JP5244698B2 - Transmission power control apparatus and transmission power control method - Google Patents

Description

  The present invention relates to a transmission power control apparatus and a transmission power control method. More specifically, the present invention relates to transmission power control in a wireless transmitter that modulates and transmits two signals orthogonal to each other.

  In a wireless transmitter that performs digital modulation such as PSK (Phase Shift Keying) and ASK (Amplitude Shift Keying), it is possible to control transmission power in order to obtain stable transmission power. Has been done. In particular, the characteristics of semiconductors constituting an amplifier circuit and the like are likely to vary depending on the temperature. Therefore, it is necessary to stably control the transmission power even when the variation occurs. Several proposals have been made for controlling the transmission power of such a wireless transmitter.

  For example, in Patent Document 1, an in-phase component (I) and a quadrature component (Q) of a baseband signal are combined and modulated by a modulator, amplified by a variable gain amplifier, and then transmitted power signal amplified by a power amplifier. When outputting, a part of the transmission power signal is extracted by the coupler to detect the envelope component of the transmission power signal, and the envelope component is compared with the reference voltage generated by the reference voltage generation circuit. The error signal is fed back to the variable gain amplifier (see FIGS. 2 to 4 of Patent Document 1).

  In Patent Document 2, a baseband signal is separated into an in-phase component (I) and a quadrature component (Q) by a serial / parallel converter, modulated by a quadrature modulator, and amplified by a variable gain amplifier. The transmission power signal amplified by the power amplifier is output. In this case, the envelope detection circuit detects the envelope of the transmission power signal, the envelope signal of the in-phase component (I) and the quadrature component (Q) obtained from the serial / parallel converter, and the envelope detection by the correction circuit. An error signal with the envelope signal of the transmission power signal in which the nonlinearity of the circuit is corrected is fed back to the variable gain amplifier (see FIGS. 1 and 8 of Patent Document 2).

  In Patent Document 3, a power amplifier using a modulated wave as an input signal, a DC voltage conversion circuit for supplying a DC bias to the power amplifier, and an output voltage of the DC voltage conversion circuit as an envelope signal level of the modulation wave A directional coupler and an envelope detection circuit for further control, and a difference signal generation circuit for controlling the input signal of the power amplifier by the difference between the envelope signal level of the power amplifier and the envelope signal level of the output signal of the power amplifier (Refer to Fig. 1 etc. of Patent Document 3)

Japanese Patent Laid-Open No. 2003-124821 JP 09-23125 A Japanese Patent No. 2689011

  However, in Patent Documents 1 to 3, since an envelope of a transmission power signal is detected and the envelope signal is fed back to a variable gain amplifier circuit or the like to perform power control, a symbol that is a unit of modulation / demodulation When the frequency is low, there is a problem that transmission power follows the symbol frequency, that is, power control depends on transmission data. For this reason, it is necessary to reinforce the filter processing to absorb fluctuations in transmission power, and as the scale of the filter circuit increases and the filter calculation processing increases, it takes time to stabilize the transmission power. It was an obstacle to product miniaturization and price reduction.

  The present invention solves the above-described problem, enables power control independent of transmission data, and uses a small filter circuit with a simple filter calculation process to reduce the time until transmission power is stabilized. An object of the present invention is to provide a transmission power control apparatus and a transmission power control method that can reduce the size and price of a product.

In order to achieve the above object, a transmission power control apparatus according to the first aspect of the present invention inserts pseudo signals into mutually orthogonal I and Q signals representing symbols of information to be transmitted by signal strength and phase vectors. Sampling means for performing upsampling processing, modulation means for generating a modulation signal based on the I signal and Q signal upsampled by the sampling means, and amplifying the power of the modulation signal generated by the modulation means Power amplifying means for generating an output signal, and a transmission power control device comprising:
Detecting means for detecting an output signal generated by the power amplifying means to generate a feedback signal; and a feedback I signal having the same phase as the feedback signal by demodulating the feedback signal generated by the detecting means and the feedback Demodulation means for generating a feedback Q signal whose phase is orthogonal to the signal, and first extraction means for extracting an I signal and a Q signal in the vicinity of a symbol from the I signal and the Q signal upsampled by the sampling means, Second extraction means for extracting a feedback I signal and feedback Q signal in the vicinity of a symbol from feedback I signals and feedback Q signals obtained based on demodulation of the demodulation means, and extracted by the first extraction means The power amplification means according to the intensity difference between the signal intensity of the I signal and the Q signal and the signal intensity of the feedback I signal and the feedback Q signal extracted by the second extraction means. Thus a control means for controlling the power of the output signal generated,
It is characterized by providing.

