JP2590736B2 - Transmission output control method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission output control method for digital radio transmission, and more particularly to a transmission output control method for improving line quality.

[0002]

2. Description of the Related Art The configuration of a conventional transmission output control method is shown in FIG.

In FIG. 1, an input information signal in a baseband frequency band input from an input terminal 1 is converted into a modulated signal by a modulator 2, amplified by a transmitter 3, and transmitted by a transmitting antenna 4.
And received by the receiving antenna 5,
And demodulated to a baseband signal by the demodulator 7.
Output from the output terminal 8.

The level detector 9 detects the reception input level of the receiver 6 and sends the reception input level information to the output controller 11, and when the reception input signal level falls below a predetermined level, Transmitter 3 to compensate for the decrease
Control the output level of the By this means, when the reception input level of the receiver 6 is high in a steady state where the propagation path is stable, the output level of the transmitter 3 is lowered from the standard level, and when fading occurs in the propagation path and the reception input level of the receiver 6 is low, Raise the output level of the transmitter 3.

In this figure, the output of the level detector 9 is directly input to the output controller 11 for simplicity. Of course.

[0006]

According to the conventional transmission output control method, when a radio wave is subjected to waveform distortion in which a notch occurs in a transmission band due to selective fading or the like,
There was a problem that the signal could not be compensated and the signal deteriorated due to interference from the adjacent channel.

[0007]

SUMMARY OF THE INVENTION A transmission output control method according to the present invention provides a radio transmission / reception for transmitting / receiving a data signal via a radio line.
In the transmission output control method of the station, the receiving side
Receives a signal transmitted from a wireless transmitting and receiving station, and
Comparing the level of the received signal with the first level,
Indicates whether a level exceeds or does not exceed the first level
Generate reception level information and convert the reception signal to a plurality of narrowband signals.
After passing through the filter, the level is detected and each second level
And the level of the received signal is equal to the second level.
Generates signal waveform distortion information indicating whether or not
On the receiving side, the reception input level information is the first level
In the following cases, raise the output level of the transmitter and
If the level information is greater than or equal to the first level, the signal
If the waveform distortion information is equal to or less than the second level,
Raise the output level of the transmitter, the signal waveform distortion information
The output level of the transmitter if above the second level
Is controlled to be lower than the standard level,
The reception input level information and the signal waveform distortion information are opposed to each other.
It is characterized by transmitting to a radio transmitting / receiving station .

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to the drawings.

As shown in FIG. 1, the components of the present invention are as follows.

That is, a modulator 2 for outputting a modulation signal in accordance with an input information signal input from an input terminal 1;
, A transmitting antenna 4 for transmitting the output signal of the transmitter 3, a receiving antenna 5 for receiving the transmitted signal, and a receiver 6 for amplifying the output signal of the receiving antenna 5. A demodulator 7 for demodulating an output signal of the receiver 6 and outputting an information signal; a level detector 9 for detecting a reception input level from the receiver 6 and outputting reception input level information; A waveform distortion detector 10 that detects signal waveform distortion from an output signal and outputs signal waveform distortion information, and a transmitter 3 based on reception input level information from a level detector 9 and signal waveform distortion information from the distortion detector 10. An output controller 15 for controlling an output level.

Next, the operation will be described.

A baseband input information signal from an input terminal 1 is modulated by a modulator 2, amplified by a transmitter 3, and transmitted from a transmitting antenna 4. This transmission signal is
The signal is received by the receiving antenna 5, amplified by the receiver 6, converted into a baseband signal by the demodulator 7, and output from the output terminal 8.

The level detector 9 detects the reception input level of the receiver 6 and outputs this reception input level information to the output control panel 1.
1 to control the output level of the transmitter 3. By this means, when the reception input level of the receiver 6 is high in a steady state where the propagation path is stable, the output level of the transmitter 3 is lowered from the standard level, and when fading occurs in the propagation path and the reception input level of the receiver 6 is low, Raise the output level of the transmitter 3.

