摘要
新兴的智能超表面(Reconfigurable Intelligent Surface,RIS)技术作为6G潜在关键使能技术之一,通过大量的电磁单元智能调控无线信号的反射特性,有望实现对无线传播环境的主动增强与感知,其在角度感知估计方面的应用受到广泛关注。现有文献报道的RIS波达角估计硬件实现工作中,RIS往往采用固定列控或行控的编码方式,无法充分发挥其空间维度自由度,只能进行一维的波达角估计。在此背景下,本论文设计了一套灵活的智能超表面控制平台,实现对每个电磁单元的独立且高速的控制,充分发挥RIS硬件的空间自由度,并在此平台上实现基于RIS的二维波达角实时估计功能。首先,介绍基于RIS的波达角估计系统设计方案,通过对RIS进行高速空时编码调制,使反射信号的谐波分量与入射信号的波达角建立映射关系,在接收端利用反射信号各谐波的幅度和相位信息,对入射信号波达角进行实时估计。随后,基于所提方案设计系统的无线帧结构相关参数,构建基于RIS的二维波达角实时估计原型系统。最后,使用原型系统开展测量实验,在多个测量点位对波达角的方位角和俯仰角分量进行估计与数据记录,实测数据验证了所提方案的可行性。
The emerging technology of reconfigurable intelligent surface(RIS),as one of the potential enabling key technologies for 6G,offers the ability to actively enhance and sense wireless propagation environments by intelligently manipulating the reflection characteristics of wireless signals through a large number of unit cells.Its application in angle perception and estimation has garnered widespread attention.However,in previous studies of hardware implementations of RIS for direction of arrival estimation,the unit cells have usually been controlled in rows or columns,which limits the spatial dimension degrees of freedom,limiting it to one-dimensional direction of arrival estimation.In this context,this paper presents a flexible RIS control platform designed to achieve independent and high-speed control of each unit cell,fully leveraging the spatial dimension of RIS hardware.Building upon this platform,this paper describes the realization of the real-time estimation of two-dimensional direction of arrival.First,we introduce the scheme for the RIS-based direction of arrival estimation system.By applying high-speed space-time coding modulation to the RIS,a mapping relationship between the harmonic components of the reflected signal and the direction of arrival of the incident signal is established.At the receiver,the amplitude and phase information of the harmonic components of the reflected signal are utilized to estimate the direction of arrival of the incident signal in real time.Next,based on the proposed scheme,we designed the wireless frame structure and key parameters of the system,constructing a prototype of the RIS-based two-dimensional direction of arrival estimation system.Finally,using the prototype,measurement experiments were conducted within the range of azimuth angle from−50 to 50 degrees and elevation angles from−30 to 40 degrees.Thirty-two measurement points were selected to estimate and record the azimuth and elevation angle of the incident signal.By analyzing the experimental data,it was found
作者
徐奕凡
周群焰
孟声国
李泽
唐万恺
戴俊彦
程强
金石
XU Yifan;ZHOU Qunyan;MENG Shengguo;LI Ze;TANG Wankai;DAI Junyan;CHENG Qiang;JIN Shi(National Mobile Communications Research Laboratory,Southeast University,Nanjing,Jiangsu 210096,China;State Key Laboratory of Millimeter Waves,Southeast University,Nanjing,Jiangsu 210096,China)
出处
《信号处理》
CSCD
北大核心
2024年第8期1469-1479,共11页
Journal of Signal Processing
基金
国家重点研发计划(2023YFB3811505,2023YFB3811502)
国家自然科学基金(62201138,U22A2002,62231009)
江苏省前沿引领技术基础研究专项(BK20212002)
江苏省自然科学基金(BK20220809)。
关键词
智能超表面
空时编码
波达角估计
原型实现
reconfigurable intelligent surface
space-time coding
direction of arrival estimation
prototyping
