JP2006253749A - Distortion-compensating device and method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a distortion-compensating device that is superior in distortion characteristics and a method thereof in an EER distortion compensating device for separating a vector modulation signal into an amplitude signal and a phase signal, and recombining the separated signals. <P>SOLUTION: The distortion compensating device of an EER distortion modulation amplifying system separates the vector modulation signal into amplitude signal and phase signal, and recombining the separated signals. In the device, an amplitude-correcting section 100 calculates the distortion components of an amplitude modulation output signal of a power amplifier 58 and corrects the components, a phase error calculating section 102 calculates an error component of a phase modulation output signal of the power amplifier 58, a phase correcting section 103 calculates the phase rotation amount from the corrected amplitude component and further calculates the distortion components of the phase modulation output signal of the power amplifier 58 from the phase rotation amount and the phase error components calculated by the section 102. In this way, high-accuracy distortion compensation processing can be executed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a modulation amplification apparatus having high efficiency and low distortion.

  In recent years, power amplifiers, particularly high frequency amplifiers, have been used in various portable devices. It is this power amplifier that has the highest power consumption among these devices. For this reason, the efficiency of the power amplifier greatly affects the battery life of the portable device. Therefore, high efficiency of the power amplifier is desired. As power amplifiers with high efficiency, there are power amplifiers of class C, class D, class E, class F, etc., but these are non-linear amplifiers, and can only amplify signals with a constant amplitude. However, in recent years, in order to improve the data transmission speed, the use of modulation schemes with multi-valued data is increasing. Since the envelope of the multilevel modulation signal is not constant, these nonlinear amplifiers cannot be used directly. As the data transmission rate is improved, the baseband signal band tends to be widened. However, as the band is widened, a spread scheme such as CDMA or a multicarrier such as OFDM is used as the technique. There are methods, or combinations thereof. Since these systems require high linearity, the peak factor (ratio of the average value and maximum value of the signal amplitude) is increased. However, as the peak factor increases, the operating point level of the power amplifier decreases and efficiency increases. It is necessary to operate in a low area.

As described above, in the conventional linear power amplifier, efficiency and linearity are in a trade-off relationship. As an improvement measure, there is a polar modulation method. This system can achieve both efficiency and linearity at the same time, and is generally known as EER (Envelope Eliminating And Restoration).
In this EER system, a modulation signal is once separated into phase information and amplitude information, and phase information having a constant envelope is used as an input signal of a power amplifier. Then, after the amplitude information is amplified by the amplitude component amplifier, it is recombined as a power source of the power amplifier to obtain an amplified linear signal.
However, even in this EER system, a perfect linear component cannot be obtained, and a nonlinear component is generated. Therefore, distortion occurs in the power amplifier output. In order to perform distortion compensation by suppressing this non-linear influence, a conventional EER type distortion compensation apparatus has a configuration as shown in FIG. (For example, Patent Document 1 and Patent Document 2)
The operation of the conventional EER distortion compensation apparatus will be described below with reference to FIG. The baseband (BB) input signal is mapped to a predetermined signal on the orthogonal coordinate system by the signal mapper 52. The time alignment circuit 53 aligns the mapped data as serial data in terms of time. In-phase (I) quadrature (Q) signals are filtered by BLF (band limiting filters) 54 a and 54 b, and are divided into phase / amplitude signals by a quadrature / polar coordinate converter 55. The amplitude signal is calculated by calculating the absolute value of the baseband signal, and the phase signal is calculated from the I / Q component of the baseband amplitude signal. The calculated data is a one-dimensional voltage signal with respect to the time axis for the amplitude component and a two-dimensional voltage signal for the phase component.
The divided signals are passed through the amplitude correction circuit 56 and the phase correction circuit 57, the amplitude signal is applied to the power supply voltage of the power amplifier 58, and the phase signal is applied to the input of the power amplifier 58. As a result, the power amplifier 58 combines the amplitude and phase, and the modulated signal is amplified and reproduced. The reproduced signal is transmitted to the antenna 513 as a transmission signal, taken out by the coupler 59, and phase / amplitude component information which is a nonlinear component of the output signal of the power amplifier 58 is measured by the angle measurement circuit 510 and the amplitude measurement circuit 511. . This measurement value is input to the LUT 512, and a correction value is calculated. Based on the calculated correction value, the amplitude and phase are corrected by the amplitude correction circuit 56 and the phase correction circuit 57, respectively.
The LUT 512 stores correction values (calibration data) for correcting an error from the previously calculated linear amplification characteristic with respect to the values from the maximum to the minimum of the output signal of the power amplifier 58 for each phase / amplitude signal. Yes. When a phase / amplitude difference component is generated in the output signal of the power amplifier 58, the amplitude value and phase of the input signal of the power amplifier 58 are corrected by the amplitude correction circuit 56 and the phase correction circuit 57 based on this correction value. This cancels out the differential component. Therefore, an output with improved distortion characteristics can be obtained. A method for calculating calibration data is disclosed in detail in (Patent Document 1).
As described above, the EER distortion compensation circuit according to the related art corrects the phase signal and the amplitude signal at the same time as in a general power amplifier.
JP-T-2004-501527 Japanese translation of PCT publication No. 2002-500846

