JP3012379B2 - Transmission power 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 power control system.

[0002]

2. Description of the Related Art In a conventional transmission power control method, the maximum value of transmission power is determined in advance by the influence of nonlinear distortion of a power amplifier of a transmitter.
Value (= transmission power when transmission power control is not performed)
Power), and usually increases the transmission power from its maximum value.
Lower the transmission further and set the fading depth (= receiver
Input power) according to the reduced transmission power
A structure for continuously controlling up to a preset maximum value
It had become adult.

[0003]

In the conventional transmission power control method described above, the maximum transmission power is not controlled by the transmission power.
Since it is the same as the case, it is higher than the maximum value
When trying to set the transmission power, Fade Depth vs. B when transmission power is not controlled due to nonlinear distortion of the power amplifier
There is a problem that ER characteristics are deteriorated.

[0004]

According to a transmission power control method of the present invention, detection information obtained by detecting an input level at a receiver of an opposite receiving station is fed back to its own transmitting station, and based on the detected information. in the transmission power control scheme for controlling the output level of the transmitter of said transmitting station, the transmitting station the reception
Want input level information that is fed back from the station
The width of the value of the input level is set in advance,
By having a set means to set the maximum value of the transmission in response power to the width of the input level value of respectively, transmit power
When the control is not performed, the preset transmission power
Even higher transmission power is possible .

[0005]

Next, the present invention will be described with reference to the drawings.

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

In FIG. 1, the present embodiment comprises a transmitting station 21 and a receiving station 22 for transmitting and receiving signals to and from each other via antennas 5 and 6, and the transmitting station 21 performs digital signal processing for digitally processing the signals to be transmitted. A circuit 1, a modulator 2 for modulating a processed digital signal for transmission, a receiver 14 for receiving a received signal from a receiving station 22 via an antenna 5 and a duplexer 4, and demodulating the received signal. A demodulator 15; a digital processing circuit 16 for performing digital processing on the demodulated received signal to send it to the next device (not shown) and extracting reception input level information; and a transmission processing corresponding to a plurality of folded reception input levels. A data storage circuit 19 in which an output level is stored in advance, and a transmission output level corresponding to a reception input level are read from the data storage circuit 19 and output from the transmitter 3 The power control circuit 18 for controlling the bell
And a transmitter 3 for transmitting radio waves to the air via the duplexer 4 and the antenna 5 at the output level set by the power control circuit 18, and the receiving station 22 is transmitted from the transmitting station 21. A receiver 8 for receiving the received radio wave via the antenna 6 and the duplexer 7, and a demodulator 9 for demodulating the received signal.
A digital processing circuit 10 for digitally processing the demodulated reception signal and transmitting the digital signal; an A / D conversion circuit 17 for converting an analog signal of the reception input level detected by the receiver 8 into a digital signal; A digital processing circuit 11 for multiplexing the digital signal from the conversion circuit 17 and the main digital signal, a modulator 12 for modulating the multiplexed signal, and a demodulated signal via the duplexer 7 and the antenna 6 And a transmitter 13 for transmitting to the transmitting station 21.

Next, the operation of this embodiment will be described.

The information on the reception input level detected by the receiver 8 (for example, the AGC voltage or the like) is transmitted to an A / D conversion circuit 17.
, Is input to a digital signal processing circuit 11, multiplexed with a main digital signal, digitally modulated by a modulator 12, frequency-converted and power-amplified by a transmitter 13, and transmitted and received by a duplexer 7.
And is radiated to the space by the antenna 6 through the antenna.

[0010] A signal from the receiving station 22 is received by the antenna 5 of the transmitting station 21, and transmitted to the receiver 1 through the duplexer 4.
The digital signal processing circuit 16 performs digital demodulation by the demodulator 15, extracts the reception input level information of the receiving station 22 by the digital signal processing circuit 16, and inputs the information to the power control circuit 18.

