Efficient FIR adaptive filter using DPCM and the sign algorithm

This correspondence introduces an adaptive filter structure that requires zero multiplications for its implementation. The primary input signal is quantized using DPCM, and the DPCM outputs are processed by a conventional adaptive filter. The filter coefficients are updated using the sign algorithm. Under the assumption that the primary and reference input signals to the adaptive filter are zero mean, wide-sense stationary, and Gaussian, we also derive theoretical results for the mean and mean-squared behavior of the filter. A simulation example demonstrating the usefulness of the filter, as well as verifying the theoretical results and comparing the multiplication free adaptive digital filter to the sign algorithm, is also presented.