KR101642413B1 - Method and Apparatus for Allocating Backhaul Transmission Resource of in wireless communication systems based on relay - Google Patents

Abstract

In the relay-based wireless communication system of the present invention, a method of allocating an uplink backhaul resource for a relay node includes an information acquisition step of acquiring scheduling information for an uplink backhaul transmission from a base station through a downlink backhaul control channel, Checking whether a link backhaul subframe is set to transmission of a sounding reference signal (SRS), checking whether a subframe that does not include the SRS is scheduled, And a multiplexing step of multiplexing the blank, the RS, and the SRS in the allocated resource area, and a multiplexing step of multiplexing the blank, the RS, and the SRS in the allocated resource area, The method comprising the steps of:

According to the present invention, the superposition phenomenon of the transmission / reception timing of the relay node due to the RF transmission / reception switching time delay is eliminated, compatibility with the conventional uplink and downlink subframe structures is provided, Thereby minimizing the effect on the system of FIG.

OFDM, linear equalizer

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method and apparatus for allocating resources for backhaul transmission in a relay-based wireless communication system,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless relay in a wireless communication system, and more particularly, to a method and apparatus for designing an uplink and downlink backhaul subframe for a Layer-3 (hereinafter referred to as L3) relay including a base station function.

In recent mobile communication systems, a single carrier frequency division multiple access (OFDM) scheme or a single carrier frequency division multiple access (OFDM) scheme, which is a useful method for high speed data transmission in a wireless channel, SC-FDMA) has been actively studied. Currently, OFDM and SC-FDMA techniques are applied in the downlink and uplink of the Evolved UMTS Terrestrial Radio Access (EUTRA) standard based on the 3rd Generation Partnership Project (3GPP) UMTS (Universal Mobile Telecommunication Services). SC-FDMA is a technique based on single carrier transmission, which guarantees orthogonality among multiple access users as well as OFDM, and is advantageous in that the peak to average power ratio (PAPR) of a transmission signal is low. Therefore, when SC-FDMA is applied to a mobile communication system, cell coverage can be improved due to low PAPR compared with OFDM technology.

Because LTE-Advanced (LTE-A) systems transmit data at a higher rate than LTE systems, new techniques are needed to compensate for signal distortion. Signal distortion due to channel path loss is a fundamental limitation in transmitting data at a limited rate at high speed. To overcome this, the wireless relay technology places a wireless relay node between the first transmitting end and the last receiving end, and the wireless relay node compensates the path loss of the signal transmitted from the first transmitting end and transmits the compensated path to the final receiving end. Therefore, the wireless relay technology improves the performance of the cell edge terminal and improves the system coverage by improving the path loss occurring between the original transmitting end and the last receiving end.

On the other hand, when the wireless relay node simultaneously performs signal reception and transmission, the transmission signal acts as a large interference of the reception signal. Therefore, it is necessary to distinguish between the receiving link and the transmitting link of the wireless relay node. The transmission and reception links of the wireless relay node can be classified as shown in Table 1 below.

<Table 1>

Time division method Separates the transmit and receive links into different time resources in the same frequency band. Frequency division method Separates the transmit and receive links from the same time resource into different frequency resources

Since the frequency division scheme of Table 1 requires a wide interval between two frequency bands in order to avoid interference between frequency bands, time division link classification is generally used for efficient allocation of frequency resources.

The wireless relay system can be classified into four types according to the function of the relay node as shown in Table 2 below.

<Table 2>

Layer-0 (L0) relay Amplify and transmit all received signals Layer-1 (L1) relay Amplify and transmit the received signal Layer-2 (L2) relay Demodulate, decode, encode, and transmit the received signal Layer-3 (L3) relay Perform base station function including relay function

According to the L3 relay system of Table 2, it is possible to distinguish the relay node cell and the base station cell, improve the frequency resource utilization, and facilitate the introduction of the wireless relay to the cellular system.

The uniqueness of the L3 relay system is a wireless backhaul link between the base station and the relay node. The wireless backhaul link means that the relay node receives the downlink data of the terminals belonging to the relay node from the base station or the relay node transmits the uplink data of the terminals to the base station and the relay node transmits the wireless backhaul link and the terminal And time-division method.

The relay node must perform the RF transmission / reception switching before and after the backhaul subframe, and this operation causes the RF transmission / reception switching time delay at the relay node. Therefore, the uplink and downlink backhaul subframe structures in the L3 relay system should be designed in consideration of compatibility between the RF transmission / reception switching time delay and general uplink and downlink subframe structures.

A method and apparatus for allocating a backhaul transmission resource in a relay-based wireless communication system, the present invention provides an uplink backhaul subframe structure and a downlink backhaul subframe structure in an L3 relay system. In particular, the method and apparatus for allocating a backhaul transmission resource in a relay-based wireless communication system according to the present invention reduce the RF transmission / reception switching time delay inevitably caused by using the relay L3, And to provide an uplink and a downlink backhaul subframe structure that are compatible with each other.

In order to solve the above problems, a method of allocating uplink backhaul transmission resources of a relay node in a relay-based wireless communication system of the present invention includes acquiring scheduling information for uplink backhaul transmission from a base station through a downlink backhaul control channel Checking whether the uplink sub-frame is configured to transmit a sounding reference signal (SRS) through the scheduling information, if it is determined that the sub-frame not including the SRS is scheduled, A data mapping step of performing rate matching and mapping of data excluding a symbol for blank and a symbol for a reference signal (RS) in an allocated resource area; And multiplexing the RS and the SRS And that is characterized.

