WO2012020917A1

WO2012020917A1 - Method and device for transmitting/receiving data in wireless communication system supporting relay node

Info

Publication number: WO2012020917A1
Application number: PCT/KR2011/004798
Authority: WO
Inventors: 김동인; 최완; 유종열; 김병훈; 서한별
Original assignee: 엘지전자 주식회사; 성균관대학교산학협력단; 한국과학기술원
Priority date: 2010-08-10
Filing date: 2011-06-30
Publication date: 2012-02-16
Also published as: KR20140012610A; KR101706960B1

Abstract

The present invention relates to a method and a device for transmitting/receiving data in a wireless communication system supporting a relay node in a wireless communication system. The method for transmitting data from a base station according to one embodiment of the present invention comprises: a step for generating a first code word by bit concatenating and encoding a first data regarding a user equipment to data regarding relay node; a step for generating a second code word by encoding a second data regarding the user equipment; and a step for transmitting the first code word to the relay node and the second code word to the user equipment.

Description

【Specification】

[Name of invention]

Method and apparatus for transmitting / receiving data in repeater supporting wireless communication system

Technical Field

The following description relates to a wireless communication system, and more particularly, to a method and apparatus for transmitting and receiving data in a wireless communication system supporting a repeater. Background Art

FIG. 1 illustrates a relay node (RN) 120 and a user equipment (UE) 131 and 132 existing in an area of one base station (eNodeB; eNB) 110 in a wireless communication system 100. The repeater 120 may transfer data received from the base station 110 to the terminal 132 in the repeater area, and may transmit data received from the terminal 132 in the repeater area to the base station 110. In addition, the repeater 120 may support extending the high data rate range, improving the communication quality at the cell edge, and providing communication within an area of the building or beyond the base station service area. In FIG. 1, a terminal (hereinafter referred to as a macro-UE or M—UE) that receives a service directly from a base station, such as a terminal 131, and a service through a relay 120 such as a terminal 132. It shows that there is a receiving terminal (hereinafter referred to as a relay-UE or an R-UE).

The wireless link between the base station 110 and the repeater 120 is called a backhaul link. The link from the base station 110 to the repeater 120 is called a backhaul downlink, and the link from the repeater 120 to the base station 110 is called a backhaul uplink. Also, the radio link between the repeater 120 and the terminal 132 is called an access link. The link from the repeater 120 to the terminal 132 is called an access downlink, and the link from the terminal 132 to the repeater 120 is called an access uplink.

When the repeater 120 operates in a manner of controlling a cell by itself, the terminal 132 may recognize the repeater 120 as a general base station. On the other hand, when another terminal (UE) functions as a repeater 120 (these repeaters are called user-relays), the terminal 132 does not recognize the existence of the repeater 120.

[Detailed Description of the Invention]

[Technical problem] In the present invention, when data is transmitted through a user-relay in transmitting data from a base station to a terminal, it is a technical problem to provide a method for more efficiently utilizing radio resources and making data transmission successful. do. Specifically, the present invention is to provide a method for configuring the data to be transmitted through the user-relay and the base station to transmit data directly to the terminal in the base station transmits the data to the terminal. Another object of the present invention is to provide a method for determining a resource, a transmission rate, etc. to be used for delivering data to a user equipment, and a method for performing retransmission due to data decoding failure at the user equipment.

Technical problems to be achieved in the present invention are not limited to the above-mentioned technical problems, and other technical problems not mentioned above will be clearly understood by those skilled in the art from the following description. Could be.

Technical Solution

In order to solve the above technical problem, a method for transmitting data in a base station according to an embodiment of the present invention, the first codeword by bit concatenation (concatenation) the first data for the terminal to the data for the repeater Generating a; Generating a second codeword by encoding second data for the terminal; And transmitting the first codeword to the repeater and transmitting the second codeword to the terminal.

In order to solve the above technical problem, a method for transmitting data in a repeater according to another embodiment of the present invention, generated by encoding the first data for the terminal bit concatenation (concatenation) in the base station to the data for the repeater together Receiving a first codeword from the base station; Extracting the first data from the first codeword; And transmitting the extracted first data to the terminal.

In order to solve the above technical problem, a base station for transmitting data according to another embodiment of the present invention, a transmission module for transmitting a signal to one or more of the repeater and the terminal; Receiving modules receiving a signal from at least one of the repeater and the terminal; And the operation of the base station connected to the reception modules and the transmission modules. It may include a processor for controlling. Wherein the processor is further configured to bit concatenate first data for the terminal to data for the repeater to encode the first data to generate a first codeword; Generate a second codeword by encoding second data for the terminal; The transmission code may be configured to transmit the first codeword to the repeater and the second codeword to the terminal.

In order to solve the above technical problem, a repeater for transmitting data according to another embodiment of the present invention, the first receiving module for receiving a signal from the base station; First transmission modules for transmitting a signal to the base station; Second receiving modules receiving a signal from a terminal; Second transmission modules for transmitting a signal to the terminal; And a processor connected to the first and second reception modules and the first and second transmission modules and controlling the operation of the repeater. Here, the processor, the first codeword generated by bit-concatenation (concatenation) at the base station with the first data for the terminal to the data for the repeater to receive from the base station through the first receiving mode and ; Extract the first data from the first codeword; The extracted first data may be configured to be transmitted to the terminal through the second transmission mode.

In the embodiments according to the present invention, the following matters may be commonly applied.

A second codeword generated by encoding base 2 data for the terminal by the base station may be transmitted from the base station to the terminal. In addition, the first data for the terminal may be delivered to the terminal by the repeater.

At least one of a time resource and a frequency resource used by the repeater to transmit the first data to the terminal may be variably determined by the base station. The hourly data rate for the phase repeater is

And hourly data for the terminal

T ⁽²⁾ is the time required for the transfer of the first data in the repeater, ci is the rate occupied by the first data in the first codeword, and P ₂ is Respectively, transmit power for the first and second codewords, ^ is a signal-to-interference ratio for the channel from the base station to the repeater, is a signal-to-interference ratio for the channel from the base station to the terminal, ^, Pi and P ₂ can be determined.

The repeater may be a first terminal, and the terminal may be a second terminal.

The first and second codewords may be generated by a prior interference cancellation technique. The first data and the second data may correspond to portions in which information to be transmitted for the terminal is partitioned by the channel coded output by one channel coder in the base station.

The foregoing general description and the following detailed description of the invention are exemplary and intended for further explanation of the invention as described in the claims.

Advantageous Effects

According to the present invention, when data is transmitted through a user-relay in transmitting data from a base station to a user equipment, there is provided a method for more efficiently utilizing radio resources and successfully delivering data. Can be. In addition, when the base station transmits data to the terminal, a method for configuring data to be transmitted through the user-relay and the base station to transmit data directly to the terminal may be provided. In addition, there may be provided a method of determining a resource, a transmission rate, etc. to be used by a user-relay to deliver data to the terminal, and a method of performing retransmission due to data decoding failure at the terminal side.

Effects obtained in the present invention are not limited to the above-mentioned effects, and other effects not mentioned above may be clearly understood by those skilled in the art from the following description. will be. [Brief Description of Drawings]

BRIEF DESCRIPTION OF THE DRAWINGS The drawings appended hereto are for the purpose of providing an understanding of the present invention and for illustrating various embodiments of the present invention and for describing the principles of the present invention together with the description of the specification.

1 is a diagram illustrating a wireless communication system including a base station, a repeater, and a terminal.

2 is a diagram illustrating a structure of a radio frame used in a 3GPP LTE system.

3 is a diagram illustrating a resource grid in a downlink slot.

4 is a diagram illustrating a structure of a downlink subframe.

5 is a diagram illustrating a structure of an uplink subframe.

6 is a configuration diagram of a wireless communication system having multiple antennas.

7 is a diagram for conceptually describing a multi-user environment.

8 is a diagram illustrating a flow of operation of information transmission through a user-relay in a multi-user environment.

9 illustrates data encoded in a bit connection based partial signal transmission scheme. FIG. 10 is a diagram for describing a partial interference transmission (SIC) partial signal transmission operation.

11 is a flowchart illustrating a data transmission / retransmission operation through a repeater in a partial signal transmission method.

12 is a diagram for explaining a step of cooperative communication through a user-relay. 13 is a diagram illustrating a wireless communication system including a base station apparatus, a repeater apparatus, and a terminal apparatus according to the present invention.

[Best form for implementation of the invention]

The following embodiments combine the components and features of the present invention in a predetermined form. Each component or feature may be considered to be optional unless otherwise stated. Each component or feature may be embodied in a form that is not combined with other components or features. In addition, some components and / or features may be combined to form an embodiment of the present invention. Of the operations described in the embodiments of the present invention The order can be changed. Some components or features of one embodiment may be included in another embodiment or may be replaced with corresponding components or features of another embodiment. In the present specification, embodiments of the present invention will be described based on a relationship between data transmission and reception between a base station and a terminal. Here, the base station has a meaning as a terminal node of a network that directly communicates with the terminal. Certain operations described as performed by the base station in this document may be performed by an upper node of the base station in some cases.

That is, it is apparent that various operations performed for communication with the terminal in a network including a plurality of network work nodes including a base station may be performed by the base station or other network nodes other than the base station. A 'base station (BS)' may be replaced by terms such as a fixed station, a Node B, an eNode B (eNB), and an access point (AP). The repeater may be replaced by terms such as relay node (RN) and relay station (RS). In addition, the term 'terminal' may be replaced with terms such as UE Jser Equiment, Mole le Station (MS), Mole le Subscriber Station (MSS), and Subscriber Station (SS).

Specific terms used in the following description are provided to help the understanding of the present invention, and the use of the specific terms may be changed to other forms without departing from the technical spirit of the present invention.

In some instances, well-known structures and devices may be omitted or shown in block diagram form centering on the core functions of the structures and devices in order to avoid obscuring the concepts of the present invention. In addition, the same components will be described with the same reference numerals throughout the present specification.

