Robust quantization of LPC parameters for speech communication over noisy channel

In this paper, an optimized trellis coded vector quantization (OTCVQ) system designed for efficient and robust coding of LSF spectral parameters is presented. The aim of this system, called at the beginning ldquoLSF-OTCVQ Encoderrdquo, is to achieve a low bit rate transparent quantization of the FS1016 LSF parameters. Once the effectiveness of the LSF-OTCVQ encoder was proven in the case of ideal transmissions over noiseless channel, we were interested after in the improvement of its robustness for real transmissions over noisy channel. To protect implicitly the transmission indices of the LSF-OTCVQ encoder incorporated in the FS1016, we used a joint source-channel coding carried out by the channel optimized vector quantization.