Low-Complexity Chromatic Dispersion Estimation for Faster than Nyquist Coherent Optical Systems

In this paper, a low-complexity chromatic dispersion (CD) estimation scheme is proposed for Faster than Nyquist Wavelength Division Multiplexing (FTN-WDM) coherent optical transmission systems. The computational complexity (CC) is approximately reduced by about 97.3% compared with blind CD estimation (CDE) scheme on the basis of Fractional Fourier transform (FrFT) with comparable estimation accuracy, and the CDE error of the proposed algorithm is only 65ps/nm even under low acceleration factor in FTN-WDM DP-16QAM systems. In the FTN DP-16QAM/QPSK experiments, the largest deviation of CDE is only about 70ps/nm which confirms the performance of the CDE scheme we proposed.