Performance analysis of coherent optical communication system for higher order dual polarization modulation formats

The ever increasing demand of data traffic due to emerging services and applications has evolved the need of high capacity, high speed and highly spectral efficient optical systems with advanced modulation formats. We compare the performance of single channel coherent optical system for 112 Gb/s with Dual polarization modulation techniques i.e. DP- QPSK(Dual Polarization Quadrature phase shift keying), DP-16QAM(Dual Polarization −16 Quadrature amplitude Modulation) and DP-32QAM(Dual Polarization −32 Quadrature amplitude Modulation) with DSP (Digital Signal Processing)module for SSMF(standard single mode fiber) in terms of tolerance to fiber nonlinearities which is investigated through the effect of power and distance on %EVM and requirement of OSNR using numerical simulations. ned shows that the coherent optical systems with higher order modulation formats are less tolerant to fiber nonlinearities i.e the performance of DP-QPSK coherent systems with DSP module is better than the DP-16QAM and DP-32QAM coherent systems as they are more tolerant to fiber nonlinearities. The results obtained can be used for the design of compensation techniques for fiber nonlinearities in cohResults obtaierent optical systems using higher order modulation formats.