Direction-of-arrival Estimation For Coprime Array Configurations Base On Compressive Sensing Approach

Direction of arrival(DOA)estimation technology is one of the most popular research direction in the field of modern signal processing.Most traditional DOA estimation methods are studied based on uniform linear arrays,they usually require a high demand for the snapshot number,signal to noise ratio,and more parameters because of the limited number of array elements.Therefore,how to increase the degrees of freedom of the array as much as possible in a circumstance of the limited number of arrays elements and how to achieve high resolution DOA estimation technology by using a little snapshot number at the same time has important research significance.In order to solve the above problems,this paper studied the DOA estimation methods for coprime array configurations base on compressive sensing approach.Coprime array is a new array structure which has been proposed in recent years to improve the degrees of freedom of the array,it overcomes the shortcoming of the uniform linear arrays in which the number of the signal estimation are less than the number of the array elements.Meanwhile,this paper also introduces compression perception approach into DOA estimation algorithm,using spatial sparsity of the incident signal to improve the accuracy of the angle estimation.Based on this,we introduced two models with off grid targets to solve the problem of the mismatch between the sparse signal and the grid which is happened in compression perception approach,thus the performance of the angle estimation is further improved.The main work of this paper are listed as follows:1.The DOA estimation algorithm and the background knowledge of co-prime array and CS theory are introduced.2.Particularly introduce the mathematical model of array signal processing and several classic narrowband DOA estimation algorithm,then we analyze the CS theory.and the mathematical model of DOA estimation based on compressed sensing theory.3.First analyze the structure and the degrees of freedom of the simple co-prime array and the extension co-prime array.Then we expound two DOA estimation algorithm based on co-prime array,which include the co-prime array DOA estimation based on SS-MUSIC algorithm and the co-prime array DOA estimation based on L1-convex optimization algorithm,and we make a simulation and comparison analysis in these two co-prime array towards these two algorithms respectively.4.To solve the problem of the mismatch between the sparse signal and the grid,we introduce two models with off grid targets and applied them to the co-prime array DOA estimation based on L1-convex optimization algorithm,we demonstrate that these two models with off grid targets can improved the performance of algorithm,at last we analyze the performance of the two off grid algorithms by simulation.