KR20080094192A - 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 a signal, and a method and an apparatus for receiving the signal are provided to improve the performance in reception and transmission of the signal in the entire transmission and reception system. A forward error correction encoding operation is performed on data so that a receiver side detects and corrects transmission error(S2300). An interleaving operation is performed on the encoded data, and the interleaved data are mapped to a symbol according to a corresponding transmission and reception system(S2302). A pre-coding process is performed so that the mapped symbol data are dispersed through several output symbols in a frequency region(S2304). The pre-coded symbol data are interleaved and outputted(S2306). The interleaved symbol data are MIMO(Multi-Input Multi-Output)-encoded so that the interleaved symbol data are transmitted through a plurality of antennas(S2308). The encoded data are converted into a transmission frame, according to the number of MIMO transmission paths. Thereafter, the transmission frame is modulated and transmitted(S2310).

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;

Figure 2 (a) is a block diagram schematically showing a forward error correction as an embodiment according to the present invention

2 (b) is a block diagram schematically showing another forward error correction as an embodiment according to the present invention.

3 is a block diagram schematically illustrating a turbo interleaver according to an embodiment of the present invention.

4 illustrates an interleaver for interleaving input data according to an embodiment of the present invention.

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

6 (a) to 6 (c) illustrate a matrix of codes for distributing input data according to an embodiment of the present invention.

7 is a diagram illustrating a structure of a transmission frame according to an embodiment of the present invention.

8 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.

9 (a) to 9 (e) illustrate an example of a 2x2 code matrix for distributing input symbols according to an embodiment of the present invention.

10 is a diagram illustrating an example of an interleaver according to an embodiment of the present invention.

11 is a diagram illustrating a specific example of the interleaver of FIG. 10 according to an embodiment of the present invention.

12 is a diagram illustrating an example of a multiple input / output encoding scheme according to an embodiment of the present invention.

13 (a) is a diagram illustrating the structure of a pilot symbol interval according to an embodiment of the present invention.

13 (b) illustrates another structure of a pilot symbol period according to an embodiment of the present invention.

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

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

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

16 (a) to 16 (c) illustrate an example of a 2x2 code matrix for reconstructing distributed symbols as an embodiment according to the present invention.

17 (a) is a block diagram schematically showing a forward error correction decoding unit as an embodiment according to the present invention;

17 (b) is a block diagram schematically showing another forward error correction decoding unit according to an embodiment of the present invention.

18 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.

19 is a diagram illustrating an example of a multiple input / output decoding scheme according to an embodiment of the present invention.

20 is a diagram illustrating a specific example of FIG. 19 as an embodiment according to the present invention.

21 is a block diagram schematically showing another example of a signal transmission apparatus according to an embodiment of the present invention.

22 is a block diagram schematically showing another example of a signal receiving apparatus according to an embodiment of the present invention.

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

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

* Explanation of symbols for the main parts of the drawings

100: forward error correction 110: the first interleaver

120: symbol mapper 130: linear precoding unit

140: second interleaver 150: multiple input and output encoder

160: frame forming unit 170: modulator

180: 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 transmission and reception apparatus that can increase the data transmission rate.

Users have experienced superiority of HD (High Definition) video and digital sound due to the development of Digital Broadcasting technology, and the better environment is being developed through the continuous development of compression algorithms and high performance of hardware. Will be. The digital television (DTV) may receive the digital broadcast signal and provide various additional services in addition to video and audio to the user.

With the spread of digital broadcasting, demands for better services such as video and audio are increasing, and the size of data desired by the user and the number of broadcasting channels are gradually increasing.

However, it is difficult to cope with the increased data size or the number of broadcast channels using the conventional signal transmission / reception scheme. Accordingly, there is an increasing demand for a new signal transmission / reception technique requiring higher bandwidth efficiency of a channel than a conventional signal transmission / reception scheme and requiring a low cost of configuring a signal transmission / reception network.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a signal transmitting / receiving method and a transmitting / receiving apparatus capable of using an existing signal transmitting / receiving network network and increasing a data transmission rate.

According to an aspect of the present invention, there is provided a signal transmission apparatus comprising: a turbo code encoder for error correction encoding and outputting input data; an interleaver for interleaving the error correction encoded data; and And a symbol mapper for mapping the interleaved data into symbol data according to a corresponding transmission scheme.

In another aspect, an apparatus for transmitting a signal includes a frame forming unit configured to form frame data including a pilot symbol section including pilot carrier information and a data symbol section including input symbol data information, and the frame data comprises orthogonal frequencies. And a transmission unit for converting the modulated data into an analog signal and transmitting the modulation.

In another aspect, an apparatus for transmitting a signal according to the present invention includes a turbo code encoder for encoding input data so as to detect and correct an error of data, an interleaver for interleaving the encoded data, and transmitting the interleaved data correspondingly. A symbol mapper for mapping to symbol data according to a scheme, a fading coding unit for distributing the symbol data in a frequency domain and interleaving and outputting the distributed data, and multiplexing the faded coded output data A multi-input / output encoder for encoding to be transmitted, a frame forming unit for forming frame data consisting of a pilot symbol interval and a data symbol interval, and a modulator for modulating and transmitting the frame data according to an orthogonal frequency multiplexing scheme.

In another aspect, an apparatus for transmitting a signal includes a turbo code encoder for encoding input data to detect and correct an error of data, an interleaver for interleaving the error correction encoded data, and an interleaved data. A symbol mapper for mapping to symbol data according to a transmission scheme, a fading coding unit for distributing the symbol data in a frequency domain, interleaving the distributed data, and outputting the interleaved data and a pilot symbol interval and a data symbol interval And a frame forming unit for forming the configured frame data, and a modulation unit for modulating and transmitting the frame data according to an orthogonal frequency multiplexing scheme.

In accordance with another aspect of the present invention, there is provided a signal transmission method comprising: a turbo code encoding step of encoding input data so as to detect and correct an error of data, interleaving the encoded data, and converting the interleaved data into a corresponding transmission scheme. Mapping to symbol data according to the present invention, fading coding step of distributing the symbol data in a frequency domain, interleaving and outputting the distributed data, and multiple input / output encoding so that the faded coded output data can be transmitted in multiple times. And forming frame data including a pilot symbol period and a data symbol period, and modulating and transmitting the frame data according to an orthogonal frequency multiplexing scheme.

In another aspect, a signal transmission method according to the present invention includes a turbo code encoding step of encoding input data to detect and correct an error of data, interleaving the encoded data, and applying the interleaved data. Mapping to symbol data according to a transmission method, distributing the symbol data in a frequency domain, and fading coding step of interleaving and outputting the distributed data, and forming frame data including a pilot symbol interval and a data symbol interval And modulating and transmitting the frame data according to an orthogonal frequency multiplexing scheme.

