Performance analysis of a free-space optical communication system through atmospheric turbulence channels

Abstract

Free space optical (FSO) communication technology is a promising candidate for next generation broadband networking, due to its large bandwidth potential, unlicensed spectrum, excellent security and quick and inexpensive setup and used to solve the "last mile" problem to bridge the gap between the end user and the fiber-optic infrastructure already in place [1, 2]. Its unique properties make it also appealing for a number of other applications, including metropolitan area network extensions, local area network connectivity, fiber backup, back-haul for wireless cellular networks, redundant link and disaster recovery. In FSO communications, optical transceivers communicate directly through the air to form point-to-point line-of-sight (LOS) links. One major impairment over FSO links is the atmospheric turbulence, which occurs as a result of the variations in the refractive index due to inhomogeneities in temperature and pressure fluctuations [3, 4]. Atmospheric turbulence has been studied extensively and various theoretical models have been proposed to describe turbulence- induced image degradation and intensity fluctuations (i.e., signal fading) [5,6]. Performance of single receiver system for log-normal model has already been studied [7]. But it is very important to consider other turbulence model as well as other modulation scheme.