JPH1098421A - Transmission device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power amplifier by monitoring an output power and performing a nonlinear distortion compensation operation using the output power in a transmitter provided in a communication device of a wireless communication system using a digital modulation method. It is an object of the present invention to provide means for improving the efficiency of the system. SOLUTION: A distortion compensation unit 102 generates and outputs a distortion compensation signal 103 from a transmission signal 101, a characteristic of an output amplifier 106 stored in advance, and output power information 110. The distortion compensation signal 103 is modulated into an RF signal 105 and amplified by the output amplifier 106. The power is measured by the power measuring unit 108, and the output power information 110 is output to the distortion compensating unit 1.
02 is output. As a result, it is possible to suppress the non-linear distortion component generated from the input / output characteristics of the output amplifier 106, and to improve the efficiency of power amplification.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for compensating nonlinear distortion in a transmission apparatus for digital radio communication.

[0002]

2. Description of the Related Art In recent years, research and development of a mobile communication system using a digital modulation method have been actively conducted. When a high-efficiency amplifier is used for a transmission system in order to save power of a wireless terminal, a large amount of nonlinear distortion is likely to occur. Therefore, it is necessary to compensate for the nonlinear distortion by some method. As one means, there is a method of performing nonlinear distortion compensation of amplitude and phase by referring to a distortion compensation table using the value of a transmission baseband signal.

[0003] A conventional transmitting apparatus will be described below.
FIG. 9 shows a block configuration of a conventional transmission device. In FIG. 9, a distortion compensating unit 902 uses a stored input / output characteristic of output amplifier 906 to transmit signal 90
1 is added to the opposite characteristic. Transmission signal 903 after distortion compensation
Is modulated into an RF signal 905 by the modulation unit 904.
The output amplifier 906 power-amplifies the RF signal 905 and outputs an amplified RF signal 907. The coupling unit 908 includes an amplification R
An F signal 907 is input, an output signal 909 is output, and a part thereof is fed back as a feedback RF signal 910.
Return RF signal 9 fed back from coupling section 908
Reference numeral 10 denotes a feedback baseband signal 9
It is demodulated to 12. The distortion compensator 902 includes a transmission signal 901
And an output amplifier 906 from the feedback baseband signal 912
Estimate the input / output characteristics of.

[0004]

However, in the prior art, in order to compensate for nonlinear distortion, it is necessary to always feed back an RF signal, and a simple configuration is required for the entire transmission device. However, there is a problem that a complicated feedback unit is required.

Further, in the conventional technique, when a higher efficiency configuration capable of reducing the influence of nonlinear distortion and gain change is required for the entire transmission apparatus, the feedback section of the conventional technique can be used only to improve the efficiency. There was a problem that there was a limit to the improvement of the quality.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a means for easily realizing an improvement in power amplification efficiency by monitoring output power and performing distortion compensation using the output power as a parameter.

[0007]

In order to achieve this object, a transmitting apparatus according to the present invention measures an output power by a power measuring unit at a subsequent stage of an output amplifier, manages a characteristic variation using the output power as a parameter, and performs a nonlinear operation. By performing distortion compensation, control is performed so that the output of the output amplifier becomes an appropriate signal.

In addition, a power control unit for power compensation is inserted before the output amplifier, so that the power control unit absorbs a gain change caused by an environment such as temperature.

This makes it possible to improve the characteristics of the system as a whole against the environment such as temperature.
The nonlinear distortion compensation operation can be performed with a simple configuration.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is a transmitting device provided in a communication device of a radio communication system using a digital modulation system, wherein a non-linearity is reduced by using a power information signal. A distortion compensator that outputs a compensated baseband signal, a modulator that modulates the baseband signal and outputs an RF signal, an output amplifier that power amplifies the RF signal, and an amplified power of the RF signal And a power measurement unit that outputs an output signal and the power information signal.When a simple configuration is required, for example, a nonlinear configuration of the output signal is referred to by referring to the output power information. The adaptation of the distortion compensation operation has an effect of eliminating the nonlinearity of the power amplifier with a simple configuration.

According to a second aspect of the present invention, there is provided a transmitting apparatus provided in a communication device of a wireless communication system using a digital modulation method, wherein the transmitting apparatus outputs a baseband signal whose nonlinearity is compensated for using a power information signal. A distortion compensating unit that modulates the baseband signal and outputs an RF signal;
The RF signal, a power control unit for adjusting the gain by the power information signal, an output amplifier unit for power amplifying the gain-adjusted RF signal, and measuring the power of the amplified RF signal, and the output signal And a power measurement unit that outputs the power information signal.When a simple configuration is required, the nonlinear distortion compensation operation of the output signal is adapted by referring to the output power information. In addition to eliminating the nonlinearity of the power amplifier with a simple configuration, and providing the power controller between the modulator and the output amplifier, the power controller compensates for changes in characteristics such as gain changes in the modulator. It has the action of:

According to a third aspect of the present invention, there is provided a transmitting apparatus provided in a communication device of a wireless communication system using a digital modulation method, wherein at least one of a power information signal and a feedback baseband signal is transmitted. A distortion compensating unit that outputs a baseband signal compensated for nonlinearity by using the modulating unit that modulates the baseband signal and outputs an RF signal;
The RF signal, a power control unit that adjusts the gain by the power information signal, an output amplifier unit that amplifies the power of the gain-adjusted RF signal, and the power of the amplified RF signal is measured and amplified. A power measurement unit that outputs the RF signal and the power information signal; a combiner that feeds back a part of the RF signal output from the power measurement unit; and a feedback baseband signal that feeds back the RF signal. And a demodulation unit that demodulates the signal to a power amplification amplifier by adapting the nonlinear distortion compensation operation of the output signal by referring to the output power information when a more efficient configuration is required. The power control section compensates for changes in characteristics such as gain changes in the modulation section by providing a power control section between the modulation section and the output amplifier. It has the effect that.

