WO2003039010A1

WO2003039010A1 - Transmission apparatus and automatic gain control method thereof

Info

Publication number: WO2003039010A1
Application number: PCT/JP2002/009681
Authority: WO
Inventors: Nobuyuki Takeno
Original assignee: Nec Corporation
Priority date: 2001-10-29
Filing date: 2002-09-20
Publication date: 2003-05-08
Also published as: JP3669497B2; JP2003133969A

Abstract

A transmission apparatus includes a transmitter (1) and a transmission power amplifier (2). In the transmitter (1), a modulation output signal is amplified via a variable attenuator (12) whose attenuation amount is controlled by a control signal and output to the transmission power amplifier (2) while transmission power data (S16) is calculated by a detector (15) and an A/D converter (16). The transmission power amplifier (2) calculates transmission power data (S23) of input side in a detector (22) and an A/D converter (23) and transmission power data (S27) of output side in a detector (26) and an A/D converter (27). A comparator (28) outputs to a comparison/control unit (17) of the transmitter (1) as a gain correction value, a difference between a reference gain value and a gain of the transmission power amplifier calculated from the transmission power data difference between the input side and the output side. The comparison/control unit (17) corrects the transmission power correction value calculated from the difference between the transmission power data (S16) and the reference transmission power value, by using the gain correction value, decides a control signal and outputs it to the variable attenuator. Thus, it is possible to make the transmission power level constant even if a gain fluctuation is caused in the transmission power amplifier.

Description

TECHNICAL FIELD The present invention relates to a transmission device and an automatic gain control method thereof.

The present invention relates to a transmission device and an automatic gain control method thereof, and more particularly, to a transmission device capable of correcting a gain error due to a frequency characteristic of a transmission device and a gain variation due to temperature, and keeping a transmission output of the transmission device constant, Related to gain control method. Background art

Conventionally, in a mobile communication system such as a mobile phone, a base station transmitting apparatus includes a transmitter for transmitting a signal of a certain frequency in a predetermined frequency band and a transmission for amplifying a transmission signal with a constant reference gain in a predetermined frequency band. It consists of a power amplifier.

FIG. 4 shows an example of this type of conventional base station transmitting apparatus.

In FIG. 4, the base station transmitting apparatus includes a transmitter 5, a transmission power amplifier 6, and an antenna 7.

Further, the transmitter 5 compares the modulated signal generation section 51, the variable attenuator 52, the amplification section 53, the power block 54, the detection section 55, and the / 0 conversion section 56 with each other. It is composed of a control unit 57.

The modulation signal generator 51 of the transmitter 5 outputs a modulation output signal S51. The variable attenuator 52 receives the modulation output signal S51 as an input, controls the attenuation by the control signal S57, and controls the transmission output of the transmitter 5. The amplifying unit 53 performs power amplification by using the modulated output signal S51, whose power has been controlled by the variable attenuator 52, as an input. The power bra 54 divides the output of the amplifier 53 into two, outputs one as a transmission output S 54, and outputs the other to the detector 55. The detection unit 55 detects the output of the power blur 54 and outputs a detection output S55 which is voltage information. The AZD converter 56 quantizes the detection output S55 and outputs digital transmission power data S56. The comparison control unit 57 receives the transmission power data S 56 as a first input, a reference transmission power value S 58 preset as a transmission output of the transmitter 5 as a second input, and outputs a control signal S 56 5 7 is generated to control the variable attenuation section 52. The transmission power amplifier 6 includes an amplifying unit 64, and amplifies the power of the input transmission output S 54 and outputs it to the antenna 7.

In such a transmission device, the reference transmission power value S58 of the transmitter 5 is set to an arbitrary value within a transmission power range specified in advance by transmission power control means (not shown). The detection output S55 detected by the detection unit 55 is converted into digital transmission power data S56 by the A / D conversion unit 56, and the comparison and control unit 57 transmits the transmission power S56. The control signal S52 controls the attenuation of the variable attenuator S52 so that the difference is minimized, that is, the output of the transmission device is constant. Is output.

In the above-described conventional transmitting apparatus, the gain of the amplifying section 64 of the transmission power amplifier 6 is ideally constant in a predetermined frequency band, but actually changes according to the frequency as shown in FIG. Fig. 4 shows transmission output versus frequency characteristics. That is, since the power level of the transmission output S54 of the transmitter 5 is constant, there is a gain difference A i3 with respect to the reference frequency f O at the transmission frequency (for example: Π) of the amplification section 64. Therefore, there was a problem that an error of β occurred in the transmission output of the antenna 7.

