智能反射面辅助的环境反向散射通信系统信道估计算法研究  

Channel Estimation for Intelligent Reflecting Surface Assisted Ambient Backscatter Communication Systems

作　　者：徐勇军[1] 邱友静 张海波[1] XU Yongjun;QIU Youjing;ZHANG Haibo(School of Communication and Information Engineering,Chongqing University of Posts and Telecommunications,Chongqing 400065,China)

机构地区：[1]重庆邮电大学通信与信息工程学院,重庆400065

出　　处：《电子与信息学报》2025年第1期75-83,共9页Journal of Electronics & Information Technology

基　　金：国家自然科学基金(62271094,U23A20279);重庆市自然科学基金重点项目(CSTB2022NSCQ-LZX0009,CSTB2023NSCQ-LZX0079);重庆市教委科技重点项目(KJZD-K202200601)。

摘　　要：环境反向散射通信(AmBC)是一种新型的低功耗通信技术,它能利用周围环境中的射频(RF)信号源实现无源信息传输,但由于其存在双重衰落、障碍物阻挡等问题,导致反射链路信号强度弱。为此,该文将智能反射面(IRS)引入到AmBC系统中用以增强反射链路增益。然而,IRS与标签均为无源器件使得信道估计极具挑战性。为此,该文提出了一种IRS辅助的AmBC系统信道估计方案。首先,将信道分解为多个子信道,其中,反射链路的每个子信道对应一个IRS反射单元。然后,将最小二乘(LS)法作为估计准则,以最小化均方误差(MSE)为目标,探索了IRS反射模式与信道估计的联合设计。仿真结果表明,该信道估计方案具有良好的估计性能。Objective Ambient Backscatter Communication(AmBC)is an emerging,low-power,low-cost communication technology that utilizes ambient Radio Frequency(RF)signals for passive information transmission.It has demonstrated significant potential for various wireless applications.However,in AmBC systems,the reflected signals are often severely weakened due to double fading effects and signal obstruction from environmental obstacles.This results in a substantial reduction in signal strength,limiting both communication range and overall system performance.To address these challenges,Intelligent Reflecting Surface(IRS)technology has been integrated into AmBC systems.IRS can enhance reflection link gain by precisely controlling reflected signals,thereby improving system performance.However,the passive nature of both the IRS and tags makes accurate channel estimation a critical challenge.This study proposes an efficient channel estimation algorithm for IRS-assisted AmBC systems,aiming to provide theoretical support for optimizing system performance and explore the feasibility of achieving high-precision channel estimation in complex environments—key to the practical implementation of this technology.Methods This study develops a general IRS-assisted AmBC system model,where the system channel is divided into multiple subchannels,each corresponding to a specific IRS reflection element.To minimize the Mean Squared Error(MSE)in channel estimation,the Least Squares(LS)method is used as the estimation criterion.The joint optimization problem for channel estimation is explored by integrating various IRS reflection modes,including ON/OFF,Discrete Fourier Transform(DFT),and Hadamard modes.The communication channel is assumed to follow a Rayleigh fading distribution,with noise modeled as zero-mean Gaussian.Pilot signals are modulated using Quadrature Phase Shift Keying(QPSK).To thoroughly evaluate the performance of channel estimation,1000 Monte Carlo simulations are conducted,with MSE and the Cramer-Rao Lower Bound(CRLB)serving as perf

关 键 词：环境反向散射通信 智能反射面 信道估计 

分 类 号：TN929.5[电子电信—通信与信息系统]