Unconstrained frequency-domain adaptive filter

An unconstrained frequency-domain least mean-squares (UFLMS) algorithm is presented. The algorithm is based on the "overlap-save" technique used in frequency-domain filtering. The proposed algorithm converges to the Wiener solution without the time-domain constraint on the impulse response as proposed by Ferrara. For a large number of taps ( ), the UFLMS algorithm offers a significant reduction in computation. Another advantage is its fast convergence for highly correlated input signals. The performance of the algorithm is illustrated by a simulation.