373 research outputs found
11 x 224 Gb/s POLMUX-RZ-16QAM transmission over 670 km of SSMF with 50-Ghz channel spacing
We demonstrate the generation and transmission of eleven channels with 224-Gb/s polarization-multiplexed, return to zero, 16-level quadrature amplitude modulation (POLMUX-RZ-16QAM) over 670 km of standard single mode fiber (SSMF) with 50-GHz channel spacing and a spectral efficiency of 4.2 b/s/Hz. We report a penalty of around 4.3 dB in the performance at back-to-back in comparison to the theoretical limits, and a margin of 1 dB in Q-factor below the forward error correction (FEC) limit (assumed to be at a bit error rate of 3.8x10-3) after transmission over 670 km of SSMF
Transmission of 11 x 224 Gb/s POLMUX-RZ-16QAM over 1500 km of LongLine and pure-silica SMF
We demonstrate transmission of 11 x 224-Gb/s POLMUX-RZ-16QAM over 1500 km with a channel spacing of 50 GHz. A hybrid configuration of LongLine and pure silica fiber is used to optimize both nonlinear tolerance and Raman gain.</p
Reduction of Gordon-Mollenauer phase noise by midlink spectral inversion
We show that spectral inversion can be employed for regeneration to reduce the effect of phase noise (Gordon-Mollenauer phase noise) in a nonreturn-to-zero differential phase-shift-keying based transmission system. Several locations of the spectral inverter in an eight-span transmission link have been investigated. We show that the best results are obtained when the spectral inverter is placed in the middle of the link. Compared to the transmission system without spectral inverter, an improvement of over four decades in bit-error-rate performance is achieved
SISTA South Africa: The adaptation of an efficacious HIV prevention trial conducted with African-American women for isiXhosa-speaking South African women
Although new HIV treatments continue to offer hope for individuals living with HIV, behavioural interventions shown to reduce HIV risk behaviour remain one of the most powerful tools in curbing the HIV epidemic. Unfortunately, the development of evidencebased HIV interventions is a resource-intensive process that has not progressed as quickly as the epidemiology of the disease. As the epidemic continues to evolve, there is a need to expedite the development of evidence-based HIV interventions for populations
that are often disproportionately impacted by HIV/AIDS. One mechanism of accelerating the development process is to adapt evidence-based HIV interventions for vulnerable populations. The aim of this paper was to describe the adaptation process of a HIV intervention for African-American women for black South African Xhosa women. For African-American women the intervention was effective in increasing consistent condom use, sexual self-control, sexual communication, sexual assertiveness and partner adoption of norms supporting consistent condom use. Keywords: Intervention, women, cultural adaptation, HIV transmission risk behaviours.SAHARA-J Vol. 5 (4) 2008: pp. 186-19
111 Gb/s transmission with compensation of FBG-induced phase ripple enabled by coherent detection and digital signal processing
We demonstrate that coherent detection combined with digital signal processing can completely compensate for FBG induced phase-ripple. We report penalty free transmission of 40×111-Gb/s POLMUX-RZ-DQPSK over 1,425-km of SSMF with FBG for in-line dispersion compensatio
10x224-Gb/s POLMUX-16QAM transmission over 656 km of large-Aeff PSCF with a special efficiency of 5.6 b/s/Hz
We demonstrate the successful transmission of 10 channels with 224-Gb/s POLMUX-16QAM modulation (28 GBaud) on a 37.5-GHz wavelength grid. Using large-Aeff pure-silica-core fibers we show a 656-km transmission distance with a spectral efficiency of 5.6 b/s/Hz. We report a back-to-back performance penalty of 3.5 dB compared to theoretical limits at the forward-error correction (FEC) limit (bit-error rate of 3.8·10-3), and a margin of 0.5 dB in Q-factor with respect to the FEC-limit after 656 km of transmission
A comparison between SSMF and large-Aeff Pure-Silica core fiber for Ultra Long-Haul 100G transmission
We compare the transmission performance of 112-Gb/s POLMUX-QPSK modulation over large-Aeff Pure-Silica core fiber and SSMF using EDFA-only amplification. The higher nonlinear threshold of the large-Aeff Pure-Silica core fiber allows for a 55% increase in transmission distance. By using back-propagation an additional 10% increase is observed. In case spans with equal length for both fiber types and two splices per span only would have been used, resulting in a lower span loss for the large-Aeff Pure-Silica core fiber, the total increase grows to 85%
Maximum-Likelihood Sequence Estimation for Optical Phase-Shift Keyed Modulation Formats
111-Gb/s POLMUX-RZ-DQPSK Transmission over LEAF: Optical versus Electrical Dispersion Compensation
We investigate the transmission performance of 111-Gb/s POLMUX-RZ-DQPSK modulation using either optical or electrical dispersion compensation. We show that after 2000-km LEAF transmission both link configurations have a comparable nonlinear tolerance
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