JP2017041799A - Peak suppression device, peak suppression program and transmission device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress PAPR while suppressing EVM deterioration by a small-scale and low-delay circuit.SOLUTION: A peak suppression device comprises: coordinate transformation means for obtaining based on an inputted complex digital signal a first phase in the case where the complex digital signal is represented as two complex digital signals having an equal amplitude by shifting a second phase in positive and negative directions with a first phase that is a phase of a polar coordinate, defined as a center, and a signal component including amplitude information of the inputted complex digital signal; conversion means for quantizing a value of the signal component using a preset control table; and inverse coordinate transformation means for restoring the complex digital signal based on the first phase and the quantized signal component.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a peak suppressor, a peak suppression program, and a transmitter, and, for example, in an Orthogonal Frequency Division Multiplexing (OFDM) system, a peak-to-average power ratio (PAPR) of a transmission signal. The present invention can be applied to a transmission device that reduces noise.

  For example, the OFDM method is adopted as a modulation method such as LTE (Long Term Evolution). In the OFDM scheme, transmission is performed using a large number of subcarriers modulated with different data. Therefore, as the number of subcarriers increases, the ratio (PAPR) of the peak power value to the average power value of the transmission signal increases.

  The power amplifier in the transmission apparatus has a saturation characteristic for improving power efficiency. Therefore, the signal peak of the OFDM signal is clipped by the power amplifier or a large distortion occurs. This can be solved by ignoring the power efficiency of the power amplifier and using only a linear region, but it is not suitable for high-power transmission.

  In addition, nonlinear distortion occurs when affected by the nonlinear characteristics of the power amplifier. Therefore, transmission characteristics are deteriorated, and out-of-band radiation can occur. In other words, the non-linear distortion increases the signal level outside the band, which greatly affects adjacent systems using adjacent bands. Therefore, it is necessary to reduce PAPR.

  Conventionally, as described in Non-Patent Documents 1 to 4, PAPR suppression methods satisfying the requirement that no change is made in the process of generating an OFDM symbol of a signal to be transmitted and no change is made by additional signal processing on the receiving side. A proposed method has been proposed.

  Non-Patent Documents 1 and 2 propose a method called Peak Windowing. The Peak Windowing method is a method of cutting edge portions by convolving a window function (for example, Hanning, Kaiser, Hamming, etc.) with respect to a peak suppression signal to obtain a smooth waveform. This scheme designs the window function to have a spectrum only within the signal band. According to this method, an out-of-band leakage power ratio (ACLR: Adjacent Channel Leakage Ratio) can be suppressed. On the other hand, since the in-band distortion electric energy (EVM) is degraded, there is a trade-off relationship.

  Non-Patent Document 3 proposes a method called a Clipping & Filtering method. The Clipping & Filtering method is a method in which a portion exceeding a signal threshold is cut by clipping, and an ACLR generated by the cut is removed by a filter. Non-Patent Document 3 shows various characteristics when this Clipping & Filtering is performed only once.

  Non-Patent Document 4 proposes a method called a Peak Cancellation method. The Peak Cancellation method does not cancel all the signals exceeding the threshold at a time, but extracts several peak points from the signal time series, etc., generates a peak suppression signal for this, and applies it to perform PAPR suppression This method repeats the process. There are various methods for finding peaks and the number of detected peaks to be processed. Non-Patent Document 4 proposes a method of performing PAPR suppression processing while checking ACLR and EVM.

JOUKO VANKA, Digital Synthesizers and Transmitters for Software Radio, Springer, Chap. 17, 2005. R. van Nee, and A. de Wild, “Reducing the Peak-to-Average Power Ratio of OFDM,” IEEE Vehicular Technology Conference, Vol. 3, pp. 2072-2076, 1998. X. Li and L. J. Cimini, Jr., “Effects of clipping and filtering on the performance of OFDM,” IEEE Comm. Letter, Vol. 5, pp. 131-133, 1998. Takaya Hino, Osamu Hamada, Hiroshi Furukawa, “Study on peak amplitude suppression of OFDM signal under out-of-band leakage power constraint,” IEICE Transactions B Vol. J97-B No. 6 pp. 454-464, 2014.

