基于空频域稀疏表示的宽频段DOA估计

Broadband DOA Estimation Based on Sparse Representation in Spatial Frequency Domain

该文提出一种基于空频域稀疏表示的宽频段波达方向(DOA)估计方法,解决稀疏表示方法在宽带接收机对窄带信号的频率和角度估计中的难题。用空间频率代替频率和方位角的2维组合构建过完备字典,字典的长度仅相当于窄带信号DOA估计的字典长度,却能覆盖整个无模糊频段,大大降低了稀疏分解的计算量。该方法首先在频域估计信号的准确频率,根据频域峰值的位置构建频域峰值协方差矩阵。对频域峰值协方差矩阵进行特征分解,利用主特征向量建立稀疏模型估计信号的DOA。算法在低信噪比下具有较高的估计精度,仿真实验和分析验证了该文方法的正确性和有效性。

A novel wide-band Direction-Of-Arrival（DOA） estimation method based on space-frequency sparse representation is proposed to estimate the frequency and DOA of narrow band signal with a wide band receiver.The over-complete dictionary is constructed by using space-frequency to replace the 2D combination of frequency and azimuth.Although the length of constructed dictionary equates to the length of narrow signal DOA estimation＇s dictionary,it could cover the whole unambiguous frequency.The precise frequency of signal is estimated through frequency spectral searching,and the frequency covariance matrix is constructed based on the position of frequency spectral peak.Then DOA can be obtained using the sparse representation of the large eigenvectors,which are coming form the frequency peak covariance matrix＇s Eigenvalue Decomposition（ED）.The proposed method has a higher precision in the low Signal to Noise Ratio（SNR）,and the number estimated can be much more than the array numbers.The experiment results indicate that the proposed method is correct and effective to estimate the frequency and DOA of narrow signal for wide-band receiver.