JPH03270515A - Transmission output control system in hot standby system - Google Patents

Abstract

PURPOSE:To attain the efficient line design at a low cost by controlling a standby transmission equipment so as to output a same output as that of an active transmission equipment when the active transmission equipment is faulty and controlling the standby transmission equipment so as to output a rated output higher than the output of the active transmission equipment in the normal state when a reception input of an opposite receiver is lowered abnormally. CONSTITUTION:A controller 3 being a CONT at a sender side 100 acts like controlling the changeover of a #1 transmission equipment (standby) with a device fault alarm from a #2 transmission equipment (active) and like controlling the output of the #1, #2 transmission equipments with a reception alarm representing an abnormally low reception input due to occurrence of fading coming from an opposite reception station 200 in common. The standby >=1 transmission equipment of the sender side 100 consists of a modulator MOD1 and a transmitter TX1, the active #2 transmission equipment comprises a modulator MOD2 and a transmitter TX2, and the system whose transmission output is decreased in the normal state is selected as the active system 2 and the system increasing the transmission output in the occurrence of fading is selected as the standby system #1. Since the transmission output of the standby system #1 is increased in the occurrence of fading, a variable attenuator 21 whose attenuation is decreased by a control voltage V being an output of the controller 3 being the CONT is inserted to an intermediate frequency stage between the modulator MOD1 and the transmitter TX1 of the standby #1 transmission equipment.

Description

[Detailed Description of the Invention] [Summary] A digital radio system is comprised of two systems of transmitting equipment and receiving equipment, and one of the transmitting equipment and receiving equipment is always used. Regarding the hot standby backup method, in which when one system fails, the system switches to the other backup system, and in the event of a failure of the active transmitter or a drop in reception input, the transmitter side switches to the output of the backup transmitter. Even though.

It does not use an expensive high-frequency switch, and it uses two controllers in common: a controller that drives the high-frequency switch and a controller that changes the output size of the standby transmitter, so it can be connected to other lines at low cost. The purpose of this method is to provide a transmission output control method for the hot standby backup method that allows for an overall efficient circuit design with less interference to a directional coupler C, which couples the signals with each other, and an attenuator ATT, which is controlled to vary the output of the spare transmitter.
The output of the standby transmitter is normally controlled to a value lower than its rated output by the output of one controller C0NT, and it transmits a value lower than the output of the active transmitter. In the event of a failure, the output is controlled to be the same as the output of the currently used transmitter, and when the receiving input of the opposing receiver is abnormally low, the rated output is controlled to a value higher than the output of the normally used transmitter. Configure it so that it is sent.

[Industrial application field]

The present invention provides a delta system consisting of two systems of transmitting equipment and receiving equipment.
In a digital wireless communication system, one system is selected on the transmitting side by a high-frequency switch of the transmitting output, and on the receiving side by a low-frequency switch of the receiving output, and the transmitting device and receiving device of one of the two systems are always selected. However, when one of the active systems on the transmitting and receiving sides fails, the hot standby system is switched to the other backup system. Control method [Prior art] In the conventional hot standby backup method in digital wireless communication, as shown in FIG. Intermediate frequency modulation signal IF with MOD I,
The transmission output P1RF of the first system transmitter, which is converted into a high frequency radio signal RF by the transmitter TX, and the second system transmitter, which is similarly converted by the modulator MOD1 and the transmitter TX2 of the second system. The same radio frequency RF.

The transmission output PtRF is selected by the high frequency switch S''Aav and transmitted.

On the receiving side 200, the receiving input of the same radio frequency 12F is branched into two by the hybrid HI1RF, and the # receiver RX
, converts it into an intermediate frequency signal IF, and sends it to the demodulator DEM l
The reception output BB+ of the first system receiving device which is converted to a low frequency baseband by the #2 receiver Rxz and the demodulator DE
The configuration is such that the received output BB2 of the second system receiving device, which is similarly converted and outputted at Mz, is selected and outputted by the low frequency switch S-0, and normally the received output BB2 of the second system receiving device of IL#2 is output. One of the systems, for example, the transmitting device and receiving device #2, is used, and the transmitting side 100 is the modulator MOD+, MOD of the transmitting device of the second system.

By generating a control voltage ■1 in the controller C0NT+ and driving the high frequency switch S-0 due to a transmission alarm of a failure in the transmitter TX1, TX, or by fading from the opposite receiving station in the controller C0NTz. The control voltage v2 is generated by an alarm of an abnormal drop in the receiving input to drive the variable attenuators ATTO and ATTz and transmit the transmitters TX1 and TX2.
By controlling the attenuation for each input IF of the current! ! Transmission is performed by switching from output P2RF of transmitter #2 to output P1RF of backup #1 transmitter. Then, the receiving side 200 switches and outputs the output BB2 of the 12 active receiving devices to the receiving output BBI of the backup # using the low frequency switch S-0. And the sending side 100 and the receiving side 2
Considering that the reception input RFR of the receiving device on the receiving side 200 decreases due to fading that occurs approximately 0.01% per year on the spatial transmission path between 00 and 00, the $
1. #2 transmitter output P1RFI' Pzxr.

