JP2503868B2 - Transmission power control system - 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 and, more particularly, to a system using a coupler as a means for distributing an active side device and a standby side device in a set standby system receiving station.

[0002]

2. Description of the Related Art Generally, a receiving station used in a wireless communication system or the like is equipped with two receiving devices, and when one receiving device is out of order or maintenance is performed, a set standby system is used to switch to the other receiving device. (For example, Publishing Planning Center
Supervised by Moruichi Kuwahara Digital Microwave Communications 295-29
Section 7 Preliminary method (2) Set preliminary method). Further, in such a wireless communication system, a transmission power control system having means for controlling the transmission level of the opposite transmitter on the basis of the received input electric field information detected by the receiving station is used (for example, Japanese Patent Laid-Open No. Sho-SHO). 53-107214).

A conventional transmission power control system will be outlined below.

FIG. 4 shows an example of a system block diagram in that case.

The transmission output from the antenna 17 on the A station side is either the output on the working side transmitter 2 or the output on the standby side transmitter 2'selected by the microwave band switch 3, and is received by the antenna 18 on the B station. In this case, the working side transmitter 2 and the spare side transmitter 2'use the same frequency. The signal received by the antenna 18 is distributed by the coupler 9 to the receiver 10 on the working side and the receiver 10 'on the standby side. The receiver 10 on the working side receives a received signal having a reception level substantially the same as the input to the coupler 9 on the receiver 10 side. Received signals having a reception level including the loss of the coupler 9 are input to the respective '. Working receiver 1
0, the standby side receiver 10 'outputs the received input electric field information RSL1 and RSL2, which are the voltages corresponding to the received signals of the received level respectively, to the transmission power controller (RX) 13, and further the received signal is intermediate. After being converted into a frequency band and having a specified level, the working demodulator 11 and the protection demodulator 11 'demodulate the outputs of the working receiver 10 and the spare receiver 10', respectively, and output them to the switch 12. The switcher 12 selectively outputs whether to use the output of the working demodulator 11 or the output of the spare demodulator 11 ', and selects either the output of the working demodulator 11 or the output of the spare demodulator 11'. A first control signal indicating that is output to the transmission power controller (RX) 13.

FIG. 5 shows the transmission power controller (RX) 13.
Will be explained.

In the transmission power controller (RX) 13, the received input electric field information RSL1 and RSL2 are input to the switch 101. When the first control signal, which is a signal indicating that the output of the working demodulator 11 is being used, is input to the switch 101, it indicates that RSL1 is used and that the output of the standby demodulator 11 'is used. When the first control signal, which is a signal, is input, RSL2 is selected and output to the comparator 102. The comparator 102 compares the input switch output with a predetermined threshold value R _th and outputs it as a comparison result signal to the control circuit 103. The control circuit 103 converts the comparison result signal into a digital signal for transmission to the opposite station, and the working side modulator 14 and the spare side modulator 1 as transmission power control signals.
Output to 4 '. Working modulator 14, spare modulator 1
4'multiplexes the input main signal and the transmission power control signal, modulates them, and outputs them to the working transmitter 15 and the protection transmitter 15 ', respectively. Active transmitter 15, standby transmitter 1
Reference numeral 5'converts to a specified level and microwave band frequency for transmission to the opposite station (A station), and the microwave band switch 16
Respectively. In this case, the working side transmitter 15 and the spare side transmitter 15 'use the same frequency. The microwave band switching device 16 selects the output of the transmitter 15 on the working side or the output of the transmitter 15 'on the protection side, and sends it from the antenna 18 on the B station side to the antenna 17 on the opposite side. Antenna 17
The signal received at 1 is distributed by the coupler 4 to the working receiver 5 and the spare receiver 5 '. Working receiver 5,
The standby side receiver 5'converts the received signal received to an intermediate frequency band, and outputs it to the working side demodulator 6 and the standby side demodulator 6'after converting it to a prescribed level. Working demodulator 6, spare demodulator 6 '
Respectively demodulate the output of the working side receiver 5 and the output of the spare side receiver 5 ', separate the transmission power control signal multiplexed at the B station, and output it to the transmission power controller (TX) 8 for further demodulation. The signal is output to the switch 7. The switching device 7 selectively outputs whether to use the output of the working demodulator 6 or the output of the spare demodulator 6 ', and outputs the working demodulator 6'and the spare demodulator 6'.
A second control signal indicating which of the outputs is selected is output to the transmission power controller (TX) 8.

