We determine the structure of cyclic codes over Z4 for arbitrary even length giving the generator polynomial for these codes. We determine the number of cyclic codes for a given length. We describe the duals of the cyclic codes, describe the form of cyclic codes that are self-dual and give the number of these codes. We end by examining specific cases of cyclic codes, giving all cyclic self-dual...

Absfracf-A construction is given .that combines an (n, MI, &) code with an (n, Mt, de = [+(dl + l)]) code to form a (an, M1M2, dl) code. This is used to construct a new family of nongroup singleerror correcting codes of all lengths n from 2’” to 3 . 2m-1 1, for every wz 2 3. These codes have more codewords than any group code of the same length and minimum distance. A number of other nongroup c...

When a convolutional code is used to provide forward error correction for packet data transmission, the standard performance measures of convolutional codes, i.e., bit error rate and first-event error rate, become less useful. Instead we are interested in the average probability of block (or packet) error. In this paper a modified transfer function approach is used to obtain a union bound on th...

It is possible for a linear block code to provide more protection against errors for selected mess~ge positions than is guaranteed by the minimum distance of the code. Codes having this property are called Linear Unequal Error Protection (LUEP) codes. In this report the optimal encoding of LUEP codes is discussed and bounds on the length of a code that ensures a given unequal error protection a...

LCD codes are linear codes that intersect with their dual trivially. Quasi-cyclic codes that are LCD are characterized and studied by using their concatenated structure. Some asymptotic results are derived. Hermitian LCD codes are introduced to that end and their cyclic subclass is characterized. Constructions of QCCD codes from codes over larger alphabets are given.

This paper present the construction cyclic isodual codes over finite fields and finite chain rings. These codes are monomially equivalent to their dual. Conditions are given for the existence of cyclic isodual codes. In addition, the concept of duadic codes over finite fields is extended to finite chain rings. Several constructions of isodual cyclic codes and self-dual codes are given.

This paper gives two lossless speech compression schemes Hamming correction codes compressor (HCCC) and Systematic Linear Block Code Compressor (SLBC) based on error correcting Hamming code and systematic linear block codes respectively. Hamming codes are a family of linear errorcorrecting codes that can detect up to two-bit errors or correct one-bit errors. Systematic linear block code is any ...

Complex orthogonal designs (CODs) are used to construct space-time block codes. COD Oz with parameter [p, n, k] is a p × n matrix, where nonzero entries are filled by ±zi or ±z ∗ i , i = 1, 2, . . . , k, such that O H z Oz = (|z1| 2 + |z2| 2 + . . . + |zk| )In×n. Define Oz an M-type COD if and only if Oz does not contain submatrix (

Complex orthogonal designs (CODs) are used to construct space-time block codes. COD Oz with parameter [p, n, k] is a p × n matrix, where nonzero entries are filled by ±zi or ±z ∗ i , i = 1, 2, . . . , k, such that O H z Oz = (|z1| 2 + |z2| 2 + . . . + |zk| )In×n. Define Oz a first type COD if and only if Oz does not contain submatrix (

We consider the problem of classification of optimal ternary constantweight codes. We use combinatorial and computer methods to find inequivalent codes for some cases for 3 ≤ d ≤ n ≤ 9.