KR20050023855A - System and method for wireless communication - Google Patents

Abstract

PURPOSE: A wireless communication system and a communication method are provided to improve system performance and to reduce system complexity by encoding input data using complementary code keying. CONSTITUTION: A transmitter encodes input data using a first matrix and a phase transformation vector so that the encoded data has a complementary code property. A receiver decodes the received signal using second and third matrix corresponding to the first matrix. A bit repeater(202) repeats a first symbol from plural symbols corresponding to the data by the bit number corresponding to a length of a codeword. An encoder(200) generates the first matrix and calculates the rest symbols. A first adder(204) adds the outputs of the bit repeater and the encoder to output a first addition signal. A codeword serializer(206) serializes the output of the encoder and the first addition signal. A second adder adds the output of the codeword serializer and the phase transformation vector to output a second addition signal. A modulator(212) performs quadrature phase shift keying on the second addition signal. A wireless signal transmitter(220) transmits the modulated signal to the receiver.

Description

Wireless communication system and communication method {SYSTEM AND METHOD FOR WIRELESS COMMUNICATION}

TECHNICAL FIELD The present invention relates to a wireless communication system and method, and more particularly, to a wireless communication system and a communication method for simplifying a system while improving an average power to maximum power ratio.

Wireless LAN (LAN) is a technology that uses radio waves or light instead of wires from a hub to a subscriber terminal when constructing a network. Therefore, wireless LAN can be established in a relatively quick time network compared to wired LAN, and can communicate on the go using a notebook and a PC card without staying in a fixed desktop environment.

To date, wireless data communications have had systems with transmission rates of 1 Mbps or 2 Mbps using the Industrial Science Medical (ISM) band, but two high-speed communications standards have emerged for the purpose of multimedia wireless access. One is IEEE802.11b such as Bluetooth, and the other is IEEE802.11a using 5GHz band.

In the wireless communication system, an orthogonal frequency division multiplex (hereinafter, referred to as OFDM) scheme is adopted as a modulation scheme. In general, the OFDM method is a method of distributing and spreading information over a plurality of carriers, and is a frequency multiplexing method in which a receiver separates each subcarrier even when a spectrum overlaps using orthogonality among subcarriers.

In addition, in the OFDM scheme, since data is transmitted by loading serial data on N subcarriers, the period of the signal is increased by N times, thereby minimizing the interference between signals by the channel.

The OFDM method having the above characteristics is known as one of communication methods suitable for high-speed data transmission in that interference between symbols may be reduced in high-speed communication on a multipath channel. Accordingly, the OFDM scheme is widely applied to digital transmission technologies such as wireless local area networks, wireless asynchronous transmission modes, and the like, which seek high-speed data transmission.

However, in the OFDM scheme, when the subcarriers have the same phase, they have a very large maximum power. Accordingly, an amplifier having an output corresponding to the maximum power is required, thereby increasing the cost.

Accordingly, an object of the present invention is to provide a wireless communication system for improving the average power to maximum power ratio of a system and reducing the complexity of the system.

Another object of the present invention is to provide a communication method according to the above wireless communication system.

In order to achieve the above object, a transmitter of a wireless communication system according to the present invention encodes data input from the outside to have a complementary code property by a first matrix and a phase shift vector of a predetermined form, and modulates the encoded data. The receiver decodes the signal received from the transmitter by using a second matrix and a third matrix corresponding to the first matrix, and demodulates the decoded signal.

In addition, the bit repeater of the complementary code generator according to the present invention repeats one symbol of a plurality of symbols corresponding to data input from the outside a predetermined number of times, and the encoder generates a first matrix of a predetermined form, thereby generating one symbol. Calculates the first matrix and the generated first matrix, except that the first adder adds the output signal of the bit repeater and the output signal of the encoder, and the serializer serializes the output signal of the encoder and the output signal of the first adder. The second adder adds a predetermined phase shift vector to the signals arranged in series, and the output signal of the second adder has a complement code characteristic.