However, in the phase correction method of the conventional EER distortion compensation device that performs phase correction simultaneously with amplitude, the actual phase correction value is the target correction value because of the amount of phase rotation caused by the correction of the amplitude modulation signal. Does not match. This is because when the amplitude modulation signal is input to the power supply voltage, which is a characteristic of the EER method, due to the gain characteristic with respect to the power supply voltage (drain voltage) of the power amplifier, the amount of phase rotation is corrected when the input amplitude modulation signal is corrected. Because it will change. Accordingly, the phase characteristic cannot be corrected accurately simultaneously with the amplitude correction, and an error occurs in the phase correction value.
Hereinafter, the problem of the phase correction operation will be described in detail with reference to FIG. 6 based on the gain characteristic with respect to the power supply voltage (drain voltage) of the power amplifier.
FIG. 6A shows an example of the actual characteristic of the gain characteristic with respect to the power supply voltage (drain voltage) of the power amplifier. As shown by this characteristic, since the actual characteristic of the gain characteristic is not linear, it is necessary to calculate a correction characteristic that is an inverse characteristic of the actual characteristic in order to linearize the gain characteristic. In this example, the gain characteristic in the correction characteristic needs to be smaller than the gain in the actual characteristic as shown in FIG. Therefore, in order to lower the gain, the corrected power supply voltage (drain voltage) applied to the power amplifier becomes smaller than the actual characteristic.

Next, phase characteristic correction will be considered. FIG. 6B shows the phase characteristics with respect to the power supply voltage (drain voltage) of the power amplifier. As shown in this characteristic, the phase characteristic of the power amplifier can be uniquely determined by the power supply voltage. However, as shown in FIG. 6A, it should be noted that the power supply voltage (drain voltage) of the previously calculated correction value of the amplitude voltage is changed (decreased) compared to before the correction. I must. As described above, it is clear that the phase data cannot be calculated unless the power supply voltage (drain voltage) corresponding to the amplitude value (gain characteristic) of the power amplifier is determined, and at the same time, compensation is performed. If applied, the correction data is changed. Accordingly, the correction of the phase signal cannot be performed as long as it is not determined with respect to the corrected amplitude signal level.
SUMMARY OF THE INVENTION An object of the present invention is to solve the above-described conventional problems in a distortion compensation device for an EER voltage amplifier and to provide an excellent distortion compensation device and method capable of performing phase correction with high accuracy.

