Research On Source Detection And Estimation Based On Vritual Array

The source detection and estimation are two popular research directions in array signal processing field.However,researches on these two directions are usually based on uniform linear array whose element spacing is limited by half wavelength,making it's difficult to extend the aperture.Nested array and coprime array are two kinds of nonuniform linear arrays whose structure are not limited by half-wavelength.The virtual array corresponding to the physical array can be used to handle more signals.It is worth noting that these nonuniform linear arrays can offer larger aperture than uniform linear arrays with the same number,for which the precision and angular resolution of the algorithm are improved.Therefore,this paper mainly focuses on source detection and estimation based on virtual array formed by nested array and coprime array.The main contents can be summarized as follows:The classical direction of arrival(DOA)estimation algorithms are investigated including MUSIC,Root-MUSIC and the spatial smoothing algorithm for coherent signals.The source detedtion algorithms like AIC/MDL criteria for Gaussion noise and GDE criteria for spatial color noise are alse be studied which is a stepping stone for the next algorithm research.The array structure and the feature of the virtual array formed by nested array are studied and the degree of freedom of nested array is analysed,too.And then a DOA estimation algorithm that can effectively solve more signals is investigated.Coprime array is another non-uniform linear array that can provide larger array aperture.According to the feature that its virtual array exists some holes,a DOA estimation algorithm based on low rank matrix recovery is proposed to fully used the array aperture which not only avoids the loss of freedom but also improves the algorithm accuracy and angular resolution.An algorithm based on MDL criterion for detection more sources is proposed.The outer product of the receiving data of the nonuniform linear array is defined,applying the array aperture offered by its virtual array to estimate the related parameters.Then by constructing parameterized probability density function and combined with the MDL criterion to realize the source detection.