The phenomena of polarization rotation induced by self-modulation in semiconductor optical amplifier (SOA) are analyzed theoretically. The relationship between polarization parameters and gain as well as phase is obta...The phenomena of polarization rotation induced by self-modulation in semiconductor optical amplifier (SOA) are analyzed theoretically. The relationship between polarization parameters and gain as well as phase is obtained by the correlation parameter of ellipse polarization and SOA nonlinearity polarization rotation theory. The experiment employs polarizer drive by walking electromotor and power meter, the light power of 360 degree is measured. The transformation law of output polarization power components is found for obvious polarization rotation in the selected coordinate axes based on connection of polarization state in difference axes. Using this law make the manipulation easily on getting ideal polarization state. It can offer a fine method to realize all-optical switch and other logic elements in experiment. This work is of great significance for the applications of SOA nonlinear polarization rotation at high-speed all-optical signal processing and all-optical logic gate.展开更多
The existing research results show that a fixed single station must conduct three consecutive frequency shift measurements and obtain the target’s moving speed by constructing two frequency difference equations. This...The existing research results show that a fixed single station must conduct three consecutive frequency shift measurements and obtain the target’s moving speed by constructing two frequency difference equations. This article proposes a new method that requires only two consecutive measurements. While using the azimuth measurement to obtain the angular difference between two radial distances, it also conducts two consecutive Doppler frequency shift measurements at the same target azimuth. On the basis of this measurement, a frequency difference equation is first constructed and solved jointly with the Doppler frequency shift equation. By eliminating the velocity variable and using the measured angular difference to obtain the target’s lead angle, the target’s velocity can be solved by using the Doppler frequency shift equation again. The new method avoids the condition that the target must move equidistantly, which not only provides an achievable method for engineering applications but also lays a good foundation for further exploring the use of steady-state signals to achieve passive positioning.展开更多
针对大方位失准角捷联惯性导航系统误差模型非线性的特点,利用基于迭代测量更新的中心差分卡尔曼滤波(iterated central difference Kalman filter,ICDKF)方法进行初始对准。与传统的非线性扩展卡尔曼滤波相比,ICDKF不仅能够提高滤波精...针对大方位失准角捷联惯性导航系统误差模型非线性的特点,利用基于迭代测量更新的中心差分卡尔曼滤波(iterated central difference Kalman filter,ICDKF)方法进行初始对准。与传统的非线性扩展卡尔曼滤波相比,ICDKF不仅能够提高滤波精度,而且不需要模型的具体解析形式,避免了复杂的雅可比矩阵的推导;同时ICDKF通过迭代测量更新,提高了目前存在的中心差分卡尔曼滤波的估计精度。仿真结果进一步表明ICDKF算法的可行性与优越性,能够满足初始对准的要求。展开更多
为实现对静/动目标的有效定位,推导出定位精度的几何稀释(Geometric Dilution of Positioning Accuracy,GDOP)的协方差矩阵计算公式和GDOP的影响因素。利用时差和目标方位角对静/动目标进行定位的基本原理,可得到定位精度的一般表达式...为实现对静/动目标的有效定位,推导出定位精度的几何稀释(Geometric Dilution of Positioning Accuracy,GDOP)的协方差矩阵计算公式和GDOP的影响因素。利用时差和目标方位角对静/动目标进行定位的基本原理,可得到定位精度的一般表达式及其理论曲线,以及其目标和接收机之间的相对几何关系与测量误差的关系,可有效实现对静/动目标的定位。展开更多
