论文标题
使用硬件障碍的智能反射表面系统的能源效率分析
Energy Efficiency Analysis of Intelligent Reflecting Surface System with Hardware Impairments
论文作者
论文摘要
最近，作为移动数据流量的爆炸性增长，无线通信系统的性能在将来需要大大提高。智能反射表面（IRS）可以用作提高无线通信能源效率的一种有希望的方式，并以较少的复杂性和硬件成本。大多数现有研究都认为具有理想硬件的案例，但是，物理收发器和IRS都遭受了不可忽略的硬件障碍，这可能会大大降低系统性能。在本文中，通过考虑硬件损伤，我们将重点放在IRS系统的能源效率分析上。我们的第一个贡献是得出最佳的接收组合和传输波束成形向量。之后，我们表征了渐近通道的能力。借助造成的渐近通道容量和功耗模型，提供了能源效率的分析上限和下限。我们的结果表明，IRS系统可以通过中等数量的天线实现高光谱效率和高能量效率。这一观察结果令人鼓舞，因为在昂贵的高质量天线上无需花很多钱，这与新的通信范式的要求相对应。
Recently, as explosive growth of mobile data traffic, the performance of wireless communication systems requires to be enhanced significantly in future. Intelligent reflecting surface (IRS) can be used as a promising way to improve the energy efficiency of wireless communications with less complexity and hardware cost. Most existing studies consider the cases with ideal hardware, however, both physical transceiver and IRS suffer from non-negligible hardware impairments which may greatly degrade the system performance. In this paper, by taking hardware impairments into consideration, we focus on the energy efficiency analysis of IRS system. Our first contribution is to derive the optimal receive combining and transmit beamforming vectors. After that, we characterize the asymptotic channel capacity. With the derived asymptotic channel capacity and the power consumption model, the analytical upper and lower bounds of energy efficiency are provided. Our results show that an IRS system can achieve both high spectral efficiency and high energy efficiency with moderate number of antennas. This observation is encouraging for that there is no need to cost a lot on expensive high-quality antennas, which corresponds to the requirements of new communication paradigms.
