Abstract

For the future optical broadband networks, Free Space Optical (FSO) communication system becomes a promising\nsolution. This paper is focused to analyse the performance of Orthogonal Frequency Division Multiplexing (OFDM) FSO\ncommunication system using the Optical Double Sideband (ODSB), Optical Single Sideband (OSSB) and Optical Vestigial\nSideband (OVSB) modulation techniques by employing the Spatial Diversity that uses multiple Transmitter/Receiver\n(TX/RX) system. A 10 Gbps data is transmitted by using 4-QAM technique through the free air space under the clear, haze\nand fog weather conditions. Results shows that by employing the spatial diversity using 8 TX/RX, OFDM-FSO system\nprovides communication up to 292 km with acceptable Signal to Noise Ratio (SNR) under clear weather condition whereas\nunder the fog weather condition, this system prolongs to 3.24 km and also concluded that for long haul free space optical\ncommunication, OVSB-OFDM FSO system performs better than OFDM-ODSB and OFDM-OSSB FSO system.