52,538 research outputs found

    Finite Blocklength Rates over a Fading Channel with CSIT and CSIR

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    In this work, we obtain lower and upper bounds on the maximal transmission rate at a given codeword length nn, average probability of error ϵ\epsilon and power constraint Pˉ\bar{P}, over a finite valued, block fading additive white Gaussian noise (AWGN) channel with channel state information (CSI) at the transmitter and the receiver. These bounds characterize deviation of the finite blocklength coding rates from the channel capacity which is in turn achieved by the water filling power allocation across time. The bounds obtained also characterize the rate enhancement possible due to the CSI at the transmitter in the finite blocklength regime. The results are further elucidated via numerical examples.Comment: 10 pages, 2 figures, results for finite valued fading states, typos corrected, proofs elaborated, lower bound under short term power constraint improve

    Magnetic moments of spin {1/2}^+ and spin {3/2}^+ charmed baryons

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    The magnetic moments of spin 1/2+{1/2}{^+} and spin 3/2+{3/2}{^+} charmed baryons have been calculated in chiral constituent quark model (χ\chiCQM). The effects of configuration mixing and quark masses have also been investigated. The results are not only in good agreement with existing experimental data but also show improvement over other phenomenological models.Comment: 5 pages, 2 tables. Presented at the XIII International Conference on Hadron Spectroscopy, Florida State University, Florida, USA, November 29-December 4, 200

    Interactions of satellite-speed helium atoms with satellite surfaces. 3: Drag coefficients from spatial and energy distributions of reflected helium atoms

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    Spatial and energy distributions of helium atoms scattered from an anodized 1235-0 aluminum surface as well as the tangential and normal momentum accommodation coefficients calculated from these distributions are reported. A procedure for calculating drag coefficients from measured values of spatial and energy distributions is given. The drag coefficient calculated for a 6061 T-6 aluminum sphere is included

    Electric and Magnetic fields due to Dirac particles in FRW spacetime

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    Some solutions of the Maxwell equations with Dirac particles for the source in FRW spacetime are discussed. The Green's function of the equation for the radial component of the Maxwell fields, F_{r\eta} and F_{\theta\phi} is solved. Green's function is found to reduce to that of Minkowskian spacetime in the appropriate limit. Also, the Lienard-Wiechert type solution is derived. Also, the solutions with the Dirac particle current is also presented. It is found that the F_{r\eta} is composed of even angular momentum states while the odd states constitue F_{\theta\phi} .Comment: 8 pages including 2 figure
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