According to a fourth aspect of the present invention, there is provided a transmitting apparatus provided in a communication device of a wireless communication system using a digital modulation method, wherein at least one of a power information signal and a feedback baseband signal is transmitted. A distortion compensating unit that outputs a baseband signal compensated for nonlinearity by using the modulating unit that modulates the baseband signal and outputs an RF signal;
The RF signal, a power control unit that adjusts the gain by the power information signal, an output amplifier unit that amplifies the power of the gain-adjusted RF signal, and the power of the amplified RF signal is measured and amplified. A power measurement unit that outputs the RF signal and the power information signal; a combiner that feeds back a part of the RF signal output from the power measurement unit; And a demodulation unit for demodulating the output of the AGC amplifier to the feedback baseband signal. When a more efficient configuration is required, the transmission power information is output. By adapting the nonlinear distortion compensation operation of the output signal with reference, the nonlinearity of the power amplifier is eliminated, and the power control unit is placed between the modulation unit and the output amplifier. With the provision, the power control unit compensates for changes in characteristics such as a gain change of the modulation unit, and the insertion of an AGC amplifier in the feedback unit causes unstable operation or the influence of the power control unit due to a decrease in the gain of the output amplifier. Has the effect of preventing

According to a fifth aspect of the present invention, there is provided a transmitting apparatus provided in a communication device of a wireless communication system using a digital modulation system, wherein the table stores data for compensating for nonlinearity, and the power information signal includes A distortion compensator for outputting a baseband signal whose nonlinearity has been compensated using the data of the corresponding table;
A modulator that outputs an F signal, an output amplifier that amplifies the power of the RF signal, and a power measuring unit that measures the power of the amplified RF signal and outputs an output signal and the power information signal. A transmission device equipped with a simple configuration that eliminates nonlinearity of a power amplification amplifier with a simple configuration by adapting a nonlinear distortion compensation operation of an output signal with reference to output power information when a simple configuration is required. It has the effect of doing.

According to a sixth aspect of the present invention, there is provided a transmitting apparatus provided in a communication device of a wireless communication system using a digital modulation system, wherein a table for storing data for compensating for nonlinearity and a power information signal are provided. A distortion compensator for outputting a baseband signal whose nonlinearity has been compensated using the data of the corresponding table;
A modulation unit that outputs an F signal, a power control unit that adjusts the gain of the RF signal by the power information signal, and an output amplifier unit that amplifies the power of the RF signal whose gain has been adjusted,
It is a transmission device having a power measurement unit that measures the power of the amplified RF signal, and outputs an output signal and the power information signal, such as when a simple configuration is required,
By adapting the nonlinear distortion compensation operation of the output signal with reference to the output power information, the nonlinearity of the power amplifier is eliminated with a simple configuration, and a power control unit is provided between the modulation unit and the output amplifier. Accordingly, the power control unit compensates for a change in characteristics such as a gain change of the modulation unit.

According to a seventh aspect of the present invention, there is provided a transmitting apparatus provided in a communication device of a wireless communication system using a digital modulation system, wherein a table for storing data for compensating for nonlinearity, a power information signal, A distortion compensating unit that outputs a baseband signal whose nonlinearity has been compensated using data in the table corresponding to at least one of the feedback baseband signal and a signal that modulates the baseband signal and outputs
A modulation unit that outputs an F signal, a power control unit that adjusts the gain of the RF signal by the power information signal, and an output amplifier unit that amplifies the power of the RF signal whose gain has been adjusted,
A power measuring unit that measures the power of the amplified RF signal and outputs the amplified RF signal and the power information signal, and feeds back a part of the RF signal output from the power measuring unit. Combiner, is a transmission device including a demodulation unit that demodulates the feedback RF signal to the feedback baseband signal, such as when a more efficient configuration is required, by referring to the output power information By adapting the nonlinear distortion compensation operation of the output signal, the nonlinearity of the power amplifier is eliminated, and by providing the power control unit between the modulator and the output amplifier, characteristics such as gain change of the modulator can be reduced. This has the effect that the power control unit compensates for the change.

According to an eighth aspect of the present invention, there is provided a transmitting apparatus provided in a communication device of a wireless communication system using a digital modulation system, wherein the table stores data for compensating for nonlinearity, and a power information signal. A distortion compensating unit that outputs a baseband signal whose nonlinearity has been compensated using data in the table corresponding to at least one of the feedback baseband signal and a signal that modulates the baseband signal and outputs
A modulation unit that outputs an F signal, a power control unit that adjusts the gain of the RF signal by the power information signal, and an output amplifier unit that amplifies the power of the RF signal whose gain has been adjusted,
A power measuring unit that measures the power of the amplified RF signal and outputs the amplified RF signal and the power information signal, and feeds back a part of the RF signal output from the power measuring unit. A transmitter that includes a coupler, an AGC amplifier that adjusts a gain of the RF signal that is fed back by the power information signal, and a demodulation unit that demodulates an output of the AGC amplifier into the feedback baseband signal. In cases such as when a highly efficient configuration is required, the nonlinearity of the power amplifier is eliminated by adapting the nonlinear distortion compensation operation of the output signal with reference to the output power information. By providing the power control unit, the power control unit compensates for changes in characteristics such as a gain change in the modulation unit, and the output A It has the effect of preventing the influence of the unstable operation or power control unit coming from the gain reduction of the flops.

FIG. 1 shows an embodiment of the present invention.
This will be described with reference to FIG. (Embodiment 1) FIG. 1 is a circuit block diagram of a transmitter for performing nonlinear distortion compensation according to an embodiment of the present invention. In FIG. 1, 101 is a transmission signal, 102 is a distortion compensator, 1
03 is a distortion compensation signal, 104 is a modulation unit, 105 is an RF signal, 106 is an output amplifier, 107 is an amplified RF signal, 10
8 is a power measuring unit, 109 is an output signal, and 110 is output power information.

The operation of the transmitting apparatus configured as described above will be described with reference to FIG.

The distortion compensator 102 generates and outputs a distortion compensation signal 103 from the transmission signal 101, the characteristics of the output amplifier 106 stored in advance, and the output power information 110. The modulator 104 modulates the distortion compensation signal 103 and outputs an RF signal 105 that is a carrier band signal. The output amplifier 106 power-amplifies the RF signal 105 and outputs an amplified RF signal 107. The power measuring unit 108 outputs the amplified RF signal 107 as an output signal 109, performs power measurement on the amplified RF signal 107, and outputs output power information 110.

The distortion compensating unit 102 performs distortion compensation while estimating the input / output characteristics of the output amplifier 106 from the transmission signal 101 and the output power information 110. This compensation method uses pre-acquired data in a table form. A method of managing and input / output characteristics are converted into mathematical formulas, and output power information 110 and transmission signal 1
For example, there is a method of deriving a compensation coefficient from 01.