The wireless communication method according to the present invention encodes data input from the outside to have a complement code feature by a first matrix and a phase shift vector of a predetermined form, and a first step of receiving and modulating the coded data by quadrature phase shifting. And a second step of decoding the decoded signal using a second matrix and a third matrix corresponding to the first matrix, and demodulating the decoded signal.

Therefore, the present invention can improve the performance of the wireless communication system, and can improve the complexity of the system.

Hereinafter, an OFDM communication system and a communication method according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a block diagram schematically showing an OFDM system according to an embodiment of the present invention, and FIG. 2 is a block diagram showing a transmitter shown in FIG.

As shown in FIG. 1, an OFDM system according to an embodiment of the present invention converts an input signal to have a complementary code property and transmits a signal received from the transmitter 100 and the transmitter 100 that are transmitted in an OFDM scheme. The receiver 110 recovers using the maximum likelihood of the matrix.

Here, as shown in FIG. 2, the transmitter 100 includes a reference matrix coder 200, a bit repeater 202, a codeword serializer 206, a first adder 204, and a first phase shift vector. Unit 208, second adder 210, quadrature phase shift keying modulator (hereinafter referred to as QPSK modulator) 212, serial / parallel converter 214, inverse fast Inverse Fast Fourier Transform (hereinafter referred to as IFFT) 216, Digital / Analog Converter (hereinafter referred to as D / A Converter) 218, RF (Radio Frequency) Transmitter 220 and transmit antenna 222.

First, a plurality of bits of data to be transmitted are QPSK modulated. Therefore, the data is grouped into two bits and converted into a symbol having any one of 0 to 3 values and input to the transmitter 100. In the present invention, a case where five symbols corresponding to 10 bits of data are input to the transmitter 100 will be described as an example.

The reference matrix encoder 200 encodes four symbols among the five symbols input from the outside and outputs the encoded symbols to the codeword serializer 206. That is, the reference matrix encoder 200 generates a reference matrix (G _3), performs coding resulting from the operation of the reference matrix (G ₃₎ and generates four symbols.

Here, the reference matrix G ₃ has a 4 × 8 size, as shown in Equation 1, a first row in which 1 is repeated by the length of a codeword, and constant vectors representing 0 to 7 values as a digital counter. It consists of the 2nd thru | or 4th row which consists of. That is, the first row of the reference matrix G ₃ is '11111111', the second row is '00001111', the third row is '00110011', and the fourth row is '01010101'. Therefore, the first column of the second row to the fourth row has a decimal value of '0' for the bit, the second column of '1', the third column of '2', the fourth column of '3', The fifth column is '4', the sixth column is '5', the seventh column is '6', and the eighth column is '7'.

In this case, the codeword means a value output from the reference matrix encoder 200. That is, when the calculation is to be performed with the reference matrix encoder 200, the input vector input to the reference matrix encoder 200 should have the same size as the reference matrix G ₃ generated by the reference matrix encoder 200. When an input vector, a reference matrix, and an operation are performed, a predetermined code equal to the size of a column of the reference matrix G ₃ is output from the reference matrix encoder 200, which is collectively referred to as a codeword.

In addition, four symbols to be input In this case, the reference matrix encoder 200 calculates the four symbols and the reference matrix G ₃ having the above configuration, and the codeword c 'according to the operation result is expressed by Equation 2 below. At this time, φ ₁ to φ ₄ have any one of 0 to 3.

If you reverse the matrix order of the signal c 'as shown in Equation 2, add one of the phase shift vectors as shown in Equation 3, and then perform a complex conversion in the counterclockwise direction, Complementary Code Keying (hereinafter referred to as CCK) type 8-bit codeword is completely the same.

In general, the 8-bit codeword of the CCK scheme is shown in Equation 4. That is, the 8-bit codeword value of the CCK method taking the exponential function has any one of {1, -1, j, -j}.

here, To Is a value representing any one of QPSK-modulated phases by grouping binary input data by two bits, and is one of 0, π / 2, π, and 3π / 2.

