Wireless communication systems and wireless communication methods

Abstract

To provide a wireless communication system and a wireless communication method that enhance error correction capability for spread spectrum communication with orthogonal coding in which no known signal is inserted in a data frame, improve communication accurately-arriving performance, and increase communication speed.SOLUTION: In a wireless communication system and a wireless communication method, a transmitting device includes a spread processing unit 103 that performs spread spectrum using fully orthogonal coding on a signal to be transmitted, and a receiving device includes a de-spreading processing unit 105 that performs a cross-correlation operation with a fully orthogonal coding pattern on the spread spectrum signal and searches for the value of a peak of power and the location of the peak, a noise calculation unit 106 that estimates the noise power from the value of the peak, and a demapping unit 107 that performs weighting for a result of the correlation operation using the estimated noise power.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a wireless communication system, and more particularly to a wireless communication system and a wireless communication method that can estimate noise power without using known signals such as pilot signals. [Background technology]

[0002] [Conventional technology] Generally, in wireless communication systems, known signals such as pilot signals are periodically inserted to estimate preambles and propagation paths for purposes such as synchronous acquisition and AFC (Auto Frequency Control).

[0003] Conventional techniques have involved estimating noise power from the known signals mentioned above, and then, during data symbol demodulation, calculating a bit LLR (Log Likelihood Ratio) weighted by the estimated noise power to improve error correction capability.

[0004] [Related technologies] Furthermore, related prior art includes Japanese Patent Publication No. 2014-036397, "Normalization Circuit for OFDM Receiver" (Patent Document 1), and Japanese Patent Publication No. 2014-236337, "OFDM Receiver" (Patent Document 2).

[0005] Patent Document 1 shows a normalization circuit for an OFDM receiver in which the normalized output of the received signal fluctuates based on the average value of the noise, rather than the absolute amount of noise. Patent Document 2 describes an OFDM receiver that can calculate an appropriate likelihood even while being affected by noise and interference waves. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2014-036397 [Patent Document 2] Japanese Patent Publication No. 2014-236337

Summary of the Invention

Problems to be Solved by the Invention

[0007] However, for the technology of inserting conventional known signals, in communication standards such as MIL-STD-188-110D, Walsh codes, which are complete orthogonal codes in spread-spectrum communication, are adopted. Also, no known signal is inserted into the data frame. In particular, although it is necessary to calculate the noise power in real time to improve the error correction ability in dynamic characteristics, the conventional technology has a problem that it cannot cope with this.

[0008] In addition, Patent Documents 1 and 2 do not describe a configuration for improving the error correction ability for spread-spectrum communication using orthogonal codes into which no known signal is inserted into the data frame.

[0009] The present invention has been made in view of the above circumstances, and aims to provide a wireless communication system and a wireless communication method that improve the error correction ability for spread-spectrum communication by orthogonal coding without inserting a known signal into the data frame, and realize improvement in communication reliability and acceleration of communication.

Means for Solving the Problems

[0010] The present invention for solving the problems of the above conventional example is a wireless communication system including a transmission device and a reception device. The transmission device includes a spreading processing unit that performs spread-spectrum using complete orthogonal coding on a signal to be transmitted. The reception device includes a despreading processing unit that performs a cross-correlation operation with a complete orthogonal coding pattern on the spread-spectrum signal and searches for the value of the peak of the power and the position of the peak, a noise calculation unit that estimates the noise power from the peak value, and a demapping unit that performs weighting with the estimated noise power on the result of the correlation operation. The despreading processing unit includes a correlation calculation unit that performs a correlation calculation between the received signal and a reference signal for all code patterns for the received signal for each data symbol, and a peak detection unit that searches for the peak value and position where the power is maximum in a specific section, and determines the value of each code pattern at the position of the peak as the despreading result. The noise calculation unit estimates the noise power for each data symbol, and the demapping unit calculates the bit log-likelihood ratio using the despreading result and the noise power for each data symbol. It is characterized by this. [[ID=!]]

[0012] The present invention is characterized in that, in the above wireless communication system, the despreading processing unit includes a RAKE combining unit that searches for the peak values and peak positions for a plurality of power peaks and combines the searched peak values of the plurality of peaks.

