Abstract: A multi-pulse excitation linear-predictive speech coder operates in accordance with an analysis-by-synthesis method for determining the excitation. The coder (10) comprises an LPC-analyzer (11), a multi-phase excitation generator (13), means (12, 14) for forming an error signal representative of the difference between an original speech signal (s(n)) and a synthetic speech signal (s(n)), a filter (15) for perceptually weighting the error signal and means (16) responsive to the weighted error signal (e(n)) for generating pulse parameters controlling the excitation generator (13) so as to minimize a predetermined measure of the weighted error signal. The LPC-parameters and the pulse parameters of the excitation signal (x(n)) are encoded for efficient storage or transmission.

Abstract: A multipulse excitation signal, as a better approximation than a single-pulse excitation signal, searches for a kth pulse which minimizes either a difference between a synthesized and a reference signal, or a distance between a multipulse excitation signal and a residual signal. The search uses an averaging function M.sub.k (n) of a weighted error signal.