—Two product array codes are used to construct the (24, 12, 8) binary Golay code through the direct sum operation. This construction provides a systematic way to find proper (8, 4, 4) linear block component codes for generating the Golay code, and it generates and extends previously existing methods that use a similar construction framework. The code constructed is simple to decode.

The Assmus{Mattson theorem is a method to nd designs in linear codes over a nite eld. The purpose of this paper is to give an analogue of this theorem for Z 4 -codes by using the harmonic weight enumerator which is introduced by Bachoc. This theorem can nd some 5-designs in the lifted Golay code over Z 4 which were discovered previously by other methods. Index Terms { Z 4 -codes, Assmus{Mattson...

It is not known whether there exist polynomials with plus and minus one coefficients that are almost constant on the unit circle (called ultraflat). Extensive computations described in this paper strongly suggest such polynomials do not exist, and lead to conjectures about the precise degree to which flatness can be approached according to various criteria. The evidence shows surprisingly rapid...

We describe a method of constructing a sequence of phase coded waveforms with perfect autocorrelation in the presence of Doppler shift. The constituent waveforms are Golay complementary pairs which have perfect autocorrelation at zero Doppler but are sensitive to nonzero Doppler shifts. We extend this construction to multiple dimensions, in particular to radar polarimetry, where the two dimensi...

Let E1 be the near hexagon on 729 points related to the extended ternary Golay code. We prove in an entirely geometricway that the generating and embedding ranks ofE1 are equal to 24. We also study the structure of the universal embeddinge of E1. More precisely, we consider several nice subgeometries A of E1 and determine which kind of embeddingeA is, whereeA is the embedding of A induced by...

Coding theory is the subject which is concerned with how information can be sent over a noisy channel. A code then is a collection of codewords which are strings of a fixed number of letters from an alphabet. Some of these strings are codewords others are not. When a codeword is sent over a channel there is a probability less than /2 that each letter in the codeword will be changed, thus introd...

Recently Golay complementary sets were shown to exist in the subsets of second-order cosets of a q-ary generalization of the first-order Reed–Muller (RM) code. We show that mutually orthogonal Golay complementary sets can also be directly constructed from second-order cosets of a q-ary generalization of the first-order RM code. This identification can be used to construct zero correlation zone ...

Automorphisms of order 2p in binary self-dual extremal codes of length a multiple of 24 Abstract Let C be a binary self-dual code with an automorphism g of order 2p, where p is an odd prime, such that g p is a fixed point free involution. If C is extremal of length a multiple of 24 all the involutions are fixed point free, except the Golay Code and eventually putative codes of length 120. Conne...