Performance evaluation of a DSP-based teleconferencing system

Simulation and real time results associated with acoustic and line echo cancellation for a full-duplex teleconferencing system are presented. Both broadband (conventional) and subband finite impulse response (FIR) adaptive acoustic echo cancellers are considered. In subband scheme, quadrature mirror filters (QMF) are employed in order to construct an eight subband acoustic echo canceler. The normalized mean square (NLMS) is employed for updation of adaptive filter coefficients. Real time digital signal processing is conducted on a floating-point DSP chip in order to assess the dB cancellation of acoustic echo and line echo cancellers.<
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