Performance analysis of high speed backward compatible TWDM-PON with hybrid WDM–OCDMA PON using different OCDMA codes

In this paper, a backward compatible bidirectional 160/40 Gbps time and wavelength division multiplexing-passive optical network with hybrid wavelength division multiplexing optical code division multiple access PON (WDM–OCDMA PON) has been proposed. Six OCDMA codes have been used to enhance the security and users’ ability to access shared bandwidth of an optical network. In this “pay-as-you-grow” supported system, the fiber impairment effects have been effectively reduced. The performance of the proposed system has been analyzed for variable input power (4–19 dBm) and transmission distance (10–70 km) supporting 120 active users under the influence of fiber nonlinearities, attenuation, dispersion and noise. Based on the numerical calculations, the proposed system using modified quadratic congruence (MQC) code is shown to provide better performance compared to multi diagonal, hadamard, zero cross-correlation (ZCC), shift ZCC and flexible cross-correlation codes. To validate the numerical analysis, the simulation of the proposed system at 160/40 Gbps data rate for 70 km downstream and greater than 70 km upstream fiber link transmission at 10⁻⁹ BER limit for 68 active users have been successfully demonstrated. Also, it has been shown that MQC code provides optimum results at 10 dBm input power over 55 km distance and supports more than 120 active users with high gain of − 1.97 dB and low noise figure of 2 dB. Further, the comparative performance of the proposed system with the previous latest works in literature reveals a superior performance of the system.