Abstract: A Predictor is described which is based on a modified RLS (recursive least squares) algorithm. The modifications prevent divergence and accuracy problems when fixed point implementation is used.

Abstract: An encoder for encoding a first digital signal representative for a first channel and a second digital signal representative for a second channel is described. The encoder comprises cascaded intra-channel prediction elements for compressing the first digital signal and the second digital signal based on intra-channel correlation and an inter-channel prediction element for compressing the first digital signal and the second digital signal based on inter-channel correlation.

Abstract: A method of coding speech is disclosed in which the speech signal is sampled and divided into a plurality of frames upon which multi-band excitation analysis is performed to derive a fundamental pitch, a plurality of voiced/unvoiced decisions and amplitudes of harmonics within the bands. The harmonic amplitudes are split into a first group of a fixed number of harmonics and a second group of the remainder of harmonics and these are separately transformed using the Discrete Cosine Transform for the first group and Non-Square Transform for the second group, the resulting transform coefficients being vector quantized to form a plurality of output indices. A decoding method and apparatus for performing both encoding and decoding methods are also disclosed.