Also, in the relay-based wireless communication system of the present invention for solving the above problems, a method for allocating uplink backhaul resources for a base station includes scheduling downlink resources of a relay node and downlink resources of terminals belonging to a base station cell A scheduling step of mapping the scheduled control symbols of the relay node and the UEs to a downlink control channel (PDCCH) region, and transmitting data symbols of the scheduled UE to a physical downlink shared channel, A first mapping step of mapping the PDSCH to a PDSCH region of a relay node corresponding to a PDSCH region excluding one symbol for switching time delay located at the end of a subframe and N symbols used for PDCCH transmission of a relay node, Rate matching the data, A second mapping step of mapping the matched data symbols to a PDSCH region excluding N + 1 symbols located at the end of the subframe, and a multiplexing step of multiplexing PDCCH, PDSCH and RS of the scheduled relay node and the UE .

Also, in the relay-based wireless communication system of the present invention for solving the above problems, an uplink backhaul resource allocation apparatus of a relay node includes a sounding reference signal (SRS), a reference signal (RS) A plurality of symbol generators for generating PUSCH symbols, a Fast Fourier Transform (FFT) unit for receiving the PUSCH symbols and converting the PUSCH symbols into frequency band signals, the SRS symbols, A subcarrier symbol mapper for receiving the RS symbol and the Fourier transformed PUSCH symbols and mapping the subcarrier symbol to an allocated resource region, and a symbol generator for generating the PUSCH symbol to perform rate matching in consideration of a blank symbol, The input symbols are mapped in an area excluding a blank symbol in the mapper And an uplink physical channel symbol generation and mapping controller for controlling the uplink physical channel symbol generation and control.

In addition, in the relay-based wireless communication system of the present invention for solving the above problems, a base station downlink backhaul resource allocation apparatus includes a reference signal (RS) subcarrier symbol, a physical downlink control channel (PDCCH) A plurality of symbol generators for generating a sub-carrier symbol and a PDSCH sub-carrier symbol, a sub-carrier for receiving the RS sub-carrier symbol, the PDCCH sub-carrier symbol, and the PDSCH sub- A symbol mapper, and a symbol generator for generating the PDSCH subcarrier symbol to perform rate matching of data in consideration of symbols for blanking, and in the subcarrier symbol mapper, the inputted symbols control the corresponding sub- To be mapped to a frame And a downlink physical channel symbol generation and mapping controller for controlling the downlink physical channel.

According to the present invention, the superposition phenomenon of the transmission / reception timing of the relay node due to the RF transmission / reception switching time delay is eliminated, compatibility with the conventional uplink and downlink subframe structures is provided, To minimize the impact on the system.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the same components are denoted by the same reference numerals as possible in the accompanying drawings. Further, the detailed description of well-known functions and constructions that may obscure the gist of the present invention will be omitted.

In describing the embodiments of the present invention, SC-FDMA and OFDM-based wireless communication systems, particularly 3GPP EUTRA standard, will be the main object, but the main point of the present invention is to provide The present invention can be applied to other communication systems without departing from the scope of the present invention, and this can be done by a person skilled in the art.

1 is a block diagram showing a structure of a SC-FDMA transmitter and a slot structure thereof. In particular, the transmitter shown in FIG. 1 is characterized by using a Fast Fourier Transform (FFT) apparatus 103 and an Inverse Fast Fourier Transform (IFFT) apparatus 105.

1, an OFDM transmitter has an IFFT unit 105 used for multi-carrier transmission, whereas the SC-FDMA transmitter has an IFFT unit 105 in an OFDM transmitter. Lt; RTI ID = 0.0 &gt; 105 &lt; / RTI &gt; The M modulation symbols 100 are gathered to form one block, which is input to the FFT unit 103 of size M. [ The block is hereinafter referred to as an LB (Long Block), and the seven LBs constitute one 0.5 ms slot 102. The LB after the FFT processing becomes the SC-FDMA symbol, and the seven SC-FDMA symbols constitute one 0.5 ms slot.

The signal output from the FFT unit 103 is applied to the inputs of the IFFT unit 105 having a continuous index (104), subjected to reverse fast Fourier transform, and then converted into an analog signal 106 and transmitted. The input / output size N of the IFFT apparatus 105 is larger than the input / output size M of the FFT 103. [ The reason why the SC-FDMA transmission signal has a lower PAPR (Peak-to-Average Power Ratio) than the OFDM signal is that the signal processed through the FFT unit 103 and the IFFT unit 105 has a single carrier characteristic It is because it has.

2 is a diagram illustrating an SC-FDMA-based uplink and OFDM-based downlink frame structure of EUTRA, which is a 3GPP next generation mobile communication technology standard.

Referring to FIG. 2, a total of 50 resource blocks (RBs) 202 exist in a system bandwidth 201 of 10 MHz. One RB is composed of 12 subcarriers 203 and may have 14 SC-FDMA symbol intervals 204 in the case of uplink and 14 OFDM symbol intervals 206 in the case of downlink. have. Here, the SC-FDMA symbol interval and the OFDM symbol interval are the same, and each RB is a basic data transmission scheduling unit. 14 SC-FDMA symbols or OFDM symbols are gathered to form one 1-ms sub-frame 205.

3 is a diagram illustrating a resource allocation structure for uplink control channel and data channel transmission based on SC-FDMA in an LTE (Long Term Evolution) system.

