Channel Capacity of MIMO FSO System under Strong Turbulent Condition

Free Space Optics (FSO) or optical wireless communication is a promising solution for the need to very high data rate point-to-point communication. In FSO communication links, atmospheric turbulence causes fluctuations in both the intensity and the phase of the received light signal, impairing link performance. This intensity fluctuation, also known as scintillation is one of the most important factors that degrade the performance of an FSO communication link even under the clear sky condition. This paper investigates the use of multiple lasers and multiple apertures to mitigate the effects of scintillation. Also an analytical approach is presented to evaluate the channel capacity of a free space optical link using Q-ary optical PPM under strong atmospheric turbulent condition. In this view, we propose design rules for optimal channel capacity of the system. Index Term— Free space optics (FSO), pulse position modulation (PPM), probability of density function (PDF), channel capacity,