In order to solve the conventional problem, a separation unit that separates an amplitude signal and a phase signal from an input signal to a power amplifier, an extraction unit that extracts an amplitude signal component and a phase signal component from an output signal of the power amplifier, Based on difference information between the extracted amplitude signal component and the separated amplitude signal, amplitude correction means for correcting the separated amplitude signal, and the difference between the extracted phase signal component and the separated phase signal component Phase correction means for correcting the separated phase signal based on the information and the phase rotation information calculated from the corrected amplitude signal, and correcting the phase signal based on the corrected amplitude signal. Uses a characteristic configuration. Therefore, the phase correction value after amplitude correction can be made to exactly match the target correction value.
According to the present invention, the separating unit separates the amplitude signal and the phase signal from the input signal to the power amplifier, and the extracting unit extracts the amplitude signal component and the phase signal component from the output signal of the power amplifier. The amplitude correcting means corrects the separated amplitude signal based on the difference information between the extracted amplitude signal component and the separated amplitude signal, and the phase correcting means is separated from the extracted phase signal component. And correcting the separated phase signal based on the phase rotation information calculated from the difference information with the corrected phase signal component and the corrected amplitude signal, and the phase signal based on the corrected amplitude signal. Take steps to correct Therefore, the phase correction value after amplitude correction can be made to exactly match the target correction value.
The present invention also provides a separating means for separating an amplitude signal and a phase signal from an input signal to the power amplifier, an extracting means for extracting a phase signal component from the output signal of the power amplifier, and an output signal of the power amplifier. Based on the difference information between the extracted amplitude signal component and the separated amplitude signal, the amplitude signal extracting unit that extracts the amplitude signal component by removing the phase signal component is corrected. The phase correction information input to the phase shift means includes difference information between the extracted phase signal component and the separated phase signal, and an amplitude correction means and a phase shift means for correcting the separated phase signal. And a configuration characterized in that the information is based on phase rotation information calculated from the corrected amplitude signal. Therefore, since this configuration can be realized with an analog circuit configuration, the phase correction value after amplitude correction can be made to coincide with the target correction amount without providing an advanced numerical operation signal processing unit.

According to the distortion compensation apparatus and the distortion compensation method of the present invention, the phase signal component is corrected based on the amplitude correction value applied to the amplifier. Therefore, the phase correction value after the amplitude correction is used as the target correction amount. It becomes possible to make it correspond exactly. Therefore, highly accurate phase correction is possible.
In addition, according to the distortion compensation apparatus and the distortion compensation method of the present invention, the analog signal processing unit performs linear compensation of the amplitude and phase characteristics in the power amplifier, so that an inexpensive numerical computation signal processing unit is not provided. The distortion characteristics can be improved with a simple configuration.

  In the present invention, the distortion characteristics are improved by providing the conventional EER distortion compensation apparatus with the phase characteristic correction apparatus and method based on the corrected amplitude signal.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of the first embodiment of the distortion compensation apparatus of the present invention. Here, the part cut out from the orthogonal / polar converter 55 of FIG. 5 used in the description of the conventional example is described. In this embodiment, B.I. B. The configuration and operation from the (baseband) input to the orthogonal / polar converter 55 are the same as those in FIG. Further, in addition to the same blocks (designated by the same numbers) as those already described in the conventional configuration (FIG. 5), the amplitude correction unit 100, the phase amplitude component extraction unit 101, the phase error calculation unit 102, respectively indicated by broken lines, The phase correction unit 103 is configured. Further, AD converters (AD) 11 and 110, DA converters (DA) 14 and 113, a current amplifier 15, a mixer 114, and a local oscillator (Lo) 115 are provided as additional circuits.
The amplitude correction unit 100 includes a delay unit 12, a delay unit 17, an adder 18, a look-up table (LUT) 19, and an adder 13, and correction processing for the output amplitude value of the power amplifier 58. To do. The phase amplitude component extraction unit 101 includes an orthogonal / polar converter 117 and AD converters (AD) 118 and 119, and performs an extraction process of the amplitude value and phase of the output signal. The phase error calculation unit 102 includes a delay unit 120 and an adder 121, and performs processing for calculating an error value of the extracted phase. The phase correction unit 103 includes a delay unit (delay) 111, a look-up table (LUT) 122, and an adder 112, and performs processing for calculating a phase correction value from the calculated amplitude correction value and phase error value. .
The operation of the distortion compensating apparatus configured as described above will be described in detail with reference to FIGS. FIG. 2 shows an execution procedure of the distortion compensation method of the present invention. The procedure of FIG. 2 will be described below.

