Echo cancellation using a two-stage block LMS algorithm (ISDN)

A two-stage block least-mean-square (LMS) algorithm which can be used in data echo cancellation to realize full-duplex digital data full-duplex transmission is proposed. The block LMS algorithm is implemented in two stages where there is an individual convergence factor at each stage. The convergence factor is changed according to the sign correlation between the echo signal and the error signal during the convergence process. The convergence property of the algorithm is investigated. Computer simulation results are given to verify the performance improvement. The computation saving is achieved because the coefficients are updated for each block, and it also allows rapid convergence. Therefore, the two-stage block LMS algorithm is a better choice than the conventional LMS algorithm in data echo cancellation.<
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