Bose and Chaudhuri (1960) have introduced a class of binary errorcorrecting codes of block length 2 ~ 1, m = 2,3,• • which we refer to here as B-C codes. An efficient decoding scheme has been devised for them by Peterson (1960), and generalized to the natural extension of the B-C Codes to codes in pm symbols by D. Gorenstein and N. Zierler (1960). Two further properties of B-C codes are establi...

In prefix coding over an infinite alphabet, methods that consider specific distributions generally consider those that decline more quickly than a power law (e.g., Golomb coding). Particular power-law distributions, however, model many random variables encountered in practice. For such random variables, compression performance is judged via estimates of expected bits per input symbol. This corr...

In this paper a class of linear error-correcting block codes is investigated. These quasicyclic codes are closely related in structure to cyclic codes although they are not nearly as well understood. I t is shown that an important subclass of the class of cyclic codes is almost equivMent to quasicyclic codes. Also, a short computer generated list of the best quasicyclic codes of rate 1⁄2 is giv...

Due to the editorial process, there may be slight discrepancies between this version and the published one. Abstract|The problem of minimizing the vertex count at a given time index in the trellis for a general (nonlinear) code is shown to be NP-complete. Examples are provided that show that 1) the minimal trellis for a nonlinear code may not be observable, i.e., some codewords may be represent...

A novel trellis design technique for both block and convolutional codes based on the Shannon product of component block codes is introduced. Using the proposed technique, structured trellises for block and convolutional codes have been designed. It is shown that the designed trellises are minimal and allow reduced complexity Viterbi decoding. Zndex Terms-Linear codes, trellis structure, product...

The performance of a Turbo code depends on the interleaver design. There are two major criteria that can be considered in the design of an interleaver. Distance spectrum properties of the code and the correlation of the extrinsic information with the input data are the two major criteria in designing an interleaver. This paper describes a new interleaver design based on these two criteria. Simu...

The function N(r; ; dfree), defined as the maximum n such that there exists a binary convolutional code of block length n, dimension n r, constraint length , and free distance dfree, is studied. For dfree 2 f3; 4g, codes are obtained from simple constructions that determine N(r; ; dfree) for all positive integers and r. Codes with minimum Hamming distance dfree 5 are found by computer search. A...

Practical storage systems often adopt erasure codes to tolerate device failures and sector failures, both of which are prevalent in the field. However, traditional erasure codes employ device-level redundancy to protect against sector failures, and hence incur significant space overhead. Recent sector-disk (SD) codes are available only for limited configurations due to the relatively strict ass...

This paper studies turbo-like coded modulation in the block-fading channel. In particular we show that the performance of such coded modulation schemes is close to the information outage probability of the channel for any block length, as opposed to standard coded modulation schemes based on trellis-terminated convolutional codes. For large block length, asymptotic performance of the proposed s...

We suggest a new algorithm of the block encoding that can be implemented in such a way that block of several letters is coded using almost the same number of operations as a usual code uses for one letter. The new algorithm is based on methods of grouping of alphabet letters suggested recently in [5], [6], which combines letters from a large alphabet into a small number of subsets without an es...