Further, every time the transmission power amplifier 6 is replaced for repair or the like, the transmission output of the transmitter 5 needs to be adjusted. Disclosure of the invention

SUMMARY OF THE INVENTION An object of the present invention is to provide a transmission device capable of correcting a gain error due to a frequency characteristic of a transmission device and a gain variation due to temperature to stabilize a transmission output of the transmission device and an automatic gain thereof in order to solve the above-mentioned problems and the like. It is to provide a control method.

It is another object of the present invention to output a gain correction value from a transmission power amplifier.

A further object of the present invention is to provide a transmission device capable of replacing a transmission power increase ifi device without adjusting a transmission output including a transmission power amplifier, and an automatic gain control method thereof.

In order to achieve such an object, a transmitting apparatus of the present invention amplifies a radio frequency signal to be transmitted by an amplifying means whose gain is controlled in accordance with a control signal, and makes the output power level constant. A transmitter that performs automatic gain control to adjust the control signal according to the output power level, and amplifies the output signal of the transmitter by 1 02 09681

A transmission power amplifier that supplies the transmission power amplifier to the transmission power amplifier, and calculates a difference between the gain and a preset reference gain, and outputs the difference as a gain correction value. Means, and means for correcting the gain control signal of the transmitter according to the gain correction value.

A transmitter of the above-described transmitting apparatus, a modulation signal generating means for outputting a radio frequency modulation output signal corresponding to information to be transmitted, and a transmission output power level of the transmitter by the control signal with the modulation output signal as an input. Amplifying means for performing power amplification with the modulated output signal power-controlled by the variable reducing means as input, and dividing the output of the amplifying means into two and outputting one as a transmission output Distribution means; transmission power measuring means for detecting the other output of the distribution means and outputting it as digital transmission power data indicating the power level of the transmission output; and a preset reference to the transmission power data. A transmission power correction value is calculated from a difference from the transmission power value, and the transmission power correction value is corrected with a gain correction value from the transmission power amplifier to generate the control signal. And having a comparison and control means for outputting to the variable attenuator means.

The comparing and controlling means in the above-mentioned transmitter, wherein the transmitting power data from the transmitting power measuring means is sequentially accumulated for an arbitrary predetermined time and averaged, and the average processing section outputs an averaged transmitting power data. A comparator that compares the average transmission power value and a reference transmission power value specified in advance and outputs a difference value between them as a transmission power correction value; and a comparator that outputs the transmission power correction value and the transmission power from the transmission power amplifier. An adder that performs addition with the gain correction value and controls the control signal so that the output value of the adder is minimized.

The transmission power amplifier of the above-described transmission device, the input-side distribution means for dividing the transmission output from the transmitter into two, an amplification means for power-amplifying one output of the input-side distribution means, and the amplification Output means for dividing the output of the means into two parts and outputting one to the antenna, and detecting the other output of the input-side distribution means and outputting it as digital transmission power data indicating the input power level of the transmission output. An input-side transmission power measuring means, and an output-side transmission power measuring means for detecting the other output of the output-side distribution means and outputting as digital transmission power data indicating an output-side power level of the transmission output. The gain of the own transmission power amplifier is calculated from the difference between the transmission power data on the input side and the transmission power data on the output side, and the gain correction value is calculated from the difference between the calculated gain and a preset reference gain value. Comparing means for calculating and outputting to the transmitter.

The comparison means of the transmission power amplifier described above comprises: a buffer for sequentially and temporarily storing the transmission power data on the input side to provide a delay time corresponding to the delay time in the amplification means; and a buffer on the input side passing through the buffer. An input-side averaging unit that sequentially accumulates transmission power data over an arbitrary fixed time and outputs an averaged transmission power data on the input side, and an output processing unit that sequentially transmits the transmission power data on the output side. An output-side averaging unit that outputs average transmission power data on the output side accumulated and averaged over time; average transmission power data on the input side and evening output synchronization established by the buffer; A comparator that calculates the gain value of its own transmission power amplifier by comparing the average transmission power data with the average transmission power data, and calculates a difference between the gain value from the comparator and a predetermined reference gain value. And a subtractor for outputting the gain correction value. The automatic gain control method of the present invention amplifies a radio frequency signal to be transmitted by amplifying means whose gain is controlled according to a control signal, and according to the output power level so that the output power level becomes constant. An automatic gain control method in a transmitting apparatus, comprising: a transmitter that adjusts the control signal; and a transmission power amplifier that power-amplifies an output signal of the transmitter and supplies the output signal to an antenna, wherein a gain value of the transmission power amplifier is measured. Calculating a difference between the gain value and a preset reference gain value to obtain a gain correction value; and a value of a gain control signal of the transmitter corresponding to the gain correction value. And performing a correction of