  However, all of the above-described conventional techniques have a large load related to PAPR suppression processing and require a large-scale circuit configuration. Therefore, in order to reduce the processing load related to PAPR suppression processing, the circuit scale can be reduced. It is strongly desired. In addition, with the recent increase in functionality of mobile communication technology, the amount of signal processing in the base station has increased, and therefore reduction of processing delay is also strongly desired.

  Therefore, in view of the above problems, the present invention proposes a coordinate conversion process of complex signals (complex digital signals) and a PAPR suppression method using a control table, and reduces EVM degradation with a small-scale and low-delay circuit. It is an object of the present invention to provide a peak suppression device, a peak suppression program, and a transmission device that can suppress PAPR while suppressing it.

  In order to solve this problem, a peak suppressor according to a first aspect of the present invention is a peak suppressor that suppresses a peak power value of a transmitted signal. (1) Based on an input complex digital signal, The first phase when the digital signal is expressed as two complex digital signals with equal amplitudes, the first phase being a phase in polar coordinates and the second phase shifted in positive and negative directions as a center, and an input Coordinate conversion means for obtaining a signal component including amplitude information of the complex digital signal, (2) signal component conversion means for quantizing the value of the signal component using a preset control table, and (3) first Inverse coordinate transformation means for restoring the complex digital signal based on the phase of 1 and the quantized signal component is provided.

  A peak suppression program according to a second aspect of the present invention is a peak suppression program for suppressing a peak power value of a transmitted signal. (1) Based on an input complex digital signal, a complex digital signal is converted into polar coordinates. The first phase when expressed as two complex digital signals of equal amplitude with the second phase shifted positively or negatively with the first phase as the center at the center, and the amplitude of the input complex digital signal A coordinate conversion means for obtaining a signal component including information, (2) a signal component conversion means for quantizing a value of the signal component using a preset control table, and (3) a first phase; Based on the quantized signal component, it functions as an inverse coordinate transformation means for restoring a complex digital signal.

  A transmission apparatus according to a third aspect of the present invention is a transmission apparatus that performs a modulation process on transmission data and transmits a signal obtained by converting a modulated complex digital signal into a carrier frequency and amplifying the power. And a peak suppressor according to the above.

  According to the present invention, a coordinate conversion process for complex signals and a PAPR suppression method using a control table are proposed, and PAPR can be suppressed while suppressing EVM degradation with a small-scale and low delay circuit.

It is a block diagram which shows the internal structure of the radio | wireless transmitter which concerns on 1st Embodiment. It is a block diagram which shows the internal structure of the PAPR suppression process part 12 which concerns on 1st Embodiment. It is a functional block diagram which shows the detailed function of the PAPR suppression process part 12 which concerns on 1st Embodiment. It is a figure which shows complementary cumulative probability distribution when performing the PAPR suppression with respect to the input complex digital signal which concerns on 1st Embodiment. It is explanatory drawing which shows the relationship between the number of quantization bits of 2nd phase (phi) 'converted using the (phi) control table 231 which concerns on 1st Embodiment, and PAPR and EVM. It is a figure which shows an example of (phi) control table 231 of 1st Embodiment. It is explanatory drawing explaining the PAPR suppression process which concerns on 1st Embodiment. It is a functional block diagram which shows the detailed function of the PAPR suppression process part 12 which concerns on 2nd Embodiment.

(A) First Embodiment Hereinafter, a first embodiment of a peak suppression device, a peak suppression program, and a transmission device according to the present invention will be described in detail with reference to the drawings.

