JP2005175894A - Distortion compensation amplifying device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform stable distortion compensation coping with surrounding temperature changes since the sharp reduction of a distortion compensation amount due to a temperature is noticed and the distortion compensation becomes instable in the case that there is the surrounding temperature change because the respective devices of a PD part have characteristic changes due to the temperature. <P>SOLUTION: A distortion compensation amplifying device for compensating distortion generated at the time of amplification comprises an input level detection part for detecting an input level from input signals, a distortion generation part for generating distortion offset signals which offset the distortion generated at the time of the amplification from the input signals, a distortion offset signal composite part for compositing the input signals and the distortion offset signals, an amplification part for amplifying the output of the distortion offset signal composite part, an output level detection part for detecting an output level from the output of the amplification part, and a temperature detection part for detecting a surrounding temperature, and bias control of the distortion generation part is executed corresponding to the input level detected by the input level detector and a temperature level detected by the temperature detection part. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a distortion compensation amplifying apparatus that compensates for distortion generated during amplification by a predistortion (PD) method. Moreover, the amplification device according to the present invention can be applied to, for example, a base station device or a relay amplification device provided in a wireless communication system such as a mobile communication system.

Here, as the wireless communication system, for example, various systems such as a mobile phone system and a simple mobile phone system (PHS: Personal Handy Phone System) may be used.

As communication methods, for example, CDMA (Code Division Multiple Access) method, W (Wide band) -CDMA method, TDMA (Time Division Multiple Access) method, FDM, etc.
Various methods such as an A (Frequency Division Multiple Access) method may be used.

  Here, the configuration of the amplification device and the like according to the present invention is not necessarily limited to the above-described configuration, and various configurations may be used. The present invention can also be provided as, for example, a method or method for executing processing according to the present invention, a program for realizing such a method or method, and the like.

  The application field of the present invention is not necessarily limited to the above-described fields, and the present invention can be applied to various fields.

As a conventional distortion compensation amplifying apparatus, a distortion compensation amplifying apparatus using a PD method has been proposed (for example, see Patent Document 1).
JP, 2000-261252, A (page 3-4, Drawing 1) Here, the conventional distortion compensation amplification device by PD method is explained. FIG. 4 is a block diagram showing an example of the configuration of a conventional distortion compensation amplifying apparatus. As shown in FIG. 4, the conventional distortion compensation amplifying apparatus includes directional couplers 1 and 8, a power distributing unit 2, a delay unit 3, a power combining unit 4, a vector adjusting unit 5, a PD unit 6, an amplifier 7, and an input. It comprises a level detection unit 9, a control unit 10, and an output level detection unit 11.

  Next, the operation of the conventional distortion compensation amplification apparatus will be described. First, the input signal is output to the power distribution unit 2 via the directional coupler 1. A part of the input signal is extracted by the directional coupler 1 and output to the input level detection unit 9.

  The input signal is distributed to the delay unit 3 and the PD unit 6 by the power distribution unit 2. The delay unit 3 delays one output of the power distribution unit 2 and outputs it to the power combining unit 4. In addition, the PD unit 6 generates a distortion cancellation signal, which is a signal for canceling distortion generated during amplification, from the other output of the power distribution unit 2 according to control from the control unit 10, and outputs it to the power combining unit 4.

  The power combiner 4 combines the output of the delay unit 3 and the distortion cancellation signal and outputs the combined signal to the amplifier 7 as a combined signal. The amplifier 7 amplifies the combined signal and outputs the amplified signal to the directional coupler 8 as an amplified signal. Here, the distortion generated during amplification and the distortion cancellation signal are canceled out. The amplified signal is output to the outside via the directional coupler 8. A part of the amplified signal is extracted by the directional coupler 8 and output to the output level detector 11. Note that an isolator (ISO) 12 is provided on the output side of the directional coupler 8 to prevent the reflected wave from returning to the amplifier side.

  The input level detection unit 9 detects the power level of the input signal and outputs it to the control unit 10 as an input level. The output level detection unit 11 detects the power level of the amplified signal and outputs it to the control unit 10 as an output level. The control unit 10 extracts the distortion level by comparing the input level and the output level, and controls the PD unit 6 and the vector adjuster 5 so as to reduce the distortion level. The PD unit 6 is composed of individual devices. Devices may be provided in parallel or in series. Further, a combination of series and parallel may be used.

  As described above, the distortion generated during amplification is compensated for by the distortion cancellation signal generated by the PD unit 6.

  However, in the conventional distortion compensation amplification apparatus described above, each device of the PD section has a characteristic change depending on the temperature. Therefore, when there is a change in the ambient temperature, a drastic decrease in the distortion compensation amount due to the temperature is seen. There may be unstable distortion compensation.

  The present invention has been made to solve the above-described problems, and provides a distortion compensation amplifying apparatus that enables stable distortion compensation corresponding to a change in ambient temperature.

  In order to solve the above-described problem, a distortion compensation amplification apparatus according to the present invention generates an input level detection unit that detects an input level from an input signal, and a distortion cancellation signal that cancels distortion generated during amplification from the input signal. A distortion generation unit, a distortion cancellation signal synthesis unit that synthesizes the input signal and the distortion cancellation signal, an amplification unit that amplifies the output of the distortion cancellation signal synthesis unit, and an output that detects an output level from the output of the amplification unit Bias control of the strain generation unit is performed according to the level detection unit, the temperature detection unit for detecting the ambient temperature, the input level detected by the input level detector, and the temperature level detected by the temperature detection unit It is characterized by.

