Decision feedback equalizer with adaptive filter array operating as feedforward filter of the equalizer

A decision feedback equalizer for an array of antennas receiving a modulated carrier with a plurality of receiver means connected respectively to the antennas for recovering a plurality of symbol sequences from the carrier, said antennas being spaced at intervals equal to one-half of the wavelength of said carrier, the decision feedback equalizer comprising:

• first filter means connected to the receiver means and respectively multiplying said symbol sequences with first weight coefficients;
• combiner means combining the multiplied symbol sequences from said first filter means with second symbols applied thereto and producing therefrom a combined symbol sequence;
• decision means making a decision on the combined symbol sequence and producing therefrom a decision symbol sequence;
• second filter means multiplying decision symbols successively supplied from said decision means respectively with second weight coefficients and applying the multiplied decision symbols as said second symbols to said combiner means;
• error detector means detecting a difference between said decision symbol sequence and said combined symbol sequence and deriving therefrom a decision error;
• first update means updating said first weight coefficients with correlations between said decision error and the symbol sequences from said receiver means so that a mean square of said decision error is reduced to a minimum value;
• and
• second update means updating said second weight coefficients with correlations between said decision error and decision symbols successively supplied from the decision means so that the mean square of said decision error is reduced to the minimum value.