Unmanned aerial vehicles (UAVs) can be integrated into wireless sensor networks (WSNs) for smart city applications in several ways. Among them, a UAV can be employed as a relay in a "store-carry and forward" fashion by uploading data from ground sensors and metering devices and, then, downloading it to a central unit. However, both the uploading and downloading phases can be prone to potential threats and attacks. As a legacy from traditional wireless networks, the jamming attack is still one of the major and serious threats to UAV-aided communications, especially when also the jammer is mobile, e.g., it is mounted on a UAV or inside a terrestrial vehicle. In this paper, we investigate anti-jamming communications for UAV-aided WSNs operating over doubly-selective channels in the downloading phase. In such a scenario, the signals transmitted by the UAV and the malicious mobile jammer undergo both time dispersion due to multipath propagation effects and frequency dispersion caused by their mobility. To suppress high-power jamming signals, we propose a blind physical-layer technique that jointly detects the UAV and jammer symbols through serial disturbance cancellation based on symbol-level post-sorting of the detector output. Amplitudes, phases, time delays, and Doppler shifts - required to implement the proposed detection strategy - are blindly estimated from data through the use of algorithms that exploit the almost-cyclostationarity properties of the received signal and the detailed structure of multicarrier modulation format. Simulation results corroborate the anti-jamming capabilities of the proposed method, for different mobility scenarios of the jammer.
翻译:无人驾驶航空飞行器(UAVs)可以通过多种方式被纳入智能城市应用的无线传感器网络(WSNs)中。其中,无人驾驶航空飞行器可以通过上传地面传感器和计量装置的数据,然后将数据下载到中央单位。然而,上载和下载阶段都可能面临潜在的威胁和攻击。由于传统无线网络遗留下来的遗产,干扰袭击仍然是对UAV辅助通信的主要和严重威胁之一,特别是当干扰器是移动的,例如,它可以安装在UAV或地面车辆中,作为“储存和前方”式的中继器。在本文中,我们调查UAVAV辅助的WSNS在下载过程中以加倍选择性渠道运行的反干扰通信。在这种情景中,UAV和恶意移动干扰器传递的信号会由于其移动造成的多重传播效应和频率变异。为了抑制高强度阻力信号,我们建议使用一个双向的信号,即静压的信号,即通过测算系统测算系统测算系统测算的测算系统,通过测算系统测算系统测算系统测算系统测算系统测算,通过测算系统测算系统测算系统测算测算系统测算系统测算系统测算测算测算的测算测算的测算测算的测算的测算的测算系统。