JP2015233245A - Distortion correction device, distortion correction method, and amplification device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a distortion correction device, a distortion correction method, and an amplification device, for improving distortion correction performance without requiring enormous labor and time for adjustment.SOLUTION: A distortion correction device 1 includes: an output IQ separation part 22 for performing IQ separation of an output signal of an amplifier 10; an input IQ separation part 21 for performing IQ separation of an input signal to the amplifier 10; and correction part 23 for correcting a phase and an amplitude of the input signal on the basis of an IQ-separated signal output from the input IQ separation part 21 and the output IQ separation part 22.

Description

  The present invention relates to a distortion correction apparatus, a distortion correction method, and an amplification apparatus, and more particularly, to a distortion correction apparatus, a distortion correction method, and an amplification apparatus using the distortion correction apparatus that correct distortion generated in an output signal with respect to an input signal.

  The distortion correction device, for example, in an amplification device, causes distortion in the output signal with respect to the input signal due to nonlinear electrical characteristics such as an amplifier that is a component. Therefore, the input signal and the output signal are compared and the input signal is corrected in advance. Is used to reduce distortion. As this type of distortion correction device, for example, as disclosed in Japanese Patent Application Laid-Open No. 08-079143, a signal obtained by demodulating a transmission output signal and an input signal before correction are output and an arithmetic value is output. There is a technique that corrects distortion by collectively interpolating values and storing a distortion correction value in a memory and multiplying an input signal by a correction signal that is read out and output from the distortion correction value.

  Also, as disclosed in Japanese Patent Application Laid-Open No. 2012-105037, the input signal to the amplifier is distributed, and one of them adjusts the amplitude and phase to adjust the amplitude and phase of a feedforward distortion component described later. The other is synthesized with the main signal to be amplified to be the main signal, and the other is synthesized with the above-mentioned main signal in the opposite phase to adjust the amplitude and phase to amplify the above-mentioned feed-forward distortion component. Some output are combined. In this document, for advanced distortion correction, it is also proposed to manually adjust the amplitude and phase of a plurality of signals so as to converge the distortion of the amplifier output to a predetermined level.

Japanese Patent Application Laid-Open No. 08-079143 JP 2012-105037 A

  However, in the technique disclosed in Japanese Patent Application Laid-Open No. 2012-105037, distortion is corrected by adjusting the phase and amplitude separately. In general, when amplitude adjustment is performed, phase distortion changes. When phase adjustment is performed, amplitude distortion changes. May be possible.

  It is an object of the present invention to provide a distortion correction apparatus, a distortion correction method, and an amplification apparatus that improve distortion correction performance without requiring a great deal of labor and time for adjustment.

  The distortion correction apparatus of the present invention includes an IQ separation unit that separates an output signal of a target device into an in-phase component and a quadrature component, and an input signal to the target device based on the in-phase component and the quadrature component output from the IQ separation unit. And a correction unit that corrects the phase and amplitude.

  The distortion correction method of the present invention includes a step of separating an output signal of a target device into an in-phase component and a quadrature component, a step of outputting the in-phase component and the quadrature component of an input signal to the target device, the in-phase component, and the Correcting the phase and amplitude of the input signal based on the quadrature component.

  An amplification apparatus according to the present invention includes an amplifier, an IQ separation unit that separates an output signal of the amplifier into an in-phase component and a quadrature component, and an input to a target device based on the in-phase component and the quadrature component output from the IQ separation unit. A correction unit that corrects the phase and amplitude of the signal.

  ADVANTAGE OF THE INVENTION According to this invention, it is possible to improve the distortion correction performance which correct | amends the distortion of the output signal with respect to the input signal of an object apparatus, without requiring a lot of labor and time for adjustment.

It is a block diagram which shows the structure of the 1st Embodiment of this invention. It is a block diagram which shows an example of a structure of the correction | amendment part 23 of FIG. FIG. 3 is a block diagram illustrating an example of a configuration of a correction value calculation unit 234 in FIG. 2. It is a block diagram which shows the structure of the 2nd Embodiment of this invention. It is a block diagram which shows the structure of the 3rd Embodiment of this invention. It is a block diagram which shows an example of a structure of the correction | amendment part 33 of FIG.

(First embodiment)
FIG. 1 is a block diagram showing the configuration of the first embodiment of the present invention. In the present embodiment, an amplification apparatus including an amplifier and a distortion correction apparatus that corrects the distortion will be described as an example.

