-1).

In this case, even when one or more TBs among (n-1) TBs are not successfully received at the receiving communication node, the receiving communication node may recover the TBs that have not been successfully received based on the NC-TB. Accordingly, when the NC-TB is used, the probability that all TBs are successfully received in the plurality of FAs may increase, and accordingly, the transmission delay of the data packet may be reduced.

1 is a conceptual diagram illustrating a first embodiment of a communication system.
2 is a block diagram showing a first embodiment of a communication node constituting a communication system.
3 is a conceptual diagram illustrating a first embodiment of a method for transmitting and receiving signals through FAs in a communication system.
4 is a conceptual diagram illustrating a first embodiment of a TB transmission/reception method based on a network coding scheme in a communication system.
5 is a flowchart illustrating a second embodiment of a TB transmission/reception method based on a network coding scheme in a communication system.
6 is a flowchart illustrating a third embodiment of a TB transmission/reception method based on a network coding scheme in a communication system.
7 is a flowchart illustrating a fourth embodiment of a TB transmission/reception method based on a network coding scheme in a communication system.
8 is a flowchart illustrating a first embodiment of a method for transmitting a TB based on a network coding scheme in a communication system.
9A is a flowchart illustrating a first embodiment of a method for receiving a TB based on a network coding scheme in a communication system.
9B is a flowchart illustrating a second embodiment of a method for receiving a TB based on a network coding scheme 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 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 a component is referred to as being “connected” or “connected” to another component, it may be directly connected or connected to the other component, but it is understood that other components 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 is to be understood that this does not preclude the possibility of the presence or addition of numbers, steps, operations, components, parts, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or 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

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.

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 contents 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 meaning as a communication network (network).

1 is a conceptual diagram illustrating a first 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 are 4G communication (eg, long term evolution (LTE), LTE-A (advanced)) defined in 3GPP (3rd generation partnership project) standard, 5G communication (eg, NR (new radio)) ) 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), a mobility management entity (MME), and the like. 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-) constituting the communication system 100 4, 130-5, 130-6) may each have the following structure.

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

Referring to FIG. 2 , the communication node 200 may include at least one processor 210 , a memory 220 , and a 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, and 120-2 is a NodeB (NodeB), an advanced NodeB (evolved NodeB), gNB, and a base transceiver station (BTS). ), a radio base station, a radio transceiver, an access point, an access node, and the like. Each of the plurality of terminals 130-1, 130-2, 130-3, 130-4, 130-5, 130-6 includes a user equipment (UE), a terminal, an access terminal, and a mobile terminal. It may be referred to as a mobile terminal, a station, a subscriber station, a mobile station, a portable subscriber station, a node, a device, and the like.

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 the 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 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 method, 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. A plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) each of the terminals (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, methods for transmitting and receiving signals to which network coding is applied through frequency alignments (FAs) 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 second communication node corresponding thereto 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.

3 is a conceptual diagram illustrating a first embodiment of a method for transmitting and receiving signals through FAs in a communication system.

Referring to FIG. 3 , the communication system may include a communication node #1 310 , a communication node #2 320 , and the like. The communication system may support at least one of 4G communication and 5G communication, and communication node #1 310 sends data packets P #i, P #(i+1), P #( i+2), P #(i+3), etc.) may operate as a transmitting communication node, and communication node #2 (320) receives data packets (P #i, P) from communication node #1 (310). #(i+1), P #(i+2), P #(i+3), etc.) may operate as a receiving communication node. Each of the communication nodes 310 and 320 may be a base station, a terminal, etc. shown in FIG. 1 . Alternatively, each of the communication nodes 310 and 320 is a communication node (eg, a hub) constituting a backhaul network, an Xhaul network, a fronthaul network, or a midhaul network. hub), a terminal, an Xhaul distributed unit (XDU), an Xhaul control unit (XCU), etc.). In addition, each of the communication nodes 310 and 320 may be configured the same as or similarly to the communication node 200 shown in FIG. 2 , a physical (PHY) layer, a medium access control (MAC) layer, and a radio link (RLC). control) layer and the like.

Communication between communication node #1 310 and communication node #2 320 may be performed using n FAs. n may be an integer of 2 or more. Each of the FAs may indicate one frequency band and may be set to a narrow frequency band. For example, the entire frequency band of the communication system may be composed of n FAs.

When a data packet (P #i, P #(i+1), P #(i+2), P #(i+3), etc.) to be transmitted to communication node #2 320 exists in the buffer, communication Node #1 310 may generate a transport block (TB) to be transmitted to each of the FAs by using the data packet existing in the buffer. i may be an integer greater than or equal to 0. For example, communication node #1 310 may generate TB #0 to be transmitted via FA #0, may generate TB #1 to be transmitted via FA #1, and FA #(n-2). ) may generate TB #(n-2) to be transmitted, and TB #(n-1) to be transmitted through FA #(n-1) may be generated.

In addition, communication node #1 310 controls information (eg, resource allocation information, modulation and coding scheme (MCS) level, hybrid automatic repeat request (HARQ) process ID (identifier) for each of the TBs) etc) can be created. Control information for a TB may be referred to as “TB control information”. For example, the resource allocation information for TB #0 may indicate a data channel (ie, time-frequency resources in which TB #0 is transmitted) belonging to subframe #m of FA #0, and of TB #0 The HARQ process ID may be set to #0. The resource allocation information for TB #1 may indicate a data channel (ie, time-frequency resources in which TB #1 is transmitted) belonging to subframe #m of FA #1, and the HARQ process ID of TB #1 is It can be set to #1. Resource allocation information for TB #(n-2) indicates a data channel (ie, time-frequency resources through which TB #(n-2) is transmitted) belonging to subframe #m of FA #(n-2). and the HARQ process ID of TB #(n-2) may be set to #(n-2). Resource allocation information for TB #(n-1) indicates a data channel (ie, time-frequency resources through which TB #(n-1) is transmitted) belonging to subframe #m of FA #(n-1) and the HARQ process ID of TB #(n-1) may be set to #(n-1). m may be an integer greater than or equal to 0.

Communication Node #1 310 may transmit control information and TBs using FAs. For example, communication node #1 310 may transmit control information for TB #0 and TB #0 in subframe #m of FA #0, and transmit TB #1 in subframe #m of FA #1. It is possible to transmit control information and TB #1 for In subframe #m of #(n-1), control information for TB #(n-1) and TB #(n-1) may be transmitted.

On the other hand, communication node #2 320 may receive control information in subframe #m (eg, a control channel in subframe #m) of FA #0 to #(n-1), and TB #0 to #(n-1) may be received on the data channel indicated by The communication node #2 320 may identify a TB in which an error exists by performing demodulation/decoding operations on TBs #0 to #(n-1). For example, when an error exists in TB #0, communication node #2 320 may transmit a HARQ negative acknowledgment (NACK) for TB #0 to communication node #1 310 . The HARQ NACK for TB #0 may be transmitted through FA #0 and may include the HARQ process ID #0 of TB #0. When the HARQ NACK for TB #0 is received from communication node #2 320 , communication node #1 310 may retransmit TB #0. Retransmission TB #0 may be transmitted through FA #0.

