Research On Direction-of-Arrival Estimationof Distributed Sources In Massive MIMO Systems

Direction of arrival(DOA)estimation is an important research direction of array signal processing.It is also concerned in the field of engineering applications In wireless mobile communication system,DOA estimation plays a key role in tracking and location of mobile users,Therefore,DOA estimation algorithm research has important significance both in theory and practice.The traditional DOA estimation algorithm assumes that the signal model is a point source model,but as people continue to study,found that the transmitted signal is affected by the multipath effect,so that the energy of the signal is spread,and can not be transmitted at a point.In order to apply the DOA estimation algorithm in practice,a distributed source model is proposed.In addition,in the practical application,the real-time processing algorithm is also very important,therefore,in the coherent distributed source model,this paper presents a new method(M-U-ESPRIT algorithm)for fast DOA estimation in real domain.In this algorithm,the unitary ESPRIT algorithm is combined with the multistage Wiener filter method,so it is not necessary to decompose the covariance matrix.The computational complexity of the algorithm can be reduced rapidly under the premise of guaranteeing the estimation performance.In the field of wireless mobile communication,Massive MIMO system has many advantages such as high spectrum efficiency and high receiving power etc.In the past five years it has been rapid development,and has become the forefront of research.In this paper,we apply coherently distributed source DOA estimation algorithm to Massive MIMO system.In the Massive MIMO system based on the uniform rectangular array,the approximate expression of the two-dimensional coherent distributed source direction vector obeying the Gauss distribution is derived.On this basis,the unitary ESPRIT algorithm and the fast DOA estimation method are applied to the Massive MIMO system,and the two-dimensional CDU-ESPRIT algorithm and two-dimensional CDM-ESPRIT algorithm are obtained.In this paper,a large number of computer simulation experiments are carried out for these two algorithms.The simulation results show that the two algorithms can estimate the elevation and azimuth accurately,and have a good estimation performance.