A signal receiving apparatus according to the present invention includes a symbol demapper for demapping input symbol data to output bit data corresponding to the symbol, and a deinterleaver for deinterleaving the demapped bit data to restore an order. And a turbo code decoder for error correction decoding the deinterleaved data.

In another aspect, an apparatus for receiving a signal includes a demodulator for demodulating a received signal according to an orthogonal frequency multiplexing scheme, and a frame parser for parsing the demodulated frame data to restore symbol data of a corresponding transmission path. And a multiple input / output decoder for multiplexing and decoding the symbol data and outputting one symbol data string, de-interleaving the output symbol data string, and restoring and outputting data distributed in a frequency domain. A fading decoding unit, a symbol demapper for demapping the recovered and outputted symbol data to output bit data corresponding to the symbol, a deinterleaver for deinterleaving the demapped bit data, and restoring an order; Includes a turbo code decoder that decodes the deinterleaved data to detect and correct errors. The.

In another aspect, an apparatus for receiving a signal includes a demodulator for demodulating a received signal according to an orthogonal frequency multiplexing scheme, a frame parser for parsing the demodulated frame data and restoring transmitted symbol data; A fading decoding unit for de-interleaving the output symbol data, restoring and outputting data distributed in a frequency domain, and bit corresponding to the symbol by demapping the reconstructed output symbol data A symbol demapper for outputting data, a deinterleaver for deinterleaving the de-mapped bit data to restore order, and a turbo code decoder for decoding and detecting errors by decoding the deinterleaved data.

In the signal receiving method according to the present invention, demodulating a received signal according to an orthogonal frequency multiplexing scheme, parsing the demodulated frame data to restore symbol data of a corresponding transmission path, and decoding the symbol data. A multi-input / output decoding step of outputting one symbol data string, a de-interleaving of the output symbol data string, a fading decoding step of restoring and outputting data distributed in a frequency domain, and fading-decoded Demapping symbol data to output bit data corresponding to the symbol, deinterleaving the demapped bit data to restore order, and decoding the deinterleaved data to detect an error; Modifying turbo code decoding.

In another aspect, the signal receiving method according to the present invention comprises the steps of: demodulating a received signal according to an orthogonal frequency multiplexing scheme; parsing the demodulated frame data to restore transmitted symbol data; A fading decoding step of de-interleaving the data, restoring and outputting data distributed in a frequency domain, and outputting bit data corresponding to the symbol by demapping the restored output symbol data And deinterleaving the demapped bit data to restore order, and decoding the deinterleaved data to detect and correct errors in the turbo code.

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 may use 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 a forward error correction (FEC) encoder 100, a first interleaver 110, a symbol mapper 120, and a linear precoding unit 130. , A second interleaver 140, a multiple input / output encoder 150, a frame builder 160, a modulator 170, and a transmitter 180. 1 illustrates a process of processing a signal in the signal transmission system.

The forward error correction unit 100 encodes and outputs an input signal, thereby detecting an error in the transmitted data in the receiver and correcting the error.

2 (a) is a block diagram schematically showing a forward error correction as an embodiment according to the present invention. A turbo code may be used for the forward error correction of FIG. 1. The turbo code encoder is composed of two or more component encoders and a turbo interleaver, and may be divided into a parallel concatenated convolutional code (PCCC) and a serial concatenated convolutional code (SCCC) according to the connection method of the component encoders. . The configuration encoder may use the same type of encoder or may perform double encoding using another type of encoder.

The example of FIG. 2 (a) is a case where a serial encoder (SCCC) code is used as a convolutional encoder. The turbo code encoder includes a first convolutional encoder 102, a turbo interleaver 104, and a second convolutional encoder 106.

The first convolutional encoder 102 convolutionally encodes the inputted data and outputs the data, and the turbo interleaver 104 interleaves the outputted data to shuffle the data. The second convolutional encoder 106 convolutionally encodes the interleaved data and outputs the convolutional encoding. In the above embodiment, dual encoding is performed using a first convolutional encoder and a second convolutional encoder.

2 (b) is a block diagram schematically showing another forward error correction as an embodiment according to the present invention. The example of FIG. 2 (b) is a case of a parallel chain type (PCCC) code, in which all of the constituent encoders use a convolutional encoder. The turbo code encoder includes a third convolutional encoder 101, a turbo interleaver 103, a fourth convolutional encoder 105, and a parallel / serial conversion unit 107.

The third convolutional encoder 101 performs convolutional encoding according to the input data order and outputs the convolutional encoding. The fourth convolutional encoder 105 performs convolutional encoding on the interleaved data interleaved in the turbo interleaver 103 and outputs the convolutional encoding. . The parallel / serial converter 107 outputs one data string by selecting (puncturing) data encoded and output by the third convolutional encoder 101 and the fourth convolutional encoder 105.

3 is a block diagram schematically illustrating a turbo interleaver according to an embodiment of the present invention. In the turbo interleaver used for the turbo code, a block interleaver, a helical interleaver, an odd-even interleaver, a PN interleaver, a random interleaver, an S-random interleaver, a nonuniform interleaver, a Galois Field interleaver, and the like may be used.

The embodiment of FIG. 3 is an interleaver of a block interleaver series, and includes a first LSB selector 300, a lookup table 310, a bit inversion unit 320, a second LSB selector 330, and a rearrangement unit. 340).

It is assumed that the block length of the interleaver is N _turbo and the symbol address is represented by n + 5 bits. When n + 5 bits are counted and input, the n + 5 bits (l _{n +4} , l _{n +3} , l _{n +2} ,…, l ₅ , l ₄ , l ₃ , l ₂ , l ₁ , l ₀ ) Most significant bits (MSB) of n (l _{n +4} , l _{n +3} , l _{n +2} ,…, l ₅ ) are input to the first LSB selector 300, and 5 ( The least significant bits (LSBs) of l ₄ , l ₃ , l ₂ , l ₁ , and l ₀ are input to the lookup table 310 and the bit reversal unit 320.

The first LSB selector 300 adds one bit to the input data bit, and then selects and outputs the n least significant bits. The lookup table 310 outputs pre-stored n bits corresponding to the input 5 bits, and the bit reversing unit 320 outputs the order of the 5 bits inputted (bit-reversed ordered bits).

