JP4670673B2 - Transmission power control apparatus, method and program - Google Patents

Description

  The present invention relates to a transmission power control apparatus and the like in a hot standby system used for microwave digital communication, for example.

  For example, in microwave digital communication, a hot standby system is used in which communication devices are multiplexed to improve reliability (Patent Document 1). In the hot standby method, two systems of transmission / reception units having the same configuration are prepared, that is, the active system and the standby system, and signals are normally processed only by the active system while operating both the active system and the standby system simultaneously. As a result, when a failure occurs in the active system, the processing can be immediately taken over by the standby system. As an example of such a hot standby system, a wireless communication system (hereinafter referred to as “first prior art”) described in Patent Document 1 will be described with reference to FIG.

  The baseband signal applied to the input terminal 51 of the transmission terminal 50 is branched by the hybrid 52 and output to the active and standby baseband processing sections 53a and 53b, and the modulation sections 54a and 54b and the transmission section 55a, respectively. , 55b. The output signals of the transmission units 55a and 55b are transmitted from the antenna 59 through the switch 57 and the duplexer 58. The output power of the transmission units 55a and 55b is detected by the detectors 56a and 56b, respectively. The control circuit 61 controls the switch 57.

  On the other hand, the signal received by the antenna 79 of the receiving end 70 is branched into two by the hybrid 80 via the duplexer 78, and is input to the receiving units 71a and 71b of the active system and the standby system, and the demodulating units 72a and 71b, respectively. 72b and baseband processing units 73a and 73b. The output signals of the baseband processing units 73a and 73b are output from the output terminal 75 via the switch 74 for switching between the active system and the standby system. In addition, the monitoring circuit 76 monitors the continuity of the transmission signal based on the output signals of the baseband processing units 73a and 73b. Further, the transmitting device 77 sends a signal through the reverse line from the receiving end 70 to the transmitting end 50, and the receiving device 60 receives the signal at the receiving end 50 through the reverse line.

  Here, the detection results of both the active and standby detectors 56a and 56b at the transmission end 50 indicate that the output power of the transmission units 55a and 55b is normal, and both the modulation units 54a. , 54b are in a state where no alarm is issued, but an abnormality has occurred in the transmission signal due to a failure of the active modulation unit 54a. This abnormality of the transmission signal is called silent failure (silent failure). In this state, no abnormality can be detected at the transmitting end 50, so that the switch 57 still holds the active system.

  At this time, at the receiving end 70, the monitoring circuit 76 detects that an abnormality has occurred in both the active and standby signals. If the device at the transmitting end 50 is faulty, this state continues for a long time. Therefore, when the monitoring circuit 76 detects that the signal abnormality continues beyond a predetermined time length, the monitoring circuit 76 transmits the information from the transmitting device 77 to the receiving device 60 of the transmitting end 50 through the reverse line. When this signal abnormality continuation information is given from the receiving device 60, the control circuit 61 controls the switch 57 accordingly to switch the connection to the standby transmission unit 55b. As a result, the transmission end 50 starts transmitting a normal signal output from the standby transmission unit 55 b toward the reception end 70.

  As described above, when the reception end 70 transmits information indicating that the reception signals of both the active system and the standby system are abnormal to the transmission end 50 through the reverse line, a silent failure occurs at the transmission end 50. Even in such a case, the transmission / reception system 50 can be switched between the active system and the standby system.

  By the way, similarly, in microwave digital communication, a transmission power control (ATPC: Automatic Transmitting Power Control) method for minimizing interference and reducing power consumption is used (Patent Document 2). As an example of such a transmission power control system, a radio communication system (hereinafter referred to as “second prior art”) described in Patent Document 2 will be described with reference to FIG.

  The transmitter 91 on the A station 90A side sends a signal S00 to the B station 90B side through a wireless line from the A station 90A to the B station 90B. The receiver 92 on the B station 90B side receives the signal S00, outputs reception input level information S01 indicating the reception input level to the transmission power controller 93, and receives the received signal S00 as a BER (Bit Error Rate) detector. Output to 94.

