Relations between the local weight distributions of a binary linear code, its extended code, and its even weight subcode are presented. In particular, for a code of which the extended code is transitive invariant and ...
详细信息
ISBN:
(纸本)0780391500
Relations between the local weight distributions of a binary linear code, its extended code, and its even weight subcode are presented. In particular, for a code of which the extended code is transitive invariant and contains only codewords with weight multiples of four, the local weight distribution can be obtained from that of the extended code. Using the relations, the local weight distributions of the (127, k) primitive BCH codes for k <= 50, the (127, 64) punctured third-order Reed-Muller, and their even weight subcodes are obtained from the local weight distribution of the (128, k) extended primitive BCH codes for k <= 50 and the (128,64) third-order Reed-Muller code. We also show an approach to improve an algorithm for computing the local weight distribution proposed before.
Biometric discretization extracts a binary string from a set of real-valued features per user. This representative string can be used as a cryptographic key in many security applications upon error correction. Discret...
详细信息
Biometric discretization extracts a binary string from a set of real-valued features per user. This representative string can be used as a cryptographic key in many security applications upon error correction. Discretization performance should not degrade from the actual continuous features-based classification performance significantly. However, numerous discretization approaches based on ineffective encoding schemes have been put forward. Therefore, the correlation between such discretization and classification has never been made clear. In this article, we aim to bridge the gap between continuous and Hamming domains, and provide a revelation upon how discretization based on equal-width quantization and linearly separable subcode encoding could affect the classification performance in the Hamming domain. We further illustrate how such discretization can be applied in order to obtain a highly resembled classification performance under the general Lp distance and the inner product metrics. Finally, empirical studies conducted on two benchmark face datasets vindicate our analysis results.
We completely characterize possible indices of quasi-cyclic subcodes in a cyclic code for a very broad class of cyclic codes. We present enumeration results for quasi-cyclic subcodes of a fixed index and show that the...
详细信息
We completely characterize possible indices of quasi-cyclic subcodes in a cyclic code for a very broad class of cyclic codes. We present enumeration results for quasi-cyclic subcodes of a fixed index and show that the problem of enumeration is equivalent to enumeration of certain vector subspaces in finite fields. In particular, we present enumeration results for quasi-cyclic subcodes of the simplex code and duals of certain Bose-Chaudhuri-Hocquenqhem codes. Our results are based on the trace representation of cyclic codes.
In this paper, we consider linear subcodes of RMr, m whose bases are formed from the monomial basis of RMr, (m) by deleting Delta K monomials of degree r where Delta K < ((m)(r)). For such subcodes, a procedure for...
详细信息
In this paper, we consider linear subcodes of RMr, m whose bases are formed from the monomial basis of RMr, (m) by deleting Delta K monomials of degree r where Delta K < ((m)(r)). For such subcodes, a procedure for computing the number ber of minimum weight codewords is presented and it is shown how to delete Delta K monomials in order to obtain a subcode with the smallest number of codewords of the minimum weight. For Delta K less than or equal to 3, a formula for the number of codewords of the minimum weight is presented. A (64, 40) subcode of RM3, 6 is being considered as an inner code in a concatenated coding system for NASA's high-speed satellite communications. For (64,40) subcodes, there are three equivalent classes. For each class, the number of minimum weight codewords, that of the second smallest weight codewords and simulation results on error probabilities of soft-decision maximum likelihood decoding are presented.
We show that any ternary Euclidean (resp. quaternary Hermitian) linear complementary dual [n, k] code contains a Euclidean (resp. Hermitian) linear complementary dual [n, k - 1] subcode for 2 <= k <= n. As a con...
详细信息
We show that any ternary Euclidean (resp. quaternary Hermitian) linear complementary dual [n, k] code contains a Euclidean (resp. Hermitian) linear complementary dual [n, k - 1] subcode for 2 <= k <= n. As a consequence, we derive a bound on the largest minimum weights among ternary Euclidean linear complementary dual codes and quaternary Hermitian linear complementary dual codes. (C) 2020 Elsevier B.V. All rights reserved.
In this correspondence, we present a technique for generation of linear subcodes of a given turbo code with better distance spectrum than the original mother turbo code, via an iterative process of trace-bit injection...
详细信息
In this correspondence, we present a technique for generation of linear subcodes of a given turbo code with better distance spectrum than the original mother turbo code, via an iterative process of trace-bit injection which minimally reduces code rate, followed by selective puncturing that allows recovery of the rate loss incurred during the trace-bit injection. The technique allows for asymptotic performance improvement of any linear turbo code. In effect, we trim the distance spectrum of a turbo code via elimination of the low distance and/or high multiplicity codewords from the output space of the code. To this end, we perform a greedy minimization of a cost function closely related to the asymptotic bit error probability (or frame error probability) of the code. This improves the performance of the code everywhere, but its main impact is a reduction in the error floor of the turbo code which is important for delay constrained applications employing short interleavers.
Let C be a binary linear code with covering radius R, and C0 a subcode of C of codimension i. An upper bound is obtained for the covering radius of C0 in terms of R and i. When C0 = {0}, the bound becomes the sphere c...
详细信息
Let C be a binary linear code with covering radius R, and C0 a subcode of C of codimension i. An upper bound is obtained for the covering radius of C0 in terms of R and i. When C0 = {0}, the bound becomes the sphere covering bound for R.
We study the symmetry group of a binary perfect Mollard code M(C,D) of length tm + t + m containing as its subcodes the codes C (1) and D (2) formed from perfect codes C and D of lengths t and m, respectively, by addi...
详细信息
We study the symmetry group of a binary perfect Mollard code M(C,D) of length tm + t + m containing as its subcodes the codes C (1) and D (2) formed from perfect codes C and D of lengths t and m, respectively, by adding an appropriate number of zeros. For the Mollard codes, we generalize the result obtained in [1] for the symmetry group of Vasil'ev codes;namely, we describe the stabilizer Sym(M(C,D)) of the subcode D (2) in the symmetry group of the code M(C,D) (with the trivial function). Thus we obtain a new lower bound on the order of the symmetry group of the Mollard code. A similar result is established for the automorphism group of Steiner triple systems obtained by the Mollard construction but not necessarily associated with perfect codes. To obtain this result, we essentially use the notions of "linearity" of coordinate positions (points) of a nonlinear perfect code and a nonprojective Steiner triple system.
This paper presents a method for evaluating the bit-error probability of a concatenated coding system for BPSK transmission over the AWGN channel, In the concatenated system, a linear Binary block code is used as the ...
详细信息
This paper presents a method for evaluating the bit-error probability of a concatenated coding system for BPSK transmission over the AWGN channel, In the concatenated system, a linear Binary block code is used as the inner code and is decoded with the soft-decision maximum likelihood decoding, and a maximum distance separable code (or its interleaved code) is used as the outer code and is decoded with a bounded distance decoding, The method is illustrated through a specific example in which the inner code is a binary (64,40,8) Reed-Muller subcode and the outer code is the NASA standard (255,223,33) Reed-Solomon code over GF(2(8)) interleaved to a depth of 5, This specific concatenated system is being considered for NASA's high-speed satellite communications, The bit-error performance is evaluated by a combination of simulation and analysis, The split weight enumerators for the maximum distance separable codes are derived and used for the analysis.
暂无评论