JP2616508B2 - Monitoring signal detection method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to monitoring signal detection for optical repeaters.
Outgoing system.

[0002]

2. Description of the Related Art In a conventional monitoring signal detection system of this kind,
As a superimposition method of a supervisory signal, a mark rate modulation scheme that modulates a mark rate of binary data with a supervisory signal during non-service, or a parity violation scheme that causes a parity violation in communication data with a supervisory signal at the time of service is provided. is there.

[0003]

SUMMARY OF THE INVENTION Such conventional monitoring
In the superimposition method of the monitoring signal in the signal detection method , the mark rate modulation method has a drawback that it cannot be applied in the service state, and the parity violation method has a low code error.

[0004]

According to the present invention, there is provided a monitoring signal detecting method according to the present invention.
The output method is based on the basic cycle of the first binary electric signal which is the main signal.
Response to the presence of the first monitoring signal that changes in a cycle longer than the
Amplitude-modulating the first binary electric signal and generating an optical signal
Receives the binary optical signal transmitted by converting to
Convert to an electrical signal and output as a second binary electrical signal
Light receiving means, and the second binary from the light receiving means
Of the first binary electric signal based on the electric signal
Generates a timing to reproduce a clock signal with the same cycle as the cycle
Generating means, and the second binary electricity from the light receiving means.
A clock signal from the timing generating means;
The first binary before being amplitude modulated, identified by
As a third binary electric signal corresponding to the electric signal
Identification reproducing means for outputting, and the
2 to detect the average voltage of the binary electric signal,
First average voltage detecting means for outputting as a pressure signal;
Average electric power of the third binary electric signal output from the identification reproducing means.
A second average voltage signal detected and output as a second average voltage signal.
Average voltage detection means, and the first average voltage detection means
The first average voltage signal and the second average voltage detection means
Comparing the second average voltage signal from the first stage to the first
Signal ratio for detecting a second monitor signal corresponding to the monitor signal of
Comparing means.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of one embodiment of the present invention, and FIG. 2 is a signal waveform diagram illustrating the operation of the present embodiment. Referring to FIG. 1, a monitoring signal detection method according to the present invention
Is greater than the fundamental period of the first binary electrical signal which is the main signal.
Is the first 2 depending on the presence or absence of a monitoring signal that changes in a long cycle.
Value electrical signal is amplitude modulated and converted to an optical signal for transmission.
Receiving the binary optical signal and converting the optical signal to an electrical signal.
Receiving a signal a as a second binary electrical signal
Circuit 1 and the second binary electric signal from the optical receiving circuit 1
Basic period of a first binary electric signal based on a certain signal a
Circuit 2 that reproduces a clock signal having the same cycle as
And a signal which is a second binary electric signal from the optical receiving circuit 1.
Signal a is identified by the clock signal from the timing circuit 2.
Corresponding to the first binary electric signal before being amplitude-modulated
For reproducing and outputting the signal b which is the third binary electric signal.
Another circuit 3 and a second binary electric signal output from the optical receiving circuit 1
To detect a first average voltage signal
An average voltage detection circuit 4 that outputs a signal c
Average of signal b, which is the third binary electrical signal output from circuit 3
Detecting a voltage and outputting a signal d as a second average voltage signal
From the average voltage detection circuit 5 and the average voltage detection circuit 4
Signal c as a first average voltage signal and average voltage detection circuit 5
From the second average voltage signal d.
Monitor signal e on the transmission side obtained by amplitude-modulating the binary electric signal of 1
Circuit 6 for detecting and outputting
And a monitoring circuit 7 operated by the visual signal e.
Next, the operation will be described with reference to FIG.
You. In this embodiment, the target for receiving and detecting the monitoring signal is
Signal, when superimposing the supervisory signal on the binary optical signal at the transmission side, Mitsunobu which increases the amplitude of the optical pulse signal is sent Den
No. that is intended for. On the receiving side, the optical signal on which the amplitude is superimposed is converted into an electric signal by the optical receiving circuit 1 and then discriminated and reproduced by the discriminating circuit 3 using the clock reproduced by the timing circuit 2. As shown in FIG. 2, the signal a output from the optical receiving circuit 1 has different pulse amplitudes P1 and P2 between when the monitoring signal is not transmitted before time A and when the monitoring signal is transmitted after time A. On the other hand, the signal b output from the identification circuit 3 has a pulse amplitude
Is constant. Therefore, the level of the signal C output from the average voltage detection circuit 4 varies depending on the presence or absence of the monitoring signal.
The level of the signal d output from the average voltage detection circuit 5 is constant. By comparing both levels of the signals c and d by the comparison circuit 6, the signal e can be obtained and the monitoring signal can be demodulated, and the monitoring circuit is operated.

[0007]

As described above, according to the present invention, an optical signal transmitted by changing an optical signal amplitude by a monitoring signal is transmitted.
By detecting the average amplitude on the receiving side and reproducing the monitor signal, the monitor signal can be transmitted even in the service state, and the code error tolerance does not deteriorate.

[Brief description of the drawings]

FIG. 1 is a block diagram of an embodiment of the present invention.

FIG. 2 is a signal waveform diagram according to the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Optical receiving circuit 2 Timing circuit 3 Identification circuit 4, 5 Average voltage detection circuit 6 Comparison circuit 7 Monitoring circuit

Claims (1)

(57) [Claims] (1)Base of the first binary electric signal which is the main signal
Presence / absence of the first monitoring signal that changes in a cycle longer than this cycle
Amplitude modulates the first binary electric signal according to
Receives a binary optical signal that has been converted to a signal and transmitted
To an electrical signal and output as a second binary electrical signal.
Light receiving means for powering; Based on the second binary electric signal from the optical receiving means
Of the same period as the basic period of the first binary electric signal.
Timing generating means for reproducing a clock signal; The second binary electric signal from the optical receiving means
Identification by the clock signal from the timing generation means
The first binary electric signal before being subjected to the amplitude modulation
For reproducing and outputting as a third binary electric signal corresponding to
Another reproduction means, Average of the second binary electric signal output from the light receiving means
A first detecting means for detecting a voltage and outputting it as a first average voltage signal;
Average voltage detecting means, The average of the third binary electric signal output from the discrimination / reproduction means.
Detecting the average voltage and outputting it as a second average voltage signal.
2 mean voltage detecting means; The first average voltage from the first average voltage detection means
Signal and the second average signal from the second average voltage detecting means.
Comparing with the equalized voltage signal and corresponding to the first monitoring signal.
Signal comparing means for detecting a second monitoring signal; Having
A monitoring signal detection method characterized by the following.