If there is no error in TB #1, communication node #2 320 may transmit a HARQ ACK for TB #1 to communication node #1 310 . The HARQ ACK for TB #1 may be transmitted through FA #1 and may include the HARQ process ID #1 of TB #1. When the HARQ ACK for TB #1 is received from communication node #2 320 , communication node #1 310 may determine that TB #1 is successfully received from communication node #2 320 . In this case, the communication node #1 310 may delete TB #1 (eg, data packets constituting TB #1) from the buffer.

The MAC layer of communication node #2 (320) sends the MAC service data unit (SDU) constituting the successfully received TB (eg, TB in which no error exists) to the RLC layer of communication node #2 (320). can transmit The RLC layer of the communication node #2 320 may generate an RLC protocol data unit (PDU) based on the MAC SDU, and sequentially transmit the RLC PDU to an upper layer (eg, a packet data convergence packet (PCDP) layer). RLC PDUs may be sequentially arranged based on a sequence number (SN) included in the RLC PDU in order to be transmitted to . However, when an error TB is received, the RLC PDUs may not be sequentially arranged. In this case, the RLC layer of the communication node #2 320 may not deliver the RLC PDUs to the upper layer until the TB in which the error exists is re-received. For example, when RLC PDUs having SNs #0, #1, #2, and #5 are received but RLC PDUs having SNs #3 and #4 are not received, the RLC of communication node #2 320 The layer may not deliver the RLC PDU (eg, the RLC PDU with SN #5) to the higher layer until RLC PDUs having SNs #3 and #4 are received. Accordingly, the transmission delay of the data packet may increase.

Meanwhile, in the above-described communication system, the MCS level may be determined based on the reception success probability (P _e ) of the TB according to the HARQ operation. For example, when the MCS level is determined such that the signal to noise ratio (SNR) or the signal to interference plus noise ratio (SINR) is high, the reception success probability (P _e ) of the TB is improved, but more in order to transmit the same TB. A lot of radio resources may be required. The MCS level may be determined to satisfy "P _e = 0.9", and in this case, P _e may be 0.9 in each of FA #0 to #(n-1). However, the reception success probability of all TBs in FAs #0 to #(n-1) may be (P _e ) ⁿ .

When two FAs are used for communication between the communication node #1 310 and the communication node #2 320 , (P _e ) ⁿ may be 0.81 in all of the two FAs. When three FAs are used for communication between communication node #1 310 and communication node #2 320 , (P _e ) ⁿ may be 0.729 in all three FAs. When four FAs are used for communication between the communication node #1 310 and the communication node #2 320 , (P _e ) ⁿ may be 0.6561 in all of the four FAs. That is, as the number of FAs used for communication between the communication node #1 310 and the communication node #2 320 increases, (P _e ) ⁿ decreases, and accordingly, the retransmission probability of the TB may increase. Accordingly, the transmission delay of the data packet may increase, and the requirements of low delay and high reliability may not be satisfied in the communication system.

To solve these problems, the TB may be transmitted based on a network coding scheme.

4 is a conceptual diagram illustrating a first embodiment of a TB transmission/reception method based on a network coding scheme in a communication system.

Referring to FIG. 4 , a communication system may include a plurality of communication nodes 410 , 420 , 430 , 440 , 450 , 460 , 470 and 480 . Each of the plurality of communication nodes 410 , 420 , 430 , 440 , 450 , 460 , 470 , 480 may be configured the same as or similar to the communication node 200 illustrated in FIG. 2 . When the destination of TB #1 is communication nodes #7 and #8 (470, 480), communication node #1 (410) may transmit TB #1 to communication nodes #7 and #8 (470, 480). When the destination of TB #2 is communication nodes #7 and #8 (470, 480), communication node #2 (420) may transmit TB #2 to communication nodes #7 and #8 (470, 480).

For example, communication node #1 410 may transmit TB #1 to communication node #3 430 . Communication node #3 430 may receive TB #1 from communication node #1 410 and may transmit TB #1 to communication node #5 450 and communication node #7 470 . Also, communication node #2 420 may transmit TB #2 to communication node #4 440 . Communication node #4 440 may receive TB #2 from communication node #2 420 and may transmit TB #2 to communication node #5 450 and communication node #8 480 .

#2)를 생성할 수 있다. 예를 들어, 네트워크 코딩 절차에서 통신 노드 #5(450)는 TB #1(예를 들어, TB #1의 비트 스트림)과 TB #2(예를 들어, TB #2의 비트 스트림) 간의 XOR(exclusive OR)을 수행함으로써 NC-TB(예를 들어, TB #1

#2)를 생성할 수 있다. 통신 노드 #5(450)는 NC-TB를 통신 노드 #6(460)에 전송할 수 있다. 통신 노드 #6(460)은 통신 노드 #5(450)로부터 NC-TB를 수신할 수 있고, NC-TB를 통신 노드 #7 및 #8(470, 480)에 전송할 수 있다.Communication node #5 450 may receive TB #1 and TB #2, and apply network coding (NC)-TB (eg, TB #1) to TB #1 and TB #2.

#2) can be created. For example, in a network coding procedure, communication node #5 450 performs an XOR between TB #1 (eg, bitstream of TB#1) and TB #2 (eg, bitstream of TB#2) ( NC-TB (eg, TB #1) by performing an exclusive OR

#2) can be created. Communication node #5 450 may transmit the NC-TB to communication node #6 460 . Communication node #6 (460) may receive the NC-TB from communication node #5 (450) and may transmit the NC-TB to communication nodes #7 and #8 (470, 480).

Communication node #7 470 may receive TB #1 from communication node #3 430 and may receive an NC-TB from communication node #6 460 . In this case, communication node #7 470 may acquire TB #2 by performing network decoding (eg, XOR) between TB #1 and NC-TB. Also, communication node #8 480 may receive TB #2 from communication node #4 440 and may receive an NC-TB from communication node #6 460 . In this case, communication node #8 480 may obtain TB #1 by performing network decoding (eg, XOR) between TB #2 and NC-TB.

Next, methods for transmitting and receiving a TB to which network coding is applied through FAs in a communication system will be described.

5 is a flowchart illustrating a second embodiment of a TB transmission/reception method based on a network coding scheme in a communication system.

The "second embodiment of the method for transmitting and receiving TB based on the network coding scheme" shown in FIG. 5 may be performed by the communication nodes #1 and #2 (310, 320) shown in FIG. Therefore, "a second embodiment of a method for transmitting and receiving a TB based on a network coding scheme" will be described below with reference to FIGS. 3 and 5 .

3 and 5 , data packets to be transmitted to communication node #2 320 (P #i, P #(i+1), P #(i+2), P #(i+3), etc. ) exists in the buffer, the communication node #1 310 may generate a TB to be transmitted to each of the FAs using the data packet present in the buffer, and may generate control information for the TB.

