The Transmission Control Of DWDM High Rate And Multi-channel QPSK System Based On DMS

In modern optical dense-wavelength-division-multiplexed (DWDM) system, the dispersionmanaged soliton (DMS) performance achieves stable transmission. The signal to noise ratio ofDMS optical pulse which is less vulnerable to the interaction from neighboring channels is high.The optical quadrature phase shift keying (QPSK) modulation format is easily to achieve higherspectral efficiency. The envelope of the QPSK signal remains constant associated with DMSshape-preserving in the transmission, thus the phase of DMS optical pulse enable QPSK signal torealize stable transmission over long distance. DMS transporting QPSK optical signal has gainedconsensus recently on rapid improvements in the spectral efficiency and anti-jamming of opticalcommunications systems. As a result, it is widely applied to high-speed DWDM communicationsystem.In this thesis, the mathematical model of QPSK transmission system based on DMS isdiscussed firstly and transmission control of the soliton communication system is analyzed. Thenthe nonlinear Schr dinger (NLS) equation is solved by the use of the variational approach underthe condition of interaction between neighboring DWDM channels. In DWDM and opticaltime-division-multiplexing (OTDM) system, the evolution equation of phase performance versusdistance of QPSK transmission system based on DMS is deduced, etc. The control method offrequency-guiding filtering is proposed to suppress the channel interaction, realizing QPSKtransmission system based on DMS stable transmission. Based on the above equations, analyticrecurrence relations to the phase of QPSK transmission system based on DMS though every fiberlink are obtained, etc. The phase jitter of QPSK transmission system based on DMS is studiedwith the impairment of the amplified spontaneous emission (ASE) added at the amplifiers. Finallythe25GBaud/s QPSK transmission system based on DMS in DWDM system is designed and itsperformance is numerically simulated. The simulation results are in well accordance with thetheoretical analysis.