The second LSB selector 330 multiplies the n bits output from the first LSB selector 300 and the lookup table 310, respectively, and then n least significant bits (t _{n -1} , t _{n -2} , t _{n -3).} ,…, T ₂ , t ₁ , t ₀ )

The rearrangement unit 340 sets 5 bits ( ₀ , l ₁ , l ₂ , l ₃ , l ₄ ) whose order is reversed in the bit inversion unit 320 as the most significant bit, and outputs the second LSB selection unit 330. N bits (t _n-1 , t _n-2 , t _n-3 ,…, t ₂ , t ₁ , t ₀ ) by arranging the least significant bits and then n + 5 bits (l ₀ , l ₁ , l ₂ , l ₃ , l ₄ , t _{n -1} , t _{n -2} , t _{n -3} ,…, t ₂ , t ₁ , t ₀ ). However, the rearrangement unit 340 discards (If, Input ≥ N _turbo ) output values when the input is out of the block length.

The forward error correction encoded data in the forward error correction unit 100 is output to the first interleaver 110. The first interleaver 110 mixes and distributes the data strings output from the forward error correction unit 100 to a random position so as to be robust to a burst error occurring during transmission. The first interleaver 110 may use a convolution interleaver, a block interleaver, and the like, which may vary depending on a transmission system.

4 is a diagram illustrating an interleaver for interleaving input data according to an embodiment of the present invention. 4 is an example of an interleaver that may be used for the first interleaver 110 as a type of block interleaver.

The interleaver of FIG. 4 stores data input in a matrix-type storage space in a predetermined pattern, and reads and outputs data in a pattern different from the storage pattern. For example, the interleaver of FIG. 4 has a storage space (Nr × Nc) consisting of a row of Nr and a column of Nc, and data input to the interleaver is filled from the position of one column, one row of the storage space. Data is stored starting from row 1 of column 1 up to row Nr of column 1, and when the column 1 is filled up, data is stored starting from row 1 of the next column (column 2) up to row Nr. Data can be stored up to Nr rows of Nc columns in the above order.

When reading the data stored in the storage space, the data of the row is read and output from the data of the first row to the first column of the storage space up to the first row Nc column. If all the data of the row is read, starting from the first column of the next lower row (row 2), the data of the row is read and output in the right direction. Data can be read and output up to Nc columns of Nr rows in the same order as described above. At this time, the position of the most significant bit (MSB) of the data block is the upper leftmost, the position of the least significant bit (LSB) is the rightmost lowermost.

A block size, a storage pattern, a read pattern, and the like of the interleaver are one embodiment, and this may vary according to implementation.

The data interleaved by the first interleaver 110 are input to the symbol mapper 120. The symbol mapper 120 may map a transmission signal to a symbol according to a QAM, QPSK, etc. method in consideration of a pilot signal and a transmission parameter signal according to a transmission mode.

The linear precoding unit 130 distributes the input symbol data into 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.

5 is a block diagram schematically showing a linear precoding unit according to an embodiment of the present invention. The precoding unit 130 includes a serial / parallel conversion unit 132, an encoding unit 134, and a parallel / serial conversion unit 136.

The serial / parallel converter 132 converts the input data into parallel data. The encoding unit 134 distributes the parallel data to a plurality of data through encoding matrixing.

The encoding matrix is designed to compare an output symbol with an input symbol so that Pairwise Error Probability (PEP), which is a probability that the two symbols are wrong, is minimized. Designed to minimize PEP, the diversity gain and coding gain obtained through linear precoding can be maximized.

In addition, when the minimum Euclidean distance of a linear precoded symbol is maximized through the encoding matrix, an error probability may be minimized when the receiver uses a maximum likelihood (ML) decoder.

6 (a) is a diagram illustrating a matrix of codes for distributing input data according to an embodiment of the present invention. 6 (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 134 of FIG. 5 is x and the data group coded and output from the encoding unit 134 by the matrix is y, y is represented by Equation 2 below.

6 (b) is a diagram illustrating a matrix of different codes for distributing input data according to an embodiment of the present invention. 6 (b) is called an Hadamard matrix as an example of an encoding matrix for distributing the input data into multiple output data. The matrix of FIG. 6 (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. 6 (b), the input data group input to the encoding unit 134 of FIG. 5 is x, and the data group coded and output from the encoding unit 134 by the matrix is y. Y is the product of the matrix and x.

6 (c) is a diagram illustrating another code matrix for distributing input data according to an embodiment of the present invention. 6 (c) is called Golden code as an example of an encoding matrix for distributing the input data into a plurality of output data. The golden code is a special type of 4x4 matrix, and can be interpreted as two different 2x2 matrices alternately used.

C of FIG. 6C shows a code matrix of a golden code, and x1, x2, x3, and x4 in the code matrix represent symbol data input to the encoding unit 134. FIG. . Each constant in the code matrix determines a characteristic of the code matrix. The values of the rows and columns calculated from the respective constants and input symbol data of the code matrix represent output symbol data. A rule may be defined in the output order of the symbol data according to the implementation example.

The parallel / serial converter 136 converts the data received by the encoder 134 back into serial data and outputs the serial data.

The second interleaver 140 interleaves the symbol data output from the linear precoding unit 130 again. That is, interleaving is performed in the second interleaver 140 so that symbol data dispersed in data output from the linear precoding unit 130 does not experience the same frequency selective fading. A convolution interleaver, a block interleaver, or the like may be used for the second interleaver 140.

The linear precoding unit 130 and the second interleaver 140 process the data to be transmitted to be robust to the frequency selective fading of the channel, and may be viewed as a frequency selective fading coding unit.

The multiple input / output encoder 150 encodes the data interleaved by the second interleaver 140 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, the spatial diversity multiple input / output encoder 150 may use a space-time block code (STBC), a space-frequency block code (SFBC), a space-time trellis code (STTC), or the like. The spatial multiplex multiple input / output encoder 150 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 160 forms a frame by inserting a pilot signal to modulate the precoded signal by an orthogonal frequency division multiplex (OFDM) scheme.

7 is a diagram illustrating a structure of a transmission frame according to an embodiment of the present invention. The transmission frame is composed of a pilot symbol period including pilot carrier information and a data symbol period including only data information.

In FIG. 7, one frame includes M intervals, and is divided into M-1 data symbol intervals and one pilot symbol interval used as a preamble. The frame having the above structure is repeated.

Each symbol period includes carrier information as many as the number of subcarriers of an Orthogonal Frequency Division Multiplex (OFDM) scheme. The pilot carrier information of the pilot symbol interval is composed of random data in order to lower the peak to average power ratio (PAPR). The pilot carrier information has a form in which auto-correlation is an impulse in a frequency domain.

Pilot carrier information is not included in the data symbol interval, and thus data capacity can be increased. For example, in the case of DVB, since the ratio of pilot carriers to total effective carriers is about 10%, the rate of increase of data capacity is expressed by the following equation.