First, as in the conventional example, a vector modulation signal is generated (step 200) and separated into phase information and amplitude information (step 201). The amplitude level of the separated signal is calculated (step 202). On the other hand, in step 203, phase / gain information of the power amplifier output signal is extracted. An error value between the extracted amplitude information and the amplitude value previously calculated in step 202 is calculated (step 204). Based on the error value, an amplitude correction value is obtained from the gain characteristic described in FIG. Calculated (step 205). The calculated amplitude correction value is applied to the power supply unit of the power amplifier (step 210), and amplitude modulation is performed. Then, the gain characteristic is updated based on the amplitude correction value (step 211). On the other hand, error information between the phase information extracted in step 203 and the phase information separated in step 201 is calculated (step 207). Based on the phase error information and the amplitude correction value calculated in step 205, the phase rotation amount in the power amplifier for the amplitude correction value is calculated (step 206). This phase rotation amount is subtracted from the separated phase information, and a phase correction value is calculated from the phase characteristics described with reference to FIG. 6B based on the subtraction value (step 208). The calculated phase correction value is applied to the input of the power amplifier (step 209). Then, the phase characteristic is updated based on the phase correction value (step 211).
The operation of the first embodiment of the distortion compensating apparatus according to the present invention will be described with reference to FIG.
The analog amplitude information of the baseband signal subjected to phase / amplitude separation by the quadrature / polar modulator 55 (step 201) is converted into a digital signal by the analog-to-digital converter (AD) 11, and the amplitude level is calculated (step 202). Then, the signal is corrected through a delay circuit (delay) 12 and an adder circuit 13 (steps 204 and 205), converted into an analog signal by a digital-analog converter (DA) 14 and input to the current amplifier 15. Since the correction operation is a feedback loop, it will be described later. Since the current amplifier 15 operates as a power source of the power amplifier 58, that is, a current supply source, and the power supply voltage is an amplitude component of the modulation signal that is the output of the power amplifier 58, the output signal of the power amplifier 58 is amplitude-modulated (step 210). . On the other hand, the phase / amplitude separated analog phase signal (step 201), which is the phase information of the baseband signal, is converted into a digital signal by the AD 110 and corrected through the delay circuit 111 and the adder 112 (steps 206, 207, 208). ), And is converted into an analog signal by the DA converter 113. Since the correction operation is a feedback loop, it will be described later. Further, the signal is up-converted by a mixer 114 by a local oscillator (Lo source) 115 and converted into a radio frequency (RF) signal. The converted signal is applied to the RF input terminal of the power amplifier 58 (step 209). The signal EER-modulated by the power amplifier 58 is output to the antenna 513 and distributed by the coupler 59, and is separated into an amplitude signal and a phase signal by the quadrature / polar converter 117.

