针对短时小样本条件下相干信号的波达方向(Direction Of Arrival, DOA)估计问题，该文提出了一种基于相干积累矩阵重构的快速解相干方法。首先利用相干积累技术对阵列接收快拍进行处理，得到累积快拍矢量，提高了数据信噪比。再依据累积快拍矢量的结构特点构造一个非降维等效协方差矩阵，理论分析可知，该矩阵的秩仅与信源个数相等，与信号间相关性无关，即实现了相干信源完全解相干。相较于空间平滑类算法，该方法避免了阵列孔径损失，估计精度高、计算量小。仿真结果验证了算法的有效性。
Based on coherent accumulation matrix reconstruction, a novel Direction Of Arrival (DOA) estimation decorrelation method of coherent signals is proposed using a small sample. First, the Signal to Noise Ratio (SNR) is improved by performing coherent accumulation operation on an array of observed data. Then, according to the structure characteristics of the accumulated snapshot vector, the equivalent covariance matrix, whose rank is the same as the number of array elements, is constructed. The rank of this matrix is proved to be determined just by the number of incident signals, which realize the decorrelation of coherent signals. Compared with spatial smoothing method, the proposed method performs better by effectively avoiding aperture loss with high-resolution characteristics and low computational complexity. Simulation results demonstrate the efficiency of the proposed method.
李 磊, 李国林, 刘润杰. 基于相干积累矩阵重构的波达方向估计新方法[J]. 雷达学报, 2015, 4(2): 178-184.
Li Lei, Li Guo-lin, Liu Run-jie. Novel Direction Of Arrival Estimation Method Based on Coherent Accumulation Matrix Reconstruction. JOURNAL OF RADARS, 2015, 4(2): 178-184.
Zheng Z, Li G J, and Teng Y L. Simplified estimation of 2D DOA for coherently distributed sources[J]. Wireless Peronal Communications, 2012, 62(4): 907-922.
[2]
Kassis C E, Picheral J, and Mokbel C. Advantages of nonuniform arrays using root-MUSIC[J]. Signal Processing, 2010, 90(2): 689-695.
[3]
蒋柏峰, 吕晓德, 向茂生. 基于广义MUSIC 算法的低仰角估 计新方法[J]. 雷达学报, 2013, 2(4): 422-429. Jiang Bai-feng, Lü Xiao-de, and Xiang Mao-sheng. A new low-elevation estimation method based on a general MUSIC algorithm[J]. Journal of Radars, 2013, 2(4): 422-429.
[4]
Pillai S U and Kwon B H. Forward-backward spatial smoothing techniques for coherent signal identification[J]. IEEE Transactions on Acoustics, Speech and Signal Processing, 1989, 37(1): 8-15．
[5]
Williams R T, Prasad S, Mahalanabis A K, et al.. An improved spatial smoothing technique for bearing estimation in a multi path environment[J]. IEEE Transactions on Acoustics, Speech and Signal Processing, 1988, 36(4): 425-432.
[6]
Gu J F, Wei P, and Tai H M, 2-D direction-of-arrival estimation of coherent signals using cross-correlation matrix[J]. Signal Processing, 2008, 88(1): 75-85.
[7]
高书彦, 陈辉, 王永良, 等. 基于均匀圆阵的模式空间矩阵重 构算法[J]. 电子与信息学报, 2007, 29(12): 2832-2835. Gao Shu-yan, Chen Hui, Wang Yong-liang, et al.. The MODE-TOEP algorithm based on uniform circular array[J]. Journal of Electronics & Information Technology, 2007, 29(12): 2832-2835.
[8]
Kareem A J, Hyuck M K, and Nizar T. Modified UCA-ESPRIT for estimating DOA of coherent signals using one snapshot[C]. Proceedings of the Vehicular Technology Conference, Singapore, 2008: 126-131.
[9]
谢菊兰, 李会勇, 何子述. 均匀圆阵相干信源DOA 估计的差 分算法[J]. 电子科技大学学报, 2012, 41(4): 516-521. Xie Ju-lan, Li Hui-yong, and He Zi-shu. DOA estimation of coherent sources using difference algorithm with the uniform circular arrays[J]. Journal of University of Electronic Science and Technology of China, 2012, 41(4): 516-521.
[10]
袁晓东, 万建伟, 程翥, 等. 基于直接数据域自适应算法的相干 信号DOA 估计[J]. 国防科技大学学报, 2012, 34(3): 131-135. Yuan Xiao-dong, Wan Jian-wei, Cheng Zhe, et al.. DOA estimation of correlated signals based on the adaptive algorithm in direct data domain[J]. Journal of National University of Defense Technology, 2012, 34(3): 131-135.
[11]
周围, 朱联祥, 周正中, 等. 相干多径环境下信号空间特征及 波达方向估计[J]. 电波科学学报, 2007, 22(4): 685-691. Zhou Wei, Zhu Lian-xiang, Zhou Zheng-zhong, et al.. Estimation of spatial signature and direction of arrivals for signals in coherent multipath environment[J]. Chinese Journal of Radio Science, 2007, 22(4): 685-691.
[12]
景小荣, 隋伟伟, 周围. 基于四阶累积量和时间平滑的相干信 号DOA 估计[J]. 系统工程与电子技术, 2012, 34(4): 789-795. Jing Xiao-rong, Sui Wei-wei, and Zhou Wei. DOA estimation of coherent signals based on fourth-order cumulant and temporal smoothing[J]. Systems Engineering and Electronics, 2012, 34(4): 789-795.
[13]
王凌, 李国林, 孟晶, 等. 用一次快拍数据实现二维完全解相 干和解互耦[J]. 系统工程与电子技术, 2012, 34(11): 2208-2214. Wang Ling, Li Guo-Lin, Meng Jing, et al.. Two-dimensional decorrelation and decoupling using single snapshot[J]. Systems Engineering and Electronics, 2012, 34(11): 2208-2214.
[14]
王凌, 李国林, 谢鑫. 互耦效应下用单快拍数据实现相干信源 完全解相干和解耦合[J]. 电子与信息学报, 2012, 34(10): 2532-2536. Wang Ling, Li Guo-lin, and Xie Xin. Decorrelation and decoupling of coherent signals in the presence of mutual coupling using single snapshot[J]. Journal of Electronics & Information Technology, 2012, 34(10): 2532-2536.
[15]
李涛, 李国林, 徐珩, 等. 采用相干积累矢量平滑实现小样本 信号解相干[J]. 西安电子科技大学学报, 2011, 38(6): 113-116. Li Tao, Li Guo-lin, Xu Heng, et al.. Small sample signals’ decorrelation using the coherent accumulation vector’ spatial smoothing[J]. Journal of Xidian University, 2011, 38(6): 113-116.
2015, Vol. 4 
