Simple and spectrally-efficient design of high capacity hybrid WDM/TDM-PON with improved receiver sensitivity

A simple design of hybrid wavelength division multiplexed/ time division multiplexed passive optical network (WDM/ TDM-PON) is demonstrated for the high capacity next generation access (NGA) network, having advantages of both WDM and TDM based PON techniques. A 10 Gbit/s differential quadrature phase shift keying (DQPSK) data signal is used at optical line terminal (OLT) for downstream, whereas a 2.5 Gbit/s inverse return-to-zero (IRZ) data signal with high extinction ratio is used for upstream signal by intensity re-modulation of downstream signal, no additional laser is used at optical network unit (ONU). Simulation results verify that aggregated 100 Gbit/s downstream transmissions of 10 DQPSK channels and aggregated 25 Gbit/s upstream transmission of 10 IRZ channels, using spectrally-efficient 50 GHz channel spacing, can be successfully achieved over a distance of 20 km with less than 1 dB transmission power penalties and improved receiver sensitivity.