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热门候选技术。由于反向散射设备不主动发射电磁波，仅通过改变天线负载来反射现有电磁波，因此可以从能量采集中轻松获取微量能量，实现低功耗连接。这一特性导致其在调制方案和可达数据速率方面与传统通信存在显著差异。然而，据我们所知，此前尚未有研究系统性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，并利用这些界限分析距离、频率、发射功率等参数对可达数据速率的影响。这些界限分别针对单站配置和双站配置进行推导，从而为当前3GPP和IEEE 802中讨论的不同用例提供可行性分析。