KR20100052387A - Method for transmitting data from base station to relay in a system supportin legacy system - Google Patents

Abstract

PURPOSE: A method for transmitting data from base station to relay in a system supporting legacy system is provided to prevent SI(Self Interference) phenomenon with a support of legacy terminal in case of relay is introduces in a 3GPP(3rd Generation Partnership Project) LTE-A(Long Term Evolution-Advanced) system. CONSTITUTION: A base station generates a sub frame for data transmission about relay. The base station transmits the sub frame to the relay. The sub frame comprises OFDM symbol of predetermined number. The relay uses OFDM symbol for transmission of a control channel and a reference signal. The base station uses OFDM except the OFDM symbol for transmission of the control channel and the reference signal among the symbols in the data transmission about the relay.

Description

METHOD FOR TRANSMITTING DATA FROM BASE STATION TO RELAY IN A SYSTEM SUPPORTIN LEGACY SYSTEM}

The present invention relates to a mobile communication technology, and relates to a method for a base station to transmit data to a relay in a system supporting a legacy system.

Relay, interference coordination, or multicell transmission to improve traditional metrics such as sector throughput or cell throughput in next-generation mobile communication systems New technologies are being considered.

In designing a system by introducing a new technology as described above, there are different things that the system should consider depending on whether or not an existing system exists. If no existing system exists, the system is designed using an optimized approach. However, if the existing system exists, the system is designed so as not to affect the performance of the existing system.

Among the above technologies, the relay may be used for the purpose of eliminating the shadow area in the cell in the next generation mobile communication system, and may be used for the purpose of effectively extending the cell coverage and improving the performance by installing the relay in the cell boundary region.

1 is a configuration diagram of a relay system. As illustrated in FIG. 1, the relay system performs communication through a relay in communication between an evolved Node B (eNB) and a user equipment (UE). Since the relay uses a wireless backhaul rather than a wired backhaul link, a relay does not need to add a new eNB or install a wired backhaul.

The relay is supported by an IEEE 802.16e / 16m terminal and the like, and may have a base station function. The relay is an active repeater that includes network entry and mobility, RRM, and security functions of a PMP based relay. The relay decodes the signal received from the transmitter, re-encodes it, and passes the signal to the receiver, thereby eliminating noise and using a higher data rate coding to obtain a high performance digital amplifier. It acts as a digital amplifier. On the other hand, a relay has a disadvantage in that a delay may be generated during decoding and encoding. In addition, the relay should consider the backward compatibility problem of the PMP mode.

Relay types are classified as follows according to mobility.

First, a fixed relay is permanently fixed and used to increase shadow area or cell coverage. Simple repeater functions are also possible. Nomadic relays are relays that can be temporarily installed or moved randomly within a building when the user suddenly increases. Mobile relays are relays that can be mounted on public transport such as buses and subways.

2 illustrates a frame structure for supporting a relay in a conventional broadband wireless access system. A relay DL zone and a relay UL zone are set in the BS frame structure and the RS frame structure of the relay. Data transmitted from the base station to the relay is assigned to the downlink of the BS frame structure of the base station in the form of a burst, and data transmitted from the relay to the mobile terminal or the adjacent relay is downlink of the RS frame structure of the relay. Assign to link area.

In case of data to be transmitted by the mobile terminal or the neighboring relay to the base station, the mobile station or the adjacent relay transmits data from the uplink region of the relay to the allocated region for each terminal, and the relay includes the data in the region allocated to the relay in the uplink.

Therefore, supporting relay on a structure is simply supported. If a method for supporting a data transaction procedure of a terminal is additionally set through a communication protocol between a base station and a relay, the relay may send a packet for a specific terminal. You can do a packet relay.

On the other hand, in the 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) system, a zone concept such as IEEE 802.16 is not defined in Time Division Duplexing (TDD) or Frequency Division Duplexing (FDD). That is, the UE is unconditionally watching the downlink stream, and if it is not changed to a specific format, there is freedom to read all the downlink subframes.

On the other hand, in the case of 3GPP LTE-Advanced (hereinafter, referred to as LTE-A), a relay must be supported and a terminal supported by 3GPP LTE can perform communication by accessing an eNB (evolved Node B) through the corresponding relay. It should be possible. That is, in the 3GPP LTE-A system, the relay must satisfy backward compatibility with a terminal supported by the 3GPP LTE system. In the LTE-A system, an independent eNB is used as a relay and a macro-cell eNB and a terminal communicate with each other, not a structure with a relay in between. Instead, a macro-cell eNB wirelessly provides a backbone connection to the relay. , The eNB of the relay corresponds to an independent cell.

In the following description, the term "legacy system" refers to a system that is already defined, and "legacy mobile station" refers to a mobile terminal supported by a legacy system. . Therefore, from the standpoint of the 3GPP LTE-A system, the 3GPP LTE system corresponds to a legacy system.

Meanwhile, the relay includes an inband relay and an outband relay according to the frequency band of the wireless backhaul communicating with the eNB. The case where the frequency band used for the link between the eNB and the relay is the same as the frequency band used for the link between the relay and the mobile terminal is called an in-band relay, and the other case is called an out-band relay. The use of an outband relay decreases the frequency usage efficiency because additional frequency resources are required, but it can prevent a self interference (SI) phenomenon, which is one of the problems that occurs when the relay is applied.

SI refers to interference caused by a signal of a transmitting antenna when a signal is transmitted and received in the same band at the same time by a transmitting antenna and a receiving antenna of a relay. In-band relay does not waste frequency resources, but requires a separate technology to prevent the SI phenomenon.

Therefore, in the 3GPP LTE-A system, when introducing a relay, the system should support the legacy terminal and at the same time prevent the SI phenomenon.

In the present invention, the present invention provides a method for a base station to transmit data to a relay in a system supporting a legacy system.

In a system supporting a legacy system according to an aspect of the present invention for solving the above problems, a method for transmitting data to a relay by a base station includes a subframe for transmitting the data to the relay by the base station. generating a subframe; And transmitting the generated subframe to the relay, wherein the subframe includes a predetermined number of OFDM symbols, and used by the base station to transmit data to the relay among the predetermined number of OFDM symbols. The OFDM symbol excludes an OFDM symbol overlapping with an OFDM symbol used by the relay to transmit a control channel and a reference signal to a legacy user equipment supported by the legacy system.

