KR20080090707A - Method for signal transmitting and apparatus for the same, method for signal receiving and apparatus for the same - Google Patents

Abstract

A method and an apparatus for transmitting and receiving signals are provided to improve reception performance of a receiver by dispersing input data in a frequency range. An apparatus for transmitting and receiving signals includes a symbol mapper(140), a block selector(150), a pre-coder(160), and an MIMO(Multiple Input Multiple Output) encoder(170). The symbol mapper maps input data into symbol data according to a predetermined transmission scheme. The block selector selects the data which is farther than a coherence bandwidth from the symbol data and outputs the selected data. The pre-coder codes the selected symbol data, so that the symbol data is distributed into at least two symbol data in a frequency region, and outputs the coded result. The MIMO encoder encodes the pre-coded data and transmits the pre-coded data in multiple channels.

Description

Method for signal transmitting and apparatus for the same, Method for signal receiving and apparatus for the same

1 is a block diagram schematically showing an apparatus for transmitting a signal as an embodiment according to the present invention;

2 is a block diagram schematically showing a linear precoding unit according to an embodiment of the present invention.

3 (a) is a diagram illustrating a matrix of codes for distributing input data according to an embodiment of the present invention.

3 (b) is a diagram illustrating another code matrix for distributing input data according to an embodiment of the present invention.

4 is a block diagram schematically illustrating a case in which a signal transmission apparatus has a plurality of transmission paths according to an embodiment of the present invention.

5A to 5E illustrate an example of a 2 × 2 code matrix for distributing input symbols according to an embodiment of the present invention.

6 is a block diagram schematically illustrating an apparatus for receiving a signal according to an embodiment of the present invention.

7 (a) is a block diagram schematically showing an example of a linear precoding decoder as an embodiment according to the present invention.

7 (b) is a block diagram schematically illustrating another example of a linear precoding decoder according to an embodiment of the present invention.

8 is a block diagram schematically illustrating a case in which a signal receiving apparatus has a plurality of receiving paths according to an embodiment of the present invention.

9 (a) to 9 (e) illustrate an example of a 2 × 2 code matrix for reconstructing distributed symbols as an embodiment according to the present invention.

10 is a flowchart illustrating a signal transmission / reception method according to an embodiment of the present invention.

* Explanation of symbols for the main parts of the drawings

100: outer coder 110: outer interleaver

120: inner coder 130: inner interleaver

140: symbol mapper 150: block selection unit

160: linear precoding unit 170: multiple input and output encoder

180: frame forming unit 190: modulator

195: transmission unit

The present invention relates to a signal transmission and reception method and a signal transmission and reception apparatus, and more particularly, to a signal transmission and reception method and a transmission and reception apparatus that is robust to frequency selective fading.

As technology advances, the size of data desired by a user is gradually increasing, but there is a certain limit to the expansion of a transmission resource for transmitting the data to the user. Therefore, various techniques have been developed to improve the transmission efficiency of data using finite transmission resources.

Among the above techniques, there is a multiple input / output (MIMO: Multi Input Multi Output) scheme in which a plurality of transmission / reception antennas are used to increase data transmission efficiency.

In a transmission channel having a long delay, selective fading is experienced in the frequency domain, and the distortion of the magnitude becomes very severe according to the delay spread of the channel. Therefore, the signal-to-noise ratio (SNR) for each transmission band is changed, and the reception rate is reduced for a transmission channel having a very low SNR.

In the multiple input / output scheme, array gain is obtained by using multiple antennas, thereby improving average SNR. In addition, diversity gain may be obtained when fading of a transmission channel from each transmission antenna to each reception antenna is independent.

However, in the case of the multi-input / output method, when only one specific transmission channel is considered, there is still a problem that the frequency selective fading due to the delay time of the channel must be experienced.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a signal transmission / reception method and a transmission / reception apparatus robust to frequency selective fading.

The signal transmission apparatus according to the present invention for solving the above problems, the symbol mapper for mapping the input data to the symbol data according to the transmission scheme, the data farther away from the coherence bandwidth (coherence bandwidth) from the symbol data A block selector for selecting and outputting a signal, a precoding unit for coding and outputting the selected symbol data to be distributed over at least two symbol data in a frequency domain, and a multiple input / output encoder for encoding the precoded data so as to be transmitted in multiplexes It includes.

