RESIDUAL ECHO SIGNAL IN CRITICALLY SAMPLED SUBBAND ACOUSTIC ECHO CANCELERS BASED ON IIR AND FIR FILTER BANKS

The residual echo signal characteristics of critically sampled subband acoustic echo cancellers are analyzed, Far finite impulse response (F IR) filter banks, the residual echo signal usually has a relatively br oad spectral nature around the subband edges, The residual echo signal of power symmetric infinite impulse response (PS-IIR) filter banks, o n the other hand, has very narrowband spectral components around the s ubband edges, These components can be efficiently removed with PS-IIR notch filters that integrate neatly into the filter banks without intr oducing perceptually noticeable degradation to the near-end speech, Th is solution has very low computational complexity and does not impinge on the system performance, Simulation studies with recordings from th e cockpit of a car, based on a fast QR least-squares adaptive algorith m, demonstrate the potential of this approach for a practical AEC syst em.