In Equation 3, Δ represents an increase rate, and M is the number of sections included in one frame.

The modulator 170 inserts and modulates a guard interval so that the data output from the frame former 160 can be carried on subcarriers of OFDM. The transmitter 180 converts a digital signal having a guard period and a data period output from the modulator 170 into an analog signal and transmits the signal.

8 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.

9 illustrates a forward error correcting unit 800, a first interleaver 810, a symbol mapper 820, a linear precoding unit 830, a second interleaver 840, and multiplexing. I / O encoder 850, first frame builder 860, second frame builder 865, first modulator 870, second modulator 875, first transmitter 880 and a second transmission unit 885.

Signal processing from the forward error correction 800 to the multiple input / output encoder 850 is the same as described with reference to FIG. 1.

The forward error correcting unit 800 uses a turbo code encoder, and outputs the error correction coded input data. The output data is interleaved in the first interleaver 810 so that the data sequences are mixed. A convolution interleaver, a block interleaver, or the like may be used for the first interleaver 810.

The symbol mapper 820 maps a transmission signal to a symbol according to a QAM, QPSK, etc. method in consideration of a pilot signal and a transmission parameter signal according to a transmission mode. For example, when symbol mapping to 128QAM, 7 bits of data may be included in one symbol, and symbol mapping to 256QAM may include 8 bits of data in one symbol.

The linear precoding unit 830 includes a serial / parallel converter, an encoder, and a parallel / serial converter.

9 (a) to 9 (e) illustrate an example of a 2x2 code matrix for distributing input symbols according to an embodiment of the present invention. The code matrixes of FIGS. 9 (a) to 9 (e) may be applied to the transmission apparatus as shown in FIG. 8, and two data input to the encoding unit of the linear precoding unit 830 are distributed to two output data. Let's do it.

The matrix of FIG. 9 (a) is an embodiment of the vanderMonde matrix described in FIG. 6 (a).

) 회전된 두번째 입력 데이터를 더하여 첫번째 출력 데이터로 출력하며, 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) is 45 degrees out of phase with the first of the two input data.

) Adds the second rotated input data and outputs 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. 9 (b) is an embodiment of the Hadamard matrix described in FIG. 6 (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 distributing an input symbol applicable to FIG. 8 according to an embodiment of the present invention. The matrix of FIG. 9C is an embodiment of another code other than the matrix described with reference to FIGS. 6A, 6B, and 6C.

) 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. 9C, 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. 9 (d) is a diagram illustrating another example of a code matrix for distributing input symbols applicable to FIG. 8 according to an embodiment of the present invention. The matrix of FIG. 9 (d) is another embodiment of code other than the matrix described with reference to FIGS. 6 (a), 6 (b) and 6 (c).

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. 9 (e) is a diagram illustrating another example of a code matrix for distributing input symbols applicable to FIG. 8 according to an embodiment of the present invention. The matrix of FIG. 9 (e) is an embodiment of another code other than the matrix described with reference to FIGS. 6 (a), 6 (b) and 6 (c). '*' In FIG. 9 (e) indicates a complex conjugate with respect to input data.

) 회전된 첫번째 입력 데이터와 두번째 입력 데이터를 더하여 첫번째 출력 데이터로 출력하며, 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. 9 (e) has a phase of 90 degrees between two input data.

) The first input data and the second input data rotated are added 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 second interleaver 840 interleaves the symbol data output from the linear precoding unit 830 again. A convolution interleaver, a block interleaver, or the like may be used for the second interleaver 840. Since the second interleaver 840 serves to mix symbol data dispersed in the data output from the linear precoding unit 830 so as not to experience the same frequency selective fading, the type of the second interleaver 840 is an implementation example of a transmission / reception system. It may vary.

In the case of using the block interleaver, the length of the interleaver may vary depending on implementation. If the length of the interleaver is less than or equal to the OFDM symbol length, interleaving is performed only in an area within one OFDM symbol, and if the length of the interleaver is longer than the OFDM symbol length, interleaving may be performed over several symbols.

10 is a diagram illustrating an example of an interleaver according to an embodiment of the present invention. The interleaver of FIG. 10 may be used in the second interleaver 840 of the transmitting apparatus as shown in FIG. 8 as an embodiment of an interleaver for an OFDM system having a symbol length N.

N represents the length of the interleaver, i has a value equal to the length of the interleaver, that is, an integer value from 0 to N-1. n has the number of effective transport carriers in the transmission system. ∏ (i) denotes a permutation of modulo-N operations, and d _n has values of ∏ (i) in the effective transport carrier region in order except N / 2 values. k represents the index value of the actual transport carrier, so that d / 2 is subtracted from d _n so that the center of the transmission bandwidth is DC. P is a permutation constant and may vary depending on the embodiment.

FIG. 11 is a diagram illustrating a specific example of the interleaver of FIG. 10 as an embodiment according to the present invention. In the example of FIG. 11, the length of an OFDM symbol and the length N of an interleaver are set to 2048, and the number of effective transmission carriers is set to 1536 (1792-256).

Therefore, i is an integer of 0-2047, n is an integer of 0-1535. ∏ (i) is a permutation of modulo-2048 operations, and d _n has a value of ∏ (i) in order except 1024 (N / 2) for a value of 256 ≦ ∏ (i) ≦ 1792. k is a value obtained by subtracting 1024 from d _n . P has 13.

Since the data k corresponding to the input data i is output using the interleaver as described above, the data of the length N of the interleaver can be mixed and transmitted.

The interleaved data is output to the multiple input / output encoder 850, and the multiple input / output encoder 850 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 850 outputs precoded data to the first frame forming unit 860 or the second frame forming unit 865.

In the case of the spatial diversity method, data of the same information is output to the first frame forming unit 860 and the second frame forming unit 865, respectively, and when encoded in the spatial multiplexing method, the first frame forming unit ( Different data is output to the 860 and the second frame forming unit 865.

12 is a diagram illustrating an example of a multiple input / output encoding scheme according to an embodiment of the present invention. The embodiment of FIG. 12 is STBC, which is one of multiple input / output encoding schemes, and may be used in the transmission apparatus of FIG. 8. The encoding scheme is one example, and the application of other multiple input / output encoding schemes is not excluded.

In the example of the STBC encoder, T denotes a symbol transmission period, s denotes an input symbol to be transmitted, and y denotes an output symbol. * Denotes a complex conjugate, and Tx # 1 and Tx # 2 denote transmission antennas 1 and 2, respectively.