  For example, the control means calculates the arithmetic mean of the square values of the amplitudes of the I and Q signals extracted by the first extracting means and calculates the scalar signal strength of the I and Q signals. The arithmetic means of the squares of the amplitudes of the feedback I signal and the feedback Q signal extracted by the first extraction means and the second extraction means is calculated, and the scalars of the feedback I signal and the feedback Q signal are calculated. And a second calculation means for calculating the signal intensity.

  For example, the transmission power control apparatus delays the time axis of the I signal and the Q signal extracted by the first extraction unit and delays the time of the feedback I signal and the feedback Q signal extracted by the second extraction unit. A delay means for matching the axis may be provided.

  For example, the transmission power control apparatus includes a filter unit that band-limits the I signal and the Q signal up-sampled by the sampling unit, and the first extraction unit includes the I signal and Q band-limited by the filter unit. The signal is down-sampled to extract the I signal and Q signal in the vicinity of the symbol, and the second extraction means performs the down-sampling process on the feedback I signal and feedback Q signal obtained based on the demodulation. The feedback I signal and feedback Q signal near the symbol may be extracted.

To achieve the above object, a transmission power control method according to the second aspect of the present invention inserts pseudo signals into mutually orthogonal I and Q signals representing symbols of information to be transmitted by signal strength and phase vectors. A transmission power control method that performs upsampling processing, generates a modulation signal based on the upsampled I signal and Q signal, amplifies the power of the generated modulation signal, and generates an output signal,
Detecting the generated output signal to generate a feedback signal; demodulating the generated feedback signal to generate a feedback I signal having the same phase as the feedback signal and a feedback Q signal having a phase orthogonal to the feedback signal; The I signal and Q signal near the symbol are extracted from the up-sampled I signal and Q signal, and the feedback I signal and feedback near the symbol are obtained from the feedback I signal and feedback Q signal obtained based on the demodulation. Extracting the Q signal, and controlling the power of the output signal according to the intensity difference between the signal intensity of the I signal and Q signal near the symbol and the signal intensity of the feedback I signal and feedback Q signal near the symbol; Features.

  For example, the arithmetic mean of the square value of the amplitude of each of the I signal and Q signal near the symbol is calculated to calculate the scalar signal strength of the I signal and Q signal, and the feedback I signal and feedback near the symbol The arithmetic mean of the square value of each amplitude of the Q signal may be calculated to calculate the scalar signal strength of the feedback I signal and the feedback Q signal.

  For example, the time axis of the I signal and Q signal near the symbol may be delayed so as to coincide with the time axis of the feedback I signal and feedback Q signal near the symbol.

  For example, band-limiting the up-sampled I signal and Q signal by filter processing, down-sampling processing is performed on the band-limited I signal and Q signal, and I and Q signals in the vicinity of the symbol are extracted. The feedback I signal and feedback Q signal obtained based on the demodulation may be down-sampled to extract the feedback I signal and feedback Q signal in the vicinity of the symbol.

  According to the present invention, by performing power control without being based on the envelope of the transmission power signal, it is possible to perform power control that does not depend on transmission data, and by using a small-scale filter circuit with simple filter operation processing, It is possible to shorten the time until the transmission power is stabilized, and to realize a reduction in size and price of the product.