In the present embodiment, the input / output characteristics of the output amplifier 106 are stored in the distortion compensator 102 in advance. This input / output characteristic is affected by fluctuations in power supply voltage and temperature,
Particularly large fluctuations appear as changes in the gain of the amplifier. Therefore, it is possible to estimate the characteristics by monitoring the output power. Therefore, the distortion compensating section 102 stores the change in these characteristics using the output power as a parameter.

In the conventional non-linear distortion compensation technique, a change in the gain of the output amplifier 106 due to a decrease in the power supply voltage or a rise in temperature is compensated for by a feedback loop. Therefore, a circuit for feeding back the amplifier output value is required. Yes, the configuration was complicated. According to the present embodiment, by setting the environmental change in the distortion compensating unit 102 in advance, it is possible to suppress the rise of the distortion component caused by the input / output characteristics of the output amplifier 106, and to improve the efficiency with a very simple configuration. It is possible to realize a transmission device with good performance.

(Embodiment 2) FIG. 2 is a circuit block diagram of a transmission apparatus for performing nonlinear distortion compensation according to an embodiment of the present invention. 2, reference numeral 201 denotes a transmission signal, 202 denotes a distortion compensation unit, 203 denotes a distortion compensation signal, 204 denotes a modulation unit, and 20 denotes a transmission unit.
5 is an RF signal, 206 is a power control unit, 207 is a power control RF signal, 208 is an output amplifier, 209 is an amplified RF signal, 210 is a power measurement unit, 211 is an output signal, and 212 is output power information.

The operation of the transmitting apparatus configured as described above will be described with reference to FIG.

The distortion compensating section 202 generates and outputs a distortion compensating signal 203 from the transmission signal 201, the characteristics of the output amplifier 208 stored in advance, and the output power information 212. The modulation section 204 modulates the distortion compensation signal 203 and outputs an RF signal 205 that is a signal in the carrier band. The power control section 206 adjusts the power of the power control RF signal 207 based on the output power information 212. The output amplifier 208 power-amplifies the power control RF signal 207 and outputs the amplified RF signal 209.
Is output. The power measurement unit 210 outputs the amplified RF signal 209
Is output as an output signal 211, the power is measured, and output power information 212 is output.

The distortion compensator 202 performs distortion compensation while estimating the input / output characteristics of the output amplifier 208 from the transmission signal 201 and the output power information 212. This compensation method uses compensation coefficient data taken in advance. There are a method of managing the input and output characteristics in the form of a table, a method of formulating input / output characteristics, and deriving a compensation coefficient from the output power information 212 and the transmission signal 201.

In the present embodiment, the input / output characteristics of the output amplifier 208 are stored in the distortion compensating section 202 in advance. This input / output characteristic is affected by fluctuations in power supply voltage and temperature,
Particularly large fluctuations appear as changes in the gain of the amplifier. Therefore, it is possible to estimate the characteristics by monitoring the output power. Therefore, the distortion compensating unit 202 stores the change in these characteristics using the output power as a parameter.

The power control unit 206 outputs the output power information 212
Is monitored and the gain is controlled so that the power becomes constant. In this control, if the modulation unit 204 and the like are designed to absorb changes in characteristics such as gain depending on the environment, the distortion compensation unit 202 may be operated to compensate only for the characteristics of the output amplifier 208. Is affected by factors such as a decrease in the gain of the output amplifier 208, for example, the distortion compensating unit 202
It is necessary to take into account the change in When these factors cause deterioration, for example, the power control unit 206 may be operated only for a certain period of time, such as when the power is turned on, or may use the fact that the average power is almost constant. , Or a method of maintaining the difference between the signal power of the power control RF signal 207 and the output power information 212.

In this embodiment, the power control section 206 is inserted before the output amplifier 208 so that the modulation section 204
It is possible to obtain a stable effect even with respect to the fluctuation of the gain caused by the above.

In the conventional non-linear distortion compensation technique, a change in the gain of the output amplifier 208 due to a drop in the power supply voltage or a rise in temperature is compensated by a feedback loop, so that a circuit for feeding back the output value of the amplifier is required. Yes, the configuration was complicated. According to the present embodiment, by setting the environmental change in the distortion compensating unit 202 in advance, it is possible to suppress an increase in the distortion component caused by the input / output characteristics of the output amplifier 208, and to use a very simple configuration. It is possible to realize an efficient transmission device.

(Embodiment 3) FIG. 3 is a circuit block diagram of a transmission apparatus for performing nonlinear distortion compensation according to an embodiment of the present invention. 3, reference numeral 301 denotes a transmission signal, 302 denotes a distortion compensation unit, 303 denotes a distortion compensation signal, 304 denotes a modulation unit, and 30 denotes a transmission unit.
5 is a modulation signal, 306 is a power control unit, 307 is a power control RF signal, 308 is an output amplifier, 309 is an amplified RF signal, 310 is a power measurement unit, 311 is an RF signal, 312 is a coupling unit, 313 is an output signal, 313 is an output signal, 314 is a feedback RF signal, 3
15 is a demodulation unit, 316 is a feedback baseband signal, 317
Is output power information.

The operation of the transmitting apparatus configured as described above will be described with reference to FIG.

The distortion compensator 302 generates and outputs a distortion compensation signal 303 from the transmission signal 301, the characteristics of the output amplifier 308 stored in advance, and the output power information 317. Modulating section 304 modulates distortion compensation signal 303 and outputs modulated signal 305 which is a signal in the carrier band, and power control section 306 adjusts the power of power control RF signal 307 according to the state of output power information 317. . Output amplifier 308
Power-amplifies the power control RF signal 307 and outputs an amplified RF signal 309. Power measuring section 310 outputs amplified RF signal 309 as RF signal 311, measures the power thereof, and outputs output power information 317. The coupling unit 312 outputs the RF signal 311 as an output signal 313, and feeds back a part of the RF signal 311 as a feedback RF signal 314. Feedback RF signal 314 fed back
Is returned by the demodulation unit 315 to the feedback baseband signal 316.
Is demodulated. The distortion compensator 302 includes a transmission signal 301,
From the feedback baseband signal 316 and the output power information 317, the input / output characteristics of the output amplifier 308 are estimated and updated.