Among the three phase shift vectors shown in Equation 3, a phase shift vector to be completely equal to the 8-bit codeword of the CCK method of Equation 4 in addition to the codeword of Equation 2 is [00020020]. However, all of the codewords generated by adding the phase shift vectors other than the phase shift vector to Equation 2 also have a complementary code property.

On the other hand, the reference matrix (G ₃ ) has a size of 4 × 8 but when the number of data bits input to increase the data rate is increased, the reference matrix encoder 200 is a reference matrix (G ₃ ) and 0 and 1 vector Can be used to create a matrix of extended size.

That is, the reference matrix encoder 200 may generate an extended matrix G ₄ having a size of 5 × 10 by using two reference matrices G ₃ , 0 vectors, and 1 vectors as shown in Equation 5. have.

As shown in Equation 5, the matrix G _{4 in} which the reference matrix G ₃ is extended has 0 repeated in the first row, the first to the eighth columns, in which 1 is repeated by the codeword length, and ninth. The second row, which repeats 1 to columns 16 through 16, and the third to fifth rows, which are configured by repeating a plurality of vectors representing 0 to 7 values like a digital counter twice. That is, the first row of the matrix G ₄ where the reference matrix G ₃ is extended is '1111111111111111', the second row is '0000000011111111', the third row is '0000111100001111', and the fourth row is '0011001100110011'. , Fifth row is '0101010101010101'.

As such, the reference matrix encoder 200 may generate an extended form of the matrix using the reference matrix G ₃ as the number of bits of the data input to the transmitter, that is, the number of symbols increases.

The bit repeater 202 repeats the remaining one of the five symbols by the codeword length. For example, assuming that a symbol value input to the bit repeater 202 is '3', the bit repeater 202 outputs a bit repetition signal S2 of 3 times 8 times.

The first adder 204 code-sequences the first adder signal S4 obtained by adding the operation signal S1 output from the reference matrix encoder 200 and the bit repetition signal S2 output from the bit repeater 202. Output to enumerator 206.

The codeword serial sequencer 206 lists the serial signal S4 by serially arranging the operation signal S1 input from the reference matrix encoder 200 and the addition signal S3 input from the first adder 204. Output At this time, the serial sequence signal S4 output from the codeword serial sequencer 206 has a size of 1 × 16.

The second adder 210 adds a serial sequence signal S4 input from the codeword serializer 206 and a predetermined phase shift vector input from the first phase conversion vector unit 208, and then adds the second adder signal S5. ) Here, as shown in Equation 6, the first phase shift vector unit 208 stores 12 preset phase shift vectors.

[0002002000022202], [0002000200202202],

[0002020000022022], [0000022000220202],

[0002020000200222], [0000022002020022],

[0002002002000222], [0002000202002022],

[0000002202200202], [0000020202200022],

[0000020200222002], [0000002202022002]

As such, the second adder 210 adds any one of the phase shift vectors as shown in Equation 6 to the serial sequence signal S4 input from the codeword serial sequencer 206 to obtain the second add signal S5. Is output to the QPSK modulator 212. At this time, the second addition signal S5 output from the second adder 210 is the same as the 8-bit codeword of the CCK scheme shown in Equation (4). Accordingly, the second adder signal S5 in the second adder 210 has a complement code characteristic.

In addition, since the minimum distance between codes of the second addition signal S5 output from the second adder 210 increases, an error correction capability SER is improved as shown in FIG. 3.

3 is a graph showing a change in error correction capability of a communication system using a CCK scheme according to an embodiment of the present invention, Figure 4 is a graph showing the PAPR of the input data by the OFDM system according to the present invention.

As shown in Figure 3, (a) is a graph showing the error correction capability of the communication system not using the CCK method, (b) is a graph showing the error correction capability of the communication system using the CCK method according to the prior art. (C) is a graph showing the error correction capability of the communication system using the CCK scheme according to the present invention.

Therefore, as shown in the graph (c), the communication system using the CCK scheme according to the present invention can be seen that the signal-to-noise ratio (SNR) is improved by about 3 dB, and thus the error correction capability (SER) is improved. .