In the transmission power controller (TX) 8, when the second control signal, which is a signal indicating that the output of the active demodulator 6 is used, is input, the transmission power separated by the active demodulator 6 is input. The control signal is selected, the transmission power control voltage is output to the active side transmitter 2 and the standby side transmitter 2 ', and the second control signal which is a signal indicating that the output of the standby side demodulator 6'is being used is When input, the standby side demodulator 6'selects the separated transmission power control signal and outputs the transmission power control voltage to the active side transmitter 2 and the standby side transmitter 2 '. The transmitter 2 on the working side and the transmitter 2'on the standby side output an output level corresponding to the transmission power control voltage.

Next, the transmission power control voltage will be described.
The transmission power control voltage is determined by the transmission power control signal output from the transmission power controller (RX) 13 of the opposite station (station B).

The comparator 102 indicates a high value as the comparison result signal of the first level when any of the received input electric field information RSL1 and RSL2 selected by the switch 101 indicates a value lower than the threshold value R _th. At this time, the comparison result signal of the second level is output to the control circuit 103. The control circuit 103 is the first
Alternatively, the second level comparison result signal is converted into a corresponding level digital signal and output as a transmission power control signal. The transmission power signal is multiplexed with the main signal, which is the opposite station A.
The signal is transmitted to the station, separated from the main signal at the station A, and input to the transmission power control circuit (TX) 8. Transmission power control circuit (TX)
Reference numeral 8 outputs the first or second level transmission power control voltage to the working transmitter 2 and the backup transmitter 2 '. In the transmitter 2 on the working side and the transmitter 2'on the standby side, when the transmission power control voltage of the first level is input, the transmission output is controlled to the first predetermined output level and the transmission power control of the second level is performed. When the voltage is input, the second output level lower than the first output level is set.

As a method of distributing the received signal, it is possible to use HYB, but the output level of HYB suffers the same level loss with respect to the input, but in the case of the coupler, one output is lossy compared to HYB. However, the other output has almost no loss and a higher level output than that of HYB can be obtained. Therefore, when using the set spare method like this system, the coupler is used from the viewpoint of securing the system gain of the active side device.

[0012]

In this conventional transmission power control system, since the distribution of the set side active side equipment and the spare side equipment is performed by using the coupler, the reception level input to the active side receiver is Has almost no loss, but the reception level input to the receiver on the standby side is low by the loss of the coupler. The receiver on the working side and the receiver on the standby side each output the voltage reception input electric field information corresponding to the input reception level to the transmission power controller, which is selected by the switch in the transmission power controller and compared. The received input electric field information is compared with a predetermined threshold value by the instrument. When fading occurs due to failure of the active device and maintenance of the standby device, the received input electric field information is low by the loss of the coupler, and therefore the operation of increasing the transmission level by the opposite station also increases. For this reason, there is a problem that other lines are affected more than when the active device is used.

An object of the present invention is to provide a transmission power control system capable of reducing the influence of other lines when using a protection side device.

