Multi-Level Mapping for Long Haul Coherent Optical OFDM Systems
Recently, Coherent Optical Orthogonal Frequency Division Multiplexing (CO-OFDM) has been seen as a potential candidate for long haul optical transmission. It is due to OFDM technique that was proved as an effective solution for mitigating Chromatic Dispersion (CD) effects in optical communication systems. The CO-OFDM systems of 40Gb/s and 100 Gb/s per channel can use multilevel mapping to increase spectral efficiency. This paper presents an implementation of OFDM transmitter and receiver using QPSK and 16-QAM mapping. The transmitter is to generate the orthogonal signals for optical modulators, and the receiver detect the signals after the optical receiver then to recover orginal signals.