Research On Precision Electronic Interference Technology Based On UAV Swarm Platform

Unmanned aerial vehicle(UAV)swarm system is characterized by its low cost,high robustness,and high mobility,which has outstanding advantages when adopted to implement electronic interfere.However,barrage jamming is usually employed as the main method of current electronic interfere,which is easy to cause accidental electromagnetic damage to our equipment near the target and causes great hidden dangers subsequently.By contrast,precision electronic interference is a new technology that can interfere with the specified target without affecting the availability of the friendly and neighboring devices by controlling the coherent synthesis or cancellation of the transmitted signals in the specific area.This paper focuses on the precision electronic interference technology based on UAV swarm and explores the localization error of UAVs,the optimization of UAV platform position,and grating lobe suppression.The main content is summarized as follows:(1)The localization error bound of the UAV platform that precision electronic interference can tolerate is derived,which provides a reference for the overall design of precision electronic interference.The optimization problem is established based on the nonstationary interference signal model in time domain,and the MFED algorithm for designing the interference signal is introduced.The influence of localization error on the precision interference effect is analyzed when the localization error is introduced to the objective function of the optimization problem established.Based on the reasonable assumption,the derivation is obtained that one-eighth of the carrier frequency wavelength of the transmitted signal is the localization error bound of the UAV platform that precision electronic interference can tolerate.(2)Two precision electronic interference algorithms based on the optimization of UAV platform position are proposed to further improve the precision electronic interference effect.The UAV platform position is considered as the optimization variable in the model of precision electronic interference,and the joint optimization model of UAV platform position and the interference signal is established.To solve the joint optimization model,the algorithm named PSO-MFED is proposed,where the position of the UAV platform is solved by Particle Swarm Optimization(PSO),while the fitness criterion of each particle is boiled down to the problem of designing the interference signal under the current UAV platform position,and MFED is adopted to solve the fitness criterion.Then,the algorithm named Hybrid-PSO is proposed.When the optimization space of the UAV platform position is relatively large,a fitness criterion estimation algorithm based on convex relaxation(Relax to Estimate,RE)is adopted to solve the subproblem,whose computational complexity is lower than that of MFED.When the optimization of the UAV platform position is relatively small,an efficient algorithm for solving the fitness criterion based on dominant eigenvector matching(DEM)is employed,whose computational complexity is between RE and MFED,but DEM is more accurate than RE in solving the fitness criterion.A threshold value is set to determine which algorithm to adopt to solve the fitness criterion in Hybrid-PSO.Both two joint optimization algorithms have better precision electronic interference effects than the stateof-the-art algorithm which only designs the interference signals.When the threshold value is set as 3%,the Hybrid-PSO algorithm can give both considerations to the accuracy and efficiency of the algorithm.(3)Considering the cases that each UAV equips with a single antenna or a uniform linear array respectively,two corresponding precision electronic interference algorithms based on grating lobe suppression are proposed to effectively suppress the serious grating lobes caused by the ultra-sparse distribution of UAVs.With respect to the case where each UAV equips with a group of the uniform linear array,the interference signal model is modified to extend the degree of freedom of signals,and a metric based on the L∞ norm is proposed to evaluate the grating lobes.Then,the special case that UAV equips with a single antenna is boiled down to the uniform linear array that only contains one element,and the L∞ norm is employed as the regularization term to establish the multi-objective optimization problem(MOP).The ADPM framework is adopted to design the interference signals under unimodular constraints.Next,the general case is considered where the uniform linear array contains N elements.By employing the BCD framework,the MOP model is decomposed into two subproblems regarding the amplitude and phase component of the transmitted signals in each iteration.In terms of the performance of the grating lobe suppression,two precision interference algorithms are better than the stateof-the-art algorithms,and the size of the uniform linear array is larger,the performance of the second algorithm is better,which will simultaneously attach a heavier computational burden in the implementation of the precision electronic interference.