Meanwhile, the QPSK modulator 212 performs QPSK modulation by carrying the second addition signal S5 input from the second adder 210 to 64 subcarriers, and outputs the QPSK modulated signal to the serial / parallel converter 214. )

The serial / parallel converter 214 outputs the QPSK modulated signals in parallel, and the IFFT unit 216 converts the QPSK modulated signals output in parallel by inverse fast Fourier transform to convert the modulated signals in the frequency domain into the modulated signals in the time domain. Convert.

The D / A converter 218 converts the inverse fast Fourier transformed modulated signal into an analog signal, and the RF transmitter 220 converts the modulated signal converted into an analog signal into a radio frequency signal to convert the transmit antenna 222. Send it through.

As described above, the transmitter 100 of the communication system according to an embodiment of the present invention generates a codeword having a complementary code property by the reference matrix G ₃ and a preset phase shift vector.

Therefore, when the input data is transmitted by the conventional OFDM communication system using 64 subcarriers, the PAPR becomes 18 dB, but according to the OFDM communication system according to the present invention, the PAPR is reduced by 9 dB. Therefore, the present invention can reduce the PAPR by 9 dB as compared with the conventional art.

That is, as shown in Figure 4, the PAPR by the OFDM communication system according to the present invention is 9dB, it can be seen that reduced by about 9dB compared to the conventional 18dB.

The receiver 110 for receiving and restoring a signal transmitted from the transmitter 100 configured and operated as described above will now be described in detail.

5 is a block diagram illustrating a configuration of a receiver of the OFDM system shown in FIG. 1.

As shown in FIG. 5, the receiver 110 of the OFDM system according to the present invention includes a reception antenna 500, an RF receiver 502, an A / D converter 504, and a fast Fourier transform unit (hereinafter, referred to as an FFT unit). 506, bottle / serial transform unit 508, second phase shift vector unit 510, subtractor 512, first correlation receiver 514, second correlation receiver 516, QPSK demodulator 520 And phase comparator 518.

The RF receiver 502 converts a radio frequency signal received through the reception antenna 500 into an intermediate frequency signal, and the A / D converter 504 converts the intermediate frequency signal into a digital signal. The FFT unit 506 converts the digital signal input from the A / D converter 504 into the fast / fourier transform unit 508 and outputs the parallel / serial converter 508. The parallel / serial converter 508 converts the fast Fourier transformed signal. Output in serial.

The second phase shift vector unit 510 generates a phase shift vector as shown in Equation 6 and phase shift added to the output signal of the codeword serializer 206 in the transmitter 100 among the generated phase shift vectors. A phase shift vector equal to the vector is output to the subtractor 512.

The subtractor 512 subtracts the phase shift vector output from the second phase shift vector unit 510 from the signals output in series from the parallel / serial transform unit 508, and thereby the first correlation receiver 514 and the second correlation receiver. Output to (516).

The first correlation receiver 514 decodes four input symbols on 64 subcarriers, and the second correlation receiver 516 decodes one input symbol.

That is, the first correlation receiver 514 generates a first Hadamard matrix having a predetermined size, decodes four input symbols by calculating a signal input from the subtractor 512 and the generated Hadamard matrix. In this case, the first Hadamard matrix H ₃ generated by the first correlation receiver 514 is generated by the general Hadamard matrix format as shown in Equation (7).

Here, m denotes the size of the Hadamard matrix, I denotes a square matrix, Q denotes an array value, and since the present invention performs QPSK modulation and demodulation, Q is 4.

That is, the first Hadamard matrix H ₃ is represented by Equation 8.

H ₂ is represented by Equation (9).

Accordingly, the first correlation receiver 514 decodes four symbols by calculating the signal input from the first subtractor 512 and the first Hadamard matrix H ₃ having the size of 8 × 64.

Meanwhile, the second correlation receiver 516 generates a second Hadamard matrix H ₁ having a size of 2 × 4 in Equation 10, and a signal input from the first subtractor 512 and the generated second Hadamard. Calculate the matrix H ₁ .