Preferably, the subframe includes 14 OFDM symbols, and the base station is used to transmit data to the relay when assigning indexes from 0 to 13 sequentially on the time axis to each of the 14 OFDM symbols. The OFDM symbol may correspond to any one of cases 1 to 6 of Table 1 below.

case  OFDM symbol index for the base station to transmit data to the relay One  2, 3, 5, 6, 9, 10, 12, 13 2  3, 5, 6, 9, 10, 12, 13 3  2, 3, 12, 13 4  3, 12, 13 5  2, 3, 9, 10, 12, 13 6  3, 9, 10, 12, 13

Preferably, the subframe is designated as an MBSFN subframe, and one subframe includes 14 OFDM symbols, and when the 14 OFDM symbols are sequentially indexed from 0 to 13 on the time axis, The OFDM symbol used by the base station to transmit data to the relay may correspond to any one of cases 1 to 6 of Table 2 below.

case  OFDM symbol index for the base station to transmit data to the relay One  2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 2  3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 3  2, 3, 4, 11, 12, 13 4  3, 4, 11, 12, 13 5  2, 3, 4, 7, 8, 9, 10, 11, 12, 13 6  3, 4, 7, 8, 9, 10, 11, 12, 13

Advantageously, said subframe comprises 12 OFDM symbols and is used by said base station to transmit data to said relay when assigning an index from 0 to 11 sequentially on the time axis to each of said 12 OFDM symbols. The OFDM symbol may correspond to any one of cases 1 to 6 of Table 3 below.

case  OFDM symbol index for the base station to transmit data to the relay One  2, 4, 5, 8, 10, 11 2  4, 5, 8, 10, 11 3  2, 10, 11 4  10, 11 5  2, 8, 10, 11 6  8, 10, 11

Advantageously, said one subframe is designated an MBSFN subframe, and said one subframe includes 12 OFDM symbols, with time sequentially indexed from 0 to 11 on a time axis in each of said 12 OFDM symbols. When granting, OFDM symbol used by the base station to transmit data to the relay may correspond to any one of cases 1 to 6 of Table 4 below.

case  OFDM symbol index for the base station to transmit data to the relay One  2, 3, 4, 5, 6, 7, 8, 9, 10, 11 2  3, 4, 5, 6, 7, 8, 9, 10, 11 3  2, 3, 10, 11 4  3, 10, 11 5  2, 3, 4, 7, 8, 9, 10, 11 6  3, 4, 7, 8, 9, 10, 11

Advantageously, said one subframe includes 14 OFDM symbols, and when each 14 OFDM symbols are sequentially indexed from 0 to 13 on the time axis, the base station transmits data to the relay. The OFDM symbol used for this may correspond to any one of cases 1 to 9 of Table 5 below.

case  OFDM symbol index for the base station to transmit data to the relay One  1, 2, 3, 5, 6, 8, 9, 10, 12, 13 2  2, 3, 5, 6, 8, 9, 10, 12, 13 3  3, 5, 6, 8, 9, 10, 12, 13 4  1, 2, 3, 12, 13 5  2, 3, 12, 13 6  3, 12, 13 7  1, 2, 3, 8, 9, 10, 12, 13 8  2, 3, 8, 9, 10, 12, 13 9  3, 8, 9, 10, 12, 13

Advantageously, said one subframe is designated an MBSFN subframe, and said one subframe includes 14 OFDM symbols, and each of said 14 OFDM symbols is sequentially indexed from 0 to 13 on a time axis. In this case, the OFDM symbol used by the base station to transmit data to the relay may correspond to any one of cases 1 to 9 of Table 6 below.

case  OFDM symbol index for the base station to transmit data to the relay One  1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 2  2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 3  3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 4  1, 2, 3, 4, 11, 12, 13 5  2, 3, 4, 11, 12, 13 6  3, 4, 11, 12, 13 7  1, 2, 3, 4, 7, 8, 9, 10, 11, 12, 13 8  2, 3, 4, 7, 8, 9, 10, 11, 12, 13 9  3, 4, 7, 8, 9, 10, 11, 12, 13

Advantageously, said one subframe includes 12 OFDM symbols, and when each of said 12 OFDM symbols is sequentially indexed from 0 to 11 on a time axis, the base station transmits data to said relay. OFDM symbol used for this may correspond to any one of cases 1 to 9 of Table 7 below.

case  OFDM symbol index for the base station to transmit data to the relay One  1, 2, 4, 5, 7, 8, 10, 11 2  2, 4, 5, 7, 8, 10, 11 3  4, 5, 7, 8, 10, 11 4  1, 2, 10, 11 5  2, 10, 11 6  10, 11 7  1, 2, 7, 8, 10, 11 8  2, 7, 8, 10, 11 9  7, 8, 10, 11

Advantageously, said one subframe is designated an MBSFN subframe, and said one subframe includes 12 OFDM symbols, and each of the 12 OFDM symbols is sequentially indexed from 0 to 11 on a time axis. In doing so, the OFDM symbol used by the base station to transmit data to the relay may correspond to any one of cases 1 to 9 of Table 8 below.

case  OFDM symbol index for the base station to transmit data to the relay One  1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 2  2, 3, 4, 5, 6, 7, 8, 9, 10, 11 3  3, 4, 5, 6, 7, 8, 9, 10, 11 4  1, 2, 3, 10, 11 5  2, 3, 10, 11 6  3, 10, 11 7  1, 2, 3, 6, 7, 8, 9, 10, 11 8  2, 3, 6, 7, 8, 9, 10, 11 9  3, 6, 7, 8, 9, 10, 11

Preferably, the information on the time and frequency resource location where the data is located on the subframe may be transmitted through a physical downlink control channel (PDCCH).

Preferably, a portion of the OFDM symbol used by the base station to transmit the data to the relay is allocated to a control channel for transmitting information on time and frequency resource location where the data is located on the subframe. Can be.

Advantageously, the method may further comprise transmitting, at a predetermined period, information from the base station to the relay regarding the time and frequency resource location at which the data is located on the subframe.

Preferably, the control channel may include a Physical Control Format Indicator CHannel (PCFICH), a Physical Downlink Control CHannel (PDCCH), and a Physical Hybrid ARQ Indicator CHannel (PHICH).

Preferably, the control channel may further include at least one of a Primary Synchronization CHannel (PSCH), a Secondary Synchronization CHannel (SSCH), and a Physical Broadcast CHannel (PBCH).

According to the embodiments of the present invention as described above, the relay can efficiently receive data from the base station while supporting the legacy system. In addition, communication with the relay and the base station can be set smoothly.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following detailed description, together with the accompanying drawings, is intended to illustrate exemplary embodiments of the invention and is not intended to represent the only embodiments in which the invention may be practiced. The following detailed description includes specific details in order to provide a thorough understanding of the present invention. However, one of ordinary skill in the art appreciates that the present invention may be practiced without these specific details.

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

If the new system supports relays, the relays should not affect the legacy system, and the relay should not prevent the legacy system from working properly. For example, if an LTE-Advanced (LTE-A) system supports relay, the relay should not affect the existing LTE system, and the relay should not prevent the existing LTE system from working properly. . Therefore, hereinafter, the relay communication structure supporting the LTE system will be described.

FIG. 3 illustrates a radio frequency division duplexing (FDD) frame structure of a 3GPP LTE system in a normal cyclic prefix (normal CP) case. In FIG. 3, the FDD frame is composed of 10 subframes from 0th to 9th. In addition, each subframe consists of a total of 14 Orthogonal Frequency Division Multiplexing (OFDM) symbols in the case of the standard cyclic prefix.

In the FDD frame structure, the 0th and 5th subframes (denoted as Subframe 0 and Subframe 5 in FIG. 3, respectively) are a first synchronization channel (PSCH) and a second synchronization channel for a synchronization signal. (Secondary Synchronization CHannel; SSCH) is transmitted. In addition, the 0th subframe has a structure in which a physical broadcast channel (PBCH) is transmitted in addition to a synchronization signal. Accordingly, in the system, the 0 th subframe is configured to transmit the SSCH, PSCH, and PBCH, and the 5 th subframe is configured to transmit the SSCH and PSCH. In particular, in the 0th and 5th subframes, the 5th OFDM symbol is an OFDM symbol for transmitting the SSCH, the 6th OFDM symbol is an OFDM symbol for transmitting the PSCH, and 7th to 10th in the 0th subframe. An OFDM symbol is an OFDM symbol for transmitting a PBCH.

