WO2008130144A1

WO2008130144A1 - Method for signal transmitting and apparatus for the same, method for signal receiving and apparatus for the same

Info

Publication number: WO2008130144A1
Application number: PCT/KR2008/002188
Authority: WO
Inventors: Woo Suk Ko; Sang Chul Moon
Original assignee: Lg Electronics Inc.
Priority date: 2007-04-19
Filing date: 2008-04-18
Publication date: 2008-10-30
Also published as: KR20080094190A

Abstract

A signal transmission/reception method and a signal transmission/reception apparatus are disclosed. The signal transmission method includes dispersing symbol data mapped based on a given transmission scheme in a frequency domain, interleaving the dispersed data, and MIMO-encoding the interleaved data such that the interleaved data can be transmitted on multiple paths. Therefore, input data can be dispersed in the frequency domain, so that it can be robust to frequency- selective fading resulting from a delay time of each transmission channel. Also, it is possible to improve signal reception performance of a signl reception apparatus.

Description

METHOD FOR SIGNAL TRANSMITTING AND APPARATUS FOR THE SAME, METHOD FOR SIGNAL RECEIVING AND

APPARATUS FOR THE SAME

Technical Field

[1] The present invention relates to a signal transmission/reception method and a signal transmission/reception apparatus, and more particularly, to a signal transmission/ reception method and a signal transmission/reception apparatus which are robust to time- selective fading. Background Art

[2] With the advance of technologies, the size of data desired by the user is on an increasing trend; however, there is a certain limitation in extending transmission resources for transmission of the data to the user side. For this reason, various technologies have been developed to increase data transmission efficiency using limited transmission resources.

[3] Among these technologies, a Multi Input Multi Output (MIMO) scheme has been proposed as a digital data transmission scheme to increase data transmission efficiency using a plurality of transmission/reception antennas.

[4] A transmission/reception system using a single carrier (SC) is efficient in terms of transmission power owing to a lower Peak-to- Average Power Ratio (PAPR) in a time domain compared with a transmission/reception system using multiple carriers, such as Orthogonal Frequency Division Multiplexing (OFDM).

[5] However, a transmission channel undergoing a Doppler effect is subject to time- selective fading, and very severe size distortion in a time domain depending on the moving speed of a receiver. As a result, there is a problem that a Signal-to-Noise Ratio (SNR) differs in different time domains and a reception rate is reduced in a time domain where the SNR is very low.

[6] In the case of using the MIMO scheme, a plurality of antennas can be used to obtain an array gain so as to improve an average SNR. Also, a diversity gain can be obtained when fading of a transmission channel from each transmission antenna to each reception antenna is independent.

[7] However, the MIMO scheme is problematic in that, in terms of only one specific transmission channel, this channel cannot help being subject to time-selective fading as ever.

Disclosure of Invention Technical Problem

[8] An object of the present invention devised to solve the problem lies on a signal transmission/reception method and a signal transmission/reception apparatus which are robust to time-selective fading. Technical Solution

[9] The object of the present invention can be achieved by providing a signal transmission apparatus comprising a symbol mapper, a precoder, an interleaver, and a modulator. The symbol mapper maps input data to symbol data based on a given transmission scheme. The precoder precodes the mapped symbol data to disperse the mapped symbol data into two or more symbol data in a time domain. The interleaver interleaves symbol data of an output data stream from the precoder according to a predetermined rule. The modulator modulates the interleaved data such that the interleaved data can be transmitted on a single carrier.

[10] The precoder may comprise a serial/parallel converter for converting input serial data into parallel data, an encoder for multiplying the parallel data by a predetermined encoding matrix to disperse the parallel data, and a parallel/serial converter for converting the dispersed parallel data into serial data.

[11] The signal transmission apparatus may further comprise a Multi Input Multi Output

(MIMO) encoder for MIMO-encoding the interleaved data such that the interleaved data can be transmitted through a plurality of antennas.

[12] In another aspect of the present invention, provided herein is a signal transmission method comprising precoding symbol data mapped based on a given transmission scheme to disperse the mapped symbol data into two or more symbol data in a time domain, interleaving symbol data of a precoded data stream according to a predetermined rule, and modulating the interleaved data such that the interleaved data can be transmitted on a single carrier.

[13] The signal transmission method may further comprise MIMO-encoding the interleaved data such that the interleaved data can be transmitted through a plurality of antennas.

[14] In another aspect of the present invention, provided herein is a signal reception apparatus comprising a deinterleaver, a precoding decoder, and a symbol demapper.

[15] The deinterleaver deinterleaves one symbol data stream demodulated after being received on a single carrier, to restore an order of symbol data of the symbol data stream to an original one. The precoding decoder restores symbol data dispersed in a time domain from the order-restored symbol data. The symbol demapper demaps the restored symbol data to output bit data of a corresponding symbol.

[16] The signal reception apparatus may further comprise a MIMO decoder for MIMO- decoding data demodulated after being received through a plurality of antennas, to output the one symbol data stream.

[17] In a further aspect of the present invention, provided herein is a signal reception method comprising deinterleaving one symbol data stream demodulated after being received on a single carrier, to restore an order of symbol data of the symbol data stream to an original one, restoring symbol data dispersed in a time domain from the order-restored symbol data, and demapping the restored symbol data to output bit data of a corresponding symbol.

[18] The signal reception method may further comprise MIMO-decoding data demodulated after being received through a plurality of antennas, to output the one symbol data stream.

Advantageous Effects

[19] According to a signal transmission/reception method and a signal transmission/ reception apparatus of the present invention, input data can be dispersed and transmitted in a time domain, so that it can be robust to time-selective fading of each transmission channel. Also, it is possible to improve signal reception performance of a receiver. Brief Description of the Drawings

[20] The accompanying drawings, which are included to provide a further understanding of the invention, illustrate embodiments of the invention and together with the description serve to explain the principle of the invention.

[21] In the drawings:

[22] FIG. 1 is a schematic block diagram of a signal transmission apparatus according to one embodiment of the present invention.