Hereinafter, each correction operation will be described using the amplitude and phase signal information separated after the EER modulation output and fed back to the input of the power amplifier 58. The amplitude / phase signals separated by the quadrature / polar converter 117 are converted into digital signals by AD 118 and 119. The converted amplitude signal is amplitude corrected by the amplitude correction unit 100. The amplitude correction operation will be described. The separated input digital amplitude signal component (step 202) is compared by the adder 18 via the delay circuit 17 with the output amplitude component of the power amplifier 58 separated by the phase amplitude component extraction unit 101 (step 203). . An amplitude correction value to be corrected based on the comparison result is calculated using the gain characteristic stored in the LUT 19 (steps 204 and 205). The corrected amplitude value is updated and stored in the LUT 19 (step 211). Since step 205 is executed in the LUT 19, it is necessary to input default data as advance data. The default data can be obtained by the same means as the embodiment disclosed in the conventional example (Patent Document 1). The calculated correction value is input to the adder 13 and added to the input digital amplitude signal. The correction process for the amplitude signal is performed by the above process.
On the other hand, the digital phase signal (step 203) separated by the phase amplitude component extraction unit 101 is compared with the input digital phase signal delayed by the delay unit 120 by the adder 121 of the phase error calculation unit 102 to obtain an error (difference). ) Value is calculated (step 207), and the phase correction amount is calculated by the phase correction unit 103 (steps 206 and 208). Hereinafter, the correction operation will be described. The phase difference value is input to the LUT 122 of the phase correction unit 103. The corrected amplitude signal value output from the adder 13 is input to the LUT 122, and the phase rotation amount is calculated from the phase difference value and the corrected amplitude value (step 206), and stored and updated in the LUT 122. (Step 211). The calculated phase phase rotation amount is input to the adder 112 and added to the input digital phase signal delayed by the delay circuit 111 (step 209). The delay circuit is inserted to adjust the delay due to the feedback loop. As described above, in this embodiment, the phase rotation information stored and updated in the LUT 122 is calculated based on the corrected amplitude information.
The distortion compensation procedure in the EER system of the present invention is summarized below. As a feature, it is necessary to calculate the amplitude signal first.
(1) The step of clarifying the phase characteristic with respect to the input level of the power amplifier output and the amplitude characteristic and its inverse characteristic.
(2) Separating the modulation signal into a phase / amplitude signal.
(3) A step of calculating an amplitude level.
(4) A step of extracting amplitude and phase error information from the power amplifier output.
(5) A step of calculating an amplitude correction value from the amplitude characteristic and the inverse characteristic of (1) using the amplitude error information of (4).
(6) A step of calculating a phase rotation amount in the amplifier from the phase characteristic of (1) using the phase error information of (4) and the amplitude correction value of (5).
(7) A step of correcting the phase by subtracting the phase rotation amount of (6) from the original phase information.
Next, the procedure for calculating the amplitude correction value and the phase correction value according to the present invention will be specifically described with reference to FIG. First, FIG. 3A is an Amp characteristic with respect to an amplitude signal (Vdd) and a phase signal (phase) of a linear AMP (L.AMP), and FIG. 3B is input to a nonlinear AMP (N.L.AMP). The Amp characteristic with respect to the corrected amplitude signal (Vddhosei) and phase signal (phasehosei) is shown. The calculation procedure is as follows.
(1) A step of calculating an approximate expression of gain (gain) and phase characteristic (isou) with respect to a power supply voltage (drain voltage Vdd) of a power amplifier to be used from measured data.
(2) A step of calculating output data (Sout) when the baseband data (Sin) input to the power amplifier is input to the linear AMP (L.AMP).
(3) A step of calculating output data (Sout_hosei) when the corrected baseband input data (Sin_hosei) is inputted to the non-linear AMP (NLAMP).
(4) A step of calculating drain voltage correction data (Vdd_hosei) so that the output data are equal (Sout = Sout_hosei).
(5) A step of calculating a phase rotation amount (isou (Vdd_hosei)) with respect to the Vdd_hosei value from the approximate expression of the phase characteristic obtained in (1) and subtracting it from the original phase data.
The corrected phase data is calculated through the above steps.
Next, the calculation procedure will be specifically described using (Equation 1) to (Equation 7).
Since the absolute values of phase, phase_hosei, isou, and isou_hosei in FIG. 3 are 1, when calculating the amplitude correction value Vdd_hosei, the following (Formula 1) may be solved. By solving this (Equation 1), the amplitude correction value can be calculated.

(Equation 1)
gain (Vdd) = gain (Vdd_hosei)
In order to solve this (Equation 1), (Equation 5) is calculated from (Equation 2). (Equation 2) and (Equation 3) indicate the gain gain (Vdd) of the linear AMP and the gain gain (Vdd_hosei) of the non-linear AMP, respectively, and are expressed by polynomials having coefficients A and B. ({N} indicates the nth power).
In the following calculation, both gain / phase approximation equations are 10th order polynomials. The order of the gain / phase approximation formula can be changed in consideration of calculation accuracy and calculation speed.
(Equation 4) is obtained from the step (4), and (Equation 5) is established from this (Equation 4). The correction Vdd (Vdd_hosei) value to be applied to the power amplifier is obtained by setting the real solution of (Equation 5) to Vdd_hosei.

