This paper studies the concatenation of turbo codes and Reed-Solomon (RS) codes. The error patterns of turbo codes are first analyzed. Since error patterns of turbo codes are much different than those of convolutional codes, the design rules for a matched interleaver between turbo codes and RS codes are provided. As an application to digital video broadcasting by satellite (DVB-S), the performance of Forney interleavers with different spreading abilities is studied for a fixed turbo code. For a (34,6) Forney interleaver, the performance of turbo codes with different block sizes is also studied. A delay and performance tradeoff can be made via simulation results.

It is well known that trellis lossy source codes have better performance/complexity tradeoff than block codes, as shown by simulations. This makes the trellis coding technique attractive in practice. To get a better understanding of this fact, this paper studies the redundancy of trellis coding for memoryless sources and compares it with a similar result for block codes.

The synchronization recovery property of variable-length (VL) codes has been extensively studied. In the paper, the mean error propagation length (MEPL) and the variance of error propagation length (VEPL), which are the secondary performance criteria of a VL code, are introduced to measure the synchronization recovery capability of a VL code. For the same probability distribution, there exist many different VL codes which have the same redundancy as the Huffman code but quite different MEPLs and VEPLs. To find one of the VL codes which has the minimum MEPL is a very difficult problem. We present two design algorithms for finding minimum-redundancy VL codes with short MEPL and VEPL. These two algorithms are simple and have the property that the codewords are assigned one by one. The efficiency of the algorithms are tested extensively by comparing the algorithms with known construction methods available in literature. Actually, VL codes obtained by the two algorithms outperform almost all codes available.

Multiple description schemes for trellis coded vector quantizers are introduced. For these schemes, the Viterbi algorithm provides an optimal path for encoding and the design procedure utilizes the generalized Lloyd algorithm for suboptimal codebooks. The schemes are generalization of Jafarkhani and Throkh (see ICIP '98, Proceedings. of International Conference on Image Processing, vol.1, p.669-673,1998 and IEEE Transactions on Communications, vol.47, no.6, p.799-803, 1999) method in both temporal and spatial senses. A lower bound on rate-distortion region for more than three descriptions is given. The lower bound is a generalization of Ozarow's (1980) achievable region for a two channel and three description scheme.

Space-time convolutional codes have been shown to provide improved performance for high data rate transmission over fading channels through combined space diversity and coding gain. However, there are still some questions on how to design the codes in binary or discrete domain to achieve these gains in the complex domain of baseband-modulated signals. In this paper, we first consider the effect of minimum distance in the space-time codes, then propose a new efficient design method which is based on the upper and lower bounds of the coding gain. The simulation result shows that the new approach allows a fast search for optimal space-time convolutional codes for many practical problems.