Embodiments of the present invention may be supported by standard documents disclosed in at least one of the IEEE 802 system, the 3GPP system, the 3GPP LTE and the LTE-Advanced (LTE-A) system, and the 3GPP2 system, which are wireless access systems. That is, steps or parts which are not described to clearly reveal the technical spirit of the present invention among the embodiments of the present invention may be supported by the above documents. In addition, all terms disclosed in this document may be described by the above standard document.

The following descriptions include code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), and 0rthogonal frequency (0FDMA). Division Multiple Access (SCD), Single Carrier Frequency Division Multiple Access (SC-FDMA), and the like can be used in various wireless access systems. CDMA may be implemented by a radio technology such as UTRA lni versa 1 Terrestrial Radio Access) or CDMA2000. TDMA may be implemented in a wireless technology such as Global System for Mobile Communications (GSM) / General Packet Radio Service (GPRS) / Enhanced Data Rates for GSM Evolution (EDGE). 0FDMA may be implemented by a wireless technology such as IEEE 802.il (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, E-UTRAC Evolved UTRA). UTRA is part of the UMTSCUniversal Mobile Telecommunications System (3GPP) 3rd Generation Partnershi Project (3GPP) long term evolution (LTE) is part of the Evolved UMTS (E-UMTS) using E—UTRA. Adopt SC-FDMA on the link. LTE-A (Advanced) is the evolution of 3GPP LTE. WiMAX can be described by the IEEE 802.16e standard (WirelessMAN—OFDMA Reference System) and the advanced IEEE 802.16m standard (WirelessMAN—OFDMA Advanced system). For clarity, the following description focuses on 3GPP LTE and 3GPP LTE-A systems, but the technical spirit of the present invention is not limited thereto. 2 is a diagram illustrating a structure of a radio frame used in a 3GPP LTE system. One radio frame includes 10 subframes, and one subframe includes two slots in the time domain. The transmission time of one subframe is defined as a transmission time interval (ΤΠ). For example, one subframe may have a length of 1 ms, and one slot may have a length of 0.5 ms. One slot may include a plurality of 0FDM symbols in the time domain. Since the 3GPP LTE system uses the 0FDMA scheme in the downlink, the 0FDM symbol represents one symbol length (period). One symbol may be referred to as an SC-FDMA symbol or a symbol length in uplink. A resource block (RB) is a resource allocation unit and includes a plurality of consecutive subcarriers in one slot. The structure of such a radio frame is merely exemplary. Therefore, the number of subframes included in one radio frame, the number of slots included in one subframe, or the number of 0FDM symbols included in one slot may be changed in various ways. 3 is a diagram illustrating a resource grid in a downlink slot. One downlink slot includes seven OFDM symbols in the time domain and one resource block (RB) is shown to include 12 subcarriers in the frequency domain, but the present invention is not limited thereto. For example, one slot includes 7 OFDM symbols in the case of a general cyclic prefix (CP), but one slot may include 6 OFDM symbols in the case of an extended CP. Each element on the resource grid is called a resource element. One resource block includes 12 × 7 resource elements. The number of N ^DLs of resource blocks included in the downlink slot depends on the downlink transmission bandwidth. The structure of the uplink slot may be the same as that of the downlink slot.

4 is a diagram illustrating a structure of a downlink subframe. Up to three OFDM symbols at the front of the first slot in one subframe correspond to a control region to which a control channel is allocated. The remaining OFDM symbols correspond to data regions to which a physical downlink shared channel (PDSCH) is allocated. Downlink control channels used in the 3GPP LTE system include, for example, a physical control format indicator channel (PCFICH), a physical downlink control channel (PDCCH), and a physical HARQ index. Physical Hybrid Automatic Repeat reQuest Indicator Channel (PHICH). The PCFICH is transmitted in the first OFDM symbol of a subframe and includes information on the number of OFDM symbols used for control channel transmission in the subframe. The PHICH includes a HARQ ACK / NACK signal as a response of uplink transmission. Control information transmitted through the PDCCH is referred to as downlink control information (DCI). The DCI includes uplink or downlink scheduling information or an uplink transmit power control command for a certain terminal group. The PDCCH includes a resource allocation and transmission format of a DL shared channel (DL-SCH), resource allocation information of an uplink shared channel (UL—SCH), paging information of a paging channel (PCH), system information on a DL-SCH, and a PDSCH. Resource allocation of upper layer control messages, such as random access responses transmitted to the network, a set of transmit power control commands for individual terminals in a certain terminal group, transmit power control information, and activation of voice over IP (VoIP) And the like. A plurality of PDCCHs may be transmitted in the control region. The terminal may monitor the plurality of PDCCHs. PDCCH is one or more It is transmitted as an aggregate of consecutive control channel elements (CCEs). CCE is a logical allocation unit used to provide a PDCCH at a coding rate based on the state of a radio channel. The CCE corresponds to a plurality of resource element groups. The format of the PDCCH and the number of available bits are determined according to the correlation between the number of CCEs and the coding rate provided by the CCEs. The number of CCEs used for PDCCH transmission is called a CCE aggregation level. In addition, the CCE combination level is a CCE unit for searching for a PDCCH. The size of the CCE combination level is defined by the number of adjacent CCEs. For example, the CCE combination level may be 1, 2, 4 or 8.

The base station determines the PDCCH format according to the DCI transmitted to the terminal, and adds a cyclic redundancy check (CRC) to the control information. The CRC is masked with an identifier called Radio Network Temporary Identifier (RNTI) according to the owner or purpose of the PDCCH. If the PDCCH is for a specific terminal, the cell-RNTKC-RNTI) identifier of the terminal may be masked to the CRC. Or, if the PDCCH is for a paging message, a paging indicator identifier (P-RNTI) may be masked to the CRC. If the PDCCH is for system information (more specifically, system information block (SIB)), the system information identifier and system information RNTKSI-RNTI may be masked to the CRC. In order to indicate a random access response that is a response to transmission of the random access preamble of the UE, random access -RNTKRA-RNTI may be masked to the CRC.

5 is a diagram illustrating a structure of an uplink subframe. The uplink subframe may be divided into a control region and a data region in the frequency domain. A physical uplink control channel (PUCCH) including uplink control information is allocated to the control region. In the data area, a physical uplink shared channel (PUSCH) including user data is allocated. In order to maintain a single carrier characteristic, one UE does not simultaneously transmit a PUCCH and a PUSCH. PUCCH for one UE is allocated to an RB pair in a subframe. Resource blocks belonging to a resource block pair occupy different subcarriers for two slots. It is said that the RB pair allocated to the PUCCH is frequency hopped at the slot boundary. Modeling of Multiple Antenna (MIMO) Systems

As shown in FIG. 6 (a), if the number of transmitting antennas is increased to ^ and the number of receiving antennas is increased to Λ ^, the theoretical channel is proportional to the number of antennas unlike the case where only a plurality of antennas are used in a transmitter or a receiver. The transmission capacity is increased. Therefore, the transmission rate can be improved and the frequency efficiency can be significantly improved. As the channel transmission capacity increases, the transmission rate can theoretically increase as the rate of increase ½ ·) is multiplied by the maximum transmission rate?.

[Equation 1]

/, = min (V _r , ^)

For example, in a MIM0 communication system using four transmit antennas and four receive antennas, a transmission rate four times higher than a single antenna system can be theoretically obtained. Since the theoretical capacity increase of multi-antenna systems was proved in the mid-90s, various technologies have been actively studied to lead to the actual data rate improvement. Several technologies have already been studied, such as 3G mobile communication and next generation WLAN. It is reflected in various wireless communication standards.

The research trends related to multi-antennas to date include the study of information theory aspects related to the calculation of multi-antenna communication capacity in various channel environments and multi-access environments, the study of wireless channel measurement and model derivation of multi-antenna systems, improvement of transmission reliability and improvement of transmission rate Research is being actively conducted from various viewpoints, such as research on space-time signal processing technology.

The communication method in a multi-antenna system will be described in more detail using mathematical modeling. It is assumed that there are ^ transmit antennas and ^ receive antennas in the system.

Looking at the transmission signal, if there are ^ transmission antennas, the maximum information that can be transmitted is ^. The transmission information may be expressed as follows.

[Equation 2]

_ I τ

S = ^ _j , 5 ₂ , · · ·, S _NT J Each transmission information ^S ^ ^S V ^S N _T ^ Transmission power may be different ᅳ Each transmission In this case, the transmission information whose transmission power is adjusted is as follows.

V V

\ ^S \ ， ^ * 2 ^S 2 ，… ， ^S N. _r J

In addition, s may be expressed as follows using a diagonal matrix ^ of transmit power. [Equation 4]

The weight matrix W is applied to the information vector s of which the transmission power is adjusted.

Consider the case where ^ transmission signals, ^ ² , ^"' , ^" ^^ are constructed. Weighting matrix

W plays a role of properly distributing transmission information to each antenna according to a transmission channel situation. ^x i ' ^{X 2} O ^x N _r can be expressed as follows using the vector X. [Equation 5]

Here, a means a weight between the / th transmit antenna and the / th information. w is also called a precoding matrix.

The received signal is y½? If there are two receiving antennas, the received signal of each antenna> ^ ^ ^'''' _« may be expressed as a vector as follows.

[Equation 6] In the case of modeling a channel in a multi-antenna wireless communication system, channels may be divided according to transmit / receive antenna indexes. The channel from the transmitting antenna to the receiving antenna / will be marked ^hi j S—. Note that in the order of the index, the receiving antenna index is first, and the index of the transmitting antenna is later.

6 (b) shows a channel from V _r transmit antennas to a receive antenna /. The channels may be bundled and displayed in the form of a vector and a matrix. In FIG. 6 (b), a channel arriving from a total of _τ transmitting antennas to a receiving antenna / may be represented as follows.

[Equation 7]

Accordingly, all channels arriving from r transmit antennas to ^ receive antennas may be expressed as follows.

Formula

H =

The real channel is added with Additive White Gaussian Noise (AWGN) after passing through the channel matrix Η. The white noise «1,« ² , ^'" ," ^ added to each of the _R reception antennas can be expressed as

【Number

The received signal may be expressed as follows through the above-described mathematical modeling.

