JPS6243622B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a receiver equipped with self-diagnosis means used in a communication system in which a reception waiting state exists.

In a communication system in which multiple reception channels are assigned, multiple reception channels are not selected at the same time, and when one of the multiple reception channels is selected, other reception channels are in a reception waiting state. shall be. In such a communication system, the receiver is not always used for communication, but can be kept in a standby state.
Conventionally, self-diagnosis of a receiver placed in a reception standby state has been performed in the following manner. That is, oscillators for generating pseudo input signals having a frequency equal to the reception frequency are provided in a number equal to the number of reception channels, and the number of oscillators is set according to the reception channels assigned to the receiver to be diagnosed. Only the oscillator for generating a pseudo input signal with a frequency equal to the frequency of is controlled and operated.

The output of this oscillator is applied to the input coupling part of the main body high frequency amplification system of the receiver to be diagnosed, and the signal obtained from the output terminal of this main body high frequency amplification system is compared with the output signal of the oscillator. If the two signals match, the receiver is operating satisfactorily; if the two signals differ, the receiver is determined to be malfunctioning. This method not only requires the oscillator to have high frequency stability, but also requires a number of oscillators equal to the number of reception channels, which has the drawback of making the receiver very expensive.

It is an object of the present invention to overcome the above-mentioned drawbacks by employing one supervisory noise generator, which has a spectral distribution in a band that includes all of the plurality of receiving channels, instead of the plurality of oscillators. Another object of the present invention is to provide a receiver equipped with a self-diagnosis means that has a simplified configuration and a compact structure.

According to the present invention, the self-diagnosis means in a receiver equipped with self-diagnosis means is constructed using a monitoring noise generator and a comparator. The monitoring noise generator is for generating a diagnostic signal having a spectral distribution including all reception channels, and is composed of a random pulse generator, a carrier generator, and a modulator. The random pulse generator generates a random pulse signal having a random pulse width and a random pulse period. The carrier generator generates a carrier signal, and the frequency of this carrier exists at one point within a band that includes all reception channels. The modulator modulates the carrier signal with a random pulse signal, and a diagnostic signal is obtained from the output terminal of the modulator. The diagnostic signal has a spectral distribution that includes all of the receiving channels. The diagnostic signal is divided into two systems, one being directly applied to the first input terminal of the comparator, and the other being applied to the input coupling section of the high frequency amplification system of the receiver main body. The signal obtained from the output terminal of the high frequency amplification system is applied to the second input terminal of the comparator. The comparator compares both signals, and when a matching output is obtained at the output terminal, it is determined that the receiver is operating satisfactorily. If the two do not match, it is determined that the receiver is malfunctioning.

A receiver according to the present invention will be explained in detail below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a receiver equipped with self-diagnosis means. In Fig. 1, the radio waves arriving at the receiving antenna 1 are transmitted to the coupler 2.
The signal is applied to the high frequency amplifier 3 through. The output of the high frequency amplifier 3 is applied to a mixer 4 where it is mixed with the signal from the local oscillator 9. The output of the mixer 4 is applied to a demodulator 6 via an intermediate frequency amplifier 5. A high frequency amplification system 30 is formed from the coupler 2 to the intermediate frequency amplifier 5.

The output of the demodulator 6 is amplified by a low frequency amplifier 7 and appears at a low frequency output terminal 8. Meanwhile, another output from the intermediate frequency amplifier 5 is applied to an electric field detector 10 having a squelch function, where an output is obtained only when the input electric field is above a preset value. A control signal indicating that the receiver is in a reception waiting state is applied to the control terminal 14, and when this reception waiting state signal is applied, the monitoring noise generator 13 operates, and the diagnostic signal generates monitoring noise. output from the device 13. The diagnostic signal is applied to the combiner 2 and to the first input terminal 41 of the comparator 11. The output signal of the electric field detector 10 is applied to a second input terminal 42 of the comparator 11.
Both signals are compared in a comparator 11 and an output representing a match or a mismatch is obtained from the output terminal 12 of the comparator. When the signals at output terminals 12 indicate a match, the receiver is operating satisfactorily; when it indicates a mismatch, the receiver is at fault.

FIG. 2 is a block diagram showing a first embodiment of the monitoring noise generator 13. The terminal 19 is a terminal for inputting a control signal for controlling the carrier generating section 15 and the random pulse generating section 17, and is connected to the control terminal 14. Carrier generating section 15
The carrier signal generated is applied to the modulator 16, and the modulator 16 balance-modulates the carrier signal with the random pulse signal from the random pulse generator 17. The spectrum distribution of the modulated signal appearing at the output terminal 18 is such that the spectrum of the random pulse generating section 17 is centered around the frequency of the carrier signal from the carrier generating section 15 and expands into the upper and lower frequency ranges.

FIG. 3 is a block diagram showing a second embodiment of the monitoring noise generator 13. In FIG. 3, the output of the modulator 16 is multiplied by N in the multiplier 20 and sent to the output terminal 18. Since the carrier generator 15 and the random pulse generator 17 operate within a frequency band that is 1/N of the reception band, it is easy to widen the band by N multiplication.

According to the present invention, a wideband diagnostic signal is obtained by a monitoring noise generator having wideband characteristics.
If the spectral distribution of the diagnostic signal sufficiently covers the entire reception channel, self-diagnosis can be performed without the need for multiple oscillators with high stability as in conventional systems, simplifying the configuration of the receiver. In addition to being smaller and lighter, the receiver can be constructed economically.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of a receiver equipped with self-diagnosis means according to the present invention, and FIGS. 2 and 3 are configurations of a monitoring noise generator used in the receiver of FIG. FIG. 2 is a block diagram showing an embodiment of the invention. DESCRIPTION OF SYMBOLS 1... Antenna, 2... Coupling unit, 3... High frequency amplifier, 4... Mixer, 5... Intermediate frequency amplifier, 6... Demodulator, 7... Low frequency amplifier, 9... Local oscillator, 10...
Electric field detector, 11... Comparator, 13... Monitoring noise generator, 30... High frequency amplification system, 15... Carrier generation section, 16... Modulation section, 17... Random pulse generation section, 20... Multiplier section, 8, 12, 14, 18, 19
...Terminal.

Claims (1)

[Claims] 1 Self-diagnosis used by a communication system that has a plurality of reception channels that are not selected simultaneously and in which other reception channels are in a waiting state when one of the reception channels is selected. a monitoring noise generator for generating a diagnostic signal having a spectral distribution including all of the receiving channels; and a first noise generator for directly inputting the diagnostic signal. a comparator having an input terminal and a second input terminal for inputting the diagnostic signal via the main body high frequency amplification system of the receiver, the monitoring noise generator is inside the receiver; a random pulse generator for generating a random pulse signal driven by the generated control signal and having a random pulse width and pulse period; and a random pulse generator for generating a random pulse signal having a random pulse width and pulse period; and a modulation unit for modulating the carrier signal from the carrier generation unit with a random pulse signal from the random pulse generator to obtain a diagnostic signal, The present invention is characterized in that by applying the diagnostic signal to the comparator using the method during the time in the reception waiting state, a match output or a mismatch output is obtained from the comparator to perform self-diagnosis. A receiver equipped with self-diagnosis means.