Minimax robust jamming techniques based on signal-to-interference-plus-noise ratio and mutual information criteria

Jamming in defence applications is increasingly difficult because of advanced signal processing countermeasures. In this study, task-dependent power-constraint optimal jamming techniques are investigated. To prevent the target from being detected, a novel jamming technique is proposed to minimise the signal-to-interference-plus-noise ratio (SINR) of the radar for extended known and stochastic target. To impair the parameter estimation performance, another jamming technique is proposed which minimises the mutual information (MI) between the radar return and the stochastic target impulse response. The optimal jamming spectrum is obtained assuming that the jammer has intercepted the radar waveform generally. However, the precise characteristic of radar waveform is impossible to capture in practice. To model this, it is considered that the waveform spectrum lies in an uncertainty class confined by known upper and lower bounds. Then, the minimax robust jamming is designed based on the SINR and MI criteria, which optimises the worst-case performance. Results demonstrate that the two criteria lead to different optimal jamming results but they have a close relationship from the Shannon's capacity equation which provides useful guidance on jamming power allocation for different jamming tasks. However, their behaviour with respect to the waveform uncertainty is the same.