正交信号MIMO雷达动态范围与弱目标检测性能分析

正交信号MIMO雷达各阵元发射相互正交的信号波形，多个信号波形在空间不能叠加形成高增益的窄波束，经目标反射回来的回波信号的动态范围较传统相控阵雷达有所降低，这将有利于改善对强杂波中的弱目标信号的检测性能。动态范围往往取决于杂波功率，本文分析了基于OFDM-LFM信号的MIMO雷达的信号功率问题，并提出利用优化的随机相位来降低信号瞬时功率，从而改善回波信号的动态范围。仿真比较了在接收机动态范围一定的条件下，MIMO雷达相对于传统相控阵雷达在弱目标检测性能方面的改善。 

Analysis of the dynamic range and the detection performance of weak target for orthogonal waveform MIMO radar

Each of the elements in orthogonal MIMO radar transmits orthogonal waveform. The various emitted signals can not be combined to form a focused beam. The dynamic range of returned signal reflected by a target will be smaller than that of the traditional phased array radar, and so it is advantaged for MIMO radar to detect weak targets in strong clutter. The dynamic range is mainly dependent on the clutter power. In this paper, the signal power of MIMO radar using OFDM-LFM waveform is analyzed, and optimized random initial phases are utilized to reduce the signal instant power and to modify the dynamic range of returned signal. The improvement of the performance of detecting weak target is showed through simulation by comparing MIMO radar to traditional phased array radar.