PERFORMANCE OF ADAPTIVE PREDICTION ALGORITHMS FOR TRELLIS-CODED QUANTIZATION OF SPEECH

This paper investigates the performance of different adaptive predicti on 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 quantizatio n (TCQ). In the work presented, we demonstrate that when trellises bas ed on feedback-free convolutional encoding circuits are employed, erro r propagation in TCQ systems is not a serious problem. Performance com parisons 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 idea l channel, a system employing an all-pole least squares lattice predic tor with pitch prediction produces reconstructed speech that is nearly indistinguishable from the original.