JPH0888518A - Distortion compensation method and distortion compensation amplifier - Google Patents

Abstract

PURPOSE: To obtain a distortion compensation method and a distortion compensation amplifier by which appropriate distortion compensation can be performed even in the sudden change of operating environment. CONSTITUTION: The optimum vector quantity of vector adjusters 2, 7 can be found by the optimization processing of a CPU 19, and simultaneously, they are stored in a RAM 22 by relating to temperature and the level of an input signal at that time. When fluctuation occurs in the temperature or the level of the input signal, the optimum vector quantity is read out when the optimum vector quantity corresponding to fluctuated temperature or level of the input signal is stored in the RAM 22, and the vector quantity of the vector adjusters 2. 7 are controlled so as to be the optimum vector quantity read out of the RAM 22 by the CPU 19. In this way, the distortion compensation can be performed with superior responsiveness and appropriately for the level fluctuation of the temperature and the input signal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a distortion compensating amplifier used in a base station common amplifier or a relay amplifier in a car telephone system, and particularly, to improve a method of optimizing a distortion compensation amount. The present invention relates to a distortion compensation control method and a distortion compensation amplification device.

[0002]

2. Description of the Related Art A distortion compensating amplifier is used, for example, in a base station of an automobile telephone system to remove distortion of a radio wave transmitted to a mobile station and amplify its power. FIG. 4 shows an example of a circuit of a conventional distortion compensation amplification device, and this conventional device will be described below with reference to FIG.

This distortion compensating / amplifying device has a circuit configuration using an automatically adjusting feedforward as a non-linear distortion compensating circuit for simultaneously amplifying radio waves of a plurality of frequencies. That is, the distortion compensation amplification device is roughly divided into the distortion detection unit 25, the distortion removal unit 26, and the control unit 27.

The distortion detector 25 is a directional coupler 1 for splitting an input signal (see the waveform diagram a in FIG. 4) into two signals.
A vector adjuster 2 for performing vector adjustment on one of the signals branched by the directional coupler 1, a main amplifier 3 for power-amplifying the signal input via the vector adjuster 2, and a direction It has a delay line 5 for delaying the other signal branched by the directional coupler 1, and a directional coupler 4 to which the signal from the main amplifier 3 and the signal from the delay line 5 are applied. It is a thing.

In the distortion detector 25, the main amplifier 3
In order to compensate for the intermodulation distortion generated at 1, the vector amount of the input signal is adjusted by the vector adjuster 2 before being input to the main amplifier 3, while the inverse of the other output from the directional coupler 1 is adjusted. The timing of the phase signal depends on the vector adjuster 2
Also, it is delayed by the delay line 5 so as to coincide with the timing of one signal that has passed through the main amplifier 3.

The signal output from the main amplifier 3 (see waveform diagram b in FIG. 4) and the signal passing through the delay line 5 (see waveform diagram f in FIG. 4) are input to the directional coupler 4. Thus, a signal having only a distortion component and a signal from the main amplifier 3 containing distortion are branched into two and taken out. The distortion detector 25 is provided with a pilot signal generator 11 so that the pilot signal is added to the directional coupler 4 together with the output signal of the main amplifier 3.

The distortion removing section 26 is a vector adjuster 7 for performing vector adjustment on the distortion component extracted from the directional coupler 4, an auxiliary amplifier 8 for amplifying an output signal of the vector adjuster 7, and a direction. A delay line 6 for delaying the signal passed through the main amplifier 3 extracted from the directional coupler 4 so as to match the timing with the signal passed through the vector adjuster 7 and the auxiliary amplifier 8; And a container 9.

In the directional coupler 9, the signal from the main amplifier 3 input through the delay line 6 and the anti-phase signal from the vector adjuster 7 and the auxiliary amplifier 8 (see the waveform diagram d in FIG. 4).
Is added and the distortion component is canceled out (see the waveform diagram c in FIG. 4).

