A novel multipath matrix algorithm for exact room response identification in stereo echo cancellation

Stereo echo cancellation is a key technique for solving the echo problem in modern teleconferencing systems. There is a fundamental problem in stereo echo cancellation - the misalignment between the converged filter weights and the real room impulse responses. Most existing works explain the misalignment problem by a conceptual stochastic equation, and no studies have investigated the closed-form of the final weights in a stereo echo canceller. We formulate a governing equation, multipath matrix equation (MME) to provide a systematic mathematical approach for the stereo echo cancellation system. Several phenomena of the stereo normalized least mean squares (NLMS) algorithm can be explained by using the above equation. Furthermore, we propose a new cancellation algorithm - multipath matrix algorithm (MMA). It keeps the simplicity of NLMS and can find out the real room impulse responses to exhibit better performance.