基于OFDM的无人机雷达通信一体化设计方法
Design Method of Radar-Communication Integration Using OFDM Signals for UAVs
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摘要: 为了最大程度地利用资源和减小电磁干扰,无人机平台的雷达通信一体化设计有着尤为重要的意义。正交频分复用(Orthogonal Frequency Division Multiplexing,OFDM)信号具有较高的频谱利用率、较强的抗干扰性能、易于数字化处理等优点,在雷达通信一体化系统备受关注。然而,OFDM信号在雷达和通信系统中对多普勒频偏较为敏感,针对多普勒频偏引起的子载波间干扰(Inter-Carrier Interference,ICI)问题,本文设计出一种RS-OFDM雷达通信一体化信号,并提出一种ICI抑制的信号处理算法,其中基于多普勒估计和校正实现OFDM的无ICI处理。仿真结果表明:所提方法在目标成像性能上优于传统方法,且对多普勒频偏具有较强的鲁棒性,而且并无明显增加计算复杂度。
Abstract: In order to make full utilization of resources and reduce electromagnetic interference, radar-communication integration (RadCom) on the unmanned aerial vehicle (UAV) platform shows great significance. RadCom system using orthogonal frequency division multiplexing (OFDM) signals has caught much attention of researchers over the past decades, since it has high spectrum efficiency, good antijamming capability and simple digital processing. A fundamental drawback of OFDM signals, both in communication and radar, is its sensitivity to the Doppler effect. To overcome inter-carrier interference (ICI) problem caused the Doppler sensitivity of OFDM, an integrated signal model using repeated symbols OFDM (RS-OFDM) is designed, and an ICI-free processing for OFDM is given based on Doppler estimation and correction. Simulations show that the proposed scheme outperforms the conventional scheme with slightly increased computational complexity, and the robustness of Doppler shift.