Meanwhile, in the case of a normal cyclic prefix (normal CP), in a radio frequency division duplexing (FDD) frame structure of a 3GPP LTE system, each subframe is an extended cyclic prefix. A total of 12 Orthogonal Frequency Division Multiplexing (OFDM) symbols are formed. In the FDD frame structure, subframes 0 and 5 are configured to transmit a primary synchronization channel (PSCH) and a second synchronization channel (SSCH) for a synchronization signal. . In addition, the 0th subframe has a structure in which a physical broadcast channel (PBCH) is transmitted in addition to a synchronization signal. Accordingly, in the system, the 0 th subframe is configured to transmit the SSCH, PSCH, and PBCH, and the fifth subframe is configured to transmit the SSCH and PSCH. In particular, in the 0th and 5th subframes, the 4th OFDM symbol is an OFDM symbol for transmitting the SSCH, the 5th OFDM symbol is an OFDM symbol for transmitting the PSCH, and 6th to 9th OFDM in the 0th subframe. The symbol is an OFDM symbol for transmitting a PBCH.

Meanwhile, in 3GPP LTE, a common reference signal is used to measure a channel while serving as a reference symbol for traffic transmitted in downlink. 4 illustrates a structure of an OFDM symbol in which a common reference signal is transmitted in one subframe when the standard cyclic prefix is used. In the case of a normal cyclic prefix (normal CP) as shown in FIG. 4, one subframe includes a total of 14 Orthogonal Frequency Division Multiplexing (OFDM) symbols from 0th to 13th and common reference. The signal is present in the 0th, 1st, 4th, 7th, 8th, and 11th OFDM symbols of each subframe.

In order for the system to support the legacy mobile terminal, the structure of the above-described subframe should be equally applied to the relay. After synchronizing, the legacy mobile terminal can check the cell ID detected by the common reference signal (common RS) transmitted from the system, and also the synchronization channel or common reference for channel measurement. The signal can always be measured.

Therefore, in order for the relay to operate correctly in the system described above, the relay must transmit the channel and the reference signal described above without interruption.

In addition, each subframe includes a Physical Control Format Indicator CHannel (PCFICH), a Physical Downlink Control CHannel (PDCCH), and a Physical Hybrid ARQ Indicator CHannel (PHICH) which are downlink physical channels. It may occupy a third Orthogonal Frequency Division Multiplexing (OFDM).

Hereinafter, a combination of OFDM symbols on a subframe that the relay can use to communicate with the eNB while the relay supports the legacy mobile terminal will be described based on the above description.

FIG. 5 shows the structure of an OFDM symbol used by a relay in one subframe in the case of standard cyclic prefix. In FIG. 5, type 1 always indicates an OFDM symbol in which a reference signal or a control channel is located for a legacy mobile terminal regardless of whether a subframe is designated as an MBSFN subframe, and the 0th and 1st OFDM symbols of the subframe are types. Corresponds to 1. Type 2 represents an OFDM symbol for transmitting a reference signal for a legacy terminal when the subframe is not designated as an MBSFN subframe, and the 4th, 7th, 8th, and 11th OFDM symbols correspond to type 2. Type 4 represents an OFDM symbol that can be used for transmission of a PBCH for a legacy terminal, and the 0th and 9th OFDM symbols correspond to type 4. Type 3 represents the remaining OFDM symbols except Type 1, Type 2, and Type 4, and the 2, 3, 5, 6, 12, and 13th OFDM symbols correspond to Type 3.

In FIG. 5, the OFDM symbols indicated by Type 1 and Type 2 mean OFDM symbols that the relay cannot use to support legacy mobile terminals, and the OFDDM symbols indicated by Type 3 and Type 4 may be used for communication between the eNB and the relay. Means a symbol that can be.

If the relay provides a service only to the mobile terminal, the relay may use all the OFDM symbols shown in FIG. 4 for downlink transmission. Therefore, data can be transmitted to the terminal while maintaining the same frame structure as in the LTE system. However, the relay can provide a smooth service to the mobile terminal only by receiving data from the eNB or transmitting data to the eNB. That is, information transmitted from the eNB should be delivered to the mobile terminal or information transmitted from the mobile terminal to the relay should be delivered to the eNB.

Unless the relay is capable of transmitting and receiving signals in the same frequency band at the same time, only one operation is possible in the same frequency band. The relay may transmit all control channels expected by the mobile station in a specific subframe and receive data from the base station only in the remaining areas.

For an OFDM symbol occupied by the PCFICH, PHICH, and PDCCH (for example, 0 th to 3 th OFDM symbols) and an OFDM symbol in which a common reference signal is transmitted, a relay broadcasts a signal regardless of whether data exists in the OFDM symbol. broadcast). When supporting the legacy mobile terminal, since the relay receives a signal from the base station through an OFDM symbol in which the control channel and the common reference signal do not exist, the relay cannot transmit a signal to the legacy mobile terminal.

Accordingly, a subframe should not have a physical downlink shared channel (PDSCH) delivered to a legacy mobile terminal, and if a 3GPP LTE-A system supports a new terminal, a subcarrier transmitted with a control channel or a common reference signal The subcarriers that are not used among these may be used for 3GPP LTE-A terminal information transmission. In addition, information allocated to the 3GPP LTE-A terminal may also be delivered to the PDCCH.

Example  One

In consideration of the above considerations, in the case of four or more transmit antennas and a standard cyclic prefix, a combination of OFDM symbols on a subframe that can be used between the relay and the eNB is shown in Table 9 below.

case Channel transfer situation OFDM symbol index One PDCCH Length≤ 2 OFDMs, PSCH (x), SSCH (x), PBCH (x) 2, 3, 5, 6, 9, 10, 12, 13 2 PDCCH length ≤ 3 OFDMs, PSCH (x), SSCH (x), PBCH (x) 3, 5, 6, 9, 10, 12, 13 3 PDCCH Length≤ 2 OFDMs, PSCH (0), SSCH (0), PBCH (0) 2, 3, 12, 13 4 PDCCH length ≤ 3 OFDMs, PSCH (0), SSCH (0), PBCH (0) 3, 12, 13 5 PDCCH length≤ 2 OFDMs, PSCH (0), SSCH (0), PBCH (x) 2, 3, 9, 10, 12, 13 6 PDCCH length≤ 3 OFDMs, PSCH (0), SSCH (0), PBCH (x) 3, 9, 10, 12, 13

In Table 9, the OFDM symbol index indicates the index of the OFDM symbol on the subframe that can be used between the relay and the eNB, and each number indicates the number of OFDM symbols on the subframe. In Table 9, the OFDM symbol of each subframe is 14 OFDM symbols are included in total from 0th to 13th.

In Table 9, the length of the PDCCH is represented by an OFDM symbol occupied by the PDCCH on one subframe, and is less than two OFDM symbols or less than three OFDM symbols. Also, PSCH (x), SSCH (x), and PBCH (x) indicate a case in which PSCH, SSCH, and PBCH are not transmitted because the subframe does not correspond to the 0th and 5th subframes on the FDD frame. 0), SSCH (0) and PBCH (x) indicate a case in which the subframe corresponds to the fifth subframe on the FDD frame and transmits PSCH and SSCH but does not transmit PBCH, and PSCH (0) and SSCH ( 0), PBCH (0) indicates a case in which a subframe transmits a PSCH, an SSCH, and a PBCH corresponding to a 0 th subframe on an FDD frame.

