A novel DSP scheme for eliminating the interaction between dispersion and transient frequency offset in optical burst-mode coherent systems

Abstract Optical coherent burst-mode transmission can offer not only flexibility but also efficiency of the network resource utilization in elastic optical networks. We propose a new digital signal processing (DSP) scheme of coherent burst reception with a training sequence (TS) to solve the convergence problem of equalization caused by the interaction between fast-changing transient frequency offset (TFO) and fiber chromatic dispersion (CD) compensation in optical burst (OB)-mode systems. The DSP scheme is demonstrated to perform well by the simulation and experimentation on 128 Gbps polarization multiplexing quadrature phase-shift keying (PM-QPSK) coherent systems. Thanks to the DSP scheme, a guard interval between two OBs is no longer needed, and the valid payload can be transmitted during TFO changing from wavelength tuning. The proposed DSP scheme can reduce the overhead by ∼ 73% for wavelength-tunable OB-mode coherent systems compared with using guard intervals, which significantly improves the spectral efficiency of burst-mode systems.