Electronics

Researchers at Pennsylvania State University target communications research

  2010 JAN 6 - (VerticalNews.com) -- "Free Space Optical (FSO) communications is a practical solution for creating a three dimensional global broadband communications grid, offering bandwidths far beyond possible in Radio Frequency (RF) range. However, attributes of atmospheric turbulence (scintillation) and obscurants such as clouds impose perennial limitations on availability and reliability of optical links," scientists writing in the IEEE Journal on Selected Areas in Communications report.

  "To design and evaluate optimum transmission techniques that operate under realistic atmospheric conditions, a good understanding of the channel behavior is necessary. In most prior works, Monte-Carlo Ray Tracing (MCRT) algorithm has been used to analyze the channel behavior. This task is quite numerically intensive. The focus of this paper is on investigating the possibility of simplifying this task by a direct extraction of state transition matrices associated with standard Markov modeling from the MCRT computer simulations programs. We show that by tracing a photon's trajectory in space via a Markov chain model, the angular distribution can be calculated by simple matrix multiplications. We also demonstrate that the new approach produces results that are close to those obtained by MCRT and other known methods," wrote Z. Hajjarian and colleagues, Pennsylvania State University.

  The researchers concluded: "Furthermore, considering the fact that angular, spatial, and temporal distributions of energy are inter-related, mixing time of Monte-Carlo Markov Chain (MCMC) for different types of aerosols is calculated based on eigen-analysis of the state transition matrix and possibility of communications in scattering media is investigated."

  Hajjarian and colleagues published their study in IEEE Journal on Selected Areas in Communications (Analysis of Wireless Optical Communications Feasibility in Presence of Clouds Using Markov Chains. IEEE Journal on Selected Areas in Communications, 2009;27(9):1526-1534).

  Additional information can be obtained by contacting Z. Hajjarian, Pennsylvania State University, Dept. of Electrical Engineering, University Park, PA 16802, USA.

  The publisher of the IEEE Journal on Selected Areas in Communications can be contacted at: IEEE-Institute Electrical Electronics Engineers Inc., 445 Hoes Lane, Piscataway, NJ 08855, USA.

  Keywords: City:University Park, State:PA, Country:United States, Bandwidth, Broadband, Communications Research, Computers, Electronics, Photons, Radio Frequency

  This article was prepared by VerticalNews Electronics editors from staff and other reports. Copyright 2010, VerticalNews Electronics via VerticalNews.com.