The distortion compensator 302 outputs the output power information 317
The input / output characteristics of the output amplifier 308 are estimated from the transmission signal 301 and the feedback baseband signal 316 to perform distortion compensation. In this compensation method, compensation coefficient data taken in advance is managed in a table form. Or a method of formulating input / output characteristics and deriving a compensation coefficient from output power information 317 and transmission signal 301.

In the present embodiment, the distortion compensation is updated using the output power information 317. Needless to say, the correlation between the feedback baseband signal 316 and the output power information 317 is high. Distortion compensation can be performed using at least one of the power information 317 and the feedback baseband signal 316. If both are used, distortion compensation for obtaining a more efficient configuration can be performed.

It is not always necessary to store a large amount of input / output characteristic data of the output amplifier 308 in the distortion compensator 302 in advance. In the present embodiment, since the input / output characteristics are affected by fluctuations in the power supply voltage and temperature, and particularly large fluctuations appear as changes in the gain of the amplifier, it is necessary to estimate the input / output characteristics by monitoring the output power. Is possible. Therefore, the distortion compensator 302 stores only the change in these characteristics with the output power as a parameter. At the time of updating, taking into account that the input / output characteristics of the output amplifier 308 do not greatly change abruptly, a method of updating only the difference that has changed from the basic characteristics may be introduced. By doing so, it is possible to limit the update portion, so that there is a feature that high-speed convergence can be obtained.

The power control unit 306 outputs the output power information 317
Is monitored and the gain is controlled so that the power becomes constant. In this control, if the modulator 304 and the like are designed to absorb changes in characteristics such as gain depending on the environment, the distortion compensator 302 may be operated to compensate only for the characteristics of the output amplifier 308. Is affected by factors such as a decrease in the gain of the output amplifier 308, for example, the distortion compensation unit 302
It is necessary to take into account the change in In the case where these factors cause deterioration, for example, the power control unit 306 controls the power of the modulated signal 305 by operating only for a certain period of time, such as when the power is turned on, or utilizing the fact that the average power is almost constant. There are methods such as keeping the operation at a constant level and maintaining the difference between the signal power of the power control RF signal 307 and the output power information 317.

In this embodiment, the power control section 306 is inserted before the output amplifier 308 so that the modulation section 304
In this case, since the fluctuation of the gain caused by the above does not affect the distortion compensating unit 302, it is possible to stably estimate and update the distortion compensation.

In the conventional non-linear distortion compensation technique, a change in the gain of the modulation section 304 due to a decrease in the power supply voltage or a rise in temperature, etc.
This is recognized as a change in the gain of the output amplifier 308, and there is a problem in that there is a limit to stabilization and efficiency improvement of the entire device. According to the present embodiment, the modulation unit 3
Since the power control unit 306 absorbs the change in the characteristics of the modulation unit 04, it is possible to stabilize the operation and improve the efficiency even when the characteristics of the modulation unit 304 tend to change when the power is turned on.

(Embodiment 4) FIG. 4 is a circuit block diagram of a transmitter for performing nonlinear distortion compensation according to an embodiment of the present invention. 4, reference numeral 401 denotes a transmission signal, 402 denotes a distortion compensation unit, 403 denotes a distortion compensation signal, 404 denotes a modulation unit, and 40 denotes
5 is an RF signal, 406 is a power control section, 407 is a power control RF signal, 408 is an output amplifier, 409 is an amplified RF signal, 410 is a power measurement section, 411 is an RF signal, 412 is a coupling section, 413 is an output signal, 414 is a feedback RF signal, 4
15 is an AGC amplifier, 416 is a power control feedback signal, 41
7 is a demodulation unit, 418 is a feedback baseband signal, and 419 is output power information.

The operation of the transmitting apparatus configured as described above will be described with reference to FIG.

The distortion compensating section 402 outputs the transmission signal 401, the stored characteristics of the output amplifier 408, and the output power information 4.
19, a distortion compensation signal 403 is generated and output. Modulation section 404 modulates distortion compensation signal 403 and outputs modulated signal 405 that is a carrier band signal.
6 is a power control RF according to the state of the output power information 419.
The power of the signal 407 is adjusted. The output amplifier 408 power-amplifies the power control RF signal 407 and outputs the amplified RF signal 407.
9 is output. The power measuring unit 410 outputs the amplified RF signal 40
9 is output as an RF signal 411, the power is measured, and output power information 419 is output. Coupling part 41
2 outputs the RF signal 411 as an output signal 413,
A part thereof is fed back as a feedback RF signal 414. The feedback RF signal 414 fed back is
The C amplifier 415 controls the gain according to the output power information 419 and outputs a power control feedback signal 416.
The power control feedback signal 416 is demodulated by the demodulation unit 417 into a feedback baseband signal 418. Distortion compensator 402
Is the transmission signal 401 and the feedback baseband signal 418
And the output power information 419, the input / output characteristics of the output amplifier 408 are estimated and updated.

The distortion compensator 402 outputs the output power information 419
, The input / output characteristics of the output amplifier 408 are estimated from the transmission signal 401 and the feedback baseband signal 418 to perform distortion compensation. This compensation method manages compensation coefficient data taken in advance in a table form. Or a method of deriving a compensation coefficient from the output power information 419 and the transmission signal 401 by converting the input / output characteristics into a mathematical expression.

In this embodiment, the distortion compensation is updated using the output power information 419. Needless to say, the correlation between the feedback baseband signal 418 and the output power information 419 is high. It is possible to perform distortion compensation using at least one of the power information 419 and the feedback baseband signal 418, and if both are used, it is possible to perform distortion compensation for obtaining a more efficient configuration.

It is not always necessary to store a large amount of input / output characteristic data of the output amplifier 408 in the distortion compensator 402 in advance. In the present embodiment, since the input / output characteristics are affected by fluctuations in the power supply voltage and temperature, and particularly large fluctuations appear as changes in the gain of the amplifier, it is necessary to estimate the input / output characteristics by monitoring the output power. Is possible. Therefore, in the distortion compensating unit 402, only the change in these characteristics is stored with the output power as a parameter. At the time of updating, taking into account that the input / output characteristics of the output amplifier 408 do not suddenly change significantly, a method of updating only the difference that has changed from the basic characteristics may be introduced. By doing so, it is possible to limit the update portion, so that there is a feature that high-speed convergence can be obtained.