The control unit 27 is for adjusting the vectors of the vector adjusters 2 and 7, and includes a CPU 19 for executing optimization control, a decoding circuit 20, a ROM 21 in which programs and the like are stored, and a temporary data. A RAM 22 used for storage and the like, and two analog / digital converters (abbreviated as “A / D” in FIG.
/ D converter ") 15, 16 and two digital-analog converters (abbreviated as" D / A "in FIG. 4 and hereinafter referred to as" D / A converter ") 17, 18 A main component is a pilot signal receiver 13 for detecting a pilot signal included in the output signal of the directional coupler 9, and a detector 12 for detecting a signal from the directional coupler 4. It is provided.

Based on the output signal of the detector 12 input via the A / D converter 15 and the output signal of the pilot signal receiver 13 input via the A / D converter 16, The CPU 19 performs an optimization process for determining the optimum vector amount of the vector adjusters 2 and 7, that is, the amplitude and the phase. When a control signal is output from the CPU 19 to control the vector adjusters 2 and 7 to the amplitude and phase determined by this optimization processing, the control signal is decoded by the decoding circuit 20 and the decoded signal is D / A converted. By being converted into an analog signal by the converters 17 and 18 and applied to the vector adjusters 2 and 7, the vector adjusters 2 and 7 are set to the amplitude and phase obtained by the optimization processing in the CPU 19. .

[0011]

However, in the optimization processing executed in the above-mentioned conventional apparatus, especially when the main amplifier 3 adopts the class AB amplifier circuit, the ambient temperature or the input signal level of this apparatus is increased. When there is a sudden change, the fluctuation is large, and it takes time until the amplitude and phase amount of the vector adjusters 2 and 7 are set to appropriate values.
There is a problem that the distortion may become spurious.

The present invention has been made in view of the above circumstances, and a distortion compensation control method and a distortion compensation control method capable of performing a rapid and appropriate distortion compensation without using a special high-speed component even when the operating environment changes suddenly. An object of the present invention is to provide a distortion compensation amplification device.

[0013]

According to a first aspect of the present invention, there is provided a distortion compensation control method having an amplifying means for power-amplifying an input signal, and a vector amount of the input signal depending on a control signal externally input. Distortion detecting means for detecting the distortion component contained in the output signal of the amplifying means from the signal passing through the amplifying means and the signal bypassing the amplifying means while adjusting the distortion, and the distortion detected by the distortion detecting means. Distortion removing means for removing the distortion component included in the output signal by adding the distortion component to the output signal of the amplifying means while adjusting the vector amount of the component according to the externally input control signal, Distortion compensation increasing means comprising: a control means for determining an optimum vector amount in the distortion detecting means and the distortion removing means and outputting a control signal to the distortion detecting means and the distortion removing means. A distortion compensation control method in an apparatus, wherein each time the optimum vector amount is determined by the control means, the optimum vector amount is stored in association with the ambient temperature and the signal level of the input signal, and the ambient temperature or When the input signal fluctuates, if the optimum vector amount corresponding to the fluctuating ambient temperature and the input signal exists among the stored optimum vector amounts, the optimum vector amount is set to the strain detecting means and This is the vector amount in the distortion removing means.

The distortion compensating and amplifying device according to a second aspect of the present invention has an amplifying means for power-amplifying an input signal, and
The distortion component contained in the output signal of the amplifying means is detected from the signal that has passed through the amplifying means and the signal that has bypassed the amplifying means while adjusting the vector amount of the input signal according to the control signal input from the outside. By adding the distortion component to the output signal of the amplifying means while adjusting the vector amount of the distortion component detected by the distortion detecting means according to a control signal input from the outside. Distortion removing means for removing a distortion component included in an output signal, control for determining an optimum vector amount in the distortion detecting means and the distortion removing means, and outputting a control signal to the distortion detecting means and the distortion removing means Means, level detecting means for detecting the signal level of the input signal, temperature detecting means for detecting the ambient temperature, and each time the optimum vector amount is determined by the control means. Storage means for storing the optimum vector amount in association with the detection data of the level detection means and the temperature detection means, and when the input signal or temperature changes, the storage means stores the signal level or temperature of the input signal after the change. When the corresponding optimum vector quantity is stored, the distortion detecting means and the distortion removing means have priority over the control means so that the vector quantity in the distortion detecting means and the distortion removing means becomes the optimum vector quantity. And a fluctuation control means for outputting a control signal.

