复合高斯杂波中MIMO雷达DOA估计的克拉美-罗下限

Cramer-Rao Bounds of DOA Estimation for MIMO Radars in Compound-Gaussian Clutter

该文研究了复合高斯杂波下MIMO雷达DOA估计的平均克拉美-罗下限(Average CRB,ACRB)。首先,给出了MIMO雷达信号与杂波模型;然后,推导出目标DOA估计ACRB的一般关系式,在此基础上给出当杂波texture分量满足反Gamma分布时,ACRB的闭合表达式;接着,研究了目标DOA估计的中断CRB(Outage CRB),克服了一个发射单元时ACRB发散的问题;最后进行计算机仿真并给出结论。结果表明MIMO雷达的空间分集能有效地降低其DOA估计ACRB,且ACRB随发射单元数量的提高而减小;另外在相同条件下,MIMO雷达在复合高斯背景下DOA估计的ACRB大于相应高斯背景下的ACRB。

This paper studies the Average Cramer-Rao Bounds （ACRB） for estimating Direction Of Arrival （DOA） in compound-Gaussian clutter using Multi-Input Multi-Output （MIMO） radars. Firstly, the MIMO radar signal and compound-Gaussian clutter models are introduced. Secondly, the general ACRB expression is derived. Then, a closed-form ACRB is given for the inverse-Gamma distributed texture component. Thirdly, the Outage CRB is introduced as a supplement to the divergence of ACRB when there is only one transmit radar element. Finally, the DOA estimation performances of MIMO radars are simulated through computer simulations under different conditions. Theoretical analyses and computer simulations show that the spatial diversity of MIMO radar can improve the performance of DOA estimation effectively. The ACRB decreases as the number of the transmit radar elements increases. It is also found that the ACRB in compound-Gaussian clutter is inferior to that in Gaussian clutter. The research conducted in this paper reveals the fundamental performances of the MIMO radars.