612 research outputs found
Maximum likelihood detection for OFDM signals with strong nonlinear distortion effects
Dissertação para obtenção do Grau de Mestre em
Engenharia Electrotécnica e de Computadore
A Hardware Oriented Method to Generate and Evaluate Nonlinear Interleaved Sequences with Desired properties
It is well known that the combinatorial structure, algebraic structure and D-transform based method render the nonlinear sequences with good autocorrelation function (ACF) and great linear complexity (LC). However, “all sequences” are not equal even if they are “born” by the same method! In this paper the big inequalities regarding LC of these sequences are shown based on a hardware oriented method (D-transform). In order to get the right sequences some more extensive simulations and trade off are needed. That is why this paper is represented here with above Title. Keywords: cryptography, mobile communications, security, watermarking, D-transfor
Non-Gaussian statistics in space plasma turbulence, fractal properties and pitfalls
Magnetic field fluctuations in the vicinity of the Earth's bow shock have
been investigated with the aim to characterize the intermittent behaviour of
strong plasma turbulence. The observed small-scale intermittency may be the
signature of a multifractal process but a deeper inspection reveals caveats in
such an interpretation. Several effects, including the anisotropy of the
wavefield, the violation of the Taylor hypothesis and the occasional occurrence
of coherent wave packets, strongly affect the higher order statistical
properties. After correcting these effects, a more Gaussian and scale-invariant
wavefield is recovered.Comment: 13 pages (including 13 postscript figures), to appear in Nonlinear
Processes in Geophysic
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