排序方式: 共有3条查询结果,搜索用时 9 毫秒
1
1.
A closed-form bit-error rate (BER) expression is derived for free-space optical (FSO) communication systems with circle polarization shift keying and spatial diversity receivers in the gamma-gamma (GG) distribution fading channel. This model can predict the performance without the need of lengthy simulation runs. The performance can be analyzed by some system parameters such as atmospheric conditions, link length, communication wavelength, receiver aperture size, and number of spatial diversity receivers. Numerical results demonstrate the influence of the above parameters on the FSO systems and show quantitatively the differences in behavior among various different parameters. 相似文献
2.
提出一种双边缘测风激光雷达法布里-珀罗(F-P)干涉仪鉴频器的非线性比例-积分-微分(PID)控制方法。该方法利用发射激光在鉴频器校正通道的透过率作反馈进行F-P干涉仪鉴频器的稳定控制。首先给出F-P干涉仪鉴频器透过率的控制模型,由气压波动、温度变化和振动等引起的外界扰动被等效为施加在致动压电陶瓷上的扰动外力。为了进行扰动补偿,用新增的反正切函数设计了非线性PID控制器,提高了经典PID控制方法的反馈增益。仿真结果显示,与经典的PID控制相比,新的非线性控制方法可以使F-P干涉仪鉴频器在更短的时间达到稳定状态,并且稳态误差约减小到原来的1/20。 相似文献
3.
1