This paper studies the performance of backscatter communications (BC) over emerging fluid antenna (FA) technology. In particular, a single-antenna source sends information to a FA reader through the wireless forward (i.e., source-to-tag) and backscatter (tag-to-reader) channels. For the considered BC, we first derive the cumulative distribution function (CDF) of the equivalent channel at the FA receiver, and then we obtain closed-form expressions of the outage probability (OP) and delay outage rate (DOR) under a correlated Rayleigh distribution. Moreover, in order to gain more insights into the system performance, we present analytical expressions of the OP and DOR at the high SNR regime. Numerical results indicate that considering the FA at the reader can significantly improve the performance of BC in terms of the OP and DOR compared with a single-antenna reader.

翻译：本文研究了新兴流体天线技术下反向散射通信的性能。具体而言，单天线信源通过无线前向（即信源到标签）和反向散射（标签到阅读器）信道向流体天线阅读器发送信息。针对所考虑的反向散射通信，我们首先推导了流体天线接收端等效信道的累积分布函数，然后在相关瑞利分布下获得了中断概率和延迟中断率的闭式表达式。此外，为更深入地理解系统性能，我们给出了高信噪比条件下中断概率和延迟中断率的解析表达式。数值结果表明，与单天线阅读器相比，在阅读器端采用流体天线可显著提升反向散射通信的中断概率和延迟中断率性能。