JPS63301630A - Transmitting power control system - Google Patents

Abstract

PURPOSE:To execute communication under low transmitting power as much as possible by increasing the transmitting power of a transmitting station in response that a relative value between spectrum components within a receiving band in a receiving station increases more than a prescribed value at a line loss increasing time. CONSTITUTION:When abnormality is generated in the line loss distribution of a communicating line, the increasing of a relative value between spectrum components within a receiving signal band received by a receiving station 16 is generated and when the components are over a prescribed value, control information are generated from a transmitting power control information output means 13 and inputted from an antenna 12 through an antenna 10 of a transmitting station 5 to a transmitting level control means 7. The transmitting level control means 7 responds to the control information and generates the change of the setting level of a transmitting power change means 6 so that the transmitting power level can be raised. With the recovering of the line loss distribution, by the transmitting level control means 7, the setting level of the transmitting power change means 6 is changed to a low transmitting power level. Thus, the transmitting power can be reduced.

Description

[Detailed Description of the Invention] [Summary] The transmission power of the transmitting station is set to a value sufficient to maintain sufficient line quality in normal times, and when the line loss of the line increases, the spectral components within the receiving band at the receiving station are In response to the relative value between the two increasing to a predetermined value or more, the transmission power of the transmitting station is increased to a value sufficient to enable normal reception at the receiving station even in the presence of the line loss.

[Industrial application field]

The present invention relates to a transmission power control method, and more specifically,
This invention relates to a transmission power control method that uses the correlation between spectral components within a reception band to control transmission power for power reduction, etc.

In wireless communication networks such as digital multiplex wireless communication, when attempting to transmit desired information from the transmitter to the receiver,
This information will be transmitted over radio waves. In order for the receiving side to successfully receive the radio waves, the radio waves must be radiated from the transmitting side to the receiving side with the necessary transmission power, and the transmission requires only the transmission capacity of the transmitting and receiving system. Transmission power must also be determined taking into consideration the state of the transmission medium. In addition, it is important to take into account the status of other transmitting and receiving systems, whether existing or uninstalled, in the area where the transmitting and receiving system is being constructed, in order to maintain the various wireless communication systems in the area as they should be. It is a matter.

[Conventional technology]

A conventional digital multiplex wireless communication system was configured as shown in FIG. On the transmitting side, the transmitting signal modulated by the modulator 2 is transmitted from the IF band to the RF by the transmitter 4.
The frequency is converted to a band. The output signal of the transmitter 4 is power amplified by the power amplifier 14 and radiated from the transmitting antenna 16 to the receiving antenna 30. The signal received by the receiving antenna 30 is frequency-converted from the RF band to the IF band by the receiver 32, and then subjected to AGC amplification by the AGC amplifier 34, and then provided to the demodulator 36 to reproduce the transmitted signal.

The transmission power in such a transmission/reception system is determined by the AG on the receiving side.
Even when the gain adjustment function of the C amplifier 34 reaches its upper limit, the transmitting antenna 16 can still radiate radio waves of sufficient strength to maintain line quality. Previously, it was set.

[Problem that the invention seeks to solve]

However, although the above-mentioned transmission power setting is acceptable from the perspective of maintaining line quality, from the perspective of saving power, it may result in unnecessary large transmissions over a long period of time. This means that information is transmitted using electricity. This is because the transmission power set as described above is due to the large line loss (mainly loss due to fading) that is only about 5 to 10 hours a year, and such a large transmission power is not available at other times of the year. This is because, although this is not necessary, it is intended to maintain the desired line quality during the time period when large line losses as described above occur.

Further, the above-mentioned large transmission power does not pose a problem if there are no other transmitting/receiving systems in the area where the transmitting/receiving system is installed, but if this is not the case, it causes an inconvenience.

The present invention was created in view of such problems, and an object of the present invention is to provide a transmission power control method for performing communication at the lowest possible transmission power.

[Means for solving problems]

FIG. 1 shows a basic configuration diagram of the present invention. In this diagram,
2 is a transmitter of the transmitting station 4, 6 is a transmission power changing means for changing the transmission power level, and 7 is a transmission level control means. 10.12 is a transmitting/receiving antenna. 1
3 is a transmission power control information output means that is connected to the receiver 18 of the receiving station 16 and outputs transmission power control information based on the relationship that the relative values between spectrum components within the reception band have with respect to a predetermined value. . And transmission power changing means 6
The transmission power is adjusted by the transmission level control means 7 which responds to the transmission power control information transmitted from the transmission power control information output means 13 through the system formed between the transmitting and receiving stations. The invention consists of:

[For production]

During communication when the line loss distribution within the transmission band is in a predetermined distribution, the transmission power changing means 6 transmits the transmission power control information output means so that transmission is performed at a predetermined relatively low level of transmission power. Setting to that level is performed by the transmission level control means 7 which receives control information fed back from the transmitting station 13, and radio waves are radiated from the transmitting antenna 10 of the transmitting station 4 toward the receiving antenna 12 of the receiving station 16, thereby achieving the required level. Communication takes place.

