Performance of pitch synchronous multi-band (PSMB) speech coder with error-correction coding

Abstract

A novel speech coding algorithm, named pitch synchronous multiband-excitation (PSMB), is presented in this paper. It uses the multiband excitation (MBE) model to generate a representative pitch-cycle waveform (PCW) for each frame. The representative PCW of a frame is encoded using two out of three codebooks depending upon whether the frame is related or unrelated to the previous frame. The PSMB coder operating at 4 kbps outperforms the Inmarsat 4.15 kbps IMBE coder by a clear margin. The sensitivity of the source bits to channel errors is extensively investigated, All the source bits can be classified into several groups according to their perceptual significance. The BCH codes and punctured convolutional (PC) codes are used to protect the perceptually significant source bits in order to minimize the effect of channel errors on the performance of the proposed coder.