Disaster management using free space optical communication system

摘要

A novel method for disaster management using free space optical link is proposed in this paper. Free space optics recently gained great attention since it has advantages over RF communication such as high bandwidth, license free spectrum and highly secured transmission. Besides all these, FSO faces challenges during transmission due to atmospheric turbulence-induced fading. Diversity techniques are used in this paper to mitigate the fading effects. The capacity of multiple input multiple output (MIMO) free space optical (FSO) networks is increased using polarization division multiplexing (PDM). This paper proposed a novel method of MISO and MIMO-OFDM which uses both odd and even subcarriers to improve the transmission capacity. The separated OFDM subcarriers are combined using PDM, which supports two independent data channels on a single wavelength with orthogonal polarization states. The system performance is evaluated under various atmospheric turbulence conditions. This paper introduces a novel application of MIMO-FSO system during disaster scenario. The atmosphere is considered to be turbulent in nature, and Malaga model is used to characterize the channel. The closed-form expressions for MIMO-FSO are derived, and the graphs for the performance under different turbulent conditions are plotted.