The Study On DOA Estimation Method For Underwater Acoustic Coprime Array

In recent years,with the sensor and array technology applications gradually increased,the array signal processing has become a hot spot.Direction of Arrival estimation that as a part of the array signal processing,after nearly a few decades of development,its theory has become increasingly mature and widely used in sonar,communications,radar,medicine and other fields.Due to environmental,hardware,energy supply and other aspects of the restrictions,the existing underwater acoustic array DOA estimation method in practical applications tend to slow operation,low accuracy and so on.The existing DOA estimation methods are mostly based on a uniform array.This method improves the spatial spectrum estimation angle by expanding the aperture of the array.Its cost of the project will increase dramatically.So,it is of great economic significance to propose a new array model without increasing the estimated cost.Based on the underwater acoustic array model and the signal processing method,a coprime array is proposed and compared with the existing algorithm to improve the estimation performance.From the point of view of application,in order to increase the aperture of the array,this paper introduces the concept of coprime array,and makes a brief exposition of its principle through the corresponding mathematical model analysis.Comparing the coprime array with traditional arrays and combining them.On the basis of the principle of compression sensing,the spatial spectrum estimation method and the sparse space algorithm are further compared,and the DOA estimation method based on sparse classes are designed.On the basis of the above theory,the paper also studies the DOA estimation method of subspace underwater acoustic coprime array.The subspace algorithm is combined with the underwater acoustic coprime array model,and the DOA estimation method based on the acoustic acoustic array is studied.In addition,this paper applies the sparse reconstruction algorithm to the DOA estimation of the acoustic coprime array and the performance of sparse reconstruction algorithm and traditional algorithm for DOA estimation are compared.In addition,the DOA estimation performance of the uniform array and the coprime array under the sparse reconstruction theory are compared.The results show that the proposed array structure is more suitable than the uniform array,and the proposed DOA method has higher accuracy than the previous DOA estimation method.The combination of the two methods makes the estimation effect much better than the traditional DOA estimation method,that is,in the case of the same number of elements,it can expand the array aperture,increase the number of identifiable sources and save economic costs.