基于凸优化的自适应子载波调制OFDM雷达波形优化设计

Optimal Design of Adaptive Subcarrier Modulation OFDM Radar Waveform Based on Convex Optimization

为解决正交频分复用(OFDM)雷达的发射-接收联合优化问题,提出了基于凸优化的自适应子载波调制的波形优化方法。针对高距离分辨目标检测,给出基于最优匹配照射的子载波调制OFDM雷达系统模型。建立在OFDM信号峰均比(PAPR)约束下最大化匹配滤波器输出信噪比(SNR)的目标函数,将其转化为二阶规划标准形式并采用凸优化算法进行求解,优化发射波形。仿真结果表明基于凸优化方法的自适应子载波调制OFDM雷达信号波形的SNR为30.1 dB,PAPR为0.8 dB。SNR受到3.7 dB的损失,但大大降低了PAPR,实现了信噪比和峰均比之间的良好折中。

To solve the problem of the transmit-receiver joint optimization for the orthogonal frequency division multiplexing（OFDM）radar,an adaptive subcarrier modulation waveform optimal method based on convex optimization is proposed.Aiming at the detection of a high range resolution target,an adaptive subcarrier modulation OFDM radar system model based on optimal matching illumination is given.The target function for maximizing the signal-to-noise ratio（SNR）of the matched filter under the constraint of OFDM signal peak-to-average power ratio（PAPR）is built.It is converted into the standard form of a second-order program and solved by a convex optimization method,and the transmit waveform is optimized.The simulation result shows that the SNR of the adaptive subcarrier modulation OFDM radar waveform based on convex optimization is 30.1 dB and the PAPR is 0.8 dB.The loss of SNR is 3.7 dB,but the PAPR is decreased greatly.The good compromise between SNR and PAPR is realized.