(A-1) Configuration of First Embodiment FIG. 1 is a block diagram illustrating an internal configuration of a wireless transmission device according to the first embodiment.

  The hardware configuration of the wireless transmission device 1 according to the first embodiment includes, for example, an electronic circuit such as a CPU, ROM, RAM, EEPROM, input / output interface unit, and communication device. Further, various functions of the wireless transmission device 1 may be realized by the CPU executing a processing program (software) stored in the ROM. The processing program (software) may be constructed by being installed in the ROM. Even in this case, the various functions of the wireless transmission device 1 can be represented by the blocks shown in FIG.

  In FIG. 1, the wireless transmission device 1 according to the first embodiment includes a baseband unit 11, a PAPR suppression processing unit 12, a digital-analog converter (DAC) 13, an RF processing unit 14, a power amplifier 15, and an antenna unit 16. Have.

  The baseband unit 11 outputs a complex signal (complex digital signal) obtained by orthogonal modulation to transmission data input as a baseband signal to the PAPR suppression processing unit 12.

  The PAPR suppression processing unit 12 receives a complex digital signal that is subject to PAPR suppression from the baseband unit 11, separates it into two complex digital signals of equal amplitude, and converts them into two phase components by coordinate conversion. Then, the PAPR suppression processing unit 12 converts one phase component of the two phase components using a preset control table. The PAPR suppression processing unit 12 generates a complex digital signal after PAPR suppression by inverse coordinate conversion, using the phase component after conversion obtained by converting the phase information using the control table. The detailed configuration and processing of the PAPR suppression processing unit 12 will be described later.

  The digital-analog converter (DAC) 13 converts the complex digital signal after PAPR suppression into an analog signal by the PAPR suppression processing unit 12 and supplies the analog signal to the RF processing unit 14.

  The RF processing unit 14 converts the output signal converted by the DAC 13 into signals in the frequency bands of a plurality of subcarriers and supplies the signal to the power amplifier 15.

  The power amplifier 15 outputs a signal obtained by adding a gain to the power value of the signal output from the RF processing unit 14.

  The antenna unit 16 transmits the signal output from the power amplifier 15 as a radio wave.

  FIG. 2 is a block diagram showing an internal configuration of the PAPR suppression processing unit 12 according to the first embodiment. FIG. 3 is a functional block diagram showing detailed functions of the PAPR suppression processing unit 12 according to the first embodiment.

  The PAPR suppression processing unit 12 can be configured by hardware, or can be realized by a CPU and software executed by the CPU (peak suppression program), but any implementation method is adopted. Even in this case, it can be functionally represented in FIGS.

  In FIG. 2, the PAPR suppression processing unit 12 according to the first embodiment includes a complex signal input unit 21, a coordinate conversion unit 22, a phase information conversion unit 23, an inverse coordinate conversion unit 24, and a complex signal output unit 25.

  The complex signal input unit 21 inputs a complex digital signal to be subject to PAPR suppression and supplies it to the coordinate conversion unit 22.

  The coordinate conversion unit 22 separates the complex digital signal given from the complex signal input unit 21 into two complex digital signals of equal amplitude and converts them into two phase components representing the characteristics of the complex signal.

Specifically, as shown in the equation (1), the coordinate conversion unit 22 converts the input complex digital signal x into a polar coordinate phase of the complex digital signal (hereinafter also referred to as a first phase). This is expressed as the sum of two complex digital signals of equal amplitude shifted in phase by the same phase (hereinafter also referred to as a second phase) φ with the positive and negative centered on θ. Here, y represents an arbitrary constant. Then, the coordinate conversion unit 22 converts the input complex digital signal x into the first phase θ and the second phase φ.
x = y · exp (j (θ + φ)) + y · exp (j (θ−φ)) (1)

