Nonlinear effects compensation in Optical Coherent PDM-QPSK Systems

Abstract

Nonlinear effects has been appointed as the main limitation in coherent optical fiber transmission. Digital Back-Propagation algorithms and Maximum Likelihood Sequence Estimation are two of the current studied methods to cope with such impairment and extend the systems maximum reach. In this article, we analyzed both methods in a 112 Gb/s Dual Polarization Quadrature Phase Shifting Keying (DP-QPSK) optical coherent system through simulations and experimental results. In order to reduce the huge required computational complexity, a modified back-propagation algorithm is also analyzed.

Effect of layered hydroxide salts, produced by two different methods, on the mechanical and thermal properties of poly(methyl methacrylate)

“…3). These basal spacings values are in agreement with those previously reported in literature for LDH(azelate) (11.8 Å, 13.5 Å, and 16.6 Å) [3,13]. The largest calculated distance that the ion azelate can occupy is 12.3 Å.…”

“…Considering the basal spacing of 16.7 Å, an interlayer spacing of 11.9 Å is obtained which is consistent with the presence of azelate ions between the inorganic layers, oriented almost perpendicularly with respect to the layers' planes. Because azelate di-anion is formed by long carbon chain, different bending possibilities can fit in the interlayer space, thus leading to further orientation of the guest molecules [13].…”

Link Optimization and Performance Analysis of a 40 Gbps DQPSK Modulated Ultra DWDM System with 32 Orthogonally Polarized channels

“…There are two different approaches to demodulate the DQPSK signal, the first one is to receive the DQPSK format with differential direct detection receivers which requires efficient dispersion compensation and tight filtering. The second approach uses coherent receivers combined with electronic dispersion compensation (EDC) exploiting DSP capabilities for practical implementation [35]. As the phase information is preserved in the coherent systems, coherent systems offer more options such as PM-QPSK (polarization-multiplexed quadrature phase-shift keying), PS-QPSK (polarization-switched quadrature phase-shift keying), PM-16QAM (Polarization-Multiplexed Quadrature Amplitude Modulation) and DP-QPSK (Dual-Polarization quadrature phase shift keying) [36][37][38].…”

“…Moreover, coherent fiber optic systems involving homodyne or heterodyne detection schemes have also been extensively explored [35,36]. The high receiver sensitivity offered by these systems motivated a huge surge in their demand but were not commercialized due to costly and complex components and challenges in the proper design of optical phase locked loops (PLLs) .…”

Analysis of Nonlinear Signal Interference to Optimize the Coherent Optical Transmission System

“…Like submarine link, for higher line rate, COTS plays an important job for lower cost information transmission because of DWDM and EDFA in the transmitter and the chain of the link respectively. Consequently, optimization is an important issue to upgrade and minimize the higher cost of the existing optical network considering higher modulation formats [4]. The performance of COTS is also obtained through the improvement of the nonlinear optical signal propagation.In this regard, we have considered four GN models on multiple identical spans, non-Nyquist WDM system, non identical spans and multi-channels.…”