  When receiving the signal S00, the BER detector 94 detects the received signal line quality based on the signal S00, and outputs the line quality deterioration alarm information S03 when detecting a BER worse than a predetermined BER. The determination device 95 includes a timer capable of setting the time. When the BER detector 94 continuously outputs the line quality deterioration alarm information S03 for a time longer than the set time of the timer, the device failure information S04 is transmitted. Output to the power controller 93.

  Normally, the transmission power controller 93 controls the transmission output level of the transmitter 91 through a reverse route line from the B station 90B to the A station 90A based on the reception input level information S01 from the receiver 92. For example, when the reception input level represented by the reception input level information S01 is low, a transmission output level control signal S02 for increasing the transmission output level is output to the transmitter 91, and the transmission output level is increased. As a result, even when fading occurs, the transmission output level is always maintained at an appropriate level, so that signal deterioration due to a decrease in reception input level is prevented. Note that fading means that the radio wave reception level fluctuates with the movement of a wireless station or the passage of time in wireless communication or broadcasting.

  However, when the determiner 95 outputs the device failure information S04, the transmission power controller 93 does not cause fading but causes a device failure even when the reception input level information S01 indicates a decrease in the reception input level. The transmission output level control signal S02 is immediately output and the transmission output level of the transmitter 91 is lowered to the minimum value.

  According to such a transmission power control method, it is possible to accurately determine a device failure and lower the transmission output level, so that it is not erroneously determined to be fading and increase the transmission output level. Can be prevented.

Japanese Patent Laid-Open No. 63-283236 “Preliminary Device Switching Method” Japanese Patent Application Laid-Open No. 5-191300 "Transmission power control method for wireless device"

  However, when the first conventional technology and the second conventional technology described above are combined, the silent-fair countermeasures control and the transmission power control are executed independently, resulting in the following problems.

  The first problem is that when a silent failure occurs, it cannot be relieved. The reason for this is that transmission power control minimizes transmission power by determining silent failure as a device failure. This is because it does not change. Conversely, even if switching to the standby system first as a countermeasure against silent failure, the reception side alarm that occurs at the time of switching is included in the condition of equipment failure in the transmission power control, so the transmission power is minimized after switching. .

  The second problem is that the transmission efficiency of the auxiliary signal is poor because the silent failure countermeasure signal and the transmission power control signal are transmitted independently.

  Therefore, the main object of the present invention is to enable normal operation of control for countermeasure against silent failure and control for minimizing interference in a configuration employing a hot standby method and a transmission power control method. Another object is to provide a transmission power control device and the like.

  The transmission power control apparatus according to the present invention includes failure signal input means, transmission switching signal output means, and transmission output minimized signal output means. The failure signal input means inputs a failure signal related to the transmitter from the receiver facing the hot standby transmitter having the active transmission unit and the standby transmission unit. The transmission switching signal output means outputs a transmission switching signal for switching from the active transmission unit to the standby transmission unit when the failure signal input unit inputs the failure signal. The transmission output minimizing signal output means transmits the transmission of the standby system transmission unit if a failure signal is input by the failure signal input means even after a lapse of a certain time after the transmission switching signal is output by the transmission switching signal output means. A transmission output minimizing signal that minimizes the output level is output.

  As described above, in the technology simply combining the first conventional technique and the second conventional technique, when a failure signal is input from the receiver, a transmission switching signal for switching from the active transmission unit to the standby transmission unit is output, A transmission output minimization signal that minimizes the transmission output level of the standby transmission unit is output. For this reason, even if switching to the standby transmission unit as a countermeasure against silent failure, the transmission output level is minimized, and as a result, silent failure cannot be relieved.

