Performance Evaluation of FSO-OCDMA Based on Security Perspective

With the high explosion in data traffic in today's networks, the importance of secure and high-capacity optical wireless communication has become more pressing than ever before. Free Space Optics (FSO) in combination with Optical Code Division Multiple Access (OCDMA) has great potential to meet these demands. However, most of the current research has considered system performance and physical layer security independently and left a major gap in our knowledge on how they interact, particularly under practical conditions in the real atmosphere. This study takes up this challenge by investigating the combined operation of performance and security in FSO-OCDMA systems that are necessary for protection against eavesdropping, jamming and unauthorized access. We investigate a few FSO-OCDMA techniques such as PD-NOMA, SAC-OCDMA with various coding schemes, hybrid fiber-wireless (FiWi) systems and OAM-based multiplexing schemes in various turbulence conditions. Through simulation testing, we cover some of the most important metrics including Bit Error Rate (BER), signal robustness and security threats. Our results demonstrate that well-optimized modulation and coding schemes, and specifically that SAC-OCDMA combined with sophisticated zero cross-correlation coding schemes, dramatically enhance the system security while at the same time enhancing the communication reliability. These results offer practical advice for construction of the next generation of secure, high-performance optical wireless networks.