It is a block diagram of the π / 4 shift QPSK transmitter in the embodiment of the present invention. It is a general figure which shows the constellation showing the vector signal with an intensity | strength and a phase. It is a figure which shows the signal after up-sampling by the up-sampling circuit of FIG. It is a figure which shows the constellation after an upsampling by the upsampling circuit of FIG. It is a figure which shows the signal by which the band limitation was carried out by the RRC filter circuit of FIG. It is a figure which shows the constellation of the signal by which the band limitation was carried out by the RRC filter circuit of FIG. It is a figure which shows the constellation of the signal downsampled by the downsampling circuit of FIG.

  Embodiments of a transmission power control apparatus and a transmission power control method according to the present invention will be described below with reference to the drawings, taking a π / 4 shift QPSK transmitter as an example.

  FIG. 1 is a block diagram of a 260 MHz band π / 4 shift QPSK transmitter according to an embodiment. In this transmitter, symbol data as information to be transmitted is orthogonal to each other, decomposed into vector signals having “strength” and “phase”, respectively, and transmitted after π / 4 shift QPSK modulation. That is, the signal strength is represented by a vector scalar, and the phase is represented by a vector angle.

  FIG. 2 is a general diagram showing a vector signal having intensity and phase by polar coordinates of the I axis and the Q axis, and is called “constellation”. For example, any two vector signals are represented by a black arrow and a white arrow in FIG. As described above, when transmission power is controlled based on vector signals having greatly different intensities (scalars), stable transmission power cannot be obtained. In the present embodiment, the transmission power is controlled by the configuration of FIG. 1 so as not to be affected by vector signals having greatly different intensities without using a conventional large-scale filter circuit.

  In FIG. 1, a symbol mapping circuit 1 maps input symbol data to an i-axis component i signal and a Q-axis component q signal, which are orthogonal unit vectors having a certain phase, and outputs them. . In this embodiment, the symbol frequency of the symbol data input to the symbol mapping circuit 1 is 4.8 kHz.

  The upsampling circuits 2 and 3 upsample the i signal and the q signal output from the symbol mapping circuit 1 by n times, respectively. In this case, the 4.8 kHz symbol data is upsampled 20 times (n = 20) to generate a 96 kHz sampling i signal and a sampling q signal.

  FIG. 3 is a diagram showing a signal after upsampling by the upsampling circuits 2 and 3. 3A shows the i signal after upsampling, and FIG. 3B shows the q signal after upsampling. FIG. 4 is a diagram showing a constellation after upsampling. As shown in FIG. 3, in up-sampling, a specific pseudo signal, that is, data in which the scalars of the i signal and the q signal are “0” is “n−1” (in this case “ 19 ") is inserted and up-sampling is performed n times. In FIG. 4, the white circle mark of the coordinate (0.0) whose scalar is “0” on both the I axis and the Q axis represents the pseudo signal in this case.

  The RRC (root raised cosine) filter circuits 4 and 5 limit the frequency band of the i and q signals in FIGS. 3 and 4, that is, the i and q signals output from the upsampling circuits 2 and 3. Outputs I and Q signals, which are baseband signals.

  FIG. 5 is a diagram illustrating the I signal and the Q signal band-limited by the RRC filter circuits 4 and 5. In FIG. 5A, IS 1 is an i signal before band limitation input from the upsampling circuit 2 to the RRC filter circuit 4, and IS 2 is a baseband I signal band-limited by the RRC filter circuit 4. In FIG. 5B, QS 1 is a q signal before band limitation input from the upsampling circuit 3 to the RRC filter circuit 5, and QS 2 is a baseband Q signal band-limited by the RRC filter circuit 5. FIG. 6 is a diagram showing a constellation of I and Q signals band-limited by the RRC filter circuits 4 and 5.

  The baseband amplifier circuits 6 and 7 amplify and output the I signal and the Q signal band-limited by the RRC filter circuits 4 and 5, respectively, by a switching operation of a semiconductor element such as a transistor. In this case, the baseband amplifier circuits 6 and 7 perform amplification without requiring a bias voltage unlike the analog amplifier circuit.