The second Hadamard matrix H ₁ is a basic matrix of the Hamadad matrix, and the first Hadamard matrix H ₃ is generated by substituting the second Hadamard matrix H _{1 in} Equation 7. That is, the first Hadamard matrix H ₃ is generated as the second Hadamard matrix H ₁ is expanded.

As such, the reason why the second correlation receiver 516 can decode the symbol using the second Hadamard matrix H ₁ having a smaller size than the first Hadamard matrix H ₃ will be described in detail as follows.

First, since the size of the first Hadamard matrix H ₃ is too large and complicated, the first Hadamard matrix H ₃ will be described by comparing the H ₂ shown in Equation 9 with the second Hadamard matrix H _{1 due} to the scalability of the Hadamard matrix.

If there is an H ₂ matrix shown in Equation 9, and the input sequence is [abcd], the input sequence corresponds to any one of {1, -1, j, -j}. Further, let's say the H2 matrix is a k-th index, that is, the k-th column is the maximum value assumed in each comes out, the heat value of the k-th index of the matrix H ₂ C1, C2, C3, and C4.

Here, when the input sequence [abcd] is multiplied by the kth index column [C1 C2 C3 C4], the value is the maximum value, which is one of {4, -4,4j, -4j} (aC1 + bC2 + cC3 +). dC4 = maximum value {4, -4,4j, -4,}. In this case, in order to have the maximum value as described above, the value of each term is equal to one of {1, -1, j, -j} (aC1 = bC2 = cC3 = dC4 ∈ {1, -1, j, -j}).

On the other hand, in the above input sequence [abcd], if applied to the second Hadamard matrix H _{1 with} only the first two bits [ab] as follows.

Second Hadamard matrix Let assume the maximum value comes from the n-th index of (H _1), the second Hadamard matrix to the n-th column value of the index (H ₁₎ L1, and L2. Here, if the input sequence [ab] is multiplied by the nth index column [L1 L2], the value is one of {2, -2,2j, -2j} as a maximum value (aL1 + bL2 = maximum value ∈ {2 , -2,2j, -2j}). In this case, in order for the product of the input sequence and the nth index column to have the maximum value, the values of each term must all be equal to one of {1, -1, j, -j} (aL1 = bL2 ∈ {1, -1, j,- j}).

Therefore, the value of the k-th index column of the H ₂ matrix and the value of the n-th index column of the second Hadamard matrix H ₁ are the same (C1 = L1, C2 = L2). Therefore, the second correlation receiver 516 generating a second Hadamard matrix H ₁ having a size of 2 × 4 can also decode the symbol.

In addition, the phase comparator 518 compares the phase of the maximum value for the four symbols obtained by the first correlation receiver 514 with the phase of the maximum value for the one symbol obtained by the second correlation receiver 516 and phase difference thereof. Decode one symbol by.

The QPSK demodulator 520 receives four symbol signals decoded from the first correlation receiver 514 and one symbol signal decoded from the phase comparator 518, and quadrature phase shifts the demodulated input signal to the original signal. 5 symbol signals are recovered.

When the number of symbols input to the transmitter 100 described above is increased, the number of bit repeaters may be increased by the number of symbols to be encoded to encode the input symbols to have a complementary code property. That is, when the number of input symbols increases to six, two bit repeaters are formed, four input symbols are input to the reference matrix encoder 200, and the remaining two input symbols are input to the two bit repeaters, respectively.

On the other hand, when the number of symbols input to the transmitter 100 is increased, the receiver 110 increases the number of second correlation receivers by the number of increased symbols to decode the input symbols encoded to have a complementary code property. That is, when the number of input symbols increases to six, two second correlation receivers 516 are formed, and four symbols coded to have a complementary code property are demodulated in the first correlation receiver 514, and the remaining ones. Two symbols are respectively input to two second correlation receivers 516 and encoded.