The power control unit 406 outputs the output power information 419
Is monitored and the gain is controlled so that the power becomes constant. In this control, if the modulator 404 and the like are designed to absorb changes in characteristics such as gain depending on the environment, the distortion compensator 402 may be operated to compensate only for the characteristics of the output amplifier 408. Is affected by factors such as a decrease in the gain of the output amplifier 408, the distortion compensating unit 402 adds the power control unit 406 in addition to the characteristics of the output amplifier 408.
It is necessary to take into account the change in In the case where these factors cause deterioration, for example, the power control unit 406 controls the power of the modulation signal 405 by operating only for a certain period of time, such as when the power is turned on, or by utilizing the fact that the average power is almost constant. There are methods such as keeping the operation at a constant level and maintaining the difference between the signal power of the power control RF signal 407 and the output power information 419.

In this embodiment, the power control section 406 is inserted before the output amplifier 408 so that the modulation section 404
In this case, since the fluctuation of the gain generated in step (1) does not affect the distortion compensating unit 402, it is possible to stably estimate and update the distortion compensation.

Also, in this embodiment, since the AGC amplifier 415 is inserted before the demodulation unit 417, when the output of the power control unit 406 is also affected by factors such as a decrease in the gain of the output amplifier 408, There is an effect that the effect can be removed by the AGC amplifier 415.

In the conventional nonlinear distortion compensation technique, when the output of the output amplifier 408 decreases due to a factor such as the effect of the power supply voltage, the output decrease is compensated for by the compensation coefficient.
If this cannot be achieved due to a decrease in gain, the coefficient may diverge, and some countermeasures are required. In the present embodiment, even in such a case, by inserting the AGC amplifier 415, the gain reduction of the output amplifier 408 does not affect the distortion compensator 402.
A stable operation can be obtained, and efficiency can be improved.

(Embodiment 5) FIG. 5 is a circuit block diagram of a transmitter for performing nonlinear distortion compensation according to an embodiment of the present invention. 5, reference numeral 501 denotes a transmission signal, 502 denotes a distortion compensation table, 503 denotes a distortion compensation coefficient, 504 denotes a distortion compensation unit, 505 denotes a distortion compensation signal, 506 denotes a modulation unit, and 507 denotes R.
F signal, 508 is an output amplifier, 509 is an amplified RF signal,
510 is a power measuring unit, 511 is an output signal, and 512 is output power information.

The operation of the transmitting apparatus configured as described above will be described with reference to FIG.

The distortion compensator 504 outputs the distortion compensation signal 505 from the transmission signal 501 and the output power information 512 by referring to the distortion compensation coefficient 503 stored in the distortion compensation table 502 in advance. The modulation unit 506 outputs the distortion compensation signal 505
And outputs an RF signal 507 that is a carrier band signal. The output amplifier 508 amplifies the power of the RF signal 507 and outputs an amplified RF signal 509. Power measurement unit 510
Outputs the amplified RF signal 509 as an output signal 511, measures the power thereof, and outputs output power information 512.

The distortion compensation table 502 stores in advance distortion compensation coefficients having an inverse characteristic of the input / output characteristic of the output amplifier 508. The input / output characteristics are affected by fluctuations in the power supply voltage and changes in temperature, and particularly large fluctuations appear as changes in the gain of the amplifier. Therefore, it is possible to estimate the characteristics by monitoring the output power. Therefore, the distortion compensation table 502
Stores a distortion compensation coefficient using the transmission signal 501 and the output power information 512 as parameters.

In the conventional non-linear distortion compensation technique, a change in the gain of the output amplifier 508 due to a drop in power supply voltage or a rise in temperature is compensated for by a feedback loop. Therefore, a circuit for feeding back the output value of the amplifier is required. Yes, the configuration was complicated. According to the present embodiment, by setting the environmental change in the distortion compensation table 502 in advance, it is possible to suppress an increase in the distortion component caused by the input / output characteristics of the output amplifier 508, and the efficiency is improved by a very simple configuration. It is possible to realize a transmission device with good performance.

(Embodiment 6) FIG. 6 is a circuit block diagram of a transmitter for performing nonlinear distortion compensation according to an embodiment of the present invention. 6, reference numeral 601 denotes a transmission signal, 602 denotes a distortion compensation table, 603 denotes a distortion compensation coefficient, 604 denotes a distortion compensation unit, 605 denotes a distortion compensation signal, 606 denotes a modulation unit, and 607 denotes R.
F signal, 608 is a power control unit, 609 is a power control RF signal, 610 is an output amplifier, 611 is an amplified RF signal, 61
2 is a power measurement unit, 613 is an output signal, and 614 is output power information.

The operation of the transmitting apparatus configured as described above will be described with reference to FIG.

The distortion compensator 604 outputs the distortion compensation signal 605 from the transmission signal 601 and the output power information 614 by referring to the distortion compensation coefficient 603 stored in the distortion compensation table 602 in advance. The modulation unit 606 includes a distortion compensation signal 605
And outputs an RF signal 607 that is a carrier band signal, and the power control unit 608 adjusts the power of the power control RF signal 609 according to the state of the output power information 614. The output amplifier 610 power-amplifies the power control RF signal 609 and outputs an amplified RF signal 611. Power measurement unit 612
Outputs the amplified RF signal 611 as an output signal 613, measures the power thereof, and outputs output power information 614.

The distortion compensation table 602 stores in advance distortion compensation coefficients having an inverse characteristic of the input / output characteristic of the output amplifier 610. The input / output characteristics are affected by fluctuations in the power supply voltage and changes in temperature, and particularly large fluctuations appear as changes in the gain of the amplifier. Therefore, it is possible to estimate the characteristics by monitoring the output power. Therefore, the distortion compensation table 602
Stores a distortion compensation coefficient using the transmission signal 601 and the output power information 614 as parameters.

The power control unit 608 outputs the output power information 614
Is monitored and the gain is controlled so that the power becomes constant. In this control, if the modulation unit 606 or the like is designed to absorb changes in characteristics such as gain depending on the environment, the distortion compensation table 602 may store a distortion compensation coefficient for compensating only the characteristics of the output amplifier 610. Good, for example, the output amplifier 6
In the case of being affected by factors such as the gain reduction of 10, the distortion compensation table 602 needs to store the distortion compensation coefficient taking into account the change of the power control unit 608 in addition to the characteristics of the output amplifier 610. is there. In the case where these factors cause deterioration, for example, the power control unit 608 may be operated only for a certain period of time, such as when the power is turned on, or by utilizing the fact that the average power is almost constant. Of the power control RF signal 609 and the difference between the output power information 614 and the like.

