The DOA Estimation Of Coherent Cyclostationary Sources In Impule-Noised Environments

DOA Estimation (Driection of Arrival:DOA) is a very important branch of spatial spectrum estimation, this method is widely used in various fields such as communication, radar, military, medical engineering. Most existing algorithms using MUSIC algorithm, which is the classic super-resolution algorithm. However, in practical application environment, "Cyclostationarity" is the common characteristic of many signals. Thus, to estimate DOA with this characteristic signal, has more advantages than the usual super-resolution algorithm. After much studies, many signal has Coherent problems, and some noise in the signal distribution is not only subject to the Gaussian distribution, but also subject to a stable a distribution. Therefore, based on much studies of MUSIC algorithm, this paper focus on the DOA estimation with coherent source which based on Cyclostationary signal, and improve the existing algorithm. In addition, for the traditional second-order cycle with serious degradation problems in impulse noise environment, this paper algorithms come up with a new algorithm.The main work of this paper is divided into four parts. First, based on some basic knowledge introduction of the DOA estimation, it simulates the MUSIC algorithm with array element number、the array element spacing、the number of snapshots and angle difference. Second, based on the introduction Cyclic MUSIC algorithm, compared the algorithm of Cyclic MUSIC and MUSIC algorithm with simulation, we can see that Cyclic MUSIC algorithm does have some performance advantages that MUSIC algorithm can not achieve from the simulation curve. Third, for the coherent source, it separately simulates the MUSIC algorithm and Cyclic MUSIC algorithm in both of the coherent signal and the non-coherent signals, it can be seen from the simulation that both of MUSIC and Cyclic MUSIC algorithm could accurately estimate the DOA of non-coherent signal which is being measured. Fourth, as Cyclic MUSIC algorithm is not an accurate estimation of coherent signals, based on the former spatial smoothing algorithm, we put forward the improved Cyclic MUSIC algorithm to achieve the DOA estimation of the coherent signals. For impulsed noise, a new algorithm is proposed on the basis of the improved algorithm, which is the spatial smoothing Cyclic MUSIC algorithm that has score low order, the new algorithm effectively solve the DOA estimation of Cyclostationary coherent signal in impulse-noised environment.