Research On DOA Estimation Method Based On Infinite Normal-Fractional Low Order Moments In ? Noise Background

Multiple-input multiple-output radar is a new type of radar system.Because of its high resolution,good stability,strong anti-interference ability and high system freedom,it has been widely used in the field of signal processing.Among them,the angle of arrival estimation of monostatic MIMO radar is one of the research hotspots of spatial spectrum estimation,which has attracted wide attention from scholars at home and abroad.Traditional DOA estimation algorithms are mostly based on Gaussian noise,but in a large number of observation experiments,it is found that the measurement background noise is a kind of non-Gaussian noise with exponential tailing properties.Studies have shown that the noise can be described well with a stable distribution.Since there is no finite variance in the stable distribution of ?,the performance of the classic subspace-like DOA estimation algorithm is degraded,serious or even invalid.Based on the above problems,this article does the following research:1.The mathematical model of the received signal of the monostatic MIMO radar and the related properties of the stable distribution are studied,and the classical ? stable distribution noise suppression method is analyzed in detail;2.Aiming at the problem of the performance degradation of the classic FLOM operator with smaller eigenvalue ? and lower signal-to-noise ratio,this paper proposes a unitary ESPRIT algorithm based on infinite norm-fractional low-order moments.Through computer simulation,a detailed comparison of the success probability,root mean square error,and calculation amount with the traditional classic FLOM-MUSIC algorithm and ROC-MUSIC algorithm shows that the improved algorithm has a lower eigenvalue ? and a smaller trust value.Under the noise ratio,DOA estimation performance is significantly improved;3.Aiming at the problem of DOA estimation of coherent signal sources under ?stable distributed noise,this paper uses the Toeplitz matrix reconstruction algorithm and the infinite norm-fractional low-order matrix to combine,and compares with the improved front and back spatial smoothing algorithms through simulation.It shows that the improved algorithm can still accurately estimate the angle of coherent signal sources at a lower signal-to-noise ratio,and overcomes the problem of the number of elements of the spatial smoothing algorithm varying with the number of sources and the problem of array aperture loss.