Doppler shift compensation techniques for RIS-assisted millimeter-wave wireless communications in high-speed railways
MA Bolin
ZHEN Jina
ZHANG Chang
SHEN Lingfeng
YANG Jingya
WANG Ning
Abstract：In reconfigurable intelligent surface(RIS)-assisted millimeter-wave(mmWave)wireless communication systems for high-speed railways,the RIS-assisted Doppler shift compensation tech-niques are investigated to address the frequency shift caused by the Doppler effect of electromagnetic waves in highly dynamic,high-speed environments.First,based on a time-varying 3D Saleh-Valenzuela mm Wave channel model,an expression for the Doppler shift is derived,and an optimal RIS phase shift matrix is designed with the objective of compensating for the Doppler shift in the cas-caded transmission link.Next,considering errors in vehicle speed estimation,the speed estimation er-ror and its Probability Density Function(PDF)are analyzed,from which the residual Doppler error is computed,and its impact on the study is discussed.Finally,to evaluate the performance of the com-pensated system,analytical expressions for Spectral Efficiency(SE)and outage probability(OP)are derived,and simulation experiments are conducted to validate the effectiveness of the approach.Simu-lation results show that minimizing the Doppler shift,instead of maximizing received power,can com-pletely eliminate the Doppler shift.When the number of RIS is 322 and the base station antenna height is 50 m,the SE increases by 5.87 bit/(s·Hz)when the train approaches the RIS.Additionally,when the height of the base station antenna is 30 m,50 m and 70 m,the OP varies between 5× 10-3 and 6×10-3.
Keywords：reconfigurable intelligent surfacehigh-speed railway mm Wave communicationsDoppler shift compensationphase shift matrix optimization
Publication Date：2025-06-30
Online Publishing Date：2025-08-21(First online date of this platform, not the publication date of the document)
Pages：10( 147-156 )