JP2004040219A - Transmission output control apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem that miscontrol is caused by the effect of large variation data when an output control signal is produced from averaged data including data denoting temporary large output variations such as a noise and instantaneous voltage variations or the like and is used for control. <P>SOLUTION: A CPU 25 calculates an average of output data from an analog / digital converter 24 in response to an output of a power amplifier section 21 and also calculates the variance of the data, stops output control operations using the calculated averaged value data when the variance exceeds a preset threshold value of the variance stored in a memory 26, and calculates averaged data and a variance on the basis of new output data to perform control. Further, the CPU 25 changes the number of data to be averaged depending on the magnitude of the variance into a prescribed number stored in the memory 26 and performs the output control. <P>COPYRIGHT: (C)2004,JPO

Description

を算出すると共にそのデータの分散Ｂ_１ｎを算出する。
ここに、Ｎ個のデータの平均値
【数２】

及び分散Ｂ_Ｎは、それぞれ
【式１】

【式２】

で計算される。
【００１１】
前記メモリ２６には、予め電力増幅部２１が変調波を送信する時に取りうる最大の分散の値（以下、分散のしきい値という）Ｂ_ｍａｘをシステム設定時の実験等の結果に基づいて設定して記憶させておく。前記ＣＰＵ２５で計算した分散の値Ｂ_１ｎが前記しきい値Ｂ_ｍａｘより大きいときは、データの中に雑音等による異常なデータが混入していると判断されるので、次のように処理する。
平均の算出法が時間平均の場合は、このデータの平均値による送信出力制御は中止して、次のｎ個のデータで、同様に平均値
【数３】