为解决当前5G无线网络中高速移动节点信号定位不准确和高稳定分布噪声(high stable distribution noise,HSDN)等特殊偏移噪声降低定位准确性的问题,提出基于电控旋转序列位移接收结构的5G无线网络信号定位算法。利用单一节点接收结构及...为解决当前5G无线网络中高速移动节点信号定位不准确和高稳定分布噪声(high stable distribution noise,HSDN)等特殊偏移噪声降低定位准确性的问题,提出基于电控旋转序列位移接收结构的5G无线网络信号定位算法。利用单一节点接收结构及环接收结构并采取分层方式,构建电控旋转序列位移接收结构;基于待定位信号与中央基站及各层接收节点之间的切线关系,初步估计待测信号方位;针对信号发射环境中的HSDN噪声频率漂移特性,通过信号定位差分机制,联合最优极大似然估计,构建基于差分方式的方位角精度优化机制,降低定位误差。仿真结果表明,与采取单一节点接收方式的GDAM算法及采取单层环接收方式的NUPOS-1算法相比,在HSDN噪声干扰环境下,该算法具有更低的信号定位误差。展开更多
文摘The phenomena of polarization rotation induced by self-modulation in semiconductor optical amplifier (SOA) are analyzed theoretically. The relationship between polarization parameters and gain as well as phase is obtained by the correlation parameter of ellipse polarization and SOA nonlinearity polarization rotation theory. The experiment employs polarizer drive by walking electromotor and power meter, the light power of 360 degree is measured. The transformation law of output polarization power components is found for obvious polarization rotation in the selected coordinate axes based on connection of polarization state in difference axes. Using this law make the manipulation easily on getting ideal polarization state. It can offer a fine method to realize all-optical switch and other logic elements in experiment. This work is of great significance for the applications of SOA nonlinear polarization rotation at high-speed all-optical signal processing and all-optical logic gate.
文摘The existing research results show that a fixed single station must conduct three consecutive frequency shift measurements and obtain the target’s moving speed by constructing two frequency difference equations. This article proposes a new method that requires only two consecutive measurements. While using the azimuth measurement to obtain the angular difference between two radial distances, it also conducts two consecutive Doppler frequency shift measurements at the same target azimuth. On the basis of this measurement, a frequency difference equation is first constructed and solved jointly with the Doppler frequency shift equation. By eliminating the velocity variable and using the measured angular difference to obtain the target’s lead angle, the target’s velocity can be solved by using the Doppler frequency shift equation again. The new method avoids the condition that the target must move equidistantly, which not only provides an achievable method for engineering applications but also lays a good foundation for further exploring the use of steady-state signals to achieve passive positioning.
文摘针对大方位失准角捷联惯性导航系统误差模型非线性的特点,利用基于迭代测量更新的中心差分卡尔曼滤波(iterated central difference Kalman filter,ICDKF)方法进行初始对准。与传统的非线性扩展卡尔曼滤波相比,ICDKF不仅能够提高滤波精度,而且不需要模型的具体解析形式,避免了复杂的雅可比矩阵的推导;同时ICDKF通过迭代测量更新,提高了目前存在的中心差分卡尔曼滤波的估计精度。仿真结果进一步表明ICDKF算法的可行性与优越性,能够满足初始对准的要求。
文摘为实现对静/动目标的有效定位,推导出定位精度的几何稀释(Geometric Dilution of Positioning Accuracy,GDOP)的协方差矩阵计算公式和GDOP的影响因素。利用时差和目标方位角对静/动目标进行定位的基本原理,可得到定位精度的一般表达式及其理论曲线,以及其目标和接收机之间的相对几何关系与测量误差的关系,可有效实现对静/动目标的定位。
文摘为解决当前5G无线网络中高速移动节点信号定位不准确和高稳定分布噪声(high stable distribution noise,HSDN)等特殊偏移噪声降低定位准确性的问题,提出基于电控旋转序列位移接收结构的5G无线网络信号定位算法。利用单一节点接收结构及环接收结构并采取分层方式,构建电控旋转序列位移接收结构;基于待定位信号与中央基站及各层接收节点之间的切线关系,初步估计待测信号方位;针对信号发射环境中的HSDN噪声频率漂移特性,通过信号定位差分机制,联合最优极大似然估计,构建基于差分方式的方位角精度优化机制,降低定位误差。仿真结果表明,与采取单一节点接收方式的GDAM算法及采取单层环接收方式的NUPOS-1算法相比,在HSDN噪声干扰环境下,该算法具有更低的信号定位误差。