In particular, the distortion detecting means adjusts the vector amount for a first directional coupler that divides the input signal into two and one branch signal of the first directional coupler and inputs the vector amount to the amplifying means. The other branch signal of the first vector adjuster and the other branch signal of the first directional coupler so that the other branch signal has the same timing as the signal passed through the first vector adjuster and the amplifying means. A first delay line that gives a delay to the input signal, the output signal of the amplifying means and the signal that has passed through the first delay line, and the distortion component included in the output signal of the amplifying means and the amplifying means. And a second directional coupler that outputs an output signal of the second directional coupler, and the distortion removing means adjusts the vector amount with respect to the distortion component extracted from the second directional coupler. 2 vector adjusters,
The auxiliary amplifier for amplifying the output signal of the second vector adjuster and the output signal of the amplifying means obtained via the second directional coupler are used to output the second vector adjuster and the auxiliary amplifier. A second delay line that gives a delay so as to have the same timing as the passed signal, the output signal of the auxiliary amplifier, and the signal passed through the second delay line are input, and the output signal of the amplification means is output. A device including a third directional coupler that outputs a signal from which a distortion component is removed is preferable.

[0016]

According to the first aspect of the invention, each time the optimum vector amount is obtained, it is stored in association with the ambient temperature at that time and the level of the input signal, and then the ambient temperature or the level of the input signal changes. In the case of occurrence of the above, first, if there is an optimum vector quantity corresponding to the changed ambient temperature or input level among the stored optimum vector quantities, this optimum vector quantity is used. Since it is not necessary to calculate the optimum vector amount for the changed ambient temperature or the level of the input signal, it is possible to immediately cope with the variation of the ambient temperature or the level of the input signal.

In the second and third aspects of the present invention, the optimum vector amount in the strain detecting means and the strain removing means is determined by the control means. On the other hand, the optimum vector amount is the ambient temperature and the level of the input signal. When the ambient temperature or the level of the input signal is changed, the optimum vector amount corresponding to the ambient temperature or the level of the input signal after the change is stored in the storage data of the storage means. In this case, the fluctuation control means, instead of the control means, controls the vector amounts of the strain detection means and the strain removal means to be the optimum vector amounts, so that the control means spends time required to determine the optimum vector amounts. Instead, the vector amount of the strain detection means and the strain removal means is set immediately, and the fluctuation of the ambient temperature and the fluctuation of the level of the input signal are prevented. One in which agility is increased by.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the distortion compensating and amplifying device according to the present invention will be described below with reference to FIGS. Here, FIG. 1 is a configuration diagram of an embodiment of the distortion compensation amplification device according to the present invention, and FIG. 2 is a flowchart showing a procedure for setting adjustment data of a vector adjuster in the distortion compensation amplification device of the present embodiment. FIG. 3 is an explanatory diagram for explaining the storage format of the adjustment data in the RAM used in the distortion compensation amplification device of the present embodiment. The members, arrangements, and the like described below do not limit the present invention and can be variously modified within the scope of the gist of the present invention.

First, an example of the configuration of the distortion compensation amplification device in this embodiment will be described with reference to the configuration shown in FIG. The distortion compensation amplification device of this embodiment is configured by adding the following components to the conventional device described in FIG. 4, and most of the components are the same as those of the conventional device. . Therefore, in the following description, the same components as those of the conventional device will be denoted by the same reference numerals, and detailed description thereof will be omitted.

The distortion compensation amplifying apparatus of this embodiment is provided with an input level detector 30 as a level detecting means for detecting the level of an input signal in the preceding stage of the directional coupler 1, and in the vicinity of the distortion detecting section 25. In addition, a temperature sensor 31 as temperature detecting means for detecting the ambient temperature, and an analog / digital converter for converting the output signals of the input level detector 30 and the temperature sensor 31 into digital signals (see FIG. 1).
Is abbreviated as "A / D" in the following, and is hereinafter referred to as "A / D converter" 32, 33.

