A hands-free phone system based on a partitioned frequency-domain adaptive echo canceler

Providing means for hands-free conversation is of great interest for industry and is still a current research topic. In this paper, a partitioned frequency-domain adaptive FIR filter is applied in a hands-free phone system to provide echo compensation. It is optimally designed in such a way that it approaches the tracking behavior of the Recursive Least-Squares (RLS) algorithm, and it is combined with a new adaptive step-size control in order to cope with varying far-end/local speaker situations. Its performance is demonstrated by means of real speech signals. Assuming a loudspeaker-room-microphone impulse response duration of 3500 taps, an increase in the critical gain of 14dB has been obtained (for each phone) by using an adaptive echo canceler with 1152 taps.