Radio-over-Fiber Dual-Parallel Mach–Zehnder modulator system for photonic generation of Millimeter-Wave signals through two stages

In this work, we presented a radio-over-fiber (ROF) access network through two modulation stages for the generation of multiple millimeter wave (mm-wave) signals with frequencies of 20, 40, 60 and 80 GHz for the transmission rate of 10 Gbps as a function of the variation of link distance and signal power. The specific purpose of the paper was to design and to investigate a RoF system based on the variation of mm-wave frequencies in order to implement a simple and effective system. In stage 1, there are two modulators in parallel (MZMa and MZMb) called dual-parallel Mach–Zehnder modulator (DP-MZM) and in stage 2 there is only one modulator (MZMd), connected to three pulse generators: Non-Return-to-Zero (NRZ), Return-to-Zero (RZ) and Gaussian, which were selected individually to each simulation in optisystem software. A single-mode fiber (SMF) and optical filter Gaussian (GOF) and an erbium-doped fiber amplifier (EDFA) were also used to send signals to base stations (BSs). The numerical analyzes of the results of the eye diagrams showed excellent bit error rate (BER) and quality factor (Q-factor) values, which proved the good performance of the proposed RoF- DP-MZM system, for the three encoding formats used, which was able to generate 3-tupling mm-wave for multiple wireless accesses.