In a signal transmission method according to the present invention, selecting and outputting data farther than a coherence bandwidth among symbol data mapped according to a corresponding transmission method, and outputting the selected symbol data to at least two symbols in a frequency domain. Coding and outputting the data to be distributed to the data, and performing multiple input / output encoding so that the coded data can be transmitted in multiplex.

The signal receiving apparatus according to the present invention is a multiple input / output decoder for decoding a plurality of received data and outputting one symbol data string, and precoding for restoring and outputting data distributed in a frequency domain from the output symbol data string. A decoder, a block reconstruction unit for returning the recovered symbol data to an original position farther than a coherence bandwidth, and a symbol demapper for demapping the symbol data returned to the original position to output bit data corresponding to the symbol do.

The signal receiving method according to the present invention comprises the steps of outputting one symbol data string by multiple input / output decoding of multiplely received data, decoding the output symbol data, restoring data distributed in a frequency domain, and Returning the recovered symbol data to an original position farther than a coherence bandwidth, and demapping the returned symbol data.

Other objects, features and advantages of the present invention will become apparent from the following detailed description of embodiments taken in conjunction with the accompanying drawings.

In addition, the terms used in the present invention was selected as a general term widely used as possible now, but in certain cases, the term is arbitrarily selected by the applicant, in which case the meaning is described in detail in the corresponding description of the invention, It is to be clear that the present invention is to be understood as the meaning of terms rather than names.

Operation of the signal transmission and reception method and the signal transmission and reception device according to the present invention configured as described above will be described in detail with reference to the accompanying drawings.

1 is a block diagram schematically showing a signal transmission apparatus according to an embodiment according to the present invention. The transmission and reception system uses MIMO (Multi Input Multi Output) for multiple input and output.

The signal transmission apparatus of FIG. 1 may be a signal transmission system for transmitting video data such as a broadcast signal. For example, it may be a signal transmission system according to a digital video broadcasting (DVB) system. An embodiment of a signal transmission system according to the present invention will be described with reference to FIG. 1.

1 illustrates an outer coder 100, an outer interleaver 110, an inner coder 120, an inner interleaver 130, and a symbol mapper. mapper 140, block selector 150, linear precoder 160, multiple input / output encoder 170, frame builder 180, modulator 190, and transmitter 195. It includes. 1 illustrates a process of processing a signal in the signal transmission system.

The outer coder 100 and the outer interleaver 110 may encode and interleave input data in order to improve transmission performance of the input signal. For example, in the case of DVB-T, a Reed-Solomon coded method may be used as an outer coding method, and a convolution interleaving method may be performed as an interleaving method.

The inner coder 120 and the inner interleaver 130 perform interleaving by recoding a signal to be transmitted in preparation for an error in the transmission signal. The inner coder 120 may encode a transmission signal according to a punctured convolution code. The inner interleaving method of the inner interleaver 130 may be native or in-depth depending on memory operations of transmission modes of 2k, 4k and 8k, for example, in the case of DVB-T. -depth) An interleaving scheme can be used.

The symbol mapper 140 may map a transmission signal to a symbol according to 16QAM, 64QAM, QPSK, etc. in consideration of a pilot signal and a transmission parameter signal according to a transmission mode.

The block selector 150 selects data distant from the coherence bandwidth from the symbol data output from the symbol mapper 140 and transmits the data to the linear precoding unit 160. For example, when the coherence bandwidth is referred to as 'd', data loss in the bandwidth due to deep fading is prevented by selecting and outputting data whose bandwidth is greater than or equal to 'd'. The selection distance may vary depending on implementation.

The linear precoding unit 160 distributes the input symbol data to a plurality of output symbol data, thereby reducing the probability that all information is lost due to fading when experiencing a frequency selective fading channel.

2 is a block diagram schematically showing a linear precoding unit according to an embodiment of the present invention. The precoding unit 160 includes a serial / parallel converter 162, an encoder 164, and a parallel / serial converter 166.

