Junichi Abe

Fast optical channel recovery in field demonstration of 100-Gbit/s Ethernet over OTN using real-time DSP

A field trial of 100-Gbit/s Ethernet over an optical transport network (OTN) is conducted using a real-time digital coherent signal processor. Error free operation with the Q-margin of 3.2 dB is confirmed at a 100 Gbit/s Ethernet analyzer by concatenating a low-density parity-check code with a OTN framer forward error correction, after 80-ch WDM transmission through 6 spans x 70 km of dispersion shifted fiber without inline-dispersion compensation. Also, the recovery time of 12 msec is observed in an optical route switching experiment, which is achieved through fast chromatic dispersion estimation functionality.

112Gb/s optical transponder with PM-QPSK and coherent detection employing parallel FPGA-based real-time digital signal processing, FEC and 100GbE Ethernet interface

We demonstrate 112Gb/s transmission using PM-QPSK format and FPGA-based real-time digital signal processing. By employing framed processing architecture for polarization demultiplexing and carrier phase estimation, stable operation of error free after FEC and wide frequency offset have been achieved.

Experimental demonstration of the improvement of system sensitivity using multiple state trellis coded optical modulation with QPSK and 16QAM constellations

We evaluated experimentally 2, 8, 32 state 32Gbaud TCM-QPSK and TCM-16QAM. TCM offers finer configuration for flexible transponders increasing SE, on 1.1dB wider ranges. TCM may also be used with HD-FEC in lower power transceivers.

Long Haul transmission of four-dimensional 64SP-12QAM signal based on 16QAM constellation for longer distance at same spectral efficiency as PM-8QAM

We propose a new 4D coded modulation format, 64SP-12QAM, with same SE as PM-8QAM and straightforwardly-switchable with PM-16QAM. We experimentally demonstrated over 0.2 dB better sensitivity for 64SP-12QAM compared to PM-8QAM, enabling a transmission reach extension to 6,000 km at 6b/s/Hz.

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.

Hardware-efficient multi-redundancy superposed trellis coded modulation on 16QAM constellation

We propose multi-redundancy optical coded modulation using superposed trellis. We experimentally prove that our scheme enables fine adaptive SE control and high coding gain of 7.1dB for 3-bit redundant 16QAM with quarterly reduced circuit complexity.

High-speed and simple estimation algorithm of waveform distortions using a 43-Gb/s SiGe-based eye-Monitoring LSI

We propose a high-speed and simple estimation algorithm of waveform distortions using a 43-Gb/s SiGe-based eye-monitoring LSI, and experimentally demonstrate precise estimations of PMD and chromatic dispersion.

Demonstration of the improvement of transmission distance using multiple state trellis coded optical modulation

We demonstrated experimentally the improvement of the transmission distance by 27% of 150Gb/s signal at 3b/s/Hz with a novel TCM format, 8-state 12QAM TCM, compared to PM-8QAM. We also demonstrated improvement of the transmission distance for multiple state TCM using nonlinear compensation, ranging from 14% to 26%, while similar improvement was below 11% for PM signals.

Experimental investigation of adaptive electrical dispersion compensation using eye monitoring LSI in 43 Gbit/s RZ-DPSK signal

We propose an adaptive electrical dispersion compensation using newly developed high-speed eye monitoring LSI, and demonstrated experimentally the effective enlargement of PMD tolerance in 43 Gbit/s RZ-DPSK signal.