[23] FIG. 2 is a schematic block diagram of a linear precoder according to one embodiment of the present invention.

[24] FIG. 3 is a view showing a code matrix for dispersion of input data according to one embodiment of the present invention.

[25] FIG. 4 is a view showing another code matrix for dispersion of input data according to one embodiment of the present invention.

[26] FIG. 5 is a schematic block diagram of a signal transmission apparatus having a plurality of transmission paths according to one embodiment of the present invention.

[27] FIGs. 6 to 10 are views showing examples of a 2x2 code matrix for dispersion of input symbols according to one embodiment of the present invention.

[28] FIG. 11 is a schematic block diagram of a signal reception apparatus according to one embodiment of the present invention.

[29] FIG. 12 is a block diagram schematically showing an example of a linear precoding decoder according to one embodiment of the present invention.

[30] FIG. 13 is a block diagram schematically showing another example of the linear precoding decoder according to one embodiment of the present invention.

[31] FIG. 14 is a schematic block diagram of a signal reception apparatus having a plurality of reception paths according to one embodiment of the present invention.

[32] FIGs. 15 to 19 are views showing examples of a 2x2 code matrix for restoration of dispersed symbols according to one embodiment of the present invention.

[33] FIG. 20 is a schematic block diagram of another example of the signal transmission apparatus according to one embodiment of the present invention.

[34] FIG. 21 is a schematic block diagram of another example of the signal reception apparatus according to one embodiment of the present invention.

[35] FIG. 22 is a flowchart illustrating a signal transmission/reception method according to one embodiment of the present invention. Best Mode for Carrying Out the Invention

[36] Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the invention rather unclear.

[37] Besides, although terms used in the present invention are possibly selected from the currently well-known ones, some terms are arbitrarily chosen by the inventor in some cases so that their meanings are explained in detail in the following description. Hence, the present invention should be understood with the intended meanings of the corresponding terms chosen by the inventor instead of the simple names or meanings of the terms themselves.

[38] FIG. 1 is a schematic block diagram of a signal transmission apparatus according to one embodiment of the present invention. In this embodiment, the signal transmission apparatus employs a Multi Input Multi Output (MIMO) scheme for multiple input/ output.

[39] The signal transmission apparatus of FIG. 1 transmits a signal using a single carrier

(SC). In the case where the signal transmission apparatus transmits video data of a broadcast signal, it may be a broadcast signal transmission system. The embodiment of the signal transmission apparatus according to the present invention will hereinafter be described with reference to FIG. 1.

[40] The embodiment of FIG. 1 comprises an outer coder 100, outer interleaver 110, inner coder 120, inner interleaver 130, symbol mapper 140, linear precoder 150, in- terleaver 160, MIMO encoder 170, frame builder 180, SC modulator 190, and transmitting unit 195. The embodiment of FIG. 1 will be described centering around a signal processing process of the signal transmission apparatus under the condition that the number of transmission paths is not fixed.

[41] The outer coder 100 and the outer interleaver 110 code and interleave multiplexed data, respectively, to improve transmission performance of an input signal. For example, a Reed-Solomon coding scheme may be used for the outer coding and a convolution interleaving scheme may be used for the interleaving.

[42] The inner coder 120 and the inner interleaver 130 again code and interleave a signal to be transmitted, respectively, to cope with occurrence of an error in the signal to be transmitted. The types of the respective coders and interleavers may be different depending on coding and interleaving schemes used in the signal transmission apparatus.

[43] The symbol mapper 140 maps the signal to be transmitted to symbol data based on a mapping scheme such as 16QAM, 64QAM or QPSK in consideration of a transmission mode, transmission scheme, etc., and outputs the mapped symbol data to the linear precoder 150.

[44] The linear precoder 150 disperses symbol data inputted thereto into a plurality of output symbol data in a time domain to reduce the probability for all information to be lost due to fading when a time- selective fading channel is experienced.

[45] FIG. 2 is a schematic block diagram of the linear precoder according to one embodiment of the present invention. The precoder 150 includes a serial/parallel converter 152, encoder 154, and parallel/serial converter 156.

[46] The serial/parallel converter 152 converts input data into parallel data and outputs the converted parallel data to the encoder 154. The encoder 154 disperses the parallel data inputted thereto into a plurality of data in a time domain through encoding matrixing.

[47] FIG. 3 is a view showing a code matrix for dispersion of input data according to one embodiment of the present invention. FIG. 3 shows an example of an encoding matrix for dispersing the input data into a plurality of output data, which is called a vanderMonde matrix. In this example, the input data can be arranged in parallel by a length corresponding to the number L of output data.

[48] θ of the matrix can be expressed by the following equation 1, and may be defined in a different way. The vanderMonde matrix can adjust the matrix components thereof using the equation 1. [49] The matrix reflects each input data in output data by rotating it by a corresponding phase of the equation 1. Thus, input values can be dispersed into at least two output values according to characteristics of the matrix.

[50] [Equation 1]

[51]

[52] In the above equation 1, L represents the number of output data. Assuming that a group of data inputted to the encoder 154 in FIG. 2 is x and a group of data encoded and outputted by the encoder 154 through the matrix is y, y can be expressed by the following equation 2.

[53] [Equation 2]

[54]

y = ® x

[55] FIG. 4 is a view showing another code matrix for dispersion of input data according to one embodiment of the present invention. FIG. 4 shows an example of an encoding matrix for dispersing the input data into a plurality of output data, which is called a Hadamard matrix. The matrix of FIG. 4 has a general form extended to a size of L = 2 , where 'L' represents the number of output symbols into which each input symbol is to be dispersed.

[56] The output symbols of this matrix can be obtained from additions and subtractions of L input symbols. In other words, each input symbol can be dispersed into L output symbols.

[57] Similarly, in the case of the matrix of FIG. 4, assuming that a group of data inputted to the encoder 154 in FIG. 2 is x and a group of data encoded and outputted by the encoder 154 through the matrix is y, y is a product of the matrix and x.

[58] The parallel/serial converter 156 again converts the data received from the encoder

154 into serial data and outputs the converted serial data to the interleaver 160.

