eCLIPs bifurcation remodeling system for treatment of wide neck bifurcation aneurysms with extremely low dome-to-neck and aspect ratios: a multicenter experience

In our case series, 24 patients treated at 12 international centers were taken from a larger prospective voluntary post-marketing registry of 65 patients treated with the eCLIPs device and coiling. Those who had WNBAs at either the carotid or basilar terminus with a DTN ratio Wide necked bifurcation aneurysms (WNBA) are among the most difficult aneurysms to treat. Very low dome-to-neck (DTN) and aspect ratios provide an even greater challenge in the management of WNBAs. We present the safety and efficacy profile for endovascular clip system (eCLIPs) device in the treatment of this subset of WNBAs with very unfavorable morphologies.Our series of patients with aneurysms having adverse DTN and aspect ratios demonstrated that the eCLIPs device has a safety and efficacy profile comparable with currently available devices in the treatment of WNBAs.The eCLIPs device was successfully deployed in 23 cases (96%). One patient (4.2%) died due to guidewire perforation distal to the implant site. No other complications were documented. After a mean follow-up of 15.8 months (range 3-40 months), good radiologic outcomes (modified Raymond-Roy classification (MRRC) scores of 1 or 2) were documented in 20 of 21 patients (95%) with follow-up data. The lone patient with an MRRC score of 3 showed coiled compaction after incomplete neck coverage with the device.</div

Evaluation of correlative coding and DP-16QAM N-channel 112gbit/s coherent transmission: Digital non-linear compensation perspective

We report on the complexity reduction of digital backward propagation (DBP) by utilizing correlative encoded transmission over 1640km fiber link. Comparative system performance w.r.t DP-16QAM transmission can be achieved with 60% less computations and with a step-size of 205km. © 2012 OSA

Logarithmic step-size based digital backward propagation in N-channel 112Gbit/s/ch DP-QPSK transmission

We propose and numerically investigate logarithmic step-size distribution for implementing efficient digital backward propagation (DBP) algorithm using split-step Fourier method (SSFM). DBP is implemented in N-channel 112Gbit/s/ch dual-polarization quadrature-phase-shift-keying (DP-QPSK) transmission over 2000km standard single mode fiber (SMF) with no in-line optical dispersion compensation. This algorithm is compared with constant step-size modified DBP (M-SSFM) algorithm in terms of efficiency, complexity and computational time. Furthermore, we investigate the same-capacity and same-bandwidth-efficiency transmission systems with 28GBaud and 56GBaud per-channel rates. The logarithmic step-size based DBP algorithm depicts efficient mitigation of chromatic dispersion (CD) and non-linear (NL) impairments. Benefit of the logarithmic step-size is the reduced complexity and computational time for higher baud rates. © 2011 IEEE

Nonlinear mitigation using carrier phase estimation and digital backward propagation in coherent QAM transmission

We investigate the performance of carrier phase estimation (CPE) and digital backward propagation (DBP) in compensating fiber nonlinearity for 224Gbps PM-4QAM and PM-16QAM coherent systems. In the presence of CPE, the number of DBP steps can be reduced. © 2012 OSA

Compensation of signal distortion by optimized digital backward propagation in DQPSK transmission

We optimize digital backward-propagation (DBP) to compensate signal distortions for various launch powers and bit rates. By optimizing transmission parameters and nonlinear phase calculating point, multi-span DBP gives significant improvement. © OSA/CLEO 2011

Evaluation of correlative coding and DP-16QAM n-channel 112Gbit/s coherent transmission: Digital non-linear compensation perspective

We numerically report on the complexity reduction of digital backward propagation (DBP) by utilizing correlative encoded transmission (dual-polarization quadrature duobinary) at a bit-rate of 112Gbit/s over 1640km fibe link. The single channel (N=1) and multi-channel (N=10) transmission performances are compared in this paper. In case of multichannel system, 10 transmitters are multiplexed with 25GHz channel spacing. The fibe link consists of Large Ae f f Pure-Silica core fibe with 20 spans of 82km each. No in-line optical dispersion compensator is employed in the link. The system performances are evaluated by monitoring the bit-error-ratio and the forward error correction limit corresponds to bit-error-ratio of 3.8×103. The DBP algorithm is implemented after the coherent detection and is based on the logarithmic step-size based splitstep Fourier method. The results depict that dual-polarization quadrature duobinary can be used to transmit 112Gbit/s signals with an spectral efficien y of 4-b/s/Hz, but at the same time has a higher tolerance to nonlinear transmission impairments. By utilizing dual-polarization quadrature duobinary modulation, comparative system performance with respect to dual-polarization 16-quadrature amplitude modulation transmission can be achieved with 60% less computations and with a step-size of 205km. © 2013 Optical Society of America

Compensation of signal distortion by optimized digital backward propagation in DQPSK transmission

We optimize digital backward-propagation (DBP) to compensate signal distortions for various launch powers and bit rates. By optimizing transmission parameters and nonlinear phase calculating point, multi-span DBP gives significant improvement. © OSA/ CLEO 2011

Evaluation of correlative coding and DP-16QAM n-channel 112Gbit/s coherent transmission: digital non-linear compensation perspective

We numerically report on the complexity reduction of digital backward propagation (DBP) by utilizing correlative encoded transmission (dual-polarization quadrature duobinary) at a bit-rate of 112Gbit/s over 1640km fiber link. The single channel (N=1) and multi-channel (N=10) transmission performances are compared in this paper. In case of multi-channel system, 10 transmitters are multiplexed with 25GHz channel spacing. The fiber link consists of Large Aeff Pure-Silica core fiber with 20 spans of 82km each. No in-line optical dispersion compensator is employed in the link. The system performances are evaluated by monitoring the bit-error-ratio and the forward error correction limit corresponds to bit-error-ratio of 3.8×10−3. The DBP algorithm is implemented after the coherent detection and is based on the logarithmic step-size based split-step Fourier method. The results depict that dual-polarization quadrature duobinary can be used to transmit 112Gbit/s signals with an spectral efficiency of 4-b/s/Hz, but at the same time has a higher tolerance to nonlinear transmission impairments. By utilizing dual-polarization quadrature duobinary modulation, comparative system performance with respect to dual-polarization 16-quadrature amplitude modulation transmission can be achieved with 60% less computations and with a step-size of 205km

Nonlinear mitigation using carrier phase estimation and digital backward propagation in coherent QAM transmission

We investigate the performance of carrier phase estimation (CPE) and digital backward propagation (DBP) in compensating fiber nonlinearity for 224Gbps polarization-multiplexed quadrature-amplitudemodulation coherent systems with level of 4 and 16 (PM-4-QAM and PM-16-QAM) over standard single-mode fiber (SSMF) uncompensated link. The results from numerical simulation show the individual performance of CPE and DBP as well as their mutual influence. With DBP compensation, required CPE tap number for optimal performance can be reduced by 50% for 4-QAM signal and 67% for 16-QAM signal compared to linear compensation. On the other hand, employing CPE compensation after DBP also allows to reduce DBP steps. In the mentioned PM-16-QAM system, 60% reduction in the required number of DBP steps to achieve BER=10-3 is possible, with a step-size of 200km, which reveals great potential to reduce the complexity for future real time implementation. © 2012 Optical Society of America

Compensation of signal distortion by optimized digital backward propagation in DQPSK transmission

We optimize digital backward-propagation (DBP) to compensate signal distortions for various launch powers and bit rates. By optimizing transmission parameters and nonlinear phase calculating point, multi-span DBP gives significant improvement. © OSA/CLEO 2011