と分散値Ｂ_２ｎを計算し、また、平均の算出法が移動平均の場合は、２から（ｎ＋１）番目のｎ個のデータで平均値「数３」と分散値Ｂ_２ｎを計算する。該Ｂ_２ｎがしきい値Ｂ_ｍａｘ以下の場合には、目標送信レベルと平均値「数３」との差異を検出し、その差異に対応したＰＩＮダイオードアッテネータ１１のバイアス電圧補正値を前記メモリ２６から選択して出力する。
前記バイアス電圧補正値は、Ｄ／Ａ変換器２７でアナログ信号に変換され、バッファアンプ２８を介してＰＩＮダイオードアッテネータ１１に印加される。
これによって、前記ＰＩＮダイオードアッテネータ１１の減衰量が所定の値となり、周波数変換部１２から電力増幅部２１へ出力される信号レベルが調整され、前記電力増幅部２１の出力は、高い精度で目標送信電力レベルに保たれることになる。
【００１２】
上述のように、分散のしきい値Ｂ_ｍａｘより計算された分散値Ｂ_ｎが大となることが連続した場合は、次のように平均化する出力データの数を調整することによって算出する平均値のもっともらしさの度合いを高めることが出来る。
即ち、しきい値Ｂ_ｍａｘ＜計算値Ｂ_ｎとなることが所定のｐ回連続した場合、あるいは過去所定のｑ回のうち所定のｒ回発生した場合は、平均化するデータ数ｎを増やしてｍ（ｎ＜ｍ）個とする。そして、その後に、しきい値Ｂ_ｍａｘより小さいい値のＢ_ｍａｘ’　に対してＢ_ｍａｘ’　＞Ｂｎとなることがｐ’　回連続した場合、あるいは過去所定のｑ’　回のうち所定のｒ’　回発生した場合は、平均化するデータ数を元のｎ個に戻す。
上記分散のしきい値Ｂ_ｍａｘ、Ｂ_ｍａｘ’、平均化するデータ数ｎ、ｍ、回数ｐ、ｑ、ｒ等はシステム設定時に、予めメモリ２６に記憶させておくものとする。
上述のように、分散の大きさに応じて平均化するデータの個数を加減することによって、算出される平均値がより信頼性の高い値となる。
【００１３】
【発明の効果】
以上説明したように、本発明によれば、演算処理装置で送信電力増幅部の出力の平均化レベルと目標の出力レベルとを比較して送信電力増幅部出力をする送信出力制御装置において、出力レベルの平均値と共に出力レベルの分散の値を算出し、算出した分散値が予め設定した分散値（しきい値）を超える場合は、その平均値レベルによる送信出力制御動作を行わないようにして、新たなデータで送信制御を行うようにし、さらに、算出した分散の大きさに応じて平均値化するデータの数を変化させるようにしたので、平均値の信頼度をより高くすることができる。
したがって、雑音や瞬時電圧変動等の一時的な大きな出力変動を示すデータが送信出力の平均化データに及ぼす影響を除去して、精度の高い送信出力制御手段を提供することができる。
【図面の簡単な説明】
【図１】本発明に係わるディジタル無線通信システムの送信電力増幅装置の、主として送信出力制御系統の実施の一形態例を示す構成概要図
【図２】従来のディジタル無線通信システムの送信電力増幅装置の、主として送信電力制御系統の一例を示す構成概要図。
【図３】バースト的に送信される出力信号と、その一部を拡大した波形の一例を示す図。
【図４】図３の出力信号の他の一部を拡大した波形例を示す図。
【符号の説明】
１・・送信周波数変換装置、　　　　　　　　　　　　　　２・・　送信電力増幅装置、
１１・・ＰＩＮダイオードアッテネータ、　　１２・・周波数変換部、
２１・・電力増幅部、　　　　２２・・方向性結合器、　　　　２３・・検波器、
２４・・Ａ／Ｄ変換器、　　　　　　　　　　　　　　　　２５、２５ａ・・ＣＰＵ、
２６、２６ａ・・メモリ、２７・・Ｄ／Ａ変換器、２８・・バッファアンプ[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a transmission power control device for a digital wireless communication device, and more particularly to a transmission power control device that controls transmission power with high accuracy by an arithmetic device such as a CPU.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in a digital wireless communication system, transmission power fluctuation due to burst transmission in a TDMA (Time Division Multiple Access) system, a packet transmission system, or the like, or transmission power fluctuation in a communication system with a variable carrier frequency or data rate, and a change in device temperature In general, the following method is used as means for performing transmission output control with good tracking performance to control the output level of transmission power within a predetermined range.
That is, the output level of the transmission power amplification unit detected by the power detection unit of the communication system is digitized and read into an arithmetic unit (hereinafter, referred to as a CPU). In the CPU, a control signal according to the variation of the transmission power is transmitted to a frequency converter in front of the power amplifier, and the output of the frequency converter to the power amplifier is changed by changing the attenuation of a variable attenuator in the frequency converter. Increase or decrease the power. Thereby, the output level of the transmission power amplifier is controlled to be within a predetermined range.
[0003]
FIG. 2 is a schematic configuration diagram mainly showing an example of a transmission output control system of a transmission power amplifier of a conventional digital wireless communication system.
As shown in the figure, the transmission output control system of the present amplification device includes a transmission frequency conversion device 1 including a PIN diode attenuator 11 and a frequency conversion unit 12, a power amplification unit 21, a directional coupler 22, and a detector. 23, an A / D converter 24, a CPU 25a, a memory 26a, a D / A converter 27, and a transmission power amplifier 2 including a buffer amplifier 28.
In the figure, a transmission signal of an intermediate frequency input to a transmission frequency conversion device 1 is level-adjusted in a PIN diode attenuator 11 whose attenuation is controlled by a bias voltage output from a transmission power amplification device 2, and transmitted to a frequency conversion unit 12. input. In the frequency converter 12, the transmission signal of the intermediate frequency is converted to a transmission frequency and output to the transmission power amplifier 2. The transmission signal input to the power amplification unit 21 of the transmission power amplification device 2 is amplified to a predetermined power and output through the directional coupler 22.
[0004]
On the other hand, a part of the transmission power branched by the directional coupler 22 is converted into a DC signal by the detector 23. Thereby, the fluctuation of the transmission power is detected as the fluctuation of the DC signal. The DC output signal of the detector 23 is converted into a digital DC signal in the A / D converter 24 and read into the CPU 25a.
