2DPSK和4DPSK系统的色散比较

2DPSK vs. 4DPSK: comparison of dispersion tolerances

研究了不归零2DPSK和4DPSK系统的色度色散(CD)和一阶偏振模色散(PMD)，综合放大器噪声、脉冲波形和光／电滤波器，以及系统存在的彩色色散和一阶偏振模式色散等因素，建立了DPSK系统模型，仿真计算了线性传输系统的光功率损耗，结果表明，4DPSK系统的色度色散和一阶偏振模色散的功率损耗比2DPSK系统更低。

This paper studies the impact of chromatic dispersion （CD） and first-order polarization-mode dispersion （PMD） on binary differential phase-shift keying （2DPSK） or quaternary DPSK （4DPSk） systems with nonretumto-zero （NRZ） formats. Taking account of amplifier noise, pulse shapes, optical and electrical filtering, CD, and PMD, a mathematical model is firstly established, then the simulation is made with a linear transmission system and optical power loss is evaluated. The results show that 4DPSK exhibits lower CD and PMD power loss than 2DPSK.