近区低旁瓣的OFDM MIMO雷达波形设计

雷达系统在临近目标分辨中存在近区旁瓣过高的问题,导致了弱目标淹没、临近目标回波主旁瓣混叠等现象。针对这一问题,该文提出了一种抑制近区距离旁瓣的正交频分复用(orthogonalfrequency division multiplexing, OFDM) 多输入多输出雷达波形设计方法。首先,构造一组基于相位编码调制的OFDM发射波形集,在此基础上,以极小化极大原理和近区积分旁瓣水平建立目标函数,令发射波形恒模为约束条件;然后,借助发射波形与相位的对应关系,将波形设计转化为无约束优化问题,并利用Broyden-Fletcher-Goldfarb-Shanno算法求解。理论分析和仿真结果表明,该文方法较现有方法具有更好的近区旁瓣抑制特性和更低的运算复杂度。

OFDM MIMO radar waveform design with range sidelobe suppression

Radar systems suffer from raised range sidelobe near the mainlobe in distinguishing adjacent targets, leading to deteriorated detection performance of weak targets and echoesaliasing. To solve this problem, a novel orthogonal frequency division multiplexing (OFDM) multiple input multiple output (MIMO) radar waveform design method with low rangesidelobe near the mainlobe is proposed. First, a bunch of phase coded modulated OFDM waveform is constructed. On this basis, the min-max algorithm and the integrated sidelobelevel are utilized to establish the objective function, and constant modulus is the constraint. Then, the optimization problem is transformed into an unconstrained optimizationproblem based on the relationship between the transmitted waveform and the phase, which is solved by the Broyden-Fletcher-Goldfarb-Shanno algorithm. Simulationresults show that the proposed method has remarkable performance in sidelobe suppression and low computational complexity.