Equalization apparatus with effective coefficient updating operation

An equalization apparatus for use in a television signal receiving system, which includes an equalizing filter having a set of equalizer coefficients for equalizing an input television signal distorted from an original signal to produce a filtered output signal, wherein the input television signal includes a plurality of data samples and the filtered output signal has a corresponding plurality of filtered output data samples;

• and an updating circuit for generating, in response to a data sample and a filtered output data sample corresponding thereto, a set of updated equalizer coefficients as the set of equalizer coefficients for the equalizer filter, characterized in that said updating circuit comprises:
• error generating means, in response to the filtered output data sample, for generating an error value denoting the difference between the filtered output data sample and a predetermined expected value and for generating a mean square error value of the error value;
• weight factor generation means for generating a first weight factor and a second weight factor based on the mean square value, wherein the second weight factor is determined as (1-the first weight factor);
• memory means for storing the set of updated equalizer coefficients as a set of previous equalizer coefficients;
• first calculation means for multiplying the data sample, the filtered output date sample, a predetermined step size, the first weight factor and the error value to generate a first calculation value;
• second calculation means for multiplying the second weight factor, the error value and a random value arbitrarily selected from a Cauchy distribution function to provide a second calculation value;
• and
• means for adding the first and the second calculation values to the set of previous equalizer coefficients to produce a set of updated equalizer coefficients as the set of equalizer coefficients for the equalizer filter.