The quality of the received signal on the receiving side 200 is increased by, for example, 30 to 40 dB higher than the required value based on the quality of the received signal on the receiving side 200.
.

s2 receiver RX1, RX! Receive input RF+ with high value
I am trying to receive t. Actually, #. of the sending side 100. 12 (7) Modulator MOD+, MODz of transmitter
Variable attenuators ATTO, ATTz are provided in the intermediate frequency IF stage between the transmitters TX, TX, or in the radio frequency RP stage of the outputs of the transmitters TX+, TXz, and the reception input RF, l from the opposite receiving station is Controlled by controller C0NT2 due to alarm of drop! A lightning voltage 2 is generated, and the variable attenuator ATTO,
Controls ATTz to output the transmitting device P1RF+PtR
It was controlling W.

[Problem to be solved by the invention]

As mentioned above, the transmission output control method in the conventional hot standby backup method takes into consideration the decrease in the receiving input RF of the receiver due to the occurrence of fading for a short time in the spatial transmission path between the transmitting side 100 and the receiving side 200. Then, the transmitter always transmits with the transmission output P1RFI PZIF higher than the required value based on the quality of the reception output, and the receivers #L and #2 on the reception side receive the reception input RF with a high value. As a result, there was a problem in that interference noise to other microwave lines increased, hindering efficient line design as a whole.

Also, the transmission output of the 1tL #2 transmitter is P1RF+ pi
A high frequency switch S tag that switches the er, and a modulator MO
Intermediate frequency IF stage between D+5M0Dz and transmitters TX1, TX2 or radio frequency RP of output of transmitters TXI, TXt
The variable attenuators ATTO and ATTz inserted in each stage are expensive, and the controller C that drives the high frequency switch ShF is expensive.
0NT, and a controller C0NTz for driving the variable attenuators ATT+ and ^TT2, there is a problem in that the cost of the device increases. SUMMARY OF THE INVENTION An object of the present invention is to provide a transmission output control system in a hot standby backup system that is low cost, has little interference with other lines, and enables an overall efficient line design.

[Means to solve the problem]

This problem is solved because digital wireless communication generally has a strong resistance to interference noise, and even if the power ratio of the main signal and interference signal exceeds the value (for example, in 4-phase PSK, there may be interference noise of about -30 dB or more). For example, by focusing on the fact that there is no problem in the transmission of the main signal and that the transmitters TX1 and TX2 of ##2 output the same signal at the same frequency, the following principle diagram is shown in Fig. 1: $1, #2 transmitter output P1RF+ P2R
Instead of the high frequency switch S-□ selecting F, the arm 1. I
a directional coupler (D, C) 1 that couples the transmission outputs PBp+PZIF of 2 with a constant attenuation amount, and an attenuator (D, C) 1 that is controlled to vary the output P1RF of the transmitter of the spare 01).
ATTO) 2+ and one controller (CONT) 3 are provided, and the variable attenuator (ATT, ) 21 is controlled by the control voltage V of the output of the controller (CONT) 3 to create a backup #I transmitter. The output PI1RF of the active I2 transmitter is normally controlled to a value lower than its rated output and lower than the output P It is controlled to be the same value as the output pzgr and transmitted, and when the receiving input of the opposite receiving station is abnormally low, the active #
The output of the transmitting device P2. Rated output P with a value higher than IF
This problem is solved by the transmission output control method of the present invention, which is configured to control and transmit data to 1RF.

In order to reduce interference with other lines, the output of the active 1t2 transmitter during normal operation should be
When the output of the transmitting device stops and the receiving input decreases due to fading of the opposite receiving station 200, the working system #2 is switched to the backup system #2, and the working system is no longer needed. The output stop of the 12 transmitting devices is caused by the transmitter TX1 of the transmitting device,
Local oscillators TLO, TlO2 for frequency conversion of TXz
or stop the power supply to the local oscillator, or stop the variable attenuator 2 in the front stage of the transmitters TX1 and TX2.
Do this in 12□.

Detection of reception failure due to fading on the receiving side 200 is performed by receivers RX1 and RX! of #2. This is done by detecting the occurrence of a spectral slope within the band of the output intermediate frequency signal IFR, or the occurrence of a dip in the level drop of a plurality of frequencies.

