DSP上實現偵測雙邊對話之適應性回音消除器

Abstract

An adaptive echo canceller(EC)suffers a significant degradationwhen double talk arises.In this thesis, power level detection is used to detect double talk.We will try to estimate the threshold values of ERL and EPL for double talkdetector( DTD).When double talk is detected, the adaptive EC is frozen and afilter coefficients-restore method is used to assureecho cancellation quality.We will analyze the adaptive EC performance using this method and its effect on DTD.In addition, we propose a new power-weight method to aid DTD.For low-cost fixed point adaptive EC algorithm, we will perform its roundoff analysis.The above methods will be implemented on fixed-point TMS320C541 DSP.Finally, computer simulationsare provided to verify our analysis.