  The D / A converter circuit 8 converts the I signal and Q signal amplified by the baseband amplifier circuits 6 and 7 from digital to analog and outputs them.

  The quadrature modulator 9 includes two mixer circuits 10 and 11 and a synthesis circuit 12. The RF (high frequency) frequency oscillator 13 generates a carrier signal for modulation and inputs it to the mixer circuit 10 and the phase shifter 14 of the quadrature modulator 9. The phase shifter 14 shifts the phase of the input carrier signal by π / 2, that is, 90 °, and inputs it to the mixer circuit 11 of the quadrature modulator 9. The mixer circuit 10 mixes the I signal output from the D / A converter circuit 8 and the carrier signal output from the RF frequency oscillator 13 and inputs the mixed signal to the synthesis circuit 12. The mixer circuit 11 mixes the Q signal output from the D / A converter circuit 8 and the 90 ° shifted carrier signal output from the phase shifter 14 and inputs the mixed signal to the synthesis circuit 12. The synthesizing circuit 12 synthesizes the carrier signal modulated with the I signal and the 90 ° shifted carrier signal modulated with the Q signal. As a result, the quadrature modulator 9 outputs a modulation signal that is quadrature modulated with the 19 pseudo signals inserted between the symbol data and each symbol data.

  The RF (high frequency) power amplifier circuit 15 amplifies the power of the modulated signal output from the quadrature modulator 9 based on a preset amplification factor, and transmits the amplified signal from the antenna 16 as a transmission signal.

  The coupler 17 which is a directional coupler detects the power of the transmission signal by acquiring a part of the transmission signal by reactance coupling in the transmission path between the RF power amplifier circuit 15 and the antenna 16. Hereinafter, the signal detected by the coupler 17 is referred to as a “feedback signal”.

  The quadrature demodulator 18 includes two mixer circuits 19 and 20. The RF frequency oscillator 13 generates a local (local oscillation) signal for demodulation and inputs it to the mixer circuit 19 and the phase shifter 21 of the quadrature demodulator 18. The phase shifter 21 shifts the phase of the input local signal by π / 2, that is, 90 °, and inputs it to the mixer circuit 20 of the quadrature demodulator 18. The mixer circuit 19 mixes the feedback signal obtained from the coupler 17 and the local signal output from the RF frequency oscillator 13 to generate a feedback I signal (hereinafter referred to as “I ′ signal”) having the same phase as the transmission signal. Generate (demodulate). The mixer circuit 20 mixes the feedback signal obtained from the coupler 17 and the 90 ° -shifted local signal output from the phase shifter 21 to provide a feedback Q signal whose phase is shifted by 90 ° (hereinafter, “Q ′”). Signal)) (demodulated). As a result, the quadrature demodulator 18 separates the feedback signal, which is a part of the transmission signal obtained from the coupler 17, into the I component and the Q component and demodulates them, and uses the I ′ signal and the Q ′ signal as the demodulated signals. Output.

  The A / D converter circuit 22 converts the I ′ signal and Q ′ signal output from the quadrature demodulator 18 from analog to digital and outputs the converted signal.

  The downsampling circuits 23 and 24 downsample the digital I ′ signal and Q ′ signal output from the A / D converter circuit 22. As described above, the data transmitted by the transmission signal is upsampled by including a pseudo signal having a value of “0” in addition to the original symbol data to be transmitted. Therefore, by down-sampling the I ′ signal and the Q ′ signal, the pseudo signal is thinned out, and only the I ′ signal and the Q ′ signal near the symbol are extracted.

  The output control amplifiers 25 and 26 amplify and output the baseband I signal and Q signal band-limited by the RRC filter circuits 4 and 5. Also in this case, similarly to the baseband amplifier circuits 6 and 7, amplification is performed without requiring a bias voltage by switching operation of a semiconductor element such as a transistor.

