可重构智能表面通信系统的离散相位误差分析

Discrete phase error analysis of reconfigurable intelligent surface-assisted communication system

针对可重构智能表面(RIS)实际部署中理想连续相位难实现,造成的性能下降问题,提出一种包含离散相位误差的RIS辅助通信系统。基于三维统计型信道模型,推导该系统遍历容量的近似值表达式。对比理想连续相位的系统后,推导不同相位量化水平的容量损失。仿真验证了遍历容量近似值与蒙特卡罗仿真值能够匹配,同时表明使用一定精度(本文是3至4比特)的相位离散化方案足以逼近连续相位系统的遍历容量。这为RIS的低硬件成本和复杂度的实际应用提供了理论支撑。

To solve the performance degradation due to limited precision configuration of the reflecting phases,a reconfigurable intelligent surface(RIS)assisted system with discrete phases was investigated.Based on the three-dimensional statistical channel model,the approximate closed-form expression of the ergodic capacity was derived.Compared with the ideal continuous phase,the proposed system capacity loss expressions at different quantization degrees were obtained.Monte Carlo simulation results can match the proposed approximated capacity.Simulation is also shown that the ergodic capacity of discrete phase system with certain precision(about 3-4 bits in this paper)can be very close to that of continuous phase system,which can provide theoretical support for reducing hardware cost and complexity in practical.