In Table 9, Cases 1 and 2 represent remaining subframes except for the 0th and 5th frames on the FDD frame, Cases 3 and 4 represent the 0th subframe, and Cases 5 and 6 represent the fifth subframe. Therefore, when the OFDM symbol is used according to each case shown in Table 9 in the communication between the relay and the eNB, communication between the relay and the eNB is possible while supporting the legacy mobile terminal.

Meanwhile, when one subframe is designated as a multicast broadcast single frequency network (MBSFN) subframe, the legacy mobile terminal recognizes that the corresponding subframe includes a unicast part and a multicast part. However, while the legacy mobile terminal initially performs a cell search process, the information of the MBSFN cannot be obtained from the relay signal. Therefore, the use of the OFDM symbol should be considered.

Since the subframe is designated as the MBSFN subframe, the fourth, seventh, eighth and eleventh OFDM symbols used for transmitting the common reference signal in the first embodiment can be used for communication between the relay and the eNB. Therefore, when the subframe is designated as MBSFN, when there are four or more transmit antennas and the standard cyclic prefix, the combination of OFDM symbols on the subframe that can be used between the relay and the eNB is shown in Table 10 below. In Table 10 below, type 2 OFDM symbols, which were not available in Table 9, may be additionally used for communication between the eNB and the relay.

case Channel transfer situation OFDM symbol index One PDCCH length≤2 OFDMs, PSCH (x), SSCH (x), PBCH (x) 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 2 PDCCH length ≤ 3 OFDMs, PSCH (x), SSCH (x), PBCH (x) 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 3 PDCCH Length≤ 2 OFDMs, PSCH (0), SSCH (0), PBCH (0) 2, 3, 4, 11, 12, 13 4 PDCCH length ≤ 3 OFDMs, PSCH (0), SSCH (0), PBCH (0) 3, 4, 11, 12, 13 5 PDCCH length≤ 2 OFDMs, PSCH (0), SSCH (0), PBCH (x) 2, 3, 4, 7, 8, 9, 10, 11, 12, 13 6 PDCCH length≤ 3 OFDMs, PSCH (0), SSCH (0), PBCH (x) 3, 4, 7, 8, 9, 10,11, 12, 13

In Table 10, the length of the PDCCH is represented by an OFDM symbol occupied by the PDCCH on one subframe, and is less than two OFDM symbols or less than three OFDM symbols. Also, PSCH (x), SSCH (x), and PBCH (x) indicate a case in which PSCH, SSCH, and PBCH are not transmitted because the subframe does not correspond to the 0th and 5th subframes on the FDD frame. 0), SSCH (0) and PBCH (x) indicate a case in which the subframe corresponds to the fifth subframe on the FDD frame and transmits PSCH and SSCH but does not transmit PBCH, and PSCH (0) and SSCH ( 0), PBCH (0) indicates a case in which a subframe transmits a PSCH, an SSCH, and a PBCH corresponding to a 0 th subframe on an FDD frame.

In Table 10, Cases 1 and 2 represent remaining subframes except for the 0th and 5th frames on the FDD frame, Cases 3 and 4 represent the 0th subframe, and Cases 5 and 6 represent the fifth subframe. Therefore, when the OFDM symbol is used according to each case shown in Table 10 in the communication between the relay and the eNB, communication between the relay and the eNB is possible while supporting the legacy mobile terminal.

However, when configured as shown in Table 10, the operation of the mobile terminal may have the following unexpected results. For example, a legacy mobile terminal performing cell search searches for PSCH / SSCH and decodes the PBCH with a reference symbol structure corresponding to the cell ID. Since the location of the MBSFN subframe may not be known until all system information is received, the legacy mobile terminal may use the common reference signals of all subframes. Therefore, in consideration of such a case, it is preferable to use the common reference signal as a structure for transmitting a relay. That is, even if the subframe is designated as the MBSFN subframe, the subframe structure shown in Table 9 may be used instead of Table 10 in order to prevent a malfunction of the mobile terminal by the common reference signal.

Example  2

FIG. 6 shows a structure of an OFDM symbol used by a relay in one subframe in the case of an extended cyclic prefix (extended CP). In the case of a normal cyclic prefix (normal CP) as shown in FIG. 6, one subframe consists of a total of 12 OFDM symbols from 0th to 12th and a common reference signal of each subframe. It exists in 0th, 1st, 3rd, 6th, 7th, and 9th OFDM symbols. Compared to the standard cyclic prefix, in the case of the extended cyclic prefix, the number of usable OFDM symbols in one subframe is reduced by two.

In addition, in the FDD frame structure, the 0th and 5th subframes (represented as Subframe 0 and Subframe 5 in FIG. 3, respectively) may include a primary synchronization channel (PSCH) and a second synchronization channel for a synchronization siganl. A channel (Secondary Synchronization CHannel (SSCH)) is transmitted. In addition, the 0th subframe has a structure in which a physical broadcast channel (PBCH) is transmitted in addition to a synchronization signal. Accordingly, in the system, the 0 th subframe is configured to transmit the SSCH, PSCH, and PBCH, and the 5 th subframe is configured to transmit the SSCH and PSCH. In particular, in the 0th and 5th subframes, the 4th OFDM symbol is an OFDM symbol for transmitting the SSCH, the 5th OFDM symbol is an OFDM symbol for transmitting the PSCH, and 6th to 9th OFDM in the 0th subframe. The symbol is an OFDM symbol for transmitting a PBCH.

In consideration of the above, in the case of four or more transmit antennas and a standard cyclic prefix, a combination of OFDM symbols on a subframe that can be used between the relay and the eNB is shown in Table 11 below.

case Channel transfer situation OFDM symbol index One PDCCH length≤2 OFDMs, PSCH (x), SSCH (x), PBCH (x) 2, 4, 5, 8,10, 11 2 PDCCH length ≤ 3 OFDMs, PSCH (x), SSCH (x), PBCH (x) 4, 5, 8,10, 11 3 PDCCH Length≤ 2 OFDMs, PSCH (0), SSCH (0), PBCH (0) 2, 10, 11 4 PDCCH length ≤ 3 OFDMs, PSCH (0), SSCH (0), PBCH (0) 10, 11 5 PDCCH length≤ 2 OFDMs, PSCH (0), SSCH (0), PBCH (x) 2, 8, 10, 11 6 PDCCH length≤ 3 OFDMs, PSCH (0), SSCH (0), PBCH (x) 8, 10, 11

In addition, in Table 11, the length of the PDCCH is represented by an OFDM symbol occupied by the PDCCH on one subframe, and is less than two OFDM symbols or less than three OFDM symbols. Also, PSCH (x), SSCH (x), and PBCH (x) indicate a case in which PSCH, SSCH, and PBCH are not transmitted because the subframe does not correspond to the 0th and 5th subframes on the FDD frame. 0), SSCH (0) and PBCH (x) indicate a case in which the subframe corresponds to the fifth subframe on the FDD frame and transmits PSCH and SSCH but does not transmit PBCH, and PSCH (0) and SSCH ( 0), PBCH (0) indicates a case in which a subframe transmits a PSCH, an SSCH, and a PBCH corresponding to a 0 th subframe on an FDD frame.