[Equation 10]

On the other hand, the number of rows and columns of the channel matrix H indicating the channel state is determined by the number of transmitting and receiving antennas. The number of rows in the channel matrix H is equal to the number of receiving antennas, and the number of columns is equal to the number ^ of transmitting antennas. That is, the channel matrix Η is a matrix VypXA ^.

The rank of a matrix is defined as the minimum number of rows or columns independent of each other. Thus, the rank of the matrix cannot be greater than the number of rows or columns. The tank (ra «:( H)) of the channel matrix H is limited as follows.

[Equation 11]

rank H) ≤ min (V _r , N _R )

Another definition of rank is that when an eigenvalue decomposition of a matrix

Can be defined as the number of nonzero eigenvalues. Similarly, another definition of rank can be defined as the number of nonzero singular values when singular value decomposition. Therefore, the physical meaning of rank in the channel matrix is the maximum number that can send different information in a given channel. Multi-user -MIM0 behavior

Multiple user-MIM0 (MU-MIM0) refers to an operation in which a base station having multiple antennas serves a plurality of users (terminals) at the same time. When multiple users are served by one base station at the same time, the signal for one terminal may act as interference for the other terminal, and thus the overall system performance may be degraded. Therefore, in order for data transmission and reception according to the MU-MIM0 operation to be performed correctly, it is required to remove the interference between users. To this end, the base station may perform signal processing according to an interference cancellation technique for a signal to be transmitted to multiple users.

In the base station, each independent information block to be transmitted to each terminal Can be encoded as a codeword. The encoded codewords may be transmitted according to the interference cancellation scheme. For example, for a codeword transmitted from one base station to a plurality of terminals, the base station may transmit in a manner of eliminating interference in advance. By pre-subtraction of the signal transmitted to one terminal (U) to the other terminal (U ₂ ), the terminal (U ₂ ) can receive the signal from the base station as if there is no interference. A separate interference cancellation operation may not be performed, such as zero forcing-dirty paper coding (ZF-DPC), zero forcing (ZF), or the like.

The ZF-DPC will be described first. Assuming two terminals Ji and U ₂ ) simultaneously served by one base station, it can be said that the combined channel Η = [1 h ₂ ] of channel (hi) and channel (h2) of U ₂ . When LQ decomposition is performed on the synthesized channel H, it can be decomposed into a lower triangular matrix L and an orthogonal matrix Q as shown in Equation 12 below.

[Equation 12]

When MIM0 transmission is performed using a column of the matrix Q as a beamforming vector in Equation 12, only the lower triangular matrix L remains in the signal received by the terminal. If the base station knows all of the channel environment for each terminal, encoding can be performed by transmitting the encoded components without interference of the first row without interference of the first row. Will be. Here, when the bumping vector _Wi (ie, the beamforming vector for U is _Wl and the beamforming vector for U ₂ is W2) == for each terminal, the effective channel is represented by the following equation (13). It can be expressed as Accordingly, since the signal to one terminal may be transmitted after the interference from the signal to the other terminal is removed in advance, the corresponding terminal may correctly receive the signal from the base station without a separate operation of removing the interference.

[Equation 13]

Next, in the case of ZF beamforming, interference cancellation may be performed through a pseudo-inverse for the synthesis channel H for multiple users, as shown in Equation 14 below.

[Equation 14]

F = H ^H (HH ^H X "in Equation 14 denotes a Hermit matrix for the matrix X, and X- ¹ represents an inverse matrix for the matrix X. The matrix F of Equation 14 Each column becomes a beamforming vector for each terminal, that is, wf, and in this case, the effective channel for each terminal can be expressed by Equation 15 below. ]

One

i = k

0 i ≠ k In this case, the channel in each terminal is in the form of an identity matrix, and as a result, it is possible to receive a signal from which interference has been removed in advance. Repeater

Repeaters may be considered, for example, to extend high data rate coverage, improve group mobility, ad hoc network deployment, improve cell boundary yield and / or provide network coverage in new areas.

Referring back to FIG. 1, the repeater 120 plays a role of forwarding transmission and reception between the base station 110 and the terminal 132, and two types of links having different attributes in each carrier frequency band (backhaul link). And access links) apply. Base station 110 may include a donor cell. The intensifier 120 may be wirelessly connected to the radio-access network via the donor cell 110.

When the backhaul link between the base station 110 and the repeater 120 uses a downlink frequency band or a downlink subframe resource, the backhaul link is expressed as a backhaul downlink, When using an uplink frequency band or an uplink subframe resource, it may be expressed as a backhaul uplink. Here, the frequency band is a resource allocated in the frequency division duplex (FDD) mode, and the subframe is a resource allocated in the time division duplex (TDD) mode. Similarly, when the access link between the repeater 120 and the terminal 132 uses a downlink frequency band or a downlink subframe resource, it is expressed as an access downlink and uses an uplink frequency band or an uplink subframe resource. Can be expressed as an access uplink. Figure 1 shows the configuration of the backhaul uplink / downlink and access uplink / downlink of the FDD mode repeater.

The base station requires a function of uplink reception and downlink transmission, and the terminal requires a function of uplink transmission and downlink reception. On the other hand, the repeater requires all the functions of backhaul uplink transmission to the base station, access uplink reception from the terminal, backhaul downlink reception from the base station, and access downlink transmission to the terminal.

On the other hand, with respect to the use of the repeater's band (or spectrum), the case in which the backhaul link operates in the same frequency band as the access link is called an 'in-band', and a frequency band in which the backhaul link and the access link are different. The case of operating at is called out-band. In both in-band and out-band cases, terminals operating according to an existing LTE system (eg, Release-8) (hereinafter referred to as legacy terminals) must be able to access the donor cell.

Depending on whether the terminal recognizes the repeater, the repeater may be classified as a transparent repeater or a non-transparent repeater. A transparent means a case in which a terminal does not recognize whether it communicates with a network through a repeater, and a non-transient refers to a case in which a terminal recognizes whether a terminal communicates with a network through a repeater.

With regard to the control of the repeater, it may be divided into a repeater configured as part of a donor cell or a repeater controlling a cell by itself.

A repeater configured as part of the donor cell may have a repeater identifier (ID), but does not have a repeater's own identity. If at least a part of RRM (Radio Resource Management) is controlled by the base station to which the donor cell belongs, the repeater is configured as part of the donor cell (even though the remaining parts of the RRM are located in the repeater). do. Preferably, such a repeater may support the legacy terminal. For example, smart repeaters, decode-and-forward relays, and various types and types of L2 repeaters are two such repeaters.

In the case of a repeater controlling the cell by itself, the repeater controls one or several sals, and each cell controlled by the repeater is provided with a unique physical layer cell identity, and may use the same RRM mechanism. From a terminal point of view, there is no difference between accessing a cell controlled by a repeater and accessing a cell controlled by a general base station. Preferably, the cell controlled by this repeater may support the legacy terminal. For example, self-backhauling repeaters, L3 (third layer) repeaters, type-1 repeaters and type-la repeaters are such repeaters. The type-1 repeater is an in-band repeater that controls a plurality of cells, each of which appears to be a separate cell that is distinct from the donor cell from the terminal's point of view. In addition, the plurality of cells have their own physical cell IDs (as defined in LTE Release-8), and the repeater may transmit its own synchronization channel and reference signal. In the case of single-sal operation, the terminal may receive the scheduling information and HARQ feedback directly from the repeater and transmit its control channel (scheduling request (SR), CQI, ACK / NACK, etc.) to the repeater. In addition, to the legacy terminals (terminals operating in accordance with the LTE Release-8 system), the type-1 repeater appears to be a legacy base station (base stations operating in accordance with the LTE Release-8 system). That is, backward compatibility. Meanwhile, for terminals operating according to the LTE-A system, the type-1 repeater may be seen as a base station different from the legacy base station, and may provide a performance improvement.

The type-la repeater has the same features as the type-1 repeater described above in addition to operating out-band. The operation of the type-la repeater may be configured to minimize or eliminate the impact on L1 (Layer 1 layer) operation.

The type-2 repeater is an in-band repeater and does not have a separate physical cell ID and thus does not form a new cell. The Type 2 repeater is transparent to the legacy terminal, and the legacy terminal does not recognize the presence of the Type-2 repeater. Type-2 repeaters may transmit PDSCH, but do not transmit at least CRS and PDCCH. Hybrid Automatic Retransmission Request (HARQ) Behavior

The following HARQ operation may be applied as a control method for data reception failure. After transmitting one packet at the data transmission side, when the ACK signal is received from the data receiving side, a new packet is transmitted, and when the NACK signal is received, the previously transmitted packet can be retransmitted. In this case, a packet to which encoding according to a Forward Error Correction (FEC) function is applied may be retransmitted. Therefore, as a result of receiving and decoding one packet, the data receiving side transmits an ACK signal when decoding is successful, and transmits an NACK when decoding fails, and stores the received packet in a buffer. When the retransmission packet according to the NACK signal is received, decoding is performed in combination with the packet received in the buffer, thereby increasing the reception success rate of the packet.

The HARQ scheme can be classified into a synchronous HARQ scheme and an asynchronous HARQ scheme according to the timing of retransmission. In the synchronous HARQ scheme, when initial transmission fails, subsequent retransmissions are performed at a time point determined by the system. For example, when retransmission is performed every fourth time unit (for example, a subframe) after the initial transmission failure, it is not necessary to inform the receiving side of the information on the time of retransmission. Therefore, when the NACK signal is received at the data transmission side, the packet is retransmitted every fourth time until the ACK signal is received. On the other hand, according to the asynchronous HARQ scheme, information on a time point for retransmission is separately scheduled. Therefore, the retransmission timing of the packet acknowledging the NACK signal may be changed by various requirements such as channel state.

In addition, it may be classified into an adaptive HARQ scheme and a non-adaptive HARQ scheme according to whether the channel state is reflected about the amount of resources used for retransmission. In the non-target HARQ scheme, the MCS level of the retransmitted packet, the number of resource blocks used, and the like are determined as determined at initial transmission. For example, if the transmitting side transmits data by using eight resource blocks during initial transmission, the retransmission is performed using eight resource blocks in the same way. On the other hand, the red-eye method is a method in which a packet modulation method, the number of resource blocks used, and the like vary according to channel conditions. For example, even when the transmission is initially performed using eight, it may be retransmitted later using a larger or smaller number of resource blocks depending on the channel state. In the above-described data packet transmission operation through HARQ, the transmitting end converts the data packet into sub-packets having a predetermined size, and initial transmission and retransmission may be performed in units of sub packets. The receiving end may attempt to decode the data packet by combining several subpackets.

