Efficient decomposition in noise and periodic signal waveforms in

Abstract

A low-complexity method and apparatus for performing signal decomposition in a low bit-rate WI speech encoder. A time-ordered sequence of sets of time-domain parameters is generated based on samples of a speech signal to be coded, each set of time-domain parameters corresponding to a waveform characterizing the speech signal. A cross correlation is then performed between two or more of said sets of time-domain parameters to produce a set of signals which represents relatively high rates of evolution of characterizing waveform shape across the time-ordered sequence of sets. Finally, the speech signal is coded based on the produced set of signals. A set of signals which represents relatively low rates of evolution of characterizing waveform shape across the time-ordered sequence of sets may also be produced. In this case, a time-ordered sequence of sets of frequency-domain parameters is also generated based on the samples of the speech signal to be coded, and an average of two or more of these sets of frequency-domain parameters is then computed. A set of signals which represents relatively low rates of evolution of characterizing waveform shape across the time-ordered sequence of sets is then produced based on the computed average, and the speech signal is then coded further based on this produced set of signals as well.