[0014]

According to the present invention, a received signal is input and the received signal is provided with a first output having a first level loss and a second level loss larger than the first level. It is used for a receiving station having a distributing means for distributing to a second output and a first and second receiving means for receiving or receiving and demodulating the first and second outputs, respectively, and controlling the transmission power. In the transmission power control system for controlling the transmission level of the opposite transmitter based on a signal, the first
And a first selecting means for selecting one of the outputs of the second receiving means and outputting a main signal, and for outputting a control signal indicating which of the outputs of the first and second receiving means is selected. First detecting means for detecting the level of the first output and outputting first received input electric field information, and second for detecting the level of the second output and output second received input electric field information Detecting means and the output of the first receiving means are selected by the first selecting means, the level of the first output is predetermined based on the first received input electric field information. 1 threshold value and the output of the second receiving means is selected by the second means, based on the second received input electric field information, the second output level and the first
Transmission power control means for generating a transmission power control signal according to a comparison result by comparing the transmission power control signal to the opposite transmitter. A transmission power control system characterized by the above is obtained.

[0015]

An embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a system block diagram of the present invention.

The transmission output from the antenna 17 on the A station side is either the output on the working side transmitter 2 or the output on the standby side transmitter 2'selected by the microwave band switch 3, and is received by the antenna 18 on the B station. . In this case, the active transmitter 2 and the standby transmitter 2 '
The frequencies used in are the same.

The signal received by the antenna 18 is distributed by the coupler 9 to the receiver 10 on the working side and the receiver 10 'on the standby side, and the receiver 10 on the working side receives a received signal having substantially the same reception level as the input to the coupler 9 on the standby side. Receiving signals of the receiving level including the loss of the coupler 9 are input to the receiver 10 '.

The receiver 10 on the working side and the receiver 10 'on the standby side output the received input electric field information RSL1 and RSL2, which are voltages corresponding to the received signals of the received level respectively, to the transmission power controller (RX) 13. Then, the received signal is converted to an intermediate frequency band to have a specified level and output to the working demodulator 11 and the standby demodulator 11 '. Working demodulator 1
1, the standby side demodulator 11 'demodulates the output of the working side receiver 10 and the output of the standby side receiver 10', respectively, and outputs them to the switching unit 12. The switch 12 selectively outputs whether to use the output of the demodulator 11 on the working side or the output of the demodulator 11 'on the standby side, and outputs either the output of the demodulator 11 on the working side or the output of the demodulator 11' on the standby side. The first control signal indicating whether or not it is selected is output to the transmission power controller (RX) 13.

FIG. 2 shows the transmission power controller (RX) 13.
Will be explained.

The transmission power controller (RX) 13 has a comparator 101 for comparing the working side received input electric field information RSL1 with a predetermined threshold value R _th 1, and a spare side received input electric field information RSL2. Threshold R _th
Threshold value R _th obtained by subtracting the loss of coupler 9 from 1
A comparator 101 'for comparing with 2 is provided.

The comparators 101 and 101 'use the comparison results as the first and second comparison result signals, respectively, to switch the switch 102.
Output to. In the switch 102, when the first control signal, which is a signal indicating that the output of the working demodulator 11 is being used, is input, the first comparison result signal is sent to the spare demodulator 1
When the first control signal, which is a signal indicating that the 1'output is being used, is input, the second comparison result signal is selected and output to the control circuit 103. The control circuit 103 is the switch 10
Either the first or second comparison result signal selected in 2 is converted into a digital signal for transmission to the opposite station, and is output to the working modulator 14 and the standby modulator 14 'as a transmission power control signal. To do.

The working side modulator 14 and the spare side modulator 14 'multiplex and modulate the input main signal and the transmission power control signal and output them to the working side transmitter 15 and the spare side transmitter 15', respectively. The transmitter 15 on the working side and the transmitter 15 'on the protection side convert the frequency to a specified level and a microwave band frequency for transmission to the opposite station (station A) and output the microwave band switch 16 respectively. In this case, the active transmitter 15 and the standby transmitter 1
The frequencies used in 5'are the same. The microwave band switching device 16 selects the output of the transmitter 15 on the working side or the output of the transmitter 15 'on the protection side, and sends it from the antenna 18 on the B station side to the antenna 17 on the opposite side.

The signal received by the antenna 17 is distributed by the coupler 4 to the working receiver 5 and the spare receiver 5 '. The receiver 5 on the working side and the receiver 5'on the standby side convert the received signal into an intermediate frequency band, and set it to a specified level and output it to the demodulator 6 on the working side and the demodulator 6'on the standby side.