  As shown in FIG. 1, an amplifying apparatus 1 according to the first embodiment of the present invention includes an amplifier 10 and a distortion correcting apparatus 11 that corrects distortion of an output signal with respect to an input signal generated due to nonlinear electrical characteristics of the amplifier 10. It has.

  The distortion correction device 11 separates an input signal to the amplifier 10 into two components, an in-phase component (hereinafter referred to as I component) and a quadrature component (hereinafter referred to as Q component) (hereinafter referred to as IQ separation). An input IQ separation unit 21, an output IQ separation unit 22 that performs IQ separation on the output signal output from the amplifier 10, and a correction unit 23 that corrects the input signal to the amplifier 10 so as to reduce distortion. Yes.

  The input IQ separation unit 21 extracts the input signal of the amplification device 1 using, for example, a directional coupler, and performs IQ separation, for example, by phase detection, and inputs the signal to the correction unit 23. Similarly, the output IQ separation unit 22 extracts the output signal of the amplifying apparatus 1 by, for example, a directional coupler, and performs IQ separation by, for example, phase detection, and inputs it to the correction unit 23.

  The correction unit 23 holds the relationship between the phase and amplitude of the input signal and the correction value to be added to the input signal to reduce distortion, which is calculated in advance based on the nonlinear characteristics of the amplifier and updated as needed. Yes. The correction unit 23 obtains a correction value for reducing distortion from the phase and amplitude of the input signal based on the relationship, and corrects the input signal based on the obtained correction value. On the other hand, the correction unit 23 separates the distortion of the output signal with respect to the input signal into an I component and a Q component and detects each component. Then, a correction value to be added to the input signal in order to reduce distortion is calculated, and the relationship between the correction value and the amplitude and phase of the input signal is updated based on the calculated correction value.

  In the pre-distortion method, the phase and amplitude are corrected separately (two systems). Therefore, when the amplitude is corrected, the phase distortion changes. When the phase is corrected, the amplitude distortion changes. It takes time to complete the correction. By detecting distortion in the IQ-separated state as described above and calculating a correction value, it is possible to simultaneously detect distortion in the phase and amplitude and correct the input signal in one system, and correct it in a short time. Can be completed.

  FIG. 2 is a block diagram illustrating an example of the configuration of the correction unit 23 of FIG.

  As shown in FIG. 2, the correction unit 23 includes a correction matrix 231 and a correction control unit 232.

  The correction matrix 231 is matrix information indicating the relationship between the phase and amplitude of the input signal and the correction value to be added to the input signal to reduce distortion, which is calculated in advance based on the nonlinear characteristics of the amplifier 10 and the like. is there. Specifically, the correction matrix 231 is matrix information in which, for example, the amplitude and phase of the input signal and the amplitude correction value and the phase correction value for each IQ component corresponding thereto are stored.

  When the phase and amplitude of the input signal are input to the correction matrix 231, amplitude correction values and phase correction values of the I component and the Q component are output.

  Since the input signal separated by IQ is output from the input IQ separation unit 21, the input signal I and Q components of the input signal of the correction matrix 231 are input as shown in FIG. A conversion unit 2311 that converts the phase and amplitude of the signal is provided.

  When the input signal to the amplifier 10 is input to the correction control unit 232, the correction control unit 232 corrects the input signal based on the amplitude correction value and the phase correction value for each IQ component output from the correction matrix 231. The corrected input signal is output to the amplifier 10. Specifically, for example, the correction control unit 232 obtains the amplitude correction value of the input signal based on the amplitude correction value of the I component and the amplitude correction value of the Q component, and the amplitude of the input signal based on the obtained amplitude correction value. Correct. Further, the phase correction value of the input signal is obtained based on the phase correction value of the I component and the phase correction value of the Q component, and the phase of the input signal is corrected based on the obtained phase correction value.

  As illustrated in FIG. 2, the correction unit 23 further includes an output distortion detection unit 233 and a correction value calculation unit 234.

  The output distortion detection unit 233 receives an input signal to the amplifier 10 separated by the input IQ separation unit 21 and an output signal from the amplifier 10 separated by the output IQ separation unit 22.

  As shown in FIG. 2, the delay due to the amplifier and the like generated between the input signal from the input IQ separation unit 21 and the output signal from the output IQ separation unit 22 and the level difference according to the gain of the amplifier 10 are absorbed. An adjustment unit 2331 is provided. As shown in FIG. 2, the adjustment unit 2331 adjusts the timing and voltage level of the input signal from the input IQ separation unit, for example, and outputs the adjusted signal to the output distortion detection unit 233.