The serial / parallel converter 162 converts the input data into parallel data. The encoding unit 164 distributes the parallel data into a plurality of data through encoding matrixing.

3A is a diagram illustrating a matrix of codes for distributing input data according to an embodiment of the present invention. 3 (a) is called a vanderMonde matrix as an example of an encoding matrix for distributing the input data into a plurality of output data. The input data may be arranged in parallel in the length (L) of the output data.

Θ of the matrix may be expressed by the following equation, and may be defined in other ways. The vanderMonde matrix may adjust its matrix component by Equation 1.

The matrix rotates each input data by the phase of the corresponding Equation 1 and reflects the input data in the output data. Therefore, the input values may be distributed among at least two output values according to the characteristics of the matrix.

In Equation 1, L represents the number of output data. If the input data group input to the encoding unit 164 of FIG. 2 is x and the data group coded and output from the encoding unit 164 by the matrix is y, y is represented by the following equation (2).

3 (b) is a diagram illustrating another code matrix for distributing input data according to an embodiment of the present invention. 3 (b) is called an Hadamard matrix as an example of an encoding matrix for distributing the input data into a plurality of output data. The matrix of FIG. 3 (b) is a general form extended to a size of any L = 2 ^k , and 'L' represents the number of output symbols to distribute each input symbol.

The output symbols of the matrix can be obtained by the sum and difference of the L input symbols. In other words, each input symbol can be spread over L output symbols.

Also in the case of the matrix of FIG. 3B, the input data group input to the encoding unit 164 of FIG. 2 is x, and the data group coded and output from the encoding unit 164 by the matrix is y. Y is the product of the matrix and x.

The parallel / serial converter 166 converts the data received by the encoder 164 back into serial data and outputs the serial data.

The multiple input / output encoder 170 encodes the data precoded by the linear precoding unit 160 to be carried on a plurality of transmission antennas.

There are two types of multiple input / output encoding methods, spatial multiplexing and spatial diversity. Spatial multiplexing is a method in which multiple antennas are transmitted to a transmitter and a receiver to transmit different data at the same time, thereby transmitting data at higher speed without further increasing the bandwidth of the system. Spatial diversity is a method of obtaining transmit diversity by transmitting data of the same information from multiple transmit antennas.

In this case, as the multiple diversity input / output encoder 170 having a spatial diversity scheme, a space-time block code (STBC), a space-frequency block code (SFBC), a space-time trellis code (STTC), or the like may be used. The spatial multiplex multiple input / output encoder 170 simply transmits data streams by separating the number of transmit antennas, and provides full-diversity full-rate (FDFR) code, linear dispersion code (LDC), and V-BLAST. (Vertical-Bell Lab. Layered space-time) and D-BLAST (diagonal-BLAST) can be used.

The frame forming unit 180 forms a frame by inserting a pilot signal in a data section so as to modulate the precoded signal in an orthogonal frequency division multiplex (OFDM) scheme.

For example, in the case of DVB-T, each frame includes 68 OFDM symbols. Each symbol includes 6817 carriers in 8k mode and 1705 carriers in 2k mode. The OFDM frame includes a distributed training signal, a continuous training signal and a transmission parameter signal (TPS) carrier, respectively. The modulator 190 inserts and modulates a guard interval so that the data output from the frame former 180 can be carried on subcarriers of OFDM.

The transmitter 195 converts a digital signal having a guard period and a data period output from the modulator 190 into an analog signal and transmits the signal.

4 is a block diagram schematically illustrating a case in which a signal transmission apparatus has a plurality of transmission paths according to an embodiment of the present invention. For convenience of explanation, the following description will be given by using two transmission paths as an example.

4 illustrates an outer coder 400, an outer interleaver 410, an inner coder 420, an inner interleaver 430, and a symbol mapper. mapper 440, block selector 450, linear precoding unit 460, multiple input / output encoder 470, first frame builder 480, second frame former 485, A first modulator 490, a second modulator 491, a first transmitter 495 and a second transmitter 496 are included.