[0013] The present invention is a wireless communication method between a transmitting device and a receiving device, wherein the transmitting device performs spectrum spreading on a signal to be transmitted using perfect orthogonal coding, and the receiving device performs a cross-correlation operation with a perfect orthogonal coding pattern on the spectrum-spread signal, searches for the peak value and the peak position of the power peak, estimates the noise power from the peak value, and weights the result of the correlation operation with the estimated noise power. This process involves performing a correlation calculation between the received signal and a reference signal for all code patterns corresponding to that received signal, for each data symbol; searching for the peak value and location where the power is maximum in a specific interval; determining the value of each code pattern at that peak location as a despreading result; estimating the noise power for each data symbol; and calculating the bit log-likelihood ratio using the despreading result and the noise power for each data symbol. It is characterized by this.

[0014] The present invention is characterized in that, in the above wireless communication method, the receiving device searches for the peak value and the peak position for a plurality of power peaks and combines the searched peak values of the plurality of peaks.

Effect of the Invention

[0015] According to the present invention, the transmitting device includes a spreading processing unit that performs spectrum spreading on a signal to be transmitted using perfect orthogonal coding, the receiving device performs a cross-correlation operation with a perfect orthogonal coding pattern on the spectrum-spread signal, a despreading processing unit that searches for the peak value and the peak position of the power peak, a noise calculation unit that estimates the noise power from the peak value, and a demapping unit that weights the result of the correlation operation with the estimated noise power. The despreading processing unit includes a correlation calculation unit that performs a correlation calculation between the received signal and a reference signal for all code patterns for the received signal for each data symbol, and a peak detection unit that searches for the peak value and position where the power is maximum in a specific section, and determines the value of each code pattern at the position of the peak as the despreading result. The noise calculation unit estimates the noise power for each data symbol, and the demapping unit calculates the bit log-likelihood ratio using the despreading result and the noise power for each data symbol. Since it is a wireless communication system, it has the effect of improving the error correction ability for spectrum spreading communication by orthogonal coding in which no known signal is inserted into the data frame, improving the reliability of communication, and further realizing high-speed communication.

Brief Description of the Drawings

[0016] [Figure 1] It is a configuration block diagram of a first system. [Figure 2] It is a diagram showing an example of a Walsh code for 2-bit transmission. [Figure 3] This figure shows an example of a 4-bit transmission Walsh code. [Figure 4] This is a block diagram of the configuration of the dediffusion processing unit of the first system. [Figure 5] This is an explanatory diagram showing the correlated output image in the absence of noise. [Figure 6] This is an explanatory diagram showing the correlated output image in the presence of noise. [Figure 7] This is a block diagram of the second system configuration. [Figure 8] This is a block diagram of the configuration of the dediffusion processing unit of the second system. [Figure 9] This is an explanatory diagram showing the correlated output image when multipath is present. [Figure 10] This is a block diagram of the RAKE synthesis section of the second system. [Modes for carrying out the invention]

[0017] Embodiments of the present invention will be described with reference to the drawings. [Summary of the Embodiment] The wireless communication system according to an embodiment of the present invention (this system) includes a transmitting device equipped with a spreading spectrum processing unit that performs spreading spectrum using fully orthogonal coding on the signal to be transmitted, and a receiving device equipped with a despreading processing unit that performs cross-correlation calculation with a fully orthogonal coding pattern on the spread spectrum signal and searches for the peak value of the power and the position of the peak, a noise calculation unit that estimates noise power from the peak value, and a demapping unit that weights the result of the correlation calculation with the estimated noise power. This improves the error correction capability for spreading spectrum communication using orthogonal coding in which no known signals are inserted into the data frame, improves the reliability of communication, and enables high-speed communication.

[0018] Specifically, in a wireless communication device that receives a transmitted signal spread using Walsh coding, the characteristics of Walsh coding are utilized to calculate the received noise power using the received symbol itself, and this received noise power is used to weight the likelihood obtained by despreading, thereby improving the error correction capability. In other words, the noise power is calculated using the received symbol itself and used in LLR calculation.

[0019] Furthermore, this system can utilize multipath gain by weighting the received noise power, which takes RAKE synthesis into account, with the likelihood of the received symbol itself that has been RAKE synthesized. This improves the ability to track fluctuations in the propagation path, enhances error correction capabilities, improves the reliability of communication, and enables faster communication.

[0020] This system is based on the first embodiment (first system) described below, with the second embodiment (second system) serving as an application example.

