Using the frequency-division duplex long-term evolution (LTE)-based multistatic passive radar system for unmanned aerial vehicle (UAV) detection is considered. The typical outdoor terrestrial LTE eNodeBs and the broadband direct air-to-ground communications network eNodeBs are used to cover the UAVs at the low altitude and at the medium-high altitude, respectively. The bistatic range measurements are obtained from multiple eNodeBs, and the hyperbolic positioning technique is used for target localisation. Since the existing LTE downlink signals are more suitable for the transmission of the communication data rather than target detection, a new LTE downlink signal feature termed as target localisation reference signals (TLRS) is designed exclusively for the passive radar application using the Costas frequency coding and the P4 phase coding. Compared with the existing LTE downlink signal features, the TLRS have better waveform properties and could potentially provide much higher target detection accuracy. Meanwhile, the TLRS occupy only 0.266% LTE downlink time–frequency resources within a time frame of 1 s when the bandwidth is 10 MHz and have no negative impact on the normal LTE downlink data transmission.

中文翻译：

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基于LTE的无人机无源多雷达系统

考虑使用基于频分双工长期演进（LTE）的多静态无源雷达系统进行无人机（UAV）检测。典型的室外地面LTE eNodeB和宽带直接空对地通信网络eNodeB用于分别覆盖低海拔和中高海拔的无人机。从多个eNodeB获得双基地距离测量值，并将双曲线定位技术用于目标定位。由于现有的LTE下行链路信号更适合于通信数据的传输而不是目标检测，因此，被称为目标定位参考信号（TLRS）的新LTE下行链路信号特征是专门为使用Costas频率编码和无源雷达应用而设计的。 P4相位编码。与现有的LTE下行链路信号特征相比，TLRS具有更好的波形特性，并可能提供更高的目标检测精度。同时，当带宽为10 MHz时，TLRS在1 s的时间范围内仅占用0.266％的LTE下行链路时频资源，并且对正常的LTE下行链路数据传输没有负面影响。