Differential coding of speech LSF parameters using hybrid vector quantization and bidirectional prediction

This article presents a new strategy to encode the LP (linear predictive) short-time spectral envelope (STSE) of speech. A better reconstruction of the STSE is achieved by modifying the usual trade-off between the transmission rate of the LP parameters and the performance of the quantization algorithm. A differential coding based on bidirectional prediction and hybrid vector quantization is used to compensate the increase in transmission rate. Simulation results show the effectiveness of this coding strategy.