Method For Suppressing Grating Lobe Interference Of Linear Array

Aiming at the problem which is caused by the sparse array,this paper discusses the methods of suppressing grating lobe interference(GLI)both in narrowband and wideband circumstance,and promotes these algorithms from the pressure-sensing arrays to the vector-sensing arrays.The feasibility and validity of the algorithm are verified through careful simulation and data processing.Firstly,the advantages and disadvantages of commonly used methods of suppressing GLI are listed.Meanwhile,the current situation and development of vector-sensing array signal processing techniques are introduced.Then the GLI generating mechanism and impacts of uniformly-spaced linear array are analyzed.Based on this,the research and experimental simulation of the grating lobe interference suppression method are carried out.We studied the method of suppressing GLI in narrowband case.Three kinds of methods are carried out in this case,including combined array method based on sub-array partitioning,virtual interpolation algorithm based on LS method and array sound intensity estimator.Simulation indicated that extending the combined array method and virtual interpolation method from pressure-sensing array to vector-sensing array,they can obtain better results of GLI suppression.The combined array method can only restrain GLI instead of eliminating it,which can be improved by the method of prediction and elimination of the grating lobes.Commonly used virtual interpolation algorithm would lead to DOA estimation failed,studied results show the error can be successfully corrected through diagonal losing.The array sound intensity estimator needs the velocity information of the sound field,only applies to the vector-sensing array.Finally,we studied the method of suppressing GSI in wideband case.Here are also three kinds of methods carried out in this case,including combined array method based on sub-array partitioning,virtual interpolation algorithm based on sum of time delay and beam output weighting algorithm.The first two methods are used on the condition of a single target detection,suppress the GLI in order to obtain better performance of their own estimation and detection.The first two methods obtain good performance in the condition of single target detection and parameter estimation,however,failed in multi-targets detection.In the case of multi-targets detection,we improved the beam output weighting algorithm by utilizing the knowledge of wideband GLI position and width prediction to suppress GLI and enhance weaktarget detection ability through output weighting.Simulation results show that this method is suitable for both pressure-sensing array and vector-sensing vector.