Study of a Fast Method to Calculate Inverse Filters

In certain systems it is very important to calculate quickly an inverse filter that has a large number of taps. Several approaches to solving normal equations are investigated. One fast method uses conjugate gradients in the frequency domain. To enhance this method a fast method that calculates only linear convolutions in conjugate gradients by FFT is proposed. Simulation results show that the sum of the squares of the residual errors of our method is as low as that of the Levinson algorithm, which is slower than the method proposed.