| 摘要 |
PURPOSE:To obtain resistance to a noise by deciding the convergence of an equalizer by ANDing the repetitive frequency of a tap coefficient with a pattern detection signal. CONSTITUTION:A signal (e.g. AMI code sequence) applied to an input terminal 2-1 is led to an output terminal 2-2 through a correcting signal adding circuit 2-9 and an identifying circuit 2-3, and part of this signal is applied to a pattern detecting circuit 2-5. This pattern detecting circuit 2-5 when detecting specific patterns of 0, + or -1, 0, and 0 sends the pattern detection signal to one input terminal of an AND circuit. The signal from an error polarity detector 2-4, on the other hand, is applied to the other terminal of said AND circuit and ANDed with said pattern detection signal. Consequently, a tap coefficient counter 2-6 counts up or down according to the value of the AND between the error polarity signal (repetitive frequency of tap coefficient) and pattern detection signal to reach convergence. |
