基于失配处理的OFDM雷达通信一体化共享信号旁瓣抑制技术

现代电子信息系统的应用领域在不断拓展,导致雷达和通信的带宽需求日益增长、工作频段不断重合,引发了电磁频谱竞争激烈、电磁干扰严重和电磁资源利用率低下等诸多问题。鉴于此,国内外专家学者提出了雷达通信一体化共享信号的解决思路。其中,OFDM信号被视为最有潜力的一体化共享信号。然而,受通信信息的高随机性和OFDM帧结构的周期性影响,该信号的雷达点扩展函数旁瓣较高,且存在大量伪峰。为此,本文围绕OFDM雷达通信一体化共享信号,从模糊函数的角度剖析了该信号的本质缺陷,并提出了一种利用失配滤波将旁瓣和伪峰外推至雷达观测窗口外的处理算法。通过理论分析和仿真可知,该算法可使OFDM一体化共享信号兼备高速通信和高性能雷达探测性能。 

A Novel Side-Lobe Suppression Technology for the OFDM-Based Joint Radar and Communication Waveforms Using the Mismatching

With the continuously expanding of the advanced electronic information system applications, the bandwidth requirements of radar and communication are increasing, and the working frequency bands are constantly overlapping. To this end, an important issue arises with regard to the competition of the spectrum resources. Some papers have proposed the concept of the joint waveform to share the spectrum. Following this concept, the OFDM waveforms have arouse as the potential solutions. However, due to impact of the high randomness and the periodic characteristics of OFDM-based wireless communication signals, the point spread function for the radar sensing contains high side lobes and numerous fake peaks. In this paper, the intrinsic drawbacks of the OFDM-based joint radar and communication waveforms are analyzed from the perspective of ambiguity function. Following which, a novel side-lobe suppression algorithm using the mismatching is proposed by moving the ambiguous energy outside the radar observation window. With the algorithm, it becomes possible to realize the wireless communication and the radar sensing in a shared time-frequency plane. Theoretical analysis is validated by simulations.