Investigating the Performance of low-cost millimeter wave for long-distance Front haul RoF system based on Pre-distortion & FBG techniques

Abstract

Abstract In this work, the effects of both Pre-distortion devices and fiber brag grating (FBG) techniques on the optical (mm-wave) in Front haul RoF have been investigated. The scope of this work is to design a simple and low-cost but efficient RoF mmm-wave-based system by utilizing a single Dual Drive Mach- Zehnder modulator (DDMZM) to feed up-converted baseband signals of different transmission rates 1,2.5, 5, 10 Gbps at input frequencies of 15, 30, 60, 65 GHz respectively. The Predistortion (PD) technique has been proven to enhance the linearity of transmitter amplifiers, which results in boosting the power efficiency of the proposed model and hence combats the non-linearity, which is one of the main problems in the RoF link. Two pulse generators have been tested in this work: Return-to-Zero (RZ) and Non-Return-to- Zero (NRZ). A single-mode fiber (SMF) is equipped with FBG to compensate for link dispersion along with an erbium-doped fiber amplifier (EDFA) and at a far terminal, an optical Gaussian filter (GOF) is employed to mitigate attenuation and band limit the optical received signal, respectively. The simulation results revealed that a Q-factor of around 8.67, and BER of 2.05E-18 can be achieved when combining both Pre-distortion and RZ format along with Pre-FBG technologies with a fiber link of 140km at 5Gbps bitrate utilizing 15 GHz local oscillator 60 GHz mm-wave. The findings showed that a 130 GHz mm-wave is generated with Q-factor of 7.4, and BER of 5.08E-14 with fiber length of 140 km and a data rate of 1Gbps.