In Table 11, Cases 1 and 2 represent remaining subframes except for the 0th and 5th frames on the FDD frame, Cases 3 and 4 represent the 0th subframe, and Cases 5 and 6 represent the fifth subframe. Therefore, when the OFDM symbol is used according to each case shown in Table 11 in the communication between the relay and the eNB, communication between the relay and the eNB is possible while supporting the legacy mobile terminal.

On the other hand, when the subframe is designated as MBSFN, when there are four or more transmit antennas and the extended cyclic prefix, the combination of OFDM symbols on the subframe that can be used between the relay and the eNB is shown in Table 12 below.

case Channel transfer situation OFDM symbol index One PDCCH length≤2 OFDMs, PSCH (x), SSCH (x), PBCH (x) 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 2 PDCCH length ≤ 3 OFDMs, PSCH (x), SSCH (x), PBCH (x) 3, 4, 5, 6, 7, 8, 9, 10, 11 3 PDCCH Length≤ 2 OFDMs, PSCH (0), SSCH (0), PBCH (0) 2, 3, 10, 11 4 PDCCH length ≤ 3 OFDMs, PSCH (0), SSCH (0), PBCH (0) 3, 10, 11 5 PDCCH length≤ 2 OFDMs, PSCH (0), SSCH (0), PBCH (x) 2, 3, 4, 7, 8, 9, 10, 11 6 PDCCH length≤ 3 OFDMs, PSCH (0), SSCH (0), PBCH (x) 3, 4, 7, 8, 9, 10, 11

In addition, in Table 12, the length of the PDCCH is represented by an OFDM symbol occupied by the PDCCH in one subframe, and is less than two OFDM symbols or less than three OFDM symbols. Also, PSCH (x), SSCH (x), and PBCH (x) indicate a case in which PSCH, SSCH, and PBCH are not transmitted because the subframe does not correspond to the 0th and 5th subframes on the FDD frame. 0), SSCH (0) and PBCH (x) indicate a case in which the subframe corresponds to the fifth subframe on the FDD frame and transmits PSCH and SSCH but does not transmit PBCH, and PSCH (0) and SSCH ( 0), PBCH (0) indicates a case in which a subframe transmits a PSCH, an SSCH, and a PBCH corresponding to a 0 th subframe on an FDD frame.

In Table 12, Cases 1 and 2 represent remaining subframes except for the 0th and 5th frames on the FDD frame, Cases 3 and 4 represent the 0th subframe, and Cases 5 and 6 represent the fifth subframe. Therefore, when the OFDM symbol is used according to each case shown in Table 12 in the communication between the relay and the eNB, communication between the relay and the eNB is possible while supporting the legacy mobile terminal.

On the other hand, as described in the first embodiment, in order to prevent the mobile terminal from malfunctioning by the common reference signal, even if the subframe is designated as the MBSFN subframe may use the subframe structure shown in Table 11 instead of Table 12 .

Up to now, the case of four or more transmit antennas has been described. Hereinafter, the case of one or two transmit antennas will be described.

Example  3

In the case of one or two transmit antennas, the position where the common reference signal exists is 0, 4, 7, 11th OFDM symbols in the case of the standard cyclic prefix, so that the first compared with the case of 4 or more transmit antennas OFDM symbols may be used. Accordingly, in consideration of this, in the case of one or two transmit antennas, Tables 9 and 10 may be modified to be prepared as Tables 13 and 14 below.

Table 13 below shows a combination of OFDM symbols on a subframe that can be used between a relay and an eNB, in case of one or two transmit antennas and a standard cyclic prefix.

case Channel transfer situation OFDM symbol index One PDCCH length ≤ 1 OFDM, PSCH (x), SSCH (x), PBCH (x) 1,2,3,5,6,8,9,10,12,13 2 PDCCH length ≤ 2 OFDMs, PSCH (x), SSCH (x), PBCH (x) 2,3,5,6,8,9,10,12,13 3 PDCCH length ≤ 3 OFDMs, PSCH (x), SSCH (x), PBCH (x) 3,5,6,8,9,10,12,13 4 PDCCH length ≤ 1 OFDM, PSCH (0), SSCH (0), PBCH (0) 1,2,3,12,13 5 PDCCH length ≤ 2 OFDMs, PSCH (0), SSCH (0), PBCH (0) 2,3,12,13 6 PDCCH length ≤ 3 OFDMs, PSCH (0), SSCH (0), PBCH (0) 3,12,13 7 PDCCH length ≤ 1 OFDM, PSCH (0), SSCH (0), PBCH (x) 1,2,3,8,9,10,12,13 8 PDCCH length ≤ 2 OFDMs, PSCH (0), SSCH (0), PBCH (x) 2,3,8,9,10,12,13 9 BPDCCH Length≤ 3 OFDMs, PSCH (0), SSCH (0), PBCH (x) 3,8,9,10,12,13

In Table 13, the length of the PDCCH is represented by an OFDM symbol occupied by the PDCCH on one subframe, and is equal to or less than one OFDM symbol, less than two OFDM symbols, or less than three OFDM symbols. Also, PSCH (x), SSCH (x), and PBCH (x) indicate a case in which PSCH, SSCH, and PBCH are not transmitted because the subframe does not correspond to the 0th and 5th subframes on the FDD frame. 0), SSCH (0) and PBCH (x) indicate a case in which the subframe corresponds to the fifth subframe on the FDD frame and transmits PSCH and SSCH but does not transmit PBCH, and PSCH (0) and SSCH ( 0), PBCH (0) indicates a case in which a subframe transmits a PSCH, an SSCH, and a PBCH corresponding to a 0 th subframe on an FDD frame.

In Table 13, Cases 1 to 3 represent remaining subframes except for the 0th and 5th frames on the FDD frame, Cases 3 to 6 represent the 0th subframe, and Cases 7 to 9 represent the fifth subframe. Therefore, when the OFDM symbol is used according to each case shown in Table 13 in the communication between the relay and the eNB, communication between the relay and the eNB is possible while supporting a legacy mobile terminal.

On the other hand, when the subframe is designated as MBSFN, when there are four or more transmit antennas and the extended cyclic prefix, the combination of OFDM symbols on the subframe that can be used between the relay and the eNB is shown in Table 14 below.

case Channel transfer situation OFDM symbol index One PDCCH length ≤ 1 OFDM, PSCH (x), SSCH (x), PBCH (x) 1,2,3,4,5,6,7,8,9,10,11,12,13 2 PDCCH length ≤ 2 OFDMs, PSCH (x), SSCH (x), PBCH (x) 2,3,4,5,6,7,8,9,10,11,12,13 3 PDCCH length ≤ 3 OFDMs, PSCH (x), SSCH (x), PBCH (x) 3,4,5,6,7,8,9,10,11,12,13 4 PDCCH length ≤ 1 OFDM, PSCH (0), SSCH (0), PBCH (0) 1,2,3,4, 11,12,13 5 PDCCH length ≤ 2 OFDMs, PSCH (0), SSCH (0), PBCH (0) 2,3,4, 11,12,13 6 PDCCH length ≤ 3 OFDMs, PSCH (0), SSCH (0), PBCH (0) 3,4, 11,12,13 7 PDCCH length ≤ 1 OFDM, PSCH (0), SSCH (0), PBCH (x) 1,2,3,4,7,8,9,10,11,12,13 8 PDCCH length ≤ 2 OFDM, PSCH (0), SSCH (0), PBCH (x) 2,3,4,7,8,9,10,11,12,13 9 PDCCH length ≤ 3 OFDMs, PSCH (0), SSCH (0), PBCH (x) 3,4,7,8,9,10,11,12,13