(Equation 2)
gain (Vdd) = A1 * Vdd

(Equation 3)
gain (Vdd_hosei) = B1 * Vdd_hosei {10} + B2 * Vdd_hosei {9} +... + B10 * Vdd_hosei + B11

(Equation 4)
gain (Vdd) = gain (Vdd_hosei)
From Equation 4,

(Equation 5)
B1 * Vdd_hosei {10} + B2 * Vdd_hosei {9} +. + 10 * Vdd_hosei + B11-A1 * Vdd = 0
Next, phase correction data is calculated. The correction phase data is obtained by calculating isou (Vdd_hosei).
isou (Vdd_hosei) is expressed by the following polynomial having a coefficient C.

(Equation 6)
isou (Vdd_hosei) = C1 * Vdd_hosei {10} + C2 * Vdd_hosei {9} +. + C10 * Vdd_hosei + C11
The phase rotation amount is calculated by substituting the Vdd_hosei value obtained in (Formula 5) into (Formula 6). The phase correction data (phase_hosei) is calculated by dividing the phase data (phase) of the original data Sin before correction by the calculated phase rotation amount. That means

(Equation 7)
phase_hosei = phase / isou (Vdd_hosei).
As described above, the amplitude correction value and the phase correction value can be calculated.
In this example, an expression of n-dimensional polynomial approximation is used, but other mathematical expressions may be used depending on the AMP characteristics. For example, logarithm, exponent, power approximation formula, etc. Further, although the 10th order is used in this description, the order can be changed as appropriate.
By calculating the amplitude and phase correction data according to the above procedure, and correcting the amplitude and phase based on the data, the output signal waveform of the power amplifier becomes as low distortion as the input signal, which is unnecessary. Since no distortion component is generated, high efficiency can be achieved.

FIG. 4 is a block diagram showing the configuration of the second embodiment of the apparatus of the present invention. In this embodiment, in addition to the same blocks (designated by the same numbers) as those already described in the conventional configuration (FIG. 5) or Embodiment 1 (FIG. 1), an amplitude correction unit 400 including an amplitude correction circuit 43, and a delay A phase correction unit 402 including a delay unit 413, a delay unit 45, a phase shifter 46, and a filter 49; a phase error component extraction unit 401 including a phase comparator 412 and a limiter 411; and a multiplier 47 and a filter 48. The amplitude component extraction unit 403 is configured.
The operation will be described below. The separated analog amplitude information is input to an amplitude correction circuit 43 configured by a differential amplifier that can be realized by an operational amplifier (OP amplifier) or the like. In the amplitude correction circuit 43, the amplitude signal component extracted from the output signal of the power amplifier 58 by the amplitude component extraction unit 403 is input, and difference information from the analog amplitude information is obtained. The amplitude signal is corrected based on the difference information. Note that the amplitude signal component of the power amplifier 58 output signal is extracted by multiplying the power amplifier 58 output signal by the phase component of the power amplifier 58 output signal extracted by the limiter 411 by the multiplier 47 and further smoothing it by the filter 48. It is obtained by removing the phase component. The corrected amplitude signal is input to the current amplifier 15 and then input to the power supply unit of the power amplifier 58. Further, the phase rotation amount is calculated from the amplitude correction information, and the calculated value is input to the phase shifter 46.
On the other hand, the phase of the separated analog phase information is corrected by the phase correction unit 402. The operation will be described below. The analog phase information is branched to the delay circuit 413, and the branched phase information is input to the phase comparator 412. The phase comparator 412 compares the phase of the phase signal extracted by removing the amplitude component from the output from the power amplifier 58 by the limiter circuit 411 and the original analog phase information. The phase error component extracted by phase comparison is smoothed by the filter 49. The smoothed phase difference signal is corrected by the phase rotation amount calculated from the amplitude correction information of the amplitude correction circuit 43 as in the first embodiment, and is input to the phase shifter 46. The calculation process of the phase rotation amount is realized by an analog arithmetic circuit typified by an OP amplifier constituting the amplitude correction circuit 43. The phase shifter 46 corrects the phase value according to the input phase correction value, and is controlled so as to cancel the phase error amount generated at the power amplifier output. The phase shifter 46 can be realized by a variable capacitance diode.
The phase-corrected analog phase information is frequency-converted into a radio frequency band (RF) signal by the Lo source 115 in the mixer 114 and input to the RF input terminal of the power amplifier 58.
With the configuration as described above, it is possible to perform the compensation operation in the analog signal unit, and therefore it is possible to improve the distortion characteristics without providing an advanced numerical arithmetic signal processing unit.