[0021] [System 1: Figure 1] The first embodiment of this system (the first system) will be described with reference to Figure 1. Figure 1 is a block diagram of the configuration of the first system. As shown in Figure 1, the first system includes, as the transmitting side (transmitting device), an error correction coding unit 101, an interleaving unit 102, a spreading processing unit 103, and a mapping unit 104, and as the receiving side (receiving device), a despreading processing unit 105, a noise calculation unit 106, a demapping unit 107, a deinterleaving unit 108, and an error correction decoding unit 109. The following describes in detail the components of the transmitting and receiving devices of the first system.

[0022] [Transmitter of the first system] [Error correction coding unit 101] The error correction coding unit 101 performs error correction coding on the input transmission data, such as convolution coding or LDPC (Low-Density Parity-Check) coding, to form a transmission bit sequence, which is then output to the interleaving unit 102.

[0023] [Interleaving Section 102] The interleaving unit 102 swaps the transmission bit sequence in a predetermined order and outputs it to the spreading logic unit 103 in order to distribute errors in the transmission frame.

[0024] [Diffusion processing unit 103] The diffusion processing unit 103 performs diffusion processing using Walsh codes, which are fully orthogonal codes, and outputs the diffusion results to the mapping unit 104. Although the diffusion processing unit 103 uses Walsh codes, it is not limited to this code pattern as long as the codes are fully orthogonal.

[0025] [Example of Walsh coding: Figures 2, 3] Here, examples of Walsh codes are shown in Figures 2 and 3. Figure 2 shows an example of a 2-bit transmission Walsh code, and Figure 3 shows an example of a 4-bit transmission Walsh code. The Walsh code repeats this coding pattern depending on the diffusion number.

[0026] For example, in the case of 2-bit transmission with a spreading number of 32, the code pattern will be repeated 32 / 4 = 8 times. Furthermore, in the case of 4-bit transmission with a spreading number of 32, the code pattern is repeated 32 / 16 = 2 times. These code patterns are completely orthogonal to each other. Here, let K be the number of code patterns. In the example in Figure 2, K=4, and in the example in Figure 3, K=16.

[0027] For example, the code pattern for transmitting "01" using 2-bit transmission and a spreading number of 32 is given by equation 1.

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[0028] If the index of the transmitted symbol is m, and the index after spreading is n, then the transmitted sequence s(n) after spreading at the mth symbol is given by equation 2.

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[0029] [Mapping section 104] The mapping unit 104 performs symbol mapping based on the input diffusion result s(n). Symbol mapping, for example, maps a diffusion result of 0 to 1+j0 and a result of 1 to -1+j0, as shown in equation 3.

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[0030] [Receiver of the first system] [Reverse diffusion processing unit 105: Figure 4] The despreading processing unit 105 performs a correlation calculation with the received signal against all the code patterns shown in Equation 1, and outputs the correlation result to the noise calculation unit 106 and the demapping unit 107. The reverse diffusion processing unit 105 will be explained using Figure 4. Figure 4 is a block diagram of the configuration of the reverse diffusion processing unit of the first system. As shown in Figure 4, the inverse diffusion processing unit 105 includes a correlation calculation unit 201 and a peak detection unit 202.

[0031] [Correlation Calculation Unit 201] The correlation calculation unit 201 calculates the relationship between the received signal y(n) and the reference signal r i A correlation operation, i.e., de-diffusion, is performed. The correlated output C of code pattern i. i (n) is calculated by the following formula.

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[0032] Here, r i is the code pattern s shown in Equation 2 repeated according to the diffusion number, i which is mapped based on Equation 3. Here, l (ell) is the chip index of diffusion, and " * " represents the complex conjugate. Also, when the transmitted signal is x(n) and the noise is v(n), the received signal y(n) is given by Equation 5.

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[0033] [Peak Detection Unit 202: Figures 5, 6] The peak detection unit 202 searches for the maximum value P of all code indices where the power is maximum in an interval of length L v,max and its peak position P n , and determines the value P n of each code pattern i at the peak position P v,i (m). The maximum value is given by Equation 6, and the value P v,i (m) of each code pattern i at the peak position is given by Equation 7.

[0034]

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[0036] [Noise calculation unit 106] The noise calculation unit 106 calculates the peak value P of each Walsh code. v,i The noise power is estimated using equation 14 and output to the demapping unit 107. The correlation output other than the transmitted Walsh code is 0, as shown in Figure 5, in the absence of noise. Therefore, the correlation output other than the Walsh code can be considered to be noise components.

