Modelling and simulation of high-speed direct detectionopticalfibre communication systems

摘要

A simulation strategy suitable for performance assessment oflong-haul high-bit-rate direct-detection systems is presented.Particular consideration is given to the interaction with fiberdispersion of laser modulation phenomena such as frequency chirp andpatterning which exhibit complex nonlinear data dependence. Thenonlinear modulation response of the laser transmitter is taken intoaccount by using pseudo-random data sequences to estimate thedispersion-induced performance degradation. The dependence of themodulation and dispersion-induced penalties on the extinction ratio ofthe laser emission is shown for the specific case of 4 Gb/s NRZmodulation and a total dispersion L×D=1 nsm.With this approach, the implications for system performance of the laseroperating point, modulation format used, receiver filter bandwidth, andtiming acquisition imperfections are investigated, and some performancelimitations are indicated