  The delay circuit 27 delays the I signal and the Q signal output from the output control amplifiers 25 and 26 for a predetermined time and outputs them. This predetermined delay time corresponds to the delay time due to the influence of the RRC filter circuits 4 and 5, the D / A converter circuit 8, the A / D converter circuit 22, and other transmission lines including hardware and wiring. . That is, the delay circuit 27 delays the time axes of the I and Q signals output from the RRC filter circuits 4 and 5 so as to coincide with the time axes of the I ′ signal and the Q ′ signal.

  The downsampling circuits 28 and 29 downsample the I signal and Q signal output from the delay circuit 27. Also in this case, the I signal and the Q signal output from the delay circuit 27 include a pseudo signal having a value of “0” in addition to the original symbol data to be transmitted, so that the I signal By down-sampling the Q signal and the Q signal, the pseudo signal is thinned out and only the I signal and Q signal in the vicinity of the symbol are extracted.

  FIG. 7 is a diagram illustrating a constellation of a downsampled signal. In FIG. 7, white circle marks represent symbol points. In the case of FIG. 6 which is a constellation before downsampling, the vector size (scalar) varies greatly, but in the case of FIG. 7, vector scalars are concentrated near the symbol points. I understand. For example, in FIG. 7, if any two vectors are represented by a black arrow and a white arrow, these scalars have almost the same size. Further, in the constellation of FIG. 6, the pseudo signal in which the scalars of the coordinates (0, 0) of the I-axis and the Q-axis are 0 are thinned out by down-sampling and deleted from the constellation of FIG. .

  The scalar arithmetic circuit 30 calculates the magnitudes of the vectors of the I ′ signal and the Q ′ signal down-sampled by the down-sampling circuits 23 and 24. On the other hand, the scalar arithmetic circuit 31 calculates the magnitudes of the vectors of the I signal and the Q signal downsampled by the downsampling circuits 28 and 29.

The scalar arithmetic circuit 30 calculates an arithmetic mean of the square values of the amplitudes of the I ′ signal and the Q ′ signal, and calculates a scalar as a square root of the arithmetic mean by the following arithmetic expression. Similarly, the scalar arithmetic circuit 31 calculates the arithmetic mean of the square values of the amplitudes of the I and Q signals, and calculates the scalar as the square root of the arithmetic mean using the following arithmetic expression.

  The differential amplifier circuit 32 amplifies the difference between the scalar (signal intensity) calculated by the scalar arithmetic circuit 30 and the scalar (signal intensity) calculated by the scalar arithmetic circuit 31, and the difference signal (intensity difference) is amplified. Output to the low-pass filter circuit 33.

  The low-pass filter circuit 33 removes an out-of-band noise component included in the difference signal and inputs it to the baseband amplifier circuits 6 and 7 as a baseband gain feedback signal. Since the out-of-band noise component causes an increase in adjacent leakage power, it must be removed by the low-pass filter circuit 33. However, since the noise component is out of band, it is not necessary to sharpen the filter characteristics. Therefore, the delay of the low-pass filter circuit 33 is reduced, and the transmission power control can be speeded up.

  As described above, the vectors of the I ′ signal and the Q ′ signal are delayed by the influence of the transmission path, and therefore the phases of the I ′ signal and the Q ′ signal are different from the phases of the I signal and the Q signal. However, since the transmission power is controlled by comparing only the scalars of the I ′ signal and the Q ′ signal with the scalars of the I signal and the Q signal, the phases of the I ′ signal and the Q ′ signal and the phases of the I signal and the Q signal are set. There is no need to match.

  As described above, in the above embodiment, the up-sampling process is performed by inserting the pseudo signal into the I signal and the Q signal orthogonal to each other representing the symbol of the information to be transmitted by the signal strength and the phase vector. When the output signal is generated by orthogonally modulating the I signal and the Q signal, the output signal generated by the RF power amplifier circuit 15 is detected by the coupler 17 to generate a feedback signal, and the feedback signal is orthogonally demodulated. The I ′ signal having the same phase as the feedback signal and the Q ′ signal having the phase orthogonal to the feedback signal are generated, and the I signal and Q signal in the vicinity of the symbol are extracted from the up-sampled I signal and Q signal, From the 'signal and Q' signal, the I 'signal and Q' signal near the symbol are extracted, and the signal intensity of the I signal and Q signal near the symbol Controlling the power of the output signal according to the intensity difference between the signal strength of the symbol near the I 'signal and Q' signal.

