非圆信号与圆信号混合入射的DOA估计算法

利用非圆信号的非圆特性可以提高波达方向估计算法的性能，然而现有算法大多不适用于非圆信号与圆信号混合入射这样具有一般性的情况。通过分析混合入射信号的导引矢量所需要满足的约束条件，指出现有算法在信源数较多或低信噪比及低快拍数时会产生伪峰这一现象, 并分析产生原因，同时给出一种改进的方法。通过仿真可以看出，改进算法在保证可以同时估计所有信号波达角的基础上，还可以较好地抑制伪峰的产生，并且相对于传统算法提高了精度。

DOA estimation in solving mixed circular and non-circular incident signals

The nature of signals with a non-circularity rate can improve the performance of direction of arrival(DOA) estimation.However,most existing algorithms are not suitable for the general case in which both circular and non-circular incident signals exist.By analyzing the necessary conditions of steering vectors of mixed incident signals,the conclusion is drawn that pseudo peaks exist in the case of more sources,low signal to noise rate or small number of snapshots.Then,an improved algorithm is proposed.Simulation results show that all the DOAs of signals can be estimated by the proposed algorithm,and pseudo peaks are restrained.Besides,the accuracy is raised compared with the original algorithm.