Performance evaluation of a single mode-multi mode cost efficient fiber link used for 4/16/64 QAM gigabit OFDM MMW transmission using different MZM modulation schemes

Chromatic dispersion in single mode fibers (SMF) and Inter-Modal Delay Dispersion (IMDD) in multimode fibers (MMF) severely limits the transmission link distance. With data rates approaching 10Gb/s, the transmission distance of MMF is limited up to few meters. In this paper, we simulate a simple and cost effective Passive Optical Network (PON) by combining SMF-MMF Radio over Fiber (RoF) link using central launching technique at 1550nm. The system targets the transmission of 2 & 5Gb/s Optical Orthogonal Frequency Division Multiplexing (OFDM) with 4/16/64 QAM modulation formats over already installed MMF. The optical up-conversion of millimeter wave is performed by Mach Zehnder Modulator (MZM) using different modulation schemes. The performance limitation imposed by chromatic and intermodal dispersion due to coupling of SMF-MMF (over 20kms and upto 1km respectively) is analysed by varying the modulation formats of QAM-OFDM along with different MZM upconversion techniques.