[59] The interleaver 160 again interleaves the symbol data outputted from the linear precoder 150 and outputs the interleaved data to the MIMO encoder 170. That is, the interleaver 160 performs interleaving such that the symbol data dispersed into the data outputted from the linear precoder 150 cannot be subject to the same time- selective fading. A convolution interleaver, block interleaver or the like may be used as the interleaver 160.

[60] The linear precoder 150 and the interleaver 160 are parts to process data to be transmitted such that the data can be robust to time-selective fading of a channel. The MIMO encoder 170 performs MIMO encoding with respect to the data interleaved by the interleaver 160 such that the interleaved data can be transmitted on a plurality of transmission antennas, and outputs the resulting data to the frame builder 180.

[61] The MIMO encoding may be broadly classified into a spatial multiplexing scheme and a spatial diversity scheme. The spatial multiplexing scheme is a scheme where a transmitter and a receiver transmit different data simultaneously using multiple antennas, thereby enabling data to be transmitted at a higher speed with no further increase in system bandwidth. The spatial diversity scheme is a scheme where data of the same information is transmitted through multiple transmission antennas to obtain transmission diversity.

[62] Here, a space-time block code (STBC), a space-frequency block code (SFBC), a space-time trellis code (STTC), etc can be used for the MIMO encoder 170 of the spatial diversity scheme. A scheme for simply dividing and transmitting a data stream by the number of transmission antennas, a full-diversity full-rate (FDFR) code, a linear dispersion code (LDC), a Vertical-Bell Lab. layered space-time (V-BLAST), a diagonal-BLAST (D-BLAST), etc. can be used for the MIMO encoder 170 of the spatial multiplex scheme.

[63] The frame builder 180 builds a transmission frame by inserting a synchronous signal, a pilot signal, etc. in the precoded and MIMO-encoded symbol data such that the symbol data can be modulated based on a given single carrier (SC) transmission scheme, and outputs the built transmission frame to the SC modulator 190. For example, in the case where the given SC transmission scheme is a Vestigial Side Bands (VSB) scheme, the transmission frame includes a segment synchronous signal and a field synchronous signal.

[64] The SC modulator 190 modulates the frame outputted from the frame builder 180 such that the data of the frame can be transmitted on a given single carrier, and outputs the modulated frame to the transmitting unit 195. The transmitting unit 195 converts a digital modulated signal outputted from the SC modulator 190 into an analog signal and transmits the analog signal.

[65] FIG. 5 is a schematic block diagram of a signal transmission apparatus having a plurality of transmission paths according to one embodiment of the present invention. For the convenience of description, the case where the number of transmission paths is two will hereinafter be taken as an example.

[66] The embodiment of FIG. 5 comprises an outer coder 400, outer interleaver 410, inner coding & interleaving unit 420, symbol mapper 430, linear precoder 440, interleaver 450, MIMO encoder 460, first frame builder 470, second frame builder 475, first modulator 480, second modulator 485, first transmitting unit 490, and second transmitting unit 495.

[67] A signal processing process from the outer coder 400 to the MIMO encoder 460 is the same as that described in FIG. 1.

[68] That is, the outer coder 400 and the outer interleaver 410 code and interleave code and interleave input data, respectively. For example, in a Vestigial Side Bands (VSB) system, a Reed-Solomon coding scheme may be used for the outer coding and a convolution interleaving scheme may be used for the interleaving.

[69] The inner coder and the inner interleaver again code and interleave a signal to be transmitted, respectively, to cope with occurrence of an error in the signal to be transmitted.

[70] For example, in the VSB system, the inner interleaver is combined with the inner coder in the form of virtual interleaving to constitute a trellis coder. As a result, in the case where the inner coding and the inner interleaving are together performed in the trellis coder as in the VSB system, which is an example of the single carrier transmission system, the inner coder and the inner interleaver can be depicted as the inner coding & interleaving unit 420, which is one block, as shown in FIG. 5.

[71] However, in a different single carrier transmission system in which the inner coding and the inner interleaving are performed separately, the inner coder and the inner interleaver can be depicted as separate blocks as shown in FIG. 1. That is, this configuration may be different according to different application examples of the transmission/reception system.

[72] The symbol mapper 430 maps a signal to be transmitted to symbol data based on a mapping scheme in consideration of a transmission mode, transmission scheme, etc, and outputs the mapped symbol data to the linear precoder 440. For example, in an 8VSB system, the symbol mapper 430 maps 3-bit data outputted from the inner coding & interleaving unit 420 to one of eight VSB symbol data and outputs the mapped symbol data. That is, the symbol mapper 430 acts to vary the power level of a signal to be transmitted to a desired value before the signal is transmitted. In the 8VSB system, the output level of the symbol mapper 430 is one of symbol values (amplitude levels) of eight steps, namely, -168, -120, -72, -24, 24, 72, 120 and 168.

[73] The linear precoder 440 disperses symbol data inputted thereto into a plurality of output symbol data in a time domain to reduce the probability for all information to be lost due to fading when a time- selective fading channel is experienced. The linear precoder 440 includes a serial/parallel converter, encoder, and parallel/serial converter.

[74] FIGs. 6 to 10 are views showing examples of a 2x2 code matrix for dispersion of input symbols according to one embodiment of the present invention. The code matrices of FIGs. 6 to 10 are applicable to the signal transmission apparatus as shown in FIG. 5, and disperse two data inputted to the encoder in the linear precoder 440 into two output data.

[75] The matrix of FIG. 6 is an example of the vanderMonde matrix described in FIG. 3.

[76] The matrix of FIG. 6 adds a first one of the two input data and a second one of the two input data rotated 45 degrees (

4

) in phase to provide first output data, and adds the first input data and the second input data rotated 225 degrees (

S n

) in phase to provide second output data. Then, the matrix of FIG. 6 scales each output data by dividing it by

[77] The matrix of FIG. 7 is an example of the Hadamard matrix described in FIG. 4.

