SYSTEM FOR DETECTING DETERIORATION OF SIGNAL

摘要

PURPOSE:To attain simple automatic equalizing system with high accuracy by detecting the deterioration of an amplitude characteristic of a recording and reproducing system form a level difference between a peak level of an envelope of a frequency in a signal reproduced from a burst signal and a level at a DC period. CONSTITUTION:Circuits comprising an integrator 3 - an AD converter 7 process a signal and display the deterioration of the frequency characteristic of the recording and reproducing system in a binary number. A data processing section 8 generates a control signal required to control a frequency characteristic compensating device 2 based on the binary data. The basic operation of the data processing section 8 is as follows: A false sample value is eliminated and the mean value of samples of frequency corresponding to the same frequency of a multi-burst signal is obtained. Then each frequency ratio of the ideal characteristic satisfying the Nyquist condition is obtained in advance and incorporated in the memory. The ratio of each frequency is obtained by using a data obtained from the recording and reproducing system and subject to the said processing. The error (square mean error) between the ratio and the said ideal value is obtained and the frequency characteristic compensating circuit 2 is set so as to minimize the mean square error E.