A low-complexity adaptive echo canceller for xDSL applications

A finite impulse response (FIR)-based adaptive filter structure is proposed for echo cancellation in xDSL applications. The proposed algorithm consists of an FIR filter, a cascaded interpolated FIR filter, and a tap-weight overlapping and nulling scheme. This filter requires low computational complexity and inherits the stable characteristics of the conventional FIR filter. Simulations show that the proposed echo canceller can effectively cancel the echo up to 73.4 dB [for a single-pair high-speed digital subscriber line (SHDSL) system]. About 55% complexity reduction can be achieved compared with a conventional FIR filter.