The Research Of The DOA Estimation For Different Array Shapes And The Performance Of An Array With Defect Elements

Array signal processing technology is an important branch of signal processing, and be as the core technology and the main direction of development in many application areas, such as phased array technology in radar field, smart antenna technology in communications and high-resolution direction estimation in the field of electronic countermeasures. And high-resolution direction estimation algorithms is a hot issue in array signal processing research, mainly to solve the high-precision angle estimation. So we investigate the angle estimation in the different shapes of the array and array performance with defect array elements, in combine with the specific "Eleventh Five Year" research project.Firstly, for uniform linear array, a minimum norm method based on DFT is researched. Since the classic MUSIC algorithm requires eigenvectors and spectrum peak search, the computation of the algorithm is large. The process of eigen-decomposition is instead of the product of DFT matrix and array data matrix, basis of signal subspace is modified by minimum norm method in the same, so the noise subspace and array spaces have better orthometric. Then the algorithm have less computation better performance to classic algorithm.Secondly, for uniform circular array, a quick DOA estimation algorithm based on ESPRIT is given, compared with ESPRIT algorithm in pattern space. Both the azimuth and elevation angle need to be searched for the MUSIC algorithm in uniform circular array, and the computation is large. The ESPRIT algorithm in pattern space is a closed-form algorithm, so it has less computation and less performance. But the quick DOA estimation algorithm based on ESPRIT roughly estimate the angles by the way of closed-form ESPRIT algorithm,and then the final estimates will be got through the process of local search by the MUSIC algorithm used for uniform circular array. The result is that the quick DOA estimation algorithm based on ESPRIT have high-resolution angle estimation and less computation in the same time.Finally, the effect of array pattern with defect array elements in practice application is researched. In the case of uniform linear array, the location of defect array element is different, the result of array pattern is different, equal to the array shape is different. In the same, in the case of uniform circular array, the location of defect array element is different, the effect of array pattern will be different. But the uniform circular array have geometry-symmetric properties, that is the effect of array pattern is same by rotate the pattern when defect array element is different. So the effect of the uniform circular array pattern when array has defect array element is small than uniform linear array.