Research On Low Complexcity DOA Estimation Algorithm For Massive MIMO Systems Based On Propagtor Method

As a key technology to improve the spectrum efficiency of wireless communication systems,MIMO has been widely used in fourth-generation mobile communication systems.Currently,Large-Scale MIMO is also recognized as one of key factors for next-generation mobile communication systems.Existing studies show that the Beam-forming can effectively mitigate the inter-cell interference to improve the performance of Large-Scale MIMO systems.However,its premise is the accurate angle parameter estimation of the target,so that,the research of DOA estimation for massive MIMO systems is of great significance.The spatial spectrum estimation can achieve high-resolution direction finding for multiple targets in spatially different directions.However,the existing algorithms commonly have a large amount of computation.It is necessary to reduce the complexity and enhance the real-time performance of these algorithms.The Propagator Method,a low-complexity and strong real-time algorithm,was proposed at the end of the 20 th century.Two improved algorithms based on PM algorithm including MPM and PM-ESPRIT Method are proposed in this paper.Besides,it alsostudies the estimation performance of these algorithms in massive MIMO systems.The main work of this paper can be divided into two parts.The first one of it is,for the PM algorithm's low performance under the circumstances such as low signal-to-noise ratio,little snapshots and the need for peak-searching,to propose MPM and PM-ESPRIT algorithms and promote them to two-dimensional situations.The second part is to simulate the estimation performance of each algorithm in Large-Scale MIMO arrays,including large-scale uniform linear arrays and uniform rectangular arrays,by computer experiments.The simulation results show that the Large-Scale MIMO system inhibits small-scale fading and additive noise well.MPM and PM-ESPRIT algorithms,except improving the performance of the PM algorithm,compared with the traditional DOA estimation algorithms,have lower computational complexity.Therefore,the proposed two algorithms in this paper are suitable for Large-Scale MIMO systems.