Adaptive acoustic echo cancellation based on FIR and IIR filter banks

We investigate various subband AEC systems in real handsfree situation, including FIR and IIR analysis and synthesis QMF filter banks in a polyphase structure. The adaptation in the subbands is performed by the affine projection algorithm in comparison to the NLMS algorithm. The IIR filters are superior to FIR filters in the sense that they lead to low signal delay and sharp frequency separation. Furthermore the computational complexity is greatly reduced by the use of IIR filters. The results show that splitting the signal into more subbands has advantages. Both wideband and narrowband speech signals have been evaluated