[0037] At the peak position in equation 4, x(nl) = r k (Ll-1), and y(nl) can be rewritten as shown in equation 9.

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[0038] Using the properties of equation 8, P v,i (m) is given by equation 11.

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[0039] From equation 11, P for i ≠ k v,i (m) shows that the encoded data portion is canceled out, and theoretically the noise component can be extracted. Here, r i *The magnitude of (l) is "1", and assuming that v(n) is white Gaussian noise, it has the same variance regardless of the value of n. If this variance is shown in [Equation 12], then P for i ≠ k v,i The expected value of (m) is given by formula 12 in [Equation 13].

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[0040] Here, L is the diffusion number, and Lσ is the right-hand side of equation 12. 2 v,i This represents the noise power of the received symbol. The total P of i≠k v,i The average noise power of (m) is given by equation 13 in [Equation 14].

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[0041] In other words, the noise power (the right-hand side of equation 14) is P v,i From the total sum of the power of (m), the maximum P v,i We only need to calculate the average after subtracting the power of (m), which can be calculated using formula 14 in [Equation 15].

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[0042] [Demapping section 107] The demapping unit 107 receives the total inverse diffusion value P calculated by the inverse diffusion processing unit 105. v,i (m) and the noise power calculated by formula 14 in the noise calculation unit 106 are used to calculate the bit LLR shown in [Formula 16] and output to the deinterleaving unit 108.

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[0043] In typical single-carrier or OFDM (Orthogonal Frequency-Division Multiplexing) synchronous detection communications, the likelihood is calculated using the distance between the ideal constellation and the receiving point. However, in despreading, the likelihood can be calculated using, for example, the maximum value of all code patterns shown in [Equation 17], or by sorting all code patterns shown in [Equation 17] in descending order and using the difference between the first and second most likely values.

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[0044] As an example, we will explain the method of using the maximum value as the likelihood. [Equation 17] shows the maximum value Φ(m) of the descension value for all sign patterns and the sign pattern index P of the maximum value. i Extract (m) using formula 15 in [Equation 18].

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[0045] The noise weighting is Φ(m) and P i Use (m) and calculate using formula 16 in [Equation 19].

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[0046] Here, bitget(a,b) represents the b-th bit when a is represented in binary, counting from the MSB. The right-hand side of equation 16 is "1-2·bitget(P i The calculation (m) and (b) manipulates the original sign pattern so that the bit in question takes a value of +1 (positive value) when it is 0, and a value of -1 (negative value) when it is 1.

[0047] [Deinterleaving Section 108] The deinterleaving unit 108 restores the LLR sequence, which corresponds to the transmission bit sequence rearranged in a predetermined order by the interleaving unit 102, to its original order and outputs it to the error correction decoding unit 109. [Error correction / decoding unit 109] This unit performs error correction decoding corresponding to the algorithm encoded by the error correction coding unit 101, such as Viterbi decoding or LDPC (Low Density Parity Check) decoding.

[0048] The first system described above calculates the received noise power from the received symbol itself, and by weighting the received noise power with the likelihood of the received symbol itself, it is possible to improve the ability to track fluctuations in the propagation path, thereby improving error correction capability, and achieving improved reliability and speed of communication.

[0049] [Second system: Figure 7] A second embodiment of this system (the second system) will be described with reference to Figure 7. Figure 7 is a block diagram of the configuration of the second system. As shown in Figure 7, the second system includes, on the transmitting side (transmitting device), an error correction coding unit 101, an interleaving unit 102, a spreading processing unit 103, and a mapping unit 104, and on the receiving side (receiving device), a despreading processing unit 301, a noise calculation unit 302, a demapping unit 107, a deinterleaving unit 108, and an error correction decoding unit 109.

[0050] The error correction coding unit 101, the interleaving unit 102, the diffusion processing unit 103, the mapping unit 104, the demapping unit 107, the deinterleaving unit 108, and the error correction decoding unit 109 are the same as those in the first system, so their explanation is omitted.

[0051] [Reverse diffusion processing unit 301: Figure 8] The despreading processing unit 301 performs a correlation calculation with the received signal against all code patterns and outputs the correlation result to the noise calculation unit 302 and the demapping unit 107. The despreading processing unit 301 will be explained with reference to Figure 8. Figure 8 is a block diagram of the configuration of the despreading processing unit of the second system. As shown in Figure 8, the inverse diffusion processing unit 301 comprises a correlation calculation unit 201, a peak detection unit 401, and a RAKE synthesis unit 402. Furthermore, since the correlation calculation unit 201 is identical to that of the first system, its explanation will be omitted.

