Design and performance analysis of 5G PON employing filtered OFDM

Abstract

This paper presents a physical-layer performance analysis of a 160 Gbps Passive Optical Network (PON) for 5G fronthaul applications, employing Filtered Orthogonal Frequency Division Multiplexing (F-OFDM). To mitigate the high Out-of-Band (OOB) emission issues inherent in conventional OFDM, the proposed architecture integrates the 15th order Butterworth Band Pass Filters (BBPF) at both the Optical Line Terminal (OLT) and Optical Network Unit (ONU). This leads to a BBPF system-level which is used in Radio Frequency (RF), cognitive radio platforms, satellite communication systems, Wi-Fi and cellular base stations, Radar signal processing and digital communication systems. The system is modelled and simulated using OptiSystem to evaluate bidirectional transmission over a 50 km Standard Single Mode Fiber (SSMF) link for four concurrent users. Analytical models are developed to quantify the impact of laser source power (varied from −10 dBm to + 15 dBm) on the optical spectrum, Optical Signal-to-Noise Ratio (OSNR), and Bit Error Rate (BER). The results obtained demonstrate that the proposed filtering stage achieves a sidelobe suppression of approximately 30–40 dB, effectively maintaining the signal within a strict 8 GHz channel spacing. At the optimum laser source power of 5 dBm, the system achieves a minimum BER of 1.49 × 10 -5 for downstream transmission and 2.98 × 10 -5 for upstream, both significantly below the pre- Forward Error correction (FEC) threshold. Furthermore, the architecture exhibits a spectral efficiency of 5 bits/s/Hz, validating its scalability and robustness against fiber non-linearities in next-generation high-capacity optical access networks.