Signal processing from the outer coder 400 to the multiple input / output encoder 470 is the same as described with reference to FIG. 1. The linear precoding unit 460 includes a serial / parallel converter, an encoder, and a parallel / serial converter.

5A to 5E illustrate an example of a 2 × 2 code matrix for distributing input symbols according to an embodiment of the present invention. The code matrixes of FIGS. 5A to 5E may be applied to the transmitting apparatus as shown in FIG. 4, and two data input to the encoding unit of the linear precoding unit 460 are distributed to two output data. Let's do it.

The matrix of FIG. 5A is an embodiment of the vanderMonde matrix described with reference to FIG. 3A.

) 회전된 두번째 입력 데이터를 더하여 첫번째 출력 데이터로 출력 하며, 첫번째 입력 데이터와 위상이 225도(

) 회전된 두번째 입력 데이터를 더하여 두번째 출력 데이터로 출력한다. 그리고 상기 각 출력 데이터는

로 나누어 스케일링(scaling)한다.The matrix of FIG. 5 (a) is 45 degrees out of phase with the first input data.

) Add the rotated second input data and output it as the first output data. The phase is 225 degrees with the first input data.

) Add the rotated second input data and output it as the second output data. And each output data

Scaling by dividing by.

The matrix of FIG. 5 (b) is an embodiment of the Hadamard matrix described in FIG. 3 (b).

로 나누어 스케일링(scaling)한다.The matrix of FIG. 5 (b) adds the first input data and the second input data among the two input data and outputs the first output data. The second input data is subtracted from the first input data and output as the second output data. And each output data

Scaling by dividing by.

FIG. 5C is a diagram illustrating another example of a code matrix for distributing an input symbol applicable to FIG. 4 according to an embodiment of the present invention. The matrix of FIG. 5C is an embodiment of another code other than the matrix described with reference to FIGS. 3A and 3B.

) 회전된 첫번째 입력 데이터와 위상이 -45도(

) 회전된 두번째 입력 데이터를 더하여 첫번째 출력 데이터로 출력하며, 위상이 45도 회전된 첫번째 입력 데이터에서 위상이 -45도 회전된 두번째 입력 데이터를 빼서 두번째 출력 데이터로 출력한다. 그리고 상기 각 출력 데이터는

로 나누어 스케일링한다.In the matrix of FIG. 5C, the phase of the two input data is 45 degrees (

) The first input data rotated and the phase is -45 degrees (

The second input data rotated is added to the first output data, and the second input data rotated by -45 degrees is subtracted from the first input data rotated by 45 degrees to output the second output data. And each output data

Divide by to scale.

FIG. 5 (d) is a diagram illustrating another example of a code matrix for distributing input symbols applicable to FIG. 4 according to an embodiment of the present invention. The matrix of FIG. 5D is another embodiment of the code other than the matrix described with reference to FIGS. 3A and 3B.

로 나누어 스케일링한다.The matrix of FIG. 5 (d) adds the first input data multiplied by 0.5 to the second input data and outputs the first output data, and subtracts the second input data multiplied by 0.5 from the first input data and outputs the second output data. And each output data

Divide by to scale.

FIG. 5E illustrates another example of a code matrix for distributing input symbols applicable to FIG. 4 according to an embodiment of the present invention. The matrix of FIG. 5E is another embodiment of the code other than the matrix described with reference to FIGS. 3A and 3B. '*' In FIG. 5 (e) means a complex conjugate with respect to input data.

) 회전된 첫번째 입력 데이터와 두번째 입력 데이터를 더하여 첫번째 출력 데이터로 출력 하며, 첫번째 입력 데이터의 켤레 복소수와 위상이 -90(

)도 회전된 두번째 입력 데이터의 켤레 복소수를 더하여 두번째 출력 데이터로 출력한다. 그리고 상기 각 출력 데이터는

로 나누어 스케일링한다.The matrix of FIG. 5E has a phase of 90 degrees between two input data.

The first input data rotated and the second input data are added together to output the first output data. The complex number and phase of the first input data are -90 (

) Also outputs the second output data by adding the complex conjugate of the rotated second input data. And each output data

Divide by to scale.