According to the above example, at time t Tx # 1 transmits s ₀ , Tx # 2 transmits s ₁ , and at time t + T Tx # 1 transmits -s ₁ ^* and Tx # 2 transmits s ₀ ^* do. Each transmitting antenna transmits data of the same information of s ₀ and s ₁ within a transmission period. Accordingly, it can be seen that the encoding scheme is one of the space diversity scheme.

The first frame forming unit 860 and the second frame forming unit 865 form a frame into which a pilot signal is inserted so as to modulate the received signals in an orthogonal frequency division multiplex (OFDM) scheme.

The frame includes one pilot symbol period and M-1 data symbol periods. When the transmission system of FIG. 8 performs multiple input / output encoding using a plurality of antennas, a structure of a pilot symbol should be determined so that each transmission path can be distinguished from a receiving side.

13 (a) is a diagram showing the structure of a pilot symbol interval according to an embodiment of the present invention. The structure of the pilot symbol section of FIG. 13A may be used when multiple input / output encoding is performed to have two transmission paths as shown in FIG. 12.

In the case of FIG. 13A, pilot carrier information is interleaved and divided into even and odd pilots to distinguish two transmission paths. For example, frame data including even pilot carrier information in a pilot symbol period is transmitted through antenna 0, and frame data including odd pilot carrier information in a pilot symbol period is transmitted through antenna 1. do. Accordingly, the receiving side can distinguish each transmission path using the corresponding carrier index of the pilot symbol interval.

In the above embodiment, a channel corresponding to half of subcarriers may be estimated in one symbol. Therefore, high channel estimation performance can be obtained even for a transmission channel having a short coherence time.

FIG. 13B is a diagram illustrating another structure of a pilot symbol section according to an embodiment of the present invention. FIG. 13 (b) may also be used when multiple input / output encoding is performed to have two transmission paths as shown in FIG. 12.

13 (b) shows an embodiment of a Hadamard type pilot symbol interval. In the above embodiment, Hadamard transformation is performed in units of symbol intervals to distinguish two transmission paths. Accordingly, the even symbol interval includes the sum of two pilot carrier information for each transmission path, and the odd symbol interval includes the difference between two pilot carrier information.

For example, the even symbol interval includes a pilot value of a carrier (a) to be transmitted through antenna 0 and a pilot value of pilot carrier information (b) to be transmitted through antenna 1 (a + b). And a difference value ab of pilot carrier information a to be transmitted through the first antenna and pilot carrier information b to be transmitted through the first antenna. If the receiving side knows the sum / difference of the two pilot carrier information through the received pilot index, each transmission path can be distinguished.

In the above embodiment, since channels corresponding to all subcarriers can be estimated, delay spread of a channel that can be processed for each transmission path can be extended by a symbol length.

FIG. 13B is a diagram for easily distinguishing the two pilot carrier information and shows both the pilot carrier information in the frequency domain. In the case of an even symbol interval and an odd symbol interval diagram, impulses of two pilot carrier information are located at the same frequency point. In the case of the even-symbol interval diagram, the positions of the pilot carrier information to be transmitted through the antenna 0 and the pilot carrier information to be transmitted through the antenna 1 are shown to be different for ease of division, and the pilot carrier information is located at the same frequency point. Located.

13 (a) and 13 (b) are examples of two transmission paths, and when the transmission path is longer, pilot carrier information may be distinguished by the number of transmission paths, not odd or even. You can divide or perform Hadamard transformation on a symbol interval basis.

The first modulator 870 and the second modulator 875 load data output from the first frame former 860 and the second frame former 865 onto subcarriers of OFDM, respectively. Modulate for transmission.

The first transmitter 880 and the second transmitter 885 respectively convert a digital signal having a guard interval and a data interval output from the first modulator 870 and the second modulator 875 into an analog signal. Convert, and transmit the converted analog signal.

14 is a block diagram schematically illustrating an apparatus for receiving a signal according to an embodiment of the present invention. The embodiment of FIG. 14 may be included in a DVB receiver.

14 illustrates a receiver 1400, a synchronizer 1410, a demodulator 1420, a frame parsing unit 1430, a multiple input / output decoder 1440, and a first deinterleaver. 1450, a linear precoding decoder 1460, a symbol demapper 1470, a second D interleaver 1480, and a forward error correction decoder 1490. 14 illustrates a process of processing a signal in the signal receiving system, and the number of receiving paths is not determined.

The receiver 1400 down-converts the frequency band of the received RF signal and converts the frequency band into a digital signal. The synchronizer 1410 obtains and outputs a synchronization between a frequency domain and a time domain of the received signal output from the receiver 1400. The synchronization unit 1410 may use an offset result of the frequency domain of data output by the demodulator 1420 to acquire synchronization of the frequency domain signal.

The demodulator 1420 demodulates the received data output from the synchronizer 1410 and removes the guard interval. To this end, the demodulator 1420 converts the received data into the frequency domain, and decodes data values distributed in subcarriers into values assigned to each subcarrier.

The frame parser 1430 may output symbol data of a data symbol period excluding pilot symbols according to the frame structure of the signal demodulated by the demodulator 1420.

The multiple input / output decoder 1440 receives and decodes the data output from the frame parser 1430 and outputs one data string. The multiple input / output decoder 1440 outputs one data string by decoding according to a scheme corresponding to the scheme encoded by the multiple input / output encoder 150 of FIG.

The first deinterleaver 1450 performs de-interleaving on the data string output from the multiple input / output decoder 1440 to restore the data in the order before interleaving. The first deinterleaver 1450 is deinterleaved according to a method corresponding to the method interleaved by the second interleaver 140 of FIG. 1 to restore the order of data columns.

The linear precoding decoder 1460 restores data by performing an inverse process of distributing data in the signal transmission apparatus.

15 (a) is a block diagram schematically illustrating an example of a linear precoding decoder as an embodiment according to the present invention. The linear precoding decoder 1460 includes a serial / parallel converter 1462, a first decoder 1464, and a parallel / serial converter 1466.

The serial / parallel converter 1462 converts the input data into parallel data. The first decoding unit 1464 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 a vanderMonde matrix, a Hadamard matrix, a Golden code, or the like as shown in FIGS. 6 (a), 6 (b) and 6 (c), the first decoding unit 1464 ) Respectively restore the distributed data to the original data using the inverse matrix of the matrices.

The parallel / serial converter 1466 converts the parallel data received by the first decoder 1464 back into serial data and outputs the serial data.

15 (b) is a block diagram schematically illustrating another example of a linear precoding decoder according to an embodiment of the present invention. The linear precoding decoder 1460 includes a serial / parallel converter 1462, a second decoder 1463, and a parallel / serial converter 1465.

