Low probability of intercept based multicarrier radar jamming power allocation for joint radar and wireless communications systems

Due to the high demand for new wireless services and shortage of available radio frequency (RF) spectrum, joint radar and communication system is considered as a coexistence solution to the RF spectrum congestion problem. Therefore, joint radar and communication system has become an attractive platform for target parameter estimation. In this study, the problem of low probability of intercept (LPI) performance based orthogonal frequency division multiplexing (OFDM) radar jamming power allocation is addressed for a joint radar and communication system. Given the knowledge of the radar transmitted signal, the communication signal, the channel impulse responses, and the propagation losses of the corresponding channels provided by the jammer, three different LPI-based criteria for radar noise jamming power allocation are proposed, whose purposes are to minimise the total noise jamming power by optimising the multicarrier jamming power allocation while the achieved mutual information between the received echoes and the target impulse response is enforced to be less than a predefined threshold. The presented optimisation problems are solved analytically and their solutions represent the optimum power allocation for each subcarrier in the OFDM jamming waveform. Numerical simulations show that the LPI performance of the jammer is considerably improved by the proposed strategies.