For example, communication node #1 310 may generate TBs #0 to #(n-2) to be transmitted to FAs #0 to #(n-2), respectively, and TB #0 to #(n-) 2) TB control information for each may be generated (S501). n may be an integer of 3 or more. TB control information for each of TBs #0 to #(n-2) may include resource allocation information, MCS level, HARQ process ID, and the like. For example, the resource allocation information for TB #0 may indicate a data channel (ie, time-frequency resources in which TB #0 is transmitted) belonging to subframe #m of FA #0, and of TB #0 The HARQ process ID may be set to #0. The resource allocation information for TB #1 may indicate a data channel (ie, time-frequency resources in which TB #1 is transmitted) belonging to subframe #m of FA #1, and the HARQ process ID of TB #1 is It can be set to #1. Resource allocation information for TB #(n-2) indicates a data channel (ie, time-frequency resources through which TB #(n-2) is transmitted) belonging to subframe #m of FA #(n-2). and the HARQ process ID of TB #(n-2) may be set to #(n-2). m may be an integer greater than or equal to 0.

#1

#2"일 수 있다. NC-TB를 위한 제어 정보(이하, "NC-TB 제어 정보"라 함)는 NC 플래그(flag), FA 인덱스(index) 리스트, HARQ 프로세스 ID 리스트, 자원 할당 정보, MCS 레벨 등을 포함할 수 있다. NC 플래그는 NC-TB 제어 정보의 자원 할당 정보에 의해 지시되는 시간-주파수 자원들을 통해 NC-TB가 전송되는 것을 지시할 수 있다. FA 인덱스 리스트는 NC-TB를 구성하는 TB #0 내지 #(n-2) 각각이 전송되는 FA 인덱스(예를 들어, FA #0 내지 #(n-2))를 지시할 수 있다. 예를 들어, n이 4인 경우, FA 인덱스 리스트는 FA #0 내지 #2를 지시할 수 있다.In addition, the communication node #1 310 may generate an NC-TB to be transmitted to the FA #(n-1) and may generate control information for the NC-TB (S502). NC-TB may be generated by applying network coding (eg, XOR) to TBs #0 to #(n-2). For example, if n is 4, NC-TB is "TB #0

#One

#2". Control information for NC-TB (hereinafter referred to as "NC-TB control information") includes an NC flag, an FA index list, a HARQ process ID list, resource allocation information, may include an MCS level, etc. The NC flag may indicate that the NC-TB is transmitted through time-frequency resources indicated by the resource allocation information of the NC-TB control information. Each of TB #0 to #(n-2) constituting may indicate an FA index (eg, FA #0 to #(n-2)) being transmitted. For example, when n is 4 , FA index list may indicate FA #0 to #2.

The HARQ processor ID list may indicate HARQ process IDs (eg, HARQ processor IDs #0 to #(n-2)) of TBs #0 to #(n-2) constituting the NC-TB. For example, when n is 4, the HARQ processor ID list may indicate HARQ process IDs #0 to #2. The HARQ process ID list may not indicate the HARQ process ID for the NC-TB, and the HARQ retransmission operation for the NC-TB may not be performed. However, the communication node #2 320 may transmit a HARQ response (eg, ACK or NACK) for the NC-TB to the communication node #1 310 .

In addition, the resource allocation information for NC-TB may indicate a data channel (ie, time-frequency resources through which NC-TB is transmitted) belonging to subframe #m of FA #(n-1). The MCS level for the NC-TB may indicate the MCS level of each of TBs #0 to #(n-2) constituting the NC-TB.

Communication node #1 310 may transmit TB control information and TB #0 to #(n-2) to communication node #2 320 through FA #0 to #(n-2), and FA #( The communication node #2 320 may transmit the NC-TB control information and the NC-TB through n-1) (S503). The TB transmitted in step S503 may be a super-transmission TB. For example, communication node #1 310 may transmit TB control information and TB #0 through subframe #m of FA #0, TB control information and TB # through subframe #m of FA #1 1 may be transmitted, TB control information and TB #(n-2) may be transmitted through subframe #m of FA #(n-2), and subframe #m of FA #(n-1) may be transmitted. NC-TB control information and NC-TB may be transmitted.

Communication node #2 320 may receive TB control information in subframe #m of FA #0 to #(n-2), and based on information indicated by TB control information, TB #0 to #( n-2) can be received. In addition, the communication node #2 320 may receive the NC-TB control information in subframe #m of the FA #(n-1), and based on the information indicated by the NC-TB control information, the NC-TB can receive For example, the communication node #2 320 may determine that the NC-TB is transmitted through time-frequency resources indicated by the resource allocation information based on the NC flag included in the NC-TB control information, Based on the FA index list included in the NC-TB control information, it is possible to check the FA to which each of the TBs constituting the NC-TB is transmitted, and based on the HARQ process ID list included in the NC-TB control information, the NC-TB It is possible to check the HARQ process ID of each of the TBs constituting the TBs.

Communication node #2 320 may perform demodulation/decoding operations on TBs #0 to #(n-2) and NC-TB (S504). Communication node #2 (320) may transmit the result (eg, HARQ response) of step S504 to communication node #1 (310) (S505). When the TB (or NC-TB) is successfully received (eg, there is no error in the TB (or NC-TB)), communication node #2 320 sends the TB (or NC-TB) HARQ ACK for TB) may be transmitted to communication node #1 (#310). On the other hand, if the TB (or NC-TB) is not successfully received (eg, there is an error in the TB (or NC-TB)), communication node #2 320 sends the TB (or, HARQ NACK for NC-TB) may be transmitted to communication node #1 (#310). The communication node #1 310 may receive the HARQ response from the communication node #2 320 , and may check whether the reception of the TB and the NC-TB is successful based on the HARQ response.

Operations of communication nodes #1 and #2 (310, 320) after step S505 may vary according to the result of step S504 (eg, HARQ ACK or HARQ NACK). For example, operations of communication nodes #1 and #2 (310, 320) after step S505 may vary for each case in Table 1.

■ Case #1

Communication node #2 320 may obtain a data packet (eg, RLC PDU) from TB #0 to #(n-2), and store the data packet in a buffer of communication node #2 320 . have. In addition, the RLC layer of the communication node #2 320 may sequentially transmit the data packet to the upper layer. NC-TB may be deleted in communication node #2 (320). On the other hand, communication node #1 310 determines that TB #0 to #(n-2) have been successfully received from communication node #2 320 based on the HARQ response received from communication node #2 320 . can do. In this case, TBs #0 to #(n-2) in communication node #1 310 may be deleted. Thereafter, the communication node #1 310 may generate new supertransmission TBs, and may perform a transmission procedure for the new supertransmission TBs using TBs #0 to #(n-1).

■ Case #2

If "n = 4" and the HARQ response is as in Table 2, communication node #2 320 performs network decoding (eg, XOR) between "TB #0 and #1" and NC-TB to TB by #2 can be obtained.