In Table 14, the length of the PDCCH is represented by an OFDM symbol occupied by the PDCCH on one subframe, and is equal to or less than one OFDM symbol, less than two OFDM symbols, or less than three OFDM symbols. Also, PSCH (x), SSCH (x), and PBCH (x) indicate a case in which PSCH, SSCH, and PBCH are not transmitted because the subframe does not correspond to the 0th and 5th subframes on the FDD frame. 0), SSCH (0) and PBCH (x) indicate a case in which the subframe corresponds to the fifth subframe on the FDD frame and transmits PSCH and SSCH but does not transmit PBCH, and PSCH (0) and SSCH ( 0), PBCH (0) indicates a case in which a subframe transmits a PSCH, an SSCH, and a PBCH corresponding to a 0 th subframe on an FDD frame.

In Table 14, Cases 1 to 3 represent remaining subframes except for the 0th and 5th, F3th frame, Cases 3 to 6 represent a 0th subframe, and Cases 7 to 9 represent a fifth subframe. Accordingly, when the OFDM symbol is used according to each case shown in Table 14 in the communication between the relay and the eNB, communication between the relay and the eNB is possible while supporting the legacy mobile terminal.

On the other hand, as described in the first embodiment, in order to prevent the mobile terminal from malfunctioning by the common reference signal, even if the subframe is designated as the MBSFN subframe may use the subframe structure shown in Table 13 instead of Table 14 .

Example  4

In the case of a normal cyclic prefix (normal CP), one subframe includes a total of 12 OFDM symbols from 0th to 12th. In addition, since one or two transmit antennas exist, the common reference signal exists in the 0th, 3rd, 6th, and 9th OFDM symbols of each subframe. Compared to the standard cyclic prefix, in the case of the extended cyclic prefix, the number of usable OFDM symbols in one subframe is reduced by two. In addition, in the FDD frame structure, the 0th and 5th subframes (represented as Subframe 0 and Subframe 5 in FIG. 3, respectively) may include a primary synchronization channel (PSCH) and a second synchronization channel for a synchronization siganl. A channel (Secondary Synchronization CHannel (SSCH)) is transmitted. In addition, the 0th subframe has a structure in which a physical broadcast channel (PBCH) is transmitted in addition to a synchronization signal. Therefore, in the system, the 0 th subframe should transmit the SSCH, the PSCH and the PBCH, and the 5 th subframe should transmit the SSCH and the PSCH. In particular, in the 0th and 5th subframes, the 4th OFDM symbol is an OFDM symbol for the SSCH, the 5th OFDM symbol is an OFDM symbol for the PSCH, and in the 0th subframe, the 6th to 9th OFDM symbols indicate a PBCH. OFDM symbol for.

In consideration of the above, in the case of one or two transmit antennas and extended cyclic prefix, a combination of OFDM symbols on a subframe that can be used between the relay and the eNB is shown in Table 15 below.

case Channel transfer situation OFDM symbol index One PDCCH length ≤ 1 OFDM, PSCH (x), SSCH (x), PBCH (x) 1, 2, 4, 5, 7, 8, 10, 11 2 PDCCH length ≤ 2 OFDMs, PSCH (x), SSCH (x), PBCH (x) 2, 4, 5, 7, 8, 10, 11 3 PDCCH length ≤ 3 OFDMs, PSCH (x), SSCH (x), PBCH (x) 4, 5, 7, 8, 10, 11 4 PDCCH length ≤ 1 OFDM, PSCH (0), SSCH (0), PBCH (0) 1, 2, 10, 11 5 PDCCH length ≤ 2 OFDMs, PSCH (0), SSCH (0), PBCH (0) 2, 10, 11 6 PDCCH length ≤ 3 OFDMs, PSCH (0), SSCH (0), PBCH (0) 10, 11 7 PDCCH length ≤ 1 OFDM, PSCH (0), SSCH (0), PBCH (x) 1,2,7,8,10,11 8 PDCCH length ≤ 2 OFDMs, PSCH (0), SSCH (0), PBCH (x) 2,7,8,10,11 9 PDCCH length ≤ 3 OFDMs, PSCH (0), SSCH (0), PBCH (x) 7,8,10,11

Further, in Table 15, the length of the PDCCH is represented by an OFDM symbol occupied by the PDCCH on one subframe, and is less than one OFDM symbol, less than two OFDM symbols, or less than three OFDM symbols. Also, PSCH (x), SSCH (x), and PBCH (x) indicate a case in which PSCH, SSCH, and PBCH are not transmitted because the subframe does not correspond to the 0th and 5th subframes on the FDD frame. 0), SSCH (0) and PBCH (x) indicate a case in which the subframe corresponds to the fifth subframe on the FDD frame and transmits PSCH and SSCH but does not transmit PBCH, and PSCH (0) and SSCH ( 0), PBCH (0) indicates a case in which a subframe transmits a PSCH, an SSCH, and a PBCH corresponding to a 0 th subframe on an FDD frame.

In Table 15, Cases 1 to 3 indicate remaining subframes except for the 0th and 5th frames on the FDD frame, Cases 3 to 6 represent the 0th subframe, and Cases 7 to 9 represent the fifth subframe. Therefore, when the OFDM symbol is used according to each case shown in Table 15 in the communication between the relay and the eNB, communication between the relay and the eNB is possible while supporting the legacy mobile terminal.

On the other hand, when a subframe is designated as MBSFN, one or two transmit antennas, and when the extended cyclic prefix, the combination of OFDM symbols on the subframe that can be used between the relay and the eNB is shown in Table 16 below. .

case Channel transfer situation OFDM symbol index One PDCCH length ≤ 1 OFDM, PSCH (x), SSCH (x), PBCH (x) 1,2,3,4,5,6,7,8,9,10,11 2 PDCCH length ≤ 2 OFDMs, PSCH (x), SSCH (x), PBCH (x) 2,3,4,5,6,7,8,9,10,11 3 PDCCH length ≤ 3 OFDMs, PSCH (x), SSCH (x), PBCH (x) 3,4,5,6,7,8,9,10,11 4 PDCCH length ≤ 1 OFDM, PSCH (0), SSCH (0), PBCH (0) 1,2,3,10,11 5 PDCCH length ≤ 2 OFDMs, PSCH (0), SSCH (0), PBCH (0) 2,3,10,11 6 PDCCH length ≤ 3 OFDMs, PSCH (0), SSCH (0), PBCH (0) 3,10,11 7 PDCCH Length = 1 OFDM, PSCH (0), SSCH (0), PBCH (x) 1,2,3,6,7,8,9,10,11 8 PDCCH length ≤ 2 OFDMs, PSCH (0), SSCH (0), PBCH (x) 2,3,6,7,8,9,10,11 9 PDCCH length ≤ 3 OFDMs, PSCH (0), SSCH (0), PBCH (x) 3,6,7,8,9,10,11

On the other hand, as described in the first embodiment, in order to prevent malfunction of the mobile terminal by the common reference signal, even if the subframe is designated as the MBSFN subframe may use the subframe structure shown in Table 15 instead of Table 16 .