[78] The matrix of FIG. 7 adds a first one of the two input data and a second one of the two input data to provide first output data, and subtracts the second input data from the first input data to provide second output data. Then, the matrix of FIG. 7 scales each output data by dividing it by

[79] FIG. 8 shows another example of the input symbol dispersion code matrix applicable to FIG. 5 according to one embodiment of the present invention. The matrix of FIG. 8 is an example of another code matrix different from the matrices described in FIGs. 3 and 4.

[80] The matrix of FIG. 8 adds a first one of the two input data rotated 45 degrees ( n

4 ) in phase and a second one of the two input data rotated -45 degrees ( π

^~ T

) in phase to provide first output data, and subtracts the second input data rotated -45 degrees in phase from the first input data rotated 45 degrees in phase to provide second output data. Then, the matrix of FIG. 8 scales each output data by dividing it by

V2 [81] FIG. 9 shows another example of the input symbol dispersion code matrix applicable to FIG. 5 according to one embodiment of the present invention. The matrix of FIG. 9 is an example of another code matrix different from the matrices described in FIGs. 3 and 4.

[82] The matrix of FIG. 9 adds a first one of the two input data multiplied by 0.5 to a second one of the two input data to provide first output data, and subtracts the second input data multiplied by 0.5 from the first input data to provide second output data. Then, the matrix of FIG. 9 scales each output data by dividing it by

1.25

[83] FIG. 10 shows another example of the input symbol dispersion code matrix applicable to FIG. 5 according to one embodiment of the present invention. The matrix of FIG. 10 is an example of another code matrix different from the matrices described in FIGs. 3 and 4. In FIG. 10, '*' means a complex conjugate of input data.

[84] The matrix of FIG. 10 adds a first one of the two input data rotated 90 degrees ( π

) in phase and a second one of the two input data to provide first output data, and adds a complex conjugate of the first input data and a complex conjugate of the second input data rotated -90 degrees ( n

^" T

) in phase to provide second output data. Then, the matrix of FIG. 10 scales each output data by dividing it by

[85] The interleaver 450 again interleaves the symbol data outputted from the linear precoder 440 and outputs the interleaved data to the MIMO encoder 460. A convolution interleaver, block interleaver or the like may be used as the interleaver 450.

[86] The convolution interleaver interleaves symbol data sequentially inputted thereto to rearrange the order of the inputted symbol data. The block interleaver receives symbol data on a block basis and interleaves the received symbol data to rearrange the order of the received symbol data. The depths of these interleavers and the block size of the block interleaver may be different according to different embodiments.

[87] The interleaver 450 acts to interleave the data outputted from the linear precoder

440 such that the symbol data dispersed into the data outputted from the linear precoder 150 cannot be subject to the same time-selective fading. The type of the interleaver 450 may be different according to different embodiments of a transmission/ reception system.

[88] The MIMO encoder 460 encodes the data interleaved by the interleaver 450 such that the interleaved data can be transmitted on a plurality of transmission antennas. A spatial multiplexing scheme or spatial diversity scheme may be used for the MIMO encoding. That is, the interleaved data is outputted to the MIMO encoder 460, which then encodes and outputs symbol data inputted thereto such that the symbol data can be transmitted on a plurality of transmission antennas. For example, in the case where the number of transmission paths is two, the MIMO encoder 460 outputs the encoded data to the first frame builder 470 and second frame builder 475.

[89] In the case where the MIMO encoding scheme is a spatial diversity scheme, data of the same information is outputted to the first frame builder 470 and second frame builder 475. In the case where the MIMO encoding scheme is a spatial multiplexing scheme, different data are outputted to the first frame builder 470 and second frame builder 475, respectively.

[90] The first frame builder 470 builds a transmission frame by inserting a synchronous signal, a pilot signal, etc. in the precoded and MIMO-encoded signal, and outputs the built transmission frame to the first modulator 480. Similarly, the second frame builder 475 builds a transmission frame by inserting a synchronous signal, a pilot signal, etc. in the precoded and MIMO-encoded signal, and outputs the built transmission frame to the second modulator 485. For example, in the VSB system, a segment synchronous signal and a field synchronous signal are inserted in each transmission frame.

[91] The first modulator 480 modulates data outputted from the first frame builder 470 such that the data can be transmitted on a corresponding single carrier, and outputs the modulated data to the first transmitting unit 490. The second modulator 485 modulates data outputted from the second frame builder 475 such that the data can be transmitted on a corresponding single carrier, and outputs the modulated data to the second transmitting unit 495. For example, in the VSB system, the first modulator 480 and second modulator 485 modulate data of the respective transmission frames outputted from the first frame builder 470 and second frame builder 475 into VSB signals of an intermediate frequency band and output the modulated VSB signals to the first transmitting unit 490 and second transmitting unit 495, respectively.

[92] The first transmitting unit 490 and second transmitting unit 495 convert respective digital signals outputted from the first modulator 480 and second modulator 485 into analog signals and transmit the analog signals, respectively.

[93] FIG. 11 is a schematic block diagram of a signal reception apparatus according to one embodiment of the present invention. The embodiment of FIG. 11 may be included in a broadcast reception apparatus, etc.

[94] The embodiment of FIG. 11 comprises a receiving unit 600, synchronizer 610, demodulator 620, frame parser 630, MIMO decoder 640, deinterleaver 650, linear precoding decoder 660, symbol demapper 670, inner deinterleaver 680, inner decoder 690, outer deinterleaver 695, and outer decoder 697. The embodiment of FIG. 11 will be described centering around a signal processing process of the signal reception apparatus under the condition that the number of reception paths is not fixed.

[95] The receiving unit 600 down-converts a frequency band of a received radio frequency (RF) signal, converts the resulting analog signal into a digital signal and outputs the converted digital signal to the synchronizer 610. The synchronizer 610 acquires frequency-domain and time-domain synchronizations of the received signal outputted from the receiving unit 600 and outputs the resulting signal to the demodulator 620. For the acquisition of the frequency-domain synchronization, the synchronizer 610 may use frequency-domain offset results of data outputted from the demodulator 620.

