An adaptive IIR echo canceller combining output-error and equation-error criteria

An echo canceller structure which permits the combined use of the equation error and the output error criteria in the adaptation of the coefficients is presented. A method is described for the smooth transition between the two criteria in such a way that the advantages of both are retained and their drawbacks are eliminated. Further improvement is obtained by using lattice structures in the realization of some of the canceller´s blocks. Computer simulation results are presented which confirm the superior performance of the echo canceller with respect to other realizations