An Application of the Cooley-Tukey Algorithm to Equalization

A new method is proposed to determine the tap settings of a delay-line filter for distortion correction of digital data after transmission by a voice line. The procedure described achieves approximately the optimal tap settings by solving a system of linear equations with a circulant matrix of coefficients. When the fast Fourier transform algorithm of Cooley and Tukey is used, the resulting quantity of computations is considerably smaller than in other known methods. Therefore, much faster equalization can be achieved.