In addition, when the number of symbols input to the transmitter 100 increases, the bit repeater may be operated by the increased number of symbols using the counter. When the number of symbols input to the transmitter 100 increases, the receiver 110 may increase the number of symbols. The second correlation receiver can be operated by an increased number of symbols.

The communication method of the OFDM communication system according to the present invention configured and operated as described above will be described in detail with reference to the accompanying drawings.

6 is a flowchart illustrating a radio signal transmission operation of an OFDM communication system according to the present invention, and FIG. 7 is a flowchart illustrating the detailed steps of encoding the input data of FIG. 6 to have a complementary code property. .

First, the transmitter 100 encodes a symbol corresponding to data input from the outside to have a complementary code property (S600), and performs QPSK modulation on the encoded signal (S610).

Subsequently, the transmitter 100 converts the QPSK modulated signal into a radio frequency signal and transmits the signal to the receiver 110 (S620).

Here, the step of encoding a symbol corresponding to data input from the outside to have a complementary code property will be described in more detail with reference to FIG. 7.

The bit repeater 202 of the transmitter 100 repeats the first symbol that is the last symbol among symbols corresponding to the input data by the codeword length (S700). Standard matrix encoder 200 calculates a reference matrix (G ₃₎ and generating the remaining symbols except for the first symbol of generating a reference matrix (G _3), such as the equation (1), and symbols (S710).

The first adder 204 adds the signal repeated by the codeword length by the bit iterator 202 and the signal calculated by the reference matrix encoder 200 (S720), and the codeword serializer 206 adds the reference matrix. The signal calculated by the encoder 200 and the signal added by the first adder 204 are listed in series (S730).

Subsequently, the second adder 210 adds a phase shift vector of any one of the phase shift vectors stored in the first phase shift vector unit 208 to the signals arranged in series (S740). At this time, the signal output by the adding operation of the second adder 210 has a complement code characteristic.

8 is a flowchart for explaining a radio signal reception operation of the OFDM communication system of the present invention.

First, the RF receiver 502 of the receiver 110 converts a signal received through the receiving antenna 500 into an intermediate frequency signal (S800), and the subtractor 512 subtracts a phase shift vector from the intermediate frequency signal ( S810).

Subsequently, the first correlation receiver 514 and the second correlation receiver 516 generate first and second Hadamard matrices H _{3 and} H ₁ , which are matrices corresponding to the reference matrix G ₃ , respectively (S820). ). The first correlation receiver 514 decodes a signal obtained by subtracting the phase shift vector, that is, a subtracted signal corresponding to a portion of the input symbol by the first Hadamard matrix H ₃ (S830), and the second correlation receiver 516. ) Decodes the subtracted signal corresponding to the remaining portion except for a portion of the input symbol by the second Hadamard matrix H ₁ (S840).

The phase comparator 518 has the maximum amplitude of the signal decoded by the first Hadamard matrix H ₃ and the maximum of the signal decoded by the second Hadamard matrix H ₁ in steps S830 and S840 above. The phases of the amplitudes are compared (S850), and the QPSK demodulator 520 QPSK demodulates the signal corresponding to the phase difference according to the comparison result of the phase comparator 518 and the signal decoded by the first Hadamard matrix H ₃ . (S860). Here, the signal demodulated by the QPSK demodulator 520 is the same signal as the symbol input to the transmitter 100.

As described above, the wireless communication system and the communication method according to the present invention encode the input data to have a complementary code property by a predetermined reference matrix and a phase shift vector generated by the reference matrix encoder, Decodes the data encoded by the Hadamard matrix corresponding to the reference matrix formed by. Here, the correlation receiver includes a first correlation receiver of 8x64 size and a second correlation receiver of 2x4 size for the CCK scheme.

Therefore, in the present invention, since the input data is encoded to have a complementary code property, the minimum distance between codes is increased to improve error correction capability, and the average power to maximum power ratio, which is the biggest problem of the OFDM scheme, can be improved. There is an effect that can improve the performance of the wireless communication system.

