ECHO CANCELLER WITH REDUCED ARITHMETIC PRECISION.

Abstract

The paper introduces a new echo canceller: the controlled gain echo canceller (CGEC) which uses an adaptive gain control at the output of the classical echo canceller (CEC). A feedback loop permits approximate regulation of the front-edge (CEC) output power at a nominal level, independently of the echo and far-end signal levels. By this means, the precision required for adaptation is reduced to a minimum value. The analysis of adaptation, convergence, residual echo power, and computational complexity is given for the CGEC and compared to the similar quantities in a CEC; computer simulation results are presented.