More specifically, in FIG. 3, the | x | conversion unit 221 of the coordinate conversion unit 22 calculates the absolute value | x | of the input complex digital signal x, and the first phase conversion unit 222 ( 3) The second phase φ is derived using the complex digital signal x according to the equation (3). Further, the second phase conversion unit 223 of the coordinate conversion unit 22 derives the first phase θ using the input complex digital signal x according to the equation (2).
θ = tan ⁻¹ (x) (2)
φ = cos ⁻¹ (| x | / 2y) (3)

  In this way, the coordinate conversion unit 22 obtains, for example, the calculation of the expressions (2) and (3) without replacing the input complex digital signal x with the expression of the expression (1). The first phase θ and the second phase φ are obtained. Both the first phase θ and the second phase φ are values in the range of 0 to 2π (or −π to π).

  Further, the coordinate conversion unit 22 gives the converted first phase θ to the inverse coordinate conversion unit 24 and gives the second phase φ to the phase information conversion unit 23.

  The phase information conversion unit 23 uses the one or more φ control tables 231 set in advance so that the PAPR of the signal after PAPR suppression becomes a desired PAPR for the second phase φ given from the coordinate conversion unit 22. Is used to convert the phase information of the second phase φ. The second phase converted by the phase information conversion unit 23 using the φ control table is expressed as φ ′.

  Here, the first phase θ as the phase component converted by the coordinate conversion unit 22 includes only the phase information of the input complex digital signal x. On the other hand, the amplitude information of the input complex digital signal x is included only in the second phase φ. Therefore, the PAPR of the output signal can be suppressed by converting the distribution of the second phase φ including the amplitude information of the input complex digital signal x into a distribution of a signal having a desired PAPR. it can.

  Further, the phase information conversion unit 23 performs the conversion of the distribution of the second phase φ by using one or a plurality of φ control tables 231 set in advance. The phase information conversion unit 23 refers to the φ control table 231 and converts the second phase φ, so that it is not necessary to perform an operation with a high processing load, and the circuit scale can be reduced.

  Here, the φ control table 231 can be created from the value of the second phase φ using a quantization technique based on the signal suppressed to a desired PAPR. The first embodiment exemplifies a case where the φ control table 231 is created using the Lloyd-MAX method that is a nonlinear quantization method. Of course, the method applied to the quantization method is not limited to the Lloyd-MAX method.

  The inverse coordinate conversion unit 24 uses the second phase φ ′ converted by the phase conversion unit 23 and the first phase θ obtained by the coordinate conversion unit 22 to restore a complex digital signal by inverse coordinate conversion. Then, the signal is given to the complex signal output unit 25. That is, as shown in FIG. 3, the complex signal restoration unit 241 restores the complex digital signal by substituting the first phase θ and the second phase φ ′ having two equal amplitudes into the equation (1). .

  The complex signal output unit 25 outputs the complex digital signal given from the inverse coordinate conversion unit 24 to the DAC 13 at the subsequent stage.

  FIG. 4 is a diagram illustrating a complementary cumulative distribution function (CCDF) when PAPR suppression is performed on an input complex digital signal according to the first embodiment. In the case of the example in FIG. 4, the number of quantization bits of the second phase φ ′ converted by the phase information conversion unit 23 using the φ control table 231 is 7 bits.

In FIG. 4, the solid line indicates the peak characteristics of the input complex digital signal that has not been subjected to PAPR suppression processing. In this case, the peak power value (PAPR) corresponding to CCDF of 10 ⁻⁵ is 11.1 dB.

  On the other hand, in FIG. 4, the dotted line is the peak characteristic when the target PAPR is 8 dB, the broken line is the peak characteristic when the target PAPR is 7 dB, and the one-dot broken line is the target PAPR of 6 dB. It is a peak characteristic when

As illustrated in FIG. 4, the phase information conversion unit 23 converts the second phase φ into the second phase φ ′ using the φ control table 231 and reflects the converted second phase φ ′. It can be seen that the processed complex digital signal can be suppressed to a desired target PAPR. That is, for example, when target PAPR = 8 dB, the peak power value (PAPR) corresponding to CCDF of 10 ⁻⁵ is suppressed to 8 dB. Compared to the case where PAPR suppression processing is not performed, PAPR is It can be seen that it has been suppressed. Similarly, when the target PAPR = 7 dB or the target PAPR = 6 dB, the peak power value (PAPR) corresponding to the CCDF of 10 ⁻⁵ is 7 dB or 6 dB, and the PAPR can be suppressed. I understand that.

