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对光OFDM系统中的三种同步算法进行了理论分析,基于仿真实验,针对定时度量、定时偏差、丢帧率三个性能参数进行了对比分析。仿真分析表明T.Schmidl&D.Cox算法由于循环前缀(Cyclic Prefix,CP)缘故使得其定位精确性欠佳,偏差较大,无法进行精确定位,但算法稳定性及丢帧率方面具有很好的性能。而H.Minn和Li-xun Huang&Li-jun Sun两种同步算法定位精确性相对较好,偏差较小,但在稳定性及丢帧率方面,后者优于前者。因而在这三种同步算法中,Li-xun Huang&Li-jun Sun算法性能较好,适应性较强,更具实际应用价值。 相似文献
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对于均匀线性天线阵列近场目标定位研究是探测领域重要难点之一。本文根据前期近场基于差分迭代传播计算模型研究基础,提出一种新型高精度近场无源定位算法,针对均匀线性阵列近场目标空间几何结构,突破传统菲涅尔近似近场传播模型的束缚,建立全新高精度目标关系模型并形成定位解析表达式,通过阵列处理估计改进到达时差(TOA)定位观测量,利用新算法快速准确地获取近场多个独立同分布目标的定位信息。仿真实验结果表明:新算法机理不同于传统近场估计分析,特别是定位解析式的引入使得位置精度提升的同时计算量大为降低,更好地适应了近场非线性关系结构,性能分析显示TOA误差对定位估计精度的影响较为有限,在典型信噪比条件下新算法的距离和角度估计精度优于几种常规处理算法,未来具有深入研究的价值。 相似文献
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激光多普勒测速雷达高精度频率估计综合算法 总被引:1,自引:0,他引:1
为实现对目标速度的高精度测量,该文搭建了激光多普勒测速雷达系统,并对其频率估计算法进行了研究。对基于自相关运算的频率估计算法进行了改进,使其性能达到了最优,并结合Quinn算法的特点,提出了一种对信噪比具备自适应性的频率估计综合算法。Monte Carlo模拟仿真和圆形转台测速实验结果表明:新算法具有更优的性能,且采用该算法后,系统速度的均方根误差小于2 mm/s,相对误差优于0.06 %,实验结果与理论分析和仿真结果一致。 相似文献
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研究了定位观测方程的解析求解方法,利用所得方法,在给定目标星座条件下,对定位观测方程的求解进行了仿真。结果表明:解析方法不能直接应用于定位观测方程的求解中,但将解析方法和数值方法相结合,可显著改善求解性能。 相似文献
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针对无源定位必须实现快速和稳定定位跟踪的要求,在传统定位方法基础上引入角度变化率和多普勒频率变化率信息;在此基础上提出了一种基于空频域信息的简化不敏卡尔曼滤波(UKF)算法并对其定位性能进行分析;仿真结果表明简化的UKF算法在大大降低运算量(和EKF算法相当)的同时能保持和标准UKF算法同样的定位性能并且要明显优于EKF算法;增加高精度的角度变化率和多普勒频率变化率信息能够显著改善定位性能. 相似文献
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首先对海上运动平台多站时差定位系统中几种典型定位算法进行了理论分析,然后讨论了双曲直接解法、Chan算法和近似极大似然定位算法对系统定时误差和站位误差的影响。在仿真分析下进行了定位性能分析。最终结合海面上的复杂环境背景,选择Chan算法来进行定位解算。 相似文献
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该文针对北斗卫星定位系统和惯性导航系统提出组合导航卡尔曼滤波定位算法,对组合导航滤波算法的可控性、可观性进行了分析,并用数值分析方法从可观性定义出发分析了各个状态的可观测度,从稳定性的定义出发分析了组合算法的稳定性和渐进稳定性.由于双星时不能对钟差滤波,所以对滤波定位观测模型进行了改进,引入伪距率和惯性器件输出的加速度作为观测量.仿真表明改进方案大大提高了组合定位系统的工作稳定性,抗突发性误差的能力提高了一个数量级,而且双星的情况下可以对钟差滤波. 相似文献
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研究了定位观测方程的解析求解方法,利用所得方法,在给定目标星座条件下,对定位观测方程的求解进行了仿真。结果表明:解析方法不能直接应用于定位观测方程的求解中,但将解析方法和数值方法相结合,可显著改善求解性能。 相似文献
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针对传统的三星时差无源定位算法不能求解辐射源高程这一问题,提出了以高精度测向作为辅助对辐射源进行定位的算法。从该算法的定位原理入手,建立了其定位模型并分析了其定位误差;同时提出采用UKF算法对多次测量的结果进行处理以提高定位的精度;最后对该算法进行了计算机仿真。研究表明,该算法不需要进行高程假设即可实现对辐射源的快速高精度无源定位。 相似文献
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Genetic Algorithm in Reduction of Numerical Dispersion of 3-D Alternating-Direction-Implicit Finite-Difference Time-Domain Method 总被引:2,自引:0,他引:2
A new method to reduce the numerical dispersion of the 3-D alternating-direction-implicit finite-difference time-domain method is proposed. Firstly, the numerical formulations are modified with the artificial anisotropy, and the new numerical dispersion relation is derived analytically. Moreover, theoretical proof of the unconditional stability is shown. Secondly, the relative permittivity tensor of the artificial anisotropy can be obtained by the adaptive genetic algorithm. In order to demonstrate the accuracy and efficiency of this new method, several examples are simulated. The numerical results and the computational requirements of the proposed method are then compared with those of the conventional method and measured data. In addition, the reduction of the numerical dispersion is investigated as the objective function of the genetic algorithm. It is found that this new method is accurate and efficient by choosing a proper objective function 相似文献