The operation of this device can be summarized as follows.
Each time the CPU 19 performs an optimization process for determining the amplitude and phase of the vector adjusters 2 and 7, the input level detector 30 inputs the input level of the input signal to the apparatus and the temperature sensor 31 outputs the temperature of the wireless part. Each level is detected, and the CPU 1 at that time uses the detected input level and temperature level as parameters as described later.
The adjustment data of the vector adjusters 2 and 7 determined by the optimization processing in 9 are stored in the RAM 22 in a tabular form, and thereafter, when the input level and the temperature level at this time are detected again, the vector adjustment is performed from the RAM 22. Bowl 2,7
The adjustment data is read out and the vector adjusters 2 and 7 are immediately adjusted with the adjustment data, thereby compensating for the delay in the processing due to the optimization processing and performing distortion compensation with good responsiveness. .

Next, an optimization process in the CPU 19 for determining adjustment data for setting the amplitude and phase of the vector adjusters 2 and 7 will be described with reference to FIGS. 2 and 3. First, the program is read from the ROM 21 into the CPU 19, and the distortion level is determined (step 100 in FIG. 2). That is, a part of the output of the main amplifier 3 detected by the detector 12 is converted into a digital signal by the A / D converter 15, and the pilot signal level detected by the pilot signal receiver 13 is A / D.
The digital signal converted by the D converter 16 is the CPU
It is taken into 19 and it is judged whether the distortion level is enough to cause spurious. Then, when it is determined that spurious is generated (in the case of NO), it is determined whether or not there is a change in the input level of this device or the temperature level of the wireless unit (step 102 in FIG. 2). If it is determined in step 100 that the distortion level is not a level that causes spurious (YES), the determination process is repeated until NO is determined.

When it is determined that neither the input level of the apparatus nor the temperature level of the wireless unit has changed (in the case of NO)
On the other hand, while proceeding to the processing of step 110 described later, if it is determined that there is any change (in the case of YES), the adjustment data is searched (step 10 in FIG. 2).
4). That is, the RAM 22 in the present embodiment stores the adjustment data of the vector adjusters 2 and 7 as parameters of the input level of this apparatus and the temperature level of the wireless unit, and the input level and the temperature at the time of processing in step 104 are stored. A search is made as to whether or not the adjustment data corresponding to the level is stored in the RAM 22.

Here, the storage format of the adjustment data of the vector adjusters 2 and 7 in the RAM 22 will be described with reference to the example shown in FIG. The table for storing the adjustment data of the vector adjusters 2 and 7 shown in FIG. 3 has a vertical axis as a temperature level and a horizontal axis as an input level. Adjustment data is arranged for each.

Here, the temperature level on the vertical axis is the temperature sensor 3 after being converted into a digital signal by the A / D converter 33.
1 means the output level, and the input level on the horizontal axis also means the output level of the input level detector 30 after being digitalized by the A / D converter 32. Incidentally, the A / D converters 32 and 33 in the present embodiment
Uses an 8-bit output.

In this embodiment, both the vertical axis and the horizontal axis
The output level of the A / D converters 32 and 33 is divided into 20 units, and 13 × 13 pieces of adjustment data can be stored as a whole. For example, in the area indicated by reference numeral a, the adjustment data of the vector adjusters 2 and 7 when the temperature level is 220 to 240 and the input level is also 220 to 240 are stored (see FIG. 3). . In other areas, basically, the condition of the adjustment data stored in the same manner is determined by the relationship between the temperature level and the input level.

The adjustment data for the corresponding temperature level and input level is searched from the table of the adjustment data set in this way, and after the search, the D / A converters 17 and 18 are searched.
The adjustment data is input to the vector adjusters 2 and 7 via the, and the amplitude and phase of the vector adjusters 2 and 7 are set according to the respective input data (step 106 in FIG. 2).

Then, in the state where the vector adjusters 2 and 7 are set according to the adjustment data read from the RAM 22 as described above, it is judged whether or not the distortion level is such that spurious occurs (FIG. 2). If it is determined that the distortion level is not a level causing spurious (YES in step 108), the process returns to step 102 and the series of processes described above is repeated.

