杂波环境下的OFDM MIMO雷达波形设计

Waveform design for OFDM MIMO radar in presence of clutter

为提高杂波环境下的目标检测性能,基于正交频分复用（OFDM）多输入多输出（MIMO）雷达的波形和频率分集,提出了一种联合优化发射波形和接收滤波器的方法.首先以各天线发射功率和发射波形功率峰均比（PAPR）为约束条件,最大化输出信杂噪比（SCNR）为目标函数建立优化模型.然后利用循环迭代将优化问题分为两部分,并通过拉格朗日乘子法、半正定松弛（SDR）、Charnes-Cooper转换和随机化方法,求解得到最优发射波形和接收滤波器权值.仿真结果表明：所提方法的在满足PAPR约束的条件下,输出SCNR与理想波形的差距控制在0.3 dB以内,优于仅设计发射波形的方法和连续二次规划修正法,且PAPR的约束和序列长度变化几乎不影响算法性能.

Jointly optimization method of the transmit waveform and the receive filter was proposed in this paper.The waveform and frequency diversity of the orthogonal frequency division multiplexing（OFDM） multiple input multiple output（MIMO） radar were utilized to improve the target detection performance with clutter.First,the optimization model was constructed with the objective function of output signal-to-clutter-noise ratio（SCNR） maximization and the constraints of transmit power and peak-to-average power ratio（PAPR）.Then the optimization problem could be divided into two parts using cyclic iterative,and the optimal transmit waveform and receive filter could be obtained through Lagrange multiplier method,semi-definite relaxation（SDR）,Charnes-Cooper transformation and randomization methods.Simulation results show that the proposed method can control the gap between the output SCNR and ideal waveform within 0.3 d B under PAPR constraint,which is better than the method only design transmit waveform and successive quadratically constrained quadratic programing refinement（SQR）.Besides,PAPR constraint and sequence length hardly affect the performance.