In the present embodiment, the power control section 608 is inserted before the output amplifier 610 so that the modulation section 606
It is possible to obtain a stable effect even with respect to the fluctuation of the gain caused by the above.

In the conventional nonlinear distortion compensation technique, a change in the gain of the output amplifier 610 due to a drop in power supply voltage or a rise in temperature is compensated for by a feedback loop. Therefore, a circuit for feeding back the amplifier output value is required. Yes, the configuration was complicated. According to the present embodiment, by setting the environmental change as a compensation coefficient of the distortion compensating unit 602 in advance, it is possible to suppress an increase in the distortion component caused by the input / output characteristics of the output amplifier 610, which is very simple. With such a configuration, an efficient transmission device can be realized.

(Embodiment 7) FIG. 7 is a circuit block diagram of a transmission apparatus for performing nonlinear distortion compensation according to an embodiment of the present invention. 7, 701 is a transmission signal, 702 is a distortion compensation table, 703 is a distortion compensation coefficient, 704 is a distortion compensation unit, 705 is a distortion compensation signal, 706 is a modulation unit, 706 is a modulation signal, 708 is a power control unit, and 709 is a power control unit. Is a power control RF signal, 710 is an output amplifier, 711 is an amplified RF signal, 71
2 is a power measurement unit, 713 is an RF signal, 714 is a coupling unit,
715 is an output signal, 716 is a feedback RF signal, 717 is a demodulation unit, 718 is a feedback baseband signal, and 719 is output power information.

The operation of the transmitting apparatus configured as described above will be described with reference to FIG.

The distortion compensating section 704 refers to the distortion compensation coefficient 703 stored in the distortion compensation table 702 from the transmission signal 701 and the output power information 719, and
5 is output. The modulation section 706 modulates the distortion compensation signal 705 and outputs a modulation signal 707 which is a signal in the carrier band, and the power control section 708 adjusts the power of the power control RF signal 709 according to the state of the output power information 719. . The output amplifier 710 power-amplifies the power control RF signal 709 and outputs an amplified RF signal 711. Power measurement unit 712
Outputs the amplified RF signal 711 as an RF signal 713, measures its power, and outputs output power information 719. The coupling unit 714 outputs the RF signal 713 as an output signal 715, and feeds back a part of the RF signal 713 as a feedback RF signal 716. Feedback R feedback
The F signal 716 is demodulated by the demodulation unit 717 into a feedback baseband signal 718. The distortion compensating unit 704 estimates input / output characteristics of the output amplifier 710 from the transmission signal 701, the feedback baseband signal 718, and the output power information 719, and updates the contents of the distortion compensation table 702.

The distortion compensation table 702 contains the output power information 7
19, the transmission signal 701 and the feedback baseband signal 718 are stored, and the distortion of the output amplifier 710 is compensated. Needless to say, the correlation between the feedback baseband signal 718 and the output power information 719 is high. Accordingly, the distortion compensating unit 704 can update the coefficient of the distortion compensation table 702 using at least one of the output power information 719 and the feedback baseband signal 718. If both are used, higher efficiency can be achieved. Distortion compensation for obtaining a simple configuration can be performed.

The distortion compensation table 702 does not necessarily need to store a large amount of distortion compensation coefficient data having the inverse characteristic of the input / output characteristic of the output amplifier 710. In the present embodiment, since the input / output characteristics are affected by fluctuations in the power supply voltage and temperature, and particularly large fluctuations appear as changes in the gain of the amplifier, it is necessary to estimate the input / output characteristics by monitoring the output power. Is possible. Therefore, the transmission signal 701 and the output power information 719 are stored in the distortion compensation table 702 as parameters. At the time of updating, taking into consideration that the input / output characteristics of the output amplifier 710 do not change drastically,
A method of updating only a difference changed from the basic characteristic may be introduced. By doing so, it is possible to limit the update portion, so that there is a feature that high-speed convergence can be obtained.

The power control unit 708 outputs output power information 719
Is monitored and the gain is controlled so that the power becomes constant. In this control, if the modulation unit 706 or the like is designed to absorb changes in characteristics such as gain due to the environment, the distortion compensation table 702 stores a distortion compensation coefficient for compensating only the characteristics of the output amplifier 710. However, in the case of being affected by factors such as a decrease in the gain of the output amplifier 710, for example, the distortion compensation table 702 includes, in addition to the characteristics of the output amplifier 710, the distortion compensation coefficient taking into account the change of the power control unit 708. Must be stored. When these factors cause deterioration, for example, the power control unit 708 controls the power of the modulation signal 707 by operating only for a certain period of time, such as when the power is turned on, or by utilizing the fact that the average power is almost constant. There are methods such as keeping the operation at a constant level and maintaining the difference between the signal power of the power control RF signal 709 and the output power information 719.

In the present embodiment, the power control section 708 is inserted before the output amplifier 710 so that the
The distortion compensation coefficient is not affected by the fluctuation of the gain caused by the above, and the contents of the distortion compensation table 702 can be stably estimated and updated.

In the conventional nonlinear distortion compensation technique, a change in the gain of the modulation section 706 due to a decrease in the power supply voltage or a rise in temperature, etc.
This is recognized as a change in the gain of the output amplifier 710, and there is a problem in that there is a limit to stabilization and efficiency improvement of the entire device. According to the present embodiment, the modulation unit 7
Since the power control unit 708 absorbs the characteristic change of the modulation unit 06, the operation can be stabilized and the efficiency can be improved even with respect to the characteristic fluctuation of the modulation unit 706 which is likely to occur when the power is turned on.

(Embodiment 8) FIG. 8 is a circuit block diagram of a transmitting apparatus for performing nonlinear distortion compensation according to an embodiment of the present invention. 8, reference numeral 801 denotes a transmission signal, 802 denotes a distortion compensation table, 803 denotes a distortion compensation coefficient, 804 denotes a distortion compensation unit, 805 denotes a distortion compensation signal, 806 denotes a modulation unit, and 807 denotes R.
F signal, 808 is a power control unit, 809 is a power control RF signal, 810 is an output amplifier, 811 is an amplified RF signal, 81
2 is a power measurement unit, 813 is an RF signal, 814 is a coupling unit,
815 is an output signal, 816 is a feedback RF signal, and 817 is A
A GC amplifier, 818 is a power control feedback signal, 819 is a demodulation unit, 820 is a feedback baseband signal, and 821 is output power information.