The power control circuit 18 compares the input received input level information with a plurality of set values of the transmission power for the transmitter 3 previously input to the data storage circuit 19, and controls according to the result. Transmits a signal and transmits
Control the output level of the

FIG. 2 shows the input level of the receiver versus BER (Bi) using the transmission power of the transmitter in this embodiment as a parameter.
FIG. 4 is a characteristic diagram illustrating an example of a (Error Rate) characteristic.

In general, if the transmission power is made higher than the linear region in the input / output characteristics of the power amplifier of the transmitter, the BER characteristic is degraded due to the non-linear distortion. You. In this embodiment, the level is set to 0 dB.

FIG. 3 shows a transmission power relative level 0 dB (transmission power in the case where transmission power control is not performed) in this embodiment.
Force), the input level of the receiver when there is no fading is set to 0
dB and then by that propagation interval attenuation fading occurs when the is a characteristic diagram showing an example of a (Fade Depth) versus BER characteristics.

In FIG. 3, the transmission power is set to a certain value.
BER characteristics when fixed (when transmission power control is not performed)
Is exactly the same as in FIG. The transmission power is reduced as in the present embodiment.
Relative level 0 dB (transmission power without transmission power control)
Force), get the same reception input level
Fade Depth is increased by the amount of transmission power.
Therefore, the BER characteristic of FIG.
B (Fa)
(depth of depth).

In this embodiment, the best Fade De
The pth vs. BER characteristic is obtained by following the leftmost of each characteristic curve in FIG. 3 with reference to the transmission output relative level 0 dB, and the result is shown in FIG.

In this embodiment, the best Fa shown in FIGS.
In order to obtain de Depth vs. BER characteristics, the data storage circuit 19 controls the transmitter 3 so that the transmission output relative level corresponding to Fade Depth at each point of a, A, B, C and D shown in FIGS. Is stored in advance as a set value.

[0018]

The present invention described above, according to the present invention, the signal station transmission based on the detected feedback to detect information detection information to the transmitting station of the own station the input level at the receiver of the receiving station opposite in the transmission power control scheme for controlling the output level of the transmitter, transmission Shinkyoku has been fed back from the receiving station
For input level information, multiple input level values
Set the width and correspond to the width of each input level value
Preset when you by having a setting means to set the maximum value of the transmission power, which does not perform transmission power control
Transmission power higher than the specified transmission power.
And, I and best BER performance for the depth of fading
The output of the transmitter is controlled as
Is not performed or Fade is superior to the conventional method
There is an effect that depth-to- BER characteristics can be obtained .

[Brief description of the drawings]

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

FIG. 2 shows an input level of a receiver versus BER (Bit Err) with transmission power of a transmitter as a parameter in the present embodiment.
FIG. 4 is a characteristic diagram showing an example of (or Rate) characteristics.

FIG. 3 is a diagram illustrating a state where the transmission power of the transmitter according to the present embodiment is relative to 0 dB (transmission power when transmission power is not controlled);
By that propagation section attenuation in fading occurs when the input level and 0dB of the receiver when there is no Managing (Fade
FIG. 4 is a characteristic diagram illustrating an example of a (Depth) versus BER characteristic.

FIG. 4 shows the best Fa in the present embodiment obtained from FIG. 3;
FIG. 4 is a characteristic diagram showing an example of de Depth vs. BER characteristics.

[Explanation of symbols]

 1,10,11,16 Digital signal processing circuit 2,12 Modulator 3,13 Transmitter 4,7 Duplexer 5,6 Antenna 8,14 Receiver 9,15 Demodulator 17 A / D conversion circuit 18 Power control Circuit 19 Data storage circuit 21 Transmitting station 22 Receiving station

Claims (1)

(57) [Claims] 1. An output level of a transmitter of a transmitting station is controlled based on the detected information by feeding back detection information obtained by detecting an input level in a receiver of an opposite receiving station to a transmitting station of the own station. In the transmission power control method, the transmitting station
Input level information fed back from the receiving station
For information, set the value range of multiple input levels in advance
Place by having setting means to set the maximum value of the transmission power corresponds to the width of each of the input level value,
The preset transmission when transmission power control is not performed
A transmission power control method characterized by enabling higher transmission power than the transmission power.