[Effect]

One controller (CONT) 3 provided on the transmitting side 100 is
The variable attenuator 2 of the standby system #1 is controlled by the control voltage V of its output.
．． By changing the amount of attenuation of the output PI of the backup #1 transmitter,
1RF is always set at a constant value 2α from its rated output (α is the allowable value of interference noise determined by the digital modulation format,
The output P2RF of the current transmitting device #2 is controlled to a lower value by α (the amount by which the reception input decreases than the normal value due to fading), and the output of the current transmitter #2 is transmitted through the directional coupler 1 to the current transmitter #2. Should it be transmitted to the receiving side 200 together with the output PzlF of the transmitting device No. 2?

Output is cut off when the transmitting local oscillator TLO stops operating, but when a transmitting alarm is input when the active #2 transmitting device fails,
It transmits by controlling it to the same value as the output P2RF of the current transmitting device, and when a reception alarm is input when the reception input of the opposite receiving station is abnormally low, the output P□ of the constantly working I2 transmitting device is
, the rated output PI1RF is controlled by 2α higher than ,
The signal is transmitted to the receiving side 200 via the directional coupler 1.

Therefore, the transmission output control method in the hot standby backup method of the present invention is based on the conventional expensive high frequency switch 5WRF.
The cost problem is solved because an inexpensive directional coupler is used instead, and the output P2RF of the current I2 transmitter is a normal one without fading due to the decrease α in the receiving input of the receiving side 200. At this time, the receiving device tl, #2 transmits an output to the receiving side 200 via the directional coupler 1 with the attenuation coupling amount α, so that the receiving input RF+i necessary for maintaining the quality of the receiving output is obtained. At that time, the output P1RF of the 1,000@#1 transmitting device is transmitted through a variable attenuator 2. whose attenuation amount is controlled by the control voltage V of the output of one controller 3. Therefore, the output is controlled to be a constant value 2α lower than its rated output, and the output, which is α lower than the output P21F of the active #2 transmitting device, is transmitted to the receiving side 200 via the directional coupler 1. Otherwise, the output will be cut off. Therefore, the problem is solved because unnecessary output is not transmitted and interference noise given to other lines is not increased.

〔Example〕

The principle diagram in FIG. 1 is a block diagram showing the configuration of a transmission output control method in a hot standby backup method according to an embodiment of the present invention, and corresponds to the first to fifth embodiments of the present invention. FIG. 2 is a detailed explanatory diagram of the fifth aspect of the present invention.

In FIG. 1, on the transmitting side 100, instead of the high frequency switch 5WRFO of the output of the conventional transmitting device, the output P2RF of the transmitting device of the working system f2 is changed by a certain amount α from the output P1RF of the transmitting device of the protection system #l. A directional coupler 1 that performs attenuation and coupling is used, and the coupling attenuation amount α is set to 4-phase PSK.
Assuming that the allowable value of interference noise for the modulated signal is 30 dB, the output PZ1RF of the active #2 transmitter is
The output of the transmitting device P1RF is -30 dB,
There is no problem even if both the active system #2 and the backup system #1 coexist. Therefore, there is no problem even if the transmitter TX2 of the active system #2 and the transmitter @TK of the protection system #1 transmit at the same time.

In addition, the controller 3 on the transmitting side 100 controls the switching to the preliminary III transmitter in response to a device failure alarm from the active II transmitter as - C0NT, and the opposite receiving station 2
Since this function also serves as the output control of each transmitter ##2 due to the reception alarm indicating an abnormal decrease in the reception input due to the occurrence of fading from 00, there is no problem of high cost of the device. For this purpose, on the transmitting side 100, the backup #1 transmitter is configured with a modulator MODr and a transmitter #TX, and the active #2 transmitter is configured with a modulator MOD2 and a transmitter TX2. The system that lowers the transmission output when fading occurs is set as the active system #2, and the system that increases the transmission output when fading occurs is set as the protection system #1. And in order to increase the transmission output of the backup system #l when fading occurs.

A variable attenuator 21 that reduces the amount of attenuation using the control voltage V of the output of C0NT of the controller 3 is inserted in the intermediate frequency stage between the modulator MOD of the transmitter of the preliminary Ill and the transmitter TX. Therefore, the equipment failure alarm input to C0NT of the controller 3 on the transmitting side 100 is only from the active system I2, and the control of the output of the transmitting device to the receiving side 200 is only for the backup system #1. , the circuit is simplified.

Then, when the system in use during normal operation is the active system #2, the output of the transmitting device of the unnecessary protection system #1 is stopped, and when fading occurs, the active system +! After switching from TX1.2 to standby system #2, the output of the transmitting device for the currently used fundamental tone 2, which is no longer needed, is stopped due to transmission #TX1. TX! Either stop the oscillation of the local oscillators TLO+, TL (h) for frequency conversion, or stop the power supply to the local oscillators, or stop the transmitter TX.
Since this is performed by the variable attenuator 2°2□ in the preceding stage of I and TX2, interference noise to other lines is reduced.