  The output distortion detection unit 233 detects the difference between the input signal of the I component and Q component and the output signal of the I component and Q component as output distortion for each sampling point. The detected distortion amounts of the I component and Q component are output to the correction value calculation unit 234.

  The correction value calculation unit 234 receives the distortion of each of the I component and Q component detected by the output distortion detection unit 233 and the correction value input to the correction control unit 232 at that time. Since there is a delay due to an amplifier or the like from when the correction control unit 232 controls the input signal until the result is detected by the output distortion detection unit 233, an adjustment unit 2341 for absorbing the delay is provided. Yes. The correction value calculation unit 234 calculates correction values for each of the I component and the Q component, for example, using PI control.

  FIG. 3 is a block diagram illustrating an example of the configuration of the correction value calculation unit 234 in FIG.

  As shown in FIG. 3, the distortion of the I component input from the output distortion control unit 233 is input to the PI control unit 2342, and the PI control unit 2342 outputs a PI control output for the distortion of the I component. On the other hand, the correction value of the I component input at that time is input from the adjustment unit 2341 to the correction control unit 232. These differences are calculated from the correction value calculation unit 234 as I component correction values.

  Similarly, the distortion of the Q component input from the output distortion control unit 233 is input to the PI control unit 2343, and the PI control unit 2343 outputs a PI control output for the distortion of the Q component. On the other hand, the correction value of the Q component input at that time is input from the adjustment unit 2341 to the correction control unit 232, and the difference between them is calculated as the correction value of the Q component.

  Based on the calculated I component and Q component correction values, the correction value calculation unit 234 includes a correction matrix 231 that indicates the relationship between the amplitude and phase of the input signal and the I component and Q component correction values. Update the contents.

  As described above, according to the configuration of the present embodiment, the correction matrix 231 and the correction control unit 232 form a so-called feedforward circuit, obtain correction values for the amplitude and phase of the input signal, and input the amplifier 1 The stage is corrected and controlled. The correction control unit 232 and the correction value calculation unit 234 constitute a so-called feedback circuit, detects output distortion of the amplifier 10 from each signal extracted by the input IQ separation unit 21 and the output IQ separation unit 22, and detects the amplitude of the input signal. And the correction value for the phase is updated. Since the feedforward circuit and the feedback circuit operate in conjunction with each other, the output distortion generated in the amplifier 10 is automatically corrected in real time without requiring much labor and time for adjustment, and the output signal of the amplifying apparatus 1 is corrected with respect to the input signal. Ideal output without distortion is possible.

  Further, by repeatedly operating the feedback circuit, the correction value is optimized to a non-linear electrical characteristic including individual differences and temperature characteristics of the amplifier 10, and the output signal of the amplifying apparatus 1 is set as an output signal without distortion. A correction matrix 231 is generated.

(Second Embodiment)
Next, a second embodiment of the present invention will be described.

  FIG. 4 is a block diagram showing the configuration of the second embodiment of the amplifying apparatus of the present invention.

  As shown in FIG. 4, the present embodiment includes an IQ output unit 31 that generates an expected output value of the amplifier 10 inside the amplification device 2, and outputs an input signal to the amplifier 10 from the outside of the amplification device 2. It is different from the first embodiment in that a timing trigger signal is input.

  Further, as shown in FIG. 4, the first modulator is provided with a vector modulator 32 that generates an input signal to the amplifier 10 by vector-modulating the IQ component of the output expected value output from the IQ output unit 31. Different from the embodiment.

  As shown in FIG. 4, the amplification device 2 according to the second embodiment of the present invention includes an amplifier 10, an IQ output unit 31 that generates an output expected value of the amplifier 10, and a vector modulator 32. And a distortion correction device 12 that corrects distortion of an output signal generated by nonlinear electrical characteristics.

  In the present embodiment, the expected output value of the amplifier 10 is registered in the IQ output unit 31 in advance, and the trigger signal of the pulse modulation output timing input to the IQ output unit 31 from the outside of the amplifying apparatus 2 is used as the starting point. The output unit 31 generates an output expected value of the amplifier 10. The output expected value is an IQ component that does not include distortion of the generated signal.

  The distortion correction apparatus 12 includes an IQ output unit 31, a vector modulator 32, an output IQ separation unit 22 that performs IQ separation on the output signal output from the amplifier 10, and a correction unit 23 that corrects an input signal to the amplifier 10. It has.