The working demodulator 6 and the spare demodulator 6'demodulate the working receiver 5 output and the spare receiver 5'output, respectively, and separate the transmission power control signals multiplexed at the B station. ,
The signal is output to the transmission power controller (TX) 8, and the demodulated signal is output to the switch 7.

The switch 7 selectively outputs whether to use the output of the working demodulator 6 or the output of the standby demodulator 6 ', and outputs either the output of the working demodulator 6 or the output of the standby demodulator 6'. A second control signal indicating whether the transmission power controller (T
X) 8 is output. In the transmission power controller (TX) 8, when the second control signal which is a signal indicating that the output of the working demodulator 6 is used is input, the transmission power control signal separated by the working demodulator 6 is transmitted. A second control signal, which is a signal indicating that the selected transmission power control voltage is output to the active side transmitter 2 and the standby side transmitter 2 ', and the standby side demodulator 6'is being used, is input. In this case, the spare demodulator 6'selects the separated transmission power control signal and outputs the transmission power control voltage to the working transmitter 2 and the spare transmitter 2 '. Working transmitter 2,
The backup transmitter 2'provides an output level corresponding to the transmission power control voltage.

Next, the transmission power control voltage will be described.

The transmission power control voltage is determined by the transmission power control signal output from the transmission power controller (RX) 13 of the opposite station (station B).

The comparator 101 receives the received input electric field information RSL1.
To the comparator 102, the first comparison result signal of the first level is output when the value is lower than the threshold value R _th 1, and the first comparison result signal of the second level is output when the value is higher than the threshold value R _th 1. To do.
The comparator 101 'when the reception input electric-field information RSL2 indicates a value lower than the threshold value R _th 2 is the first of the second level when indicating the high value of the first comparison result signal of the first level The comparison result signal is output to the switch 102. Control circuit 10
3 converts the output of the switching device 102 of the first or second level into a digital signal of the corresponding level and outputs it as a transmission power control signal. The transmission power control signal is multiplexed with the main signal, transmitted to the opposite station, station A, separated from the main signal at station A, and input to the transmission power control circuit (TX) 8. The transmission power control circuit (TX) 8 outputs the transmission power control voltage of the first or second level to the active side transmitter 2 and the standby side transmitter 2 '.
In the transmitter 2 on the working side and the transmitter 2'on the standby side, when the transmission power control voltage of the first level is input, the transmission output is set to the predetermined first output level and the transmission power of the second level is set. When the control voltage is input, the second output level lower than the first output level is set. It goes without saying that the control circuit 103 can be omitted if the transmission power control circuit (RX) 13 outputs the outputs of the comparators 101 and 101 'as digital signals. Further, the transmission power controller (RX) 13 can be configured as shown in FIG. The transmission power controller (RX) 13 of FIG.
1 ', a comparator 102, and a control circuit 103, and when the first control signal shown as the output of the working demodulator 11 is input, the switcher 101 selects the received input electric field information RSL1,
The switch 101 ′ selects the threshold value R _th 1, and when the first control signal shown as the output of the standby demodulator 11 ′ is input, the switch 101 selects the received input electric field information RSL2,
The switch 101 'selects the threshold value R _th 2 and selects the comparator 102.
Respectively. The comparator 102 receives the received input electric field information RSL1 or RSL2 and the threshold value R _th.
1 or the threshold value R _th 2 is compared and output as a comparison result signal to the control circuit.

In this embodiment, as a means for transmitting information for transmission power control to the opposite transmission station, a method of digitizing the transmission power control signal, multiplexing it with the main signal and transmitting it to the opposite station has been described. It is also possible to frequency-modulate a carrier wave using a signal as a baseband signal separately from digital modulation for main signal transmission, and to transmit information.