  FIG. 5 is an explanatory diagram illustrating a relationship between the number of quantization bits of the second phase φ ′ converted using the φ control table 231 according to the first embodiment, and PAPR and EVM. FIG. 5 shows the relationship between PAPR and EVM when the target PAPR is 8 dB, 7 dB, and 6 dB, and the number of quantization bits of the second phase φ ′ is any one of 2 to 7 bits.

  As shown in FIG. 5, it can be seen that the EVM tends to be lowered as the number of quantization bits of the second phase φ ′ increases. Further, if the number of quantization bits of the second phase φ ′ is 5 bits or more, it can be suppressed to a desired PAPR (ie, target PAPR). For example, when the number of quantization bits is 5 and the target PAPR is 8 dB, 7 dB, and 6 dB, the respective EVMs are 1.7%, 2.3%, and 3.7%.

  For example, when compared with EVM = 17.5%, 12.5%, and 8%, which are required qualities of QPSK, 16QAM, and 64QAM in LTE communication defined by 3GPP, after PAPR suppression according to the first embodiment Even if the target PAPR is 6 dB, the EVM is less than 4%, and therefore satisfies the requirements specified in 3GPP and can be said to be a highly practical process.

  Conventional PAPR suppression control of a complex digital signal needs to control two variables of a real part and an imaginary part of the complex digital signal. On the other hand, in the first embodiment, PAPR can be suppressed by controlling only the second phase (phase component) including the amplitude component of the complex digital signal.

  Specifically, for example, when the number of bits of the input complex digital signal is 15 bits, the conventional PAPR suppression control is also performed with 15 bits. On the other hand, according to the first embodiment, for example, by using the φ control table 231 having a quantization bit number of 5 bits, the PAPR suppression process is performed with 5 bits, so that the processing load can be reduced. Therefore, the circuit scale can be reduced.

  In addition, since the conventional PAPR suppression control uses a filter process or the like, a processing delay occurs. In contrast, in the first embodiment, processing can be performed by referring to the φ control table, so that processing delay can be suppressed.

  FIG. 6 is a diagram illustrating an example of the φ control table 231 according to the first embodiment.

  FIG. 6 illustrates the case where the number of quantization bits of the second phase φ ′ is 3 bits and 5 bits, but the number of quantization bits of the second phase φ ′ is limited to this. is not. The number of quantization bits of the second phase φ ′ is preferably 5 bits or more.

  In FIG. 6, the φ control table 231 is generated by the nonlinear quantization method in which the quantization level is changed according to the value of the second phase φ as described above. In addition, the φ control table 231 is generated in advance according to the PAPR characteristic and EVM characteristic of the signal after PAPR suppression as described above.

  In addition, in order to flexibly correspond to the system to which the wireless transmission device 1 is applied and the actual performance of the power amplifier 15 to be mounted, a plurality of φ control tables 231 are set in advance. The φ control table 231 may be used.

(A-2) Operation of the First Embodiment Next, PAPR suppression processing in the wireless transmission device 1 according to the first embodiment will be described in detail with reference to the drawings.

  FIG. 7 is an explanatory diagram illustrating the PARP suppression process according to the first embodiment.

  The input transmission data is subjected to digital quadrature modulation to a desired carrier frequency by the baseband unit 11, and a complex digital signal obtained by the quadrature modulation is supplied to the PAPR suppression processing unit 12.

