Results 211 to 220 of about 663 (237)

The Deficiency of Costas Arrays

IEEE Transactions on Information Theory, 2014
A Costas array is a permutation array in which the vectors joining pairs of 1s are all distinct. The toroidal vectors of a permutation array are the vectors occurring when the array is written on a torus, and the deficiency of a permutation array of order n is the number of toroidal vectors, out of the (n 1) 2 possible, which are missing from the ...
Jonathan Jedwab, Jane Wodlinger
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Sparse antenna arrays based on Costas arrays

Asia-Pacific Conference on Fundamental Problems of Opto- and Microelectronics 2017, 2019
Igor Anikin, Valery Sorokovikov
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Difference-based structural properties of costas arrays

Designs, Codes and Cryptography, 2022
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Bill Correll Jr., Christopher N. Swanson
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Two experimental pearls in Costas arrays

2008 42nd Annual Conference on Information Sciences and Systems, 2008
The results of 2 experiments in Costas arrays are presented, for which theoretical explanation is still not available: the number of dots on the main diagonal of exponential Welch arrays, and the parity populations of Golomb arrays generated in fields of characteristic 2.
Konstantinos Drakakis, Rod Gow
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On costas arrays

Journal of Electronics (China), 1992
Costas array is a class of radar signal array with perfect correlation property. An open problem about the limiting performance of the costas array (i.e. the Golomb-Taylor’s fifth conjecture) is solved in this paper.
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The Enumeration of Costas Arrays of Size 26

2006 40th Annual Conference on Information Sciences and Systems, 2006
We present results of a grid computer search which enumerated the number of 26-by-26 Costas arrays. Of the 26! possible permutation matrices, only 56 of them satisfy the Costas condition that the N choose 2 line segments connecting pairs of ones are all distinct.
Scott Rickard, Edward Connell, Frank Duignan, Bruce Ladendorf, Aidan Wade   +4 more
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On Costas arrays with various types of symmetry

2009 16th International Conference on Digital Signal Processing, 2009
Using the database of Costas arrays of orders 27 and below, a table is generated showing the number of arrays which exhibit some kind of symmetry. The number of diagonal, anti-reflective and consecutive arrays are given, correcting previously published results in a small number of cases.
Ken Taylor, Scott Rickard, Konstantinos Drakakis   +2 more
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The Status of Costas Array Construction

2006 40th Annual Conference on Information Sciences and Systems, 2006
To date, two approaches have been followed to identify Costas arrays. One has been exhaustive search, by computer, to find all n × n Costas arrays, which has currently been completed for n ? 26. [1] [2] [3]. The other has been the discovery of specific constructions which provide examples of Costas arrays for many different values of n [4] [5] [6]. All
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A remark on the definition of Costas arrays

Proceedings of the IEEE, 1987
A weaker definition of Costas arrays is shown to be equivalent to the standard one. A Costas array is a diagram whose corresponding frequency-hopping pattern has good range-doppler ambiguity properties. Our result implies that even when we demand ostensibly less restrictive ambiguities in the doppler direction, the resulting waveform becomes a Costas ...
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The enumeration of Costas arrays of order 28

2010 IEEE Information Theory Workshop, 2010
We present the results of the enumeration of Costas arrays of order 28: all arrays found are accounted for by the Golomb and Welch construction methods, making 28 the first order (larger than 5) for which no sporadic Costas arrays exist. The enumeration was performed on several computer clusters and required the equivalent of 70 years of single CPU ...
Konstantinos Drakakis, Francesco Iorio, Scott Rickard   +2 more
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