[96] The demodulator 620 demodulates received data outputted from the synchronizer

610 and outputs the demodulated data to the frame parser 630. The demodulator 620 demodulates the received data in the reverse of a transmission scheme of a corresponding single carrier transmission system. For example, in the case where data is modulated and transmitted in a VSB scheme, the demodulator 620 demodulates the transmitted data in the VSB scheme. In this case, the demodulator 620 performs a carrier recovery, timing recovery, channel equalization, etc.

[97] The frame parser 630 parses a frame structure of a signal demodulated by the demodulator 620 to extract, therefrom, symbol data in a data period except a synchronous signal, pilot signal, etc., and outputs the extracted symbol data to the MIMO decoder 640.

[98] The MIMO decoder 640 receives and decodes the symbol data in the data period outputted from the frame parser 630, and outputs the resulting one data stream to the deinterleaver 650. The MIMO decoder 640 outputs one data stream by decoding the received data in a scheme corresponding to the encoding scheme of the MIMO encoder 170 of FIG. 1 which encodes data to be transmitted so that the data to be transmitted can be transmitted on a plurality of transmission antennas.

[99] The deinterleaver 650 deinterleaves the data stream outputted from the MIMO decoder 640 to restore the order of the symbol data of the data stream to one before being interleaved, and outputs the order-restored symbol data to the linear precoding decoder 660. The deinterleaver 650 restores the order of the data stream to the original one by deinterleaving the data stream in a scheme corresponding to the interleaving scheme of the interleaver 160 of FIG. 1.

[100] The linear precoding decoder 660 restores the original data from data dispersed to be robust to time- selective fading. The linear precoding decoder 660 restores the original data by performing an inverse process of the data dispersion process of the signal transmission apparatus.

[101] FIG. 12 is a block diagram schematically showing an example of the linear precoding decoder 660 according to one embodiment of the present invention. The linear precoding decoder 660 includes a serial/parallel converter 662, first decoder 664, and parallel/serial converter 666.

[102] The serial/parallel converter 662 converts input data into parallel data and outputs the converted parallel data to the first decoder 664. The first decoder 664 restores the original data from dispersed data by applying the parallel data to decoding matrixing, and outputs the restored data to the parallel/serial converter 666. A decoding matrix for performing the decoding is an inverse matrix of the encoding matrix of the signal transmission apparatus. For example, in the case where the signal transmission apparatus performs the encoding using the vanderMonde matrix as shown in FIG. 3, the first decoder 664 restores the dispersed data to the original data using an inverse matrix of the vanderMonde matrix.

[103] The parallel/serial converter 666 again converts parallel data outputted from the first decoder 664 into serial data and outputs the converted serial data to the symbol demapper 670.

[104] FIG. 13 is a block diagram schematically showing another example of the linear precoding decoder 660 according to one embodiment of the present invention. The linear precoding decoder 660 includes a serial/parallel converter 661, second decoder 663, and parallel/serial converter 665.

[105] The serial/parallel converter 661 converts input data into parallel data, and the parallel/serial converter 665 again converts parallel data received from the second decoder 663 into serial data. The second decoder 663 restores the original data dispersed into parallel data outputted from the serial/parallel converter 661 using Maximum Likelihood (ML) decoding.

[106] The second decoder 663 may be an ML decoder considering a transmission scheme of the signal transmission apparatus. In this case, the second decoder 663 restores the original data dispersed into received symbol data by ML-decoding the received symbol data correspondingly to the transmission scheme. That is, the ML decoder ML-decodes the received symbol data in consideration of an encoding rule of a transmitting stage.

[107] The symbol demapper 670 demaps the symbol data restored by the linear precoding decoder 660 to a bit stream of a corresponding symbol and outputs the demapped bit stream to the inner deinterleaver 680.

[108] The inner deinterleaver 680 performs an inverse process of the inner interleaving of the signal transmission apparatus with respect to the bit stream inputted thereto, and the inner decoder 690 is a decoder corresponding to the inner coder of the signal transmission apparatus, and decodes the deinterleaved data to correct an error included in the data. The outer deinterleaver 695 and the outer decoder 697 again perform the deinterleaving process and the error correction decoding process based on schemes corresponding to the outer interleaving and outer coding of the signal transmission apparatus, respectively.

[109] FIG. 14 is a schematic block diagram of a signal reception apparatus having a plurality of reception paths according to one embodiment of the present invention. For the convenience of description, the case where the number of reception paths is two will hereinafter be taken as an example.

[110] The embodiment of FIG. 14 comprises a first receiving unit 800, second receiving unit 805, first synchronizer 810, second synchronizer 815, first demodulator 820, second demodulator 825, first frame parser 830, second frame parser 835, MIMO decoder 840, deinterleaver 850, linear precoding decoder 860, symbol demapper 870, inner deinterleaving & decoding unit 880, outer deinterleaver 890, and outer decoder 895.

[I l l] The first receiving unit 800 receives an RF signal, down-converts a frequency band of the received RF signal, converts the resulting analog signal into a digital signal and outputs the converted digital signal to the first synchronizer 810. The second receiving unit 805 receives an RF signal, down-converts a frequency band of the received RF signal, converts the resulting analog signal into a digital signal and outputs the converted digital signal to the second synchronizer 815.

[112] The first synchronizer 810 acquires frequency-domain and time-domain synchronizations of the received signal outputted from the first receiving unit 800 and outputs the resulting signal to the first demodulator 820. The second synchronizer 815 acquires frequency-domain and time-domain synchronizations of the received signal outputted from the second receiving unit 805 and outputs the resulting signal to the second demodulator 825. At this time, for the acquisition of the frequency-domain synchronizations, the first synchronizer 810 and the second synchronizer 815 may use frequency-domain offset results of data outputted from the first demodulator 820 and second demodulator 825, respectively.

[113] The first demodulator 820 demodulates and equalizes received data outputted from the first synchronizer 810 and outputs the demodulated and equalized data to the first frame parser 830. The second demodulator 825 demodulates and equalizes received data outputted from the second synchronizer 815 and outputs the demodulated and equalized data to the second frame parser 835. For example, in a VSB system, each of the first and second demodulators 820 and 825 demodulates the received data in the reverse of a VSB modulation scheme and equalizes the demodulated data.

