Research On Angle Estimation Algorithms Based On Fourth-order Cumulants For MIMO Radar

Multiple input multiple output (MIMO) radar has many prominent advantages in better resolution and estimated precision of the targets, anti-interference technology and anti-stealth technology, which has been drawn considerable attention for numerous academicians all over the world. The angle estimation issue is an important content in the array signal processing for bistatic MIMO radar. Recently, Many angle estimation algorithms are studied in Gaussian white noise, while in Gaussian colored noise, the angle performance of them will be declined,sometimes the wrong estimation is come out. Therefore, in the Gaussian colored noise, this dissertation uses the blindness to Gaussian noise of the higher-order cumulants to solve the angle estimation issues in bistatic MIMO radar.At first, the signal model of bistatic MIMO radar is constructed. Then, the basic principle of angle estimation algorithms in bistatic MIMO radar are introduced detailedly.The simulation experiments are used to simulate and validate the conclusions. Finally, the basic academic knowledge of higher-order statistics are studied, which is laid the solid theoretical foundation for the further research on angle estimation.What's more, the MUSIC algorithm based on fourth-order cumulants is proposed, which solves the problem of the performance declining based on traditional second-order statistics in the circumstance of Gaussian colored noise. Through the theoretical analysis and simulation experiments, the proposed method is proved to be effective in prohibiting the effect of the Gaussian colored noise and can be used to estimate the angle parameters correctly. While this algorithm needs the two dimensional spectrum peak searching,the computation complexity is very large. So a propagator method (PM) based on fourth-order cumulants is proposed. This algorithm avoids eigenvalue decomposition on the cumulant matrix and the two dimensional spectrum peak searching, its estimated direction of departure(DOD) and direction of arrival (DOA) of targets are paired automatically, thus the computation complexity is reduced largely. At the same time, it has no claim on the number of receive arrays or receive arrays. Simulation results demonstrate that the proposed algorithm has good estimation performance.Finally, the traditional spatial smoothing algorithms in bistatic MIMO radar are introduced detailedly. A forward spatial smoothing algorithm based on fourth-order cumulants is proposed, which is aimed at the problem of the performance declining based on the spatial smoothing algorithms. This algorithm can prohibit the effect of the Gaussian colored noise effectively and achieve the correct estimation of the coherent targets.Simulation experiments are used to demonstrate the conclusions.