The precoded data is output to the multiple input / output encoder 470, and the multiple input / output encoder 470 encodes and outputs the input symbol data to be carried on a plurality of transmission antennas. For example, when there are two transmission paths, the multiple input / output encoder 470 outputs precoded data to the first frame forming unit 480 or the second frame forming unit 485.

In the case of the spatial diversity method, data of the same information is output to the first frame forming unit 480 and the second frame forming unit 485, respectively, and when encoded in the spatial multiplexing method, the first frame forming unit ( Different data is output to the 480 and the second frame forming unit 485, respectively.

The first frame forming unit 480 and the second frame forming unit 485 form a frame in which a pilot signal is inserted in a data section so as to modulate each of the received signals by an orthogonal frequency division multiplex (OFDM) scheme.

The first modulator 490 and the second modulator 491 respectively load data output from the first frame former 480 and the second frame former 485 to subcarriers of OFDM. Modulate for transmission.

The first transmitter 495 and the second transmitter 496 respectively convert a digital signal having a guard interval and a data interval output from the first modulator 490 and the second modulator 491 into analog signals. Convert, and transmit the converted analog signal.

6 is a block diagram schematically illustrating an apparatus for receiving a signal according to an embodiment of the present invention. 6 may be included in a DVB receiver or the like.

The embodiment according to the present invention of FIG. 6 includes a receiver 600, a synchronizer 610, a demodulator 620, a frame parsing unit 630, a multiple input / output decoder 640, a linear precoding decoder 650. ), Block decompressor 660, symbol demapper 670, inner deinterleaver 680, inner decoder 690, outer deinterleaver 695, and outer decoder (outer decoder) 697. 6 illustrates a process of processing a signal in the signal receiving system.

The receiver 600 down-converts the frequency band of the received RF signal and converts the frequency band into a digital signal. The synchronizer 610 obtains and outputs a synchronization between a frequency domain and a time domain of the received signal output from the receiver 600. The synchronization unit 610 may use an offset result of the frequency domain of the data output by the demodulator 620 to obtain synchronization of the frequency domain signal.

The demodulator 620 demodulates the received data output from the synchronizer 610 and removes the guard interval. To this end, the demodulator 620 converts the received data into the frequency domain, and decodes the data values distributed in the subcarriers into values assigned to each subcarrier.

The frame parser 630 may output symbol data of a data period excluding a pilot signal according to the frame structure of the signal demodulated by the demodulator 620.

The multiple input / output decoder 640 receives and decodes the data output from the frame parser 630 and outputs one data string. The multiple input / output decoder 640 outputs one data string by decoding according to a scheme corresponding to a scheme encoded by the multiple input / output encoder 170 of FIG.

Linear precoding decoder 650 recovers the original data from the distributed data to be robust to frequency selective fading. The linear precoding decoder 650 restores data by performing an inverse process of distributing data in the signal transmission apparatus.

7A is a block diagram schematically illustrating an example of a linear precoding decoder according to an embodiment of the present invention. The linear precoding decoder 650 includes a serial / parallel converter 652, a first decoder 654, and a parallel / serial converter 656.

The serial / parallel converter 652 converts the input data into parallel data. The first decoding unit 654 restores the original data from the data distributed through decoding matrixing of the parallel data. The decoding matrix performing the decoding becomes an inverse matrix of the encoding matrix of the signal transmission apparatus. For example, when the signal transmission apparatus encodes using the vanderMonde matrix as shown in FIG. 2, the first decoder 654 restores the distributed data to the original data using the inverse matrix of the vanderMonde matrix. .

The parallel / serial converter 656 converts the parallel data received by the first decoder 654 back into serial data and outputs the serial data.

FIG. 7B is a block diagram schematically showing another example of a linear precoding decoder according to an embodiment of the present invention. The linear precoding decoder 650 includes a serial / parallel converter 651, a second decoder 653, and a parallel / serial converter 655.

The serial / parallel converter 651 converts the input data into parallel data, and the parallel / serial converter 655 serializes the parallel data received by the second decoder 653 again. Convert it to data and output it. The second decoding unit 653 restores and outputs original data distributed in parallel data output from the serial / parallel conversion unit 651 by using ML (Maximum Likelihood) decoding.