[0052] [Peak detection unit 401] As shown in [Equation 20], the peak detection unit 401 determines the peak position P, which is the maximum value position of all code indices where the power is maximum in an interval of length L. n1 We search for this using equation 17, and the value P of each sign pattern at the peak position. v1,i The peak position P is determined by equation 18. n1 The peak position P is the maximum value of all sign indices where the power is highest in the same section excluding the peak P, i.e., the second peak. n2 We search for this using equation 19, and the value P of each sign pattern at the second peak position. v2,i This is determined by equation 20.

[0053]

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[0054] [RAKE synthesis unit 402: Figures 9 and 10] The RAKE synthesis unit 402 synthesizes the first peak component and the second peak component, which is a multipath component, and adds the multipath gain. Figure 9 shows an image of the values ​​shown in [Equation 21] when there is multipath. Figure 9 is an explanatory diagram showing an image of the correlated output when there is multipath.

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[0055] Next, the configuration of the RAKE synthesis unit 402 will be explained with reference to Figure 10. Figure 10 is a block diagram of the configuration of the RAKE synthesis unit of the second system. As shown in Figure 10, the RAKE synthesis unit 402 includes a phase correction coefficient calculation unit 501, a power difference determination unit 502, and a maximum ratio synthesis unit 503.

[0056] [Phase correction coefficient calculation unit 501] The phase correction coefficient calculation unit 501 calculates a phase correction coefficient to align the phases of the first peak and the second peak and outputs it to the maximum ratio combining unit 503 and the noise calculation unit 302. The phase correction coefficient is calculated, for example, by using the moving average of the M symbols before and after the symbol in question, as shown in equations 21 and 22 of [Equation 22].

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[0057] Here, w1(m) is the phase correction coefficient for the first peak, w2(m) is the phase correction coefficient for the second peak, and k p This is the sign index of the peak value. By multiplying by this phase correction coefficient, the phase is aligned with the real axis.

[0058] [Power difference determination unit 502] The power difference determination unit 502 outputs the determination signal A to the maximum ratio combining unit 503 and the noise calculation unit 302. The determination signal A is determined to be either "0" or "1" by formula 23 in [Equation 23].

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[0059] Here, γ is the judgment threshold. The intention of this judgment process is that if the difference between the first and second peaks is large, the second peak may be noise, and if the first peak is sufficiently large compared to the second peak, demodulation of only the first peak is acceptable. For example, γ is set to "0.25".

[0060] [Maximum ratio synthesis section 503] The maximum ratio combining unit 503 performs maximum ratio combining using the coefficient calculated by the phase correction coefficient calculation unit 501, selects an output signal based on the determination result of the power difference determination unit 502, and outputs it to the demapping unit 107. The maximum ratio combining is performed according to formula 24 in [Equation 24].

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[0061] [Noise calculation unit 302] The noise calculation unit 302 calculates the peak value P of each Walsh code. v1,i , P v2,i The combined noise power, taking RAKE synthesis into consideration, is estimated and output to the demapping unit 107. The noise calculation method is the same as that shown in the first system, and the noise power when RAKE synthesis is performed in the RAKE synthesis unit 402 is given by equation 26 in [Equation 26].

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[0062] The RAKE synthesis results are synthesized at the maximum ratio, therefore (|w1| 2 +|w2| 2 The noise is normalized by dividing by ). The noise power when RAKE synthesis is not performed in the RAKE synthesis unit 402 is given by equation 27 in [Equation 27].

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[0063] The power difference determination unit 502 selects the output as shown in equation 28 of [equation 28] based on the determination signal A.

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[0064] According to the second system described above, the received noise power of the leading and delayed waves of the received symbol itself is calculated, and the received noise power considering the RAKE synthesis is weighted against the likelihood of the received symbol itself after RAKE synthesis. This utilizes multipath gain and improves the ability to track fluctuations in the propagation path, thereby improving error correction capability, enhancing the reliability of communication, and enabling faster communication.

[0065] Furthermore, while the second system was explained by two RAKE synthesiss up to the second peak, the same applies to three or more RAKE synthesiss from the third peak onward, and the number of RAKE synthesiss is not limited to two; it can be three or more.