Several subpackets used for initial transmission and retransmission by the HARQ scheme are generated from one codeword packet. In this case, the generated subpackets can be distinguished by the length of the subpackets and the start positions of the subpackets. This distinguishable sub-packet is called a redundancy version (RV). The receiving end may attempt to decode the entire codeword by receiving and combining different RVs. For example, the HARQ operation may be performed by receiving only the difference between the entire codeword packet to be received and the subpacket already received, and attempting decoding. The HARQ operation of the incremental redundancy (IR) scheme is performed. It can be called an operation. Partial Signaling Through Repeaters in a Multi-User Environment

7 is a diagram for conceptually describing a multi-user environment. In the example of FIG. 7, it is assumed that the base station has multiple antennas and can support MU-MIM0 transmission, and it is assumed that terminals U _{2 (...} ) Have a single antenna. However, this assumption is merely illustrative for clarity of explanation, and the principles of the present invention described below may be equally applied to the terminal (s) with multiple antennas.

Referring to FIG. 7A, a plurality of terminals (, U ₂ ,...) May simultaneously receive signals from the base station BS. The channel to is called lu and the channel all to U ₂ can be called h ₂ . For example, it is assumed that the channel state is good because it is located close to the base station, whereas U ₂ is located at the cell edge relative to the base station. In order to guarantee data transmission to a terminal having a poor channel condition, a base station may transmit a signal at a higher power, but a problem of causing interference may occur. To solve such a problem, various repeaters as described above may be used. Can be introduced. However, when a new repeater is installed in the network, a separate resource must be used. Consideration may be given to making the function of a repeater. Such a repeater may be referred to as a user-relay, and the user-relay may correspond to a type-2 repeater as described above. That is, the user-repeater is transparent to the terminal receiving the data.

Fig. 7 (b) functions as this user-relay and shows that 1) ₂ receives data from the base station via I. As described above, data transmission is performed through cooperation between terminals in a multi-user environment, thereby improving overall transmission capacity and increasing resource efficiency. For example, compared to other terminals, the terminal has a better channel environment with the base station (!! Can function as a user-relay, and can assist data transfer to another terminal J ₂ with poor channel environment). Specifically, by passing the data to be delivered in the same time, it is possible to receive data transmitted from the base station to U ₂ from the base station. The data it receives, following receiving their data from the base station to U ₂ to u ₂ Can give From the standpoint of u ₂ , data about itself may be obtained through data received directly from the base station and data received through ^. Such a data transmission method may be referred to as a partial signal transmission method. In order for information delivery using a user-relay to be performed in a multi-user environment as described above, a scheme for encoding information bits to be delivered to each user at the base station needs to be determined. Hereinafter, various embodiments of the present invention for the information bit encoding scheme in the base station and the information transfer operation through the user-relay will be described in detail.

8 is a diagram illustrating a flow of operation of information transmission through a user-relay in a multi-user environment. In FIG. 8, for the sake of clarity, the remaining terminals of the multi-user environment except for this and # ₂ are not shown. However, the scope of the present invention is not limited thereto, and even when MU-MIM0 transmission is performed for two or more terminals, and any one terminal functions as a user-relay for another terminal (s). The principles of the present invention can be equally applied. In FIG. 8, UE denotes a terminal functioning as a user-repeater, U ₂ denotes a terminal serving as a destination of information transmission, and U ₂ may also be referred to as a destination user. Referring to FIG. 8, the base station encodes data for each terminal (S810), transmits encoded data to each terminal (and U ₂ ) (S820), and restores the data received at Ui (S830). , the transmission data for the U ₂ among the restored data to and U ₂ (S840), the U ₂ by using the signal received in step S820 and S840 to restore the data for their own (S850). The specific operation in each step will be described below.

Step S810 is a data encoding step. The base station (BS) can encode the data for the terminal (^), which functions as a user-relay, and the data for the destination user (U ₂ ) to receive the information therethrough. Specifically, as shown in FIG. Data encoding for may be performed.

FIG. 9 (a) shows data encoded with respect to FIG. 9 (b) shows data encoded with respect to U ₂ . The information bit for denotes ^ and the information bit for U ₂ denotes ¾. ¾ is further divided into _two bits: the information bits received by U ₂ via channel (h ₂ ) directly from the base station (BS) and the information bits carried by channel (h ₁₂ ) from the user-relay. Here, for example, ₂ may be configured as an information bit of a portion of (ie, ¾, ₂ overlaps with a portion of), or ¾. ₂ may be configured as a separate information bit that is distinct from ^ (i.e. and ¾ _{, 2} do not overlap). For example, S _{2 and} r may correspond to systemic bits, and ¾ and ₂ may correspond to parity bits. Or, for example, S ₂ j and ¾, ₂ may correspond to partitioning the output () from the same channel coder into the first part and the second part (ie, ¾). One of the partial fractions of S _{2> 1} and the other corresponds to ₂ ).

As shown in FIG. 9 (a), the information bit, 2 for U ₂ may be concatenated with the information bit Si for ^ and encoded as one codeword. Such an encoding method may be referred to as a bit concatenation method, and the partial signal transmission method proposed by the present invention may be referred to as a bit connection based partial signal transmission method.

As shown in FIG. 9 (a), one codeword encoded by concatenating ^, ¾, and ₂ may be expressed as ¾. Bits for ^ and ¾ _{, 2} in full codeword ¾ It can be the percentage that each of (1 eu «) and« (wherein, o≤ ^a <i). If the transmission power per bit is set to be the same, and may correspond to the transmission power ratio.

As shown in FIG. 9 (b), the information bit ^ for U ₂ may be encoded into one independent codeword ¾.

In step S820, the base station may transmit the codewords ¾ and X ₂ encoded in step S810 to each terminal (and U ₂ ). Step S820 may also be expressed as a step in which the base station broadcasts data to each terminal in a first transmission phase. When the base station transmits codewords ¾ and ¾ to the terminal and U ₂ , respectively, the interference for each terminal may be removed in advance by applying an interference cancellation scheme such as the ZF-DPC or the ZF scheme as described above. .

If the transmit power allocated to the codeword transmitted to Ui is called and the transmit power allocated to the codeword X ₂ transmitted to U ₂ is P ₂ , the sum of ^ and P ₂ is the maximum transmit power P _BS of the base station. Can't go over

The signals received at each of the terminals ¾ and U ₂ in the first transmission step may be expressed by Equation 16 below.

[Equation 16]

= ^ h ₂ w ₂ x ₂ (s _{2 l} ) + n _x , where _yi ⁽¹⁾ and y ₂ ⁽¹⁾ in Equation 16 represent signals received at ^ and U ₂ in the first transmission step, respectively. F and P ₂ denote transmit powers allocated to codewords and respectively. Xl (Si, S ₂ , ₂ ) denotes a codeword encoded by concatenating _Sl , S ₂ , ₂ , and (, denotes the encoded codeword, ^ and h ₂ represent between ¬ and U ₂ from the base station, respectively. ^ And w ₂ denote beamforming vectors to Yi and U ₂ , respectively. The beamforming vector may be determined as described exemplarily in the ZF-DPC or ZF technique, which is the aforementioned pre-interference cancellation technique. And n ₂ denote Additive White Gaussian Noise (AWGN) at ^ and U ₂ , respectively.

In step S820, the transmission from the base station and the transmission from the base station to U ₂ may be performed at the same time, or may be performed at different times. In addition, the above-described first transmission step is a term for expressing the order in which the operations are performed in the overall operation in which information transmission to the destination is performed through the user-relay.

Step S830 is a step in which each of these and 1) ₂ recovers (or decodes) data from the signal received in the first transmission step. ^ May decode codeword ¾ from the signal received in the first transmission step, and U ₂ may decode codeword ¾ from the signal y ₂ ⁽¹⁾ received in the first transmission step.

In the case of ^, only the information corresponding to the ratio of ^ among the restored information amount is own information, and the information corresponding to the ratio of ^ is information about the other terminal U ₂ . Accordingly, the amount of information that can obtain information about itself in the first transmission step in ^ and U ₂ can be expressed by Equation 17 below.

[Equation 17]

In Equation 17, Ji and ^ are each | h _lWl l ² / N ₀ and Ih ₂ w ₂ | ² / N ₀ . Here, N ₀ means a variance of r and n _{2 which} are GN with respect to U1 and U2 described in Equation 16 above.

In step S840, information forwarding is performed in a second transmission phase.

As a user-relay, it can extract information (i.e., ¾. ₂ ) for another terminal U ₂ corresponding to the ratio of ^a from the amount of information recovered from the base station in the first transmission step. The data S ₂ and ₂ for the extracted U ₂ are transmitted in the second transmission. You can pass from step ₂ to u ₂ .

Here, Ui may transmit the extracted data (.2) to 1½ by performing modulation on XR. Since ¾ contains the data ¾, ₂ of U ₂ as it is, it can be expressed as X _R (S ₂ , ₂ ). The modulation scheme applied to ¾ _{, 2} may be indicated from the base station. For example, a modulation scheme to be applied to data (¾ _{, 2} ) to be transmitted to another terminal 1 1 ₂ may be predetermined by pre-signal exchange between the base station and the user-relay (). The data to be transmitted to the other terminal (U ₂ ) in the codeword ¾ generated by concatenating and encoding the data (^ ;！ for U) and the data ( _{, 2} ) to be transmitted to the other terminal (U2). ¾ _{, 2} ) may include information indicating a modulation scheme to be applied by 1.

In addition, the user-relay (! ^) May use the maximum transmit power ί¾ to maximize the efficiency of the transmission to the destination user (U ₂ ). In this case, the signal received by U ₂ is represented by the following equation (18). Can be.

