Advances in Error Control Coding Techniques

In the past decade, a significant progresshas been reported in the field of error control coding. In particular, the innovation ofturbo codes and rediscovery of LDPC codes have been recognized as two significant breakthroughs in this field. The distinct features of these capacity approaching codes have enabled them to be widely proposed and/or adopted in existing wireless standards. Furthermore, the invention of space time coding significantly increased the capacity of wireless systems and these codes have been widely applied in broadband communication systems. Recently, new coding concepts, exploiting the distributed nature of networks, have been developed, such as network coding and distributed coding techniques. They have great potential applications in wireless, sensor, and ad hoc networks. Despite recent advances, many challenging problems still remain. This special issue is intended to present the state-of-the-art results in the theory and applications of coding techniques. The special issue has received twenty six submissions, and among them, thirteen papers have been finally selected after a rigorous review process. They reflect recent advances in the area of error control coding. In the first paper, " Structured LDPC codes over integer residue rings, " Mo and Armand designed a new class of low-density parity-check (LDPC) codes over integer residue rings. The codes are constructed based on regular Tanner graphs by using Latin squares over a multiplicative group of a Galois ring, rather than a finite field. The proposed approach is suitable for the design of codes with a wide range of rates. One feature of this type of codes is that their minimum pseudocodeword weights are equal to their minimum Hamming distances. The next two-part series of papers " Differentially encoded LDPC codes—Part I: special case of product accumulate codes " and " Differentially encoded LDPC codes— Part II: general case and code optimization, " by J. Tiffany Li, study the theory and practice of differentially encoded low-density parity-check (DE-LDPC) codes in the context of noncoherent detection. Part I studies a special class of DE-LDPC codes, product accumulate codes. The more general case of DE-LDPC codes, where the LDPC part may take arbitrary-degree profiles, is studied in Part II. The analysis reveals that a conventional LDPC code is not fitful for differential coding, and does not in general deliver a desirable performance when detected noncoherently. Through extrin-sic information transfer (EXIT) analysis and a modified " convergence constraint " density evolution (DE) method, a characterization of the …