On Determining Optimal Reverberation Parameters for Late Residual Echo Suppression

摘要

When deploying acoustic echo cancellation systems in large rooms, using short filters may result in significant amount of residual echo caused by room reverberation. In this paper, we model the late residual echo as exponentially decaying and use a parametric IIR filter to estimate its power in the subband domain for application in residual echo suppression. Working in an offline system identification setup, the problem of finding the optimal parameters of the IIR filter is addressed, with an analysis conducted on the performance of two parameter estimation methods: output error and equation error. The late residual echo power estimates obtained using the two methods are furthermore judged using the mean squared error and the mean squared log error cost functions. Results indicate that minimizing the mean squared log error for the output error method provides accurate estimates for the late residual echo power and the reverberation decay parameter.