  Therefore, by performing power control without being based on the envelope of the transmission power signal, it is possible to perform power control that does not depend on transmission data, and stable transmission power using a small-scale filter circuit with simple filter operation processing. In addition to shortening the time to productization, it is possible to reduce the size and price of the product.

  Further, in the above embodiment, the arithmetic mean of the square values of the amplitudes of the I and Q signals in the vicinity of the symbol is calculated, the scalar signal strength of the I and Q signals is calculated, and the I and Q in the vicinity of the symbol are calculated. Since the arithmetic mean of the square values of the amplitudes of the “signal” and “Q” signal is calculated to calculate the signal strength of the scalars of the I ′ signal and the Q ′ signal, the phase of the I ′ signal and the Q ′ signal and the I There is no need to match the phases of the signal and the Q signal, and a complicated circuit for matching the phases is not used. Therefore, the device can be further reduced in size and price.

  In the above embodiment, the time axis of the I and Q signals in the vicinity of the symbol is delayed to coincide with the time axis of the I ′ and Q ′ signals in the vicinity of the symbol, so that the delay of the feedback loop is eliminated. Thus, it is possible to control the transmission power with high accuracy by eliminating the delay error of the feedback loop.

  The above embodiments are for explaining the present invention, and the present invention is not limited to the above embodiments, and other embodiments and other embodiments that can be considered by those skilled in the art without departing from the scope of the claims. Modifications also belong to the present invention.

  For example, in FIG. 1, upsampling circuits 2 and 3 correspond to sampling means, filter means corresponds to RRC filter circuits 4 and 5, modulation means corresponds to quadrature modulator 9, and detection means corresponds to coupler 17. The demodulating means corresponds to the quadrature demodulator 18, the first extracting means corresponds to the downsampling circuits 28 and 29, the second extracting means corresponds to the downsampling circuits 23 and 24, and the delaying means is the delay circuit. 27 corresponds to the scalar arithmetic circuits 30 and 31, the differential amplifier circuit 32, and the low-pass filter circuit 33. However, the present invention is not limited to such correspondence. The D / A converter circuit 8 and the phase shifter 14 may be included in the modulation means, or the A / D converter circuit 22 and the phase shifter 21 may be included in the demodulation means. In addition to the coupler 17, various known detection means can be applied.

  In the above embodiment, the configuration is such that the downsampling process is performed in order to extract the signal in the vicinity of the symbol. However, as apparent from FIG. 6, the scalars of the signal vectors are gathered in the vicinity of the symbol. The scalar distribution may be detected, and the scalar at the maximum value of the detected distribution may be extracted.

  Further, in the above embodiment, the baseband amplifier circuit 6 calculates the arithmetic mean of the square values of the amplitudes of the two signals orthogonal to each other and calculates the square root of the arithmetic mean according to the number of arithmetic operations described above. However, the feedback signal to the baseband amplifier circuits 6 and 7 may be used without calculating the square root of the arithmetic mean.

1 Symbol mapping circuit 2, 3 Up-sampling circuit 4, 5 RRC filter circuit 6, 7 Baseband amplifier circuit 9 Quadrature modulator 15 RF power amplifier circuit 18 Quadrature demodulator 23, 24, 28, 29 Down-sampling circuit 27 Delay Circuit 30, 31 Scalar arithmetic circuit 32 Differential amplifier circuit 33 Low-pass filter circuit

Claims (8)

