Research On DOA Estimation Algorithm Based On Propagation Operator

Direction of Arrival(DOA)estimation is an important branch of array signal processing.It is widely used in radar,sonar,geological survey,medical diagnosis and other fields,but traditional subspace algorithms usually require complex computation such as eigenvalue decomposition,which increases the complexity of the algorithm,especially in large-scale antenna arrays,high complexity will undoubtedly affect the comprehensive performance of the algorithm.Therefore,this paper focuses on the research of low complexity,efficient and fast estimation algorithm.First of all,one-dimensional estimation is studied.In this paper,a low complexity fast estimation algorithm,DPLA algorithm,is proposed by using the special structure of the dual parallel linear array.Based on the shift invariance of the array on the displacement vector,the algorithm is finally converted into the rotation invariance of the signal,so that the signal between the sub arrays is only one rotation factor different,and the noise subspace can be obtained by linear transformation of the first column elements of the joint cross covariance matrix,Then,the root algorithm is used to get the estimated value,which effectively avoids the complex calculation such as eigenvalue decomposition and reduces the calculation amount.Through the comprehensive analysis of the complexity and simulation results,it is concluded that the comprehensive performance of DPLA algorithm is better than that of the reference algorithm.Secondly,the two-dimensional estimation is studied.Although the propagation operator method(PM)uses linear transformation instead of eigenvalue decomposition to reduce the computational cost,the complex two-dimensional spectral peak search makes it a failure.Therefore,based on the core idea of PM algorithm and the special structure of the array,an improved PM algorithm is proposed in this paper.In this algorithm,the propagation operators are constructed for the x-axis,Z-axis and the total array of L-type array respectively,and then the rotation factor matrix containing angle information is obtained by linear transformation of the three propagation operators,and then the two-dimensional DOA estimation value is obtained by angle pairing,which effectively avoids spectral peak searching and reduce calculation amount.Finally,the complexity and simulation results are analyzed synthetically,and the conclusion that the performance of the improved PM algorithm is better than that of the reference algorithm is obtained.