信杂噪比约束下基于互信息的雷达波形设计

在发射信号能量有限情况下, 雷达性能界定了信杂噪比(signal to interference plus noise ratio, SINR)的作用范围, 而雷达波形设计就受到SINR的约束。对此, 以提升认知雷达目标估计性能为目标, 根据相对熵的非负性条件, 从理论上推导了互信息的边界和SINR的作用阈, 并在信号相关杂波环境下, 提出一种SINR约束下基于最大化互信息的波形设计方法。仿真验证了互信息和SINR之间的单调递增、阈值限定和相互约束关系, 结果表明SINR约束下的优化波形能更充分利用发射能量, 在有目标且杂波弱的频率点提取目标信号。

MI-based radar waveform design under SINR constraint

In the case of limited transmitted signal energy, the radar performance limits the range of signal to interference plus noise ratio (SINR), and the radar waveform design is constrained by the SINR. Therefore, in order to improve the target estimation performance of cognitive radar, based on the non-negative condition of relative entropy, the boundary of mutual information (MI) and the threshold of SINR theoretically are derived. Then, in the signal-dependent clutter environment, a maximizing MI based waveform design method under SINR constraint is proposed. Simulation results verify the monotonous increase, threshold limit and mutual constraint relationship between MI and SINR. The results show that under the constraint of SINR, the optimal waveform can make full use of the transmitted energy and extract signals at the frequency bins where the target and the clutter is weak.