The output IQ separation unit 22 extracts the output signal of the amplification device 2 by, for example, a directional coupler, performs IQ separation by, for example, phase detection, and inputs the signal to the correction unit 33.
The correction unit 23 has the same configuration as that of the correction unit 23 according to the first embodiment shown in FIG. 2, and is similar to the correction unit 23 according to the first embodiment using the signal output from the vector modulator 32 as an input signal. To work.

  According to the configuration of the present embodiment described above, the expected output value of the amplifier 10 is generated inside the amplifying apparatus 2 and is vector-modulated and input to the amplifier 10 without requiring much labor and time for adjustment. Various output distortions generated in the amplifying apparatus can be automatically corrected in real time, and an ideal output without distortion can be made in the amplifying apparatus output signal with respect to the expected output value.

  In addition, the feedback circuit configured by the correction control unit 232 and the correction value calculation unit 234 is repeatedly operated to be optimized to a correction value according to nonlinear electrical characteristics including individual differences and temperature characteristics of the amplifier 10, A correction matrix 231 for generating the output signal of the amplifying apparatus 2 without distortion is generated.

(Third embodiment)
Next, a third embodiment of the present invention will be described.

  FIG. 5 is a block diagram showing the configuration of the third embodiment of the amplifying apparatus of the present invention. FIG. 6 is a block diagram showing an example of the configuration of the correction unit 33 in FIG.

  As in the second embodiment, the present embodiment includes an IQ output unit 31 that generates an expected output value of the amplifier 10 inside the amplifying apparatus 3 as shown in FIG. The difference from the first embodiment is that a trigger signal at the output timing of the input signal to the amplifier 10 is input.

  Further, as shown in FIG. 5, the present embodiment is different from the second embodiment in that there is no vector modulator and the correction unit 33 incorporates a vector modulation function.

  As shown in FIG. 5, an amplifying apparatus 3 according to the third embodiment of the present invention includes an amplifier 10, a distortion correcting apparatus 13 that corrects distortion of an output signal with respect to an input signal generated due to nonlinear electrical characteristics of the amplifier 10, and It has.

  In the present embodiment, the IQ output unit 31 generates an expected output value of the amplifier 10 using a trigger signal of the pulse modulation output timing input from the outside of the amplification device 3 to the IQ output unit 31 as a starting point. The expected output value is an IQ component that does not include distortion of the generated signal.

  The distortion correction device 13 includes an IQ output unit 31, an output IQ separation unit 22 that performs IQ separation on the output signal output from the amplifier 10, and a correction unit 33 that corrects an input signal to the amplifier 10.

  The output IQ separation unit 22 extracts the output signal of the amplification device 3 by, for example, a directional coupler, performs IQ separation by, for example, phase detection, and inputs the signal to the correction unit 33.

  As shown in FIG. 6, the correction unit 33 includes a correction matrix 331 and a correction control unit 332 that incorporates a vector modulation function.

  IQ components corresponding to the amplitude and phase of the output expected value converted by the conversion unit 2311 are output from the correction matrix 331, and the correction control unit 332 performs vector modulation and inputs to the amplifier 10.

  The correction matrix 331 is matrix information indicating the relationship between the phase and amplitude obtained by converting the output expected value and the I component and Q component to be input to the correction control unit 332 incorporating the vector modulation function. The matrix information is calculated in advance based on nonlinear characteristics of the amplifier 10 and updated as needed. Specifically, for example, matrix information in which the amplitude and phase obtained by converting the expected output value and the amplitude value and phase value for each IQ component corresponding thereto are stored.

  When the phase and amplitude obtained by converting the output expected value are input, the correction matrix 331 outputs the amplitude value and phase value of the I component and Q component input to the correction control unit 332.

  The correction control unit 332 outputs a signal generated by vector modulation to the amplifier 10 based on the amplitude value and phase value for each IQ component output from the correction matrix 331.

  As shown in FIG. 6, the correction unit 33 further includes an output distortion detection unit 233 and a correction value calculation unit 234.

  The output distortion detection unit 233 receives the I component and Q component of the expected output value output from the IQ output unit 31 and the output signal IQ-separated by the output IQ separation unit 22. The output distortion detector 233 detects the difference between the I component and Q component of the expected output value and the I component and Q component of the output signal as output distortion for each sampling point. The detected distortion amounts of the I component and Q component are output to the correction value calculation unit 234.

  As shown in FIG. 6, there is a difference in level according to the delay caused by the amplifier or the like generated between the output expected value from the IQ output unit 31 and the output signal from the output IQ separation unit 22 and the gain of the amplifier 10. An adjustment unit 2331 for absorbing is provided. For example, the adjustment unit 2331 adjusts the timing and voltage level of the input signal from the IQ output unit 31, and outputs the adjusted signal to the output distortion detection unit 233.