[0066] This system is specialized in modulation and demodulation processing. In addition to the functions described above, it also includes wireless communication equipment such as a frequency converter, power amplifier, transmitting and receiving antenna, low-noise amplifier, AFC processing unit, and synchronization acquisition unit, but these are common functions in this system and have therefore been omitted from the explanation.

[0067] [Effects of the embodiment] According to this system, the transmitting device is equipped with a spreading spectrum processing unit 103 that performs spreading spectrum using fully orthogonal coding on the signal to be transmitted, and the receiving device is equipped with a despreading processing unit 105 that performs cross-correlation calculations with fully orthogonal coding patterns on the spread spectrum signal and searches for the peak value of the power and the position of the peak, a noise calculation unit 106 that estimates noise power from the peak value, and a demapping unit 107 that weights the result of the correlation calculation with the estimated noise power. As a result, it is possible to improve error correction capability for spreading spectrum communication using orthogonal coding in which no known signals are inserted into the data frame, improve the reliability of communication, and achieve high-speed communication.

[0068] Furthermore, this system utilizes multipath gain by weighting the received noise power, which takes RAKE synthesis into account, with the likelihood of the received symbol itself after RAKE synthesis. This improves the ability to track fluctuations in the propagation path, enhances error correction capabilities, improves the reliability of communication, and enables faster communication. [Industrial applicability]

[0069] The present invention is suitable for wireless communication systems and methods that improve error correction capability for spread spectrum communication using orthogonal coding in which no known signals are inserted into the data frame, thereby improving the reliability of communication and increasing the speed of communication. [Explanation of Symbols]

[0070] 101…Error correction coding unit, 102…Interleaving unit, 103…Diffusion processing unit, 104…Mapping unit, 105…Despreading processing unit, 106…Noise calculation unit, 107…Demapping unit, 108…Deinterleaving unit, 109…Error correction decoding unit, 201…Correlation calculation unit, 202…Peak detection unit, 301…Despreading processing unit, 302…Noise calculation unit, 401…Peak detection unit, 402…RAKE synthesis unit, 501…Phase correction coefficient calculation unit, 502…Maximum ratio synthesis unit, 503…Power difference determination unit

Claims

1. A wireless communication system comprising a transmitting device and a receiving device, The transmitting device includes a spreading spectrum processing unit that performs spreading spectrum using fully orthogonal coding on the signal to be transmitted. The receiving device comprises a despreading processing unit that performs a cross-correlation calculation with a fully orthogonal coding pattern on the spread spectrum signal and searches for the peak value of the power and the position of the peak; a noise calculation unit that estimates noise power from the peak value; and a demapping unit that weights the result of the correlation calculation with the estimated noise power. The despreading processing unit includes a correlation calculation unit that performs a correlation calculation between the received signal and a reference signal of all code patterns for the received signal for each data symbol, and a peak detection unit that searches for the peak value where the power is maximum in a specific section and the position of the peak, and determines the value of each code pattern at the position of the peak as a despreading result. The noise calculation unit estimates the noise power for each data symbol, The wireless communication system is characterized in that the demapping unit calculates the bit log-likelihood ratio using the despreading result and the noise power for each data symbol.

2. The wireless communication system according to claim 1, characterized in that the despreading processing unit includes a RAKE combining unit that searches for the peak values ​​and peak locations for multiple power peaks and combines the values ​​of the searched multiple peaks.

3. A wireless communication method between a transmitting device and a receiving device, The transmitting device performs spread spectrum using fully orthogonal coding on the signal to be transmitted. The receiving device performs a cross-correlation calculation with a fully orthogonal coding pattern on the spread spectrum signal, searches for the peak value of the power and the position of the peak, estimates the noise power from the peak value, and weights the result of the correlation calculation with the estimated noise power, wherein the receiving device performs a correlation calculation between the received signal and a reference signal of all coding patterns for the received signal for each data symbol, searches for the peak value and the position of the peak where the power is maximum in a specific interval, determines the value of each coding pattern at the peak position as a despread result, estimates the noise power for each data symbol, and calculates the bit log-likelihood ratio using the despread result and the noise power for each data symbol.

4. The wireless communication method according to claim 3, characterized in that the receiving device searches for the peak value and peak location for multiple power peaks, and synthesizes the values ​​of the searched multiple peaks.

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