This paper irrvestigates the performance of different adaptive prediction. algorithms for use in a low delay, high-quality speech coder at -16 kbit/s. The system to be studied is based on trellis coded quantization (TCQ). In the work presented, we demonstrate that when trellises based on feedback-free convolutional encoding circuits are employed, error propagation in TCQ systems is not a serious problem. Performance comparisons are made using a fixed predictor and four different adaptive predictors. Informal listening, tests reveal that the encoded speech, is of good communications quality at an error rate of 10–3. In an ideal channel, a system employing an all-pobe. least squares lattice predictor with pitch prediction produces reconstructed speech that is nearly indistinguishable from the original.
ASJC Scopus subject areas
- Electrical and Electronic Engineering