针对传统算法在低信噪比、小快拍、信源相干等情况下,波达方向 (Directional of Arrival,DOA)估计精度低的问题,提出了一种基于正交三角分解(Orthogonal Triangular Decomposition,QR)的正则化回溯匹配追踪算法(QR-Regularized Backtracking Matching Pursuit,QR-RBMP)。该算法首先对感知矩阵进行QR分解,以增大感知矩阵的独立性;再利用正则化思想和回溯机制优化匹配追踪算法,来提高信号重构精度;正则化思想对匹配追踪算法初次选择的原子进行二次筛选,选出最相关且能量最大的相关原子,回溯思想对正则化选择得到的原子进行再次筛选,删除不正确的原子,提高所选择原子的正确性,进而提高了匹配追踪算法的重构精度。最后得到重构的信号,信号非零元素所对应的位置即为DOA估计的结果。通过一系列仿真实验,并与多重信号分类算法(Multiple Signal Classification,MUSIC)、正则化正交匹配追踪算法(Regularized Orthogonal Matching Pursuit,ROMP)、基于子空间追踪算法(Subspace Tracking Algorithm,SP)、无平方根方法的SP算法(ISP)以及能量排序的回溯正则化匹配追踪算法(Backtracking Regularization Matching Pursuit for Energy Sorting,ESBRMP)估计方法基于均方根误差(Root Mean Square Error,RMSE)、分辨概率(Probability of Resolution,POR)进行对比分析。结果表明该算法在相同条件下均方根误差比现有最优方法降低了约42%,成功分辨率提高了8%。
A matching pursuit algorithm for regularization backtracking based on QR decomposition (QR-RBMP) is proposed in this paper to solve the problems of low precision of directional of arrival (DOA) estimation in the cases of low signal noise ratio (SNR), small snapshot and coherent signals. Firstly, the algorithm is performed on sensing matrix by QR decomposition to increase the independence of the sensing matrix. Then, the regularization idea and backtracking mechanism are used to optimize matching pursuit algorithm to improve the signal reconstruction precision. The regularization idea carries out secondary screening on the atoms initially selected by the matching tracking algorithm, and selects the most relevant atoms with the largest energy. The backtracking idea carries out secondary screening on the atoms selected by the regularization, deletes the incorrect atoms, improves the correctness of the selected atoms, and thus improves the reconstruction accuracy of the matching tracking algorithm. Finally, we obtain the reconstructed signal. The position of the non-zero element of the signal is the result of DOA estimation. Through a series of simulation experiments, the proposed algorithm is compared with MUSIC algorithm, regularized orthogonal matching pursuit algorithm (ROMP), subspace tracking algorithm, SP algorithm without Square Root (ISP) and energy sorting based backtracking regularized matching pursuit algorithm (ESBRMP) based on RMSE and POR. The results show that the proposed algorithm reduces the RMSE by 42% and improves the POR by 8% compared with the existing optimal methods under the same conditions.