用于SAR与通信一体化系统的滤波器组多载波波形

Filter Bank Multicarrier Waveform Used for Integrated SAR and Communication Systems

合成孔径雷达(SAR)与通信一体化可提升SAR的信息交互能力,实现探测数据实时传输,提升系统整体性能。一体化平台在工作过程中,将引入多普勒偏移和多径效应,这使得广泛研究的正交频分复用(OFDM)一体化波形的正交性无法保持,成像与通信性能受限。该文提出利用滤波器组多载波(FBMC)波形实现SAR与通信一体化,一方面,FBMC波形对子载波间的正交性要求低,可以对抗多普勒与多径效应,另一方面,FBMC波形不采用循环前缀(CP),因此可以避免出现虚假目标,提升了频谱利用率。该文分析了FBMC波形的一体化性能,针对一体化系统中的多径效应与多普勒偏移对FBMC波形的影响展开了研究,并针对大频偏的情况提出了适用于FBMC一体化波形的多普勒补偿算法。基于FBMC的SAR与通信一体化波形在宽测绘带SAR与通信一体化系统中有更好的性能,仿真试验验证了该结论。

The integrated Synthetic Aperture Radar （SAR） and Communication system can improve the networking capabilities of SAR, realize the real-time transmission of detection data, and improve the overall performance of the system. In the working process of the integrated platform, Doppler shift and multipath effects will be introduced, which make the orthogonality of the widely studied Orthogonal Frequency Division Multiplexing （OFDM） integrated waveforms unable to be maintained, and the imaging and communication performance is impaired. In this paper, the Filter Bank Multicarrier （FBMC） waveform used for the integrated SAR and communication systems is proposed. On the one hand FBMC waveforms require low orthogonalitybetween subcarriers, which can counter Doppler and multipath effects. On the other hand, FBMC waveforms do not use Cyclic Prefix （CP）, so the false targets can be avoided and spectral efficiency can be improved. This paper analyzes the integrated performance of FBMC waveforms, studies the effects of multipath and Doppler shift on FBMC waveforms in the integrated system, and proposes a Doppler compensation algorithm for integrated FBMC waveform with large frequency shift. According to the above analysis, the FBMC waveform has better performance in the wide swath SAR and communication integration system. Simulation results verify the conclusion.