| 摘要 |
PURPOSE:To make it possible to measure the quality of the degradation of non-stationary short time fluctuation such as impulse noise, or instantaneous cutoff of signal that is received in a data transfer line by comparing an error signal with a threshold value that is a predetermined multiple of average error signal. CONSTITUTION:A receiving demodulating signal 1 is equalized for distortion by an automatic equalizer 3, and a result is output as an equalizer output 2 to a discriminating circuit 5. Next, a signal point is discriminated by the discriminating circuit 5, and the difference between the discriminated signal point and a theoretical inversion signal point is fed back as an error signal output 4 to an automatic equalizer 3, and further is input to a comparator 9. Furthermore, an average error signal 6 is input in the comparator 9 to set a predetermined multiple of the average error signal for a threshold value, and when the error signal exceeds the threshold value continuously a predetermined number of times, a pulse is output, the priority of outputting pulses for white noise distribution becomes very small, when an error signal increases for a short period of time due to impulse noise, a pulse is output. |
