A fast codeword search algorithm for the line spectrum frequency vector quantizer of the G.729

The line spectrum frequency vector quantization of the G.729 using a two-stage vector quantizer. The first stage is a 10-dimensional vector quantization, full search algorithm is used to obtain the codebook vector, but it requires large computational load and long search time. In this paper, we study several fast search algorithms and propose a fast codebook search method, which is based on sum value and variance algorithm. The algorithm uses pre-ordered codebook and the efficient elimination criteria, which greatly reduces the code word search range. Test results show that it is a fast and efficient codeword search algorithm, can significantly reduce the codeword search time and increase coding speed, and speech still maintains the same quality.