Implementation of Acoustic Echo Cancellation through Adaptive Filtering Algorithms in MATLAB

Acoustic Echo Cancellation through Adaptive Filtering Algorithms

Abstract

Acoustic echo cancellation (AEC) is crucial for hands-free communication systems to mitigate echoes caused by microphone-loudspeaker coupling. This study presents a software-based AEC system implemented in MATLAB, leveraging adaptive filtering algorithms, specifically Least Mean Squares (LMS) and Normalized Least Mean Squares (NLMS), to achieve real-time echo suppression. Unlike conventional hardware-based methods reliant on Digital Signal Processors (DSP) and Very Large Scale Integration (VLSI) processors, the proposed approach provides a cost-effective and flexible alternative without sacrificing performance. Key contributions: a novel step-size adaptation technique for LMS/NLMS, enhancing convergence stability and computational efficiency. An optimized noise gate device for superior residual echo suppression, ensuring improved speech clarity. Comprehensive performance evaluation of LMS and NLMS algorithms under dynamic acoustic conditions, including real-world testing across varying noise levels and speaker-microphone distances. Results demonstrate that the proposed software-based solution achieves faster convergence, reduced computational complexity, and effective suppression of acoustic echoes, offering a scalable alternative to expensive DSP-based implementations.