Sampling means for performing upsampling processing by inserting pseudo signals into mutually orthogonal I and Q signals representing symbols of information to be transmitted by signal strength and phase vectors, and the I signal upsampled by the sampling means, and A transmission power control apparatus comprising: modulation means for generating a modulation signal based on a Q signal; and power amplification means for amplifying the power of the modulation signal generated by the modulation means to generate an output signal,
Detecting means for detecting an output signal generated by the power amplifying means and generating a feedback signal;
Demodulating means for demodulating the feedback signal generated by the detecting means to generate a feedback I signal having the same phase as the feedback signal and a feedback Q signal having a phase orthogonal to the feedback signal;
First extraction means for extracting an I signal and a Q signal in the vicinity of a symbol from the I signal and the Q signal up-sampled by the sampling means;
Second extraction means for extracting a feedback I signal and a feedback Q signal in the vicinity of a symbol from feedback I signals and feedback Q signals obtained based on demodulation of the demodulation means;
The power amplification means according to the intensity difference between the signal intensity of the I signal and Q signal extracted by the first extraction means and the signal intensity of the feedback I signal and feedback Q signal extracted by the second extraction means. Control means for controlling the power of the output signal generated by
A transmission power control apparatus comprising: The control means includes
First arithmetic means for calculating the arithmetic mean of the square values of the amplitudes of the I and Q signals extracted by the first extracting means and calculating the scalar signal strength of the I and Q signals; ,
A second arithmetic unit that calculates an arithmetic mean of the square values of the amplitudes of the feedback I signal and the feedback Q signal extracted by the second extraction unit to calculate the scalar signal strength of the feedback I signal and the feedback Q signal. And a computing means of
The transmission power control apparatus according to claim 1, comprising:   Delay means for delaying the time axis of the I signal and the Q signal extracted by the first extraction means so as to match the time axis of the feedback I signal and the feedback Q signal extracted by the second extraction means; The transmission power control apparatus according to claim 1, wherein Filter means for band-limiting the I and Q signals upsampled by the sampling means;
The first extraction means performs downsampling processing on the I signal and Q signal band-limited by the filter means to extract the I signal and Q signal in the vicinity of the symbol,
The second extraction means performs a downsampling process on the feedback I signal and feedback Q signal obtained based on the demodulation to extract the feedback I signal and feedback Q signal in the vicinity of the symbol,
The transmission power control apparatus according to claim 1, wherein the transmission power control apparatus is a transmission power control apparatus. Up-sampling processing is performed by inserting pseudo signals into mutually orthogonal I and Q signals representing symbols of information to be transmitted by signal intensity and phase vectors, and a modulation signal is generated based on the up-sampling I and Q signals. A transmission power control method for generating an output signal by amplifying the power of the generated modulated signal,
Detect the generated output signal to generate a feedback signal,
Demodulating the generated feedback signal to generate a feedback I signal that is in phase with the feedback signal and a feedback Q signal that is in phase with the feedback signal;
An I signal and a Q signal in the vicinity of the symbol are extracted from the up-sampled I signal and Q signal,
Extracting the feedback I signal and feedback Q signal in the vicinity of the symbol from the feedback I signal and feedback Q signal obtained based on the demodulation;
Transmission power control characterized by controlling power of an output signal according to an intensity difference between the signal intensity of the I signal and Q signal near the symbol and the signal intensity of the feedback I signal and feedback Q signal near the symbol Method.   The arithmetic mean of the square value of the amplitude of each of the I signal and Q signal near the symbol is calculated to calculate the scalar signal strength of the I signal and Q signal, and the feedback I signal and feedback Q signal near the symbol 6. The transmission power control method according to claim 5, wherein the scalar signal strength of the feedback I signal and the feedback Q signal is calculated by calculating an arithmetic mean of square values of the respective amplitudes.   7. The transmission power control method according to claim 5, wherein a time axis of the I signal and the Q signal in the vicinity of the symbol is delayed so as to coincide with a time axis of the feedback I signal and the feedback Q signal in the vicinity of the symbol. .   The up-sampling I signal and Q signal are band-limited by filter processing, down-sampling processing is performed on the band-limited I signal and Q signal to extract the I signal and Q signal in the vicinity of the symbol, and the demodulation 8. The feedback I signal and the feedback Q signal obtained based on the above are subjected to downsampling processing to extract a feedback I signal and a feedback Q signal in the vicinity of the symbol. The transmission power control method described in 1.

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