Research On Small Aperture Processing Technology

With the miniaturization of the carrier equipment,such as vehicles and satellites,small aperture arrays have gradually becoming the research focus of array signal processing.It is difficult for small aperture to realize high resolution of signals,so there are some methods to solve the problems caused by the constraint of small aperture,such as using vector array instead of scalar array,joint processing in space and time domain,using wide linear processing technology.The main work of this thesis is as follows:Aim at the performance of exist algorithms will degrade when deal with non-circular signals and the high computational complexity which caused by space-time domain joint processing and matrix inversion,this thesis studied three widely linear(WL)reducedrank adaptive beamforming algorithms to solve above problems.Through using WL technique and Gaussian entropy criterion,the performance of anti-interference is improved,especially when dealing with non-circular signals.The simulation results show that the anti-jamming algorithms based on the Gaussian entropy criterion have stronger interference suppression ability,and its output signal-to-noise ratio(SINR)is greater than that based on the least mean-square criterion.Under the condition of polarization-space-time received signal model,polarization-space-time multi-domain joint reduced-rank minimum variance distortionless algorithms are studied.And after analysis,realized that the algorithm can't handle unsteady desired signal,because it doesn't have the ability to track the changes of the desired signal,so given two robust adaptive reduced-rank anti-jamming algorithms,and the simulation shows that all of them have the same performance for steady desired signal,but for the unsteady situation,the robust algorithms have better anti-jamming performance.Aim at arrays with small interelement spacing,this thesis analyzed the mechanical coupling structure of the Ormia ochracea and maximum likelihood estimate algorithm based on the mechanical coupling structure.The simulation verified the mechanical coupling structure can amplify the effect of amplitude and phase difference between two ears,and comparing with the standard array,the new algorithm has better performance.