OFDM 雷达通信一体化的同频干扰抑制技术

Co-channel Interference Suppression for OFDM IntegratedRadar and Communication

雷达通信一体化系统(Integrated Radar and Communication System,IRCS)可提升设备的可用性、可靠性和电磁兼容性,已成为雷达和通信交叉领域的研究热点。正交频分复用(Orthogonal Frequency Division Multiplexing,OFDM)具有高信息传输性能,且其模糊函数具有低旁瓣特性,在IRCS中得到广泛关注。在OFDM-IRCS中,组网时同频干扰严重影响雷达探测性能。针对这一问题,从信干比(Signal to Interference Ratio,SIR)分析了IRCS同频干扰特性,推导了回波信号SIR的表达式。然后,结合OFDM中交织多址(Interleave Division Multiple Access,IDMA)和干扰重构的思想,提出了基于OFDM-IDMA的IRCS同频干扰抑制算法。所提算法通过不同的交织方式区分不同IRCS节点的信号,同时利用基于干扰重构的干扰消除算法实现干扰抑制。仿真结果表明,所提算法有效地抑制了IRCS同频干扰,实现了同频干扰环境下雷达目标探测性能提升。

The integrated radar and communication system(IRCS)can improve the availability,reliability and electromag⁃netic compatibility of multi-system platforms.Therefore,IRCS has become a hot research topic in the cross field of radar and communication.The orthogonal frequency division multiplexing(OFDM)signal has good communication capability and its ambiguity function has low sidelobes,thus it has received extensive attention in IRCS.In OFDM-IRCS,the cochannel interference seriously affects the performance of radar detection during networking.Aiming to address this prob⁃lem,the co-channel interference for IRCS is analyzed from the aspects of signal-to-interference ratio(SIR)and the SIR is derived.Then,combining the interleave division multiple access and interference reconstruction in OFDM,a co-channel interference suppression algorithm for IRCS based on OFDM-IDMA is proposed.The proposed algorithm distinguishes the signals of different integrated nodes via different interleaving patterns,and realizes the interference suppression through the interference cancellation algorithm based on interference reconstruction.The simulation results show that the proposed algorithm effectively suppresses IRCS co-channel interference and improves the detection performance.