The combination of OFDM symbols used when communication between the relay and the eNB described above has been described. Some OFDM symbols may be added or omitted by additional conditions in the ODFM symbol combination. That is, when a specific OFDM symbol is allocated for a new function, the specific OFDM symbol cannot be used in communication between the relay and the eNB. Therefore, in this case, the OFDM symbols except for the specific OFDM symbols may be used as the communication between the relay and the eNB in the combination of the OFDM symbols described above.

As a method of establishing communication between the relay and the eNB, various methods may be considered. First of all, the base station may refer to the subframe fixed by the semi-static in a fixed period. In this case, the communication between the relay and the eNB occurs only in specific subframes of a specific period, and the period may be set to an integer multiple of the period of a hybrid automatic repeat request (HARQ) process.

Another way is to dynamically designate a subframe to use for communication between the relay and the eNB. In this case, the relay may be informed in advance of the position of the next allocated subframe in a specific subframe that has already been indicated to the relay. In this case, if a specific subframe is lost, the connection between the relay and the eNB may be disconnected. Therefore, a subframe for dynamically communicating the relay and the eNB is set dynamically by setting a subframe for communication between the relay and the eNB at a semi-static period. In this case, communication disconnection that may occur due to an error between the relay and the eNB may be eliminated.

In each of the subframes configured as described above, OFDM symbols excluding various control channels or OFDM symbols for a specific purpose may be used for communication between the relay and the eNB. In this case, signal combinations may be classified as follows.

a) Combination of legacy structure control channel and data channel:

As a form of informing the allocation information on the relay through the PDCCH, it is suitable when the OFDM resource following the PDCCH is a legacy resource type. That is, it is easy to use when it has a structure like MBSFN. However, in order for the relay to view the PDCCH, there is a disadvantage in that the position at which the relay transmits the PDCCH and the time position at which the base station transmits the PDCCH are different from each other.

b) Combination of new control channel and data channel:

This is a form of informing allocation information to relay through new control channel. This is a structure for newly creating some of the OFDM symbol resources available for communication between the relay and the eNB as a control channel. In this case, the control channel structure may use both TDM / FDM structures among the usable OFDM symbols.

In the case of TDM, it is also possible to recycle the legacy PDCCH / PHICH / PCFICH structure. However, because of limited resources, it is more efficient to use only some subcarriers of one OFDM symbol as the control channel and to use the rest as data, rather than all frequency resources are allocated to the control channel in TDM format. . In case of setting the control channel with the FDM structure, the control channel can use both distributed resource mapping or localized resource mapping in the frequency domain allocated for the entire band or relay.

c) joint coding of control information and data:

This is a case where each relay knows in advance where data should be received, which corresponds to a case where a base station informs the position of a resource in advance quasi-statically or in a previous subframe. In this case, the relay receives a signal at a specific time-frequency resource location and decodes it. The encoding of the control information and the data portion is performed by joint coding only the control information and only the data portion. It is possible to set the encoding by forming a set separately or by encoding the control information and the data part into a set. In this case, the control information and the data information may be information grouped in one relay unit, but assuming that the performance of the relay is sufficient, joint coding may be performed by combining the control information and data information of other relays together. As described above, if the structure does not utilize all the remaining OFDM symbols except for the PDCCH, the structure used in the existing PDSCH cannot be used as it is, and a new structure must be made.

Meanwhile, the transport block size (TBS) is referred to as a logical index on the MCS table, and the actual TBS value depends on the number of resource blocks allocated to the resource.

Therefore, in order to correct the TBS for the relay, the relay TBS table may be newly defined or configured by correcting an offset value from the existing TBS table.

At this time, the configuration of the offset value, except for the guard time or control channel configuration caused by the relay operation (data traffic) may exist for the remaining area. Therefore, as much value as the relay-related additional information can be defined and used according to RB.

The usable OFDM symbol described in the present invention shows the positions where the eNB and the relay can be transmitted without any problem in the transmission of the downlink control channel of the relay cell. In fact, in order to be able to use an OFDM symbol, there must be a guard time on both sides of the OFDM symbol. Considering this, the position of one OFDM symbol adjacent to the control channel is not suitable for use. not. Instead, only OFDM symbols that can be used adjacent to each other are suitable for use in consideration of the guard time, and preferably, so that a transition between the control channel of the relay cell and the OFDM symbols available between the eNB and the relay does not occur frequently. It is desirable to.

That is, for example, one block is selected among positions where adjacent OFDM symbols are available in one subframe (for example, the last OFDM symbols in the subframe), and only the corresponding part transmits control channel and / or data between the eNB and the relay. It is preferable to use the rest as an access link of the relay cell.

In addition, in order for data transmission between the eNB and the relay to maintain alignment with other subcarriers, two consecutive OFDM symbols transmit the same symbol for a subcarrier used as a link between the eNB and the relay. It is desirable to use the form in which phase continuity is maintained. In this case, when the macro UE uses an adjacent band, inter-subcarrier interference (ICI) interference does not occur.

In the present specification, embodiments of the present invention have been described based on data transmission / reception relations between an eNB and a mobile terminal. Here, the eNB has a meaning as a terminal node of a network that directly communicates with the terminal. Certain operations described as performed by the eNB in this document may be performed by an upper node of the eNB in some cases.

That is, various operations performed for communication with the UE in a network composed of a plurality of network nodes including an eNB may be performed by the eNB or other network nodes other than the eNB. In this case, the eNB may be replaced by terms such as a fixed station, a Node B, and an access point. In addition, in the present invention, a mobile station (MS) corresponds to a user equipment (UE), and a mobile station (MS) is a subscriber station (SS), a mobile subscriber station (MSS), or a terminal (MS). Mobile terminal).

On the other hand, the user device of the present invention PDA (Personal Digital Assistant), cellular phone, PCS (Personal Communication Service) phone, GSM (Global System for Mobile) phone, WCDMA (Wideband CDMA) phone, MBS (Mobile Broadband System) phone And the like can be used.

Embodiments of the invention 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, the method according to embodiments of the present invention may include one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs). Field programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, and the like.

In the case of an implementation by firmware or software, the method according to the embodiments of the present invention may be implemented in the form of a module, a procedure, or a function that performs 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 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 construed 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. In addition, claims that do not have an explicit citation in the claims may be combined to form an embodiment or included in a new claim by amendment after the application.

The description of the above embodiments may be applied to a 3GPP LTE-based system as well as a 3GPP LTE-A system supporting relay.

1 is a configuration diagram of a relay system.

2 illustrates a frame structure for supporting a relay in a conventional broadband wireless access system.

FIG. 3 illustrates a radio frequency division duplexing (FDD) frame structure of a 3GPP LTE system in the case of a normal Cyclic Prefix (normal CP).

FIG. 4 illustrates a radio frequency division duplexing (FDD) frame structure of a 3GPP LTE system in the case of a normal cyclic prefix (normal CP).

FIG. 5 shows the structure of an OFDM symbol used by a relay in one subframe in the case of standard cyclic prefix.

FIG. 6 illustrates a structure of an OFDM symbol used by a relay in one subframe in the case of an extended cyclic prefix (extended CP).

