Research On System Level DOA Estimation Algorithm Based On Correlation Interferometer And WSF

Direction of Arrival(DOA)estimation is an extremely important research direction in array signal processing.In the system-level DOA estimation application,the correlation interferometer algorithm(CIA)is an important algorithm,but it has the following drawbacks:there is phase ambiguity and mirror baseline symmetry in the direction finding;only one position estimate can be solved at the same time.These two issues seriously hamper the application of system-level DOA estimation.Aiming at the problem of phase ambiguity and radial baseline symmetry,this thesis proposes an improved correlation interferometer algorithm(ICIA).First,the time difference between the signals arriving at each element is converted into a phase difference,and the obtained phase difference is compared with 360°,and the obtained quotient and remainder are recorded;then the remainder is subjected to quadrant classification,and the signal is solved by a conventional correlation interferometer algorithm.The initial estimate,finally,the inverse application solves the final angle of the solution.Compared with the traditional interferometer algorithm,the improved algorithm improves the signal estimation accuracy,reduces the computational complexity and improves the real-time of the direction finding.For the correlation interferometer algorithm,only one signal azimuth estimation problem can be solved at the same time.This thesis introduces an improved weight subspace algorithm(WSF).The WSF algorithm has a superior DOA estimation performance,but WSF involves multi-dimensional nonlinear optimization in the solution process,and the computational complexity is relatively high,which hinders its application in system-level DOA estimation.In order to reduce the computational complexity of WSF,this thesis divides the solution process into two parts: the solution of Genetic Algorithm(GA)initialization space and the accurate DOA estimation.Solving the GA initialization space: first assuming that there is only one signal to find the rough DOA estimate;then assuming that there are two signals,fix the first DOA estimate obtained,and get the second rough DOA estimate;until all the solutions are solved The estimated value of the signal is then introduced into the estimated value of the solution to solved.The initialization space of the GA.Accurate DOA estimation;use the improved WSF algorithm to solve accurate DOA estimates in the determined GA search space.The experimental results show that the algorithm greatly reduces the computational complexity of WSF in the solution process and improves the real-time performance of DOA estimation.Finally,a lot of experiments are carried out in this thesis.Through the analysis and research of the experimental results,it is proved that the improved interferometer algorithm proposed in this thesis successfully solves the mirror baseline symmetry problem and phase ambiguity problem,and improves the accuracy of direction finding.The improved WSF algorithm proposed in this thesis greatly reduces the computational complexity,improves the real-time performance of direction finding,and is of great value for spatial spectrum estimation.