高速相干光通信中的多符号差分检测技术研究

Study on multi-symbol differential detection techniques for high-rate coherent optical communications

针对高速相干光通信系统中激光器相位噪声和频偏估计的补偿问题,设计了基于MSDD(多符号差分检测)的相位恢复算法,研究了在ASE(自激发射放大)噪声、激光器线宽和频偏等因素影响下的系统性能和MSDD算法的补偿能力。仿真结果表明,自适应MSDD算法对激光器线宽和频偏的补偿效果显著,对线宽为1 MHz、频偏为100 MHz的20GBaud QPSK(正交相移键控)系统,误码率为10-3时的OSNR(光信噪比)代价仅为0.6dB。

For the compensation of the laser phase noise and frequency offset estimation in high-rate coherent optical communi- cation systems, a Multi-Symbol Differential Detection （MSDD）-based phase recovery algorithm is designed and the system pero formances and MSDD compensation capabilities under the influence of ASE noise, laser linewidth and frequency offset are stud- ied. Simulation results show that this algorithm produces significant compensation effects on the laser linewidth and frequency offset. Specifically, for a 20 GBaud QPSK modulated system with 1 MHz linewidth and 100 MHz frequency offset, the OSNR penalty is only 0.6 dB when its BER is 10^-3.