The second decoding unit 653 is an ML decoder considering a transmission scheme in a transmitter. The second decoding unit 653 restores original data distributed in the parallel data by ML decoding the received symbol data to correspond to the transmission scheme. That is, the ML decoder decodes the received symbol data in consideration of an encoding rule at the transmitting end.

The block reconstruction unit 660 returns the input data to its original position far away from the coherence bandwidth. That is, the block reconstruction unit 660 performs the reverse process of selecting and outputting data farther than the coherence bandwidth from the block selection unit of the signal transmission apparatus to return the data to the original position.

The symbol demapper 670 may restore the symbol data decoded by the linear precoding decoder 650 into a bit string.

An inner deinterleaver 680 performs an inverse process of interleaving on an interleaved data string, and an inner decoder 690 may decode the deinterleaved data to correct an error included in the data. have. The outer deinterleaver 695 and the outer decoder 697 again perform deinterleaving and error correction decoding to output the deinterleaver.

8 is a block diagram schematically illustrating a case where a signal receiving apparatus has a plurality of receiving paths according to an embodiment of the present invention. For convenience of explanation, the following description will be given by using two reception paths as an example.

8, the first receiver 800, the second receiver 805, the first synchronizer 810, the second synchronizer 815, the first demodulator 820, and the second receiver 810 are provided. Demodulator 825, first frame parser 830, second frame parser 835, multiple input / output decoder 840, linear precoding decoder 850, block reconstruction unit 860, symbol demapper ( 870, an inner deinterleaver 880, an inner decoder 890, an outer deinterleaver 895, and an outer decoder 897.

The first receiver 800 and the second receiver 805 each receive an RF signal, down-convert the frequency band, and convert the digital signal into a digital signal. The first synchronizer 810 and the second synchronizer 815 obtain and synchronize the frequency domain and the time domain of the received signal output from the first receiver 800 and the second receiver 805, respectively. The first synchronization unit 810 and the second synchronization unit 815 are offsets of the frequency domain of the data output from the first demodulator 820 and the second demodulator 825, respectively, in order to obtain synchronization of the frequency domain signals. (offset) results are available.

The first demodulator 820 demodulates the received data output from the first synchronizer 810. To this end, the first demodulator 820 converts the received data into the frequency domain, and decodes the data values distributed in the subcarriers into values assigned to each subcarrier. The second demodulator 825 demodulates the received data output from the second synchronizer 815.

Each of the first frame parser 830 and the second frame parser 835 includes a data section excluding a pilot signal according to a frame structure of a signal demodulated by the first demodulator 820 and the second demodulator 825, respectively. Symbol data can be output.

The multiple input / output decoder 840 receives and decodes the data output from the first frame parser 830 and the second frame parser 835, respectively, and outputs one data string. Hereinafter, the signal processing from the multiple input / output decoder 840 to the outer decoder 897 is the same as described with reference to FIG. 6. The linear precoding decoder 850 includes a serial / parallel converter, a first or second decoder, and a parallel / serial converter.

9 (a) to 9 (e) illustrate an example of a 2 × 2 code matrix for reconstructing distributed symbols according to an embodiment of the present invention. The code matrixes of FIGS. 9 (a) to 9 (e) may be applied to a receiving apparatus as shown in FIG. 8 and recover data distributed to two data input to a decoding unit of the linear precoding decoder 850. And print it out.

The matrix of FIG. 9 (a) is an embodiment of the vanderMonde inverse matrix and is a decoding matrix corresponding to the encoding matrix of FIG. 5 (a).

) 회전된 첫번째 입력 데이터와 위상이 -225도(

) 회전된 두번째 입력 데이터를 더하여 두번째 출력 데이터로 출력한다. 그리고 상기 각 출력 데이터는

로 나누어 스케일링(scaling)한다.The matrix of FIG. 9 (a) adds the first input data and the second input data among the two input data and outputs the first output data, and has a phase of −45 degrees (

) The first input data rotated and the phase is -225 degrees (

) Add the rotated second input data and output it as the second output data. And each output data

Scaling by dividing by.