#2"를 획득할 수 있고, TB #1과 "TB #1

#2" 간의 네트워크 디코딩을 수행함으로써 "TB #2"을 획득할 수 있다. 즉, 네트워크 디코딩에 의해 TB #2가 복구될 수 있다. 그 후에, 통신 노드 #2(320)는 TB #0 내지 #2로부터 데이터 패킷(예를 들어, RLC PDU)을 획득할 수 있고, 데이터 패킷을 버퍼에 저장할 수 있다. 또한, 통신 노드 #2(320)의 RLC 계층은 데이터 패킷을 순차적으로 상위 계층에 전송할 수 있다.For example, communication node #2 (320) performs network decoding between TB #0 and NC-TB to "TB #1

#2" can be obtained, TB #1 and "TB #1

"TB #2" can be obtained by performing network decoding between "#2". That is, TB #2 can be recovered by network decoding. After that, the communication node #2 (320) transmits TB #0 to A data packet (eg, RLC PDU) may be obtained from #2, and the data packet may be stored in a buffer, and the RLC layer of the communication node #2 320 sequentially transmits the data packet to an upper layer. can

On the other hand, the communication node #1 310 confirms that the HARQ response of one of TBs #0 to #2 (ie, TB #2) is NACK based on the HARQ response received from the communication node #2 320 . can Also, the communication node #1 310 may confirm that the HARQ responses of TB #0, TB #1, and NC-TB are ACKs based on the HARQ response received from the communication node #2 320 . In this case, the communication node #1 310 may determine that the recovery of TB #2 is possible based on “TB #0, TB #1 and NC-TB” in the communication node #2 320 , and accordingly Retransmission of TB #2 may not be performed. In communication node #1 310 , TBs #0 to #2 may be deleted. Thereafter, the communication node #1 310 may generate new supertransmission TBs, and may perform a transmission procedure for the new supertransmission TBs using TBs #0 to #3.

■ Case #3

6 is a flowchart illustrating a third embodiment of a TB transmission/reception method based on a network coding scheme in a communication system.

The "third embodiment of the method for transmitting and receiving TB based on the network coding scheme" shown in FIG. 6 may be performed after the "second embodiment of the method for transmitting and receiving TB based on the network coding scheme" shown in FIG. 5 .

Referring to FIG. 6 , if "n = 4", and the HARQ response is as in Table 3 or Table 4, communication node #2 320 transmits a successfully received TB (eg, TB # in the case of Table 3). In the case of 0 and #1 and Table 4, TB #0) may be stored in the buffer (S601). Here, data packets belonging to the successfully received TB may be stored in the buffer.

When the HARQ response is received from communication node #2 320, communication node #1 310 is a TB that was not successfully received at communication node #2 320 based on the HARQ response (eg, in Table 3). In the case of TB #2, in the case of Table 4, TB #1 and #2) can be identified. Also, in case #3, the communication node #1 310 may determine that recovery of the TB based on the NC-TB is impossible. Accordingly, the communication node #1 310 may perform a retransmission procedure of the TB (eg, TB #2 in the case of Table 3 and TB #1 and #2 in the case of Table 4).

For example, for example, the number of FAs used for communication between communication node #1 310 and communication node #2 320 is n, and the number of TBs not successfully received in communication node #2 320 is If the number is s, the retransmission procedure of s TBs using n FAs, the supertransmission procedure of (n-1-s) new TBs, and NC-TBs (eg, s TBs and (n-1 A transmission procedure of NC-TB) generated by network coding among -s) new TBs may be performed.

In the case of Table 3, communication node #1 310 has TB #4 and TB control information to be transmitted to FA #0, TB #5 and TB control information to be transmitted to FA #1, and TB # to be transmitted to FA #2. 2 and TB control information may be generated (S602). Here, TBs #4 and #5 may be supertransmission TBs, and TB #2 may be retransmission TBs. TB control information for each of TBs #2, #4, and #5 may include resource allocation information, MCS level, HARQ process ID, and the like.

#4

#5"일 수 있다. NC-TB 제어 정보는 NC 플래그, FA 인덱스 리스트, HARQ 프로세스 ID 리스트, 자원 할당 정보, MCS 레벨 등을 포함할 수 있다. FA 인덱스 리스트는 FA #0 내지 #2를 지시할 수 있다. HARQ 프로세서 ID 리스트는 TB #2, #4 및 #5 각각의 HARQ 프로세스 ID #2, #4 및 #5를 지시할 수 있다.In addition, the communication node #1 310 may generate an NC-TB to be transmitted to the FA #3 and may generate NC-TB control information (S603). NC-TB may be generated by applying network coding (eg, XOR) to TBs #2, #4, and #5. That is, NC-TB is "TB #2

#4

It may be #5". The NC-TB control information may include an NC flag, an FA index list, a HARQ process ID list, resource allocation information, MCS level, etc. The FA index list indicates FAs #0 to #2. The HARQ processor ID list may indicate HARQ process IDs #2, #4, and #5 of TB #2, #4, and #5, respectively.

Communication node #1 310 may transmit TB (ie, TB #2, #4 and #5) and TB control information to communication node #2 320 through FA #0 to #2, and FA #3 It is possible to transmit the NC-TB and NC-TB control information to the communication node #2 (320) through (S604).

Communication node #2 320 may receive TB control information from FAs #0 to #2, and may receive TBs #2, #4, and #5 based on information indicated by the TB control information. In addition, the communication node #2 320 may receive the NC-TB control information from the FA #3, and may receive the NC-TB based on information indicated by the NC-TB control information. For example, the communication node #2 320 may determine that the NC-TB is transmitted through time-frequency resources indicated by the resource allocation information based on the NC flag included in the NC-TB control information, Based on the FA index list included in the NC-TB control information, it is possible to check the FA to which each of the TBs constituting the NC-TB is transmitted, and based on the HARQ process ID list included in the NC-TB control information, the NC-TB It is possible to check the HARQ process ID of each of the TBs constituting the TBs.

Communication node #2 320 may perform demodulation/decoding operations on TB #2, TB #4, TB #5, and NC-TB (S605). Communication node #2 (320) may transmit the result (eg, HARQ response) of step S605 to communication node #1 (310) (S606). When the result of step S605 is Case #1 or #2, demodulation/decoding operations for TB #2, TB #4, and TB #5 are performed on the basis of the procedure (eg, network decoding) described above for communication node # It may be completed successfully at 2 ( 320 ). TB #2, TB #4, and TB #5 may be stored in a buffer of communication node #2 (320). The RLC layer of the communication node #2 320 may sequentially transmit data packets (eg, RLC PDUs) of TB #0 to #5 stored in the buffer to a higher layer.

If the result of step S605 is case #3 or #4, and the HARQ response of TB #2 is ACK, the communication node #2 320 may store the decoded TB #2 in a buffer, and the TB whose HARQ response is NACK A retransmission procedure may be performed for . Alternatively, when the result of step S605 is case #3 or #4, and the HARQ response of TB #2 is NACK, the retransmission procedure for TB #2 may be performed again.