[Equation 18]

In Equation 18, y ₂ ⁽²⁾ represents a signal that U ₂ receives in the second transmission step. Ρυι represents the transmit power allocated to x _R. x _R (s ₂ , ₂ ) represents a signal in which data (s ₂ , ₂ ) transferred from to U ₂ is modulated by x _R by ^. h ₁₂ means the channel between this and U ₂ . n ₁₂ means AWGN on h ₁₂ .

The amount of information U ₂ obtains from the received signal as shown in Equation 18 can be expressed as Equation 19 below.

[19]

In Equation 19, R ₂ ⁽²⁾ means the amount of information that U ₂ obtains in the second transmission step. In addition, G ² means lh ₁₂ l ² / N ₀ .

From the repeater as in (U) a destination user (u ₂₎ data (s _{₂ 2.)} Passes, - the user In order to increase the efficiency of information transmission, the second transmission step may be variably determined according to the amount of information to be transmitted. In the case of considering the variable transmission step, the time required for the user-repeater (!!) to transmit information can be expressed as Equation 20 below.

[Equation 20]

In Equation 20, t ⁽¹⁾ means time spent during the first transmission step, and t ⁽²⁾ means time spent during the second transmission step. Here, the amount of information that can obtain data for the first transmitting user (U ₂ ) from the base station in the user-relay (U)

And destination user u ₂ is delivered from the user-relay u during the second transmission phase.

The time required for the second transmission step may be determined relative to the time required for the first transmission step, depending on the ratio of the amount of information logf 1 + C γ / 12 ₇ capable of acquiring data. For example, the time spent during the first transmission step is 4 subframes, and (the amount of information of data for the destination user U ₂ obtained at the user-relay in the first transmission step) / (the destination in the second transmission step) If the information amount of data acquired by the user U ₂ ) = 1/2, the second transmission step may be set to require 2 subframes. Herein, the amount of information obtained may vary according to the state of the channel and / or h ₁₂ ), and accordingly, the time required for the second transmission step may be variably determined.

Alternatively, when the time required for the first transmission step and the second transmission step is fixed, the size of the frequency resource used for information transmission may be variably determined. That is, the size of the frequency resource to be used in the second transmission step may be variably determined according to a principle similar to the variable transmission time described above. For example, the size of the total frequency resources used in the first transmission step (i.e., and the size of the frequency resources used to transmit both ¾, ₂ ) is 10 resource blocks (RBs), and (the first transmission In stage User-repeater Λ) if the destination user (U ₂₎ information amount of data) / (the second transfer destination user (information volume of data to be U ₂₎ is obtained in step) = 1/2 for obtaining from a second transmission step The frequency resource used in may be set to five RBs. Here, the amount of information obtained may vary according to the state of the channel (and / or h ₁₂ ), and accordingly, the size of the frequency resource used in the second transmission step may be variably determined.

Here, the data that Ui will pass to U ₂ S ₂ . ₂ corresponds to information bits generated and encoded by the base station (BS), and Ui does not perform any processing other than the above-described modulation and transmission for ¾, ₂ . That is, the user-repeater (i is only forwarded to the AS line, U ₂ having received the data (¾, ₂₎ to other terminal (U ₂₎ at the base station.

Step S850 is a step in which U ₂ recovers (or decodes) data for itself using the signal received in the first transmission step and the signal received in the second transmission step. The user-relay (! ^) Receives data only in the first transmission step, while the destination user U ₂ receives data in both the first transmission step and the second transmission step. The destination user U ₂ receives the first data. By concatenating the signal (y ₂ ⁽¹⁾ ) received in the transmission step and the signal (y ₂ ⁽²⁾ ) received in the second transmission step, it is finally connected to itself in a joint-decoding manner. Data can be restored.

Accordingly, the data transmission efficiency per time in each terminal (U1 and U2) finally can be expressed by the following equation (21).

[Equation 21]

(l-) log (l + ^ _ri )

t ^il) + t ⁱ²⁾

(i) 2)

(2)

C ₂ ( _y RP ₂ ) = ^■ 2

t ⁽⁾⁾ ₊ t ^{(2) R2}

t (1)

_{_{log (l + P 2/2}} ) + a-log (l + ^ i)} in the expression (21), and C ₂ denotes the transmission efficiency for each, and U _2. P ₁ P ₂ and ^ may be determined according to the amount of information required. It may be in the repeater (data transmitted to the U determine the rate of data to be delivered to the destination user (U2) also, - that is, the transmit power ^ and Ρ ₂ and the user at the base station to the transmission efficiency, and U ₂ to increase. From the viewpoint of the destination user υ ₂ , the data received in the first transmission step is S _2,! , And the data received from the user-relay (^) in the second transmission step is S ₂ , _2. As described above, , ₂ may be configured as part of the information bits of ^ (ie

¾, ₂ duplicate part of ^). In this case, since U ₂ performs data decoding using overlapping information, the decoding success rate may be increased compared to receiving data directly from the base station only when the channel condition is not good, and more robust data restoration may be performed. Can be. Alternatively, ¾, ₂ may be configured as a separate information bit distinguished from? ^ (That is, S2J and ₂ do not overlap). In this case, U ₂ can receive an appropriate amount of data through the direct channel from the base station and the channel from the user-relay, so that the amount of received information can be improved.

In the multi-user environment as described above, in a partial signal transmission method through a user-relay, data (or a part of data) for a terminal U ₂ having a relatively poor channel state may be a terminal having a good channel state (! It is possible to improve the transmission efficiency by transmitting it through the terminal. While satisfying, the extra channel capacity can be used to carry data for the other terminal (U ₂ ). In this case, since the data for the other terminal (u ₂ ) is transmitted in one codeword in connection with the data for the terminal having a good channel state, the data can be restored in the absence of interference during information restoration. , by taking into account a variable transmission time in the data transfer process, when the channel between the terminals good enough, the time is shorter, the transmission efficiency used in the information transmission is higher. MS (u ₂₎ is the channel condition is not good is their Receiving data for a through a direct channel from a base station and a channel from a user-relay may lead to an improvement in the amount of received information and / or an improvement in the decoding success rate.

In addition, the present invention is applicable in a multi-user environment using multiple antennas. In addition, by allowing all users to act as relays in some cases without using a separate repeater, it is possible to ensure the quality of service (QoS) of users outside the cell in a poor channel state. In addition, by using the partial signal transmission method described in the present invention, even in HARQ data retransmission, the base station transmits the retransmission data packet part to the destination user together with the data of the user-relay, so that the user instead of the base station at the time of data retransmission The repeater may deliver the retransmitted data packet directly to the destination user. HARQ operation via user-relay

The user-relay means a repeater in which one terminal helps another terminal rather than a fixed repeater, and such cooperative communication through the user-relay may be referred to as cooperative communication between terminals. Such a user-relay may correspond to the type-2 repeater described above.

When such a user-relay is used, the destination node (or destination user) does not recognize the presence of the repeater. Therefore, no information is exchanged in advance between the relay and the destination node, and no feedback on the channel status is reported from the destination node to the relay. That is, without the information on the channel between the repeater and the destination node, the repeater transmits data to the destination node. That is, data transfer from the repeater to the destination node must be performed in an open-loop fashion. User—When partial signal transmission through a repeater is applied, hh _{2, which} is a channel from a source node (ie, a base station) to each terminal, may be determined by channel state information feedback reported from each terminal. The channel h ₁₂ between the repeater (1!) And the destination node (U ₂ ) can be determined by the average characteristics of the channel rather than reflecting the actual channel environment.

As described above, when partial signal transmission is performed through the user-relay in the open-loop manner, there is a probability that communication outage occurs, and in order to correct such an error, a HARQ scheme retransmission operation may be applied. Hereinafter, various embodiments of the present disclosure will be described with respect to a resource allocation scheme and a HARQ operation scheme capable of obtaining a maximum data rate when the open-loop data transfer is performed through a user-relay.

In the embodiments of the present invention described below, the bit connection-based partial signal transmission scheme proposed by the present invention may be applied as a partial signal transmission scheme through a repeater, or other general partial signal transmission schemes may be applied. . The general partial signal transmission method refers to a method of transmitting data that can be directly transmitted in consideration of channel conditions from a source node to a destination node, and additionally transmitting data from a repeater to a destination node. The data to be transmitted from the repeater to the destination node is provided by the source node, which may be transmitted directly to the repeater, or the repeater may overhear the data transmitted from the source node to the destination node. Overhearing means that the relay overhears the data that the source node sends to the destination node.

A partial signal transmission method of a successive interference cancellation (SIC) method among the partial signal transmission methods will be described as an example. According to the SIC partial signal transmission scheme, a signal may be transmitted from a source node to a destination node in the following order.

10 is a diagram for explaining an SIC scheme partial signal transfer operation.

First, at the source node S, a basic layer and a superposed layer are superimposed and superimposed on the relay node R and the destination node D at the same time. Here, the base layer (b) corresponds to a portion directly transmitted from the source node to the destination node, and the overlap layer (SC) passes through the repeater to the destination node. Corresponds to the delivered part. When performing overlapping coding at the source node, the ratio of the signal power magnitudes of the base layer (b) and the overlap layer (sc) may be determined using the channel information between the source node and the repeater and the channel information between the source node and the destination node. Can be.

In the repeater, the overlap layer (sc) portion may be detected by first detecting and erasing the portion of the base layer (b) from the signal received from the source node. The repeater may deliver the overlap layer (SC) portion to the destination node.

The destination node detects the portion of the base layer (b) by receiving and detecting the portion of the overlap layer (SC) transmitted from the repeater and erasing the detected portion of the overlap layer (SC) from the signal (b + sc) received from the source node. can do.

The total data rate R _tot obtained in the SIC partial signal transfer operation is expressed by Equation 22 below.

[Equation 22]

sr

= log (l + right JR ₂ = log (l + r _rd )

In Equation 22, R _b is a transmission rate for the base layer (b), R _s is a transmission for the overlapping layer (sc), and ¾ is a transmission rate between the relay and the destination node.