  On the other hand, in the present invention, when a failure signal is input from the receiver, a transmission switching signal for switching from the active transmission unit to the standby transmission unit is output and the system waits for a certain period of time. If the failure signal is not input during this fixed time, the cause of the failure is a silent failure, and the silent failure is relieved. On the other hand, if a failure signal is input even after a certain period of time has passed, this means that the failure has not been recovered even when switching to the standby transmission unit, and adjacent interference will occur even if transmission is continued further. Therefore, the transmission output level of the standby transmission unit is minimized.

  Further, the failure signal input means, the transmission switching signal output means, and the transmission output minimization signal output means may be provided in the transmitter. Further, the transmitter may be a first transceiver and the receiver may be a second transceiver.

  The transmission power control method according to the present invention includes a first step, a second step, and a third step. In the first step, a failure signal related to a transmitter is input from a receiver facing a hot standby transmitter having an active transmission unit and a standby transmission unit. In the second step, when a failure signal is input, a transmission switching signal for switching from the active transmission unit to the standby transmission unit is output. In the third step, a transmission output minimizing signal for minimizing the transmission output level of the standby transmission unit is output if a failure signal is input even if a fixed time has elapsed after the transmission switching signal is output. The transmission power control method according to the present invention also has the same effect as the transmission power control apparatus according to the present invention.

  The transmission power control program according to the present invention is for causing a computer to function as a failure signal input unit, a transmission switching signal output unit, and a transmission output minimization signal output unit. The failure signal input means inputs a failure signal related to the transmitter from the receiver facing the hot standby transmitter having the active transmission unit and the standby transmission unit. The transmission switching signal output means outputs a transmission switching signal for switching from the active transmission unit to the standby transmission unit when the failure signal input unit inputs the failure signal. The transmission output minimizing signal output means transmits the transmission of the standby system transmission unit if a failure signal is input by the failure signal input means even after a lapse of a certain time after the transmission switching signal is output by the transmission switching signal output means. A transmission output minimizing signal that minimizes the output level is output. The transmission power control program according to the present invention also has the same effect as the transmission power control apparatus according to the present invention.

  The present invention can be rephrased as follows. In the transmission switching method using transmission power control, a control circuit for generating a transmission power control signal on the transmission side and a transmission switching control signal is mounted, and the transmission output transmitted from the opposite (receiving side) station is installed in this control circuit. A control signal is input. On the receiving side, a transmission power control board for generating a transmission output control signal is mounted, and the transmission power control board inputs reception input level information and channel quality information and outputs a transmission control signal. This transmission control signal is input to the transmission board to be sent to the opposite (transmission side) station.

  According to the present invention, when a failure signal related to the transmitter is input from the opposite receiver, a transmission switching signal for switching from the active transmission unit to the standby transmission unit is output, and the failure signal is input even after a predetermined time has elapsed. If this is done, the control for minimizing the interference can be executed after executing the control for the silent failure by outputting the transmission output minimizing signal that minimizes the transmission output level. In the configuration adopting the transmission power control method and the transmission power control method, it is possible to normally operate the control for countermeasure against silent failure and the control for minimizing the interference.

  In other words, the first effect is that in the hot standby system using transmission power control, when a silent failure occurs, even if the transmission output should be minimized in consideration of the interference, the silent failure is reduced. It can be rescued. The reason for this is that the contradiction when the transmission switching control and the transmission output level minimization control are independently executed on the transmission side is judged using one transmission output level control signal on the reception side and each control is executed. This is because the problem is solved. The second effect is that the transmission efficiency of the auxiliary signal is improved because the transmission switching control and the transmission output level minimization control are executed on the transmission side using only the transmission power control signal. The third effect is that the configuration is simple because the control signal generation circuit on the receiving side only needs to be used for transmission power control.

  FIG. 1 is a block diagram showing an embodiment of a transmission power control apparatus according to the present invention. FIG. 2 is a block diagram illustrating a first example of a wireless communication system including the transmission power control apparatus of FIG. FIG. 3 is a flowchart showing an example of the operation of the transmission power control apparatus of FIG. Hereinafter, description will be given based on these drawings.

