Research On Dimension Reduction Signal Processing Algorithms For Conformal Array Based On Virtual Interpolation

Fast development of economical society and defense technology presents new requirement for array atenna,for example,installing array antenna on flight vechile,aerospace vechile or bullet train,to provide telemetering,telecontrol and reliable communication.Howerer,for reasons such as restriction of the shape or space of the carrier,classical array antenna can't meet the demand of practical application,so conformal array antenna come s into people's sight.Complicated electromagnetic characteristic of conformal array antenna leads to difficulties of modeling and signal processing,and chal enges the study and engineering application of conformal array.Virtual Interpolation Technique(VIT)maps conformal array antenna to plane array antenna by transformation matrix,and then classical signal processing algorithms designed for uniform linear array or plane array can be applied to process signals received by conformal array.Moreover,the transformation matrix,which is relative to structure of array antenna,can be solved off-line for once and stored in the system.The advantage of using VIT to process signal lies in simple principle,low computation,and easy implement.Signal processing algorithms for conformal array antenna based on VIT is studied in this thesis,especially for those conformal array antenna with regular shape.Main work of this thesis is composed of following three parts:(1)Analyze the case which MUSIC is applied to 3-dimension cylindrical conformal array,and propose Biased-MUSIC to slove the “shadow effects” of 3-dimension cylindrical conformal array;determine sub-arrays,azimuth and elevation sectors corresponding to signal DOAs through adaptive sub-array division,then search precisely using those sub-arrays and corresponding angle sectors to obtain DOA estimation results of high precision with low computation.(2)Combine VIT with the thought of coordinate rotation,propose fast DOA estimation emthod for 2-dimension based on coordinate rotation and VIT,this method takes advantage of the structure characteristic of 2-dimension cylindrical array,and reduces the number of matrix required by traditional DO A estimation method from several to one.(3)Study beamformer for 2-dimension cylindrical array using VIT and adaptive diagonal loading SMI algorithm,and discuss beamformer for dynamic target,result shows that assign current weight vector to new one will bring no error when sub-array switches from one to another for 2-dimension cylindrical array.