Patent ID: 6928171

Claim:
A circuit for the calculation of two de-correlated digital output signals (s 1 , s 2 ) from two correlated digital input signals (y 1 , y 2 ), said circuit comprising two filters arranged symmetrically crosswise in a forward direction ( 17 , 18 ) with adaptive filter coefficients (w 1 , w 2 ), two retarding elements ( 7 , 8 ) and two subtractors ( 9 , 10 ) for calculation of the output signals (s 1 , s 2 ) within a time range from the input signals (y 1 , y 2 ), while minimizing a quadratic cost function consisting of cross-correlation terms, wherein the circuit includes four cross-over element filters ( 19 - 22 ) for transformation of the input and output signals (y 1 , y 2 ; s 1 , s 2 ) in dependence of the signal and wherein all calculation units for updating of the filter coefficients (w 1 , w 2 ) are in the circuit following the cross-over element filters ( 19 - 22 ).