[114] The first frame parser 830 parses a frame structure of the data demodulated by the first demodulator 820 to extract, therefrom, symbol data in a data period except a synchronous signal, pilot signal, etc., and outputs the extracted symbol data to the MIMO decoder 840. The second frame parser 835 parses a frame structure of the data demodulated by the second demodulator 825 to extract, therefrom, symbol data in a data period except a synchronous signal, pilot signal, etc., and outputs the extracted symbol data to the MIMO decoder 840.

[115] The MIMO decoder 840 receives the data outputted respectively from the first frame parser 830 and second frame parser 835, decodes the received data in a scheme corresponding to the MIMO encoding scheme of the signal transmission apparatus and outputs the resulting one data stream.

[116] The subsequent signal processing process from the MIMO decoder 840 to the outer decoder 895 is the same as that described in FIG. 11.

[117] That is, the deinterleaver 850 deinterleaves the data stream outputted from the

MIMO decoder 840 in a scheme corresponding to the interleaving scheme of the signal transmission apparatus to restore the order of the symbol data of the data stream to the original one, and outputs the order-restored symbol data to the linear precoding decoder 860. That is, a convolution deinterleaver, block deinterleaver or the like is used as the deinterleaver 850 according to the type of the interleaver used in the signal transmission apparatus.

[118] The linear precoding decoder 860 restores the original data from data dispersed to be robust to time- selective fading. The linear precoding decoder 860 restores the original data by performing an inverse process of the data dispersion process of the signal transmission apparatus. To this end, the linear precoding decoder 860 includes a serial/parallel converter, a first decoder (or second decoder), and a parallel/serial converter.

[119] FIGs. 15 to 19 are views showing examples of a 2x2 code matrix for restoration of dispersed symbols according to one embodiment of the present invention. The code matrices of FIGs. 15 to 19 are applicable to the signal reception apparatus as shown in FIG. 14, and restore and output data dispersed into two data inputted to the decoder of the linear precoding decoder 860.

[120] The matrix of FIG. 15 is an example of a vanderMonde inverse matrix, which is a decoding matrix corresponding to the encoding matrix of FIG. 6.

[121] The matrix of FIG. 15 adds a first one of the two input data and a second one of the two input data to provide first output data, and adds the first input data rotated -45 degrees ( n 4 ) in phase and the second input data rotated -225 degrees (

5 π

4

) in phase to provide second output data. Then, the matrix of FIG. 15 scales each output data by dividing it by

4i

[122] The matrix of FIG. 16 is an example of a Hadamard inverse matrix, which is a decoding matrix corresponding to the encoding matrix of FIG. 7.

[123] The matrix of FIG. 16 adds a first one of the two input data and a second one of the two input data to provide first output data, and subtracts the second input data from the first input data to provide second output data. Then, the matrix of FIG. 16 scales each output data by dividing it by

4ϊ

[124] FIG. 17 shows another example of the dispersed data restoration code matrix applicable to FIG. 14 according to one embodiment of the present invention. The matrix of FIG. 17 is a decoding matrix corresponding to the encoding matrix of FIG. 8.

[125] The matrix of FIG. 17 adds a first one of the two input data rotated -45 degrees ( π 4 ) in phase and a second one of the two input data rotated -45 degrees ( π

4

) in phase to provide first output data, and subtracts the second input data rotated 45 degrees in phase from the first input data rotated 45 degrees in phase to provide second output data. Then, the matrix of FIG. 17 scales each output data by dividing it by

[126] FIG. 18 shows another example of the dispersed data restoration code matrix applicable to FIG. 14 according to one embodiment of the present invention. The matrix of FIG. 18 is a decoding matrix corresponding to the encoding matrix of FIG. 9. [127] The matrix of FIG. 18 adds a first one of the two input data multiplied by 0.5 to a second one of the two input data to provide first output data, and subtracts the second input data multiplied by 0.5 from the first input data to provide second output data. Then, the matrix of FIG. 18 scales each output data by dividing it by

1.25

[128] FIG. 19 shows another example of the dispersed data restoration code matrix applicable to FIG. 14 according to one embodiment of the present invention. The matrix of FIG. 19 is a decoding matrix corresponding to the encoding matrix of FIG. 10. In FIG. 19, '*' means a complex conjugate of input data.

[129] The matrix of FIG. 19 adds a first one of the two input data rotated -90 degrees ( π

^~ Y

) in phase and a complex conjugate of a second one of the two input data to provide first output data, and adds the first input data and the complex conjugate of the second input data rotated -90 degrees ( n

2

) in phase to provide second output data. Then, the matrix of FIG. 19 scales each output data by dividing it by

[130] The symbol demapper 870 demaps the symbol data restored by the linear precoding decoder 860 to a bit stream of a corresponding symbol and outputs the demapped bit stream to the inner deinterleaving & decoding unit 880.

[131] The inner deinterleaving & decoding unit 880 is a block corresponding to the inner interleaving & coding unit 420 of FIG. 5 with respect to the bit stream inputted thereto, and deinterleaves and decodes an input signal to correct an error included in data.

[132] In the case where the inner coding and the inner interleaving are together performed in a trellis coder as in a VSB system, which is an example of a single carrier transmission system, the inner coder and the inner interleaver can be depicted as the inner coding & interleaving unit 420, which is one block. Also, in this case, in the corresponding signal reception apparatus, the inner deinterleaver and the inner decoder can be together depicted like the inner deinterleaving & decoding unit 880.

[133] However, in a different single carrier transmission system in which the inner deinterleaving and the inner decoding are performed separately, the inner deinterleaver and the inner decoder can be depicted as separate blocks as shown in FIG. 11. That is, this configuration may be different according to different application examples of the transmission/reception system.

[134] The outer deinterleaver 890 and outer decoder 895 again perform the deinterleaving process and the error correction decoding process based on schemes corresponding to the outer interleaving and outer coding of the signal transmission apparatus, respectively.

