| 摘要 |
PURPOSE:To generates an error very at random even in an area where an error rate is low by correlating an input digital signal with a PN pattern, and inserting the error the input digital signal according to the correlation output. CONSTITUTION:A generators 24 for a PN pattern of (n)th degree generates (n) phases of PN patterns having a period 2<n>-1 period with an input clock and supplies them to a correlation detector 25. The detector 25 detects mutual correlations between the (n) phases of PN patterns and an input signal and sends a correlation output to an error inserting circuit 26. The circuit 26 inverts the polarity of the input signal and outputs it to insert an error only when the correlation output from the detector 15 exists, and passes the input signal as it is when not. The input signal is generally irrelevant to the PN patterns, so the detector detects the correlation between the both to obtain random patterns, generating random errors. |