In the case of Table 4, communication node #1 310 has TB #4 and TB control information to be transmitted to FA #0, TB #1 and TB control information to be transmitted to FA #1, and TB # to be transmitted to FA #2. 2 and TB control information may be generated (S602). Here, TB #4 may be a supertransmission TB, and TBs #1 and #2 may be retransmission TBs. TB control information for each of TBs #1, #2, and #4 may include resource allocation information, MCS level, HARQ process ID, and the like.

#2

#4"일 수 있다. NC-TB 제어 정보는 NC 플래그, FA 인덱스 리스트, HARQ 프로세스 ID 리스트, 자원 할당 정보, MCS 레벨 등을 포함할 수 있다. FA 인덱스 리스트는 FA #0 내지 #2를 지시할 수 있다. HARQ 프로세서 ID 리스트는 TB #1, #2 및 #4 각각의 HARQ 프로세스 ID #1, #2 및 #4를 지시할 수 있다.In addition, the communication node #1 310 may generate an NC-TB to be transmitted to the FA #3 and may generate NC-TB control information (S603). NC-TB may be generated by applying network coding (eg, XOR) to TBs #1, #2 and #4. That is, NC-TB is "TB #1

#2

It may be #4". The NC-TB control information may include an NC flag, FA index list, HARQ process ID list, resource allocation information, MCS level, etc. The FA index list indicates FA #0 to #2. The HARQ processor ID list may indicate HARQ process IDs #1, #2 and #4 of TB #1, #2 and #4, respectively.

Communication node #1 (310) may transmit TB (ie, TB #1, #2 and #4) and TB control information to communication node #2 (320) through FAs #0 to #2, and FA #3 It is possible to transmit the NC-TB and NC-TB control information to the communication node #2 (320) through (S604).

Communication node #2 320 may receive TB control information from FAs #0 to #2, and may receive TBs #1, #2, and #4 based on information indicated by the TB control information. In addition, the communication node #2 320 may receive the NC-TB control information from the FA #3, and may receive the NC-TB based on information indicated by the NC-TB control information. For example, the communication node #2 320 may determine that the NC-TB is transmitted through time-frequency resources indicated by the resource allocation information based on the NC flag included in the NC-TB control information, Based on the FA index list included in the NC-TB control information, it is possible to check the FA to which each of the TBs constituting the NC-TB is transmitted, and based on the HARQ process ID list included in the NC-TB control information, the NC-TB It is possible to check the HARQ process ID of each of the TBs constituting the TBs.

Communication node #2 320 may perform demodulation/decoding operations on TB #1, TB #2, TB #4, and NC-TB (S605). Communication node #2 (320) may transmit the result (eg, HARQ response) of step S605 to communication node #1 (310) (S606). When the result of step S605 is Case #1 or #2, demodulation/decoding operations for TB #1, TB #2, and TB #4 are performed on the basis of the above-described procedure (eg, network decoding) communication node # It may be completed successfully at 2 ( 320 ). TB #1, TB #2, and TB #4 may be stored in a buffer of communication node #2 (320). The RLC layer of the communication node #2 320 may sequentially transmit data packets (eg, RLC PDUs) of TB #0 to #4 stored in the buffer to a higher layer.

If the result of step S605 is case #3 or #4, and the HARQ response of TB #1 and #2 is ACK, communication node #2 320 may store the decoded TB #1 and #2 in a buffer, A retransmission procedure for a TB whose HARQ response is NACK may be performed. Alternatively, when the result of step S605 is case #3 or #4, and the HARQ responses of TBs #1 and #2 are NACK, the retransmission procedure for TBs #1 and #2 may be performed again.

■ Case #4

7 is a flowchart illustrating a fourth embodiment of a TB transmission/reception method based on a network coding scheme in a communication system.

The "fourth embodiment of the method for transmitting and receiving TB based on the network coding scheme" shown in FIG. 7 may be performed after the "second embodiment of the method for transmitting and receiving TB based on the network coding scheme" shown in FIG. 5 .

#2(이하, NC-TB'라 함)를 생성할 수 있다(S701). 통신 노드 #2(320)는 TB #0 및 NC-TB'을 버퍼에 저장할 수 있다(S702). 또한, NC-TB'를 구성하는 TB #1 및 #2 각각의 HARQ 프로세스 ID도 버퍼에 저장될 수 있다.Referring to FIG. 7 , when “n = 4” and the HARQ response is as shown in Table 5, communication node #2 320 performs network decoding between TB #0 and NC-TB to TB #1

#2 (hereinafter, referred to as NC-TB') may be generated (S701). Communication node #2 320 may store TB #0 and NC-TB' in a buffer (S702). In addition, HARQ process IDs of TBs #1 and #2 constituting NC-TB' may also be stored in the buffer.

When the HARQ response is received from the communication node #2 320, the communication node #1 310 determines that TB #1 and #2 were not successfully received at the communication node #2 320 based on the HARQ response. can do. Communication node #1 310 may determine that in case #4, recovery of TBs #1 and #2 based on NC-TB is impossible. Accordingly, the communication node #1 310 may perform a retransmission procedure of TB #1 or #2. When one of TB #1 or #2 is successfully received from communication node #2 320, TB #2 (or TB #2 (or TB #2) based on the received TB #1 (or TB #2) and NC-TB' , TB #1) can be recovered, so communication node #1 310 can retransmit either TB #1 or TB #2. That is, when it is determined that s TBs are unrecoverable in communication node #2 320 (eg, when s TBs are not successfully received in communication node #2 320), communication node #1 ( 310) is a retransmission procedure of (s-1) TBs among s TBs using n FAs, a supertransmission procedure of (n-1-(s-1)) TBs, and NC-TB (for example , a transmission procedure of (s-1) TBs and (n-1-(s-1)) TBs generated by network coding (NC-TB). Here, s may be an integer of 2 or more.

If it is determined to retransmit TB #1, communication node #1 310 transmits TB #4 and TB control information to be transmitted to FA #0, TB #1 and TB control information to be transmitted to FA #1, and FA #2. It is possible to generate TB #5 and TB control information to be transmitted to (S703). Here, TBs #4 and #5 may be supertransmission TBs, and TB#1 may be retransmission TBs. TB control information for each of TBs #1, #4, and #5 may include resource allocation information, MCS level, HARQ process ID, and the like.

