Karsten Schuh

Experimental demonstration of nonlinear frequency division multiplexed transmission

We experimentally demonstrate an NFDM optical system with modulation over nonlinear discrete spectrum. Particularly, each symbol carries 4-bits from multiplexing two eigenvalues modulated by QPSK constellation. We show a low error performance using NFT detection with 4Gbps rate over 640km.

512-Gb/s DP-16-QAM field trial over 734 km installed SSMF with co-propagating 10 Gb/s NRZ neighbors incorporating soft-FEC decoding

We report on a 512-Gb/s dual-carrier DP-16-QAM long haul field trial over 734 km of dispersion compensated SSMF with 10-Gb/s neighbors. Soft FEC decoding was utilized in the receiver DSP confirming successful transmission.

Hybrid modulation formats outperforming 16QAM and 8QAM in transmission distance and filtering with cascaded WSS

We developed time-domain hybrid-modulation with adaptive symbolrates to optimize the reach and margin of WSS routed 400 Gb/s systems. Experimental comparisons show, that a DP-8QAM/16QAM hybrid format can outperform the benchmark DP-8QAM and DP-16QAM formats in distance when up to 18 WSS are incorporated.

5 × 50 Gb/s WDM transmission of 32 Gbaud DP-3-PSK over 36,000 km fiber with spatially coupled LDPC coding

A novel 3-PSK modulation format with 2 dB SNR gain over BPSK is implemented for ultra long haul transmission. With spatially coupled LDPC coding, 50% reach extension is achieved leading to 36.000 km transmission distance.

Optimization of time-division hybrid-modulation and its application to rate adaptive 200Gb transmission

We are optimizing time-domain hybrid-modulation with rate adaptive sFEC to implement a variable reach 200Gb/s system. Optimizations exhibit best performance at constellation scaling factors at 1.1. A reduction of FEC overhead by 8 and 16% lead to a reach reduction of 12 and 37% only.

16 x 112 gb/s nrz-dqpsk lab experiments and wdm field trial over ultimate metro distances including high pmd fibers

A 16 × 112 Gb/s field transmission trial was successfully performed over legacy fiber infrastructure of Deutsche Telekom comprising partially high polarization mode dispersion (PMD) values of 8 ps. Using a commercial PMD compensator, transmission over high PMD with negligible penalty was achieved. Enabled by the maturity of 43 Gb/s components, a 112 Gb/s nonreturn to zero (NRZ) differential quadrature phase-shift keying modulation format for dense wavelength division multiplexing transmissions with good system margins of 5 dB over 450 km metro distances (3 dB over 764 km) was demonstrated. By using high baud rate of 56 Gbd, penalty-free transmission is performed when copropagating with either 10.7 Gb/s NRZ or 43 Gb/s phase-shaped binary transmission signal channels.

On spectral phase estimation of noisy solitonic transmission

We consider the coherent transmission of soliton pulses over a long noisy optical link. We propose an efficient estimation of the transmitted nonlinear spectral phase based on Minimum Mean Square Error estimation of the eigenvalues trajectory.

Practical implementation of nonlinear fourier transform based optical nonlinearity mitigation

This tutorial provides an introduction into the application of NFT in coherent transmission systems. It summarizes concepts for modulation, transmission, and detection of signals nonlinear spectrum with an emphasis on experimental realization.

WDM field trial over 764 km SSMF with 16 × 112 Gb/s NRZ-DQPSK co-propagating with 10.7 Gb/s NRZ

A 16×112Gb/s field trial was performed at the Deutsche Telekom fiber infrastructure with partially high PMD. Using 56Gbaud NRZ-DQPSK, no penalty could be observed when co-propagating with a 10.7Gb/s NRZ. Robust Metro DWDM transmission with attractive carrier-grade margins is demonstrated.

8×107 Gbit/s serial WDM field trial over 500 km SSMF

8×107Gbit/s DWDM transmission is achieved over a 500km field installed fibre link in the Deutsche Telekom network, indicating high link utilization of 1bit/s/Hz spectral efficiency, needed for Terabit/s network capacity, required in a mid-term timeframe.