Due to ever-increasing demand for capacity and quality in wireless communication links, lead to inspire researchers to innovate new design methodologies and concepts over wireless systems and networks with the ultimate aim of achieving a next-generation network. These researches must ensures data rates similar to those offered by optical fiber systems but at the fraction of its deployment cost. Among the emerging technologies is the new innovative radio on freespace optics system, referred to as Radio over Free Space Optics (RoFSO), which is the main interest of this paper. RoFSO systems have been recognized as a promising wireless interconnecting technology. Such system combines the radio over fiber (RoF) technology comprising heterogeneous wireless services and Fiber Space Optics (FSO) link. In this paper, an analytical time-domain model is presented to analyze the radio over free space optical (RoFSO) systems considering scintillation effect with the log-normal distribution. This analytical model uses a dual-drive MachZehnder modulator (DD-MZM) and photodetector (PD) for optical single sideband (OSSB) signals.

The optical and wireless communication systems convergence will activate the potential capacity of photonic technology for providing the expected growth in interactive video, voice communication and data traffic services that are cost effective and a green communication service. The last decade growth of the broadband internet projects the number of active users will grow to over 2 billion globally by the end of 2014. Enabling the abandoned capacity of photonic signal processing is the promising solution for seamless transportation of the future consumer traffic demand. One emerging technology applicable in high capacity, broadband millimeter-wave access systems is Radio over Fiber also called Fiber To The Air (FTTA). In this paper, Optical SSB signal is specifically selected as it has tolerance for power degradation due to dispersion effects over a length of fiber and CNR (carrier to noise ratio) performance is evaluated in terms of phase noise from RF oscillator Linewidth and laser linewidth. Signal degradation is studied for various lengths of fibers in the presence of fiber chromatic dispersion.