[135] FIG. 20 is a schematic block diagram of another example of the signal transmission apparatus according to one embodiment of the present invention, and FIG. 21 is a schematic block diagram of another example of the signal reception apparatus according to one embodiment of the present invention.

[136] FIGs. 20 and 21 show examples applied to systems of a Single Input Single Output

(SISO) scheme, not the MIMO scheme.

[137] The signal transmission apparatus of FIG. 20 comprises an outer coder 1000, outer interleaver 1010, inner coder 1020, inner interleaver 1030, symbol mapper 1040, linear precoder 1050, interleaver 1060, frame builder 1070, SC modulator 1080, and transmitting unit 1090.

[138] The signal reception apparatus of FIG. 21 comprises a receiving unit 1100, synchronizer 1110, SC demodulator 1120, frame parser 1130, deinterleaver 1140, linear precoding decoder 1150, symbol demapper 1160, inner deinterleaver 1170, inner decoder 1180, outer deinterleaver 1190, and outer decoder 1195.

[139] The signal transmission apparatus and the signal reception apparatus of FIGs. 20 and 21 perform the same processing processes as those described in FIGs. 1 and 11, respectively, with exception of the MIMO encoding and the MIMO decoding in that they employ the SISO scheme, not the MIMO scheme.

[140] That is, in the signal transmission apparatus, symbol data, subjected to linear precoding and interleaving to be robust to time-selective fading of a channel, is inputted to the frame builder 1070, which then builds and outputs frame data based on the inputted symbol data.

[141] In the signal reception apparatus, symbol data parsed by the frame parser 1130 is provided to the deinterleaver 1140, so that it is subjected to an inverse process of the processing process of the signal transmission apparatus performed to enable symbol data to be robust to the time- selective fading of the channel.

[142] In the case where the inner coding and the inner interleaving are together performed, the inner coder and the inner interleaver can be depicted as an inner coding & interleaving unit which is one block. Also, in this case, in the corresponding signal reception apparatus, the inner deinterleaver and the inner decoder can be together depicted like an inner deinterleaving & decoding unit.

[143] FIG. 22 is a flowchart illustrating a signal transmission/reception method according to one embodiment of the present invention.

[144] A signal transmission apparatus precodes mapped symbol data to disperse the mapped symbol data into a plurality of output symbol data in a time domain (S 1200). Therefore, it is possible to reduce the probability for all information to be lost due to fading when a time-selective fading channel is experienced.

[145] Then, the signal transmission apparatus interleaves the precoded symbol data such that the symbol data dispersed into the output symbol data cannot be subject to the same time- selective fading (S 1210). A convolution interleaver, block interleaver or the like may be used for this interleaving and selected according to a given embodiment.

[146] The precoding to disperse the symbol data in the time domain and the interleaving are steps of processing data to be transmitted such that the data to be transmitted can be robust to time-selective fading of a channel.

[147] Then, the signal transmission apparatus MIMO-encodes the interleaved symbol data such that the interleaved symbol data can be transmitted through a plurality of antennas (S 1220). The number of the antennas may be the number of available data transmission paths. In the case where the MIMO encoding scheme is a spatial diversity scheme, data of the same information is transmitted along the respective paths. In the case where the MIMO encoding scheme is a spatial multiplexing scheme, different data are transmitted along the respective paths.

[148] Then, the signal transmission apparatus converts the encoded data into frames based on the number of the MIMO transmission paths, and modulates and transmits the converted frames (S 1230).

[149] On the other hand, a signal reception apparatus receives transmitted signals using a plurality of reception antennas and demodulates the received signals into frames, respectively (S 1240).

[150] Then, the signal reception apparatus parses data of the demodulated frames and decodes the parsed data in a scheme corresponding to the MIMO encoding scheme to obtain one symbol data stream (S 1250). Then, the signal reception apparatus dein- terleaves the decoded symbol data stream in the reverse of the interleaving scheme of the signal transmission apparatus to restore the order of the data stream to the original one (S 1260). Then, the signal reception apparatus decodes the data stream, order- restored at the deinterleaving step, in the reverse of the precoding scheme of the signal transmission apparatus to restore the original symbol data dispersed into the plurality of symbol data in the time domain (S 1270). [151] On the other hand, in the case where the present signal transmission/reception method is applied to a signal transmission/reception apparatus of the SISO scheme, not the MIMO scheme, the MIMO encoding step S 1220 and the MIMO decoding step S 1250 are not performed.

[152] The above-described signal transmission/reception method and signal transmission/ reception apparatus are not limited to the above-stated embodiments, and are applicable to all signal transmission/reception systems including a broadcasting or communication system.

[153] It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.

[154]

Claims

[1] A signal transmission apparatus comprising: a symbol mapper for mapping input data to symbol data based on a given transmission scheme; a precoder for precoding the mapped symbol data to disperse the mapped symbol data into two or more symbol data in a time domain; an interleaver for interleaving symbol data of an output data stream from the precoder according to a predetermined rule; and a modulator for modulating the interleaved data such that the interleaved data can be transmitted on a single carrier.

[2] The signal transmission apparatus according to claim 1, wherein the precoder comprises: a serial/parallel converter for converting input serial data into parallel data; an encoder for multiplying the parallel data by a predetermined encoding matrix to disperse the parallel data; and a parallel/serial converter for converting the dispersed parallel data into serial data.

