基于二次虚拟扩展的高分辨率波达方向估计方法

High resolution approach of direction-of-arrival estimation based on twice virtual extension

为进一步提高天线阵波达方向估计的分辨率,在四阶量多重信号分类方法的基础上,提出一种高分辨率的波达方向估计方法.利用阵列接收数据的四阶矩量进行虚拟阵列扩展,再利用阵列接收数据的共轭进行虚拟阵列扩展,实现二次虚拟扩展;将扩展后的阵列导向矢量和协方差矩阵用于波达方向估计,与原阵列导向矢量和协方差矩阵相比,相当于构造了更多的虚拟阵元,并扩展了阵列的孔径.仿真结果表明:与四阶量多重信号分类等波达方向估计方法相比,所提出的方法在波达方向估计中成功概率更高,均方误差更低,具有更高的分辨率.所提方法通过二次虚拟扩展,构造了更多的虚拟阵元,有效地提高了天线阵波达方向估计的分辨率.

In order to further improve the resolution of direction-of-arrival（ DOA） estimation of antenna array,a high resolution approach of DOA estimation is proposed based on the fourth-order multiple signal classification（ FOMUSIC） approach. First,the antenna array is extended through the fourth-order moment of the received data.Then,the antenna array is extended through the conjugate value of the received data. When the expanded steering vector and the expanded covariance matrix are used for DOA estimation instead of the original steering vector and the original covariance matrix,virtual array elements are formed and the aperture of array is extended. It is shown by simulation results that,compared to the FO-MUSIC approach,the proposed method has a higher probability of target resolution,lower root mean square error and higher resolution. Hence,more virtual array elements are formed by the proposed approach based on twice virtual extension,and the resolution of DOA estimation of antenna array is effectively improved.