The serial / parallel converter 1462 converts the input data into parallel data, and the parallel / serial converter 1465 serializes the parallel data received by the second decoder 1463 again. Convert it to data and output it. The second decoding unit 1463 restores and outputs original data distributed in parallel data output from the serial / parallel conversion unit 1541 using Maximum Likelihood (ML) decoding.

The second decoder 1463 is an ML decoder considering a transmission scheme in a transmitter. The second decoding unit 1463 recovers the 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.

16 (a) to 16 (c) are diagrams illustrating an example of a 2x2 code matrix for recovering distributed symbols according to an embodiment of the present invention. The code matrix of FIGS. 16 (a) to 16 (c) is not the encoding matrix of FIGS. 6 (a) to 6 (c) but the 2 × 2 encoding matrix of FIGS. 9 (c) to 9 (e). Is the inverse matrix corresponding to. The matrix reconstructs and outputs data dispersed in two data input to the decoding unit of the linear precoding decoder 1460.

16 (a) is a diagram illustrating an example of a 2 × 2 code matrix according to an embodiment of the present invention. The matrix of FIG. 16A is a decoding matrix corresponding to the encoding matrix of FIG. 9C.

) 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.The matrix of FIG. 16 (a) 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.

16 (b) is a diagram illustrating another example of a 2 × 2 code matrix according to an embodiment of the present invention. The matrix of FIG. 16 (b) is a decoding matrix corresponding to the encoding matrix of FIG. 9 (d).

로 나누어 스케일링한다.The matrix of FIG. 16 (b) 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.

16 (c) illustrates another example of a 2 × 2 code matrix according to an embodiment of the present invention. The matrix of FIG. 16C is a decoding matrix corresponding to the encoding matrix of FIG. 9E. '*' In FIG. 16 (c) means 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.16 (c) 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.

The symbol demapper 1470 may restore the symbol data decoded by the linear precoding decoder 1460 into a bit string. The second deinterleaver 1480 performs de-interleaving on the data string output from the symbol demapper 1470 to restore the data in the order before interleaving. The second deinterleaver 1480 is deinterleaved according to a method corresponding to the method interleaved by the first interleaver 110 of FIG. 1 to restore the order of data columns.

The forward error correction decoding unit 1490 may forward error correct and decode the data whose order has been restored, detect an error occurring in the received data, and correct the error.

17 (a) is a block diagram schematically showing a forward error correction decoding unit according to an embodiment of the present invention. The forward error correction decoding unit of FIG. 17 (a) is a decoding unit corresponding to the turbo code of the serial concatenated type (SCCC) of FIG. The decoder includes a second MAP decoder 1702, a first operator 1704, a deinterleaver 1706, a first MAP decoder 1708, a second operator 1710, an interleaver 1712, and a determiner 1714. do.

A soft output iterative decoding method is used to decode the data encoded by the turbo code, and a MAP algorithm may be used as the decoding method using the method.

The first MAP decoder 1708 and the second MAP decoder 1702 of FIG. 17 (a) may receive reliability information on input symbols and reliability information on output symbols from the encoder, and estimate the outputs from the output. It is a soft-in soft-out (SISO) decoder that outputs respective reliability information.

The first MAP decoder 1708 and the second MAP decoder 1702 are decoders corresponding to the first convolutional encoder 102 and the second convolutional encoder 106 of Fig. 2 (a), respectively, and the encoding of Fig. 2 (a) is performed. The data is decoded and output in reverse.

The first MAP decoder 1708 receives the data output from the second deinterleaver 1480 and the data output from the interleaver 1712, and decodes the data according to the MAP algorithm. The first operation unit 1704 subtracts the data output from the interleaver 1712 from the data output from the first MAP decoder 1708 and outputs the data to the deinterleaver 1706.

The deinterleaver 1706 deinterleaves the input data, and outputs the mixed data to the first MAP decoder 1708 and the second calculator 1710. The second operator 1710 subtracts the data output from the deinterleaver 1706 from the data output from the first MAP decoder 1708 and inputs the feedback to the interleaver 1712 to feed back the data.

 The first MAP decoder 1708 decodes the input data according to the MAP algorithm and outputs the decoded data to the decision unit 1714. The decision unit 1714 is a symbol input to the decision unit 1714 for the final reliability value. Lower the determined value for and print it.

17 (b) is a block diagram schematically showing another forward error correction decoding unit as an embodiment according to the present invention. The forward error correction decoding unit of FIG. 17 (b) is a decoding unit corresponding to the turbo code of the parallel chain type (PCCC) of FIG. 2 (b). The decoder includes a serial / parallel converter 1701, a fourth MAP decoder 1703, a third operator 1705, a deinterleaver 1707, a third MAP decoder 1709, a fourth operator 1711, and an interleaver 1713. And a decision unit 1715.

The difference between the decoder of FIG. 17B and the decoder of FIG. 17A is that the third MAP decoder 1709 receives the data output from the second deinterleaver 1480 and performs decoding. This is to calculate reliability values transmitted in parallel due to the characteristics of a parallel chain type (PCCC) scheme.

 The serial / parallel converter 1701 selects data output from the second deinterleaver 1480 in the inverse of the method selected by the parallel / serial converter 107 of FIG. 1703 and the third MAP decoder 1709.

18 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.

18 illustrates a first receiver 1800, a second receiver 1805, a first synchronizer 1810, a second synchronizer 1815, a first demodulator 1820, and a second demodulator 1825. ), A first frame parser 1830, a second frame parser 1835, a multiple input / output decoder 1840, a third deinterleaver 1850, a linear precoding decoder 1860, a symbol demapper 1870, A fourth deinterleaver 1880 and a forward error correction decoder 1890 are included.

The first receiver 1800 and the second receiver 1805 each receive an RF signal, downconvert the frequency band, and convert the converted frequency into a digital signal. The first synchronizer 1810 and the second synchronizer 1815 acquire and output synchronization of a frequency domain and a time domain of the received signal output from the first receiver 1800 and the second receiver 1805, respectively. The first synchronization unit 1810 and the second synchronization unit 1815 are offsets of the frequency domain of data output from the first demodulator 1820 and the second demodulator 1825, respectively, in order to obtain synchronization of the frequency domain signals. (offset) results are available.

The first demodulator 1820 demodulates the received data output from the first synchronizer 1810. To this end, the first demodulator 1820 converts the received data into the frequency domain, and decodes the data value distributed in the subcarriers into a value allocated to each subcarrier. The second demodulator 1825 demodulates the received data output from the second synchronizer 1815.

The first frame parser 1830 and the second frame parser 1835 distinguish pilot paths according to frame structures of signals demodulated by the first demodulator 1820 and the second demodulator 1825, respectively. The symbol data of the data symbol section excluding the symbol may be output.