  As shown in FIGS. 1 and 2, the transmission power control apparatus according to the present embodiment is realized inside the control circuit 15 as a failure signal input unit 151, a transmission switching signal output unit 152, and a transmission output minimized signal output unit 153. Has been. The failure signal input means 151 is transmitted from the transmitter / receiver 20 facing the hot standby transmitter / receiver 10 having the active transmitter (transmitter 11a and mute circuit 12a) and the standby transmitter (transmitter 11b and mute circuit 12b). Then, a failure signal (transmission output level control signal S6) related to the transceiver 10 is input. The transmission switching signal output unit 152 outputs a transmission switching signal (transmission mute signals S8a and S8b) for switching from the active transmission unit to the standby transmission unit when the failure signal input unit 151 receives a failure signal. The transmission output minimizing signal output means 153 is a standby system transmission if a failure signal is input by the failure signal input means 151 even after a predetermined time has elapsed since the transmission switching signal was output by the transmission switching signal output means 152. A transmission output minimizing signal (transmission output control signals S7a, S7b) for minimizing the transmission output level of the unit is output.

  The control circuit 15 operates as follows. First, when a failure signal is input from the transceiver 20, a transmission switching signal for switching from the active transmission unit to the standby transmission unit is output, and the system waits for a certain time. If the failure signal is not input during this fixed time, the cause of the failure is a silent failure, and the silent failure is relieved. On the other hand, if a failure signal is input even after a certain period of time has passed, this means that the failure has not been recovered even when switching to the standby transmission unit, and adjacent interference will occur even if transmission is continued further. Therefore, the transmission output level of the standby transmission unit is minimized.

  The failure signal input means 151, the transmission switching signal output means 152, and the transmission output minimization signal output means 153 may be realized by a microcomputer included in the control circuit 15 and its program, or by hardware such as an IC. It may be realized.

  Next, a more detailed description will be given based on FIG. The transceiver 10 includes transmission boards 11a and 11b, mute circuits 12a and 12b, reception boards 13a and 13b, a switching circuit 14, a control circuit 15, duplexers 16a and 16b, antennas 17a and 17b, and the like. The transmission board 11a and the mute circuit 12a are active transmission parts, and the transmission board 11b and the mute circuit 12b are standby transmission parts. On the contrary, the transmission board 11a and the mute circuit 12a may be a standby transmission part, and the transmission board 11b and the mute circuit 12b may be an active transmission part. The transceiver 20 includes transmission boards 21a and 21b, mute circuits 22a and 22b, reception boards 23a and 23b, BER detection circuits 24a and 24b, transmission power control board 25, duplexers 26a and 26b, antennas 27a and 27b, and branch circuits. It consists of 28 etc.

  On the transceiver 20 side, the transmission output level control signals S4a and S4b are transmitted to the opposing transceiver 10 using only the transmission power control panel 25. On the transceiver 10 side, only the control circuit 15 is used to output transmission output control signals S7a, S7b and transmission switching signals S8a, S8b based on the input transmission output level control signal S6, and transmission boards 11a, 11b and The mute circuits 12a and 12b are controlled.

  In other words, the control circuit 15 on the transceiver 10 side receives the transmission output level control signal S6 and outputs the transmission output control signals S7a and S7b and the transmission mute signals S8a and S8b from the condition of the transmission output level control signal S6. Thus, transmission control by the transmission boards 11a and 11b and transmission switching by the mute circuits 12a and 12b are executed. On the other hand, the transmission power control board 25 on the transceiver 20 side receives the reception input level information S1a and S1b and the line quality degradation information S2a and S2b, and outputs a transmission output level control signal S3. The transmission output level control signal S3 is input to the transmission boards 21a and 21b for the purpose of sending the transmission control information to the opposing transceiver 10.

  Next, the operation of the entire wireless communication system in FIG. 2 will be described. First, in the transceiver 20, the level detection signals received via the antennas 27a and 27b, the duplexers 26a and 26b, and the reception boards 23a and 23b are input to the transmission power control board 25 as reception input level information S1a and S1b, respectively. Is done.

