A jointly optimized adaptive recursive echo canceller with adaptive equalizer and line enhancer

The adaptive recursive echo canceler (AREC) can match a typical echo path with fewer weight coefficients than the adaptive transversal echo canceler (ATEC). Therefore, the AREC has a higher convergence rate and smaller adaptation noise than the ATEC. On the other hand, the AREC has a tendency to instability during the adaptation process if any pole moves outside the unit circle. A novel structure of AREC, equalizer, and line enhancer is introduced. The proposed structure is always stable and the interference of the far-end signal is highly reduced. Consequently, the performance of the AREC is significantly improved with a moderate computation complexity.<>