A multiplier-free phase estimation algorithm based on the barycentre approach for coherent QPSK detection is presented. A selectivity mechanism was developed that significantly improved its performance. In addition to recently published measurement results, theoretical background and new simulation results are presented.
Coherent fiberoptic transmission with synchronous detection of 4, 8 or more bit/symbol enhances spectral efficiency. It relies on polarization-division multiplexing (PDM) and quadrature phase shift keying (QPSK) or higher-order quadrature amplitude modulation (QAM). A coherent polarization diversity, in-phase and quadrature receiver detects the optical… (More)
SUMMARY We present the recovery of 2.5 Gb/s synchronous 16-point quadrature amplitude modulation data in real-time for an linewidth-times-symbol-duration ratio of 0.00048 after transmission over 1.6 km standard single mode fiber. key words: optical communication, 16ary quadrature amplitude modulation , coherent communication, phase estimation, feedforward… (More)