Research On Beamforming Of Vector Sensor Array

Adaptive array beamforming is one of the main research fields in array signal processing.Many aspects of the military and civil affairs can not do without its applications.The conventional adaptive beamforming method only considers single-polar scalar arrays,which can only receive and use the spatial and temporal information of the incident signal,and can only make use of the polarization information of the signal a little.Electromagnetic vector sensor array consists of several identical vector sensors,that make it to obtain the polarization information of the incident signal.By extending the one-dimensional information processing to the six-dimensional,the efficiency of information transmission has been improved.This paper mainly focused on the beamforming methods of vector sensor array.Firstly,it studied the adaptive beamforming methods,then analyzed and compared the characteristics of different beamforming algorithms.Here we mainly dealed with the one-dimensional signal.In the later part of the research,by studying the characteristics of the vector sensor,the signal polarization was added.Then we extended one-dimensional signal into six-dimensional in the space,meanwhile the characteristics of the vector sensor and signal polarization were introduced into the adaptive array beamforming techniques.And in this way,the efficiency of the beamforming could be increased.In the part of beamforming on electromagnetic vector sensor array,two kinds of beamforming methods-co-polarized method and cross-polarized method,were mainly studied.Firstly,the co-polarized beamforming method was used to preserve the desired signal.According to its difference on polarized components,the co-polarized beamforming method could be divided into co-polarized beamforming in azimuth direction and co-polarized beamforming in pitch angle direction.After simulation and analysis of co-polarization beamforming for two different components by MVDR beamformer,we got the ideal beam pattern.There were no obvious differences in principles and effects between the two methods.But for the cross-polarized beamforming method,it was opposite to that of co-polarized beamforming method.Finally,the theory of convex optimization was introduced to beamform the electromagnetic vector sensor array signal.By combining the constraint conditions and characteristics of the polarization signal,the optimal weight vector could be obtained.By using the weight vector,the ideal adaptive beam pattern could be gotten.