Waveshaping circuit for shaping an analog waveform having unequal

Abstract

An analog waveshaping circuit is capable of performing waveshaping of an AC analog signal in which the positive and negative peak levels with respect to a reference level are not the same, while considering a DC offset component of the reference level of the analog waveform, so that the positive and negative levels with respect to the reference level are made equal. The analog signal waveshaping circuit to do this is formed by a (1+D) equalizing circuit, an interference detecting circuit which, if the input and output signals of the means for equalizing being X(n) and Y(n), respectively and the interference state from signal X(n) to signal Y(n) is S(n) at the time n, uses a signal X(n) 3-value comparator circuit, a signal Y(n) 3-value comparator circuit, and a state processing circuit to calculate what interference condition occurred of the 7 possible types which are possible from the three values that the signal X(n) can take to the three values that the signal Y(n) can take, this being output by the interference detecting circuit as the interference state S(n), a compensation constant generating circuit which classifies the interference state S(n) into three classes and stores these, and which performs further processing to detect a compensation constant and the DC offset contained in the signal Y(n), an amplitude compensating circuit which compensates the amplitude of the signal Y(n) in accordance with the compensation constant from the compensation constant generating circuit, and a data detecting circuit.