Tap.leakage Applied to Echo Cancellation

This study presents a tap-leakage adjustment algorithm to control the tap drifting problem in an adaptive echo canceller. A nonrecursive transversal filter structure and stochastic gradient adaptation algorithm are first studied. On the basis of these studies, the effect of tap drift when the input spectrum does not cover the full band is presented. The tap-leakage algorithm, which has been used in fractional spaced equalizers and speech coding is introduced. In this thesis, the tap-leakage algorithm is applied to an echo canceller. In addition, a least-squares lattice filter is proposed to overcome slow convergence problems due to narrowband inputs. Finally, the simulation results of the stochastic gradient, tap-leakage and least-squares lattice algorithms are studied.