  7, in the PAPR suppression processing unit 12, a complex digital signal x is given to the complex signal input unit 21, and a complex digital signal x as a control target signal is given to the coordinate conversion unit 22 (see FIG. 7A). ).

  In the coordinate conversion unit 22, the first phase θ is derived using the complex digital signal x according to the equation (2), and the first phase θ is given to the inverse coordinate conversion unit 24. Further, the coordinate conversion unit 22 derives the second phase φ using the complex digital signal x according to the equation (3), and the second phase φ is given to the phase information conversion unit 23.

  For example, the second phase φ transformed by the coordinate transformation unit 22 has the distribution characteristics shown in FIG. The phase information conversion unit 23 refers to the φ control table 231 illustrated in FIG. 7C and applies nonlinear quantization to convert the second phase φ into the second phase φ ′.

  The second phase φ ′ converted by the phase information conversion unit 23 is given to the inverse coordinate conversion unit 24.

  In the inverse coordinate conversion unit 24, the complex digital signal is converted by inverse coordinate conversion using the second phase φ ′ given from the phase information conversion unit 23 and the first phase θ given from the coordinate conversion unit 22. It is restored and applied to the complex signal output unit 25.

  The complex digital signal subjected to PAPR suppression by the PAPR suppression processing unit 12 is converted into an analog signal by the DAC 13 and provided to the RF processing unit 14. The RF processing unit 14 converts the output signal converted by the DAC 13 into a frequency band signal. The power amplifier 15 outputs a signal obtained by adding a gain to the power value of the signal output from the RF processing unit 14, and the antenna unit 16 transmits a radio wave.

(A-3) Effects of the First Embodiment As described above, according to the first embodiment, since the PAPR suppression is performed using the coordinate conversion processing of the complex digital signal and the control table, the scale is small. With a low delay circuit, PAPR can be suppressed while suppressing EVM degradation.

(B) Second Embodiment Next, a second embodiment of the peak suppression device, the peak suppression program, and the transmission device according to the present invention will be described in detail with reference to the drawings.

  The configuration of the wireless transmission device according to the second embodiment is the same as or corresponds to the configuration shown in FIG. 2 of the first embodiment. Therefore, the second embodiment will be described with reference to FIG.

  In the second embodiment, the configuration and processing of the PAPR suppression processing unit are different from those in the first embodiment. Therefore, hereinafter, the configuration and processing of the PAPR suppression processing unit different from the first embodiment will be mainly described.

  FIG. 8 is a functional block diagram showing detailed functions of the PAPR suppression processing unit 12 according to the second embodiment.

  In FIG. 8, the PAPR suppression processing unit 12 according to the second embodiment includes a coordinate conversion unit 32, a phase information conversion unit 33, and an inverse coordinate conversion unit 34.

  The coordinate conversion unit 33 includes a | x | conversion unit 321 and a first phase conversion unit 322.

  The | x | conversion unit 321 derives the absolute value | x | of the input complex digital signal and supplies the derived | x | to the phase information conversion unit 33.

  The first phase conversion unit 322 derives the first phase θ using the complex digital signal x according to the equation (3), and gives the derived first phase θ to the inverse coordinate conversion unit 34.

  The phase information conversion unit 33 sets one or more of | x | given from the | x | conversion unit 321 of the coordinate conversion unit 32 so that the PAPR of the signal after PAPR suppression becomes a desired PAPR. Is converted into the second phase φ ′ using the | x | & φ control table 331.

  In the first embodiment described above, the case where the second phase φ including the amplitude information is converted into the second phase φ ′ with reference to the φ control table 231 is exemplified. On the other hand, in the second embodiment, the variable | x | including the amplitude information is converted into the second phase φ ′ by referring to the | x | & φ control table 331.

  The variable | x | of the complex digital signal x in the process of deriving the second phase φ also includes amplitude information of the complex digital signal x. Therefore, in the second embodiment, the phase information conversion unit 33 refers to the | x | & φ control table 331 and changes the variable | x | in the derivation process of the second phase φ to the second phase φ ′. Convert.

