MI-Based Robust Waveform Design in Radar and Jammer Games

Bin Wang,Fengming Xin,Xu Chen,Xin Song

doi:10.1155/2019/4057849

Abstract

Due to the uncertainties of the radar target prior information in the actual scene, the waveform designed based on the radar target prior information cannot meet the needs of parameter estimation. To improve the performance of parameter estimation, a novel transmitted waveform design method under the hierarchical game model of radar and jammer, which maximizes the mutual information (MI) between the radar target echo and the random target spectrum response, is proposed. In the hierarchical game model of radar and jammer, the radar is in a leading position while the jammer is in a following position. The strategy of the jammer is optimized based on the radar transmitted waveform of previous moment, then the radar selects its own strategy based on the strategy of the jammer. It is generally assumed that the radar and the jammer have intercepted the real target spectrum and then the optimal jamming and the optimal transmitted waveform spectrum are obtained. However, the exact characteristic of the real target spectrum is hard to capture accurately in actual scenes. To simulate this, the real target spectrum is considered to be within an uncertainty range which is confined by known upper and lower bounds. Then, the minimax robust jamming and the maximin robust transmitted waveform are designed successively based on the MI criteria, which optimizes the performance under the most unfavorable condition of the radar and the jammer, respectively. Simulation results demonstrate that the robust transmitted waveform design method guarantees the parameter estimation performance effectively and provides useful guidance for waveform energy allocation.

Highlights

Cognitive radar (CR) is a new radar system concept proposed in recent years
To impair the estimation performance, the minimization of mutual information (MI) means that the radar target echo contains little information on the target, which will result in poor performance of the radar transmitter
The results show that the optimal jamming solution based on MI can be obtained by water-filling operation which assumes that the target spectrum H(f) and transmitted waveform of previous moment X(f) are greater than zero at each sampling frequency

Summary

Introduction

Cognitive radar (CR) is a new radar system concept proposed in recent years. This system is inspired by the bat echolocation, which improves the system performance of the radar through using the feedback structure from the receiver to the transmitter to optimize the transmitted waveform based on the recognition of the target and the scene [1]. The minimax robust jamming and maximin robust transmitted waveform techniques under the established hierarchical game model above based on the MI are developed successively. By considering the uncertainty of the target spectrum, the MI-based minimax robust jamming and maximin robust transmitted waveform techniques are proposed successively. The minimax robust jamming and maximin robust transmitted waveform design methods optimize the performance under the most unfavorable condition of the jammer and the radar transmitter, respectively. Their behaviour with regard to the uncertainty of target spectrum is analyzed. As the method proposed in this paper assumes that the radar is more powerful than the jammer, the radar won this electronic warfare, and the transmitted waveform designed by radar maximizes the estimation performance of radar

Signal Model and Problem Formulation

Maximin Robust Waveform Design

Simulation and Results

Conclusion

Conflicts of Interest