#4

#5"일 수 있다. NC-TB 제어 정보는 NC 플래그, FA 인덱스 리스트, HARQ 프로세스 ID 리스트, 자원 할당 정보, MCS 레벨 등을 포함할 수 있다. FA 인덱스 리스트는 FA #0 내지 #2를 지시할 수 있다. HARQ 프로세서 ID 리스트는 TB #1, #4 및 #5 각각의 HARQ 프로세스 ID #1, #4 및 #5를 지시할 수 있다. 통신 노드 #1(310)은 FA #0 내지 #2를 통해 TB(즉, TB #1, #4 및 #5) 및 TB 제어 정보를 통신 노드 #2(320)에 전송할 수 있고, FA #3을 통해 NC-TB 및 NC-TB 제어 정보를 통신 노드 #2(320) 전송할 수 있다(S705).In addition, the communication node #1 310 may generate an NC-TB to be transmitted to the FA #3 and may generate NC-TB control information (S704). NC-TB may be generated by applying network coding (eg, XOR) to TBs #1, #4 and #5. That is, NC-TB is "TB #1

#4

It may be #5". The NC-TB control information may include an NC flag, an FA index list, a HARQ process ID list, resource allocation information, MCS level, etc. The FA index list indicates FAs #0 to #2. The HARQ processor ID list may indicate HARQ process IDs #1, #4, and #5, respectively, of TB #1, #4, and #5. Communication node #1 310 is FA #0 to # TB (ie, TB #1, #4, and #5) and TB control information may be transmitted to communication node #2 (320) via 2, and NC-TB and NC-TB control information may be communicated via FA #3 Node #2 (320) can transmit (S705).

Communication node #2 320 may receive TB control information from FAs #0 to #2, and may receive TBs #1, #4, and #5 based on information indicated by the TB control information. In addition, the communication node #2 320 may receive the NC-TB control information from the FA #3, and may receive the NC-TB based on information indicated by the NC-TB control information. For example, the communication node #2 320 may determine that the NC-TB is transmitted through time-frequency resources indicated by the resource allocation information based on the NC flag included in the NC-TB control information, Based on the FA index list included in the NC-TB control information, it is possible to check the FA to which each of the TBs constituting the NC-TB is transmitted, and based on the HARQ process ID list included in the NC-TB control information, the NC-TB It is possible to check the HARQ process ID of each of the TBs constituting the TBs.

Communication node #2 320 may perform demodulation/decoding operations on TB #1, TB #4, TB #5, and NC-TB (S706). Communication node #2 (320) may transmit the result (eg, HARQ response) of step S706 to communication node #1 (310) (S707). When the result of step S706 is Case #1 or #2, demodulation/decoding operations for TB #1, TB #4, and TB #5 may be successfully completed in communication node #2 (320).

Since TB #1 is a retransmission TB, communication node #2 320 may obtain NC-TB' including TB #1 from the buffer using the FA index and HARQ process ID of TB #1 (S708). For example, the communication node #2 320 may obtain NC-TB' having the same HARQ process ID as the HARQ process ID of TB #1 from the buffer. In this case, the HARQ process ID list included in the control information of NC-TB' may include the HARQ processor ID of TB #1.

#2이기 때문에, 통신 노드 #2(320)는 TB #1과 NC-TB' 간의 네트워크 디코딩을 수행함으로써 TB #2를 획득할 수 있다(S709). TB #2는 통신 노드 #2(320)의 버퍼에 저장될 수 있고, 단계 S705에서 수신된 TB #4 및 #5도 통신 노드 #2(320)의 버퍼에 저장될 수 있다. 통신 노드 #2(320)의 RLC 계층은 버퍼에 저장된 TB #0 내지 #5의 데이터 패킷(예를 들어, RLC PDU)을 순차적으로 상위 계층에 전송할 수 있다.NC-TB' obtained in step S708 is TB #1

Since it is #2, the communication node #2 320 may obtain TB #2 by performing network decoding between TB #1 and NC-TB' (S709). TB #2 may be stored in the buffer of communication node #2 320 , and TBs #4 and #5 received in step S705 may also be stored in the buffer of communication node #2 320 . The RLC layer of the communication node #2 320 may sequentially transmit data packets (eg, RLC PDUs) of TB #0 to #5 stored in the buffer to a higher layer.

Alternatively, when the result of step S706 is case #3 or #4, and the HARQ response of TB #1 is ACK, communication node #2 320 may obtain TB #2 by performing steps S708 and S709. . Alternatively, when the result of step S706 is case #3 or #4, and the HARQ response of TB #1 is NACK, the retransmission procedure for TB #1 may be performed again.

Meanwhile, in the embodiments described with reference to FIGS. 5 to 7 , the operation of the communication node #1 310 (ie, the transmission communication node) may be summarized as follows.

8 is a flowchart illustrating a first embodiment of a method for transmitting a TB based on a network coding scheme in a communication system.

Referring to FIG. 8 , the communication node #1 310 may generate TB and TB control information to be transmitted to FAs #0 to #(n-2) (S801). The TB generated in step S801 may be a supertransmission TB. Step S801 may be performed the same as or similar to step S501 shown in FIG. 5 . Communication node #1 310 may generate NC-TB and NC-TB control information to be transmitted to FA #(n-1) (S802). The NC-TB may be generated by performing network coding on TBs to be transmitted to FAs #0 to #(n-2). Step S802 may be performed the same as or similar to step S502 shown in FIG. 5 .

Communication node #1 310 may transmit TB, TB control information, NC-TB, and NC-TB control information through FAs #0 to #(n-1) (S803). Step S803 may be performed the same as or similar to step S503 shown in FIG. 5 . Communication node #1 310 may receive the HARQ response for the TB and NC-TB transmitted in step S803 (S804). When the HARQ responses for all TBs transmitted in step S803 are ACK (that is, case #1 in Table 1), communication node #1 310 starts from step S801 for the initial transmission procedure of a new TB. actions can be performed.

On the other hand, if there is one or more NACKs among the HARQ responses for all TBs transmitted in step S803, the communication node #1 310 checks whether the HARQ response for the NC-TB transmitted in step S803 is ACK. can When the HARQ response for the NC-TB transmitted in step S803 is NACK (eg, case #3 in Table 1), the communication node #1 310 may perform steps S805 and S806. For example, when the number of TBs not successfully received in communication node #2 320 is s (eg, when there are s NACKs among HARQ responses for TBs), communication node #1 310 may generate (n-1-s) supertransmission TBs, s retransmission TBs, and TB control information (S805). In addition, communication node #1 310 may generate an NC-TB by performing network coding between (n-1-s) supertransmission TBs and s retransmission TBs, and may generate NC-TB control information. There is (S806). Step S805 may be performed the same or similar to step S602 illustrated in FIG. 6 , and step S806 may be performed identically or similarly to step S603 illustrated in FIG. 6 . When step S806 is completed, the communication node #1 310 may perform operations starting from step S803.

On the other hand, when the HARQ response for the NC-TB transmitted in step S803 is ACK, the communication node #1 (310) is the number of TBs that have not been successfully received in the communication node #2 (320) (s) (for example, , the number of NACKs among HARQ responses for TBs). When s is not greater than 1 (eg, case #2 of Table 1), the communication node #1 310 may perform operations starting from step S801. On the other hand, when s is greater than 1 (eg, case #4 in Table 1), the communication node #1 310 may perform steps S807 and S808. For example, the communication node #1 310 may generate (n-1-(s-1)) supertransmission TBs, (s-1) retransmission TBs, and TB control information (S807). In addition, communication node #1 310 may generate an NC-TB by performing network coding between (n-1-(s-1)) supertransmission TBs and (s-1) retransmission TBs, and NC -TB control information can be generated (S808). Step S807 may be performed the same as or similar to step S703 illustrated in FIG. 7 , and step S808 may be performed identically or similarly to step S704 illustrated in FIG. 7 . When step S808 is completed, the communication node #1 310 may perform operations starting from step S803.

