Design and Simulation of OFDM-PON Combined with Polarization Multiplexing and Coherent Detection

This paper proposes a passive optical network unit structure based on orthogonal frequency division multiplexing, which combines polarization multiplexing and coherent detection techniques. In optical line terminal, quadrature amplitude modulation intensity-modulated orthogonal frequency-division multiplexing signals at 10 Gb/s are utilized for x-polarized downstream transmission. After fiber transmission, unmodulated y-polarized light in the optical network unit can be used not only as a local oscillator for downstream signal demodulation, but also as a source for upstream 2.5 Gb/s on-off keying signals. In this architecture, Time Division Multiple Access is used for upstream multiplexing transmission to achieve optimal compatibility and low cost. The performance of the proposed system is demonstrated by bit error rate and constellation diagram.