Time modulated array sideband suppression for joint radar-communications system based on the differential evolution algorithm

To satisfy the need of electronic system integration in civil and military, and mitigate the tension of spectrum resource, the demand for coexistence of radar and communication systems is increasing rapidly. As an important branch of radar-communications integration, the time modulated array (TMA) based coexistence method has been proposed recently. The TMA has an inherent drawback that there are many undesired sideband signals generated simultaneously. However, the existing TMA sideband suppression algorithms do not suit the radar-communications integration scenarios. In this paper, a time modulated array sideband suppression method for joint radar-communications system based on the differential evolution (DE) algorithm is proposed. We first introduce some facts of the time modulated array. Then, the radar-communication coexistence strategy is presented, and the form of integration signal is derived. Moreover, combined with a positive and negative alternating periodic modulation function, the TMA sideband suppression for radar-communications coexistence scenarios based on the DE algorithm is proposed. The sideband patterns of the TMA can be significantly lowered by optimizing the opening and closing moments of each element. Finally, the validity of the theoretical derivations is demonstrated via simulations.