Joint Intraframe and Interframe Coding of Line Spectrum Frequency
Nan Zhang · Jisuanji fangzhen · 2013
In order to reduce speech coding bit rate,the advantages of intra-frame and inter-frame correlation of Line Spectrum Frequency(LSF) were taken to design a prediction model as well as a simplified prediction model based on partial least squares(PLS) algorithm.According to the U/V pattern of super-frame structure,the proposed algorithms could predict a LSF not only by some LSFs from the previous and next frame,but also by its exactly previous LSF in the same frame.Simulation results show that the PLS model and its simplified model can both effectively reduce the dynamic range of LSF.The PLS model is more accurate,while,the simplified model performs better in computational load and complexity.Using SVQ to split the prediction error vector into two sub-vectors of dimensions(4,6),can get an average spectrum distortion about 1 dB at 7 bits/frame,whose bit rate are less than 2.4 kbps MELP coding standard 18 bits/frame.