Jamming Power Allocation Strategy For MIMO Radar Aided By Reconfigurable Intelligent Surface

Multiple Input Multiple Output(MIMO)radar has become a research hotspot in new radar systems due to its flexible array layout,good anti-stealth ability,antiinterception ability,and anti-jamming ability.Reconfigurable Intelligent Surface(RIS)has recently received a lot of attention in wireless communication and radar fields because of the ability to customize wireless channels to achieve intelligent directional reflection of signals.By adjusting the amplitude and phase of each reflection element,RIS can achieve the coherent superposition of multiple signals to enhance the useful signal power,which can significantly improve the performance of MIMO radar for target detecting,locating,tracking and identifying through proper design.Therefore,RIS technology has great application potential in MIMO radar,and it is necessary and urgent to study jamming strategies for RIS-aided MIMO radar.However,at present,the research on jamming for RIS-aided MIMO radar is still in the exploratory stage.RISaided MIMO radar have high environmental adaptability and energy efficiency,so if conventional MIMO radar jamming strategies are directly used to jam RIS-aided MIMO radar,the jamming performance will be rapidly degraded due to insufficient jamming resources and failure to consider the impact of RIS.In addition,the highly non-convex nature of the RIS phase design will also increase the difficulty of solving the jamming strategy.How to design an effective jamming strategy for RIS-aided MIMO radar is a pressing issue.To address this problem,this paper considers the cooperation between multiple jammers,and explores jamming strategies for both RISaided MIMO radar multi-target detection and multi-target localization scenarios from the perspective of jamming power allocation,combining such as fractional programming,alternating iteration,and semi-positive definite release techniques.The main contributions are as follows:(1)This paper addresses the issue that a rationally designed RIS can significantly improve the performance of MIMO radar,and summarizes the development status of researches on MIMO radar jamming at home and abroad.it is found that there are no jamming techniques for RIS-aided MIMO radar,indicating the necessity of this research.The feasibility of jamming RIS-aided MIMO radar is analyzed on the basis of a generalization of basic radar jamming strategies,and it is clear that this paper aims to jam the RIS phase design and conducts jamming strategy research from the perspective of power allocation.(2)This paper explores a joint jamming radar receiver and RIS jamming power allocation algorithm for a RIS-aided MIMO radar multi-target detection scenario.In order to ensure that the overall jamming effect meets the performance requirements,this paper investigates the jamming power allocation algorithm in the worst case when the MIMO radar obtains the maximum total signal to jamming noise ratio through the optimal phase design of the RIS,and converts it into an alternating iterative problem of fractional programming and geometric programming by means of equivalence substitution and semi-positive definite release for solution.In addition,the impact of the introduction of RIS to the MIMO radar on the jamming power allocation preferences and jamming performance is explored by varying the relative position between the target,the radar and RIS,as well as the arrangement of the RIS.The simulation results verify the effectiveness of the algorithm.(3)This paper explores the two jamming power allocation algorithms of joint jamming radar receiver and the RIS as well as separate jamming radar receiver in the multi-target location scenario of the RIS-aided MIMO radar.The paper still formulates two jamming power allocation strategies in the worst case to guarantee the overall jamming performance,that is,when the optimal RIS phase design makes the MIMO radar obtain the minimum sum of weighted Cramér–Rao bounds,the jammer should maximize this minimum sum of weighted Cramér–Rao bounds to guide the jamming power allocation,and then the optimization strategies can be solved by converting them into alternating iterative problems of convex programming using inequality release techniques.In order to improve the jamming effect as much as possible,this paper analyzes and compares the performance of the two jamming power allocation algorithms by changing the relative position between the target,the radar and the RIS as well as the arrangement of the RIS,so as to select the power allocation algorithm with better jamming performance to counter the RIS-aided MIMO radar at the locating stage and reduce its localization accuracy to a greater extent.Simulation results verify the effectiveness of the algorithm.