^ Represents a Signal to Noise Ratio (SNR) for each channel. Ysd is the SNR for the channel between source node (S) and destination node (D), is the SNR for the channel between source node (S) and repeater (R), and ^ rd is the repeater _(R) and destination node. ( _D ) SNR for the channel in between. "Means the ratio of the base layer (b) and the overlapping layer (sc),""is assigned to the base layer (b),""is assigned to the overlapping layer (sc), respectively. In Equation 22, the base layer Since (b) is detected at both the repeater and the destination node, R _b , the transmission rate for the base layer (b), is determined as the minimum of the transmission rate for the repeater and the transmission rate for the destination node, and overlaps from the repeater to the destination node. The time taken to transmit the layer sc is determined according to the ratio of R _s and R ₂ .

Rate control may be performed at the source node to reduce the amount of information, transmission time, etc. and increase the overall transmission rate (^) from the relay to the destination node. The rate control may be performed based on channel information between the source node and the repeater, channel information between the source node and the destination node, and channel information between the repeater and the destination node. As described above, the SIC partial signal transmission method is required to transfer information from the repeater to the destination by specifying a rate capacity between the repeater and the destination node when the source node knows all information about the entire channel. By determining the time it takes to increase the overall rate. That is, the SIC partial signal transmission method can increase the overall data rate through precise data rate control in a closed-loop environment.

However, in the cooperative communication environment through the user-relay as described above, the destination node is not aware of the existence of the user-relay, and no feedback on the channel state is reported. That is, the repeater transmits data to the destination node in an open-loop manner without information about the channel between the relay and the destination node. In this case, since the source node cannot measure the rate capacity between the user-relay and the destination node, it may be difficult for the source node to determine the rate in advance and assign it to the repeater.

The present invention proposes a method for obtaining maximum transmission in performing cooperative communication through a user-relay in an open-loop environment. Specifically, considering the probability of outage according to the average characteristics of the channel in the open-loop environment between the user-relay and the destination node, the optimal resource for the source node to be used for data transfer from the repeater to the destination node ( Time resources and / or frequency resources) Proactively assigned, the repeater can perform the transmission / retransmission procedure. Alternatively, the source node may designate a resource to be used for data transmission / retransmission from the repeater to the destination node, and may inform the relay before the transmission / retransmission is performed.

The partial signal transmission method through the user-relay may be a bit connection-based partial signal transmission method proposed in the present invention, the above-described SIC partial signal transmission method or other general partial signal transmission method. In the following description, for the sake of clarity, the SIC partial signal transmission scheme in an open-loop environment will be described as an example, but the present invention is not limited thereto, and the same principles proposed by the present invention can be applied to various partial signal transmission schemes. Can be.

In addition, since there is a possibility that communication outage occurs between the relay and the destination node in the partial signal transmission method in the open loop environment, it may be considered to support HARQ transmission / retransmission for error correction. . In this HARQ operation, the destination node may correct an error by attempting decoding by combining accumulated data subpackets according to an incremental redundancy (IR) scheme.

Hereinafter, in transmitting / retransmitting data in an open-loop environment between a user relay and a destination node in a HARQ scheme, a source node controls a transmission rate based on a probability of a communication outage, and time-varying for each transmission step. Therefore, the (time-variant) channel characteristics will be described in the room to determine the best resource to the full rate to the maximum, while meeting the constraints _(a _ou t ge constraint) of the communication disruption. In particular, the source node allocates scheduling information for data transmission from the repeater to the destination node based on the probability of communication loss, and also schedules information for HARQ retransmission when data transmission from the repeater to the destination node fails. Can be assigned. In this case, the scheduling information may include a location and / or amount of time and / or frequency resources, a modulation and coding scheme applied to transmission / retransmission, and the like.

If the retransmission scheduling information of the repeater is specified by the source node, if the destination node fails to decode the data and sends a NACK to the source node, the repeater overhears the NACK and the source node. The data subpacket may be retransmitted to the destination node according to the retransmission scheduling information designated by. At the source node, the data to be sent from the relay to the destination node For the part, even if a NACK is received, retransmission is not performed. If the destination node succeeds in decoding the data and transmits an acknowledgment (ACK) to the source node, if the repeater overhears the ACK, the repeater does not use the resource for retransmission specified by the source node. When the ACK is received at the source node, new data can be transmitted.

The manner in which the source node designates a resource to be used for transmission / retransmission of the repeater may be applied when the repeater is a type-2 repeater (for example, the user-relay described above).

11 is a flowchart illustrating a data transmission / retransmission operation through a repeater in the partial signal transmission method.

In operation S1110, the source node S may transmit data to the relay R and the destination node D. FIG.

Some of the data transmitted to the repeater in step S1110 may include data to be delivered to the destination node. For example, according to the above-described bit connection based partial signal transmission scheme, the data transmitted to the repeater may be data in which the data for the repeater (S and data (, ₂ ) for the destination node) are encoded in the bit connection scheme. Alternatively, according to the above-described SIC-based partial signal transmission scheme, the data transmitted to the repeater may be data coded by overlapping the base layer and the overlap layer (b + sc), for example, transmitted to the destination node in step S1110. The data may correspond to data (^ ;!) for the destination node according to the bit-connection based partial signaling scheme, and data in which the base layer and the overlapping layer (b + sc) are overlapped according to the SIC based partial signaling scheme. It may also correspond to.

In addition, when the same data is transmitted to the repeater and the destination node in step S1110, the repeater may overhear the data transmitted from the source node to the destination node. A circle indicated by a dotted line in step S1110 indicates that the repeater can overhear data transmitted from the source node to the destination node. Alternatively, the source node may broadcast data to the relay and destination nodes. Alternatively, in step S1110, the source node may separately transmit data to the relay and the destination node.

In step S1120 the repeater goes from the data received in step S1110 to the destination node. It is possible to detect the data to be ^delivered,. For example, according to the bit connection based partial signaling scheme, the repeater may detect data ( _{, 2} ) for the destination node. or,

According to the SIC-based partial signal transmission scheme, the repeater may detect an overlap layer (sc) portion.

In operation S1130, the destination node may store the data received in operation S1110 in a buffer.

In step S1140, the repeater may deliver data to the destination node. For example, the data transmitted by the repeater to the destination node may correspond to data for the destination node (¾ _{, 2} ) according to the bit connection based partial signaling scheme, and according to the SIC based partial signaling scheme, the overlapping layer ( sc).

In addition, in step S1140, scheduling information for determining a transmission resource, a transmission rate, a modulation scheme, and the like used by the repeater to transmit data to the destination node may be previously designated by the source node. Alternatively, scheduling information may be transmitted to the repeater by the source node prior to the transfer operation of the repeater. A detailed method of determining scheduling information to be applied to data transmission of the relay by the source node will be described in detail later.

In operation S1150, the destination node may attempt data decoding based on the data received from the source node in step S1110 and the data received from the repeater in step S1140. For example, according to the bit connection-based partial signal transmission scheme, the destination node performs joint decoding by concatenating the data (S ₂ ) received from the source and the data (¾ _{, 2} ) received from the repeater to perform data decoding on the self. Or, according to the SIC-based partial signal transmission scheme, the destination node receives the base layer received from the source and the overlap layer received from the relay in the overlap coded data (b + sc). The base layer (b) can be detected by erasing (sc).

In step S1160, when the destination node fails to decode as a result of decoding in step S1150, NACK information may be generated and transmitted to the source node. When the repeater is a type-2 repeater such as a user-relay, the destination node cannot recognize the repeater, and thus the destination node cannot transmit the NACK information to the repeater. In this case, the repeater may overhear the NACK information transmitted from the destination node to the source node. step A circle indicated by a dotted line in SI 160 indicates that the repeater may overhear NACK information transmitted from the destination node to the source node.

In step S1170, the relay node may retransmit the data to the destination node according to the HARQ scheme. In this case, the retransmitted data may be an RV transmitted in an IR manner with respect to the data transmitted in step S1140.

In addition, in step S1170, scheduling information for determining a transmission resource, a transmission rate, a modulation scheme, and the like used by the repeater to retransmit data to the destination node may be previously designated by the source node. Alternatively, scheduling information may be transmitted to the repeater by the source node prior to the retransmission operation of the repeater. A detailed method of determining scheduling information to be applied to data retransmission of the repeater by the source node will be described in detail later.

If data decoding of the destination node succeeds in S1150, steps S1160 and S1170 may not be performed and the process may proceed directly to step S1180.

Alternatively, when decoding fails even when the destination node uses data received in step S1170, steps S1160 and S1170 may be performed again.

In step S1180, when the destination node succeeds in decoding the data, the ACK information may be generated and transmitted to the source node. When the repeater is a type 1 2 repeater such as a user-relay, the destination node cannot recognize the repeater, and thus the destination node cannot transmit the ACK information to the repeater. In this case, the repeater may overhear the ACK information transmitted from the destination node to the source node. The circle indicated by the dotted line in step S1180 indicates that the repeater can overhear the ACK information transmitted from the destination node to the source node.

When the relay receives (or overhears) the ACK, resources allocated from the source node for HARQ retransmission are not used. Meanwhile, when the source node receives the ACK, the source node may transmit new data to the destination node.

Meanwhile, in step S1110, ACK / NACK information may also be transmitted for data received by the repeater and the destination node, but this is omitted for clarity. In the present invention, it is assumed that the data transmission of step S1110 is received without error, or even if the data transmission of step S1110 is finally received without error through an operation such as HARQ retransmission. 12 is a diagram for explaining a step of cooperative communication through a user-relay. 12 (a) shows a broadcasting phase in which a source node transmits signals to a relay and a destination node. 12 (b) shows a forwarding phase in which a relay delivers a signal to a destination node. FIG. 12 (c) shows a case in which a decoding result (ACK / NACK) of a signal received at a destination node is transmitted and NACK. Indicates HARQ operation phase (HARQ operation phase) is performed HARQ retransmission (ReTx) is started.

Hereinafter, a method of determining an optimal resource, transmission rate, MCS, etc. to be used for transmission / retransmission from the repeater to the destination node in consideration of the probability of communication outage between the repeater and the destination node will be described in detail. . The scheduling information to be used for transmission / retransmission from the repeater determined by the source node to the destination node may be predetermined and known to the repeater.

