Amplitude-phase Consistency Calibration And Hardware Implementation In Adaptive Arrays

Array signal processing is a main method used to analyze and process airspace signals and has a wide range of applications in communications,radar,sonar,seismic exploration and other fields.As an important research direction of array signal processing,the traditional super-resolution DOA estimation and adaptive beam-forming(ABF)algorithm are based on the ideal steering vector with the white Gaussian noise in the background,ie,array errors are not considered.However,in practical applications,various array errors,such as inconsistent amplitude-phase characteristics of the array channels,array element position perturbation,and mutual coupling effects between the array elements,can make the true steering vector inconsistent with the theoretical value,leading to a decrease in the performance of the DOA estimation algorithm and the beam-forming algorithm.This thesis mainly studies the influence of amplitude and phase error of array channel,amplitude and phase consistency calibration algorithm and its hardware implementation.Firstly,based on the DOA estimation algorithm and BF technology,this thesis analyzes the MUSIC super-resolution direction finding algorithm and the ABF algorithm based on the LCMV optimal filtering criteria.Then,the cause of the array errors is analyzed and summarized,the mathematic model of amplitude and phase errors,mutual coupling and position disturbance between the array elements is established.Based on this,the effect of inconsistency of the channel amplitude and phase characteristics on the performance of the MUSIC algorithm and the LCMV adaptive beam-forming algorithm is simulated and analyzed.During this process,the effect of the amplitude and phase errors on beam pointing and side lobe levels is particularly studied when the amplitude distributions and phase errors are subject to different statistical distributions.Then,the performance of a common channel amplitude and phase consistency calibration algorithm in engineering is analyzed,the single-aided source calibration algorithm in the active calibration algorithm is simulated and analyzed.In addition,the WF algorithm in the self-calibration algorithm is studied for its stability,and the frequency domain equalization algorithm of the channel equalization algorithm is simulated and analyzed,too.At the end of this thesis,combined with the practical application,the design scheme of the array channel amplitude and phase consistency calibration module is introduced in detail,among which,the design of the program of each functional module in FPGA is introduced specially.In addition,the functional verification scheme of channel amplitude and phase consistency calibration module was designed.The feasibility and effectiveness of the calibration algorithm were verified by comparing the results of the simulation and waveforms captured online.