100 Gbps long reach coherent PON downstream transmission using dual polarization-QPSK with digital signal processing

This paper demonstrates 100 Gbps long reach coherent passive optical network (CPON) downstream transmission on a single wavelength over 100 km with 1:128 power split having acceptable performance. Here dual polarization-quadrature phase shift keying modulation format is utilized for transmission in the central office and digital signal processing (DSP) is utilized at the optical network unit (ONU) to compensate the linear impairments generated due to high speed optical signal transmission over standard single mode fiber. At the receiving end (ONU), homodyne coherent detection is utilized. The DSP is done using MATLAB and executes five functions that are analog to digital conversion, chromatic dispersion compensation, polarization demultiplexing, carrier phase estimation and digital to analog conversion. The results of proposed architecture are verified in terms of constellation diagrams and receiver sensitivity. The simulated results indicate that our proposed 100 Gbps long reach CPON downstream transmission is feasible and may be implemented in next generation high speed PONs.