  The correction value calculation unit 234 inputs the I component input at that time to the correction control unit 332 incorporating the I component and Q component distortion for each sampling point detected by the output distortion detection unit 233 and the vector modulation function. And Q component as input.

  Since there is a delay due to an amplifier or the like from when a signal is input to the correction control unit 332 until the result is detected by the output distortion detection unit 233, an adjustment unit 2341 for absorbing the delay is provided. .

  The correction value calculation unit 234 has the same configuration as that of the first embodiment shown in FIG. 3. For example, using PI control, the correction value calculation unit 234 calculates correction values for each of the I component and the Q component, and calculates the calculated I component and Q Based on each component correction value, the output matrix 331 indicating the relationship between the phase and amplitude into which the output expected value is converted and the values of the I component and Q component input to the correction control unit 332 is updated.

  As described above, according to the configuration of the present embodiment, the output expected value of the amplifier 10 is generated inside the amplifying apparatus 3 and is vector-modulated and input to the amplifier 10, which is more efficient than the second embodiment. With the configuration, it is possible to automatically correct various output distortions generated in the amplifying apparatus in real time, and to realize an ideal output without distortion in the amplifying apparatus output signal with respect to the output expected value.

  In addition, the feedback circuit configured by the correction control unit 232 and the correction value calculation unit 234 is repeatedly operated to be optimized to a correction value according to nonlinear electrical characteristics including individual differences and temperature characteristics of the amplifier 10, A correction matrix 331 for generating an output signal of the amplifying apparatus 3 without distortion is generated.

  In addition, this invention is not limited only to the structure of the above-mentioned embodiment, A various change is possible.

  For example, the correction matrices 231 and 331 have been described as matrix information in which the amplitude and phase of the input signal to the amplifier 10 and the amplitude correction value and phase correction value for each IQ component corresponding thereto are stored. The amplitude and phase information of the signal may be the amplitude and phase for each IQ component of the input signal.

  Thereby, the conversion unit 2311 is not necessary, and the configuration of the correction units 23 and 33 can be simplified.

1, 2, 3 Amplifying device 10 Amplifier 11, 12, 13 Correction device 21 Input IQ separation unit 22 Output IQ separation unit 23, 33 Correction unit 231, 331 Correction matrix 232, 332 Correction control unit 233 Output distortion detection unit 234 Correction Value calculation unit 2311 Conversion unit 2331 Adjustment unit 2341 Adjustment unit 31 IQ output unit 32 Vector modulator

Claims (7)

IQ separation unit that separates the output signal of the target device into an in-phase component and a quadrature component, and correction that corrects the phase and amplitude of the input signal to the target device based on the in-phase component and the quadrature component output from the IQ separation unit And a distortion correction apparatus. An IQ separation unit for separating an input signal to the target device into an in-phase component and a quadrature component;
The correction unit includes a correction matrix that holds a relationship between the phase and amplitude of an input signal and the correction values of the in-phase component and the quadrature component of the input signal for reducing distortion. Item 2. The distortion correction device according to Item 1. The correction unit is configured to detect an output distortion of the in-phase component and the quadrature component based on the in-phase component and the quadrature component output from the IQ separation unit, and each correction based on the output distortion. The distortion correction apparatus according to claim 2, further comprising a correction value calculation unit that calculates a correction value of the value. The output unit further includes an IQ output unit that outputs an expected output value of the target device, and the correction unit has a relationship between the phase and amplitude of the expected output value and the in-phase component and the quadrature component of the input signal for reducing distortion. The distortion correction apparatus according to claim 1, further comprising a correction matrix that holds The correction unit includes: an output distortion detection unit that detects output distortion of the in-phase component and the quadrature component based on the in-phase component and the quadrature component output from an IQ separation unit; and the input signal based on the output distortion. The distortion correction apparatus according to claim 4, further comprising: a correction value calculation unit that calculates correction values of the in-phase component and the quadrature component. Separating the output signal of the target device into an in-phase component and a quadrature component; outputting the in-phase component and the quadrature component of the input signal to the target device; and inputting the input signal based on the in-phase component and the quadrature component And a step of correcting the phase and amplitude. An amplifier, an IQ separation unit that separates the output signal of the amplifier into an in-phase component and a quadrature component, and correction of the phase and amplitude of the input signal to the target device based on the in-phase component and the quadrature component output from the IQ separation unit An amplifying apparatus comprising: a correction unit that performs the correction.

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