IIR echo canceller using a dual error criterion and incorporating a lattice structure

A new recursive echo canceller (EC) for data transmission is proposed, where the output-error criterion and the equation-error criterion are used simultaneously. The combination of these two error criteria allows a fast initial convergence and leads to error surfaces with a single (global) minimum corresponding to unbiased parameter estimates, provided that the EC structure is not underspecified. The proposed EC includes an all-pole lattice structure, which greatly simplifies the control of the poles position to ensure stability. The transversal-to-lattice conversion is used to update the reflection coefficients, but the total amount of signal processing is reduced, because those coefficients need not be updated at every iteration. The results of a computer simulation show that the new echo canceller, when compared to commonly used conventional structures, can give a better performance. (C) 1997 Elsevier Science B.V.