宽带信号DOA估计方法研究

发布时间：2019-04-10 16:23

【摘要】：波达角估计(Direction of Arrival,DOA)是信号处理领域一个非常重要的问题,涉及雷达、声纳、无线通信等方面,在军事和民用领域有广泛应用。其中,相比窄带信号,宽带信号具有信息量大、抗干扰能力强、混淆背景相关性小、分辨能力强等优点,因此对于宽带信号DOA估计算法的研究意义重大。本论文主要研究工作包括:首先讨论了简化的阵列及信号模型、宽带信号定义及数学模型、DOA估计的重要影响因素和算法的性能指标。其次对比研究了基于信号子空间融合的宽带DOA估计方法,包括非相干信号子空间(ISSM)算法和相干信号子空间(CSSM)算法,具体描述了CSSM算法中几种聚焦变换矩阵的构造原理,利用计算机仿真实验对这几种聚焦矩阵构造方法的性能进行对比分析。最后研究基于稀疏信号表示的宽带方位估计算法,包括l1-SVD算法和联合l0范数的JLZA算法。l1-SVD不能联合运用所有子带的信息估计信号来波方向,而JLZA只是联合利用信号能量,且参数需要人为设定。因此研究了能解决上述问题的子带信息融合(SIF)DOA估计算法。针对SIF算法存在的运算量大、信号幅度估计不准等问题,提出了基于孔径扩展的SIF算法,提高了信号能量估计精度和信源估计数目,降低了运算量,并且在低信噪比条件下仍能够保持估计精度,利用仿真实验验证上述结论。
[Abstract]:Angle of arrival estimation (Direction of Arrival,DOA) is a very important problem in the field of signal processing, which involves radar, sonar, wireless communication and so on. It is widely used in military and civilian fields. Compared with narrow-band signal, broadband signal has many advantages, such as large amount of information, strong anti-jamming ability, small correlation of confused background, strong resolution and so on. Therefore, the research on DOA estimation algorithm of wideband signal is of great significance. The main work of this thesis is as follows: firstly, the simplified array and signal model, the definition and mathematical model of wideband signal, the important influencing factors of DOA estimation and the performance index of the algorithm are discussed. Secondly, the wideband DOA estimation methods based on signal subspace fusion are compared, including non-coherent signal subspace (ISSM) algorithm and coherent signal subspace (CSSM) algorithm, and the construction principles of several focused transform matrices in CSSM algorithm are described in detail. Computer simulation experiments are used to compare and analyze the performance of these methods. Finally, the wideband DOA estimation algorithm based on sparse signal representation is studied, including the l1-SVD algorithm and the JLZA algorithm combined with the l0 norm. L1-SVD can not jointly estimate the direction of the signal by using the information of all sub-bands. And JLZA is only a combination of signal energy, and the parameters need to be set artificially. Therefore, the sub-band information fusion (SIF) DOA estimation algorithm which can solve the above problems is studied. In order to solve the problems of SIF algorithm, such as large computational complexity and inaccuracy of signal amplitude estimation, a new SIF algorithm based on aperture expansion is proposed, which improves the accuracy of signal energy estimation and the number of source estimates, and reduces the computational complexity. Under the condition of low signal-to-noise ratio (SNR), the estimation accuracy can still be maintained, and the above conclusions are verified by simulation experiments.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN911.23

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