The CPU 25a reads the DC output voltage level of the A / D converter 24 corresponding to the transmission power, detects a difference from an initially set target transmission power level stored in the memory 26a in advance, and detects the difference. The bias output correction value of the PIN diode attenuator 11 is selected and output from the memory 26a in order to make the transmission output of the power amplification unit 21 corresponding to the predetermined value close to a predetermined target value.
The bias voltage correction value is converted into an analog signal by the D / A converter 27 and applied to the PIN diode attenuator 11 of the transmission frequency conversion device 1 via the buffer amplifier 28. The attenuation of the PIN diode attenuator 11 becomes a predetermined value according to the applied bias correction value, and adjusts the transmission signal level input to the frequency conversion unit 12. Thus, the signal level input from the transmission frequency converter 1 to the transmission power amplifier 2 is adjusted, and the output of the power amplifier 21 is maintained at the target transmission power level.
[0005]
FIG. 3 is a diagram illustrating an example of an output signal transmitted in a burst and a waveform obtained by enlarging a part of the output signal. A solid line indicates an output waveform when transmission output control is not performed, and a dotted line indicates a target transmission power. Indicates a level.
As described above, when the individual data of the output of the A / D converter 25a corresponding to the output of the power amplifying unit 21 is compared with the target power level, and the difference is read to perform transmission output control, the transmission output becomes modulated wave. Therefore, the output control is performed following the level fluctuations, so that the output level fluctuations may be further increased. Explaining with the enlarged waveform of FIG. 3, since the output level of each of the output levels A, B, C, D,..., For example, is higher than the target level, the output is controlled so as to lower the output. The value will be lower than the indicated level.
Therefore, it is common practice to take the average value of a plurality of continuous data of the output level of the A / D converter 25a corresponding to the transmission power and compare the average value with the target transmission power level. There are two ways to take the value, time average and moving average.
[0006]
The time averaging method calculates an average value of continuous n output data from the output of the A / D converter 25a, reads a difference between the target transmission power level and the average value, and outputs a bias correction voltage. Output control is performed at the time of the n-th data. Next, a new output control is performed at the 2n-th time point by averaging the output data from the (n + 1) -th to 2n. Hereinafter, similarly, power control is performed at the time of an integral multiple of n. FIG. 3 shows a case where the average value of the levels at three points is obtained. First, the average value c of the levels at points A, B, and C is calculated, and the output control is performed at point C. Next, an average value f of the levels at points D, E, and F is calculated, and output control is performed at point F. Hereinafter, the same control is performed.
FIG. 4 is a diagram showing a waveform example in which another part of the output signal of FIG. 3 is enlarged.
In the moving average method, an average of n output data is taken out of the continuous A / D converter 25a output, output control is performed at the n-th time point, and then 2 to n + 1-th time points at the (n + 1) -th time point. Output control is performed by taking the average of the data up to. Similarly, output control is continuously performed by averaging n data at the time when the next output data is obtained. FIG. 4 shows a case where the average value of the levels at four points is obtained. First, the average value d of the levels at points A, B, C, and D is calculated, and the output control is performed at point D. Next, an average value e of the levels at points B, C, D, and E is calculated, and output control is performed at point E. Hereinafter, the same control is performed.
By averaging the data as described above, it is possible to prevent erroneous control caused by performing output control following the individual data.
[0007]
[Problems to be solved by the invention]
