Adaptive reference echo cancellation with memory structure

Abstract

A new approach, adaptive reference echo cancellation (AREC) with memory structure, is proposed, which can be used in a user/network interface for ISDN basic rate access, or in an other application, two-wire full-duplex transmission. As compared with a conventional (zero-reference) echo cancellation, the new approach, with a larger step-size, allows adaption of the echo canceller and the receiver to converge to a smaller residual echo. The approach is not sensitivity to non-linearity and is simple and feasible to implement in LSI, because of use of a lookup table structure. The authors analyse in detail the convergence performance of the AREC, and gives a computer simulation. The results shows that the new approach is preferable to the conventional ones.<>