Claims (14)

In a system supporting a legacy system, a base station transmits data to a relay. Generating, by the base station, a subframe for transmitting data to the relay; And Transmitting the generated subframe to the relay, The subframe includes a predetermined number of OFDM symbols, and the OFDM symbols used by the base station to transmit data to the relay among the predetermined number of OFDM symbols are controlled by the relay to legacy user equipment supported by the legacy system. Except for the OFDM symbol overlapping with the OFDM symbol used to transmit the channel and the reference signal (Reference Signal), A method for transmitting data from a base station to a relay. The method of claim 1, The subframe includes 14 OFDM symbols, and when each of the 14 OFDM symbols is sequentially indexed from 0 to 13 on the time axis, the OFDM symbol used by the base station to transmit data to the relay is Corresponding to any one of cases 1 to 6 of Table 17 below, How a base station sends data to a relay: case  OFDM symbol index for the base station to transmit data to the relay One  2, 3, 5, 6, 9, 10, 12, 13 2  3, 5, 6, 9, 10, 12, 13 3  2, 3, 12, 13 4  3, 12, 13 5  2, 3, 9, 10, 12, 13 6  3, 9, 10, 12, 13 The method of claim 1, The subframe is designated an MBSFN subframe, and the one subframe includes 14 OFDM symbols, and when the 14 OFDM symbols are sequentially indexed from 0 to 13 on the time axis, the base station The OFDM symbol used to transmit data to the relay corresponds to any one of cases 1 to 6 of Table 18 below. How a base station sends data to a relay: case  OFDM symbol index for the base station to transmit data to the relay One  2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 2  3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 3  2, 3, 4, 11, 12, 13 4  3, 4, 11, 12, 13 5  2, 3, 4, 7, 8, 9, 10, 11, 12, 13 6  3, 4, 7, 8, 9, 10, 11, 12, 13 The method of claim 1, The subframe includes 12 OFDM symbols, and when each of the 12 OFDM symbols is sequentially indexed from 0 to 11 on the time axis, the OFDM symbol used by the base station to transmit data to the relay is Corresponding to any one of cases 1 to 6 of Table 19 below, How a base station sends data to a relay: case  OFDM symbol index for the base station to transmit data to the relay One  2, 4, 5, 8, 10, 11 2  4, 5, 8, 10, 11 3  2, 10, 11 4  10, 11 5  2, 8, 10, 11 6  8, 10, 11 The method of claim 1, The one subframe is designated as an MBSFN subframe, and the one subframe includes 12 OFDM symbols, when time is sequentially indexed from 0 to 11 on the time axis to each of the 12 OFDM symbols. The OFDM symbol used by the base station to transmit data to the relay corresponds to any one of cases 1 to 6 of Table 20 below. How a base station sends data to a relay: case  OFDM symbol index for the base station to transmit data to the relay One  2, 3, 4, 5, 6, 7, 8, 9, 10, 11 2  3, 4, 5, 6, 7, 8, 9, 10, 11 3  2, 3, 10, 11 4  3, 10, 11 5  2, 3, 4, 7, 8, 9, 10, 11 6  3, 4, 7, 8, 9, 10, 11 The method of claim 1, The one subframe includes 14 OFDM symbols, and when each 14 OFDM symbols are sequentially indexed from 0 to 13 on the time axis, the base station uses the OFDM to transmit data to the relay The symbol corresponds to any one of cases 1 to 9 of Table 21 below, How a base station sends data to a relay: case  OFDM symbol index for the base station to transmit data to the relay One  1, 2, 3, 5, 6, 8, 9, 10, 12, 13 2  2, 3, 5, 6, 8, 9, 10, 12, 13 3  3, 5, 6, 8, 9, 10, 12, 13 4  1, 2, 3, 12, 13 5  2, 3, 12, 13 6  3, 12, 13 7  1, 2, 3, 8, 9, 10, 12, 13 8  2, 3, 8, 9, 10, 12, 13 9  3, 8, 9, 10, 12, 13 The method of claim 1, The one subframe is designated as an MBSFN subframe, and the one subframe includes 14 OFDM symbols. When the 14 OFDM symbols are sequentially indexed from 0 to 13 on the time axis, The OFDM symbol used by the base station to transmit data to the relay corresponds to any one of cases 1 to 9 of Table 22 below. How a base station sends data to a relay: case  OFDM symbol index for the base station to transmit data to the relay One  1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 2  2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 3  3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 4  1, 2, 3, 4, 11, 12, 13 5  2, 3, 4, 11, 12, 13 6  3, 4, 11, 12, 13 7  1, 2, 3, 4, 7, 8, 9, 10, 11, 12, 13 8  2, 3, 4, 7, 8, 9, 10, 11, 12, 13 9  3, 4, 7, 8, 9, 10, 11, 12, 13 The method of claim 1, The one subframe includes 12 OFDM symbols, and when each of the 12 OFDM symbols are sequentially indexed from 0 to 11 on the time axis, the base station uses for transmitting data to the relay The symbol corresponds to any one of cases 1 to 9 of Table 23 below, How a base station sends data to a relay: case  OFDM symbol index for the base station to transmit data to the relay One  1, 2, 4, 5, 7, 8, 10, 11 2  2, 4, 5, 7, 8, 10, 11 3  4, 5, 7, 8, 10, 11 4  1, 2, 10, 11 5  2, 10, 11 6  10, 11 7  1, 2, 7, 8, 10, 11 8  2, 7, 8, 10, 11 9  7, 8, 10, 11 The method of claim 1, The one subframe is designated an MBSFN subframe, and the one subframe includes 12 OFDM symbols, and when each of the 12 OFDM symbols is sequentially indexed from 0 to 11 on the time axis, The OFDM symbol used by the base station to transmit data to the relay corresponds to any one of cases 1 to 9 of Table 24 below. How a base station sends data to a relay: case  OFDM symbol index for the base station to transmit data to the relay One  1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 2  2, 3, 4, 5, 6, 7, 8, 9, 10, 11 3  3, 4, 5, 6, 7, 8, 9, 10, 11 4  1, 2, 3, 10, 11 5  2, 3, 10, 11 6  3, 10, 11 7  1, 2, 3, 6, 7, 8, 9, 10, 11 8  2, 3, 6, 7, 8, 9, 10, 11 9  3, 6, 7, 8, 9, 10, 11 The method of claim 1, Information on the time and frequency resource location where the data is located on the subframe is transmitted through a physical downlink control channel (PDCCH), A method for transmitting data from a base station to a relay. The method of claim 1, Assigning a portion of the OFDM symbol used by the base station to transmit the data to the relay as a control channel for transmitting information about a time and frequency resource location where the data is located on the subframe, A method for transmitting data from a base station to a relay. The method of claim 1 wherein the method And transmitting, by the base station, information about a time and frequency resource location at which the data is located on the subframe to the relay at a predetermined period. A method for transmitting data from a base station to a relay. The method of claim 1, The control channel includes a Physical Control Format Indicator CHannel (PCFICH), a Physical Downlink Control CHannel (PDCCH), and a Physical Hybrid ARQ Indicator CHannel (PHICH). A method for transmitting data from a base station to a relay. The method of claim 13, The control channel Further comprising at least one of a Primary Synchronization CHannel (PSCH), a Secondary Synchronization CHannel (SSCH), and a Physical Broadcast CHannel (PBCH), A method for transmitting data from a base station to a relay.

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