  The transmission power control panel 25 outputs a transmission output up signal as a transmission output level control signal S3 when the higher one of the reception input level information S1a and S1b is lower than the first lower limit value. In this case, when the reception input level continuously decreases as in normal fading, the transmission output up signal is continuously generated until the second lower limit value is reached. If the reception input level continues to decrease, the BER detection circuits 24a and 24b determine that the line is disconnected, and output line quality deterioration information S2a and S2b to the transmission power control panel 25.

  If the received input level is lowered due to normal fading, the line is restored by restoring the fading condition. That is, when the reception input level rises and normal operation is performed, the line quality degradation information S2a and S2b are canceled, and when the reception input level rises beyond the first upper limit value, the transmission power control panel 25 sends a transmission output down signal. Is output as a transmission output level control signal S3. Then, when the reception input level becomes equal to or lower than the first upper limit value, the transmission output down signal stops, so that the operation returns to the steady operation without performing the transmission power control.

  Here, in consideration of equipment failure (including silent failure on the transmission side), the line quality degradation information S2a. S2b occurs. However, in the case of a device failure, the line quality deterioration information S2a and S2b continues because the device is not restored until the corresponding device is replaced or repaired. Therefore, when the line quality degradation information S2a and S2b continues for a certain period of time, a transmission output minimization control signal (hereinafter referred to as “equipment failure signal”) indicating a device failure is transmitted to the transceiver 10 as a transmission output level control signal S3. .

  Next, the operation of the transceiver 10 will be described. In the initial transmission output control operation, the transmission outputs of the transmission boards 11a and 11b are controlled based on the transmission output up signal and the transmission output down signal. Therefore, this transmission output control operation is continued until a device failure signal is detected.

  The operation after the device failure signal is detected will be described with reference to FIGS. When the control circuit 15 receives the transmission output level control signal S6 and detects a device failure signal (steps 101 and 102), the control circuit 15 transmits transmission switching signals S8a and S8b, turns off the mute circuit 12a, and turns off the mute circuit 12b. By switching on, switching to save the silent failure is performed (step 103). Conversely, the mute circuit 12a may be turned on and the mute circuit 12b may be turned off.

Subsequently, if the control circuit 15 continues to detect the device failure signal even after the fixed time τ ₁ elapses, the control circuit 15 transmits a transmission output minimizing signal that minimizes the transmission output of the transmission boards 11a and 11b to the transmission output control signal. Output as S7a and S7b (steps 104 to 106). This prevents interference. If the device failure signal is triggered by silent failure, the device failure signal is canceled after a certain period of time τ ₁ to restore the original transmission switching. It will return (steps 105 and 101).

After the transmission output minimization signal is output, the presence / absence of the device failure signal is checked every fixed time τ _{2, and when} there is no device failure signal, the normal transmission control operation is resumed (steps 107, 105, 101). At this time, instead of automatically recovering, the original transmission output control operation may be returned by an operation accompanying the replacement work of the maintenance worker.

  FIG. 4 is a block diagram illustrating a second example of a wireless communication system including the transmission power control apparatus of FIG. Hereinafter, a description will be given based on FIG. 2 and FIG. However, in FIG. 4, the same parts as those of FIG.

  In the transceiver 10 of FIG. 2, there are two duplexers 16a and 16b, the antenna 17b is shared, and the control circuit 15 outputs transmission mute signals S8a and S8b. On the other hand, in the transceiver 30 of FIG. 4, there is only one duplexer 36, the antenna 17b is dedicated for reception, the control circuit 35 outputs the transmission switching signal S9, and inputs the transmission switching signal S9. A switching circuit 37 for switching the connection is attached.

  In the transceiver 20 of FIG. 2, there are two duplexers 26a and 26b, and the antenna 27a is shared. On the other hand, in the transceiver 40 of FIG. 4, there is only one duplexer 46, the antenna 27a is dedicated for reception, and a switching circuit 47 is attached instead.