In the following example, the SIC-based partial signal transmission scheme will be described as an example. However, the present invention is not limited thereto, and according to a similar principle with respect to other partial signal transmission schemes, a transmission resource and a transmission rate to be used by the repeater in the source node may be determined.

First, in the broadcasting step of FIG. 12A, the source node may generate data X to be transmitted by overlapping coding the base layer () and the overlap layer (x _sc ) as shown in Equation 23 below.

[Equation 23]

1 1

X 二 (la) x _h + ax _sc where a = <a≤ \

¾ = min log O + (1-c) 7 _sd I log (l +

R _s = \ g (\ + a _Ysr )? ₂ = log (l + ^)

In Equation 23, "means a ratio of a base layer (x _b ) and an overlapping layer (x _sc ), and« is assigned to the overlapping layer ( _Xsc ) in the base layer ( _Xb ), respectively.

^ d is the SNR for the channel between source node (S) and destination node (D), is the SNR for the channel between source node (S) and repeater (R), and ^ ra? Is the SNR for the channel between the repeater _R and the destination node D. R _b is the transmission rate for the base layer (b), R _s is the transmission for the overlapping layer (sc), and R ₂ is the transmission rate between the relay and the destination node.

In the delivery step of FIG. 12 (b), the repeater decodes the signal received from the source node (or overheared), extracts data to be delivered to the destination node (eg, an overlap layer (x _sc )), and Can be passed to the destination node.

Here, since the channel between the repeater and the destination node is an open-loop environment, the resources (time resource and / or frequency resource) that the repeater will use to transmit data to the destination node may be pre-allocated by the source node. have. For example, the time resource (T ₂ ) that the repeater will use for transmission to the destination node is predetermined by the source node, and since the source node does not know the channel state accurately, it can obtain the average channel information between the repeater and the destination node. The optimal resource can be determined based on the probability of outage.

Equation 24 below shows a probability of occurrence of communication outage in the delivery step of FIG.

[Formula 24] t (2) ⁱ R ₂ <R _s / T ₂ ] ≤S

R ₂ and R _s in Equation 24 are as defined in Equation 23. remind According to Equation 24, based on R _s , the amount of information per unit time that the repeater should send. The probability of occurrence of communication loss (P _{out (2)} ) according to T _{2, which} is a time resource that the repeater uses for transmission to the destination node, can be defined. ² is a reference value for the probability of a communication failure (outage) for determining whether a communication failure occurs in the delivery step of FIG. 12 (b), and SNR _RD means average SNR information between the relay and the destination node. By arranging Equation 24 with respect to ¾, the following Equation 25 can be derived.

[Equation 25]

2 log ₂ [l-SNR ^ ln (l-¾)]

Based on Equation 25, a transmission rate ^ 2 at which the repeater transmits a signal to a destination node in the transmitting step of FIG. 12 (b) may be determined as in Equation 26 below.

[Equation 26]

As shown in the HARQ operation step of FIG. 12 (c), if an error occurs in a signal transmitted from the repeater to the destination node during the time resources of T ₂ determined as described above, the destination node transmits a NACK, and the repeater overhears it. The repeater will perform retransmission. At this time, the resources used by the repeater to retransmit the data to the destination node may also be predetermined by the source node.

It may be assumed that channel conditions between the relay node and the destination node in the transmitting step of FIG. 12 (b) and the HARQ operation step of FIG. 12 (c) are the same. In other words, it is assumed that the channel between the relay and the destination node is a quasi-static channel. According to this assumption, the time resource T ₃ used for retransmission of the repeater may be determined as in Equations 27 and 28 below. Equation 27 shows a probability of occurrence of communication outage during HARQ retransmission during the HARQ operation step of FIG.

[Equation 27] out (3)

I (T _{2 +} T,)

<R _s / (T _{2 +} T ₃ )] ≤S ₃

2

According to Equation 27, R is the amount of information per unit time to be transmitted by the repeater in T ₃ , which is a time resource that the repeater will use for HARQ retransmission to the destination node, based on the occurrence of communication loss in the delivery step of FIG. Based on _s , the probability of occurrence of communication failure (P _{ou 3))} can be defined. ³ is serving as a reference value for the disruptions (outage) hwakreul for determining the presence or absence in the communication disruption _HAR Q retransmission step of Fig. _{12 (c).} By arranging Equation 27 with respect to T ₃ , Equation 28 can be derived.

[Equation 28] ^'

Based on Equation 28, in the HARQ retransmission step of FIG. 12 (c), a repeater transmits a signal to a destination node.

May be determined as in Equation 29 below. [Equation 29]

^ Δ ^ / (Γ ₂ + Γ ₃ ) <log ₂ [1-SR ^ ln (l-δ ₂ δ)] In the HARQ operation phase of FIG. 12 (c), the repeater is transferred in the transmission phase of FIG. 12 (b). An IR HARQ operation of transmitting only extra data from data transmitted to the destination node and performing decoding based on the total accumulated data at the destination node may be applied.

As described above, the source node may determine the optimal time resource (ie, T ₂ and Τ ₃ ) to be used for transmission and retransmission from the relay to the destination node. Here, determining the optimal values for Τ ₂ and Τ ₃ may be selecting a value maximizing the overall data rate R _tot . This may be expressed as Equation 30 below.

[Equation 30]

₊ ut (2) (1 一 d "(3)) As can be seen from Equation 30 above, as T ₂ and Τ ₃ increase, communication outage decreases, but damage occurs in the entire transmission. Therefore, by estimating the optimal τ ₂ and Τ ₃ by Equation 30 above, it is possible to allocate an optimized time resource that maximizes the average rate that can be obtained.

As described above, if it is difficult to estimate the exact information of the channel between the repeater and the destination node (i.e. when a type-2 repeater is used, such as a user-repeater), the destination from the source node through the repeater in a partial signaling manner. When delivering data to the node, scheduling information for the transmission from the repeater to the destination node may be determined in advance at the source node and inform the repeater. Accordingly, even in an open-loop environment in which accurate information about a channel between a repeater and a destination node is not given, it is possible to allocate an optimal time resource using a stochastic characteristic. In the above example, the time resource is allocated to the repeater by way of example, but the same principle described in the present invention may be applied to the case in which the frequency resource is allocated according to the probability of communication loss. As described above, the source node cannot schedule channel information between the relay node and the destination node in that the source node schedules resources and transmission rates to be used for transmission / retransmission from the relay to the destination node based on the probability of the communication failure. Can be effectively overcome. 13 is a diagram illustrating a wireless communication system including a base station apparatus, a repeater apparatus, and a terminal apparatus according to the present invention.

Referring to FIG. 13, the base station apparatus 1310 according to the present invention may include reception modules 1311, transmission modules 1312, a processor 1313, a memory 1314, and a plurality of antennas 1315. have. The plurality of antennas 1315 denote a base station apparatus that supports MIM0 transmission and reception. The receivers 1311 may receive various signals, data, and information on uplink from one or more of the terminal and the repeater. The transmission modules 1312 may transmit various signals, data, and information on downlinks to one or more of the terminal and the repeater. The processor 1313 may control the overall operation of the base station apparatus 1310. The base station apparatus 1310 according to an embodiment of the present invention may be configured to transmit data in a partial signal transmission scheme. The processor 1313 of the base station apparatus may be configured to bit concatenate one data for the terminal to the data for the repeater and encode the same to generate a first codeword. In addition, the processor 1313 may be configured to encode second data for the terminal to generate a second codeword. In addition, the processor 1313 may be configured to transmit a first codeword to the repeater and a second codeword to the terminal through transmission modes.

Here, the first and second codewords may be generated by a prior interference cancellation technique. The terminal may restore the data transmitted to the terminal using the first data and the second data. For example, the first data and the second data may correspond to portions in which information to be transmitted for the terminal is partitioned by the channel coded output by one channel coder. In addition, the first data for the terminal may be delivered to the terminal by the repeater. In this case, one or more of time resources and frequency resources used by the repeater to transmit the first data to the terminal may be variably determined by the base station. In addition, when the data rate per hour for the repeater and the data rate per hour ^ ₂ («, / ^ ₂ ) for the terminal are determined as shown in Equation 20, the base station determines that the transmission efficiency is improved. , And P ₂ can be determined.

The base station apparatus 1310 according to another embodiment of the present invention may be configured to predetermine scheduling information on transmission / retransmission of the repeater in transmitting data to the terminal through the repeater according to a partial signal transmission scheme. The processor 1313 of the base station apparatus may be configured to transmit a signal including the first data to be transmitted to the terminal by the repeater to the repeater through the transmission modules. In addition, the processor 1313 may be configured to transmit a signal including the second data to the terminal through a transmission mode. In addition, the processor 1313 may transmit the hybrid automatic retransmission request (HARQ) acknowledgment information for the first data transmitted to the terminal through the relay through the receiving modules. It may be configured to receive from the terminal. Here, when the HARQ acknowledgment information is a negative acknowledgment (NACK), the first data may be retransmitted from the repeater, not the base station, to the terminal. In addition, the first data from the repeater to the terminal. Scheduling information for transmission of data and scheduling information for retransmission of the first data may be previously designated by the base station.

Here, the scheduling information for transmitting / retransmitting the first data by the repeater may be determined based on the communication outage of the channel between the repeater and the terminal. The scheduling information may include one or more of time resource, frequency resource, and transmission rate used for transmission or retransmission of the first data. For example, the transmission rate of the repeater may be determined as shown in Equations 26 and 29, and the time resource for transmission / retransmission of the repeater may be predetermined by the base station such that the total transmission rate is maximized as shown in Equation 30. .

In addition, the HARQ acknowledgment information transmitted by the terminal with respect to transmission or retransmission of the first data may be overheared by the repeater, and thus, HARQ retransmission operation may be performed. In addition, the retransmission by the repeater may be performed in an incremental redundancy (IR) scheme. In addition, the terminal may restore the data for itself by using the first data transmitted through the repeater and the second data directly received from the base station. For example, the first data and the second data may correspond to portions of information in which information to be transmitted for the terminal is partitioned by the channel coded output by one channel coder.

