  Proportionate type algorithms were developed and excessively used in the echo
cancellation problems due to sparse characteristics of the echo channels. In
the past, most of the attention was paid to a particular type of proportionate
approach, which assigns step-sizes to filter coefficients proportional to the
magnitude of the corresponding coefficient. In this letter, we propose a new
proportionate type algorithm, which takes dynamic behavior of the estimated
filter coefficient into account while assigning individual step-sizes to each
coefficient. Proposed algorithm introduces an effective way to assign
individual step-sizes using the time derivatives of the filter coefficients.
Computational complexity of the proposed algorithm is similar to those of
previously proposed algorithms. Simulation results have shown the improvements
in the convergence rate achieved by the proposed algorithm.