  The second example of FIG. 4 uses the transmission switching signal S9 instead of the transmission mute signals S8a and S8b as compared with the first example of FIG. 2, but either one of the output signals of the transmission boards 11a and 11b is used. It is the same in that it transmits from the antenna.

  Note that the transmission power control apparatus according to the present embodiment is not based on the reception-side device failure signal generation method at all, and is thus operable with many conventional device failure signal generation methods.

It is a block diagram which shows one Embodiment of the transmission power control apparatus which concerns on this invention. It is a block diagram which shows the 1st example of the radio | wireless communications system containing the transmission power control apparatus of FIG. 3 is a flowchart illustrating an example of the operation of the transmission power control apparatus in FIG. 1. It is a block diagram which shows the 2nd example of the radio | wireless communications system containing the transmission power control apparatus of FIG. It is a block diagram which shows 1st prior art. It is a block diagram which shows a 2nd prior art.

Explanation of symbols

10, 20, 30, 40 Transceiver 11a, 11b, 21a, 21b Transmitter panel 12a, 12b, 22a, 22b Mute circuit 13a, 13b, 23a, 23b Receiver panel 14, 37, 47 Switching circuit 15, 35 Control circuit (transmission) Power control device)
16a, 16b, 26a, 26b, 37, 47 Duplexer 24a, 24b BER detection circuit 25 Transmission power control panel 28 Branch circuit S1a, S1b Reception input level information S2a, S2b Line quality degradation information S3, S4a, S4b, S5a, S5b, S6 Transmission output level control signal (failure signal)
S7a, S7b Transmission output control signal (transmission output minimization signal)
S8a, S8b Transmission mute signal (transmission switching signal)
S9 Transmission switching signal

Claims (9)

A failure signal input means for inputting a failure signal related to the transmitter from a receiver facing a transmitter of a hot standby system having an active transmission unit and a standby transmission unit;
When the failure signal input means inputs the failure signal, a transmission switching signal output means for outputting a transmission switching signal for switching from the active transmission unit to the standby transmission unit;
Even if a fixed time has elapsed after the transmission switching signal is output by the transmission switching signal output means, the transmission output level of the standby transmission unit is minimized if the failure signal is input by the failure signal input means. A transmission output minimizing signal output means for outputting a transmission output minimizing signal,
A transmission power control apparatus comprising: The failure signal input means, the transmission switching signal output means and the transmission output minimization signal output means are provided in the transmitter,
The transmission power control apparatus according to claim 1. The transmitter is a first transceiver and the receiver is a second transceiver;
The transmission power control apparatus according to claim 1 or 2, characterized in that A first step of inputting a failure signal related to the transmitter from a receiver facing a hot standby transmitter having an active transmitter and a standby transmitter;
When this failure signal is input, a second step of outputting a transmission switching signal for switching from the active transmission unit to the standby transmission unit,
Third step of outputting a transmission output minimizing signal for minimizing the transmission output level of the standby transmission unit if the failure signal is input even if a certain time has elapsed after the transmission switching signal is output When,
Including a transmission power control method. The first step, the second step, and the third step are performed by the transmitter.
The transmission power control method according to claim 4. The transmitter is a first transceiver and the receiver is a second transceiver;
6. The transmission power control method according to claim 4 or 5, wherein: A failure signal input means for inputting a failure signal related to the transmitter from a receiver facing a hot standby type transmitter having an active transmission unit and a standby transmission unit;
When the failure signal input means inputs the failure signal, a transmission switching signal output means for outputting a transmission switching signal for switching from the active transmission unit to the standby transmission unit,
And if the failure signal is input by the failure signal input means even after a lapse of a certain time after the transmission switching signal is output by the transmission switching signal output means, the transmission output level of the standby transmission unit A transmission output minimizing signal output means for outputting a transmission output minimizing signal,
As a transmission power control program for causing a computer to function. The computer is provided in the transmitter;
The transmission power control program according to claim 7. The transmitter is a first transceiver and the receiver is a second transceiver;
The transmission power control program according to claim 7 or 8.

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