信号个数估计和波束形成技术研究

【作者】 邹洲；

【导师】 张扬；

【作者基本信息】 电子科技大学 ， 信号与信息处理， 2007， 硕士

【摘要】 信号个数估计和波束形成是阵列信号处理领域里的核心问题,它们在雷达、声纳、生物医学、地震信号处理等方面有着极其广泛的应用。本文系统地研究了基于均匀圆阵的信号个数估计和波束形成方法,目的是对侦察接收机接收到的混合信号进行分离。本文主要的工作和成果如下:1.在均匀圆阵背景下,通过仿真分析了AIC、MDL准则和基于盖氏圆盘(GDE法)的信号个数估计方法的性能。并针对实际环境中存在相干干扰的情况,研究改进了一种基于移位元平滑的相干信号个数估计方法。2.研究了CAPON波束形成算法在均匀圆阵中的应用。引入了评价波束形成效果的重要参数,并在定向和全向均匀圆阵环境下,对频谱重叠信号的波束形成效果进行了分析。最后研究改进了一种相干波束形成方法,结合阵列内插思想对阵列进行虚拟平移,实现了对信号的解相干。3.分别在L阵、十字阵和均匀圆阵背景下,比较了这三种阵列在信号分离方面应用的优劣,指出均匀圆阵的应用性能优于其余两种阵列。4.介绍了相干处理(CSM)和非相干处理(ISM)的原理,并研究了基于子带平均的宽带信号个数估计方法和基于聚焦矩阵的宽带波束形成方法。本文对信号个数估计和波束形成方法在均匀圆阵中的应用性能做了详细研究,并在前人方法的基础上,改进出了针对相干信号的个数估计与波束形成方法。最后,总结了本文的工作,并展望下一步的研究。更多还原

【Abstract】 DETECTION OF THE SIGNAL NUMBER AND BEAMFORMING ARE THE IMPORTANT ISSUE OF ARRAY SIGNAL PROCESSING.IT HAS WIDELY APPLICATIONS IN RADAR,SONAR, OSCILLATION MEASUREMENT,BIOMEDICINE,SEISMIC SIGNAL PROCESING AND ETC.THIS THESIS THOROUGHLY STUDIES THESE TWO ASPECTS BASED ON UNIFORM CIRCULAR ARRAY,IN ORDER TO SEPARATE THE SIGNAL.MAIN WORKS ARE AS FOLLOWS:1.Based on uniform circular array mode,the performance of three estimation of the signal number algorithms is analyzed by computer simulations.But in practice,coherent interference can arise when multipath propagation or“smart”jammers is present, a new method is proposed in order to estimate the number of coherent signals.2.Performance of Capon beamforming based on uniform circular array is studied.Several important evaluating indexes of beamforming are introduced,and the effectiveness of spectrum overlaping signal is studied. based on directional antenna and omnidirectional antenna.Finally a new method is presented in order to solve coherent beamforming, the real array can be virtual shifted utilizing the interpolate method,and the decorrelation signal will be abtained.3.Based on L array、cross array and uniform circular array mode,the performance of this three arrays is compared.4. The principle of CSM and ISM method is introduced,and based on ISM method and wideband focusing matrix,methods of beamforming and detection of the number of wideband signal are studied.Finally,an overview of author’s work and the prospect of this article’s research are presented.更多还原