The multiple input / output decoder 1840 receives and decodes the data output from the first frame parser 1830 and the second frame parser 1835, respectively, and outputs one data string.

19 is a diagram illustrating an example of a multiple input / output decoding scheme according to an embodiment of the present invention. 19 is a diagram illustrating an example of a corresponding decoding at a receiving side when the transmitting side transmits data by multiple input / output encoding using the STBC method, and the transmitting side uses two transmitting antennas. This is an example and the application of other multiple input / output methods is not excluded.

R (k), h (k), s (k), and n (k) in the above equations represent symbols received at the receiver, channel response, symbol values transmitted at the transmitter, and channel noise, respectively. Subscripts s, i, 0, and 1 denote an sth transmission symbol, an ith reception antenna, a 0th transmission antenna, and a 1st transmission antenna, respectively. '*' Represents a complex conjugate. For example, h _{s , 1, i} (k) indicates a response of the channel experienced by the transmitted symbol when the s-th transmitted symbol is received by the i-th reception antenna. r _{s + 1, i} (k) represents the s + 1 th received symbol received at the i th receive antenna.

According to the equation of FIG. 19, r _{s , i} (k) _, which is the s-th reception symbol received at the i-th reception antenna, is the s-th symbol value transmitted through the channel from the 0th transmission antenna to the i-th reception antenna, and 1st In the transmitting antenna, the i-th receiving antenna is the sum of the s-th symbol value transmitted through the channel and the sum of the channel noise of each channel (n _s (k)).

In addition, r _{s + 1, i} (k), which is the s + 1 th received symbol received at the i th receive antenna, is the s + 1 th symbol value transmitted through the channel from the 0 th transmit antenna to the i th receive antenna, and the first transmit It is the sum of the s + 1th symbol value transmitted through the channel and the sum of the channel noise of each channel (n _s (k)).

20 is a diagram illustrating a specific example of FIG. 19 as an embodiment according to the present invention. 20 is an example of decoding when a transmitter transmits data through multiple input / output encoding using the STBC method, and the transmitter transmits the data using two transmission antennas and receives the signal through one antenna at the receiver. to be. That is, this is a case of receiving data transmitted by using one receiving antenna.

When two transmitting antennas are used at the transmitting side and one antenna is used at the receiving side, there may be two transmission channels.

H ₀ and s ₀ in the above equations represent the transmission channel response from the transmitting antenna 0 to the receiving antenna and the symbols transmitted from the transmitting antenna 0, respectively, and h ₁ and s ₁ are received from the transmitting antenna 1 respectively. The transmission channel response to the antenna and the symbol transmitted by the first antenna at the transmitting side are shown. '*' Represents a complex conjugate, and s ₀ 'and s ₁ ' in the following formulas represent a restored symbol.

And r ₀ and r ₁ represent symbols received at the receiving antenna at t time and symbols received at the receiving antenna at t + T time after the transmission period T, respectively, and n ₀ and n ₁ are the respective reception times. Denotes the sum of channel noise of each transmission path.

As shown in Equation 20 of FIG. 20, the signal received by the receiving antenna may be expressed as a value obtained by adding a value that the signal transmitted by each transmitting antenna has experienced each transmission channel. The recovered symbol is calculated using the received value and each channel response value.

Hereinafter, the signal processing from the multiple input / output decoder 1840 to the forward error correction decoding unit 1890 is the same as described with reference to FIG. 14.

21 is a block diagram schematically showing another example of a signal transmission apparatus according to an embodiment of the present invention. 22 is a block diagram schematically showing another example of a signal receiving apparatus according to an embodiment of the present invention.

21 and 22 are examples applied to a system of a single input single output (SISO) method rather than a multiple input / output method.

The signal transmission apparatus of FIG. 21 includes a forward error correction unit 2100, a first interleaver 2110, a symbol mapper 2120, a linear precoding unit 2130, a second interleaver 2140, and frame formation. A frame builder 2150, a modulator 2160, and a transmitter 2170 are included.

The signal receiver of FIG. 22 includes a receiver 2200, a synchronizer 2210, a demodulator 2220, a frame parsing unit 2230, a first deinterleaver 2240, and a linear precoding decoder 2250. ), A symbol demapper 2260, a second deinterleaver 2270, and a forward error correction decoder 2280.

The signal transmission device and the signal receiving device go through the processing as described with reference to FIGS. 1 and 14, respectively. However, in the transceivers of FIGS. 21 and 22, since a single input single output method is applied instead of a multiple input / output method, a multiple input / output encoding process and a multiple input / output decoding process are not used.

That is, symbol data that has undergone linear precoding and interleaving to be robust to the frequency selective fading of the channel is input to the frame forming unit 2150, and the frame forming unit 2150 is shown in FIG. 7 based on the input symbol data. The frame data of the structure is formed and output. In the case of the single input single output method, it is not necessary to distinguish transmission paths according to multiple inputs and outputs as shown in FIGS. 13 (a) and 13 (b).

In the case of the signal receiving apparatus, a symbol process parsed by the frame parser 2230 is output to the first deinterleaver 2240 to perform a reverse process of processing to make the transmitting apparatus robust to frequency selective fading of a channel. Do it.

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

Forward error correction encoding is performed so that the receiving side can detect and correct a transmission error with respect to the input data (S2300). A turbo code may be used for the forward error correction encoding.

Interleaving is performed on the encoded data so as to be robust to burst errors in the transmission channel, and the interleaved data is mapped into symbols according to a corresponding transmission / reception system in operation S2302. QAM, QPSK, etc. may be used for the symbol mapping.

In order to make the symbol data robust to frequency selective fading of a channel, precoding is performed such that the mapped symbol data is distributed to a plurality of output symbols in a frequency domain (S2304). The symbol data are interleaved (S2306) and output.

Thus, reducing the likelihood that all information is lost to fading when undergoing a frequency selective fading channel, ensures that the distributed symbol data does not experience the same frequency selective fading. The interleaving may use a convolution interleaver, a block interleaver, etc., which may be selected according to an implementation example.

The interleaved symbol data is multi-input / output encoded to be transmitted through a plurality of antennas (S2308). 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 S2310, the encoded data is converted into a transmission frame, modulated, and transmitted according to the number of the multi-input / output transmission paths. The transmission frame may include a pilot carrier symbol interval and a data symbol interval, and the pilot carrier symbol interval may have a structure capable of distinguishing a transmission path.

However, when applied to a signal transmission / reception system of a single input single output method instead of a multiple input / output method, the multiple input / output encoding step of step S2308 is not performed, and a division of a transmission path is not necessary.

