This work is dedicated to concurrent error detection (CED) systems synthesis together with a complete concurrent self-checking structure based on the Boolean complement method. The authors share the view of the CED sy...
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(纸本)9781509056484
This work is dedicated to concurrent error detection (CED) systems synthesis together with a complete concurrent self-checking structure based on the Boolean complement method. The authors share the view of the CED systems with a complete self-checking structure designed by the Boolean complement method and based on the constant-weight code "2-out-of-4". Within those systems logical accessories are installed for the purpose of avoiding the choice of operating vectors value which shall simplify the CED systems design process. The minimum number of operating vectors to be defined per the CED systems which should guarantee the entire variety of testing combination per the Boolean complement block as well as per the testing code "2-out-of-4".
A new approach to organizing testing of combinational devices is described;the approach implies initial compression of signals from working outputs of the test object to the binary four-digit vector and its subsequent...
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A new approach to organizing testing of combinational devices is described;the approach implies initial compression of signals from working outputs of the test object to the binary four-digit vector and its subsequent transformation to the code word of the constant-weight "1-out-of-4" code. This approach allows reducing the complexity of technical implementation of the test circuit by decreasing the number of checked functions in the compression circuit. The number of testing organization variants of combinational devices is rather large, because it is possible to choose the compressed functions and the techniques for transforming each data vector to the code word of the "1-out-of-4" code. The paper shows that the new approach to organizing self-checking combinational devices allows improving the characteristics of distortion detection in data vectors in comparison with the traditional approach to organizing testing of devices by parity, even without special circuit analysis methods.
We study and propose schemes that map messages onto constant-weight codewords using variable-length prefixes. We provide polynomial-time computable formulas that estimate the average number of redundant bits incurred ...
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We study and propose schemes that map messages onto constant-weight codewords using variable-length prefixes. We provide polynomial-time computable formulas that estimate the average number of redundant bits incurred by our schemes. In addition to the exact formulas, we also perform an asymptotic analysis and demonstrate that our scheme uses 1/2 log(2) n + O(1) redundant bits to encode messages into length- n words with weight $(n/2)+ mu for constant mu . We also propose schemes that map messages into balanced codebooks with error-correcting capabilities. For such schemes, we provide methods to enumerate the average number of redundant bits.
A cyclic (n, d, w)(q) code is a cyclic q-ary code of length n, constantweight w and Hamming distance at least d. The function C A(q) (n, d, w) denotes the largest possible size of a cyclic (n, d, w) q code. A new con...
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A cyclic (n, d, w)(q) code is a cyclic q-ary code of length n, constantweight w and Hamming distance at least d. The function C A(q) (n, d, w) denotes the largest possible size of a cyclic (n, d, w) q code. A new construction, which is based on two (n, 2, 1) cyclic difference packings with given properties, is proposed for optimal (n, 3, 3)(4)codes. As a result, the exact value of C A(4)(n, 3, 3) is determined for n 18 (mod 24), and the spectrum of C A(4)(n, 3, 3) is then completely determined.
This paper studies properties of binary runlength-limited sequences with additional constraints on their Hamming weight and/or their number of runs of identical symbols. An algebraic and a probabilistic (entropic) cha...
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This paper studies properties of binary runlength-limited sequences with additional constraints on their Hamming weight and/or their number of runs of identical symbols. An algebraic and a probabilistic (entropic) characterization of the exponential growth rate of the number of such sequences, i.e., their information capacity, are obtained by using the methods of multivariate analytic combinatorics, and properties of the capacity as a function of its parameters are stated. The second-order term in the asymptotic expansion of the rate of these sequences is also given, and the typical values of the relevant quantities are derived. Several applications of the results are illustrated, including bounds on codes for weight-preserving and run-preserving channels (e.g., the run-preserving insertion-deletion channel), a sphere-packing bound for channels with sparse error patterns, and the asymptotics of constant-weight sub-block constrained sequences. In addition, the asymptotics of a closely related notion-q-ary sequences with fixed Manhattan weight-is briefly discussed, and an application in coding for molecular timing channels is illustrated.
The study of constant-weight codes in l(1)-metric was motivated by the duplication-correcting problem for data storage in live DNA. It is interesting to determine the maximum size of a code given the length n, weight ...
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The study of constant-weight codes in l(1)-metric was motivated by the duplication-correcting problem for data storage in live DNA. It is interesting to determine the maximum size of a code given the length n, weight w, minimum distance d and the alphabet size q. In this paper, based on graph decompositions, we determine the maximum size of ternary codes with constantweight w and distance 2w - 2 for all sufficiently large length n. Previously, this was known only for a very sparse family n of density 4/w(w - 1).
We prove that the maximum number of words in a code that corrects a fraction of 1/4+ epsilon of asymmetric errors in a Z-channel is Theta(epsilon(-3/2)) as epsilon -> 0.
We prove that the maximum number of words in a code that corrects a fraction of 1/4+ epsilon of asymmetric errors in a Z-channel is Theta(epsilon(-3/2)) as epsilon -> 0.
Motivated by the duplication-correcting problem for data storage in live DNA, we study the construction of constant-weight codes in l(1)-metric. By using packings and group divisible designs in combinatorial design th...
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Motivated by the duplication-correcting problem for data storage in live DNA, we study the construction of constant-weight codes in l(1)-metric. By using packings and group divisible designs in combinatorial design theory, we give constructions of optimal codes over non-negative integers and optimal ternary codes with l(1)-weight w <= 4 for all possible distances. In general, we derive the size of the largest ternary code with constantweight w and distance 2w - 2 for sufficiently large length n satisfying n equivalent to 1, w, -w + 2, -2w + 3 (mod w(w - 1)).
For nonnegative integers n, d, and w, let A(n, d, w) be the maximum size of a code C subset of F-n 2 with a constantweight w and minimum distance at least d(2). We consider two semidefinite programs based on quadrupl...
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For nonnegative integers n, d, and w, let A(n, d, w) be the maximum size of a code C subset of F-n 2 with a constantweight w and minimum distance at least d(2). We consider two semidefinite programs based on quadruples of code words that yield several new upper bounds on A(n, d, w). The new upper bounds imply that A(22, 8, 10) = 616 and A(22, 8, 11) = 672. Lower bounds on A(22, 8, 10) and A(22, 8, 11) are obtained from the (n, d) = (22, 7) shortened Golay code of size 2048. It can be concluded that the shortened Golay code is a union of constant-weight w codes of sizes A(22, 8, w).
A cyclic code is a cyclic q-ary code of length n, constant-weight w and minimum distance d. A cyclic code with the largest possible number of codewords is said to be optimal. Optimal nonbinary cyclic codes were first ...
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A cyclic code is a cyclic q-ary code of length n, constant-weight w and minimum distance d. A cyclic code with the largest possible number of codewords is said to be optimal. Optimal nonbinary cyclic codes were first studied in our recent paper (Lan et al. in IEEE Trans Inf Theory 62(11):6328-6341, 2016). In this paper, we continue to discuss the constructions of optimal cyclic codes. We establish the connection between cyclic codes and mutually orbit-disjoint cyclic (n, 3, 1) difference packings (briefly (n, 3, 1)-CDPs). For the case of , we construct three mutually orbit-disjoint (n, 3, 1)-CDPs by constructing a pair of strongly orbit-disjoint (n, 3, 1)-CDPs, which are obtained from Skolem-type sequences. As a consequence, we completely determine the number of codewords of an optimal cyclic code.
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