This letter presents a detailed performance analysis of the intelligent reflecting surface (IRS) aided single-input single-output communication systems, taking into account of the direct link between the transmitter and receiver. A closed-form upper bound is derived for the ergodic capacity, and an accurate approximation is obtained for the outage probability. In addition, simplified expressions are presented in the asymptotic regime. Numerical results are provided to validate the correctness of the theoretical analysis. It is found that increasing the number of reflecting elements can significantly boost the ergodic capacity and outage probability performance, and a strong line-of-sight component is also beneficial. In addition, it is desirable to deploy the IRS close to the transmitter or receiver, rather than in the middle.

中文翻译：

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智能反射面辅助通信系统性能分析

这封信提供了智能反射面 (IRS) 辅助单输入单输出通信系统的详细性能分析，同时考虑了发射器和接收器之间的直接链接。推导出遍历容量的封闭形式上限，并获得中断概率的准确近似值。此外，在渐近机制中呈现了简化表达式。数值结果验证了理论分析的正确性。发现增加反射元件的数量可以显着提升遍历容量和中断概率性能，并且强大的视线分量也有好处。此外，最好将 IRS 部署在靠近发射器或接收器的地方，而不是在中间。