In addition, the processor 1313 of the base station apparatus 1310 performs a function of processing the information received by the base station apparatus 1310, information to be transmitted to the outside, and the like. The memory 1314 stores the processed information and the like for a predetermined time. Can be stored and replaced by components such as buffers (not shown).

Referring to FIG. 13, a repeater device 1320 according to the present invention may include reception modules 1321, transmission modules 1322, a processor 1323, a memory 1324, and a plurality of antennas 1325. have. The plurality of antennas 1325 means a repeater device that supports MIM0 transmission and reception. Receive modules 1321 may include first and second receivers, and the first receive modules may receive various signals, data, and information on downlink from the base station, and the second receive module. To receive various signals, data and information on the uplink from the terminal. Can be received. The transmission modules 1322 may include first transmission modules and second transmission modules, and the first transmission modules may transmit various signals, data, and information on the uplink to the base station, and the second transmission modules may be connected to the terminal. It can transmit various signals, data and information on the downlink. The processor 1323 may control the overall operation of the repeater device 1320.

The repeater device 1320 according to an embodiment of the present invention may be configured to deliver data to the terminal according to a partial signal transmission scheme. The processor 1323 of the repeater device, from the base station through a first reception mode, generates a first codeword generated by bit concatenation of the first data for the terminal with the data for the repeater. Can be configured to receive. In addition, the processor 1323 may be configured to extract the first data from the first codeword. In addition, the processor 1323 may be configured to transmit the extracted first data to the terminal through a second transmission mode.

Here, at least one of a time resource and a frequency resource used by the repeater to transmit the first data to the terminal may be variably determined by the base station. In addition, a second codeword generated by encoding second data for the terminal by the base station may be transmitted from the base station to the terminal. The first and second codewords may be generated by a prior interference cancellation technique. In addition, the terminal may restore the data transmitted to itself by using the first data and the second data. For example, the first data and the second data may correspond to portions of information in which information to be transmitted for the terminal is partitioned by the channel coded output by one channel coder. Further, when the data rate ^C i (" ⁵ ^) per hour from the base station to the repeater and the data rate ^ (" C ² ) per hour from the base station to the terminal are determined as in Equation 20 above, the transmission efficiency And P ₂ can be determined by the base station so that this is improved.

The repeater device 1320 according to another embodiment of the present invention is configured to perform data transmission / retransmission to a terminal by using a resource scheduled by a base station when data is transmitted to the terminal through the partial signal transmission scheme. Can be. The processor 23 of the repeater apparatus may be configured to receive a signal from the base station via the first receiving modules, the signal comprising first data to be delivered to the terminal by the repeater. In addition, the processor 1323 may be configured to transmit the first data to the terminal through the second transmission mode. In addition, the processor 1323 may be configured to receive, from the terminal, hybrid automatic retransmission request (HARQ) acknowledgment information for the first data through the second receiving modules. In addition, when the HARQ acknowledgment information is a NACK, the processor 1323 may be configured to retransmit the first data to the terminal through the second transmission mode. Here, the scheduling information for transmission of the first data and the scheduling information for retransmission of the first data from the repeater to the terminal may be previously designated by the base station.

Here, the scheduling information for transmitting / retransmitting the first data by the repeater may be determined by the base station based on the probability of communication outage of the channel between the repeater and the terminal. The scheduling information may include one or more of time resources, frequency resources, and transmissions used for transmission or retransmission of the first data. For example, the transmission rate of the repeater may be determined as shown in Equations 26 and 29, and the time resource for the transmission / retransmission of the repeater may be predetermined by the base station so that the total transmission rate is maximized as shown in Equation 30. .

In addition, the processor 1323 of the repeater device 1320 performs a function of processing information received by the repeater device 1320, information to be transmitted to the outside, and the memory 1324 stores the calculated information and the like for a predetermined time. Can be stored and replaced with components such as buffers (not shown). Specific configurations of the base station apparatus and the repeater apparatus as described above may be configured such that the matters described in the above-described various embodiments of the present invention may be independently applied or two or more embodiments may be applied at the same time. Omit.

In addition, in the exemplary description of FIG. 13, the base station apparatus 1310 corresponds to the source node S in the above-described examples of the present invention, the repeater apparatus 1320 corresponds to the repeater R, and the terminal apparatus. 1330 may correspond to the destination node (D).

In addition, the description of the base station apparatus 1310 of FIG. 13 may be applied to a relay that controls a cell by itself. In addition, the description of the repeater device 1320 of FIG. 13 may be applied to a terminal device (ie, a user-relay device) that assists another terminal 1330 in a cooperative communication environment.

Embodiments of the present invention described above may be implemented through various means. For example, embodiments of the present invention may be implemented by hardware, firmware, software, or a combination thereof.

In the case of a hardware implementation, a method according to embodiments of the present invention may include one or more ASICs (App 1 i Cat Ion Specific Integrated Circuits), DSPs (Digital Signal Processors), DSPDs (Digital Signal Processing Devices), PLDs ( Programmable Logic Devices (FPMS), Field Programmable Gate Arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, and the like.

In the case of implementation by firmware or software, the method according to the embodiments of the present invention may be implemented in the form of modules, procedures or functions for performing the functions or operations described above. The software code may be stored in a memory unit and driven by a processor. The memory unit may be located inside or outside the processor, and may exchange data with the processor by various known means.

The detailed description of the preferred embodiments of the invention disclosed as described above is provided to enable those skilled in the art to implement and practice the invention. Although the above has been described with reference to preferred embodiments of the present invention, those skilled in the art will understand that various modifications and changes can be made without departing from the scope of the present invention. For example, those skilled in the art can use each of the configurations described in the above-described embodiments in combination with each other. Thus The invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

The invention can be embodied in other specific forms without departing from the spirit and essential features of the invention. Accordingly, the above detailed description should not be interpreted as limiting in all aspects and should be considered as illustrative. The scope of the invention should be determined by reasonable interpretation of the appended claims, and all changes within the equivalent scope of the invention are included in the scope of the invention. The present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein. In addition, the claims may be incorporated into claims that do not have an explicit citation relationship in the claims, or may be incorporated into new claims by amendment after filing.

Industrial Applicability

Embodiments of the present invention as described above may be applied to various mobile communication systems.

Claims

[Range of request]

[Claim 1]

As a method for transmitting data at the base station,

Generating a first codeword by bit concatenating the first data for the terminal to the data for the repeater;

Generating a second codeword by encoding second data for the terminal; And transmitting the first codeword to the repeater and transmitting the second codeword to the terminal.

[Claim 2]

The method of claim 1,

The first data for the terminal is transmitted to the terminal by the repeater.

[Claim 3]

The method of claim 2,

At least one of a time resource and a frequency resource used by the repeater to transmit the first data to the terminal is variably determined by the base station.

[Claim 4]

3. The method according to claim 2, wherein the data rate per hour for the repeater is

The data rate per hour for the terminal ^ ² (α, ^, Ρ ² ) is

And '

t ⁽¹⁾ is the time taken in the transmission step,

t ⁽²⁾ is the time required for the transfer of the first data in the repeater, ^ Is a ratio occupied by the first data in the first codeword,

Pi and P ₂ are the transmit powers for the first and second codewords, respectively,

^ 1 is the signal-to-interference ratio for the channel from the base station to the repeater,

^ 2 is the signal-to-interference ratio for the channel from the base station to the terminal, where ^, P _x and P ₂ are determined by the base station.

[Claim 5]

The method of claim 1,

The repeater is a first terminal, and the terminal is a second terminal.

[Claim 6]

The method of claim 1,

The first and second codewords are generated by a prior interference cancellation scheme.

[Claim 7]

The method of claim 1,

The first data and the second data correspond to each of a part of the information to be transmitted for the terminal partitioned the channel-coded output by one channel coder in the base station.

[Claim 8]

As a method of transmitting data from a repeater,

Receiving from the base station a first codeword generated by bit concatenation at the base station with the first data for the terminal to the data for the repeater;

Extracting the first data from the first codeword; And

Transmitting the extracted first data to the terminal.

[Claim 9]

The method of claim 8,

At least one of a time resource and a frequency resource used by the repeater to transmit the first data to the terminal is variably changed by the base station. The method of data transmission determined.

[Claim 10]

The method of claim 8,

And a second codeword generated by encoding the second data for the terminal by the base station is transmitted from the base station to the terminal.

[Claim 111]

The method of claim 10 wherein said data per tone transmissions to the repeater from the base ^station)

(l-) log (l + ^)

I ^"| '

Hourly data transmission for the end of the base station

t ⁽¹⁾ is the time taken in the transmission step,

t ⁽²⁾ is the time required for the transmission of the first data in the repeater,

oc is a ratio occupied by the first data in the first codeword,

^ And P ₂ are transmit powers for the first and second codewords, respectively,

^ 2 is the signal-to-interference ratio for the channel from the base station to the terminal, where ", Pi and P ₂ are determined by the base station."

[Claim 12]

The method of claim 10,

Wherein the first and second codewords are generated by a prior interference cancellation technique.

[Claim 13]

The method of claim 8,

And the repeater is a first terminal, and the terminal is a second terminal.

[Claim 14]

The method of claim 1,

[Claim 15]

As a base station for transmitting data,

A transmission module for transmitting a signal to at least one relay and a terminal proof;

Receiving modules receiving a signal from at least one of the repeater and the terminal; And

A processor connected to the receiving module and the transmission modules and controlling the operation of the base station;

The processor is,

Generate a second codeword by encoding second data for the terminal;

And transmit the first codeword to the repeater and the second codeword to the terminal through the transmission modes. [Claim 16]

As a repeater for transmitting data,

First receiving modules receiving a signal from a base station;

First transmission modules for transmitting a signal to the base station;

Second receiving modules for receiving a signal from the terminal;

Second transmission modules for transmitting a signal to the terminal; And

A processor connected to the first and second reception modules and the first and second transmission modules and controlling the operation of the repeater;

The processor is,

Receiving, from the base station, a first codeword generated by bit-concatenation at the base station with the data for the terminal and encoding the first data for the terminal together with the first receiving modules; Extract the first data from the first codeword;

And transmit the extracted first data to the terminal through the second transmission modes.