3, a physical uplink control channel (PUCCH) 306 is transmitted from RBs located at both ends of a system band, and a sounding reference signal (SRS) Is transmitted over the 10 MHz full band 303 of the last SC-FDMA symbol 305, and each SRS of the users in the cell is guaranteed to be orthogonal. The PUSCH 307 is transmitted in an area excluding the PUCCH and the SRS area of the system band and the reference signal (RS) 308 is transmitted in each slot 302 ) In the middle of the SC-FDMA symbol.

PUCCH includes ACK (acknowledgment) / NACK (Negative ACK) information for HARQ (Hybrid Automatic Repeat reQuest) operation and CQI (Channel Quality Indication) for scheduling downlink data. Also, the SRS is a signal for acquiring uplink channel state information and uplink transmission timing adjustment for each user in the entire system band, and RS is a signal for obtaining channel state information used for demodulation and decoding of the PUSCH.

4 is a diagram illustrating a resource allocation structure for OFDM-based downlink control channel and data channel transmission in an LTE system.

Referring to FIG. 4, one subframe is composed of 14 OFDM symbols 400 to 413, and an area allocated for a PDCCH is allocated in front of a subframe And can allocate up to three OFDM symbols 400 to 402 in at least one OFDM symbol 400. In particular, in FIG. 4, the first two OFDM symbols 400 and 401 are allocated. Also, the allocated area for the PDSCH is the remaining 12 OFDM symbols 402 to 413.

A Physical Control Format Indicator Channel (PCFICH) indicating the length of the PDCCH region and a PHICH (Physical Hybrid ARQ Indicator Channel) indicating ACK / NACK information are transmitted to the first OFDM symbol of the PDCCH region. The PDCCH includes user data allocation information and data modulation and coding scheme (MCS) information. On the other hand, the reason for locating the area for the PDCCH at the forefront of the subframe is that if the UE first confirms the PDCCH and there is no corresponding data allocation information, it takes a micro sleep mode, . In the PDCCH region and the PDSCH region, RSs are dispersively located for demodulation and decoding of each channel.

Hereinafter, the uplink and downlink backhaul subframe structures for wireless backhaul communication will be described when introducing the L3 relay system. Particularly, it is possible to maintain compatibility with the conventional SC-FDMA based uplink subframe structure and OFDM based downlink subframe structure, and to improve the RF transmission / reception switching time delay inevitably caused by using the L3 relay system The link backhaul subframe structure and the downlink backhaul subframe structure will be described.

&Lt; Embodiment 1 >

5 is a diagram illustrating an uplink subframe structure of an L3 relay system for an uplink backhaul according to the first embodiment of the present invention. Particularly, the first embodiment considers the case where SRS transmission is allowed in an uplink backhaul subframe. The SRS is used to adjust the transmission timing of the relay node, and the channel state information for the frequency domain of the wireless backhaul link obtained by the base station via the SRS is used for scheduling wireless backhaul resources.

Referring to FIG. 5, since the relay node RN can not receive the uplink sub-frame 501 during the uplink sub-frame 501 transmitted from the relay node RN to the base station eNB, The uplink resources are not allocated to the UEs. In the period other than the uplink backhaul subframe, the relay node performs the reception operation of the signals transmitted from the UEs during the uplink subframes 505 and 506 of the terminals belonging to the relay node cell during this interval.

Also, the synchronization of the uplink sub-frame of the uplink of the relay node coincides with the synchronization of the uplink sub-frame of the UEs belonging to the base station cell. Therefore, the SRS 503 in the uplink backhaul subframe should be located in the last SC-FDMA symbol, which is the same position as the general surf frame structure, in order to maintain orthogonality with the SRS transmission of the UEs belonging to the base station cell.

Meanwhile, the PUSCH 509 and RS 507 structures in the uplink backhaul subframe follow the conventional PUSCH 510 and RS 508 structures to enable uplink resource allocation of UEs belonging to the base station cell. Therefore, uplink resources of UEs belonging to the relay node cell can be transmitted by frequency division multiplexing (FDM) in the PUSCH 510 area of the UL access subframes 505 and 506, The uplink backhaul resource of the relay node and the uplink resources of the UEs belonging to the base station cell can be frequency division multiplexed and transmitted in the PUSCH 509 area of the base station 501.

On the other hand, switching from RF reception to RF transmission is required immediately before transmission of the uplink backhaul subframe, and switching from RF transmission to RF reception is required immediately after transmission of the uplink backhaul subframe. The resulting RF transmission / reception switching time delay should be considered in the uplink backhaul subframe 501.

In the case of the first embodiment, the RF transmission / reception switching time delay is considered while maintaining the proposed subframe structure. That is, the relay node waits for the transmission of the first SC-FDMA symbol 502 and forwards the transmission timing of the UL access sub-frame 506, which is the timing at which the UE transmits to the relay node, backward by the RF transmission / reception switching time delay Consider the switching time delay in the first SC-FDMA symbol interval 502 of the uplink backhaul subframe 501.

6 is a flowchart illustrating a transmission procedure of a relay node for an uplink backhaul in the L3 relay system according to the first embodiment of the present invention.

Referring to FIG. 6, in step 600, the relay node obtains scheduling information for uplink backhaul transmission from the base station. This scheduling information can be obtained through the control channel of the downlink backhaul transmitted from the base station to the relay node. In step 601, the relay node determines whether the scheduled uplink backhaul subframe is set to transmit the SRS. This check operation is required because the PUSCH area of the subframe including the SRS and the subframe not including the SRS are different. That is, in the case of a subframe including SRS, the last SC-FDMA symbol is excluded in the PUSCH region, and in the case of the subframe including no SRS, the last SC-FDMA symbol is included in the PUSCH region.