On the other hand, when it is determined that the distortion level is a level that causes spurious (NO), the RAM 2
Since it means that the adjustment data of the vector adjusters 2 and 7 read out from No. 2 is not optimum, C
The PU 19 performs an optimization process for determining the optimum adjustment data for the vector adjusters 2 and 7 (step 110 and step 112 in FIG. 2).
That is, the optimization process is performed until the optimum values of the amplitude and phase of the vector adjusters 2 and 7 are obtained (step 112 in FIG. 2).

When it is judged that the optimization is completed (see FIG.
If YES in step 112), the adjustment data is written (step 114 in FIG. 2). That is, the adjustment data of the vector adjusters 2 and 7 which are determined to be optimum are written in a predetermined portion of the RAM 22 using the corresponding temperature level and input level as parameters as described above with reference to FIG. At this time, if the adjustment data is already written in the portion corresponding to the corresponding temperature level and input level, new optimum data will be overwritten on the already written adjustment data. After the writing of the adjustment data, the process returns to the previous step 100 and the series of processes described above is repeated again.

Here, the operation of the present apparatus will be briefly described again. If the amplitude and phase of the vector adjuster 2 are CPU 19,
The input signal is input to the distortion detecting section 25 as the distortion detecting means set by the optimization method of (1), and the distortion component is detected. In the distortion removing unit 26 as the distortion removing unit, the amplitude and phase of the vector adjuster 7 are set by the optimization method of the CPU 19 as well, so that the distortion component detected by the distortion detecting unit 25 and the main component as the amplifying unit. A signal from which the distortion component has been removed can be obtained by adding the outputs of the amplifier 3 in opposite phases and at the same level.

On the other hand, the adjustment data of the vector adjusters 2 and 7 obtained by the CPU 19 by the optimization method are the input level of the input signal detected by the input level detector 30 and the temperature sensor when they are obtained as the optimum data. R in association with the temperature level detected by 31 (see FIG. 3)
It is stored in the AM 22. Then, when the input level or the temperature level suddenly changes, the adjustment data corresponding to the changed input level or the temperature level is read from the RAM 22, and the amplitude and phase of the vector adjusters 2 and 7 are based on the adjustment data. Even if there is a sudden change in the input level or the temperature level that has been set, distortion compensation can be performed quickly and appropriately, and spurious components can be prevented from being included in the output signal.

In the above-described embodiment, the CPU 19 and the RAM 22 and the storage means are realized by executing the steps 112 and 114 of FIG.
Further, the fluctuation control means is realized by executing steps 102, 104 and 106 in FIG. Further, the directional coupler 1 is the first directional coupler according to claim 3, the directional coupler 2 is the second directional coupler according to claim 3, and the directional coupler 9 is the claim. 3 corresponds to the third directional coupler described in 3.

[0034]

As described above, according to the first and second aspects of the invention, the optimum vector amount is stored in association with the ambient temperature and the level of the input signal, and the optimum vector amount is stored as the ambient temperature or the level of the input signal. If there is a fluctuation and the optimum vector quantity corresponding to the changed ambient temperature or the level of the input signal is present in the stored data, the optimum vector quantity can be determined again by using this stored data. Since the time corresponding to the time required can be saved, it is possible to instantly optimize the variation of the ambient temperature and the variation of the level of the input signal.

In particular, in the apparatus according to the second and third aspects of the present invention, in addition to the above effects, the optimum vector amount is immediately set with respect to the variation as described above, and therefore, unlike the prior art, A class AB amplifier circuit can be adopted in the amplifier means. In addition, it is possible to provide a distortion compensation amplification device that can quickly and appropriately perform distortion compensation without using a high-speed component.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment of a distortion compensation amplification device according to the present invention.

FIG. 2 is a flowchart showing a procedure for setting adjustment data of a vector adjuster in the distortion compensation amplification device of this embodiment.

FIG. 3 is a RAM used in the distortion compensation amplification device of the present embodiment.
FIG. 5 is an explanatory diagram for explaining a storage format of adjustment data to the.

FIG. 4 is a configuration diagram showing a configuration example of a conventional distortion compensation amplification device.