Meanwhile, in the embodiments described with reference to FIGS. 5 to 7 , the operation of the communication node #2 320 (ie, the receiving communication node) may be organized as follows.

9A is a flowchart illustrating a first embodiment of a method for receiving a TB based on a network coding scheme in a communication system, and FIG. 9B is a flowchart illustrating a second embodiment of a method for receiving a TB based on a network coding scheme in a communication system. to be.

9A and 9B , communication node #2 320 may receive TB, NC-TB, and control information from FA #0 to #(n-1) from communication node #1 310 ( S901). Step S901 may be performed the same or similar to step S503 shown in FIG. 5, step S604 shown in FIG. 6, or step S705 shown in FIG. The communication node #2 320 may perform demodulation/decoding operations on the received TB and NC-TB, and may transmit an HARQ response resulting from the decoding operation to the communication node #1 310 ( S902 ). The HARQ response may be transmitted for each FA. When the HARQ response for all TBs received in step S901 is ACK, communication node #2 320 may detect a data packet (eg, RLC PDU) from the TBs, and buffer the detected data packet. It can be stored in (S903).

When all the TBs received in step S901 are super-transmission TBs, the RLC layer of the communication node #2 320 may sequentially transmit the data packets stored in the buffer to the upper layer (S904). When step S904 is completed, the communication node #2 320 may perform operations starting from step S901. When all the TBs received in step S901 are not supertransmission TBs (eg, when at least one TB among the TBs received in step S901 is a retransmission TB), communication node #2 320 corresponds to the retransmission TB NC-TB' can be detected from the buffer (S905). In addition, the communication node #2 320 may perform network decoding between the retransmission TB and the NC-TB' (S906). Step S905 may be performed the same as or similar to step S708 illustrated in FIG. 7 , and step S906 may be performed identically or similarly to step S709 illustrated in FIG. 7 .

As a result of performing step S906, NC-TB" may be generated, and when the number of TBs included in NC-TB" is not greater than 1 (for example, when NC-TB" consists of one TB), Communication node #2 320 may detect a data packet (eg, RLC PDU) from the TB obtained in step S906, and may store the detected data packet in a buffer (S907). The RLC layer of 2 320 may sequentially transmit the data packets stored in the buffer to the upper layer (S908). When step S908 is completed, the communication node #2 320 may perform the operations starting from step S901. On the other hand, when the number of TBs included in "NC-TB" is greater than 1 (for example, when NC-TB" consists of two or more TBs), communication node #2 320 in step S906 The acquired NC-TB" may be stored in the buffer (S909). When the data packet exists in the buffer after step S909 is completed, the RLC layer of the communication node #2 320 may sequentially transmit the data packet stored in the buffer to the upper layer (S908). When step S908 is completed, the communication node #2 320 may perform operations starting from step S901.

On the other hand, when the HARQ responses for all TBs received in step S901 are not ACKs (eg, if there is one or more NACKs among the HARQ responses for the TBs received in step S901), communication node #2 320 may check whether the HARQ response for the NC-TB received in step S901 is ACK. When the HARQ response to the NC-TB is ACK, the communication node #2 320 may detect a data packet (eg, RLC PDU) from the ACK TB received in step S901, and buffer the detected data packet. It can be stored in (S910). Here, the ACK TB may refer to a TB successfully received in the communication node #2 (320). If the number (s) of NACK TBs among the TBs received in step S901 is not greater than 1 (eg, when the number (s) of NACK TBs is 1), communication node #2 320 performs steps S911 and Step S912 may be performed. Here, the NACK TB may refer to a TB that has not been successfully received in the communication node #2 320 .

For example, the communication node #2 320 may recover the NACK TB by performing network decoding between (n-1-s) ACK TBs and NC-TBs (S911). For example, a TB in which no error exists may be obtained when step S911 is completed. Communication node #2 320 may detect a data packet (eg, an RLC PDU) from the TB recovered in step S911, and may store the detected data packet in a buffer (S912). After completion of step S912, the communication node #2 320 may check whether a retransmission TB exists among the TBs obtained in step S901. If there is a retransmission TB among the TBs obtained in step S901, the communication node #2 320 may perform operations starting from step S905. If there is no retransmission TB among the TBs obtained in step S901, the RLC layer of the communication node #2 320 may sequentially transmit the data packets stored in the buffer to the upper layer (S913). When step S913 is completed, the communication node #2 320 may perform operations starting from step S901.

Meanwhile, when the number (s) of NACK TBs among the TBs received in step S901 is greater than 1, the communication node #2 320 may perform steps S914 and S915. For example, communication node #2 320 may perform network decoding between (n-1-s) ACK TBs and NC-TBs (S914). Communication node #2 320 may store the result of step S914 (eg, NC-TB'), NACK TB information (eg, FA index of NACK TB and HARQ process ID), etc. in a buffer. (S915). After step S915 is completed, the communication node #2 320 may perform the operations starting from step S905 or operations starting from step S913 depending on whether a retransmission TB exists in the TBs received in step S901.

On the other hand, if there is a NACK TB among the TBs received in step S901, and the HARQ response to the NC-TB received in step S901 is NACK, the communication node #2 320 sends a data packet (for example, from the ACK TB). , RLC PDU) may be detected, and the detected data packet may be stored in a buffer (S916). After step S916 is completed, the communication node #2 320 may perform the operations starting from step S905 or operations starting from step S913 depending on whether a retransmission TB exists in the TBs received in step S901.

Meanwhile, the reception success probability according to the embodiments of the present invention and the reception success probability in the existing communication system may be as shown in Table 6 below. The reception success probability according to the embodiments of the present invention may be "(P _e ) ⁿ + n((P _e ) ⁿ - (P _e ) ⁿ⁺¹ )", and the reception success probability in the existing communication system is (P _e ) can be ⁿ .