If it is determined in step 601 that the scheduled uplink backhaul subframe transmits the SRS, in step 602, the relay node allocates SC-FDMA symbols for blanks, SC-FDMA symbols for RSs, and SRSs for RSs in the allocated RB resources. Rate matching of data is performed in consideration of the resource region excluding the SC-FDMA symbol. In addition, in step 603, the relay node maps the rate matched data symbols to the resource areas excluding the first SC-FDMA symbol for blank, the fourth and eleventh SC-FDMA symbols for RS, and the last SC-FDMA symbol for SRS. Subsequently, in step 604, a blank is multiplexed on the first SC-FDMA symbol, RS is multiplexed on the fourth and eleventh SC-FDAM symbols, and SRS is multiplexed on the last SC-FDMA symbol.

If it is determined in step 601 that the scheduled uplink backhaul subframe does not transmit the SRS, in step 605, the relay node allocates the resource area excluding the SC-FDMA symbol for the blank and the SC-FDMA symbol for the RS in the allocated RB resource And perform rate matching of the data. In step 606, the relay node maps the rate-matched data symbols to the resource areas excluding the first SC-FDMA symbol for the blank and the fourth and eleventh SC-FDMA symbols for the RS. Subsequently, in step 607, blanks are multiplexed on the first SC-FDMA symbol, and RSs are multiplexed on the fourth and eleventh SC-FDAM symbols to transmit to the base station.

7 is a flowchart illustrating a reception procedure of a base station for an uplink backhaul in a wireless communication L3 relay system according to the first embodiment of the present invention.

Referring to FIG. 7, the BS determines in step 701 whether the received subframe is set to transmit SRS. If it is determined in step 701 that the received subframe is set to transmit SRS, in step 702, the base station demultiplexes the SRS, RS, and PUSCH in the received subframe. In step 703, the data symbols of the PUSCH region except for the first SC-FDMA symbol are de-mapped in the RBs allocated to the uplink backhaul. In step 704, the base station decodes the demapped data symbols to obtain uplink backhaul data.

On the other hand, if it is determined in step 701 that the received subframe is set not to transmit the SRS, the base station demultiplexes the RS and the PUSCH in the received subframe in step 705. In step 706, the data symbols of the PUSCH area excluding the first SC-FDMA symbol are de-mapped in the RB resources allocated to the uplink backhaul. In step 707, the base station decodes the demapped data symbols, Obtain backhaul data.

Although one SC-FDMA symbol for a blank is considered in the first embodiment, one or more SC-FDMA symbols for blanks may be considered according to variable values related to RF transmission / reception switching time delay and timing adjustment.

&Lt; Embodiment 2 >

8 is a diagram illustrating an uplink subframe structure of an L3 relay system for an uplink backhaul according to a second embodiment of the present invention. In particular, the second embodiment is limited to the case where the uplink backhaul subframe does not transmit the SRS.

Referring to FIG. 8, since the relay node can not receive the uplink backhaul subframe 801 transmitted from the relay node RN to the base station eNB as described above, The uplink resources are not allocated to the UEs belonging to the node cell. Since the relay node performs a reception operation in an interval other than the uplink backhaul subframe, the relay node receives the signals transmitted from the terminals in the uplink access subframes (804, 805) of the terminals belonging to the relay node cell .

Also, since the synchronization of the uplink sub-frame of the uplink of the relay node coincides with the synchronization of the uplink sub-frame of the UEs belonging to the base station cell. The PUSCH 808 and RS 806 structures in the UL backhaul subframe use the conventional PUSCH 809 and RS 807 structures to enable uplink resource allocation of UEs belonging to the base station cell. Therefore, uplink resources of UEs belonging to the relay node cell can be frequency-division multiplexed and transmitted in the PUSCH 809 region of the UL subframes 804 and 805, and the PUSCH 809 of the uplink sub- The uplink backhaul resource of the relay node and the uplink resources of the UEs belonging to the base station cell may be frequency-division multiplexed and transmitted.

On the other hand, switching from RF reception to RF transmission is required immediately before transmission of the uplink backhaul subframe, switching from RF transmission to RF reception is required immediately after transmission of the uplink backhaul subframe, and RF transmission / reception switching time delay is raised Link backhaul sub-frame &lt; RTI ID = 0.0 &gt; 801. &lt; / RTI &gt; However, in the second embodiment, unlike the first embodiment, the transmission of the last SC-FDMA symbol interval 802 is abandoned. This is because the synchronization of the UL backhaul subframe of the relay node coincides with the synchronization of the uplink subframe of the UEs belonging to the base station cell and the UL backhaul subframe does not transmit the SRS, This is to prevent collision of backhaul data.

When the relay node discards the transmission of the last SC-FDMA symbol, the transmission timing of the uplink access link, which is the timing at which the relay node transmits to the relay node, is advanced by the RF transmission / reception switching time delay, Consider the switching time delay in the FDMA symbol interval 802.

The transmission procedure of the relay node according to the second embodiment corresponds to a step 605 to a step 607 in the case of a subframe without SRS transmission in FIG. 6, and the reception procedure of the base station corresponds to a subframe in which no SRS transmission is performed in FIG. Corresponds to steps 705 to 707, which are cases. However, unlike the first embodiment, the use of the last SC-FDMA symbol for the blank is applied in steps 606, 607, and 706. Also, in the second embodiment, one SC-FDMA symbol for a blank is considered, but one or more SC-FDMA symbols for a blank may be considered according to variable values related to RF transmission / reception switching time delay and timing adjustment.

