Adaptive echo canceller employing DM encoding

The letter presents an echo canceller employing both delta modulation (DM) and a least-mean-square (LMS) adaptive filter. An adaptive filter operating on a DM binary output sequence attempts to model the echo path. This tandem connection can significantly reduce the hardware complexity. The proposed scheme appears to have considerable potential in telecommunications as the results are comparable to those obtained from the classical echo canceller with PCM.