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131.
Let Dn be the set of all signed permutations on [n] = {1,... ,n} with even signs, and let :Dn(T) be the set of all signed permutations in Dn which avoids a set T of signed patterns. In this paper, we find all the cardinalities of the sets Dn(T) where T B2. Some of the cardinalities encountered involve inverse binomial coefficients, binomial coefficients, Catalan numbers, and Fibonacci numbers. 相似文献
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In this work, we use a new approach that relies on the theory of matrix iterative analysis to study the convergence behavior
of the linear group-wise successive interference cancellation (GSIC) detector. Particularly, we show that the linear GSIC
detector is in fact a realization of a modified block successive over-relaxation (BSOR) iterative method where the relaxation
factor is a matrix instead of scalar. Consequently, to study the convergence behavior of the GSIC detector, we propose two
new corollaries that extend the famous work of Kahan (Varga, Matrix iterative analysis, 2000) to the case where the relaxation
factor is a matrix instead of a scalar. Using the two new corollaries we develop two new conditions of convergence for the
linear GSIC detector. Simulation results are in excellent agreement with theory.
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A. ZerguineEmail: |
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The generation of efficient Gray codes and combinatorial algorithms that list all the members of a combinatorial object has
received a lot of attention in the last few years. Knuth gave a code for the set of all partitions of [n] = {1,2,...,n}. Ruskey presented a modified version of Knuth’s algorithm with distance 2. Ehrlich introduced a looplees algorithm for the
set of the partitions of [n]; Ruskey and Savage generalized Ehrlich’s results and introduced two Gray codes for the set of partitions of [n]. In this paper, we give another combinatorial Gray code for the set of the partitions of [n] which differs from the aforementioned Gray codes. Also, we construct a different loopless algorithm for generating the set
of all partitions of [n] which gives a constant time between successive partitions in the construction process.
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136.
Smain Balaska Toufik Sahabi 《理论物理通讯》2009,51(1):115-122
We consider the minimal conformaJ model describing the tricritical Ising model on the disk and on the upper half plane. Using the coulomb-gas formalism we determine its consistents boundary states as well as its one-point and two-point correlation functions. 相似文献
137.
Abdelouahab Bentrcia Azzedine Zerguine Moussa Benyoucef 《Wireless Communications and Mobile Computing》2009,9(9):1173-1180
In this work, we introduce a new chip‐level linear modified‐SIC multi‐user structure that is asymptotically equivalent to successive over‐relaxation (SOR) iteration, which is known to outperform the conventional Gauss–Seidel iteration by an order of magnitude in terms of convergence speed. The main advantage of this scheme is that it uses directly the spreading codes and not the cross‐correlation coefficients and thus reduces significantly the overall computational complexity. This is critical for the design of low‐complexity multiuser detectors for long‐code CDMA systems such as IS95 and UMTS. We use a matrix algebraic approach to show the equivalence of the proposed scheme to linear matrix filtering. This allows obtaining an analytical expression for both the bit‐error rate (BER) and the asymptotic multiuser efficiency (AME). Moreover, we study the convergence behavior of the proposed scheme and prove that it converges if the relaxation factor is within the interval ]0, 2[. Simulation results are in excellent agreement with theory. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
138.
A. Bentrcia A. Zerguine A. U. Sheikh 《Wireless Communications and Mobile Computing》2007,7(5):595-604
In this paper, we consider a linear group polynomial expansion successive interference cancellation (GPE‐SIC) detector in a synchronous CDMA system. It is a hybrid detector, which combines parallel and successive cancellation techniques in order to extract the advantages of both schemes. We use the fact that even if the cross‐correlation matrix of the system is not diagonal dominant, the sub‐matrices corresponding to different groups can be forced to be diagonal dominant by suitable grouping of users to approximate the decorrelator/MMSE detector by a low‐complexity polynomial expansion detector. The latter is computationally very efficient if the cross‐correlation matrix of users within the same group is diagonal dominant. Simulation results showed that the (GPE‐SIC) detector has the same performance as the linear group decorrelator successive interference cancellation (GDEC‐SIC) detector but with low‐computational complexity. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
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Toufik Ahmed Emmanuel Dubois Jean‐Baptiste Dupé Ramon Ferrús Patrick Gélard Nicolas Kuhn 《International Journal of Satellite Communications and Networking》2018,36(1):108-133
This paper provides an assessment study on the virtualization of a Digital Video Broadcasting ‐ Satellite ‐ Second Generation (DVB‐S2)/ Digital Video Broadcasting ‐ Return Channel Satellite ‐ Second Generation (DVB‐RCS2) satellite ground infrastructure and proposes a framework, named Satellite Cloud Radio Access Network (SatCloudRAN), that aims to ease the integration of satellite components in forthcoming 5G systems. Special attention is given to the design of SatCloudRAN by considering the split and placement of virtualized and nonvirtualized functions while taking into account the characteristics of the transport links connecting both type of functions. We assess how virtualization and softwarization technologies, namely, network function virtualization and software‐defined networking, can deliver part of the satellite gateway functionalities as virtual network functions and achieve a flexible and programmable control and management of satellite infrastructure. Under the network function virtualization paradigm, building virtual network function blocks that compose a satellite gateway have been identified, and their interaction exhibited. This paper also gives insights on how the SatCloudRAN approach can allow operators to provide software‐defined networking‐based (1) bandwidth on demand, (2) dynamic Quality of Service, and (3) satellite gateway diversity. Copyright © 2017 John Wiley & Sons, Ltd. 相似文献