Sub-band IIR acoustic echo canceller

In teleconferencing systems the echo can be very long. A direct FIR implementation of the echo canceller often requires more than 2000 taps. One approach is to process the signal in sub-bands providing a separate FIR echo canceller for each band. We propose the use of an IIR filter in each sub-band adapted by a variant of the Steiglitz-McBride identification scheme instead of the classical adaptive FIR filters. Experimental results and computer simulations show that the proposed IIR sub-band echo canceller performs better then the equivalent FIR counterpart.