When an abnormality occurs in the line loss distribution of the communication line, the relative value of the spectrum components within the received signal band received by the receiving station 16 increases, and when that component exceeds a predetermined value, Control information is generated from the transmission power control information output means 13 and inputted from the reception antenna 12 to the transmission level control means 7 via the transmission antenna IO.

In response to the control information, the transmission level control means 7 causes the transmission power changing means 6 to change the setting level so as to increase the transmission power level. Then, as the line loss distribution recovers, the transmission level control means 7 changes the setting level of the transmission power changing means 6 to a lower transmission power level.

[Example] FIG. 2 shows an example of the present invention. In this figure, 4
1,16. is a transmitting/receiving station, and 2.18 is a transmitter and a receiver of each transmitting/receiving station, respectively. 8 is a transmission level control circuit (an example of the transmission level control means 7), and 14 is a slope detection circuit (an example of the transmission power control information/output means 13) for detecting the magnitude relationship between spectrum components within the reception band. Although these circuits 8 and 14 are shown in only one transmitter/receiver station for clarity of drawing, they are provided for each cycle.

The configuration of the transmitter 2 and the transmission level control circuit 8 is shown in FIG. The transmitter 2 includes an IF amplifier 2. .

Mixer 2□, transmitting local oscillator 21, variable attenuator 24, and RF amplifier 2. (f+r, rTL in the figure,
There is a relationship between l ft ftLl = f rt). The variable attenuator 24 shows an example of the configuration of the transmission power changing means 6 shown in FIG.
This is to change the transmission power level. The analog voltage is output from a transmit level control circuit 8 which is connected to the AGC amplifier 18 . A signal output from the command signal reproducing circuit 20 connected to the output of , for example, to reduce attenuation IN in response to a high level signal "1" when there is a transmission power control command, for example, to make the amount of attenuation zero. If there is no analog signal, an analog signal for increasing the amount of attenuation corresponding to the low level signal "0" is output.

The configuration of receiver 18 is shown in FIG. In this figure, receiver 1 has an RF amplifier 18. , mixer 18□,
Receive local oscillator IL and IF bandpass filter (IFB
PF) 184, AGC amplifier 18. Consists of. AGC
Amplifier 18. has an output l and an output 2, where output 1 is connected to a demodulator (not shown) and output 2 is connected to a slope detection circuit 14.
and is connected to the command signal reproducing circuit 20. This slope detection circuit 14 detects the magnitude relationship between spectrum components within the reception band and outputs a transmission power control command, and the output signal is transmitted to the opposite station via the transmitter 2 of the local station. It is composed of

The details of the tilt detection circuit 14 are as shown in FIG.
IF amplifier 14. ．． 1'L, 144 and attenuator 14s
, 14a, and two band-pass filters 14 having passbands on the high-frequency side and low-frequency side with respect to the center of the reception band.
t, 14*, and the detector 14. ,.

14.2 and detectors 14+o and 141 at one input, respectively.
□ output is given, and the other input is given a different reference voltage rl
Comparison circuits 1413.1415 which are given +r3 and output a binary output level, and each comparison circuit 1413.14+
an operational amplifier 1416 which receives each of the binary outputs of s separately at its non-inverting input (+) and inverting input (-); and the operational amplifier 143. The non-inverting input and inverting output of each are connected to separate diodes 141? , 141a, and both diodes 14+t,
A resistor 14 connecting the cathode of 14+a to the operating power supply ■.
9, a slope signal generating circuit 14□. and the slope signal generating circuit 14□. output, i.e. diode 14+t, 14
A comparator circuit 14 receives the cathode output of 1e at one input, receives the reference voltage r4 at the other input, and generates a binary output.
□1, and a knot circuit 14□2 which receives the binary output of the comparison circuit 14□l.

The transmission power control mode under the above configuration will be explained below.

Now, transmitting/receiving station 4. ．． 16. The transmission level control circuit 8 of
Transmitting/receiving station4. ．． 16. Directing the radio waves from the antenna 10 or 12 to the opposing station at a relatively low transmission power level sufficient to raise the reception level to a predetermined value or higher in a state where the line loss distribution between the two stations is in a predetermined distribution. It is assumed that it is set to radiate. This is produced as follows.

When in such a setting, the frequency flf to transmitter 2
The IF input signal of IF amplifier 2. amplified by mixer 2
! and transmits the signal together with the transmitting local oscillator 2. A mixer 2□ receives a local oscillation signal of frequency f from
f + r).

This RF multiplied signal is amplified by the RF amplifier 2S, and its amplitude is attenuated by the analog signal from the transmission level control circuit 8 so that the transmission power level supplied to the antenna 10 becomes the above-mentioned level. is input to. Thus, radio waves with the transmission power level set to the above-mentioned level are radiated toward the opposing station to perform the required communication.

Opposing station 16. is received by the antenna 12 of the RF amplifier 1.
81 and is input to the RF multiplier signal mixer 182,
Receiving local oscillator 18 along with its RF multiplied signal. The mixer 18! which receives a local oscillation signal of frequency fllL"f?L from
AG signal is doubled and passed through the IF bandpass filter 184
It is input to the C amplifier 18s. The IF multiplied signal which is amplified and outputted as output 1 is inputted to a demodulator (not shown) and used for reproducing the transmission signal.