[Explanation of symbols]

1, 4, 9 ... Directional coupler, 2, 7 ... Vector adjuster, 3 ... Main amplifier, 5, 6 ... Delay line, 8 ... Auxiliary amplifier, 11 ... Pilot signal generator, 12 ... Detector,
13 ... Pilot signal receiver, 15, 16, 32,
33 ... A / D converter, 17, 18 ... D / A converter,
19 ... CPU, 20 ... Decode circuit, 21 ... ROM,
22 ... RAM, 25 ... Distortion detection part, 26 ... Distortion removal part, 27 ... Control part, 30 ... Input level detector, 3
1… Temperature sensor

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Eiji Hirota 3-14-20 Higashi-Nakano, Nakano-ku, Tokyo Kokusai Electric Inc.

Claims (3)

[Claims] 1. An amplification means for amplifying the power of an input signal is provided, and a signal passing through the amplification means and the amplification means are bypassed while adjusting a vector amount of the input signal according to a control signal externally input. And a distortion detecting means for detecting a distortion component included in the output signal of the amplifying means from the signal, and adjusting the vector amount of the distortion component detected by the distortion detecting means according to a control signal input from the outside. Distortion removing means for removing the distortion component contained in the output signal by adding the distortion component to the output signal of the amplifying means, and determining the optimum vector amount in the distortion detecting means and the distortion removing means, What is claimed is: 1. A distortion compensation control method in a distortion compensation amplification apparatus, comprising: distortion detection means and control means for outputting a control signal to the distortion removal means. Each time the optimum vector amount is determined, the optimum vector amount is stored in association with the ambient temperature and the signal level of the input signal, and is stored when the ambient temperature or the input signal fluctuates. When there is an optimum vector quantity corresponding to the changed ambient temperature and the input signal among the optimum vector quantities, the optimum vector quantity is used as the vector quantity in the distortion detection means and the distortion removal means. Distortion compensation control method. 2. An amplification means for amplifying the power of an input signal is provided, and a signal passing through the amplification means and the amplification means are bypassed while adjusting a vector amount of the input signal according to a control signal externally input. And a distortion detecting means for detecting a distortion component included in the output signal of the amplifying means from the signal, and adjusting the vector amount of the distortion component detected by the distortion detecting means according to a control signal input from the outside. Distortion removing means for removing the distortion component contained in the output signal by adding the distortion component to the output signal of the amplifying means, and determining the optimum vector amount in the distortion detecting means and the distortion removing means, Control means for outputting a control signal to the strain detecting means and the strain removing means, level detecting means for detecting the signal level of the input signal, and temperature detecting means for detecting the ambient temperature. And a storage means for storing the optimum vector amount in association with the detection data of the level detecting means and the temperature detecting means, and an input signal or temperature fluctuates each time the optimum vector amount is determined by the control means. At this time, when the optimum vector amount corresponding to the signal level or the temperature of the input signal after the change is stored in the storage unit, the vector amount in the distortion detection unit and the distortion removal unit is prioritized over the control unit. A distortion compensation amplification apparatus comprising: a fluctuation control unit that outputs a control signal to the distortion detection unit and the distortion removal unit so that the optimum vector amount is obtained. 3. The distortion detecting means adjusts a vector amount for a first directional coupler that divides an input signal into two and one branch signal of the first directional coupler and inputs the vector quantity to an amplifying means. To the other branch signal so that the other branch signal of the first vector adjuster and the other branch signal of the first directional coupler have the same timing as the signal passed through the first vector adjuster and the amplifying means. A first delay line that gives a delay to the input, the output signal of the amplifying means, and the signal that has passed through the first delay line are input, and the distortion component included in the output signal of the amplifying means and the amplifying means A second directional coupler that outputs an output signal, and the distortion removing means adjusts the vector amount for the distortion component extracted from the second directional coupler. Vector adjuster, and the second
An auxiliary amplifier for amplifying the output signal of the vector regulator of
A second delay is provided so that the output signal of the amplification means obtained via the second directional coupler has the same timing as the signal passed through the second vector adjuster and the auxiliary amplifier. A third directional coupler that receives a delay line, an output signal of the auxiliary amplifier, and a signal that has passed through the second delay line, and outputs a signal in which a distortion component is removed from the output signal of the amplifying means. 3. The distortion compensation amplification device according to claim 2, further comprising: