Ted Schmidt

Ultra high speed optical transmission using subcarrier-multiplexed four-dimensional LDPC-coded modulation

We propose a subcarrier-multiplexed four-dimensional LDPC bit-interleaved coded modulation scheme that is capable of achieving beyond 480 Gb/s single-channel transmission rate over optical channels. Subcarrier-multiplexed four-dimensional LDPC coded modulation scheme outperforms the corresponding dual polarization schemes by up to 4.6 dB in OSNR at BER 10(-8).

DPSK Receiver Design - Optical Filtering Considerations

We study via simulation the influence of the DPSK decoder free spectral range (FSR) when strong optical filtering is considered for the NRZ and RZ modulation formats and show that larger FSR can improve performance.

Efficient, non-data-aided chromatic dispersion estimation via generalized, FFT-based sweep

We propose a method that eliminates the 2 samples/symbol requirement on FFT-based CD estimation, and generalizes this highly-efficient, non-data-aided, frequency-domain CD estimation approach to systems with η samples/symbol where 1<;η ≤2.

43Gb/s Adaptive Polarization Mode Dispersion Compensator Field Trial

We describe long-term field measurements at 43Gb/s over a high-PMD link, using one receiver with adaptive PMD compensation and a second receiver without. The Q at both receivers is monitored and correlated with instantaneous DGD.

Transmission of 40 Gbps signals through metropolitan networks engineered for 10 Gbps signals

A critical emerging technology for advanced DWDM systems is 40 Gbps transmission support. The use of 40 Gbps channels increases the DWDM capacity by the factor of four, supports interconnection of next generation IP routers at OC-768 and saves OpEx and CapEx due to having to deploy and maintain fewer channels to provide the same capacity, needing fewer spare transponder modules. A key design driver for 40 Gbps technology is that it should seamlessly integrate with existing 10 Gbps systems without requiring changes to the common equipment, including ROADM technology. Parameters that must be analyzed to a greater degree at the 40 Gbps transmission rate include chromatic dispersion, PMD, and filtering effects. This analysis is based on the experiment on deployment of 43 Gb/s PSBT signals over an existing 10 Gb/s DWDM system with cascaded ROADMs that we reported on last year (M. Boduch et al., 2005).

Mitigating channel impairments in high capacity serial 40G and 100G DWDM transmission systems

A perspective on impairment mitigation strategies is provided for past, present, and future commercial 40G deployments. Requirements for practical 100G deployments are ascertained from commercially successful 40G solutions, where seamless upgrade to existing 10G systems was a key requirement. Options meeting these requirements are explored.

Three-dimensional nonbinary-LDPC-coded modulation schemes for high speed optical fiber transmission

We propose coded-modulation schemes employing three-dimensional constellations and component nonbinary LDPC codes to enable high-speed optical communications. Compared to polarization-division-multiplexed QPSK, the proposed scheme improves coding gain by ~2dB even at the BER of 10-6.

40G and 100G modules enable next generation networks

With the wide scale deployment of 40Gbps in carrier networks underway and 100Gbps products on the horizon, 40Gbps and 100Gbps modules based on Multi Source Agreements (MSA) are gaining considerable interest and market acceptance. This paper discusses developments in 40Gbps and 100Gbps line side DWDM MSA modules and CFP based client side MSA modules as suppliers strive to address various system and network applications.

Practical limits of coherent receivers for unamplified 100Gb/s applications

The impact of noise sources on the performance of a coherent receiver for loss-limited links is demonstrated. With GFEC, -29.1dBm receiver sensitivity is achieved for 112-Gb/s PM-QPSK format. For shared laser architectures, asymmetric power splitting favoring the transmitter is shown to result in optimum link budget.

100G coherent DWDM transponder module enabling seamless upgrade of long haul optical transmission systems

We review recent trends and progress in 100G module development for long haul DWDM applications. Special attention is paid to properties enabling seamless upgrade of existing long haul transmission systems.