Hybrid Chaotic Scheme for Secure OFDM-PON Transmission

Different chaotic security schemes have been applied in the literature to secure transmission over orthogonal frequencies-division multiplexing (OFDM)-passive optical networks (PONs). All these schemes have been based on threedimensional (3D) or four-dimensional (4D) chaos systems and have been applied to direct-detection (DD) OFDM-PONs. This paper proposes the use of 7D hybrid chaotic scheme to provide physical-layer security in both DD and coherent OFDM-PONs. The hybrid scheme uses a combination of 3D chaotic mapping scheme and 4D chaotic discrete Hartley transform precoding. The proposed chaotic security scheme is applied successfully for both DD-and coherent OFDM-PONs, and the results show that the security is very sensitive to initial conditions of both subchaotic systems.