IF multiplied signal I output to output 2 of AGC amplifier 18s
It is amplified by F amplifiers 141.14□ and 144. These amplified IF multiplied signals pass through corresponding attenuators 14s and 14i and bandpass filters 147.149, are detected by corresponding detectors 1416.14+z, and spectrum component signals EL and EN corresponding to the bands are output, respectively. .

Each signal of the detectors 14I-, 14, z is sent to the corresponding comparator 1.
41. Reference voltage r preset in 141s
It is compared with l+r3. While the line loss distribution within the reception band is within the above-mentioned predetermined distribution, the detector 14
The +o and 14+z signals are generated based on the corresponding reference voltage to maintain the above-mentioned transmission power level, and the comparison circuit 1413.14ts outputs signals EL and EH accordingly. Therefore, the operational amplifier 14+t which receives the outputs of these comparison circuits 14° and 1414
The output of IEL EHl appears at the cathode of the diode 14+t, 14+s as the output of h. A corresponding binary level output, for example, when IEL EHI <ra, a high level "1" output is output from the comparator circuit 14g+, and the NOT circuit 14! ! The transmission power control command °“0°” is output from there. This command is for own station 1
6, is transmitted to the opposing station 4 via the transmitter 2 and antenna 12, and is applied to the transmission level control circuit 8 via the antenna lO1 receiver 18 of the opposing station 41. Thus,
The signal from circuit 8 maintains the transmission power level at a level that maintains line quality.

In such transmission and reception conditions, fading occurs.

If the line loss increases differently within the receiving band due to changes in weather, etc., the signal level received at the opposite station radiated at the set transmission power level as described above will decrease with a distribution corresponding to the increase. .

Therefore, as described above, the spectral component signal level output from the detectors 141 and 14.t also decreases accordingly. is the comparison circuit 14.3 or 14+s
It is output from As a result, the slope signal generation circuit 14! . A low level "0" signal is output from the NOT circuit 14, and a transmission power control command of "I" is output from the NOT circuit 14. This command is also transmitted to the opposite station in the same manner as described above. In this case, the signal level given from the receiver 18 to the transmission level control circuit 8 is a high level.
1". The transmission level control circuit 8 generates an analog signal to the variable attenuator 24 to reduce its attenuation, for example, to eliminate attenuation. As a result, the signal is radiated from the antenna 10. The transmission power level of the radio waves is increased to a level that can maintain the line quality, and the opposite station can receive the radio waves at a reception level that can maintain the line quality at a desired value.

The reduction in the transmit power level upon recovery of the line loss distribution occurs in the Feedback IIJ manner described above with the loss of the "1" transmit power control command.

Note that in the above embodiment, two
Although an example has been shown in which binary information "0°" or "1" is used, transmission power control using other binary information formats may be used, for example, a multi-level adjustment format.Changes in transmission power can be made using variable power This may be caused by adjusting the amplifier.Alternatively, the reduction in the transmit power level described above may be caused by a time delay.

(Effects of the Invention) As described above, according to the present invention, according to conventional knowledge, the time during which transmission must be performed under high transmission power is only a relatively small amount of time per year. According to the method of the present invention, which maintains the line quality by increasing the transmission power only for such a period of time, it is possible to significantly reduce the transmission power, reduce the degree of communication interference to other systems, and improve the radio waves to the area. We can also expect an increase in allocation.

[Brief explanation of drawings]

Figure 1 is a diagram showing the principle of the present invention; Figure 2 is a diagram showing an embodiment of the present invention; Figure 3 is a diagram showing the configuration of a transmitter and transmission level control circuit;
1 is a block diagram of a receiver, FIG. 5 is a tilt detection circuit diagram, and FIG. 6 is a block diagram of a conventional digital multiplex radio communication system. 1 to 5, 2 is a transmitter, 4 is a transmitting station (transmission/reception station 4.), 6 is a transmission power changing means (variable attenuator 2.), and 7 is a transmission level control means (transmission level control circuit). 8), 10.12 is a transmitting/receiving antenna, 13 is a transmission power control information output means (tilt detection circuit 14)
, 16 is a receiving station (transmission/reception station 16.), and 18 is a receiver.

Claims (1)

[Claims] In a wireless communication system in which a transmission signal is amplified by a transmitter (2) of a transmitting station (4) and radiated toward a receiving station (16) to perform a desired communication, the transmitting station (4) ) is provided in the transmitter (2) with a transmission power changing means (6) and a transmission level control means (7) for changing the transmission power; Transmission power control information output means (13) is connected to 18) and outputs transmission power control information based on the relationship that the relative value between spectrum components in the reception band exhibits with respect to a predetermined value, and the transmission power control information output means (13) is provided. adjusting the transmission power changing means (6) by the transmission level control means (7) responsive to transmission power control information sent from the means (13) via the wireless communication system; Characteristic transmission power control method.