Spectrum quantisation using two-dimensional multiple type frame segmentation

An efficient spectrum quantisation method using two-dimensional multiple type frame segmentation (2D-MTFS) is proposed. Conventional methods generate redundant spectral information or spectral distortion using a fixed update rate for LSP parameters, independent of the order of coefficients and the phonetic context. The proposed method optimises the update rate of each LSP parameter by various types of two-dimensional frame segmentation. Simulation results show that the proposed method generates a less distorted spectrum with fewer bits than with the conventional method. Transparent quantisation is achieved at 1275 bit/s using split vector quantisation