&Lt; Third Embodiment >

9 is a diagram illustrating a downlink subframe structure of an L3 relay system for a downlink backhaul according to a third embodiment of the present invention.

9, the relay node RN transmits a PDCCH 912 to UEs belonging to a relay node immediately before receiving a downlink backhaul subframe from a base station eNB, The PDCCH 902 and the PDSCH 903 of the UEs belonging to the base station cell can be frequency division multiplexed and transmitted in the link backhaul subframe. This structure is to maintain compatibility with the conventional LTE system.

Also in the third embodiment, the RF transmission / reception switching time delay occurs at the immediately preceding reception 906 and immediately after reception 907 of the downlink backhaul subframe. In order to reflect this switching time delay in the backhaul subframe, the base station does not use the last OFDM symbol in the downlink backhaul transmission.

9, the backhaul reception interval of the relay node is the PDSCH interval 913 immediately after the PDCCH 912 transmission of the relay node. Therefore, the last OFDM symbol interval that should be set to be empty in the base station is the RF transmission / reception switching time delay In addition, the interval of the PDCCH 912 transmitted by the relay node should be considered. That is, a resource that the BS does not use for resource allocation in the downlink backhaul subframe includes one OFDM symbol for switching time delay and N + 1 OFDM symbols added to N OFDM symbols used for transmission of the PDCCH 912 of the relay node Symbol. This applies to the last OFDM symbols 905 of the backhaul resource in the downlink backhaul subframe. Here, the length of the PDCCH 912 region transmitted by the relay node may be fixed or may be changed through an upper signal. The relay node can adjust the timing with the terminal belonging to the relay node cell based on the reception timing of the downlink backhaul subframe as shown in FIG.

10 is a flowchart illustrating a transmission procedure of a base station for a downlink backhaul in an L3 relay system according to a third embodiment of the present invention.

Referring to FIG. 10, in step 1000, the BS schedules the downlink resource of the relay node and the downlink resources of the MSs belonging to the BS cell. Also, in step 1001, the control symbols of the relay node and the UE scheduled are mapped to the PDCCH area, and the data symbols of the UE scheduled in step 1002 are mapped to the PDSCH area.

Subsequently, in step 1003, rate matching is performed considering the PDSCH region excluding N + 1 OFDM symbols with respect to the data of the scheduled relay node. In step 1004, the rate matched data symbols are mapped to the PDSCH area excluding the last N + 1 OFDM symbols. In step 1005, the base station multiplexes the PDCCH, the PDSCH, and the RS of the relay node and the UE, and transmits the result.

11 is a flowchart illustrating a procedure of receiving a relay node for a downlink backhaul in an L3 relay system according to a third embodiment of the present invention.

Referring to FIG. 11, in step 1100, the PDCCH, the PDSCH, and the RS are demultiplexed in the downlink backhaul subframe received from the base station. In step 1101, the relay node decodes the corresponding PDCCH to obtain scheduling information (i.e., resource allocation information and modulation and coding level) of the downlink backhaul. In addition, the data symbol is demapped in an area excluding the last N + 1 OFDM symbols among the allocated PDSCH areas in step 1102, and the relay node decodes the demapped data symbols in step 1103 to obtain downlink backhaul data.

In the third embodiment, one OFDM symbol for a blank is considered to consider the RF transmission / reception switching time delay, but one or more OFDM symbols for a blank may be considered according to the value of the timing adjustment related variable.

&Lt; Fourth Embodiment &gt;

FIG. 12 is a diagram illustrating a downlink subframe structure of an L3 relay system for a downlink backhaul according to a fourth embodiment of the present invention. Referring to FIG. The fourth embodiment contemplates a structure for transmitting the PDCCH and the PDSCH 1204 of the downlink backhaul together in the conventional PDSCH region in the downlink backhaul subframe, unlike the third embodiment. That is, only the PDCCHs of the UEs belonging to the base station are transmitted in the conventional PDCCH region 1202 in the downlink backhaul subframe, and the PDCCH related to the downlink backhaul is allocated to the PDSCH region by Time Division Multiplexing (TDM) and Frequency Division Multiplexing May be joint-coded and mapped to the PDSCH region and transmitted. For such a structure, the base station must inform the relay node of the downlink backhaul resource area through an upper signal.

12, a relay node transmits a PDCCH 1212 to terminals belonging to a relay node immediately before receiving a downlink backhaul subframe from a base station, and the base station transmits a PDCCH 1212 belonging to a base station cell The PDCCH 1202 and the PDSCH 1203 of the UEs can be divided and transmitted by frequency division multiplexing. This structure is to maintain compatibility with the conventional LTE system.

In the fourth embodiment, too, the RF transmission / reception switching time delay occurs in the immediately preceding reception 1206 and the immediately following reception 1207 of the downlink backhaul resource, and in consideration of this in the backhaul subframe, the base station transmits the last OFDM symbol . In the fourth embodiment, since the relay node does not need to receive the PDCCH 1202 from the base station unlike the third embodiment, the reception start timing of the relay node becomes the PDSCH start timing of the downlink backhaul subframe. Therefore, since it is not necessary to consider the blank of N OFDM symbols generated in the third embodiment, FIG. 12 shows only the RF transmission / reception switching time delay considering the last OFDM symbol which should be left blank in the base station. The corresponding blank resource is applied to the last OFDM symbols 1205 of the backhaul RB resource in the downlink backhaul subframe.