In addition, since the present invention uses a second correlation receiver having a smaller size than the first correlation receiver by using the scalability of the Hadamard matrix, the complexity of the receiver can be reduced.

In addition, when the input data is increased, the present invention has an effect of encoding the increased input data to have a complementary code property as the number of bit repeaters is increased or the operation of the bit repeaters is repeated.

In addition, the present invention is an effect that can be decoded as the number of the second correlation receiver or the number of operations of the second correlation receiver is increased even if the input data is increased to increase the signal transmitted from the transmitter There is also.

While the invention has been described with reference to the examples, those skilled in the art may variously modify and change the invention without departing from the spirit and scope of the invention as set forth in the claims below. You will understand.

1 is a block diagram schematically illustrating an OFDM system according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating a transmitter shown in FIG. 1.

3 is a graph illustrating a change in error correction capability of a communication system using a CCK scheme according to an embodiment of the present invention.

4 is a graph showing PAPR of input data by an OFDM system according to the present invention.

5 is a block diagram illustrating a configuration of a receiver of the OFDM system shown in FIG. 1.

6 is a flowchart illustrating a radio signal transmission operation of an OFDM communication system according to the present invention.

FIG. 7 is a flowchart for explaining a detailed step of encoding the input data of FIG. 6 to have a complementary code property.

8 is a flowchart for explaining a radio signal reception operation of the OFDM communication system of the present invention.

Explanation of symbols on the main parts of the drawings

100: transmitter 110: receiver

200: reference matrix encoder 202: bit repeater

208: First Phase Conversion Vector Part 212: QPSK Modulator

510: second phase shift vector unit 514: first correlation receiver

516: second correlation receiver 520: QPSK demodulator

518: phase comparator

Claims (24)

