Influence of short range free space optical atmospheric attenuation in modulated radio signal

Optical wireless communication systems supply high data rate for bandwidth communication applications. Free space optical can be a new solution for these communication system and next generation networks. However, weather effects and atmospheric attenuation decrease the optical link visibility and wavelength transmissivity. This paper shows that 2.5Gbps, 2bits/symbol quadrature amplitude modulation radio signal by using orthogonal frequency division multiplexing is transmitted over free space optical channels. The results indicates that bit error rate of this radio over fiber technology would be less than 10 -15 and the measure of power penalty is smaller than 0.7dBm for link range of 0.2km at wavelength of 1550nm.