24 is a flowchart illustrating a signal receiving method according to an embodiment of the present invention.

The signal receiving apparatus receives and synchronizes a signal transmitted from the transmitting apparatus, distinguishes a transmission path, and demodulates the data into a data frame (S2400).

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 (S2402).

In order to recover the symbol data processed to be robust to the frequency selective fading of the channel, deinterleaving inverse to the interleaved method in the signal transmission apparatus (S2404), and precoding the data sequence whose order is restored to the deinterleaving. Inversely, decoding is performed to restore original symbol data dispersed in a plurality of symbol data in a frequency domain (S2406).

De-mapping the recovered symbol data to restore the corresponding bit data, and deinterleaving the bit data to restore the original bit data (S2408).

Then, forward error correction decoding is performed on the data whose order is restored to detect a transmission error and correct the error (S2410). Decoding of the turbo code may be used for the forward error correction decoding.

However, when applied to a signal transmission / reception system of a single input single output method instead of a multiple input / output method, the multiple input / output decoding step of step S2402 is not performed, and a division of a transmission path is not necessary.

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 such as broadcasting or communication.

The present invention is not limited to the above-described embodiments, and can be modified by those skilled in the art as can be seen from the appended claims, and such variations 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, it is easy to switch to the proposed signal transmission / reception system using an existing signal transmission / reception network network, and it is possible to reduce costs.

In addition, the data rate can be improved based on the SNR gain, and channel estimation can be performed for a transmission channel having a long delay spread, thereby increasing the signal transmission distance. Therefore, there is an effect that can increase the signal transmission and reception performance of the overall transmission and reception system.

Claims (13)

A turbo code encoder for error correction encoding and outputting the input data; An interleaver for interleaving the error correction encoded data; And And a symbol mapper for mapping the interleaved data into symbol data according to a corresponding transmission scheme. The method of claim 1, And a fading coding unit for distributing the symbol data in a frequency domain and interleaving and outputting the distributed data. In the signal transmission apparatus, A frame forming unit for forming frame data including a pilot symbol section including pilot carrier information and a data symbol section including input symbol data information; A modulator for modulating the frame data according to an orthogonal frequency multiplexing scheme; And And a transmitter for converting the modulated data into an analog signal and transmitting the analog signal. A turbo code encoder for encoding input data to detect and correct errors in the data; An interleaver for interleaving the encoded data; A symbol mapper which maps the interleaved data into symbol data according to a corresponding transmission scheme; A fading coding unit for distributing the symbol data in a frequency domain and interleaving and outputting the distributed data; A multiple input / output encoder for encoding the faded coded output data to be transmitted in multiplexes; A frame forming unit for forming frame data including a pilot symbol period and a data symbol period; And And a modulator for modulating and transmitting the frame data according to an orthogonal frequency multiplexing scheme. A turbo code encoder for encoding input data to detect and correct errors in the data; An interleaver for interleaving the error correction encoded data; A symbol mapper which maps the interleaved data into symbol data according to a corresponding transmission scheme; A fading coding unit for distributing the symbol data in a frequency domain and interleaving the distributed data to output the interleaved data; A frame forming unit for forming frame data including a pilot symbol period and a data symbol period; And And a modulator for modulating and transmitting the frame data according to an orthogonal frequency multiplexing scheme. A turbo code encoding step of encoding the input data to detect and correct errors in the data; Interleaving the encoded data; Mapping the interleaved data to symbol data according to a corresponding transmission scheme; A fading coding step of distributing the symbol data in a frequency domain and interleaving and outputting the distributed data; Multiple input / output encoding so that the faded-coded output data can be transmitted in multiplexes; Forming frame data including a pilot symbol period and a data symbol period; And And modulating and transmitting the frame data according to an orthogonal frequency multiplexing scheme. A turbo code encoding step of encoding the input data to detect and correct errors in the data; Interleaving the encoded data; Mapping the interleaved data to symbol data according to a corresponding transmission scheme; A fading coding step of distributing the symbol data in a frequency domain and interleaving and outputting the distributed data; Forming frame data including a pilot symbol period and a data symbol period; And And modulating and transmitting the frame data according to an orthogonal frequency multiplexing scheme. A symbol demapper which demaps input symbol data and outputs bit data corresponding to the symbol; A deinterleaver for deinterleaving the demapped bit data to restore order; And And a turbo code decoder for error correction decoding the deinterleaved data. The method of claim 8, And a fading decoding unit for de-interleaving the input symbol data, restoring data distributed in a frequency domain, and outputting the recovered symbol data to a symbol demapper. A demodulator for demodulating the received signal according to an orthogonal frequency multiplexing scheme; A frame parsing unit for parsing the demodulated frame data and restoring symbol data of a corresponding transmission path; A multiple input / output decoder configured to multiple input / output decode the symbol data to output one symbol data string; A fading decoding unit for de-interleaving the output symbol data sequence and restoring and outputting data distributed in a frequency domain; A symbol demapper outputting bit data corresponding to the symbol by demapping the restored and outputted symbol data; A deinterleaver for deinterleaving the demapped bit data to restore order; And And a turbo code decoder to decode the deinterleaved data to detect and correct errors. A demodulator for demodulating the received signal according to an orthogonal frequency multiplexing scheme; A frame parsing unit for parsing the demodulated frame data and restoring the transmitted symbol data; A fading decoding unit for de-interleaving the output symbol data and restoring and outputting data distributed in a frequency domain; A symbol demapper outputting bit data corresponding to the symbol by demapping the restored and outputted symbol data; A deinterleaver for deinterleaving the demapped bit data to restore order; And And a turbo code decoder to decode the deinterleaved data to detect and correct errors. Demodulating the received signal according to an orthogonal frequency multiplexing scheme; Parsing the demodulated frame data to restore symbol data of a corresponding transmission path; A multiple input / output decoding step of decoding the symbol data and outputting one symbol data string; A fading decoding step of de-interleaving the output symbol data sequence and restoring and outputting data distributed in a frequency domain; Demapping the fading decoded symbol data to output bit data corresponding to the symbol; Deinterleaving the demapped bit data to restore order; And And turbo code decoding to decode the deinterleaved data to detect and correct errors. Demodulating the received signal according to an orthogonal frequency multiplexing scheme; Parsing the demodulated frame data to recover the transmitted symbol data; A fading decoding step of de-interleaving the output symbol data and restoring and outputting data distributed in a frequency domain; Demapping the restored and outputted symbol data and outputting bit data corresponding to the symbol; Deinterleaving the demapped bit data to restore order; And And turbo code decoding to decode the deinterleaved data to detect and correct errors.

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