Conjugate gradient algorithm for adaptive echo cancellation

The advent of high-performance digital signal processors has spurred the development of sophisticated algorithms for adaptive filtering which are finding application in many diverse areas. Adaptive echo cancelers, which are employed to preserve voice quality in telecommunication systems, demand fast convergence to minimize the subjective effects of uncancelled echo at the beginning of a conversation. The LMS adaptive algorithm, which is simple to implement, suffers from slow convergence. The RLS algorithm, which provides faster convergence, is prohibitively expensive to implement. It is shown that application of the conjugate gradient adaptation algorithm for echo cancellation results in fast convergence with reasonable complexity