JPH0114741B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an element error measuring device that measures element errors representing the quality of a data line using a sine wave, which is advantageous in terms of bandwidth and simplicity. The present invention relates to an element error measuring device that can be varied.

A conventional element error measuring device of this type will be explained with reference to FIGS. 1 and 2 showing its configuration and time charts of each part. When the sine wave signal a output from the sine wave oscillator 2 passes through the communication line 1, which is the line to be measured, it is input to the waveform shaping circuit 3 after being subjected to amplitude and phase distortion. The waveform shaping circuit 3 generates a rectangular wave signal c that rises and falls from the distorted sine wave signal b at a predetermined rising side (+ side) slice level S ₊ and falling side (- side) slice level S _- . is generated and used as one input of the exclusive OR circuit 5. The rectangular wave signal c obtained at this time is
When the distorted sine wave signal b is waveform-shaped, the rising or falling side slice level S ₊
Or, if S _- is not reached, the previous state is maintained (Part A). On the other hand, the rectangular wave oscillator 4 has a reference waveform signal f, which is a rectangular wave having the same frequency as the sine wave oscillator 2, whose phase is controlled by using, for example, the rising edge of the rectangular wave c obtained by the waveform shaping circuit 3 as a synchronization detection point D. Then, a sampling signal g having twice the frequency of this reference waveform signal f is generated. Exclusive OR circuit 5
Then, the waveform-shaped signal c and the reference waveform signal f are subjected to an exclusive OR and compared, and a signal d indicating the result is input to the AND circuit 6. AND circuit 6
Then, the comparison result signal d based on the exclusive OR 5 and the sampling signal g are ANDed and compared, and the result of the comparison is output and detected as an element error e.

In the conventional element error measuring device as described above, the code transmission rate is fixed at twice the frequency of the sine wave signal (equal to the frequency of the sampled signal), so for example, if the frequency of the sine wave signal is 2000 Hz,
The code string repeats 1 and 0, and the code transmission rate is 4000.
Bits per second. Therefore, in order to increase the code transmission speed and improve the ability to detect element errors, it is necessary to increase the frequency of the sine wave signal each time.

Furthermore, since the sample signal that serves as a standard for element error detection is determined by the frequency of the sine wave signal, there is a possibility that error detection due to a momentary interruption of the communication line may become impossible. For example, in FIG. 2, even though the output B of the exclusive logic circuit 5 has detected a momentary interruption, it is not outputted as a signal of element error e because the timing does not match with the sampling signal g.

An object of the present invention is to provide element error measurement that eliminates the above-mentioned drawbacks, makes it possible to easily perform element error measurement for any code transmission rate, and that also sufficiently detects element errors caused by the effects of instantaneous interruptions, etc. The goal is to provide equipment.

In order to achieve the above object, the present invention is configured to make the sampling signal used for detecting element errors variable.

An embodiment of the present invention will be described below with reference to the drawings. FIG. 3 is a block diagram showing one embodiment of the present invention, in which the same reference numerals as in FIG. 1 indicate blocks and signals having the same functions. In this embodiment, a multiplier circuit 7 is provided between the rectangular wave oscillator 4 and the AND circuit 6 in order to make the period of the sampling signal g variable. Here, phase control in the square wave oscillator 4 is performed every cycle, and if there is no synchronization detection point, phase control is not performed, but the phase control is not limited to this and may be performed in any cycle. .

The sampling signal g synchronized with the reference waveform signal is converted by the multiplier circuit 7 into a sampling signal h having a frequency that is, for example, six times that of the sine wave signal a, in accordance with the code transmission rate. The exclusive OR circuit 5 compares the waveform shaped signal c with the reference signal, and the AND circuit 6 compares the comparison result signal d with the sampling signal h obtained by multiplying the sampling signal g. Detect error e. At this time, since the period of the sampling signal h is arbitrarily variable, an error B due to momentary interruption
can also be detected sufficiently.

According to the embodiment described above, the frequency of the sinusoidal signal is 6
1, 1, 1, as a code string at twice the code transmission speed
Element errors of repeating 0, 0, 0 can be measured. This code transmission rate is determined by the frequency of the sampling signal, and if this frequency is n times the frequency of the sine wave signal, it is possible to measure element errors for a code transmission rate that is n times higher. For example, if the sine wave signal is 2100Hz and the sampling frequency is 20 times that of the sine wave signal, the code string will be 1, 1, 1, 1, 1, 1, 1, 1, 1,
By repeating 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, the code transmission rate can be increased to 42K bits/second.

Furthermore, according to the present invention, when the output of the communication line is waveform-shaped and does not reach the slice level on the rising side (+ side) or the falling side (- side), the waveform-shaped output maintains the previous state. However, since element errors corresponding to the code transmission rate are detected, it is also possible to measure the instantaneous interruption time of the communication line.

As explained above, the present invention sets the sampling frequency to the frequency corresponding to the desired code transmission rate without changing the frequency of the sine wave signal, so element errors for arbitrary code transmission rates can be extremely easily prevented. It has the remarkable effect of being able to measure element errors caused by instantaneous interruptions in communication lines, etc.

[Brief explanation of drawings]

1 and 2 are block diagrams of a conventional element error measuring device and time charts of signals of various parts in FIG. 1, and FIG. 3 and 4 are block diagrams of an element error measuring device according to an embodiment of the present invention. 4 is a time chart of signals of various parts in the figure and FIG. 3. 1...Communication line, 2...Sine wave oscillator, 3...
Waveform shaping circuit, 4... Rectangular wave oscillator, 5... Exclusive OR circuit, 6... AND circuit, 7... Multiplier circuit.

Claims (1)

[Claims] 1 means for sending a sine wave signal to a communication line; means for generating a shaped signal by slicing and shaping the sine wave signal distorted by the communication line at a predetermined level; and means for generating a shaped signal in synchronization with the shaped signal. means for generating a reference signal having the same frequency as , means for comparing the reference signal and the shaped signal and extracting signal components that do not match, and generating a sampling signal having a desired frequency in a frequency variable manner. means and
An element error measuring device comprising: an AND circuit that detects an element error for each sampled signal by performing a logical product of the sampled signal and the signal component.