The operation of the transmitting apparatus configured as described above will be described with reference to FIG.

The distortion compensating section 804 refers to the distortion compensation coefficient 803 stored in the distortion compensation table 802 from the transmission signal 801 and the output power information 821, and
5 is output. Modulating section 806 modulates distortion compensation signal 805 and outputs modulated signal 807 which is a carrier band signal, and power control section 808 adjusts the power of power control RF signal 809 according to the state of output power information 821. . Output amplifier 810 power-amplifies power control RF signal 809 and outputs amplified RF signal 811. Power measurement unit 812
Outputs the amplified RF signal 811 as an RF signal 813, measures the power thereof, and outputs output power information 821. The coupling unit 814 outputs the RF signal 813 as the output signal 815, and feeds back a part of the RF signal 813 as the feedback RF signal 816. Feedback R feedback
The F signal 816 is output from the AGC amplifier 817 to the output power information 8.
The gain is controlled according to 21 and a power control feedback signal 818 is output. The power control feedback signal 818 is demodulated by the demodulation unit 819 into a feedback baseband signal 820. The distortion compensator 804 estimates the input / output characteristics of the output amplifier 810 from the transmission signal 801, the feedback baseband signal 820, and the output power information 821, and updates the contents of the distortion compensation table 802.

The distortion compensation table 802 contains the output power information 8
21, the distortion compensation coefficient estimated from the transmission signal 801 and the feedback baseband signal 820 are stored, and the distortion of the output amplifier 710 is compensated. Needless to say, the correlation between the feedback baseband signal 820 and the output power information 821 is high. From this, the distortion compensating unit 804 can update the coefficient of the distortion compensation table 802 using at least one of the output power information 821 and the feedback baseband signal 820. Distortion compensation for obtaining a simple configuration can be performed.

The distortion compensation table 802 does not always need to store a large amount of distortion compensation coefficient data having the inverse characteristic of the input / output characteristic of the output amplifier 810. In the present embodiment, since the input / output characteristics are affected by fluctuations in the power supply voltage and temperature, and particularly large fluctuations appear as changes in the gain of the amplifier, it is necessary to estimate the input / output characteristics by monitoring the output power. Is possible. Therefore, the transmission signal 801 and the output power information 821 are stored in the distortion compensation table 802 as parameters. At the time of updating, taking into account that the input / output characteristics of the output amplifier 810 do not change drastically,
A method of updating only a difference changed from the basic characteristic may be introduced. By doing so, it is possible to limit the update portion, so that there is a feature that high-speed convergence can be obtained.

The power control unit 808 outputs the output power information 821
Is monitored and the gain is controlled so that the power becomes constant. In this control, if the modulation unit 806 or the like is designed to absorb changes in characteristics such as gain due to the environment, the distortion compensation table 802 stores a distortion compensation coefficient for compensating only the characteristics of the output amplifier 810. I just need. As a control method of the power control unit 808, for example, the power control unit 808 is operated only for a certain period of time such as when the power is turned on, or the operation is such that the power of the modulation signal 807 is maintained at a certain level by using the fact that the average power is almost constant. , The difference between the signal power of the power control RF signal 809 and the output power information 821 is held.

In the present embodiment, the power control section 808 is inserted before the output amplifier 810 so that the modulation section 806
The effect of the distortion compensation coefficient resulting from the fluctuation of the gain caused by the above is eliminated, and the content of the distortion compensation table 802 can be stably estimated and updated.

Also, in the present embodiment, since AGC amplifier 817 is inserted before demodulation section 819, when the output of power control section 808 is also affected by factors such as a decrease in the gain of output amplifier 810, There is an effect that the effect can be removed by the AGC amplifier 817.

In the conventional nonlinear distortion compensation technique, when the output of the output amplifier 810 decreases due to a factor such as the effect of the power supply voltage, the output decrease is compensated for by the compensation coefficient.
If this cannot be achieved due to a decrease in gain, the coefficient may diverge, and some countermeasures are required. In the present embodiment, even in such a case, by inserting the AGC amplifier 817, the gain reduction of the output amplifier 810 does not affect the distortion compensation coefficient of the distortion compensation table 802, so that stable operation can be obtained. Thus, efficiency can be improved.

[0080]

As described above, according to the present invention, when a simple configuration is required, the nonlinear distortion compensating operation is performed while monitoring the power change indicating the characteristic change. With the configuration, power efficiency can be improved.

Further, according to the present invention, when a more efficient configuration is required, a gain change caused by the environment and the like is absorbed by the power control unit, so that a more efficient transmission than the prior art is achieved. A device can be obtained.

[Brief description of the drawings]

FIG. 1 is a circuit block diagram of a transmission apparatus that performs nonlinear distortion compensation according to an embodiment of the present invention.

FIG. 2 is a circuit block diagram of a transmission device that performs nonlinear distortion compensation according to one embodiment of the present invention.

FIG. 3 is a circuit block diagram of a transmission device that performs nonlinear distortion compensation according to an embodiment of the present invention.

FIG. 4 is a circuit block diagram of a transmission apparatus that performs nonlinear distortion compensation according to an embodiment of the present invention.

FIG. 5 is a circuit block diagram of a transmission apparatus that performs nonlinear distortion compensation according to one embodiment of the present invention.

FIG. 6 is a circuit block diagram of a transmission device that performs nonlinear distortion compensation according to an embodiment of the present invention.

FIG. 7 is a circuit block diagram of a transmission device that performs nonlinear distortion compensation according to an embodiment of the present invention.

FIG. 8 is a circuit block diagram of a transmission device that performs nonlinear distortion compensation according to an embodiment of the present invention.

FIG. 9 is a circuit block diagram of a transmission device that performs conventional nonlinear distortion compensation.