The relay node can adjust the transmission timing with the terminal belonging to the relay node cell as shown in FIG. 12 based on the reception timing of the downlink backhaul subframe from the base station.

The base station transmission procedure according to the fourth embodiment maps the PDCCH and the PDSCH of the downlink backhaul to transmission in the conventional PDSCH region in step 1001 of FIG. 10, and uses only the last OFDM symbol for the blank in steps 1003 and 1004 If it is applied, it can be implemented.

11, the PDCCH of the downlink backhaul is obtained from resources allocated in advance for the downlink backhaul, i.e., the conventional PDSCH region, and only the last OFDM symbol is received in step 1102 It can be implemented if it is used for blank.

In the fourth embodiment, one OFDM symbol for a blank is considered as an RF transmission / reception switching time delay, but one or more OFDM symbols for a blank may be considered according to a value of a timing adjustment related variable.

<Fifth Embodiment>

13 is a diagram illustrating an uplink subframe structure of an L3 relay system for an uplink backhaul according to a fifth embodiment of the present invention. Particularly, the fifth embodiment considers the case where the SRS transmission is allowed in the uplink backhaul subframe as in the first embodiment. The SRS is used to adjust the transmission timing of the relay node, and the channel state information for the frequency domain of the wireless backhaul link obtained by the base station via the SRS is used for scheduling wireless backhaul resources.

Referring to FIGS. 5 and 13, in the first embodiment, the uplink backhaul subframe 501 is retransmitted by delaying the transmission timing of the UL link, which is the timing at which the UE transmits to the relay node, The switching time delay is considered in the first SC-FDMA symbol interval 502 of FIG. On the other hand, in order to consider not only the RF transmission / reception switching time delay, but also the change of the transmission timing of the uplink backhaul subframe according to the change of the reception timing of the downlink backhaul subframe, the fifth embodiment transmits the first and second SC- To give up.

If it is possible to move the position of the RS symbol in the uplink sub-frame structure, in order to reduce the channel estimation error in the PUSCH 1309 positioned from the third RS-FDMA subframe structure, five RS symbols located in the fourth SC- Th SC-FDMA symbol 1307 in order to minimize the power consumption.

In the period of the uplink backhaul subframe 1301 transmitted by the relay node RN to the base station eNB, because the relay node can not receive the signal, the uplink resource 1304 is transmitted to the UEs belonging to the relay node cell Do not assign. In the interval other than the uplink backhaul subframe, the relay node performs a reception operation during the interval between the uplink subframes 1305 and 1306 of the terminals belonging to the relay node cell.

Also, the synchronization of the uplink sub-frame of the uplink of the relay node coincides with the synchronization of the uplink sub-frame of the UEs belonging to the base station cell. Therefore, the SRS 1303 in the uplink backhaul subframe must be located in the last SC-FDMA symbol, which is the same as the conventional one, in order to maintain the orthogonality with the SRS transmission of the UEs belonging to the base station cell.

Uplink resources of UEs belonging to the relay node cell can be frequency-division multiplexed and transmitted in the PUSCH 1310 area of the UL access sub-frames 1305 and 1306, and the PUSCH 1309 of the UL sub- The uplink backhaul resource of the relay node and the uplink resources of the UEs belonging to the base station cell can be frequency-division multiplexed and transmitted.

On the other hand, switching from RF reception to RF transmission is required immediately before the uplink backhaul subframe, and switching from RF transmission to RF reception is required immediately after the uplink backhaul subframe. The resulting RF transmission / reception switching time delay should be considered in the uplink backhaul subframe 1301. In addition, the transmission timing of the uplink backhaul subframe may change according to the reception timing of the downlink backhaul subframe. Therefore, the timing change should be additionally considered.

In the case of the fifth embodiment, the RF transmission / reception switching time delay and the transmission timing change of the uplink backhaul subframe due to the reception timing change of the downlink backhaul subframe are considered while maintaining the proposed subframe structure. That is, the relay node waits for transmission of the first and second SC-FDMA symbols 1302 and forwards the transmission timing of the UL link, which is the timing at which the UE transmits to the relay node, behind one SC-FDMA symbol A change in the transmission timing of the uplink backhaul subframe according to the switching time delay and the reception timing change of the downlink backhaul subframe in the first and second SC-FDMA symbol periods 1302 of the uplink backhaul subframe 1301 are considered .

14 is a block diagram of a transmitting apparatus for an uplink backhaul of a relay node according to the present invention.

Referring to FIG. 14, the SRS symbol generator 1401, the RS symbol generator 1402, and the PUSCH symbol generator 1403 of the relay node transmitter generate SRS, RS, and PUSCH symbols, respectively. The generated SRS symbol and RS symbol are directly input to the subcarrier symbol mapper 1405 of 1405 and the PUSCH symbol is input to the subcarrier symbol mapper 1405 via the FFT unit 1404. [ The output of the subcarrier symbol mapper 1405 is mapped to the input of the IFFT device 1406. At this time, the uplink physical channel symbol generation and mapping controller 1300 controls the PUSCH symbol generator 1403 to perform rate matching in consideration of an SC-FDMA symbol for a blank, and to perform rate matching in a subcarrier symbol mapper 1405, FDMA symbol to be precisely mapped to the generated PUSCH symbol. In the case of the SRS symbol generator 1401, it may not be used depending on the structure of the uplink backhaul subframe.

15 is a block diagram of a receiving apparatus for an uplink backhaul of a base station according to the present invention.