[0031]

As described above, in the present invention, the comparator 101 for comparing the received input electric field information RSL1 with the predetermined threshold value R _th 1 in the transmission power controller (RX).
When, it is provided with the comparator 101 'and which compares the threshold R _th 2 minus the loss of the coupler from the threshold R _th 1 to a predetermined and reception input electric-field information RSL2, pre-side device Even if fading occurs by using, the time to receive fading is almost the same as when using the device on the working side. For this reason, there is an effect that the influence on other lines can be suppressed to almost the same as when the active device is used.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a transmission power control system according to the present invention.

2 is a block diagram showing an embodiment of a transmission power controller (RX) used in the transmission power control system shown in FIG.

FIG. 3 is a block diagram showing another embodiment of a transmission power controller (RX) used in the transmission power control system shown in FIG.

FIG. 4 is a block diagram showing a conventional transmission power control system.

5 is a block diagram showing a transmission power controller (RX) used in the transmission power control system shown in FIG.

[Explanation of symbols]

 1,1 'Modulator (MOD) [A station] 2,2' Transmitter (TX) [A station] 3 Microwave band SW (RX SW) [A station] 4 Coupler [A station] 5,5 'Reception Switch (RX) [A station] 6,6 'Demodulator (DEM) [A station] 7 Switch (SW) [A station] 8 Transmission power controller (TX ATPC) [A station] 9 Coupler [B station] 10, 10 'Receiver (RX) [B station] 11, 11' Demodulator (DEM) [B station] 12 Switch (SW) [B station] 13 Transmission power controller (ATPC RX) [B station] 14 , 14 'Modulator (MOD) [B station] 15,15' Transmitter (TX) [B station] 16 Microwave band SW (RX SW) [B station] 17 Antenna [A station] 18 Antenna [B station] 101, 101 'Comparator (switch) 102 Switch (comparator) 103 Control circuit

Claims (4)

(57) [Claims] 1. A distribution for receiving a received signal and distributing the received signal into a first output having a first level loss and a second output having a second level loss greater than the first level. And a first and second receiving means for receiving or receiving and demodulating the first and second outputs as inputs, and the transmission level of the opposite transmitter is based on the transmission power control signal. In the transmission power control system for controlling the above, either one of the outputs of the first and second receiving means is selected to output a main signal and the first signal is output.
And first selection means for outputting a control signal indicating which of the outputs of the second reception means is selected, and a first detection for detecting the level of the first output and outputting the first reception input electric field information. Means, second detecting means for detecting the level of the second output and outputting second received input electric field information, and output of the first receiving means are selected by the first selecting means. At this time, the level of the first output is compared with a predetermined first threshold value based on the first received input electric field information, and the output of the second receiving means is selected by the second means. The second output level is compared with the second threshold value lower than the first threshold value based on the second received input electric field information, and the transmission power control signal is generated according to the comparison result. Power control means and transmitting the transmission power control signal to the opposite transmitter Transmission power control system characterized by having a transmission means. 2. The transmission power control system according to claim 1, wherein the difference between the first threshold value and the second threshold value is the first level loss and the second level loss of the distribution means. A transmission power control system characterized by being equal to the difference between. 3. The transmission power control system according to claim 1 or 2, wherein the transmission power control means compares the first received input electric field information with the first threshold value. And second control means for comparing the second received input electric field information with the second threshold value, and the control signal with the outputs of the first and second comparison means and the control signal as inputs. Selects the output of the first comparing means when indicates the selection of the first receiving means, and selects the output of the second comparing means when the control signal indicates the selection of the second receiving means. 2. A transmission power control system having two selection means. 4. The transmission power control system according to claim 1, wherein the transmission power control means comprises:
When the control signal indicates selection of the first receiving means, the first reception input electric field information is selectively output, and when the control signal indicates selection of the second receiving means, the second reception input electric field information. When the control signal indicates the selection of the first receiving means, and when the control signal indicates the selection of the second receiving means. Transmission power, comprising: fourth selecting means for selectively outputting the second threshold value; and third comparing means for comparing the output of the third selecting means with the output of the fourth selecting means. Control system.