  The distortion compensation amplifying apparatus includes a bias parameter table corresponding to an ambient temperature and an input signal level, calculates an appropriate parameter value, and performs bias control.

  According to the present invention, optimum bias control is always possible regardless of the ambient temperature, so that stable distortion compensation can be provided at high speed regardless of the ambient temperature change.

The distortion compensation amplifying apparatus according to the present invention can always perform optimum bias control regardless of the ambient temperature even if the ambient temperature changes suddenly. It is about. Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a block diagram illustrating an example of a configuration of a distortion compensation amplifying apparatus according to the first embodiment. 1, the same reference numerals as those in FIG. 4 denote the same or corresponding parts as those in FIG. 4, and the description thereof is omitted here. In this embodiment, a control unit 101 is provided instead of the control unit 10, and a temperature detection unit 102 that detects the ambient temperature is further provided. The distortion canceling signal combining unit in the present embodiment is the power distributing unit 2, the delay unit 3, the power combining unit 4, the vector adjuster 5, and the PD unit 6.

Hereinafter, the operation of the distortion compensation amplifying apparatus in the present embodiment will be described.
The control unit 101 reads the value detected by the input level detection unit 9, and further reads the detected value of the ambient temperature detected by the temperature detection unit. Here, the temperature detection unit detects the ambient temperature. However, the temperature detection unit is not limited to this. For example, temperature detection near the amplification unit may be performed.

The value detected by the input level detection unit and the value detected by the temperature detection unit are compared by the table of each device. The table of each device will be described with reference to FIG. In FIG. 2, the vertical axis represents the input level, and the detected value is expressed as “I1, I2”, for example. The horizontal axis is the temperature level and is expressed as, for example, “T1 to T5”. A to J are bias control values for the PD section.
For example, when the input level is 11 and the temperature level is T2, the value B is calculated, and the control unit 101 outputs a bias control value to the PD unit to perform bias control. When the input level is I2 and the temperature level is T3, a value of H is calculated, and the control unit 101 outputs a bias control value to the PD unit to perform bias control.

  Here, I1, I2, and T1 to T5 are set, but this does not indicate a single value but indicates a range thereof. For example, I1 which is an input level sets a range of 10 to 20, and enters I1 when the input level detection unit detects a value of 15. Furthermore, in the case of T2 which is a temperature level, for example, a range of 0 to 10 is set, and when the value of 5 is detected by the temperature detection unit, T2 is entered.

Next, the operation of this embodiment will be described with reference to FIG.
In S2, the temperature detector 102 detects the temperature level. In step S3, the input level detector 9 detects the input level. In S4, it is confirmed whether or not the detected temperature value and the input level have changed. If not, the process returns to S2, and temperature level detection and input level detection are performed. If any of the detected values is different, compare the temperature level detected in S5 with the input level using the table in Fig. 2, and select the optimum value according to the detected ambient temperature and input level. Is calculated. In S6, bias control of each device is performed using the optimum value calculated in S4.

  Although the temperature level is detected in S1 and the input level is further detected in S2, the order is not limited to this order. The input level may be detected first, and then the temperature level may be detected. Further, temperature level detection and input level detection may be performed simultaneously.

  As described above, the distortion compensation amplifying apparatus has a bias parameter table according to the ambient temperature and the input signal level, sets an appropriate parameter value, and performs bias control regardless of the ambient temperature. Since optimum bias control is always possible, it is possible to provide stable distortion compensation at high speed regardless of ambient temperature changes.

  In the present embodiment, the vector adjuster 5 is provided at the front stage of the PD unit 6, but the present invention is not limited to this, and the vector adjuster 5 may be provided at the rear stage of the PD unit. Furthermore, the delay unit 3 only needs to be capable of delaying a signal, and a delay line or a delay filter can be used.

  In this embodiment, the bias control value is calculated based on the input level and the temperature level. However, the present invention is not limited to this. For example, an appropriate bias control value may be calculated according to the output level instead of the input level. good.

1 is a block diagram illustrating an example of a configuration of a distortion compensation amplification device in Embodiment 1. FIG. 6 is a table for calculating a bias control value in the first embodiment. 6 is a flow for performing bias control in the first embodiment. It is a block diagram which shows an example of a structure of the conventional distortion compensation amplifier.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,8 ... Directional coupler, 2 ... Power distribution part, 3 ... Delay part, 4 ... Power combining part, 5 ... Vector adjustment part, 6 ... PD part, 7 ... Amplification part, 9 ... Input level detection part, 10 DESCRIPTION OF SYMBOLS 101 ... Control part 11 ... Output level detection part 12 ... Isolator 102 ... Temperature detection part

Claims (1)

A distortion compensation amplifying apparatus that compensates for distortion generated during amplification, wherein an input level detection unit detects an input level from an input signal, and distortion generation that generates a distortion cancellation signal that cancels the distortion generated during amplification from the input signal A distortion cancellation signal synthesis unit that synthesizes the input signal and the distortion cancellation signal, an amplification unit that amplifies the output of the distortion cancellation signal synthesis unit, a temperature detection unit that detects an ambient temperature, and the input level detection A distortion compensation amplifying apparatus that performs bias control of a distortion generation unit according to an input level detected by a detector and a temperature level detected by the temperature detection unit.

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