In the above automatic gain control method, a step of distributing a part of a radio frequency signal input to the transmission power amplifier and calculating a transmission power value on an input side; and amplifying radio output from the transmission power amplifier. Calculating a transmission power value on the output side by distributing a part of the frequency signal; and providing the transmission power value on the input side with a delay time corresponding to the time required for amplifying the radio frequency signal, thereby providing a transmission power value on the output side. And using the difference as a gain value of the transmission power amplifier. PT / JP02 / 09681

5 Brief description of drawings

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration example of the comparison unit shown in FIG.

FIG. 3 is a block diagram showing a configuration example of the comparison and control unit shown in FIG.

FIG. 4 is a block diagram illustrating an example of a conventional transmission device.

FIG. 5 is a diagram illustrating an example of transmission output versus frequency characteristics of a conventional transmission power amplifier. BEST MODE FOR CARRYING OUT THE INVENTION

First, the outline of the transmitting device of the present invention will be described.

The transmission device of the present invention is used, for example, in a base station of a mobile communication system and incorporates an automatic gain control circuit to amplify a radio frequency-modulated output signal and output the output signal as a constant power level output signal. It has a transmitter and a transmission power amplifier that power-amplifies the output of the transmitter and supplies it to the antenna. In this transmitter, the gain of the transmission power amplifier is detected, and if there is a difference from the reference gain value, the gain correction value is output to the automatic gain control circuit of the transmitter, and the output of the transmitter is changed to change the gain correction. It is characterized by making the transmission output level from the transmission power amplifier constant by correcting the value.

More specifically, the transmitter amplifies the generated modulated output signal through a variable attenuator whose attenuation is controlled by the value of the control signal (the voltage value of the analog gain control signal), and amplifies the signal to the transmission power amplifier. At the same time, the output signal is distributed by a power controller, converted to digital transmission power by the detector and A / D converter, and input to the comparator and controller. The control unit adjusts the value of the control signal according to the difference value between the transmission power data and the reference transmission power value and outputs the result to the variable attenuator, and the output power level to the transmission power amplifier is compared with the reference transmission power value. Automatic gain control is performed to make them equal.

On the other hand, the input signal from the transmitter to the transmission power amplifier is distributed by the input power amplifier, converted to digital transmission power by the input detector and AZD converter, and input to the comparator. Is done. The output signal from the transmission power amplifier, which has amplified the input signal, is distributed by the output power bracket, converted to digital output power data by the output detector and AZD converter, and input to the comparator. . The comparison section is the input side and output side Then, the gain of the transmission power amplifier calculated from the difference between the respective transmission power data and the reference gain value is compared, and the gain correction value of the difference is output to the comparison and control unit that performs automatic gain control of the transmitter. The comparison / control unit, to which the gain correction value has been input, corrects the value of the control signal and outputs it to the variable attenuator.

Next, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention, and shows only a part related to the present invention in a base station transmitting apparatus of a mobile communication system.

In FIG. 1, the transmitting apparatus of the present example includes a transmitter 1, a transmission power amplifier 2, and an antenna 3.

The transmitter 1 outputs a radio frequency (Radio Frequency: hereinafter referred to as RF) signal obtained by modulating a signal to be transmitted as a transmission output S 14, and includes a modulated signal generator 11 and a variable attenuator 1. 2, an amplifier 13, a power brassier 14, a detector 15, an A / D converter 16, and a comparator / controller 17.

