A GSC-type structure for FIR-IFIR hybrid echo canceling

This paper presents a GSC-type structure for the FIR-IFIR hybrid echo canceller and the optimum filters are defined. The measure of echo cancellation performance is presented, which is a function of the input signal correlation, of the sparseness degree and of the interpolator parameters. Furthermore, the LMS algorithm for updating the filter coefficients in adaptive systems is also developed. Simulation results illustrate the effectiveness of the new approach to this FIR-IFIR hybrid filtering problem for both white and colored input noise.