The Realization Of The Incoherent Broadband Signal DOA Estimation Research

The DOA estimation of broadband signals is an important research direction of array signal processing.Up to now,people have found many excellent algorithms,among which eigenspace algorithm represented by classical MUSIC and ESPRIT algorithms has drawn broad attention in academic circle.The basis of this kind of algorithm has been widely used in engineering fields.Therefore,a lot of improved algorithms have been derived,which demonstrate strong vitality.This paper introduced and mostly focused on the relevant and improved algorithms of the narrowband signal DOA estimation,and further simulated and verified the narrowband signal DOA algorithms.The broadband signal DOA estimation algorithm has also been analyzed.According to their coherence,it can be divided into two parts:the ISM algorithm and the CSM algorithm.This paper mainly makes a research of the ISM algorithm,analyzed several improved algorithms,and particularly introduced the ISM algorithm for coherent signal estimation.The broadband DOA estimation algorithm has also been simulated and verified by using MATLAB.This part became the theoretical basis of DOA estimation in the research.Based on the study of above-mentioned algorithms,ISM algorithm was selected to be a guiding algorithm in this test.In the end,the most important progress of this research is that the ISM hardware implementation scheme is accomplished.This design is based on FPGA system,and has been divided into five large modules by achieved function.In orde of the data's flowing direction,these five large modules were arranged into smaller modules.The first module is FFT module,which targeting data digits is 12.It may achieve FFT 16 points.The second module is the covariance matrix generating module,which aim is to generate covariance matrix by using multiplier,accumulator and shifter.The third module is matrix real modules including adder,divider and pulse array multiplier,The fourth part is the covariance matrix eigenvalue calculation module,which calculate the matrix-real data's eigenvalue through JACOBI decomposition method,and then turns the maximum of element on this real diagonal matrix's off-diagonal into zero.The last part is spectrum peak searching module,through which the angle of the direction for receiving data signals can be acquired.It can be divided into four smaller modules to further implement:Looking-up table contrasted module,the inner producting calculation module,norm module to be solving and the comparing module of spectrum.