Complexity reduction for FS-1016 with multistage search
M. Mauc, Geneviève Baudoin, Milan Jelinek · 2002
CELP speech coders have proved to be efficient for the coding of speech at medium and low bit rates. The NSA has recently introduced the Federal Standard 1016, CELP speech coder at 4800 bps. We propose two algorithms that reduce the complexity of this coder by a factor 2. The first algorithm uses the particular structure of the standardised code book to simplify the calculation of the cross-correlation term. The second algorithm is a multistage method by subsampling that eliminates nonrelevant code book sequences for the calculation of the energy term.>