A transmitter for encoding data input from the outside so as to have a complementary code property by using a first matrix and a phase conversion vector of a predetermined form, and modulating and transmitting the encoded data; And And a receiver for decoding the signal received from the transmitter using a second matrix and a third matrix corresponding to the first matrix, and demodulating the decoded signal. The method of claim 1, wherein the transmitter A bit repeater for repeating a first symbol among a plurality of symbols corresponding to the data by the number of bits corresponding to the transmission codeword length; An encoder for generating the first matrix and calculating remaining symbols except for the first symbol among the generated first matrix and the plurality of symbols; A first adder which adds an output signal of the bit repeater and an output signal of the encoder to output a first addition signal; A codeword serial sequencer for serially arranging the output signal of the encoder and the first addition signal; A second adder for adding the output signal of the codeword serializer and the phase shift vector to output a second addition signal; A modulator for modulating the second added signal by a quadrature phase shifter; And And a radio signal transmitter for converting the modulated signal into a radio signal and transmitting the radio signal to the receiver. 3. The first matrix of claim 2, wherein the first matrix is a first row in which 1 is repeated in correspondence with the same column size as the signal output from the encoder, and each bit is incremented by 1 bit so that each column has a value of 0 to 7 in decimal. And a second row to a fourth row. The method of claim 3, wherein the first matrix is Wireless communication system, characterized in that. The method of claim 2, wherein the phase shift vector is [0002002000022202], [0002000200202202], [0002020000022022], [0000022000220202], [0002020000200222], [0000022002020022], [0002002002000222], [0002000202002022], [0000002202200202], [0000020202200022], [0000020200222002], [0000002202022002] any one of a wireless communication system. 3. The wireless communication system of claim 2, wherein the number of bit repeaters increases to correspond to an increasing number of symbols. The wireless communication system of claim 2, wherein the number of operations of the bit repeater is repeated according to an increase in the number of symbols. The method of claim 2, wherein the receiver A radio signal receiver for receiving a radio signal from the radio signal transmitter; A subtractor configured to subtract the phase shift vector from the received radio signal to output a subtracted signal; A first decoder for generating the second matrix and decoding a portion of the subtracted signal corresponding to the symbols except the first symbol by the generated second matrix; A second decoder for generating the third matrix and decoding a portion of the subtracted signal corresponding to the first symbol by the generated third matrix; And A phase comparator for comparing a phase difference between the maximum amplitude of the signal decoded by the first decoder and the maximum amplitude of the signal decoded by the second decoder; And And a demodulator for quadrature demodulating the output signal of the first decoder and the output signal of the phase comparator. The method of claim 8, wherein the second matrix is And m is 3 and Q is 4. The method of claim 9, wherein the second matrix is And H2 is Wireless communication system characterized in that. The method of claim 8, wherein the third matrix is Wireless communication system, characterized in that. The wireless communication system according to claim 8, wherein the number of the second decoders increases to correspond to the increasing number of symbols. The wireless communication system of claim 8, wherein the number of operations of the second decoder is repeated according to an increase in the number of symbols. A bit repeater for repeating one symbol of a plurality of symbols corresponding to data input from the outside a predetermined number of times; An encoder for generating a first matrix of a predetermined form and calculating and encoding the remaining symbols except for the one symbol and the generated first matrix; A first adder for adding the output signal of the bit repeater and the output signal of the encoder; A serial sequencer for serially arranging the output signal of the encoder and the output signal of the first adder; And A second adder is added by adding a predetermined phase shift vector to the serially arranged signals, And an output signal of the second adder has a complement code characteristic. The method of claim 14, wherein the first matrix is Maintenance code generation device, characterized in that. The method of claim 14, wherein the phase shift vector is [0002002000022202], [0002000200202202], [0002020000022022], [0000022000220202], [0002020000200222], [0000022002020022], [0002002002000222], [0002000202002022], [0000002202200202], [0000020202200022], [0000020200222002], [0000002202022002] any one of the maintenance code generating apparatus. A first step of encoding data input from the outside so as to have a complementary code feature by a first matrix and a phase transform vector of a predetermined form, and performing quadrature phase modulation on the encoded data; And Receiving a modulated signal of the quadrature phase, decoding the received signal using a second matrix and a third matrix corresponding to a first matrix, and then performing a second demodulation of the quadrature on the quadrature Wireless communication method comprising a. 18. The method of claim 17, wherein the first step is Converting the data input from the outside into a signal having a complementary code property; A quadrature phase modulated signal having the complementary code property; And And converting the modulated signal into a radio frequency signal for transmission. 19. The method of claim 18, wherein converting the data input from the outside into a signal having a complementary code property Repeating a first symbol among a plurality of symbols corresponding to the data by the number of bits corresponding to a transmission codeword length; Generating the first matrix and calculating remaining symbols except for the first symbol among the generated first matrix and the plurality of symbols; Adding the computed signal and the repeated signal by the number of bits of the transmission codeword length; Arranging the calculated signal and the added signal in series; And Adding the phase shift vector to the serially listed signals. 18. The method of claim 17, wherein the first matrix is Wireless communication method characterized in that. The method of claim 17, wherein the phase shift vector is [0002002000022202], [0002000200202202], [0002020000022022], [0000022000220202], [0002020000200222], [0000022002020022], [0002002002000222], [0002000202002022], [0000002202200202], [0000020202200022], [0000020200222002], [0000002202022002] any one of the wireless communication method. 18. The method of claim 17, wherein the second step is Converting the received signal into an intermediate frequency signal; Subtracting the phase shift vector from the intermediate frequency signal; Generating the second matrix and the third matrix; Decode the subtracted signal corresponding to a portion of the plurality of symbols corresponding to the input data by the second matrix, and convert the subtracted signal corresponding to the remaining portion except for the portion of the plurality of symbols to the third matrix; Decrypting by; Comparing the phase of the maximum amplitude of the signal decoded by the second matrix with the maximum amplitude of the signal decoded by the third matrix; And And quadrature demodulating the signal decoded by the second matrix and a signal corresponding to the phase difference according to the comparison result. The method of claim 22, wherein the second matrix is H ₂ is Wireless communication method characterized in that. The method of claim 22, wherein the third matrix is Wireless communication method characterized in that.