基于四元数的改进空间平滑解相干算法

An Improved Spatial Smoothing Algorithm Based on Quaternion

针对常规的四元数空间平滑算法解相干时没有充分利用各子阵的互相关信息导致信号波达方向估计分辨率较差的问题,提出了一种基于四元数的改进空间平滑解相干算法。首先,利用四元数的正交结构可以很好地保持极化敏感阵列各阵元两分量输出信号之间固有的正交特性,建立了四元数接收信号模型。然后,在常规的空间平滑算法的基础上推导了改进的空间平滑解相干算法。该算法利用了阵列各子阵接收信号的全部互相关和自相关信息,在信号波达方向相近和信噪比较低的情况下,具有比常规空间平滑算法更优的波达方向估计性能。最后,通过计算机仿真验证了改进算法的有效性。

The conventional quaternion spatial smoothing algorithm fails to make full use of the crosscorrelation information among the sub-arrays, thus it produces poor resolution when estimating the signal directions. An improved spatial smoothing algorithm based on quaternion is proposed in this paper. First, the quaternion signal model is given and the inherent orthogonal structure of each element has been kept well for polarization sensitive array. Second, the newly spatial smoothing algorithm is derived, and it makes full use of the cross-correlation and the auto-correlation information of all the sub-arrays. The proposed algorithm outperforms the conventional quaternion spatial smoothing algorithm when the incident signals have a close direction of arrival and a low signal to noise ratio. Finally, simulation results are shown to verify the efficacy of the improved algorithm.