Doppler Shift and Channel Estimation for Intelligent Transparent Surface Assisted Communication Systems on High-Speed Railways

The critical distinction between the emerging intelligent transparent surface (ITS) and reflection (IRS) is that incident signals can penetrate ITS instead of being reflected, which enables to combat severe signal penetration loss for high-speed railway (HSR) wireless communications. This paper thus investigates channel estimation problem an ITS-assisted HSR network where embedded into carriage window. We first formulate channels as functions physical parameters, transform a parameter recovery problem. Next, we design two pilot blocks within each frame develop serial low-complexity algorithm. Specifically, estimates are initially obtained, estimate further expressed sum its perfectly known value error. By leveraging relationship blocks, recover Doppler shifts from estimates, based on acquire other parameters. Moreover, Cramer-Rao lower bound (CRLB) derived performance benchmark. Finally, provide numerical results establish effectiveness our proposed estimators.