The modulation signal generation section 11 of the transmitter 1 outputs a modulation output signal S11 of a radio frequency corresponding to information to be transmitted. The variable attenuator 12 gives an output power to the transmission output S 14 of the transmitter 1 by giving an attenuation corresponding to the value (analog voltage value) of the control signal S 17 to the input modulation output signal S 11. Perform level control. The amplifying unit 13 performs power amplification using the modulated output signal S11, whose power has been controlled by the variable attenuator 12, as an input. The power brassier 14 divides the output of the amplifier 13 into two, outputs one as the transmission output S14, and outputs the other to the detector 15. The detection unit 15 detects the output of the power blur 14 and outputs a detection output S15 that is voltage information. The A / D converter 16 quantizes the detection output S15 at a predetermined clock timing and outputs a digital transmission power data S16. The comparison / control section 17 uses the transmission power data S 16 as the first input and the reference transmission power value S 18 preset as the transmission output (power level) of the transmitter 1 as the second input. Using the gain correction value Δ される output from the transmission power amplifier 2 as a third input, a control signal S 17 (analog voltage signal) is generated to control the variable attenuator 12.

The transmission power amplifier 2 described above amplifies the transmission output S 14 and transmits it to the mobile station from the antenna 3 as a radio wave. 22, an 80 conversion unit 23, an amplification unit 24, a power blur 25, a detection unit 26, an AZD conversion unit 27, and a comparison unit 28.

The power amplifier 21 of the transmission power amplifier 2 divides the transmission output S 14 of the transmitter 1 into two, outputs one to the amplifier 24, and outputs the other to the detector 22. The detector 22 detects the output of the coupler 21 and outputs a detection output S22 that is voltage information. The A / D converter 23 quantizes the detection output S22 at a predetermined clock timing and outputs digital transmission power S23. The amplification section 24 power-amplifies the output of the coupler 21. The power bra 25 splits the output of the amplifier 24 into two, outputs one to the antenna 3 and outputs the other to the detector 26. The detection unit 26 detects the output of the power blur 25 and outputs a detection output S 26 that is voltage information. The A / D converter 27 quantizes the detection output S26 at a predetermined clock timing and outputs digital transmission power data S27. The comparison unit 28 receives the transmission power data S 23 as a first input, receives the transmission power data S 27 as a second input, and outputs a reference gain value S 29 preset by the transmission power amplifier 2 to a third input. Then, a gain correction value Δχ is generated and output to the comparison / control section 17 of the transmitter 1.

FIG. 2 is a block diagram showing an example of the configuration of the comparison section 28 of the transmission power amplifier 2 in FIG.

In FIG. 2, the comparison unit 28 includes a buffer 281, an averaging unit 282, 283, a comparator 284, and an arithmetic unit (subtractor) 285. .

The buffer 281 of the comparison unit 28 sequentially and temporarily stores the input transmission power data S23, and gives a delay time corresponding to the delay time of the signal amplification in the amplification unit 24. The average processing sound 152 282 outputs the average transmission power data S 282, which is obtained by sequentially storing the transmission power data S 23 via the buffer 281 over an arbitrary period of time and averaging them. The averaging section 283 sequentially outputs the input transmission power data S27, and accumulates and averages the transmission power data S27 for an arbitrary fixed time, and outputs the average transmission power data S283. The comparator 284 stores the average transmission power data S 282 on the input side and the average transmission power on the output side by establishing timing synchronization between the input and output of the amplification section 24 by accumulating it in the transmission power buffer 281. A comparison is made between the power data S 283 and a gain value S 284 of the transmission power amplifier 2 (amplifying unit 24) is calculated. The arithmetic unit (subtractor) 285 is used by the comparator 284 A gain value S285 and a reference gain value S29 specified in advance are input, and a gain correction value Δχ, which is a difference between the two, is calculated and output. The reference gain value S 29 of the transmission power amplifier 2 is set to a value specified in advance by a storage unit (not shown).

FIG. 3 is a block diagram showing one configuration example of the comparison / control section 17 of FIG.

In FIG. 3, the comparison / control section 17 is composed of an averaging section 172, an arithmetic unit (adder) 174, and a DZA conversion section 175 with an accumulation function.

In this comparison / control section 17, the average processing section 17 2 sequentially stores the input transmission power data S 16 over an arbitrary fixed time and averages the average transmission power data S 1. 7 2 is output. Comparator 173 compares average transmission power data S 172 with reference transmission power value S 18 specified in advance, and outputs transmission power correction value Δφ. The arithmetic unit (adder) 174 performs an operation (addition) of the transmission power correction value ΔΦ and the gain correction value Δχ. The DZA converter with accumulation function 175 adds the data stored in the buffer and the data stored in the buffer to the input data and the input data. If it is “negative,” decrease it and decrease it.) And accumulate and store it. Cumulatively store the outputs of the operator 174 at regular time intervals, convert the accumulated result digital-to-analog and convert it to an analog voltage signal. Output as a certain control signal S 17 (S 17 5). The reference transmission power value S 18 of the transmitter 1 is set to an arbitrary value within a transmission power range specified in advance by a transmission power control unit (not shown).

