JPH0773244B2 - Diversity reception system - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a diversity receiving system having a plurality of receiving systems, and in particular, a working receiver (hereinafter, simply working machine) and a spare receiver (hereinafter, simply spare machine). ) Is related to the switch.

(Prior Art) Usually, in order to determine the failure of the receiver, the intermediate frequency (I
F) The output level or the limiter current value is monitored, and a method that determines that it has dropped below the preset reference value is determined to be a failure. A similar method is used for receiver switching in the diversity method. It had been. However, in the case of the receiver using the diversity method adopting these methods, it is difficult to determine whether it is due to a drop in the received electric field or due to a failure of the receiver itself. It had the following system configuration.

In FIG. 2, reference numeral 1 denotes a first reception system, an antenna 2 for receiving a transmission wave, a demultiplexer 3 for demultiplexing the reception wave from the antenna 2 into an active machine 4 and a standby machine 5, and an active machine. 4 and the standby unit 5, and comprises a comparator 6 for monitoring and comparing the outputs, and a switching unit 7 for selecting and outputting one of the outputs of the active unit 4 and the standby unit 5 according to an instruction from the comparator 6. There is.
1a is a second receiving system, which has the same configuration as the first receiving system 1 and is composed of an antenna 2a, a duplexer 3a, a working device 4a, a standby device 5a, a comparator 6a and a switching device 7a. There is. 8 is a comparator,
The outputs from the first receiving system 1 and the second receiving system 1a are monitored and compared. Reference numeral 9 is a switching device, and the first device is operated by the instruction of the comparator 8.
One of the receiving system 1 and the second receiving system 1a is selected and output.

In the configuration as described above, first, each reception system 1 and
In 1a, the electric field strength was determined, and then the receiving system showing the output showing the optimum electric field strength was selected and output as the receiving output.

(Problems to be Solved by the Invention) However, according to the above method, one working machine 4, 4a and one standby machine 5, 5a must be provided for each of the two receiving systems 1, 1a. However, there is a problem that the cost of the system is increased, the packaging density is high, and the circuit configuration is complicated.

In view of the above problems, it is an object of the present invention to provide a diversity reception system that does not require a standby device for each reception system and can realize system cost reduction and simplification of the configuration.

(Means for Solving the Problems) In order to achieve the above object, the present invention receives a transmission wave by a plurality of working receivers, selects one output from the outputs of each working receiver, and receives the output. If a failure occurs in the working receiver, in the diversity reception system that switches from the failed working receiver to the standby receiver to receive, the operating rate or the number of times of operation of multiple working receivers within a preset time The failure working receiver is discriminated based on the deviation of the operating rate or the operating frequency from a preset reference value.

(Operation) According to the present invention, the transmitted wave is received by a plurality of working receivers,
By selecting one of the outputs of these working receivers as a reception output and monitoring the working ratio or the number of working times of each working receiver within a predetermined time,
A defective working receiver can be discriminated by the deviation of the operating rate or the number of times of operation from the reference value, and a spare receiver can be assigned to the defective working receiver in accordance with this discrimination.

(Embodiment) FIG. 1 is a block diagram showing an embodiment of the present invention.
In the figure, 10 and 10a are antennas, 11 and 11a and 12 are switching devices, and 13 and 13a
Is a working machine, 14 is a standby machine, 15 is a 3-input selector, 16 is a comparison controller, and 17 is a watchdog timer.

The switching device 11 switches the connection based on an instruction from the comparison controller 16 in order to input the received wave from the antenna 10 to either one of the working device 13 and the standby device 14, and normally receives it to the working device 13. It is designed to output waves.

The switching device 11a performs connection switching based on an instruction from the comparison controller 16 in order to input the received wave from the antenna 10a to either one of the active device 13a and the standby device 14, and normally receives it to the active device 13a. It is designed to output waves.

When a failure occurs in either the active machine 13 or the active machine 13a, the switcher 12 sends the received wave from the switcher 11 or the switch 11a based on the instruction from the comparison controller 16 to the standby machine 1
Switch the connection for input to 4.

The 3-input switch 15 inputs the output A of the active machine 13, the output B of the active machine 13a, or the output C of the standby machine 14, and outputs these outputs A and B.
Alternatively, in order to output one of the outputs of C as a reception output, connection switching is performed based on an instruction from the comparison controller 16.