  The present invention can be applied to a high-speed and wide-band wireless data communication device used as a multilevel modulation signal having amplitude and phase information. For example, it can be applied to mobile communication base stations and terminal stations, terrestrial digital transceivers, wireless LAN base stations and terminal stations.

Block diagram for performing EER distortion compensation in the first embodiment The figure which shows the procedure for performing distortion compensation of the EER system in Example 1. FIG. 6 is a diagram for explaining a method of calculating amplitude and phase correction data in the first embodiment. Block diagram for performing EER distortion compensation in the second embodiment Block diagram for explaining a conventional EER distortion compensation technique The figure which shows the gain and phase characteristic to the power supply voltage (drain voltage) of the power amplifier

Explanation of symbols

11 Analog to Digital Converter (AD)
12 Delay Circuit 13 Adder 14 Digital to Analog Converter (DA)
15 Current Amplifier 17 Delay Circuit 18 Adder 19 LUT (Look Up Table)
110 AD converter 111 Delay circuit 112 Adder circuit 113 DA converter 114 Mixer 115 LO source (local oscillator)
117 Quadrature / Pole Converter 118 AD Converter 119 AD Converter 120 Delay Circuit 121 Adder 122 LUT
43 Amplitude correction circuit 45 Delay circuit 46 Phase shifter 47 Multiplier 48 Filter 49 Filter 411 Limiter 412 Phase comparator 413 Delay circuit 52 Signal mapper 53 Time alignment circuit 54a, 54b BLF (band limiting filter)
55 Cartesian / polar coordinate converter 56 Amplitude correction circuit 57 Phase correction circuit 58 Power amplifier 59 Coupler 510 Angle measurement circuit 511 Amplitude measurement circuit 512 LUT
513 antenna

Claims (3)

In an EER distortion compensation device for a power amplifier that separates a vector modulation signal into an amplitude signal and a phase signal and recombines them,
Separation means for separating the amplitude signal and the phase signal from the input signal to the power amplifier;
Extraction means for extracting the amplitude signal component and the phase signal component from the output signal of the power amplifier;
Amplitude correction means for correcting the separated amplitude signal based on difference information between the extracted amplitude signal component and the separated amplitude signal;
Phase correction means for correcting the separated phase signal based on difference information between the extracted phase signal component and the separated phase signal component and phase rotation information calculated from the corrected amplitude signal And
A distortion compensation apparatus that corrects a phase signal based on a corrected amplitude signal. In an EER distortion compensation method for a power amplifier that separates a vector modulation signal into an amplitude signal and a phase signal and recombines them,
A separation means for separating the amplitude signal and the phase signal from the input signal to the power amplifier;
An extraction means for extracting an amplitude signal component and a phase signal component from the output signal of the power amplifier;
A step of correcting the separated amplitude signal based on difference information between the extracted amplitude signal component and the separated amplitude signal;
Phase correction means corrects the separated phase signal based on difference information between the extracted phase signal component and the separated phase signal component and phase rotation information calculated from the corrected amplitude signal. And performing steps,
A distortion compensation method comprising correcting a phase signal based on a corrected amplitude signal. In an EER distortion compensation device for a power amplifier that separates a vector modulation signal into an amplitude signal and a phase signal by analog signal processing and combines them again.
Separation means for separating the amplitude signal and the phase signal from the input signal to the power amplifier;
Extraction means for extracting a phase signal component from the output signal of the power amplifier;
Amplitude component extraction means for removing the phase signal component extracted from the output signal of the power amplifier and extracting the amplitude signal component;
Amplitude correction means for correcting the separated amplitude signal based on difference information between the extracted amplitude signal component and the separated amplitude signal;
Phase shift means for correcting the separated phase signal,
The phase correction information input to the phase shift means is information based on difference information between the extracted phase signal component and the separated phase signal, and phase rotation information calculated from the corrected amplitude signal. A distortion compensation apparatus characterized by being provided.

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