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《Microwave Theory and Techniques》2006,54(10):3739-3745
An efficient and rigorous numerical method, based on the spatial-domain method of moments (MoM) in conjunction with the closed-form Green's functions, is devised for the analysis of multiple vertical conductors in printed circuits. As this combination has already proven to be very efficient for the analysis of printed structures with horizontal and vertical conductors, it is extended to efficiently handle multiple vertical conductors. Some circuits with multiple vertical strips are analyzed using the proposed method, and results are compared either to those presented in the literature or to those obtained from the commercial software em by SONNET Software, North Syracuse, NY. Computational efficiency of the algorithm is assessed in terms of CPU time, and it is observed that the computational cost of the proposed algorithm is an order of magnitude less than that of the straightforward implementation of the underlaying method of the algorithm—the spatial-domain MOM using closed-form Green's functions. 相似文献
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An Approximately Efficient TDOA Localization Algorithm in Closed-Form for Locating Multiple Disjoint Sources With Erroneous Sensor Positions 总被引:1,自引:0,他引:1
《Signal Processing, IEEE Transactions on》2009,57(12):4598-4615
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Based on numerical results obtained from solutions to integral equations, other numerical results and theoretical considerations, a set of closed-form formulas is presented for approximate calculation of frequency-dependent resistance and inductance per unit length of microstrip and strip transmission lines. Extensive verifications reveal that the accuracy obtained by these closed-form formulas is better than 10% for a wide range of parameters 相似文献
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Exact and numerically stable closed-form expressions for potential coefficients of rectangular conductors 总被引:1,自引:0,他引:1
Jain J. Cheng-Kok Koh Balakrishnan V. 《Circuits and Systems II: Express Briefs, IEEE Transactions on》2006,53(6):458-462
Existing exact closed-form expressions for the scalar mutual and self-potential coefficients for rectangular conductors may be ill-conditioned for certain geometries. We propose new, exact, closed-form expressions for potential coefficients that are much better-conditioned. The basic idea is to express all potential coefficients as weighted sums of mutual and self-potential coefficients of suitably defined virtual plates. Experimental results are presented to demonstrate the improved numerical stability of the new formulas. 相似文献
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提出了一种基于空间滤波(Spatial Filtering-Finite-Difference Time-Domain,SF-FDTD)算法的亚网格技术,使得FDTD算法的Courant-Friedrich-Levy(CFL)稳定性条件可通过空间频域滤波操作得以提高,从而获得高稳定度FDTD算法.进一步将SF-FDTD算法应用到亚网格技术中,可使亚网格区域时间步长的选取取与粗网格一致,从而极大地提高了计算效率.数值计算结果表明,在求解带有精细结构的电磁问题上,所提算法具有较高的准确性和有效性. 相似文献
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