Detection of reception failure due to the occurrence of fading on the receiving side 200 is performed by the receiver RX of ##2 as shown in the explanatory diagram of FIG.
1. Occurrence of a slope in the selective spectrum extracted at the center frequency f O + negative side frequency f - and positive side frequency f in the band of the intermediate frequency signal IFl of the output of RXZ, or occurrence of a dip in level reduction for multiple frequencies By detecting , it is possible to easily perform detection corresponding to selective fading.

〔Effect of the invention〕

As explained above, according to the present invention, (1) the level of interference waves to other lines during normal operation can be significantly reduced, so that the digital radio line can be used effectively in terms of area. - Since the transmission output control and the transmission switching sequence in the event of a device failure on the transmitting side are simple, the reliability of the line can be improved. ■Since a directional coupler, which is a passive element, is used for the transmission switch,
The reliability of equipment can be improved. (2) Since a circuit capable of selective fading detection is used for fading detection at the receiving end, effects such as improved line reliability can be obtained.

(α) The occurrence of Butram's I-Koroma 4 Normal Hue:,;〉When

[Brief explanation of drawings]

Fig. 1 is a principle diagram showing the basic configuration of the transmission output control method in the hot standby backup method of the present invention, Fig. 2 is an explanatory diagram of the operation of fading generation in the embodiment of the present invention, and Fig. 3 is a conventional hot standby method. FIG. 2 is a block diagram of a backup method. In the figure, 1 is a directional coupler, 2I is a variable attenuation diagram for explaining the gravitational operation of the method for detecting the occurrence of a phase phase during normal operation of the present invention.

Claims (1)

[Scope of Claims] A digital device comprising transmitting devices and receiving devices of two systems (#1, #2) and always using the transmitting device and receiving device of one of the two systems (#2). The wireless system is the transmitter (
In the hot standby protection method, when the current system (#2) fails on the receiving side (200) or the receiving side (200), the system switches to the other protection system (#1).
) and a directional coupler (1) that couples the outputs (P_1_R_F, P_2_R_F) of the respective devices to the output terminals of the backup (#1) transmitter with a certain amount of attenuation; ) is provided with a variable attenuator (2_1) that changes the output (P_1_R_F) of the transmitter of The output (P) of the currently used (#2) transmitter is controlled to a value lower than the output.
_2_R_F), but the current value (#2)
When a transmitting device fails, the output of the currently used transmitting device (P_
2_R_F), and when the reception input of the opposite receiving station is abnormally low, the output is controlled to the rated output (P_1_R_F), which is higher than the output (P_2_R_F) of the transmitter in normal use (#2). A transmission output control method in a hot standby backup method, which is characterized in that the transmission power is transmitted after 2. In the hot standby backup method, the active (1
2) A controller that switches the output of the transmitting device to the output of the backup transmitter (#1) in the event of a failure of the device, and a controller that switches the output of the transmitter (#1) to the output of the backup transmitter (#1) when there is a failure in the device, and a controller that switches the output of the transmitter (#1) to the output of the backup transmitter (#1) when the output of the transmitter (#1) is switched to the output of the backup transmitter (#1) when the output of the transmitter (#2) is switched to the output of the backup transmitter (#1) when the receiving input of the receiver opposite the active transmitter (#2) decreases abnormally. A transmission output switching system characterized in that the controller (3) is the same as the controller that switches the output (P_1_R_F) of the transmitter (#1) to a value higher than the output (P_2_R_F) of the always-current transmitter. . 3. In the transmission output control method in the hot standby backup method, two systems (#1,
#2) transmitter output ((P_1_R_F, P_2_
A transmission method for a digital radio system characterized by simultaneously transmitting R_F) with a certain level difference. 4. In the transmission output control method in the hot standby backup method, the output of the backup (#1) transmitter is stopped when the output of the active (#2) transmitter is being transmitted during normal operation. When switching from the working system (#2) to the backup system (#1) when the reception input of the receiving station abnormally decreases, the working system (#1) is no longer needed.
#2) If the output of the transmitter is stopped, the transmitter (TX
_1, TX_2) local oscillator (TL0) for frequency conversion
_1, TL0_2), or stop the power supply to the local oscillator, or stop the oscillation of the transmitter (TX_1, TX
By providing sufficient attenuation to the input signal to _2),
A transmission output cutoff method characterized in that the output of the transmitter is cut off. 5. In the hot standby backup method, two systems (#1, #2
) receiver (RX_1, RX_2) output signal (IF_
A method for detecting fading occurrence, characterized in that it is detected by the occurrence of a slope in the spectrum within the band R) or by the occurrence of a dip in level reduction for a plurality of frequencies.