Nonlinear acoustic echo cancellation using orthogonal polynomial

Abstract

In order to compensate the nonlinear distortion in the hands -free telephones or teleconferencing system, a memoryless power- series-based polynomial NLMS adaptive filter can be used to cancel nonlinear acoustic echo. Conventional polynomial model employs a power-series expansion. In this paper we propose an orthogonal polynomial adaptive filter to accelerate the convergence rate of the nonlinear adaptive filter. The convergence rates of residual echo power for both power-series and orthogonal polynomials are derived analytically. Computer simulations justify our analysis and show the improved performance of the proposed nonlinear acoustic echo canceller.