MIMO雷达多目标角度估计的空间平滑改进算法

Angle Estimation Algorithm of MIMO Radar for Multiple Targets Based on Improved Spatial Smoothing

针对基于阵列协方差矩阵特征分解的子空间类算法存在的问题,提出了一种基于改进空间平滑的新方法。首先介绍了"等效信源"的概念,在此基础上分析了当目标数多于发射阵元数时,一些基于子空间类算法失效的原因;从理论上推导说明了在接收阵元数足够多的情况下,本文算法可突破发射阵元数对可估计目标数的限制的机理,从而使得MIMO雷达在发射阵元数较少时能估计更多的目标。仿真结果表明:本文所提方法具有比TDS算法更好的估计性能。

Subspace-based algorithms,which provide high spectrum resolution and is of less time-consuming,are the classical and commonly used methods.However,there are still problems when applying the algorithms to MIMO radar.To solve the problem of the DOA estimation of multiple targets for MIMO radar,a new method based on improved spatial smoothing is proposed.The concept of ＂equivalent sources＂ is introduced,based on it,the reason why several subspace-based algorithms would fail when the number of targets is more than the number of transmit antennas is analyzed.The mechanism of the proposed method to overcome the limitation of the number of transmit antennas in the condition of sufficient receive antennas is derived and expounded,which makes the MIMO radar estimate more targets in the case of fewer transmit antennas.The simulation results demonstrate that the proposed method has a better estimated performance than the TDS.