基于互相关矢量重构的解相干实值Root-MUSIC算法*

实值Root-MUSIC算法是一种计算量小、精度高的波达方向估计算法，但其最多能处理两个相干信源，阵元利用率很低。为了解决此问题，提出了一种新的实值Root-MUSIC算法，利用阵列接收数据的互相关矢量重构相关矩阵，使其具有Toeplitz特性。新算法无须空间平滑，无阵列孔径损失,可估计的相干信源数更多。实验仿真表明，与原算法相比，新算法实现更简单、计算量更小、性能更好，对于八阵元的阵列，原算法只能分辨两个相干信源，新算法可以成功估计四个相干信源，为实值类算法在多径环境领域的DOA估计提供了一条新途径。

Root-MUSIC with real-valued eigen-decomposition for coherent signals based on cross-correlation vector reconstruction

Aiming at reducing administrative cost, this paper proposed an administrative hierarchical-user-based access control model: AHURBAC(administrative hierarchical-user RBAC). The AHURBAC model provided lower administration overhead by making users and administrators hierarchical. Presented a formal definition of AHURBAC and defined can_assign, can_revoke, can_assignp and can_revokep. The model does benefit to lowering effective the authorization administrative cost.