Performance enhancement of 64 Gb/s OFDM system at 1550 nm over multimode fiber using Volterra equalization

Based on a developed analytical model, we demonstrate the feasibility of intensity-modulation direct-detection (IM/DD) optical orthogonal frequency division multiplexing (OOFDM) system over 1 km of multimode fiber (MMF) at data rates up to 64 Gb/s, at 1550 nm. The effect of data rates, number of subcarriers and fiber length are investigated for different number of excited mode groups that can be generated using the offset launch technique. Indeed, we show that when we increase the efficiency of the Volterra equalizer, by raising its input taps from 7 to 9, we can reduce the system impairments of 5.45 dB in terms of Q factor at 800 m. Furthermore, we prove that by exciting more mode groups the MMF bandwidth is reduced potentially. Finally, thanks to the efficiency of Volterra equalizer, we achieve a bit error rate (BER) below the forward error correction (FEC) limit, even in the case of the full excitation technique.