Transmission Analysis of CDMA-Based Wireless Services over Turbulent Radio-on-FSO Links Using Aperture Averaging

In this paper, we study the performance of a Radio over Free-Space Optical (RoFSO) system for transmitting Code Division Multiple Access (CDMA) signals using aperture averaging (AA) technique, in terms of Carrier-to-Noise-plus- Interference Ratio (CNIR) and outage probability. We propose a modified analytical model for AA, taking into consideration the intermodulation distortion term due to the laser diode nonlinearity and the multiple interference access. By investigating the impact of AA on our model across weak-to-strong turbulence regimes, we show that there is a design tradeoff between the receiver lens aperture and the number of users to achieve a required CNIR ensuring a substantial scintillation fade reduction.