However, as described above, in the output control method for comparing the target transmission power level with the average value and correcting the difference, the output data of the A / D converter 25a is generated due to noise or instantaneous fluctuation of voltage. When a large fluctuation is detected, for example, when the level of D is detected as D 'in FIG. 3, in the time average method, the transmission output of the control result has a magnitude of (D'-D) / 3. If a correction error occurs and the level of D is detected as D 'in the moving average of FIG. 4, a correction error having a magnitude of (D'-D) / 4 is calculated as a moving average including D'. There is a problem that it occurs over the four control operations performed.
The present invention has been made in order to solve the above-described problem, and eliminates the influence of data indicating a large temporary output fluctuation due to noise or the like on the averaged data, thereby providing a highly accurate transmission output control means. The purpose is to provide.
[0008]
[Means for Solving the Problems]
In order to solve the above problem, in the wireless communication system according to the first aspect, an average value of a predetermined number of continuous output level data of a transmission power amplifying device having a transmission signal level adjusting unit is calculated, and the average value is calculated. A signal for comparing the input power level with a preset target transmission output level, detecting the difference, and correcting the input level so that the output level of the transmission power amplifier becomes the target transmission output level according to the detected difference. And a transmission output control device of a digital wireless communication system having an arithmetic processing device for sending the signal to the input level adjusting means.
In the arithmetic processing device, the variance value of the output level data is calculated simultaneously with the calculation of the average value of the output level data of the transmission power amplifying device, and when the magnitude of the variance exceeds a preset threshold value, The transmission output control based on the average value is stopped, and the average value of the new output level data is obtained again.
In the wireless communication system according to the second aspect, an average value of the output level data of the transmission power amplifying device is calculated by a time average.
In the wireless communication system according to a third aspect, an average value of the output level data of the transmission power amplifying device is calculated by a moving average.
In the wireless communication system according to a fourth aspect, in the wireless communication system according to the first to third aspects, the number of output level data for calculating an average value is changed according to the calculated variance. I do.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail based on an embodiment shown in the drawings.
FIG. 1 is a schematic configuration diagram mainly showing an embodiment of a transmission output control system of a transmission power amplifying apparatus of a digital wireless communication system according to the present invention.
As shown in the figure, the transmission output control system of the present amplification device includes a transmission frequency conversion device 1 including a PIN diode attenuator 11 and a frequency conversion unit 12, a power amplification unit 21, a directional coupler 22, and a detector 23. , An A / D converter 24, a CPU 25, a memory 26, a D / A converter 27, and a buffer amplifier 28.
The functional operation of each component of the transmission output control system of the transmission power amplifying device according to the present invention is the same as the functional operation of each component in FIG. 2 except for the CPU 25 and the memory 26. Detailed description of the operation is omitted.
[0010]
In FIG. 1, a transmission signal whose level is adjusted by a PIN diode attenuator 11 and converted into a transmission frequency by a frequency conversion unit 12 is amplified to a predetermined power by a power amplification unit 21 and output via a directional coupler 22. . On the other hand, a part of the transmission power branched by the directional coupler 22 is converted into a DC signal by the detector 23, converted into a digital DC signal by the A / D converter 24, and read into the CPU 25.
In the CPU 25, the DC output voltage level of the A / D converter 24 corresponding to the transmission power is read in a preset number (n) stored in the memory 25, and the average value thereof is expressed as follows.

