MULTISTAGE TRELLIS-CODED QUANTIZATION (MS-TCQ) DESIGN AND PERFORMANCE

Multistage trellis coded quantisation (MS-TCQ) is developed as a const rained trellis source coding technique for successive refinement of in formation. The authors study the performance of two-stage trellis code d quantisers for Gaussian and uniform memoryless sources. Problems of appropriate trellis selection, output alphabet selection, and stage-by -stage design of the codebooks are addressed. Stagewise optimisation i s done using the generalised Lloyd algorithm. Comparisons with two-dim ensional multistage vector quantisation (MSVQ) indicate that up to 1.6 dB performance improvement can be achieved by using MS-TCQ. Another al gorithm is also presented for the joint design of the stage codebooks to optimise the overall performance. It is shown that another 0.5dB im provement can be achieved by employing the joint design algorithm.