基于冗余字典稀疏表示的二维DOA估计

针对互成一定角度的双线阵列,提出基于空间合成角冗余字典稀疏表示的二维波达方向估计新方法.将方位角和俯仰角余弦乘积用空间合成角代替,通过空间合成角构造冗余字典降低字典维数和长度,并将子阵接收数据矢量转化为稀疏表示问题,进而利用改进正交匹配追踪算法稀疏求解空间合成角,解算出方位角和俯仰角.与传统高分辨空间谱估计算法相比,无需特征分解和多维谱峰搜索,能在低信噪比、单快拍条件下精确估计相关或非相干信源空间角度,且需要子阵阵元数目较少.

Two dimensional DOA estimation based on redundant representation and sparse decomposition

For two uniform linear arrays with a certain included angle,a new Direction Of Arrival(DOA)estimation method based on sparse representation is proposed.By defining a space combined angle consisted of azimuth and elevation angles,the dimensions and length of the redundant dictionaries are largely reduced.The work of direction finding is transformed into a sparse representation problem of received data vectors,which is solved by an improved Orthogonal Matching Pursuit(OMP)algorithm.Compared with traditional high-resolution DOA methods,the new algorithm can achieve much better performance under condition of lower Signal-to-Noise Ratio(SNR),single snapshot of data,near and coherent sources,and it needs no eigenvalue decomposition and multi-dimensional spectrum searching,and needs fewer arrays.