The comparison controller 16 inputs the output A of the active machine 13, the output B of the active machine 13a, or the output C of the standby machine 14, selects a signal showing the optimum received electric field strength from these inputs, and selects the result. The control signal CTL1 based on it is output to the 3-input switch 15 to instruct the connection switching so as to obtain the optimum reception output, and the watchdog timer 17 is supplied with the operation signal AS indicating the operating status of the active machines 13, 13a. Output. Further, based on the discrimination signal DS from the watchdog timer 17 described later, the active machine
When it is determined that one of the 13 or the active machine 13a has failed, the control signal CTL2 is output to the switch 11 or the control signal CTL3 is output to the switch 11a, and the control signal CTL is output.
4 is output to the switching unit 12 to instruct connection switching, and the standby unit 14 is assigned to the working unit 13 or the working unit 13a which is determined to be in failure.

The watchdog timer 17 receives an operation signal from the comparison controller 16.
By inputting the AS, the operating rate of the active machine 13 and the active machine 13a within a preset predetermined time is monitored, and the faulty active machine is discriminated by the deviation of the operating rate, and the discrimination signal
The DS is output to the comparison controller 16.

FIG. 3 is a block diagram showing the configuration of the watchdog timer 17. In FIG. 3, 17a is a clock generator that generates and outputs a clock CLK at a predetermined cycle, and 17b is a clock.
A counter for counting CLK, 17c is an AND circuit, which performs a logical product of the operation signal AS1 output from the comparison controller 16 and indicating the operating status of the active machine 13 and the clock CLK, and outputs the output signal CLK1.
Is output. 17d is an AND circuit, which is an operation signal AS2 output from the comparison controller 16 and indicating the operating status of the active machine 13a and a clock.
Performs a logical product with CLK and outputs the output signal CLK2. 17e
Is an up-down counter that counts up when the output signal CLK1 of the AND circuit 17c is input to the input UP and AND is input to the input DN.
When the output signal CLK2 of the circuit 17d is input, it counts down. Reference numeral 17f denotes a discrimination circuit, which recognizes a preset predetermined time from the count value of the counter 17b, and if the count value of the up / down counter 17e at the time when the predetermined time has elapsed is larger than the preset first reference value RF1, It is determined that a failure has occurred in the active machine 13a, and the determination signal DS2 is output to the comparison controller 16
Output to. On the other hand, the count value of the up / down counter 17e is the second preset reference value RF2 (where RF1> RF
If it is smaller than 2), it is determined that a failure has occurred in the active machine 13, and a discrimination signal DS1 is output to the comparison controller 16.

FIG. 4 is a waveform diagram showing an operation example of FIG. According to FIG. 4, the working machines 13 and 13a operate in a normal state with a probability of about 1/2, and the comparison controller 16 sends the operation signals AS1 and AS2 to the watchdog timer 17 alternately at a high level "1". What had been input, but because some failure occurred in the active machine 13, at the point a in the figure, only the operation signal AS2 was input at the high level "1", which caused the up-down counter 17e to perform only the down-count operation. , The count value of the up / down counter 17e becomes the second value within a predetermined time from point a to point b in the figure.
It becomes smaller than the reference value RF2 of the above, and at the point b, the discrimination circuit 17f outputs the discrimination signal DS1 indicating that a failure has occurred in the working machine 13 to the high level "1" and outputted.

Next, the operation of the above configuration will be described.

First, in a normal state, the received wave via the antenna 10 is input to the active machine 13 via the switch 11, and the active machine 13 outputs the output A to the 3-input switch 15 and the comparison controller 16. On the other hand, the received wave via the antenna 10a is transmitted via the switch 11a to the active machine 13
Inputted to a, the active machine 13a outputs the output B to the 3-input switch 15 and the comparison controller 16. The comparison controller 16 compares the input outputs A and B and selects a signal indicating the optimum received electric field strength. For example, if it is determined that the output A from the active machine 13 is better, the control signal CTL1 is set to 3 The output signal is output to the input switcher 15 to instruct to output the output A of the active machine 13 as a reception output, and the operation signal AS1 indicating the operating status of the active machine 13 is set to a high level "1" and output.

