一种新的基于稀疏表示的宽带信号DOA估计方法

摘要

该文提出一种基于稀疏表示的宽带信号波达方向(DOA)估计方法,解决稀疏表示方法在宽带信号DOA估计中由于基矩阵维数过大而使算法存储量和重构计算量大的问题.用单一频点的基矩阵代替频率和角度联合构建的基矩阵,使基矩阵的列数仅相当于一个频点处冗余基矩阵的列数,大大降低了稀疏重构方法的存储量和计算量.该方法首先对各频点的频域数据进行聚焦处理,将不同频率的数据堆叠到参考频率上并建立参考频率处的基矩阵,然后建立聚焦后的稀疏表示模型进行DOA估计,并采用奇异值分解进一步降低算法的运算量,最后给出残差门限的选择方法.该算法不仅适用于非相关信号,也可直接处理相关信号而不需要任何的去相关运算,且具有高的检测概率和估计精度,仿真实验和分析验证了该方法的有效性.%A novel wideband signals Direction-Of-Arrival (DOA) estimation method based on sparse representation is proposed. This algorithm can reduce the storage and calculation of the traditional sparse representation methods in wideband signals process, which is caused by the large dimension of base matrix. The over-complete dictionary is constructed by using one-frequency to replace the 2D combination of frequency and angle. The column number of constructed dictionary only equals to that of single-frequency redundant dictionary. The proposed method first adopts focused thought to stack the different frequency data to the reference frequency and founds the redundant dictionary with a single frequency. Then, a sparse recovery model is established to obtain the DOA estimations, which are coming from following the focus process. At the same time, the Singular Value Decomposition (SVD) is used to summarize each frequency to reduce computation burden further. Finally, an automatic selection criterion for the regularization parameter involved in the proposed approach is introduced. The proposed algorithm can effectively distinguish the correlative signals without any decorrelation processing, and it has higher accuracy and detection possibility. The experiment results indicate that the proposed method is effective to estimate the DOA of wideband signals.