[3] The signal transmission apparatus according to claim 2, wherein the encoding matrix is a vanderMonde matrix

the vanderMonde matrix

being expressed by the following equation when the number of output data is L which is a natural number and a matrix component θ is

with respect to k which is a natural number:

[4] The signal transmission apparatus according to claim 2, wherein the encoding matrix is a Hadamard matrix

H_t

, the Hadamard matrix

Ht being expressed by the following equation when the number of output data is L : 2 , where L is a natural number:

[5] The signal transmission apparatus according to claim 2, wherein the encoder, for dispersion of two input data into two output data, adds a first one of the two input data and a second one of the two input data rotated 45 degrees in phase to provide a first one of the two output data, adds the first input data and the second input data rotated 225 degrees in phase to provide a second one of the two output data, and scales each of the first and second output data by dividing it by

[6] The signal transmission apparatus according to claim 2, wherein the encoder, for dispersion of two input data into two output data, adds a first one of the two input data and a second one of the two input data to provide a first one of the two output data, subtracts the second input data from the first input data to provide a second one of the two output data, and scales each of the first and second output data by dividing it by

Λ/2

[7] The signal transmission apparatus according to claim 2, wherein the encoder, for dispersion of two input data into two output data, adds a first one of the two input data rotated 45 degrees in phase and a second one of the two input data rotated - 45 degrees in phase to provide a first one of the two output data, subtracts the second input data rotated -45 degrees in phase from the first input data rotated 45 degrees in phase to provide a second one of the two output data, and scales each of the first and second output data by dividing it by

4ϊ

[8] The signal transmission apparatus according to claim 2, wherein the encoder, for dispersion of two input data into two output data, adds a first one of the two input data multiplied by 0.5 to a second one of the two input data to provide a first one of the two output data, subtracts the second input data multiplied by 0.5 from the first input data to provide a second one of the two output data, and scales each of the first and second output data by dividing it by

[9] The signal transmission apparatus according to claim 2, wherein the encoder, for dispersion of two input data into two output data, adds a first one of the two input data rotated 90 degrees in phase and a second one of the two input data to provide a first one of the two output data, adds a complex conjugate of the first input data and a complex conjugate of the second input data rotated -90 degrees in phase to provide a second one of the two output data, and scales each of the first and second output data by dividing it by

[10] The signal transmission apparatus according to claim 1, further comprising a

Multi Input Multi Output (MIMO) encoder for MIMO-encoding the interleaved data such that the interleaved data can be transmitted through a plurality of antennas.

[11] A signal transmission method comprising: precoding symbol data mapped based on a given transmission scheme to disperse the mapped symbol data into two or more symbol data in a time domain; interleaving symbol data of a precoded data stream according to a predetermined rule; and modulating the interleaved data such that the interleaved data can be transmitted on a single carrier.

[12] The signal transmission method according to claim 11, further comprising

MIMO-encoding the interleaved data such that the interleaved data can be transmitted through a plurality of antennas.

[13] A signal reception apparatus comprising: a demodulator for demodulating data received on a single carrier; a deinterleaver for deinterleaving one symbol data stream demodulated, to restore an order of symbol data of the symbol data stream to an original one; a precoding decoder for restoring symbol data dispersed in a time domain from the order-restored symbol data; and a symbol demapper for demapping the restored symbol data to output bit data of a corresponding symbol.

[14] The signal reception apparatus according to claim 13, further comprising a

MIMO decoder for MIMO-decoding data demodulated after being received through a plurality of antennas, to output the one symbol data stream.

[15] The signal reception apparatus according to claim 13, wherein the precoding decoder comprises: a serial/parallel converter for converting input serial data into parallel data; a decoder for multiplying the parallel data by a predetermined decoding matrix to restore data dispersed into the parallel data in the time domain; and a parallel/serial converter for converting the restored parallel data into serial data.

[16] The signal reception apparatus according to claim 15, wherein the decoding matrix is an inverse matrix of a vanderMonde matrix.

[17] The signal reception apparatus according to claim 15, wherein the decoding matrix is an inverse matrix of a Hadamard matrix.

[18] The signal reception apparatus according to claim 15, wherein the decoder, for restoration of two output data dispersed into two input parallel data, adds a first one of the two input data and a second one of the two input data to provide a first one of the two output data, adds the first input data rotated -45 degrees in phase and the second input data rotated -225 degrees in phase to provide a second one of the two output data, and scales each of the first and second output data by dividing it by

[19] The signal reception apparatus according to claim 15, wherein the decoder, for restoration of two output data dispersed into two input parallel data, adds a first one of the two input data and a second one of the two input data to provide a first one of the two output data, subtracts the second input data from the first input data to provide a second one of the two output data, and scales each of the first and second output data by dividing it by

V2

[20] The signal reception apparatus according to claim 15, wherein the decoder, for restoration of two output data dispersed into two input parallel data, adds a first one of the two input data rotated -45 degrees in phase and a second one of the two input data rotated -45 degrees in phase to provide a first one of the two output data, subtracts the second input data rotated 45 degrees in phase from the first input data rotated 45 degrees in phase to provide a second one of the two output data, and scales each of the first and second output data by dividing it by

[21] The signal reception apparatus according to claim 15, wherein the decoder, for restoration of two output data dispersed into two input parallel data, adds a first one of the two input data multiplied by 0.5 to a second one of the two input data to provide a first one of the two output data, subtracts the second input data multiplied by 0.5 from the first input data to provide a second one of the two output data, and scales each of the first and second output data by dividing it by

1.25

[22] The signal reception apparatus according to claim 15, wherein the decoder, for restoration of two output data dispersed into two input parallel data, adds a first one of the two input data rotated -90 degrees in phase and a complex conjugate of a second one of the two input data to provide a first one of the two output data, adds the first input data and the complex conjugate of the second input data rotated -90 degrees in phase to provide a second one of the two output data, and scales each of the first and second output data by dividing it by

[23] The signal reception apparatus according to claim 13, wherein the precoding decoder comprises: a serial/parallel converter for converting input serial data into parallel data; a decoder for Maximum Likelihood (ML) -decoding the parallel data based on a transmission scheme to restore data dispersed into the parallel data in the time domain; and a parallel/serial converter for converting the restored parallel data into serial data. [24] A signal reception method comprising: demodulating data received on a single carrier; deinterleaving one symbol data stream demodulated, to restore an order of symbol data of the symbol data stream to an original one; restoring symbol data dispersed in a time domain from the order-restored symbol data; and demapping the restored symbol data to output bit data of a corresponding symbol. [25] The signal reception method according to claim 24, further comprising MIMO- decoding data demodulated after being received through a plurality of antennas, to output the one symbol data stream.