Referring to FIG. 15, the FFT unit 1500 performs Fourier transform of a received uplink SC-FDMA signal and outputs each subcarrier received symbols. The received symbols are divided into PUSCH, RS, and SRS symbols by a subcarrier symbol demapper 1501. The RS symbols are input to an RS symbol-based channel information generator 1505, and PUSCH symbol related channel state information is notified to a channel compensator 1507 to perform channel compensation of a PUSCH symbol received from a subcarrier symbol demapper.

The channel compensated PUSCH symbol is converted to a data symbol that can be decoded and decoded by the IFFT unit 1503 and is applied to the PUSCH symbol decoder 1504. The SRS symbol-based channel information generator 1506 receives the SRS symbols from the subcarrier symbol demapper 1501 and generates channel information. This channel information is used when the BS schedules uplink backhaul resources.

The uplink physical channel symbol decoding and de-mapping controller 1502 demaps the PUSCH considering the SC-FDMA symbols for the blank when de-mapping PUSCH, RS, and SRS from the sub-carrier symbol demapper 1501. The uplink physical channel symbol decoding and demapping controller 1502 controls operations of the PUSCH symbol decoder 1504, the RS symbol based channel information generator 1505, and the SRS symbol based channel information generator 1506. In the case of the channel information generator 1506 based on the SRS symbol, it may not be used depending on the structure of the uplink backhaul subframe.

16 is a block diagram of a transmitting apparatus for a downlink backhaul of a base station according to the present invention.

Referring to FIG. 16, RS subcarrier symbol generator 1601, PDCCH subcarrier symbol generator 1602 and PUSCH subcarrier symbol generator 1603 of the base station transmitter generate subcarrier symbols of RS, PDCCH, and PDSCH channels, respectively. The generated symbols are mapped through a subcarrier symbol mapper 1604 so that they are mapped to an appropriate IFFT unit 1605 input according to a subcarrier.

The downlink physical channel symbol generation and mapping controller 1600 allows the subcarrier symbol mapper 1604 to correctly map the symbols of the channels in the corresponding subframe. The downlink physical channel symbol generation and mapping controller 1600 controls the PDSCH subcarrier symbol generator 1603 to perform rate matching of data in consideration of the OFDM symbols for the blank and provides the OFDM symbols for blanking to the subcarrier symbol mapper 1604. [ To be mapped in consideration of symbols. In a structure in which a PDCCH transmitted from a downlink backhaul subframe to a relay node is transmitted to a PDSCH region, a downlink physical channel symbol generation and mapping controller 1600 controls a subcarrier symbol mapper 1604 to transmit a PDCCH and a PDSCH And controls the PDSCH subcarrier symbol generator 1603 to perform joint coding of the PDCCH and the PDSCH, and then controls the subcarrier symbol mapper 1604 to map the combined coded symbol to the PDSCH region. can do.

17 is a block diagram of a receiving apparatus for a downlink backhaul of a relay node according to the present invention.

17, the FFT unit 1700 performs Fourier transform on the received downlink OFDM signal to output the respective subcarrier received symbols, and the received symbols are demodulated by the subcarrier symbol demapper 1701 to the PDSCH, the PDCCH, and the RS Symbols.

The RS symbol is input to a channel information generator 1703 based on RS subcarriers and notifies PDSCH and PDCCH symbol related channel state information to a PDSCH subcarrier symbol decoder 1705 and a PDCCH subcarrier symbol decoder 1704, And performs decoding of the PDSCH and the PDCCH received from the mapper 1701.

The downlink physical channel symbol decoding and demapping controller 1702 demaps the PDSCH considering the OFDM symbols for the blank when demapping the PDSCH, PDCCH, and RS in the subcarrier symbol demapper 1701. The downlink physical channel symbol decoding and demapping controller 1702 demaps the PDSCH, The decoder 1705, the PDCCH subcarrier symbol decoder 1704, and the channel information generator 1703. In a structure in which a PDCCH transmitted from a downlink backhaul subframe to a relay node is mapped to a PDSCH region, a downlink physical channel symbol decoding and demapping controller 1702 controls a subcarrier symbol demapper 1701 to add a PDCCH And when the PDCCH and the PDSCH are joint-coded in the PDSCH region, the sub-carrier symbol demapper 1701 is controlled to demap the combined coded symbol to the PDSCH, and then the PDSCH sub- (1705) to decode the joint coded symbol.

It should be noted that the embodiments of the present invention disclosed in the present specification and drawings are only illustrative examples of the present invention and are not intended to limit the scope of the present invention in order to facilitate understanding of the present invention. It will be apparent to those skilled in the art that other modifications based on the technical idea of the present invention are possible in addition to the embodiments disclosed herein.

1 is a block diagram showing a structure and a slot structure of an SC-FDMA transmitter;

BACKGROUND OF THE INVENTION 1. Field of the Invention [0002] The present invention relates to an uplink frame structure for an uplink and an OFDM based on SC-FDMA of an EUTRA, which is a 3GPP next generation mobile communication technology standard.

3 is a diagram illustrating a resource allocation structure for uplink control channel and data channel transmission based on SC-FDMA in an LTE (Long Term Evolution) system.

4 is a diagram illustrating a resource allocation structure for OFDM-based downlink control channel and data channel transmission in an LTE system;

5 is a diagram illustrating an uplink subframe structure of an L3 relay system for an uplink backhaul according to a first embodiment of the present invention.

6 is a flowchart illustrating a procedure of transmitting a relay node for an uplink backhaul in an L3 relay system according to the first embodiment of the present invention.

