Experimental investigation of UAV-assisted FSO-CDMA system over turbulent channel with vibration effects

Abstract

In this paper, we novelly proposed a hybrid network solution of optical code division multiple access (OCDMA) and unmanned aerial vehicle (UAV) based free space optical (FSO) communication technologies, namely UAV-assisted FSO-OCDMA communication system, which can be used in secure communication scenarios such as military reconnaissance. This paper describes the architecture of the proposed UAV-assisted FSO-OCDMA communication network as well as the experimental scheme in detail. In this paper, we investigate the performance impact of different atmospheric turbulence intensities on the proposed system based on a 10 Gb/s FSO-OCDMA communication experiment platform. It is worth noting that this is the first time to experimentally study the security performance of OCDMA encoded FSO system considering UAV's vibration reception through a mechanical vibration platform. Furthermore, eye diagrams and average bit error rate (BER) metrics are used to represent the impact of atmospheric turbulence and vibration effects on system transmission performance in single-user and dual-user scenarios considering the presence of an eavesdropper. The experimental results show that the system can meet the reliability of communication in single-user and dual-user scenarios at a data rate of 10 Gb/s. When the transmission power is −8.5 dBm and the vibration amplitude is 0.20 mm under weak turbulence for a dual-user system, the BER of the legitimator and eavesdropper is 8.78 × 10⁻⁴ and 0.0276, respectively. The eavesdropper was unable to successfully recover the signal, indicating that the considered system can achieve security communication. Therefore, the UAV-assisted FSO-OCDMA system can be used as a communication service to provide flexible deployment, high rate, and high security.