The 2-d DOA Estimation System Design Based On Microphone Array

The active target location technology has been studied widely,but its concealment and security is difficult to guarantee all the time.The passive sound source localization technology based on the microphone array,has become a new research subject of the target location technology,with broad application prospects and scientific value.There are currently many problems in the passive sound source localization system,such as low location accuracy,low angular resolution and only for a single sound source.Therefore,I design a two-dimensional DOA estimation system based on the uniform rectangular array and the high-resolution spectral estimation algorithm in this paper.The specific research contents of this paper include:(1)The application fields and recently research of microphone array are introduced,and the development and research progress of the high-resolution spectral estimation algorithm is summarized.(2)The system composition and theoretical basis of DOA estimation technology is introduced.The spatialcharacteristics of the far field narrowband signal source is mainly studied.The signal source models are established of the dependent signal source,the dependent signal source and the two coexisting.The steering vector matrix model is deduced based on the uniform rectangular array.(3)The algorithm of signal source numbers estimation is studied based on the uniform linear array.And the software simulation is conducted of the information theory methods,which based on eigen-decomposition.The MDL criterion is selected as the signal source number estimation algorithm of the thesis.The 2-d MUSIC algorithm and the improved 2-D MUSIC algorithm are deduced and the 2D-ES-DOA algorithm is proposed,which based on the uniform rectangular array.The simulation results show that the proposed algorithm is superior to the two-dimensional MUSIC algorithm and the improved two-dimensional MUSIC algorithm,and has the decoherence ability.The 2-D ESPRIT algorithm and the 2-D Unitary-ESPRIT algorithm are deduced,and the simulation results show that the latter has a decoherence ability.(4)The electret condenser microphone is chosen,and a uniform rectangular microphone array is designed,based on the spatialcharacteristics of the far field sound source.The key properties of the microphone are tested.The main chip of the multi-channel synchronous data acquisition card is introduced,and the function testing process isnarrated of the card.(5)MAT-File format is unscrambled,which is used to the software debugging and data storage of this paper.The software realization of the eigen-decomposition,the matrix inversion and pseudo inverse,the 2-D coordinate system and the 3-D coordinate system,the 2-D graphics display and the 3-D graphics display are analyzed emphatically.The 2-D DOA estimation simulation system is finished based on VC++ software,which added the 2-D DOA estimation algorithm of this paper and could complete the 2-D DOA estimation and display of the signal sources.The 2-D DOA estimation system could realize the 2-D DOA estimation of the far-field or low-altitude multiple sound source targetsin the air,and has potential application prospects in security protection and enemy monitoring etc.The software system based on VC++ is easier for re-development,and lays a foundation for engineering application.