We consider the possibility that the Galactic neutral hydrogen stream Complex A and the stellar Orphan stream are related, and use this hypothesis to determine possible distances to Complex A and the Orphan stream, and line-of-sight velocities for the latter. The method presented uses our current knowledge of the projected positions of the streams, as well as lineof-sight velocities for Complex...

In this paper, empirical channel models and parameters are derived from the wideband measured data at 5.3 GHz in outdoor mobile communications. The path loss exponents and intercepts are obtained by using the least square method. The mean excess delay and mean root-mean-square (rms) delay spread are within 29–102 ns and 22–88 ns, respectively. The correlation distances and bandwidths are within...

Classification of line-of-sight (LOS) or non-LOS (NLOS) propagation is critical for most pulsed ultrawideband localisation systems. In this letter, first, the authors propose a two-dimensional (2D) LOS/NLOS classification scheme that uses skewness of the channel impulse/pulse response, which has not been used by existing work. The log-likelihood ratio of the 2D LOS/NLOS classification is used t...

Underwater optical wireless communication (UOWC) systems have been widely studied to achieve high-speed communications. To investigate and design UOWC systems, a mathematical model characterize the accurate performance of is important. However, previous models limitations, which mainly focused on line-of-sight (LOS) link, only considered vertical incident background light or filters with consta...

We here present a general and tractable model for line-of-sight (LOS) scenarios, which is based on the product of two independent and non-identically distributed κ-μ shadowed random variables. Simple closed-form expressions for the probability density function, cumulative distribution function and moment-generating function are derived, which are as tractable as the corresponding expressions de...

In this paper, the product of two α-k-μ random variables is analyzed. The closed form expressions for average level crossing rate (LCR) of product of two α-k-μ random variables are determined. These expressions are used for calculation of average level crossing rate of wireless communication systems operating over α-k-μ multipath fading channels. The α-k-μ distribution can be used to describe s...

Recently, there is a lot of interest in the field of under water optical wireless communication for short range because of its high bandwidth. But in most of the previous works line of sight propagation or single scattering of photons only considered. In practical case this is not applicable because of beam blockage in underwater and multiple scattering also occurred during the photons propagat...