FIG. 7 is a flowchart illustrating a reception procedure of a base station for uplink backhaul in a wireless communication L3 relay system according to the first embodiment of the present invention; FIG.

FIG. 8 is a diagram illustrating an uplink subframe structure of an L3 relay system for an uplink backhaul according to a second embodiment of the present invention; FIG.

9 is a diagram illustrating a downlink subframe structure of an L3 relay system for a downlink backhaul according to a third embodiment of the present invention.

10 is a flowchart illustrating a transmission procedure of a base station for a downlink backhaul in an L3 relay system according to a third embodiment of the present invention.

11 is a flowchart showing a procedure of receiving a relay node for a downlink backhaul in an L3 relay system according to a third embodiment of the present invention.

FIG. 12 illustrates a downlink subframe structure of an L3 relay system for a downlink backhaul according to a fourth embodiment of the present invention; FIG.

13 is a diagram illustrating an uplink subframe structure of an L3 relay system for an uplink backhaul according to a fifth embodiment of the present invention.

FIG. 14 is a block diagram of a transmitting apparatus for an uplink backhaul of a relay node according to the present invention; FIG.

15 is a block diagram of a receiving apparatus for an uplink backhaul of a base station according to the present invention;

16 is a block diagram of a transmitting apparatus for a downlink backhaul of a base station according to the present invention;

17 is a block diagram of a receiving apparatus for a downlink backhaul of a relay node according to the present invention.

Claims (10)

A method for transmitting uplink sub-frames of a relay node in a relay-based wireless communication system, An information obtaining step of obtaining scheduling information for the uplink backhaul subframe from a base station through a downlink backhaul control channel; And at least one predetermined symbol located at a first portion or a last portion of the uplink backhaul subframe through the scheduling information as a symbol for blanking, Data mapping step for rate matching and mapping: Multiplexing one or more symbols of the uplink backhaul subframe; And And transmitting the multiplexed uplink backhaul subframe. The method according to claim 1, And wherein the predetermined symbol comprises two adjacent symbols at the beginning of the uplink backhaul subframe. 3. The method of claim 2, And multiplexing a reference signal (RS) to the fifth and eleventh symbols in the uplink backhaul subframe. A method for receiving uplink backhaul subframes of a base station in a relay-based wireless communication system, Performing scheduling for the uplink backhaul subframe of the relay node; Receiving the scheduled uplink backhaul subframe; Performing demultiplexing on the received uplink backhaul subframe; Mapping is performed for the uplink backhaul subframe using at least one preset symbol located at the beginning or end of the scheduled uplink backhaul subframe as a symbol for blanking step; And And performing decoding of the demapped symbols to obtain uplink backhaul data. 5. The method of claim 4, And wherein the predetermined symbol comprises two adjacent symbols at the beginning of the uplink backhaul subframe. A scheduling step of scheduling a resource for downlink backhaul of a relay node and downlink resources of terminals belonging to a base station cell; And mapping the control symbols of the relay node and the UEs to a PDCCH field on a downlink control channel (PDCCH), and transmitting the data symbols of the scheduled UE to a Physical Downlink Shared Channel (PDSCH) To a first mapping step; Matching the data of the scheduled relay node corresponding to one symbol for switching time delay located at the end of the subframe and the PDSCH region excluding the N symbols used for the PDCCH transmission of the relay node, A second mapping step of mapping symbols to PDSCH regions excluding N + 1 symbols located at the end of the subframe; And And multiplexing the PDCCH, the PDSCH, and the RSs of the MS, the scheduled relay node and the MS, in a relay-based wireless communication system. A plurality of symbol generators for generating a sounding reference signal (SRS), a reference signal (RS), and a physical uplink shared channel (PUSCH) symbols; A Fast Fourier Transform (FFT) unit for receiving the PUSCH symbols and converting the received PUSCH symbols into a frequency band signal; A subcarrier symbol mapper for mapping the SRS symbol, the RS symbol, and the Fourier transformed PUSCH symbols to an allocated resource region; And A symbol generator for generating the PUSCH symbol controls to perform rate matching in consideration of a blank symbol, an uplink physical channel control unit for controlling mapping of the input symbols to an area excluding the blank symbols in the subcarrier symbol mapper, And a symbol generating and mapping controller for relaying the uplink data to the relay node. 8. The method of claim 7, And an inverse Fast Fourier Transform (IFFT) apparatus for converting an output signal of the subcarrier symbol mapper into a time band. The relay-based wireless communication system of claim 1, . A plurality of symbol generators for generating a reference signal (RS) subcarrier symbol, a physical downlink control channel (PDCCH) subcarrier symbol, and a physical downlink shared channel (PDSCH) subcarrier symbol; A subcarrier symbol mapper for receiving the RS subcarrier symbol, the PDCCH subcarrier symbol, and the PDSCH subcarrier symbol and mapping the received subcarrier symbol to the corresponding subframe; And A symbol generator for generating the PDSCH subcarrier symbol controls to perform rate matching of data in consideration of a blank symbol, and the input symbols are mapped to the corresponding subframe in consideration of the blanking symbols in the subcarrier symbol mapper And a downlink physical channel symbol generation and mapping controller for controlling the downlink physical channel symbol allocation and the downlink physical channel symbol allocation. 10. The apparatus of claim 9, wherein the downlink physical channel symbol generation and mapping controller And controls mapping of the PDCCH subcarrier symbol and the PDSCH subcarrier symbol to the PDSCH region when the PDCCH subcarrier symbol is mapped to the PDSCH region of the corresponding subframe. Backhaul transmission resource allocation device.

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