Here, for example, when some failure occurs in the active machine 13 and the operating rate of the active machine 13 is significantly reduced, the operation signal AS1 from the comparison controller 16 becomes a low level “0”. As a result, the watchdog timer 17 recognizes that the count value of the up / down counter 17e has become smaller than the reference value RF2 at the time when a predetermined time has elapsed, and the determination circuit 17f recognizes that a failure has occurred in the active machine 13. Then, the discrimination signal DS1 is set to the high level "1" and output to the comparison controller 16. Comparison controller 16 is a discrimination signal
When DS1 is input at high level "1", the control signal CTL2 is switched 1
In addition to outputting to 1, the control signal CTL4 is output to the switch 12, so as to switch the connection for inputting the received wave received by the antenna 10 to the standby unit 14, that is, the standby unit 14 to the active unit 13. Instruct to allocate.

With this switching operation, the received wave via the switches 11 and 12 is input to the standby unit 14, and the standby unit 14 outputs the output C to the 3-input switching unit 15.
And output to the comparison controller 16. The comparison controller 16 is a standby unit 14
If the output C of the spare device 14 is determined to be better, the control signal CTL1 is set to the control signal CTL1. The output is output to the 3-input switch 15, and the output C of the standby unit 14 is instructed to be output as the reception output.

FIG. 5 is a diagram showing an example of a counter configuration when the determination is made based on the number of times the receiver has been operated, without using the watchdog timer 17. According to FIG. 5, the operation number counter is composed of, for example, a 4-bit up / down counter 17g, and the operation signal MS1 indicating the operation state of the working machine 13 is input to the input UP.
Is input, and the operation signal MS2 indicating the operating state of the active machine 13a is input to the input DN. This up-down counter 17g
Counts up when the operation signal MS1 is input, continuously counts the operation signal MS1 by, for example, 16 and outputs a carry signal CRY indicating a failure of the active machine 13a to the comparison controller 16 when in the carry state. On the other hand, when the operation signal MS2 is input and the countdown occurs and the borrow state is reached, the borrow signal BRW indicating the failure of the active machine 13 is output to the comparison controller 16, and the other component operation in FIG. It is the same as the above case. FIG. 6 shows an operation example of FIG. 5 when the active machine 13a fails.

According to the present embodiment, the operating states of the active machine 13 and the active machine 13a are monitored by the watchdog timer circuit 17 or the operation counter 17g, and the active machine that has failed due to the deviation of the operating rate or the operational frequency of the active machine is determined. Then, in accordance with this determination, the comparison controller 16 uses the control signals CTL2 to CTL4 to switch the switches 11, 11a, 12
Since the spare machine 14 is assigned to the working machine that has failed by performing the switching control of the above, it is only necessary to provide one spare machine, which leads to cost reduction.
It is possible to simplify the configuration.

(Effects of the Invention) As described above, according to the present invention, a transmitted wave is received by a plurality of working receivers, and one of the outputs of each working receiver is selected as a reception output. In the diversity reception method, in which if a receiver fails, the failed active receiver is switched to the standby receiver for reception, and the operating rate or number of operations of multiple active receivers within a preset time is monitored. Since the failure working receiver is discriminated based on the deviation of the operating rate or the number of times of operation from the preset reference value, only one standby machine needs to be installed regardless of the number of working machines. Therefore, there is an advantage that the cost of the entire receiving system can be reduced, the volume ratio can be reduced in terms of mounting, and the configuration can be simplified.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a system configuration diagram of a conventional example, FIG. 3 is a circuit diagram of a watch dog timer according to the present invention, and FIG. 4 is a diagram of FIG. FIG. 5 is a waveform diagram showing an operation example, FIG. 5 is a circuit diagram showing a configuration example of an operation number counter according to the present invention, and FIG. 6 is a waveform diagram showing an operation example of FIG. In the figure, 10,10a ... antenna, 11,11a, 12 ... switch, 13,
13a …… Current receiver, 14 …… Spare receiver, 15 …… 3 input selector, 16 …… Comparison controller, 17 …… Watchdog timer.

Claims (1)

[Claims] 1. A plurality of active receivers for receiving a carrier wave, a determining means for determining an electric field strength at an output of the active receiver, and a plurality of active receivers based on selection information output from the determining means. In the diversity reception system, which comprises a selecting means for selecting an optimum one output from among the outputs of the receivers as a reception output, and a standby receiver and the selection information output from the judging means, Monitoring which output of the current receiver is selected within a predetermined time, and monitoring that determines the current receiver whose operating rate or number of times each of the current receivers does not reach a predetermined reference value as a failure. Means and switching means for switching from the working receiver, which does not reach the reference value, to the backup receiver based on the determination result of the monitoring means. Diversity reception method.