频谱弥散(SMSP)干扰是一种针对线性调频(LFM)信号的相参压制干扰。根据SMSP干扰子脉冲的周期特性,提出了一种基于干扰重构和峭度最大化的干扰抑制方法。首先,利用自相关方法估计干扰子脉冲的周期,并根据干扰的产生原理确定子脉冲调频斜...频谱弥散(SMSP)干扰是一种针对线性调频(LFM)信号的相参压制干扰。根据SMSP干扰子脉冲的周期特性,提出了一种基于干扰重构和峭度最大化的干扰抑制方法。首先,利用自相关方法估计干扰子脉冲的周期,并根据干扰的产生原理确定子脉冲调频斜率,即可重构相位未知的干扰子脉冲;其次,对重构的干扰子脉冲分别设定不同的相位,并与接收信号做共轭相乘,根据相乘的结果确定干扰信号的初相位;最后,利用峭度最大化原理,确定干扰抑制因子,实现干扰抑制。仿真结果表明,本文方法能够有效实现干扰抑制,经过干扰抑制后的信干比可达20 d B以上,并且在存在噪声和相位误差的情况下,仍能够保持较高的信干噪比增益。展开更多
A novel single-mode single-polarization （SMSP） photonic crystal fibre has been proposed and analysed based on the polarization-dependent coupling and absorption effect via a full-vector finite element method with pe...A novel single-mode single-polarization （SMSP） photonic crystal fibre has been proposed and analysed based on the polarization-dependent coupling and absorption effect via a full-vector finite element method with perfectly matched layers. The numerical results predict that very efficient SMSP operation can be achieved with both high bandwidth and high extinction ratio at low loss penalty. Effects of the fibre structural parameters on the SMSP bandwidth and extinction ratio have been explored, which will provide useful guide for the design and fabrication of the fibre. The results obtained will be instructive for the realization of new SMSP fibres with high performance.展开更多
文摘频谱弥散(SMSP)干扰是一种针对线性调频(LFM)信号的相参压制干扰。根据SMSP干扰子脉冲的周期特性,提出了一种基于干扰重构和峭度最大化的干扰抑制方法。首先,利用自相关方法估计干扰子脉冲的周期,并根据干扰的产生原理确定子脉冲调频斜率,即可重构相位未知的干扰子脉冲;其次,对重构的干扰子脉冲分别设定不同的相位,并与接收信号做共轭相乘,根据相乘的结果确定干扰信号的初相位;最后,利用峭度最大化原理,确定干扰抑制因子,实现干扰抑制。仿真结果表明,本文方法能够有效实现干扰抑制,经过干扰抑制后的信干比可达20 d B以上,并且在存在噪声和相位误差的情况下,仍能够保持较高的信干噪比增益。
基金Project supported by the National Natural Science Foundation of China （Grant Nos 60372100 and 60507007）, and the State Key Development Program for Basic Research of China （Grant No 2003CB314906）.Acknowledgment The first author Liu Xiao-Yi would like to thank professor Yu Chong-Xiu for her constant encouragement and kind support.
文摘A novel single-mode single-polarization （SMSP） photonic crystal fibre has been proposed and analysed based on the polarization-dependent coupling and absorption effect via a full-vector finite element method with perfectly matched layers. The numerical results predict that very efficient SMSP operation can be achieved with both high bandwidth and high extinction ratio at low loss penalty. Effects of the fibre structural parameters on the SMSP bandwidth and extinction ratio have been explored, which will provide useful guide for the design and fabrication of the fibre. The results obtained will be instructive for the realization of new SMSP fibres with high performance.