Next, the operation of the transmitting apparatus of the present example will be described in detail with reference to FIGS. In the transmitter 1 (FIG. 1), the modulation output signal S11 from the modulation signal generation unit 11 is input to the variable attenuator 12 whose attenuation changes according to the control signal S17, and is subjected to power control. After that, the signal is input to the amplification unit 13. The amplification unit 13 performs power amplification for outputting the power-controlled modulated output signal S 13 to the transmission power amplifier 2 as the transmission output S 11. The modulated output signal S 13 whose power has been amplified by the amplifier 13 is distributed to the transmitter output S 14 and the output to the detector 15 by the power bracket 14.

The detector 15 detects the input signal by means of envelope detection or the like, and outputs a detection output S15. The detection output S 15 is input to the AZD converter 16 and Log-to-digital conversion is performed and output as transmission power data S 16. The transmission power data S 16 is input to the comparison / control section 17 and compared with the reference transmission power value S 18. The transmission power correction value ΔΦ (reference transmission power value S 18 —transmission power data S 16) is calculated. The transmission power correction value ΔΦ is a difference in output level due to a change in characteristics of the amplifier 13 due to a temperature or a change over time. When the gain correction value Δ から from the transmission power amplifier 2 has not been input yet (when the value of Δ 「is“ 0 ”), the control unit 17 is variable so that the correction value is minimized. The control signal S 17 for controlling the attenuation of the attenuator 12 is output. The operation when the gain correction value Δχ is input will be described later.

In the transmission power amplifier 2 (FIG. 1), the transmitter output S 14 is divided by the power bra 21 into two outputs, an output to the amplifier 24 and an output to the detector 22. The output of the amplifier 24 is divided by the power bra 25 into two, an output to the antenna 3 and an output to the detector 26. The detector 22 and the detector 26 detect the output of the power bra 21 and the power bra 25 by means of envelope detection or the like, and output a detected output S 22 and a detected output S 26. The detection output S22 and the detection output S26 are input to the AZD conversion unit 23 and the AZD conversion unit 27, are converted from analog to digital, and output as transmission power data S23 and transmission power data S27. It is input to the comparison unit 28.

The transmission power data S 23 input to the comparison unit 28 (FIGS. 1 and 2) is accumulated in the buffer 281, as shown in FIG. Output as 2 8 2. Similarly, the input transmission power data S 27 is output from the average processed sound 83 as the average transmission power data S 283. The average transmission power S 282 and the average transmission power data S 283 are input to the comparator 284. In the average transmission power data S 282, the delay amount of the amplifier 24 is corrected by the notifier 28 1, and the timing synchronization is established with the input of the average transmission power — S 283. . The average transmission power data S 2 82 and the average transmission power data S 2 83 are converted into transmission power levels based on the conversion table of “average transmission power data versus transmission power level”, and the difference between the two transmission power levels is calculated. From this, the gain value S 2 84 is calculated. The conversion table of “average power data vs. transmission power level” is separately provided in the detectors 22 and 26 of FIG. 2 to minimize errors due to the detection capability of the detector. The arithmetic unit 285 compares the gain value S 2 8.4 with the reference gain value S 2.9 and calculates the difference. 0209681

10 Output as the gain correction value Δχ (reference gain value S29—gain value S284). The gain correction value Δ χ is input to the comparison and control unit 17 of the transmitter 1.

The transmission power data S16 input to the comparison / control section 17 (FIGS. 1 and 3) is output from the average processing section 172 as average transmission power data S172, as shown in FIG. The average transmission power data S172 is compared with a reference transmission power value S18 specified in advance by the transmitter 1 by the comparator 173, and the difference is output as a transmission power correction value.

The arithmetic unit 174 in FIG. 3 receives the transmission power correction value and the gain correction value Δχ, and adds the transmission power correction value △ Φ and the gain correction value Δχ to the digital data of the total correction value (△ + △ χ). Outputs overnight. The output digital data is sequentially added and accumulated in the DZA conversion unit 175 with an accumulation function, and is subjected to digital-to-analog conversion to be a control signal S 17 (or S 175). The variable attenuator 12 controls the amount of attenuation according to the voltage value of the control signal S12, thereby compensating for variations in characteristics due to the temperature of the transmitter 1 and variations in output level due to aging. The gain fluctuation of the amplifier 2 is also corrected.

