Backscatter communication is a hot candidate for future IoT systems. It offers the possibility for connectivity with tiny amounts of energy that can be easily obtained from energy harvesting. This is possible as backscatter devices do not actively transmit electromagnetic waves. Instead they only reflect existing electromagnetic waves by changing the antenna load. This fact leads to significant differences compared to classical communication wrt. the modulation schemes and achievable data rates. However, to our best knowledge nobody has so far systematically analyzed the achievable data rates and transmit ranges for different parameter configurations. Within this paper we derive theoretical bounds for backscatter communications based on classical information theory. We then use these bounds to analyze how different parameters - e.g. the distance, the frequency, or the transmit power - affect the achievable data rates. The bounds are derived for mono-static configuration, as well as for bi-static configurations. This allows feasibility analyses for different use-cases that are currently discussed in 3GPP and IEEE 802.

翻译：反向散射通信是未来物联网系统的一个热门候选方案。它实现了仅需从能量获取中轻易获得的极少量能量即可进行连接的可能性。这是因为反向散射设备并不主动发射电磁波，而是仅通过改变天线负载来反射现有电磁波。这一事实导致了与经典通信在调制方案和可达数据速率方面的显著差异。然而，据我们所知，目前尚无人系统地分析不同参数配置下的可达数据速率和传输距离。本文基于经典信息论推导了反向散射通信的理论界限。随后，我们利用这些界限分析了不同参数——例如距离、频率或发射功率——如何影响可达数据速率。这些界限针对单静态配置和双静态配置进行了推导。这为当前在3GPP和IEEE 802中讨论的不同用例提供了可行性分析。