[Explanation of symbols]

 Reference Signs List 101 transmission signal 102 distortion compensation unit 103 distortion compensation signal 104 modulation unit 105 RF signal 106 output amplifier 108 power measurement unit 110 output power information 202 distortion compensation unit 204 modulation unit 206 power control unit 208 output amplifier 210 power measurement unit 302 distortion compensation unit 304 Modulation unit 306 Power measurement unit 308 Output amplifier 310 Power measurement unit 312 Coupling unit 315 Demodulation unit 402 Distortion compensation unit 404 Modulation unit 406 Power control unit 408 Output amplifier 410 Power measurement unit 412 Coupling unit 415 AGC amplifier 417 Demodulation unit 502 Distortion compensation Table 504 Distortion compensation unit 506 Modulation unit 508 Output amplifier 510 Power measurement unit 602 Distortion compensation table 604 Distortion compensation unit 606 Modulation unit 608 Power control unit 610 Output amplifier 612 Power measurement unit 702 Distortion compensation table 704 Distortion compensation 706 modulation section 708 power control section 710 output amplifier 712 power measurement section 714 coupling section 717 demodulation section 802 distortion compensation table 804 distortion compensation section 806 modulation section 808 power control section 810 output amplifier 812 power measurement section 814 coupling section 817 AGC amplifier 819 demodulation Department

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kimihide Mihozu 4-3-1 Tsunashima, Kohoku-ku, Kawa Yokohama City, Kanagawa Prefecture Inside Matsushita Communication Industrial Co., Ltd.

Claims (8)

[Claims] 1. A transmission device provided in a communication device of a wireless communication system using a digital modulation method, comprising: a distortion compensator that outputs a baseband signal whose nonlinearity has been compensated using a power information signal; A modulator that modulates a baseband signal to output an RF signal, an output amplifier that power amplifies the RF signal, measures the power of the amplified RF signal, and outputs an output signal and the power information signal. A transmission device comprising: a power measurement unit that outputs the power. 2. A transmission device provided in a communication device of a wireless communication system using a digital modulation method, comprising: a distortion compensation unit that outputs a baseband signal whose nonlinearity has been compensated using a power information signal; A modulation unit that modulates a baseband signal to output an RF signal, a power control unit that adjusts the gain of the RF signal by the power information signal, and an output amplifier unit that amplifies the gain-adjusted RF signal, A transmitting apparatus comprising: a power measuring unit that measures the power of the amplified RF signal and outputs an output signal and the power information signal. 3. A transmitter provided in a communication device of a wireless communication system using a digital modulation method, wherein nonlinearity is compensated for using at least one of a power information signal and a feedback baseband signal. A distortion compensation unit that outputs a baseband signal, a modulation unit that modulates the baseband signal and outputs an RF signal, a power control unit that adjusts the gain of the RF signal by the power information signal, and a gain adjustment unit. An output amplifier unit that amplifies the power of the RF signal, a power measuring unit that measures the power of the amplified RF signal, and outputs the amplified RF signal and the power information signal; and A coupler that feeds back a part of the output RF signal; and a demodulator that demodulates the fed-back RF signal to the feedback baseband signal. Transmitting device. 4. A transmission device provided in a communication device of a wireless communication system using a digital modulation method, wherein nonlinearity is compensated for using at least one of a power information signal and a feedback baseband signal. A distortion compensation unit that outputs a baseband signal, a modulation unit that modulates the baseband signal and outputs an RF signal, a power control unit that adjusts the gain of the RF signal by the power information signal, and a gain adjustment unit. An output amplifier unit that amplifies the power of the RF signal, a power measuring unit that measures the power of the amplified RF signal, and outputs the amplified RF signal and the power information signal; and A combiner for feeding back a part of the output RF signal, and an AGC amplifier for adjusting the gain of the fed-back RF signal by the power information signal And a demodulator for demodulating the output of the AGC amplifier to the feedback baseband signal. 5. A transmitter provided in a communication device of a wireless communication system using a digital modulation method, comprising: a table for storing data for compensating for nonlinearity; and a table for data corresponding to a power information signal. A distortion compensator that outputs a baseband signal that compensates for non-linearity using the modulator, a modulator that modulates the baseband signal and outputs an RF signal, an output amplifier that power amplifies the RF signal, A transmission device comprising: a power measuring unit that measures the power of the RF signal and outputs an output signal and the power information signal. 6. A transmitter provided in a communication device of a wireless communication system using a digital modulation method, comprising: a table for storing data for compensating for non-linearity; and a table for data corresponding to a power information signal. A distortion compensating unit that outputs a baseband signal whose nonlinearity is compensated by using the modulating unit that modulates the baseband signal and outputs an RF signal; and a power control that adjusts a gain of the RF signal with the power information signal. Unit, an output amplifier unit for power-amplifying the gain-adjusted RF signal, and a power measuring unit for measuring the power of the amplified RF signal, and outputting an output signal and the power information signal. Transmission device. 7. A transmitting device provided in a communication device of a wireless communication system using a digital modulation method, wherein a table for storing data for compensating for nonlinearity, and a power information signal and a feedback baseband signal. A distortion compensation unit that outputs a baseband signal whose nonlinearity has been compensated using data of the table corresponding to at least one signal, a modulation unit that modulates the baseband signal and outputs an RF signal, and the RF signal A power control unit that adjusts the gain by the power information signal, an output amplifier unit that power-amplifies the gain-adjusted RF signal, and measures the power of the amplified RF signal, and the amplified RF signal A power measuring unit that outputs the power information signal and a power information signal; a coupler that feeds back a part of the RF signal output from the power measuring unit; A demodulation unit for demodulating the RF signal that has been fed back to the feedback baseband signal. 8. A transmission device provided in a communication device of a wireless communication system using a digital modulation method, wherein the table stores data for compensating for nonlinearity, and a power information signal and a feedback baseband signal. A distortion compensation unit that outputs a baseband signal whose nonlinearity has been compensated using data of the table corresponding to at least one signal, a modulation unit that modulates the baseband signal and outputs an RF signal, and the RF signal A power control unit that adjusts the gain by the power information signal, an output amplifier unit that power-amplifies the gain-adjusted RF signal, and measures the power of the amplified RF signal, and the amplified RF signal A power measuring unit that outputs the power information signal and a power information signal; a coupler that feeds back a part of the RF signal output from the power measuring unit; An AGC amplifier for adjusting the gain of the feedback RF signal by the power information signal;
A demodulator for demodulating the output of the AGC amplifier into the feedback baseband signal.