Research On Subarray Adaptive Beamforming And Interferometer Integration

As an important branch of array signal processing,beamforming technology has been widely used in communication,radar and electronic warfare systems.With the development o f smart antenna and the requirement of high speed communication in modern electronic warfare,large phased array is widely used.Beamforming in element level of array will increase hardware complexity and computation in system.In addition,the interferometer is widely used in the radar field because of its fastness,flexibility and simple engineering.However,the traditional interferometer can only distinguish one target.When the spatial signal component is complex,the interferometer can not obtain the accurate target orientation.Therefore,it is of great significance to combine adaptive beamforming technology with interferometer technology to realize anti-jamming interferometer.This thesis studies the problem,and the main work is:1.Beam forming algorithm based on uniform equidistant linear array is studied.It includes several beamforming algorithms for narrowband signals,and beamforming algorithms based on SDL array models for wideband signals.2.In subarray beamforming,because of the phenomenon of the array elements shared in uniform overlapped subarray resulting the noise correlating between channels,this paper presents a method of adaptive beamforming for such color noise background.Through noise power estimation,the noise correlation matrix of overlapped subarray structure is constructed to realize noise pre whitening.Simulation results show that the algorithm is better than the traditional beamforming algorithm in reducing the sidelobe and improving the output signal to interference noise ratio array.3.In order to slove the problem that the complex frequency components of wideband signal cause the output waveform distorted,in this thesis,we first study the SDL array model,which is constrained by applying a SRV parameter to the array response at different frequencies,so that the beam width of the beam is uniform at different frequencies,as for subarray beamforming,the spatial resampling method is adopted to achieve constant beamwidth.The simulation results show the feasibility of the algorithm,and the constant beam width technique can restore the desired signal.4.In this thesis,aiming at the combination of beamforming and interferometry,the feasibility of the interferometry technique based on beamforming is analyzed,and the method of ambiguity resolution is given,and the performance of interferometry is analyzed.The simulation results show that the accuracy of the measurement is higher than that of the conventional broadband beamforming technique.