Patent ID: 7769581

Claim:
A method of coding an audio or speech signal using a codebook search of a codebook, comprising: dividing said codebook into a plurality of codebook groups, where the codebook comprises a plurality of code vectors for vector quantization of a signal vector representing a set of signal values of said audio or speech signal; simultaneously determining a plurality of optimal group code vectors, each of which corresponds to one of said plurality of codebook groups by performing a comparison of the plurality of code vectors within said codebook search to determine the optimal code vector, wherein said comparison is based on cross multiplication expression C t *E best ><E t *C best , calculated in parallel for every vector, which is based on fixed point operations performed, wherein C t is a cross term corresponding to a t-th code vector and C best is the cross term corresponding to a temporarily best code vector, and wherein E t is a energy term corresponding to said t-th code vector and E best is the energy term corresponding to said temporarily best code vector; determining an optimal code vector of said codebook from said plurality of optimal group code vectors; and outputting the optimal code vector, wherein said determining of said optimal code vector among said plurality of optimal group code vectors comprises evaluating an index of each optimal group code vector uniquely identifying each optimal group code vector within said codebook, wherein the evaluating the index comprises comparing the index of each optimal group code vector with indices of other optimal group code vectors; wherein the comparing of the index of each optimal group code vector is different from a comparison between the group code vectors; and wherein the evaluating the index further comprises selecting a code vector with a smaller index as a result of comparing the indices of the optimal group code vectors if equality regarding the cross multiplication expression occurs in a comparison between optimal group code vectors.