  The | x | & φ control table 331 can be created from the value of the second phase φ using a quantization technique based on the signal suppressed to a desired PAPR, as in the first embodiment. Also, the | x | & φ control table 331 is generated in accordance with the PAPR characteristic and EVM characteristic of the output signal after PAPR suppression.

  The inverse coordinate conversion unit 34 uses the second phase φ ′ converted by the phase information conversion unit 33 and the first phase θ obtained by the coordinate conversion unit 32 to convert the complex digital signal by inverse coordinate conversion. The data is restored and given to the complex signal output unit 25. That is, the complex signal restoration unit 341 restores the complex digital signal by substituting the first phase θ and the second phase φ ′ having two equal amplitudes into the equation (1).

  According to the second embodiment, in addition to the effects described in the first embodiment, the variable | x obtained in the process of deriving the second phase φ with reference to the | x | & φ control table 331 Since | is converted into the second phase φ ′, the processing load can be further reduced as compared with the first embodiment.

  DESCRIPTION OF SYMBOLS 1 ... Wireless transmitter, 11 ... Baseband unit, 12 ... PAPR suppression process part, 13 ... DAC, 14 ... RF process part, 15 ... Power amplifier, 16 ... Antenna part, 21 ... Complex signal input part, 22 and 32 ... Coordinate conversion unit, 23 and 33 ... phase information conversion unit, 24 and 34 ... inverse coordinate conversion unit, 25 ... complex signal output unit, 221 and 321 ... | x | conversion unit, 222 ... second phase conversion unit, 223 and 322 ... 1st phase conversion part, 231 ... (phi) control table, 331 ... | x | & phi control table, 241 and 341 ... complex signal decompression | restoration part.

Claims (7)

In the peak suppressor that suppresses the peak power value of the transmitted signal,
Based on the input complex digital signal, the complex digital signal is expressed as two complex digital signals having equal amplitudes in which the second phase is shifted positively and negatively around the first phase which is a phase in polar coordinates. Coordinate conversion means for obtaining the first phase in the case and a signal component including amplitude information of the input complex digital signal;
Signal component conversion means for quantizing the value of the signal component using a preset control table;
A peak suppressor comprising: an inverse coordinate transformation unit that restores a complex digital signal based on the first phase and the quantized signal component.   2. The peak suppressor according to claim 1, wherein the control table is generated by a quantization method according to a peak-to-average power ratio of a signal to be transmitted. The coordinate conversion means obtains the second phase including the amplitude component as the signal component,
The peak suppressor according to claim 1 or 2, wherein the signal component conversion means quantizes the second phase using the control table. The coordinate conversion means obtains the absolute value of the input complex digital signal,
The peak suppressor according to claim 1 or 2, wherein the signal component conversion means quantizes the absolute value of the complex digital signal using the control table.   The peak suppressor according to any one of claims 1 to 4, wherein the signal component conversion means has a plurality of the control tables in advance, and switches and uses the control tables to be applied. In the peak suppression program that suppresses the peak power value of the transmitted signal,
Computer
Based on the input complex digital signal, the complex digital signal is expressed as two complex digital signals having equal amplitudes in which the second phase is shifted positively and negatively around the first phase which is a phase in polar coordinates. Coordinate conversion means for obtaining the first phase in the case and a signal component including amplitude information of the input complex digital signal;
Signal component conversion means for quantizing the value of the signal component using a preset control table;
A peak suppression program that functions as an inverse coordinate transformation unit that restores a complex digital signal based on the first phase and the quantized signal component. In a transmission device that performs modulation processing on transmission data and transmits a signal obtained by converting the modulated complex digital signal to a carrier frequency and amplifying the power,
A transmission apparatus comprising the peak suppressor according to claim 1.

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