The matrix of FIG. 9 (b) is an embodiment of the Hadamard inverse matrix and is a decoding matrix corresponding to the encoding matrix of FIG. 5 (b).

로 나누어 스케일링(scaling)한다.The matrix of FIG. 9 (b) adds first input data and second input data among two input data and outputs the first output data, and subtracts the second input data from the first input data and outputs the second output data. And each output data

Scaling by dividing by.

FIG. 9 (c) is a diagram illustrating another example of a code matrix for restoring distributed data applicable to FIG. 8 according to an embodiment of the present invention. The matrix of FIG. 9 (c) is a decoding matrix corresponding to the encoding matrix of FIG. 5 (c).

) 회전된 첫번째 입력 데이터와 위상이 -45도(

) 회전된 두번째 입력 데이터를 더하여 첫번째 출력 데이터로 출력하며, 위상이 45도 회전된 첫번째 입력 데이터에서 위상이 45도 회전된 두번째 입력 데이터를 빼서 두번째 출력 데이터로 출력한다. 그리고 상기 각 출력 데이터는

로 나누어 스케일링한다.9 (c) has a phase of -45 degrees between two input data.

) The first input data rotated and the phase is -45 degrees (

The second input data rotated is added to the first output data, and the second input data rotated by 45 degrees is subtracted from the first input data rotated by 45 degrees to output the second output data. And each output data

Divide by to scale.

FIG. 9 (d) is a diagram illustrating another example of a code matrix for restoring distributed data applicable to FIG. 8 according to an embodiment of the present invention. The matrix of FIG. 9 (d) is a decoding matrix corresponding to the encoding matrix of FIG. 5 (d).

로 나누어 스케일링한다.The matrix of FIG. 9 (d) adds first input data multiplied by 0.5 to second input data and outputs the first output data, and subtracts second input data multiplied by 0.5 from the first input data and outputs the second output data. And each output data

Divide by to scale.

FIG. 9E is a diagram illustrating another example of a code matrix for restoring distributed data applicable to FIG. 8 according to an embodiment of the present invention. The matrix of FIG. 9 (e) is a decoding matrix corresponding to the encoding matrix of FIG. 5 (e). '*' In FIG. 9 (e) denotes a complex conjugate with respect to input data.

) 회전된 첫번째 입력 데이터와 두번째 입력 데이터의 켤레 복소수를 더하여 첫번째 출력 데이터로 출력하며, 첫번째 입력 데이터와 위상이 -90도(

) 회전된 두번째 입력 데이터의 켤레 복소수를 더하여 두번째 출력 데이터로 출력한다. 그리고 상기 각 출력 데이터는

로 나누어 스케일링한다.The matrix of FIG. 9 (e) has a phase of −90 degrees (

The first input data is rotated and the complex of the second input data is added to output the first output data. The first input data and the phase are -90 degrees (

) Adds the complex conjugate of the rotated second input data and outputs it as the second output data. And each output data

Divide by to scale.

10 is a flowchart illustrating a signal transmission / reception method according to an embodiment of the present invention.

The signal transmission apparatus selects a transmission symbol farther than the coherence bandwidth of the channel among the mapped symbol data (S1000) to reduce the probability of data loss within the bandwidth due to deep fading.

Precoding is performed to distribute the selected symbol data to a plurality of output symbols (S1010), so that the transmission data is robust to frequency selective fading.

The pre-coded data is multi-input / output encoded so that a plurality of antennas can be transmitted (S1020). The number of antennas can be the number of possible data transmission paths. In the case of the spatial diversity method, data of the same information is transmitted in each path, and in the case of the spatial multiplexing method, different data is transmitted in each path.

In operation S1030, the encoded data is converted into a transmission frame, modulated, and transmitted according to the number of the multi-input / output transmission paths.

The signal receiving apparatus receives the transmitted signal using the plurality of receiving antennas, and demodulates the received signal into data frames (S1040).

The demodulated data frame is parsed and decoded according to a scheme corresponding to a multiple input / output encoded scheme to obtain one symbol data string (S1050).