_Is calculated, and the variance B _1n of the data is calculated.
Here, the average value of N data

And the variance _BN are represented by

[Equation 2]

Is calculated by
[0011]
In the memory 26, a maximum dispersion value (hereinafter, referred to as a dispersion threshold) B _max that can be taken when the power amplifying unit 21 transmits the modulated wave is set in advance based on a result of an experiment or the like at the time of setting the system. And memorize it. When the variance value B _1n calculated by the CPU 25 is larger than the threshold value B _max, it is determined that abnormal data due to noise or the like is mixed in the data, and the processing is performed as follows.
When the average calculation method is the time average, the transmission output control based on the average value of this data is stopped, and the average value is similarly calculated for the next n data.

And the variance value B _2n , and when the average is calculated by the moving average, the average value “Equation 3” and the variance value B _2n are calculated using the (n + 1) -th n pieces of data. If the B _2n is equal to or less than the threshold B _max is said to detect the difference between the average value and the target transmission level "number 3", the bias voltage correction value of the PIN diode attenuator 11 corresponding to the difference memory 26 Select from and output.
The bias voltage correction value is converted into an analog signal by the D / A converter 27 and applied to the PIN diode attenuator 11 via the buffer amplifier 28.
As a result, the attenuation of the PIN diode attenuator 11 becomes a predetermined value, the signal level output from the frequency conversion unit 12 to the power amplification unit 21 is adjusted, and the output of the power amplification unit 21 is transmitted to the target transmission with high accuracy. The power level will be maintained.
[0012]
As described above, when the variance value _Bn calculated from the variance threshold value _Bmax continuously increases, the average calculated by adjusting the number of output data to be averaged as follows. The degree of plausibility of the value can be increased.
In other words, when the threshold value B _max <calculated value B _n is satisfied continuously for a predetermined number of times p, or when a predetermined number of times r have occurred in the past predetermined number q, the number n of data to be averaged is increased. m (n <m). Thereafter the, _{'B max} relative' _{B max} of the threshold _{B max} smaller than had values> be a Bn is p 'when consecutive times, or past a predetermined q' given r of times' If the number of times has occurred, the number of data to be averaged is returned to the original n.
The variance thresholds B _max and B _max ′, the number of data to be averaged n and m, the number of times p, q, and r are stored in the memory 26 in advance when the system is set.
As described above, by adjusting the number of data to be averaged according to the magnitude of the variance, the calculated average value becomes a value with higher reliability.
[0013]
【The invention's effect】
As described above, according to the present invention, in a transmission output control device that outputs a transmission power amplifying unit by comparing an average level of an output of a transmission power amplifying unit and a target output level in an arithmetic processing unit, The variance value of the output level is calculated together with the average value of the levels, and when the calculated variance value exceeds a variance value (threshold value) set in advance, the transmission output control operation based on the average value level is not performed. Since the transmission control is performed with new data and the number of data to be averaged is changed in accordance with the calculated variance, the reliability of the average can be further increased. .
Therefore, it is possible to provide a highly accurate transmission output control unit by eliminating the influence of data showing large temporary fluctuations in output, such as noise and instantaneous voltage fluctuation, on averaged transmission output data.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing an embodiment of a transmission power control system of a transmission power amplifier of a digital wireless communication system according to the present invention. FIG. 2 is a transmission power amplifier of a conventional digital wireless communication system. FIG. 1 is a schematic configuration diagram mainly showing an example of a transmission power control system.
FIG. 3 is a diagram showing an example of an output signal transmitted in a burst and a waveform obtained by enlarging a part of the output signal.
FIG. 4 is a diagram showing a waveform example in which another part of the output signal of FIG. 3 is enlarged.
[Explanation of symbols]
1. Transmission frequency conversion device 2. Transmission power amplification device
11. PIN diode attenuator, 12. Frequency converter,
21 ··· Power amplifier, 22 ·· Directional coupler, 23 ·· Detector,
24 A / D converter, 25, 25a CPU
26, 26a, memory, 27, D / A converter, 28, buffer amplifier

Claims (4)

Calculate an average value of a predetermined number of continuous output level data of the transmission power amplifying apparatus having the transmission signal level adjusting means, compare the average value with a preset target transmission output level, and determine the difference. An arithmetic processing device for detecting and generating a signal for correcting the input level so that the output level of the transmission power amplifying device becomes the target transmission output level in accordance with the detected difference, and sending the signal to the input level adjusting means. In a transmission output control device of a digital wireless communication system having
In the arithmetic processing device, the variance value of the output level data is calculated simultaneously with the calculation of the average value of the output level data of the transmission power amplifying device, and when the magnitude of the variance exceeds a preset threshold value, A transmission output control device wherein transmission output control based on an average value is stopped, and an average value of new output level data is obtained again. 2. The transmission output control device according to claim 1, wherein an average value of the output level data of the transmission power amplification device is calculated by a time average. 2. The transmission output control device according to claim 1, wherein an average value of the output level data of the transmission power amplification device is calculated by a moving average. 4. The transmission output control apparatus according to claim 1, wherein the number of output level data for calculating an average value is changed according to the calculated variance.

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