Xiangye Zeng

Analysis of a modified adaptive least mean square frequency-domain algorithm for equalization in polarization division multiplexed-mode division multiplexed fiber transmission

Mode division multiplexed(MDM) in few mode fibers has gained attraction due to its potential to achieve ultrahigh capacity beyond the nonlinear Shannon limit of the single mode fiber. However, it cannot be ignored that the effect of crosstalk, mode coupling and differential mode group delay on optical signals exists in transmission and equalizing these impairments are required in the digital signal processing(DSP). In this paper, a modified frequency domain least mean square(LMS) algorithm as the adaptive algorithm is proposed for the digital dispersion equalizer of polarization multiplexed few mode fiber MDM coherent single-carrier system. The simulation results show that the modified algorithm can improve the clarity of constellation and get better equalization performance comparing to the traditional algorithm.

PAPR reduction technology based on CSO algorithm in CO-OFDM system

We propose a new method to reduce peak to average power ratio (PAPR) in CO-OFDM system by applying chicken swarm optimization (CSO) algorithm to optimize the initial phase of the subcarriers. Stimulation result shows that PAPR of CSO optimized signal is reduced by 5.5dB and 1.5dB compared with that of original signal and particle swarm optimization (PSO) optimized signal and BER performance is improved.

A Method of Combining PPC and ACE to Reduce PAPR in CO-OFDM System

A method combining PPC and ACE is proposed, and uses constellation point pre-adjustment to further reduce the PAPR. When CCDF is10-3 , approximately 4.2dB improvement in PAPR is achieved with no BER degradation.

Comparison of swarm intelligence methods for suppressing PAPR in CO-OFDM systems

Swarm intelligence algorithms are applied to suppressing peak to average power ratio (PAPR) in CO-OFDM system by optimizing phase of subcarriers. The result shows that all of these algorithms can effectively reduce PAPR, and the PAPR of CSO optimized signal is reduced by 1.5dB, 0.77dB and 0.28dB compared with that of PSO, BSA and BA optimized signals.

Research on timing synchronization algorithms for CO-OFDM systems

A timing synchronization algorithm with a new timing metric function is proposed for CO-OFDM system. Simulation results show that the MSE of the proposed algorithm is very close to zero in the system without chromatic dispersion, even though the OSNR is low. And it can provide higher accuracy comparing with other methods when the dispersion reaches 18ps/nm/km.

Polarization de-multiplexing algorithm based on twice real-valued FastICA (invited)

Twice real-valued FastICA (TR-FastICA) algorithm is proposed in this paper to eliminate crosstalk between the two polarization multiplexed complex-valued higher-order quadrature modulation format such as QPSK signals induced by polarization mode coupling with polarization mode dispersion (PMD) and polarization dependent loss (PDL) for the coherent optical polarization division multiplexing (CO-PDM) system. The proposed algorithm has much lower computation complexity meaning simpler hardware implementation compared with algorithm based on complex maximization of non-Gaussianity (CMN). Simulation results show that the proposed TR-FastICA algorithm can eliminate crosstalk between the two polarization signals effectively and improve the transmission performance.

Polarization insensitive wavelength conversion based on orthogonal pump for polarization multiplexing 16-QAM OFDM signal

The system based on orthogonal pump four-wave mixing in an SOA is theoretically analyzed and simulated. The simulation results show that the polarization insensitive converted signal can be separated into two lightwaves without crosstalk.