The output data stream is decoded in the inverse of the method precoded by the transmitting apparatus to restore original data distributed in a plurality of symbol data (S1060).

The recovered symbol data is restored to an original position far away from the coherence bandwidth (S1070). The symbol data may be restored to its original position by performing a reverse process of selecting a transmission symbol in S1000.

The signal transceiving method and the signal transceiving apparatus are not limited to the above examples, and may be applied to all signal transceiving systems to which a multi-input / output method is applied.

The present invention is not limited to the above-described embodiments, and as can be seen in the appended claims, modifications can be made by those skilled in the art to which the invention pertains, and such modifications are within the scope of the present invention.

As described above, according to the signal transmission / reception method and the signal transmission / reception apparatus of the present invention, by distributing input data in the frequency domain, it is robust to frequency selective fading by delay time of each transmission channel, and has an effect of increasing signal reception performance of a receiver. have.

Claims (17)

A symbol mapper for mapping the input data into symbol data according to a corresponding transmission method; A block selector which selects and outputs data farther from a coherence bandwidth in the symbol data; A precoding unit for coding and outputting the selected symbol data to be distributed to at least two symbol data in a frequency domain; And And a multiple input / output encoder for encoding the precoded data to be transmitted in multiplex. The method of claim 1, The precoding unit, A serial / parallel converter for converting input serial data into parallel data; An encoding unit which multiplies the parallel data by an encoding matrix and distributes the parallel data; And And a parallel / serial conversion unit for converting the encoded output parallel data into serial data. The method of claim 2, And the encoding matrix is a vanderMonde matrix. In the vanderMonde matrix Θ, the number of output data is a natural number L and the component θ of the matrix is a natural number k.

If,

. The method of claim 2, And the encoding matrix is a Hadamard matrix. The Hadamard (H _{2 ^ k} ) matrix is a natural number L = 2 ^k when the number of output data,

The method of claim 2, And the encoding matrix is the following matrix when outputting two parallel data to be divided into two data.

The method of claim 2, And the encoding matrix is the following matrix when outputting two parallel data to be divided into two data.

The method of claim 2, And the encoding matrix is the following matrix when outputting two parallel data to be divided into two data. () ^* Is the complex conjugate of the input data.

Selecting and outputting data farther from a coherence bandwidth among symbol data mapped according to the transmission scheme; Coding and outputting the selected symbol data to be distributed to at least two symbol data in a frequency domain; And Multiple input / output encoding so that the coded data can be transmitted in multiplex. A multiple input / output decoder configured to decode multiple received data and output one symbol data string; A precoding decoder configured to recover data distributed in a frequency domain from the output symbol data stream; A block recovery unit for returning the recovered symbol data to an original position farther than a coherence bandwidth; And And a symbol demapper for demapping the symbol data returned to the original position and outputting bit data corresponding to the symbol. The method of claim 9, The precoding decoder, A serial / parallel converter for converting input serial data into parallel data; A first decoding unit multiplying the parallel data by a decoding matrix and restoring data distributed in a frequency domain of the parallel data; And And a parallel / serial converter converting the decoded and restored parallel data into serial data. The method of claim 10, And the decoding matrix is an inverse matrix of a vanderMonde matrix. The method of claim 10, And the decoding matrix is an inverse matrix of a Hadamarde matrix. The method of claim 10, And a decoding matrix is the following matrix when restoring and outputting two pieces of data dispersed in two parallel data inputted.

The method of claim 10, And a decoding matrix is the following matrix when restoring and outputting two pieces of data dispersed in two parallel data inputted.

The method of claim 10, And a decoding matrix is the following matrix when restoring and outputting two pieces of data dispersed in two parallel data inputted.

The method of claim 9, The precoding decoder, A serial / parallel converter for converting input serial data into parallel data; A second decoder for restoring data distributed in a frequency domain by decoding the parallel data according to a transmission scheme; And And a parallel / serial converter converting the decoded and restored parallel data into serial data. Outputting one symbol data string by multiple input / output decoding of multiplely received data; Restoring data distributed in a frequency domain by decoding the output symbol data; And Returning the recovered symbol data to an original position farther than a coherence bandwidth to demap the returned symbol data.

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