多载频类随机相位编码雷达信号设计与特性分析

A New Multi-Frequency Random Phase Code Radar Signal Designing Method

基于OFDM技术的多频多相编码(multifrequency complementary phase coded,简称MCPC)宽带雷达信号具有控制简单、生成便利和良好的频谱利用率等优点,己成为雷达信号研究领域的重要发展方向和研究热点。用基于改进型Logistic及分段Logistic映射的混沌二相码调制MCPC信号各载频的相位,把混沌信号类随机的性质引入到MCPC信号中,设计出多载频类随机相位编码(multifrequency random-like phase coded,简称MRPC)雷达信号,并对MRPC信号的模糊函数、截获因子、峰均包络功率比(PMEPR)等进行了分析。给出了混沌序列的初值、MRPC信号的载频数及码元个数对PMEPR的影响关系,以便于选择合适的初值、载频数和码元数。仿真结果表明,设计出的新信号既具有MCPC信号的优点,又具有类噪声雷达信号图钉型的模糊函数和良好的抗干扰及低截获(LPI)性能,而且分段Logistic MRPC信号的性能优于改进型Logistic MRPC信号。

We propose what we believe to be a new multi-frequency random phase code （ MRPC） radar signal de-signing method .Its core consists of：（ 1） we use the chaotic biphased code based on the improved Logistic mapping and the piecewise Logistic mapping to modulate the phase of the multi-carrier phase code （ MCPC） radar signal;（2） we introduce the quasi-random properties of a chaotic signal into the MCPC radar signal and design the MRPC radar signal, whose ambiguity function , interception factor and peak-to-mean envelope power ratio （ PMEPR） is then analyzed;（3） to select the initial value of the chaotic sequence of the MRPC radar signal , the number of its frequency carriers and the number of its phase-modulated bits, we present their influence on the PMEPR .The sim-ulation results, given in Figs.2 through 6, and their analysis show preliminarily that：（1） the new MRPC radar sig-nal we thus designed keeps the strong points of the MCPC radar signal , has the thumbtack function of the quasi-noise radar signal and the excellent anti-jamming and LPI performances;（ 2） the piecewise Logistic MRPC radar signal has a better performance of these kinds than the improved one .