Amplitude And Phase Errors And Side Lobes In Digital Beamforming

Digital Beam Forming(DBF)is an important array signal processing technology with high military and civil value.After long-term development,its basic theory is quite mature.However,in practical,various types of errors lead to model mismatch,excessive sidelobes introduce unexpected interference,resulting in serious performance degradation.Therefore,mismatch calibration and sidelobe suppression are necessary.In this paper,amplitude-phase error calibration,low-grating lobe multi-beam forming based on uniformly illuminated contiguous subarrays and the robust low sidelobe adaptive digital beam forming(ADBF)techniques are studied.Main works include:1.Firstly,this thesis studies several single reference aided array amplitude-phase error calibration algorithms,and an algorithm based on reference source location error compensation named LEC-APC is derived to handle the reference location bias problem;2.Secondly,to suppress grating lobes in uniformly illuminated contiguous subarrays,a Particle Swarm Optimization(PSO)based algorithm named PSO-X-BSGL is derived,which uses PSO to compute the low-sidelobe optimum weights;3.Thirdly,for the high sidelobe and insufficient snapshot number problems in classical robust adaptive digital beamforming(ADBF),a precise,fast and single-snapshot DOA estimation method based on Compressive Sensing(CS)named ICS-DOA is studied,and a single-snapshot robust low sidelobe ADBF algorithm named ICS-SRL based on iterative CS is derived,which fixes the steering vector,nulls the interference and suppresses the sidelobe effectively only with single snapshot;4.Finally,to overcome the defects of ICS-SRL,based on convex optimization and iterative CS,a single-snapshot robust low sidelobe ADBF algorithm named C-ICS-SRL is proposed,which has lower sidelobe and higher flexibility.