The waveform distortion detector 10 detects signal waveform distortion from the output signal of the receiver 6, sends the signal waveform distortion information to the output control panel 15, and controls the output level of the transmitter 3. FIG. 2 shows a block diagram of the waveform distortion detector 10. The waveform distortion usually generates a narrow band notch in the transmission band, so that narrow band filters 12-1 and 12- having different center frequencies are used.
For example, when the IF band signal band of the output signal of the receiver 6 is 70 MHz ± 10 MHz,
As shown in FIG. 3, f ₊ (around 80 MHz), f ₀ (7
0MHz _vicinity), f - (detects a signal of 60MHz around), respectively. Three narrow band filters 12-1 and 12
The levels of the signals detected by −2 and 12-3 are detected by the level detectors 13-1, 13-2 and 13-3, respectively, and are lower than a certain level.
When there are outputs from 13-2 and 13-3, the calculator 14 determines that there is distortion and sends information to the output control panel 11. This control is shown in the flowchart of FIG. For example, if selective fading occurs in a state where the reception input level is high, even though the level detector 9 determines that the reception input level is high, the distortion detector 10 detects that a notch has occurred in the band. Thus, the output level of the transmitter 3 is increased.

The output signals of the level detector 9 and the waveform distortion detector 10 of the present invention are directly transmitted to the output controller 15, and FIG. 5 shows an embodiment including the transmission means. Show. In this figure, the transmission signal transmitted from station A is B
After being received by the station, the output signals of the level detector 9 and the waveform distortion detector 10 are modulated by the modulator 2, passed through the transmitter 3, passed through the duplexer 16, and transmitted and received by the duplex antenna 17. Sent to the station. At the station A, the demodulated signal is demodulated by the demodulator 7 and then input to the output controller 15 to control the output level of the transmitter 3 according to the control operation described above.

[0016]

As described above, according to the transmission output control method of the present invention, even if there is signal waveform distortion due to selective fading in the propagation path, signal distortion information is output from the receiver by the distortion detector. Since the signal can be sent to the control panel and the transmission output can be amplified, there is an effect that signal deterioration due to interference from an adjacent channel can be prevented.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of a transmission output control method according to the present invention.

FIG. 2 is a block diagram of a distortion detector.

FIG. 3 is a diagram illustrating an example of a frequency band in which a level is detected by a distortion detector.

FIG. 4 is a flowchart for explaining an operation of a main part of FIG. 1;

FIG. 5 is a block diagram showing another embodiment of the transmission output control device of the present invention.

FIG. 6 shows a block diagram of a conventional transmission output control method.

[Explanation of symbols]

 Reference Signs List 1 input terminal 2 modulator 3 transmitter 4 transmitting antenna 5 receiving antenna 6 receiver 7 demodulator 8 output terminal 9 level detector 10 waveform distortion detector 11 output controller 12-1, 12-2, 12-3 Narrow band filter 13-1, 13-2, 13-3 Level detector 14 Operation unit 15 Transmission power controller 16 Demultiplexer 17 Transmitting / receiving antenna

Claims (1)

(57) [Claims] 1. A wireless system for transmitting and receiving data signals over a wireless line.
In the transmission output control method of the transmission / reception station, the reception side receives a signal transmitted from an opposite radio transmission / reception station , compares the level of the reception signal with a first level, and determines that the level of the reception signal is the first level. Cross or cross level 1
Receiving level information indicating whether or not the received signal has passed through a plurality of narrow band filters.
Signals are detected and compared with a second level, and the level of the received signal exceeds or exceeds the second level.
Signal waveform distortion information indicating whether or not the received input level information is lower than the first level on the transmitting side.
Raises the output level of the transmitter, and when the reception input level information is equal to or higher than the first level
Wherein the signal waveform distortion information is equal to or lower than the second level.
If the output level of the transmitter is increased, the signal waveform distortion information is equal to or higher than the second level.
Reduce the output level of the transmitter from the standard level.
Control, transmission data, the reception input level information, and signal waveform distortion information.
Is transmitted to the opposite radio transmitting / receiving station .