论文标题
具有可重构智能表面的毫米波通信：性能分析和优化
Millimeter Wave Communications With Reconfigurable Intelligent Surface: Performance Analysis and Optimization
论文作者
论文摘要
可重新配置的智能表面（RIS）可以创建有利的多径，以建立在毫米波（MMWave）通信中有用的牢固链接。虽然先前的作品使用雷利（Rayleigh）或里奇亚（Rician）褪色，但我们使用波动的两射线（FTR）分布来模拟MMWave频率的小规模褪色。首先，我们获得了独立FTR随机变量（RV）和FTR RVS产物总和的统计特征。对于RIS AID和放大（AF）继电器系统，我们得出了精确的端到端信噪比（SNR）表达式。为了最大化端到端SNR，我们提出了一种新颖而简单的方法来获得RIS元素的最佳相移。还提出了AF继电器系统的最佳功率分配方案。此外，我们评估了重要的性能指标，包括中断概率和平均位误差概率。为了验证我们的分析结果的准确性，随后进行了蒙特卡洛模拟，以提供有趣的见解。发现RIS辅助系统可以实现与发射功率低的AF继电器系统相同的性能。更有趣的是，随着频道条件的改善，RIS ADED系统可以胜过具有相同传输功率的AF继电器系统，而反射元素数量较小。
Reconfigurable Intelligent Surface (RIS) can create favorable multipath to establish strong links that are useful in millimeter wave (mmWave) communications. While previous works used Rayleigh or Rician fading, we use the fluctuating two-ray (FTR) distribution to model the small-scale fading in mmWave frequency. First, we obtain the statistical characterizations of the product of independent FTR random variables (RVs) and the sum of product of FTR RVs. For the RIS-aided and amplify-and-forward (AF) relay systems, we derive exact end-to-end signal-to-noise ratio (SNR) expressions. To maximize the end-to-end SNR, we propose a novel and simple way to obtain the optimal phase shifts at the RIS elements. The optimal power allocation scheme for the AF relay system is also proposed. Furthermore, we evaluate important performance metrics including the outage probability and the average bit error probability. To validate the accuracy of our analytical results, Monte-Carlo simulations are subsequently conducted to provide interesting insights. It is found that the RIS-aided system can achieve the same performance as the AF relay system with low transmit power. More interestingly, as the channel conditions improve, the RIS-aided system can outperform the AF relay system having the same transmit power with a smaller number of reflecting elements.
