Shinsuke Fujisawa

Hardware-efficient polarization demultiplexing for QAM signals based on dual stage decision-directed algorithm

We propose a hardware-efficient polarization demultiplexing algorithm suitable for QAM signals, which is based on dual decision-directed algorithm. Our algorithm requires only half size hardware of a conventional double stage algorithm based on CMA.

Mitigation of intra-channel nonlinear distortions based on PAPR reduction with CD pre-compensation in real-time 50Gbps PM-QPSK transmission

We verified the correlation between PAPR and intrachannel nonlinear distortions with 50.7Gbps PM-QPSK signal over 1,310km dispersion non-managed transmission. Experimental results with 50% CD pre-compensation exhibited minimal PAPR and improved Q factor.

Enhancing protection performance by effectively using spectral slots of impairment-aware elastic optical networks [invited]

The challenge of using spectral bandwidth effectively considering optical impairments in elastic optical networks is studied. The protection performance is enhanced by improving the spectral efficiencies of the networks. Novel optical filter configuration, signal equalization, and spectral bandwidth assignment technologies are proposed to minimize the use of the guardband while taking the passband narrowing effect into consideration. It is verified that spectral slots are effectively used with actual network topology models.

Reliability enhancement by a joint optimization of elastic optical path allocation methods

Increasing the number of lightpaths for protection accommodated onto an optical fibre network improves reliability of communication services. For this purpose, more optical paths can be accommodated by a spectrally efficient path assignment algorithm, while keeping spectral efficiency of the optical path higher. In this paper, we propose a joint optimization of elastic optical path allocation methods. The simulation results show that the joint optimization algorithm achieves reliability enhancement.

Experimental verification of minimum overlap size design in a FDE-based chromatic dispersion compensation circuit with a 50Gb/s PM-QPSK signal

We propose a simple design method of minimum overlap data size for overlap-FDE based CD compensation. We confirmed its validity using a real-time DSP circuit and 50.7Gbps PM-QPSK signal for up to 56,200ps/nm.