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, and the like, 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 signal transmission method performed by a communication node #1 in a communication system, comprising:
Generate TB control information for TB (transport block) #0 to #(n-2) and TB #0 to #(n-2) transmitted in frequency alignment (FA) #0 to #(n-2) to do;
generating a network coding (NC)-TB transmitted to FA #(n-1) and NC-TB control information for the NC-TB;
transmitting the TB control information and the TBs #0 to #(n-2) through the FAs #0 to #(n-2); and
Transmitting the NC-TB control information and the NC-TB through the FA #(n-1),
The NC-TB is generated by performing network coding on the TBs #0 to #(n-2), wherein n is an integer of 3 or more. The method according to claim 1,
The signal transmission method comprises:
receiving a hybrid automatic repeat request (HARQ) response for the TBs #0 to #(n-2) and the NC-TB from the communication node #2; and
When the HARQ response to the NC-TB is ACK (acknowledgement), and the HARQ response to one TB among the TBs #0 to #(n-2) is NACK (negative ACK), the one TB The method further comprising: performing a supertransmission procedure for (n-1) new TBs using the FAs #0 to #(n-1) without performing a retransmission procedure for . The method according to claim 1,
The signal transmission method comprises:
receiving HARQ responses for the TBs #0 to #(n-2) and the NC-TB from communication node #2; and
When the HARQ response to the NC-TB is NACK, the HARQ response to s TBs among the TBs #0 to #(n-2) is NACK, and the s is 1 or more, the FAs #0 to # and performing a retransmission procedure for the s TBs using (n-1) and a supertransmission procedure for (n-1-s) new TBs. The method according to claim 1,
The signal transmission method comprises:
receiving HARQ responses for the TBs #0 to #(n-2) and the NC-TB from communication node #2; and
If the HARQ response to the NC-TB is ACK, the HARQ response to s TBs among the TBs #0 to #(n-2) is NACK, and s is an integer of 2 or more, the FA #0 to performing a retransmission procedure for (s-1) TBs and a supertransmission procedure for (n-1-(s-1)) new TBs among the s TBs using #(n-1) Further comprising, a signal transmission method. The method according to claim 1,
The NC-TB control information includes an NC flag indicating that the NC-TB is transmitted, and an index of an FA in which the TBs #0 to #(n-2) constituting the NC-TB are transmitted. ) indicating the FA index list (list) and the HARQ process ID list indicating the HARQ process ID (identifier) of each of the TBs #0 to #(n-2) constituting the NC-TB , signal transmission method. The method according to claim 1,
Each of the FAs #0 to #(n-1) is set to a different frequency band, and the FAs #0 to #(n-1) belong to the entire frequency band of the communication system. The method according to claim 1,
The TB control information, the TBs #0 to #(n-2), the NC-TB control information, and the NC-TB are transmitted through the same subframe. The method according to claim 1,
wherein the network coding is an exclusive OR (XOR) operation. A signal receiving method performed by a communication node #1 in a communication system, comprising:
TB control information for TB (transport block) #0 to #(n-2) in frequency alignment (FA) #0 to #(n-2) and the TB #0 to #(n-2) to the communication node # receiving from 2;
receiving NC-TB control information for network coding (NC)-TB and the NC-TB from the communication node #2 in FA#(n-1); and
Transmitting a hybrid automatic repeat request (HARQ) response for the TBs #0 to #(n-1) and the NC-TB to the communication node #2 through the FAs #0 to #(n-1) includes,
The NC-TB is generated by performing network coding on the TBs #0 to #(n-2), wherein n is an integer of 3 or more. 10. The method of claim 9,
The method of receiving the signal,
When the HARQ response to the NC-TB is acknowledgment (ACK), and the HARQ response to one TB among the TBs #0 to #(n-2) is NACK (negative ACK),
The method further comprises the step of recovering the one TB by performing network decoding between the NC-TB and the remaining TBs except for the one TB among the TBs #0 to #(n-2), wherein the network decoding is an XOR (exclusive OR) operation, a signal reception method. 10. The method of claim 9,
The method of receiving the signal,
The method further includes performing network decoding between the retransmission TB and the NC-TB' stored in the buffer of the communication node #1 when there is a retransmission TB among the TBs #0 to #(n-2), wherein the NC -TB' is received from the communication node #2 before the reception of the NC-TB. 10. The method of claim 9,
The method of receiving the signal,
When the HARQ response to the NC-TB is ACK, the HARQ response to s TBs among the TBs #0 to #(n-2) is NACK, and the s is an integer of 2 or more, the TB #0 to performing network decoding between the NC-TBs and the remaining TBs except for the s TBs among #(n-2); and
and storing the result of the network decoding in a buffer of the communication node #1. 13. The method of claim 12,
In the step of storing in the buffer of the communication node #1,
The HARQ process ID (identifier) of the s TBs together with the result of the network decoding is stored in the buffer of the communication node #1. 13. The method of claim 12,
The method of receiving the signal,
re-receiving (s-1) TBs from the communication node #2 among the s TBs in the FAs #0 to #(n-1); and
The method further comprises the step of recovering the remaining TBs except for the (s-1) TBs among the s TBs by performing network decoding between the (s-1) TBs and the network decoding results stored in the buffer. Signal, How to receive. 10. The method of claim 9,
The NC-TB control information includes an NC flag indicating that the NC-TB is transmitted, and an index of an FA in which the TBs #0 to #(n-2) constituting the NC-TB are transmitted. ) ) and a HARQ process ID list indicating the HARQ process ID of each of the TBs #0 to #(n-2) constituting the NC-TB. As communication node #1 constituting a communication system,
processor; and
At least one instruction executed by the processor comprises a memory (memory) stored,
The at least one command is
TB control information for TB (transport block) #0 to #(n-2) in frequency alignment (FA) #0 to #(n-2) and the TB #0 to #(n-2) to the communication node # receive from 2;
receive NC-TB control information for network coding (NC)-TB and the NC-TB from the communication node #2 in FA #(n-1); and
is executed to transmit a hybrid automatic repeat request (HARQ) response for the TBs #0 to #(n-1) and the NC-TB to the communication node #2 through the FAs #0 to #(n-1) and ,
The NC-TB is generated by performing network coding on the TBs #0 to #(n-2), wherein n is an integer greater than or equal to 3, communication node #1. 17. The method of claim 16,
The at least one command is
When the HARQ response to the NC-TB is acknowledgment (ACK), and the HARQ response to one TB among the TBs #0 to #(n-2) is NACK (negative ACK),
and recovering the one TB by performing network decoding between the NC-TB and the remaining TBs except for the one TB among the TBs #0 to #(n-2), wherein the network decoding is XOR (exclusive OR) operation, communication node #1. 17. The method of claim 16,
The at least one command is
If there is a retransmission TB among the TBs #0 to #(n-2), the NC-TB is further executed to perform network decoding between the retransmission TB and the NC-TB' stored in the buffer of the communication node #1; ' is received from the communication node #2 before the reception of the NC-TB, communication node #1. 17. The method of claim 16,
The at least one command is
When the HARQ response to the NC-TB is ACK, the HARQ response to s TBs among the TBs #0 to #(n-2) is NACK, and the s is an integer of 2 or more, the TB #0 to performing network decoding between the NC-TBs and the remaining TBs except for the s TBs among TB #(n-2); and
and store a result of the network decoding in a buffer of the communication node #1. 20. The method of claim 19,
The at least one command is
re-receiving (s-1) TBs from the communication node #2 among the s TBs in the FAs #0 to #(n-1); and
Communication node #, further executed to recover the remaining TBs except for the (s-1) TBs among the s TBs by performing network decoding between the (s-1) TBs and the network decoding results stored in the buffer. One.

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