To the problem of the unknown underwater target detection, according to the feature that the underwater target radiated noise contains the stable line spectrum, a weighted method based on the main-to-side lobe ratio ...To the problem of the unknown underwater target detection, according to the feature that the underwater target radiated noise contains the stable line spectrum, a weighted method based on the main-to-side lobe ratio （MSLR） is proposed for broadband beam-forming. This weighted method can be implemented by using the following steps. Firstly, optimize the spatial spectrum of each frequency unit by the second-order cone programming （SOCP）, and obtain the optimized spatial spectrum with lower side lobe. Secondly, construct weighting factors based on the MSLR of the optimized spatial spectrums to from weight factors. Lastly, cumulate the spatial spectrum of each frequency unit via the weight statistical method of this paper. This method can restrain the disturbance of background noise, enhance the output signal-to-noise ratio （SNR）, and overcome the difficulty of traditional four-dimensional display. The theoretical analysis and simulation results both verify that this method can well enhance the spatial spectrum of line spectrum units, restrain the spatial spectrum of background noise units, and improve the performance of the broadband beam-forming.展开更多
提出了一种基于量子粒子群算法(QPSO)的智能天线声阵列自适应波束形成算法模型,该模型应用QPSO对阵列天线半径和阵元初始相位进行调整,进而控制智能天线声阵列的波束形成,使天线波束主瓣对准期望声源信号方向,零陷对准干扰信号方向,并...提出了一种基于量子粒子群算法(QPSO)的智能天线声阵列自适应波束形成算法模型,该模型应用QPSO对阵列天线半径和阵元初始相位进行调整,进而控制智能天线声阵列的波束形成,使天线波束主瓣对准期望声源信号方向,零陷对准干扰信号方向,并形成最优的增益主瓣和旁瓣的峰峰比.Matlab仿真结果表明,该模型增强主瓣方向增益约10 d B,降低噪声方向增益约3.75 d B,有效提升了系统通信能力和抗干扰能力,并且在扫描角度上呈现普适性.展开更多
为了提高高轨电子侦察卫星对雷达信号的侦收灵敏度,增大截获概率,提出了一种基于天线波束偏转的雷达主瓣侦收方法。根据雷达辐射源最大仰角,高轨卫星可以获得雷达信号的主副瓣侦收区域。通过天线波束在短时间内进行特定方向和一定角度...为了提高高轨电子侦察卫星对雷达信号的侦收灵敏度,增大截获概率,提出了一种基于天线波束偏转的雷达主瓣侦收方法。根据雷达辐射源最大仰角,高轨卫星可以获得雷达信号的主副瓣侦收区域。通过天线波束在短时间内进行特定方向和一定角度的偏转,使指向雷达副瓣的天线波束实时对准雷达主瓣侦收区域,实现雷达主瓣侦收。仿真实验结果表明:取雷达主瓣最大仰角为40°、天线波束宽度为2°,通过天线波束偏转7.6°,可完成雷达辐射源主瓣侦收;与副瓣侦收相比,主瓣侦收信号信噪比至少可提高12.24 d B。展开更多
阵列雷达的主瓣干扰抑制是雷达抗干扰领域的一个难题。提出了一种基于子阵域的盲源分离主瓣抗干扰算法。该算法以特征矩阵近似联合对角化(joint approximate diagonalization of eigen-matrices,JADE)盲源分离算法为基础,与传统的全向...阵列雷达的主瓣干扰抑制是雷达抗干扰领域的一个难题。提出了一种基于子阵域的盲源分离主瓣抗干扰算法。该算法以特征矩阵近似联合对角化(joint approximate diagonalization of eigen-matrices,JADE)盲源分离算法为基础,与传统的全向阵列算法相比,该算法提供了较低的复杂度,尤其是针对大型阵列时,算法的优势更加显著。其设计思路是先将全向阵列划分到子阵域;然后在子阵域的基础上利用多重信号分类和恒虚警检测,设计了一种新的盲源分离信道数预估计方法,为JADE提供先验信息;最后设定盲源分离通道数,使接收信号分离,并将分离信号分别进行脉冲压缩、信号检测等步骤,从而达到雷达主瓣抗干扰的目的。通过仿真分析可知,该方法可以实现目标信号和干扰信号的有效分离,且计算量对比全向阵列有显著降低,具有一定的工程应用前景。展开更多
基金supported by the National Natural Science Foundation of China(Grant No.61372180)the National Key Scientific Instrument Equipment Development Project of China(Grant No.2013YQ140431)
文摘To the problem of the unknown underwater target detection, according to the feature that the underwater target radiated noise contains the stable line spectrum, a weighted method based on the main-to-side lobe ratio （MSLR） is proposed for broadband beam-forming. This weighted method can be implemented by using the following steps. Firstly, optimize the spatial spectrum of each frequency unit by the second-order cone programming （SOCP）, and obtain the optimized spatial spectrum with lower side lobe. Secondly, construct weighting factors based on the MSLR of the optimized spatial spectrums to from weight factors. Lastly, cumulate the spatial spectrum of each frequency unit via the weight statistical method of this paper. This method can restrain the disturbance of background noise, enhance the output signal-to-noise ratio （SNR）, and overcome the difficulty of traditional four-dimensional display. The theoretical analysis and simulation results both verify that this method can well enhance the spatial spectrum of line spectrum units, restrain the spatial spectrum of background noise units, and improve the performance of the broadband beam-forming.
文摘提出了一种基于量子粒子群算法(QPSO)的智能天线声阵列自适应波束形成算法模型,该模型应用QPSO对阵列天线半径和阵元初始相位进行调整,进而控制智能天线声阵列的波束形成,使天线波束主瓣对准期望声源信号方向,零陷对准干扰信号方向,并形成最优的增益主瓣和旁瓣的峰峰比.Matlab仿真结果表明,该模型增强主瓣方向增益约10 d B,降低噪声方向增益约3.75 d B,有效提升了系统通信能力和抗干扰能力,并且在扫描角度上呈现普适性.
文摘为了提高高轨电子侦察卫星对雷达信号的侦收灵敏度,增大截获概率,提出了一种基于天线波束偏转的雷达主瓣侦收方法。根据雷达辐射源最大仰角,高轨卫星可以获得雷达信号的主副瓣侦收区域。通过天线波束在短时间内进行特定方向和一定角度的偏转,使指向雷达副瓣的天线波束实时对准雷达主瓣侦收区域,实现雷达主瓣侦收。仿真实验结果表明:取雷达主瓣最大仰角为40°、天线波束宽度为2°,通过天线波束偏转7.6°,可完成雷达辐射源主瓣侦收;与副瓣侦收相比,主瓣侦收信号信噪比至少可提高12.24 d B。
文摘阵列雷达的主瓣干扰抑制是雷达抗干扰领域的一个难题。提出了一种基于子阵域的盲源分离主瓣抗干扰算法。该算法以特征矩阵近似联合对角化(joint approximate diagonalization of eigen-matrices,JADE)盲源分离算法为基础,与传统的全向阵列算法相比,该算法提供了较低的复杂度,尤其是针对大型阵列时,算法的优势更加显著。其设计思路是先将全向阵列划分到子阵域;然后在子阵域的基础上利用多重信号分类和恒虚警检测,设计了一种新的盲源分离信道数预估计方法,为JADE提供先验信息;最后设定盲源分离通道数,使接收信号分离,并将分离信号分别进行脉冲压缩、信号检测等步骤,从而达到雷达主瓣抗干扰的目的。通过仿真分析可知,该方法可以实现目标信号和干扰信号的有效分离,且计算量对比全向阵列有显著降低,具有一定的工程应用前景。
