In this work, we exploit the radar clutter (i.e., the ensemble of echoes generated by the terrain and/or the surrounding objects in response to the signal emitted by a radar transmitter) as a carrier signal to enable an ambient backscatter communication from a source (tag) to a destination (reader). The proposed idea relies on the fact that, since the radar excitation is periodic, the radar clutter is itself periodic over time scales shorter than the coherence time of the environment. Upon deriving a convenient signal model, we propose two encoding/decoding schemes that do not require any coordination with the radar transmitter or knowledge of the radar waveform. Different tradeoffs in terms of transmission rate and error probability can be obtained upon changing the control signal driving the tag switch or the adopted encoding rule; also, multiple tags can be accommodated with either a sourced or an unsourced multiple access strategy. Some illustrative examples are provided.

翻译：本文利用雷达杂波（即雷达发射机信号经地形及周围物体反射产生的回波集合）作为载波信号，实现从源端（标签）到目的地（读取器）的环境反向散射通信。该思想基于以下事实：由于雷达激励具有周期性，雷达杂波在短于环境相干时间的时间尺度上本身也是周期性的。在建立便捷信号模型后，我们提出两种无需与雷达发射机协调或已知雷达波形的编解码方案。通过改变驱动标签开关的控制信号或所采用的编码规则，可获得传输速率与误码率的不同折中；同时，可基于有源或无源多址接入策略支持多个标签。文中给出了若干示例。