The situation of these corrections will be described using specific numerical values with reference to Table 1.

table 1

As shown in the “ideal” column of Table 1, the reference gain value S29 is 40 dB, the reference transmission power value S18 is 0 dBm, and the antenna 3 output is +40 dBm. Also, assume that the voltage value of the control signal S17 input to the variable attenuator 12 (variable attenuator gain: OdB) of the transmitter 1 at this ideal time is IV, and from this state, the variable attenuator 12 Decrease Assume that the voltage value of the control signal S 17 when the attenuation is reduced by 1 dB (variable attenuator gain: −1 dB) is 0.5 V.

Here, as shown in the “before correction” column of Table 1, there is no change in the transmission output S 14 by the transmitter 1 (the actual power level (transmission power value) of the transmission output S 14 is the reference transmission power value. 0 dBm), and the actual gain of transmit power amplifier 2 is 39 dB. The gain correction value Δ 送信 of the transmission power amplifier 2 is 1 dB (reference gain value-actual gain = 40-39), and the transmission power correction value ΔΦ of transmitter 1 is 0 dB (reference transmission power value-actual transmission power) Value = 0-0), and the total correction value (△ φ + Δχ) of the comparison control unit 1 1 is 1 dB (= 0 + 1).

The DZA converter 175 (Fig. 3) with the accumulation function of the comparison controller 17 adds the total correction value to the previous data value and outputs the output voltage based on the preset digital-analog conversion rule. (The control signal S17 is changed from IV to 0.5 V. Thereby, the attenuation of the variable attenuator 12 is reduced by 1 dB.

Even if the output of the antenna 3 temporarily becomes +39 dBm, the attenuation of the variable attenuator 12 by the control signal S 17 corresponding to the total correction value (Δφ + Δχ) output from the comparison control unit 17 is obtained. Volume is reduced by 1 dB, as shown in the `` after '' column of Table 1, the transmit power S 14 is +1 dBm, and the output of antenna 3 is maintained at +40 dBm (= 1 + 39) . At this time, the transmission power correction value ΔΦ of the transmitter 1 is 1 dB (= 0-1), but the gain correction value Δχ of the transmission power amplifier 2 remains 1 dB. Δψ + Δ と is 0 dB.

The D / A converter with accumulation function 175 adds the total correction value to the data value up to the previous time, but the total correction value at this time is “0”, so the data value does not change. That is, the output voltage (control signal S17) maintains 0.5V. This state continues until the overall correction value changes.

Incidentally, the fact that the sign of the transmission power correction value ΔΦ is “1” indicates that the actual transmission power value of the transmitter 1 exceeds the reference transmission power value, and the gain correction value Δ 値 is not input. Then, the attenuation of the variable attenuator 12 must be increased.

On the other hand, the sign of the gain correction value Δχ being “+” indicates that the actual gain value of the transmission power amplifier 2 is lower than the reference gain value, and the attenuation of the variable attenuator 12 is reduced. 9681

12 Therefore, in the present invention, as described above, the increase Z decrement of the gain correction value Δ% is canceled by the decrease / increase of the transmission power correction value Δφ, that is, the transmission power correction value △ Φ and the gain correction Automatic gain control for controlling the attenuation of the variable attenuator 12 is performed so that the total correction value obtained by adding the value Δχ becomes the minimum (0 dΒ).

As described above, according to the present invention, the gain of the transmission power amplifier including the gain error due to the frequency characteristic and the gain variation due to the temperature is detected in the usable frequency band of the transmission device, and the reference gain value is calculated. If there is a difference, output the gain correction value to the transmitter and correct the gain correction value at the transmitter output to keep the transmission output of the transmitter including the transmission power amplifier constant. Can be. Further, by outputting the gain correction value from the transmission power amplifier, the transmission power amplifier can be replaced without adjusting the transmission output including the transmission power amplifier.

Claims

The scope of the claims

1. Automatic gain control that amplifies a radio frequency signal to be transmitted by amplifying means whose gain is controlled according to a control signal and adjusts the control signal according to the output power level so that the output power level is constant. And a transmission power amplifier for power-amplifying an output signal of the transmitter and supplying the amplified signal to an antenna.

