A study of joint source-channel coding of LSP parameters for wideband speech coding

A study of combined source and channel coding applied to LSP parameters in wideband speech coding is presented. The traditional approach to protect against channel errors is to increase the bit-rate for channel coding, decreasing the bit-rate of the source coding according the channel conditions. Joint source-channel coding is an alternative that provides a technique to mitigate channel errors without an increase of the bit-rate due to channel coding. This paper presents a study of channel optimized vector quantizer and channel optimized matrix quantizer applied to line spectral pairs (LSP) parameters in wideband speech coding. Gaussian and slow-fading Rayleigh channels are considered and GMSK (Gaussian minimum shift-keying) is used as the modulation technique. In addition, for comparison purposes, the performance of other schemes (split vector quantization, split matrix quantization and split multistage vector quantization) for quantizing the LSP parameters are evaluated.