Means for measuring the gain of the transmission power amplifier,

Means for calculating a difference between the gain and a preset reference gain, and outputting the difference as a gain correction value;

Means for correcting a gain control signal of the transmitter corresponding to the gain correction value.

2. The transmitter is

Modulation signal generation means for outputting a modulation output signal of a radio frequency corresponding to information to be transmitted;

Variable attenuation means for controlling the transmission output power level of a transmitter by the control signal with the modulation output signal as input,

Amplifying means for performing power amplification with the modulated output signal power-controlled by the variable reducing means as input,

Distribution means for dividing the output of the amplifying means into two and outputting one as a transmission output; and transmission power measuring means for detecting the other output of the distribution means and outputting as digital transmission power data indicating the power level of the transmission output. When,

A transmission power correction value is calculated from a difference between the transmission power data and a preset reference transmission power value, and the control signal is corrected by correcting the transmission power correction value with a gain correction value from the transmission power amplifier. And a control means for generating and outputting to the variable damping means.

2. The transmission device according to claim 1, comprising:

3. The comparison control means comprises:

The transmission power data from the transmission power measuring means is sequentially transmitted over an arbitrary predetermined time. An average processing unit that accumulates and outputs the averaged transmission power data, compares the average transmission power data with a pre-specified reference transmission power value, and uses the difference value as a transmission power correction value. An output comparator,

An adder that performs addition of the transmission power correction value and a gain correction value from the transmission power amplifier, and controls the control signal so that the output value of the adder is minimized.

3. The transmission device according to claim 2, comprising:

4. The transmission power amplifier,

Input-side distribution means for dividing the transmission output from the transmitter into two,

Amplifying means for power-amplifying one output of the input-side distribution means;

Output-side distribution means for dividing the output of the amplification means into two parts and outputting one to the antenna;

Input-side transmission power measuring means for detecting the other output of the input-side distribution means and outputting it as digital transmission power data indicating the input-side power level of the transmission output; and the other output of the output-side distribution means A transmission power measuring means on the output side for detecting the output power level and detecting the output power level on the output side as digital transmission power data indicating the output power level of the transmission output; and transmitting the signal based on the difference between the transmission power data on the input side and the transmission power data on the output side. Comparing means for calculating a gain of the power amplifier, calculating the gain correction value from a difference between the calculated gain and a preset reference gain value, and outputting the calculated gain correction value to the transmitter. The transmission device according to claim 1.

5. The comparing means

A buffer for temporarily temporarily storing the transmission power data on the input side and providing a delay time corresponding to the delay time in the amplifying means;

An input-side averaging unit that sequentially outputs the input-side transmission power data through the buffer and outputs an averaged input-side transmission power data that is accumulated and averaged over an arbitrary fixed time;

An output-side averaging unit that sequentially outputs the output-side transmission power data and accumulates and averages the output-side transmission power data over an arbitrary predetermined time;

A comparison is made between the average transmission power data on the input side and the average transmission power data on the output side, which have been synchronized with the timing by the buffer, and the gain value of the own transmission power amplifier is determined. A comparator for calculating

5. The transmitting apparatus according to claim 4, further comprising: a subtractor that calculates a difference between a gain value from the comparator and a reference gain value specified in advance and outputs the difference as the gain correction value.

6. A transmitter that amplifies a radio frequency signal to be transmitted by amplifying means whose gain is controlled according to a control signal, and adjusts the control signal according to the output power level so that the output power level is constant. An automatic gain control method in a transmission device, comprising: a transmission power amplifier that power-amplifies an output signal of the transmitter and supplies the output signal to an antenna.

Measuring a gain value of the transmission power amplifier;

Calculating a difference between the gain value and a preset reference gain value to obtain a gain correction value;

Correcting the value of the gain control signal of the transmitter according to the gain correction value;

An automatic gain control method comprising:

7. Distributing a part of the radio frequency signal input to the transmission power amplifier and calculating a transmission power value on the input side;

Calculating a transmission power value on the output side by distributing a part of the amplified radio frequency signal output from the transmission power amplifier;

Providing a delay time corresponding to the time required for amplifying a radio frequency signal to the transmission power value on the input side and comparing the transmission power value on the output side with the transmission power value on the output side;

7. The automatic gain control method according to claim 6, comprising: