Moving Port Prediction: Converting Time-Varying to Static Channels with Fluid Antennas

This paper addresses the mobility problem with the assistance of fluid antenna (FA) on the user equipment (UE) side. We propose a matrix pencil-based moving port (MPMP) prediction method, which may transform the time-varying channel to a static channel by timely sliding the liquid. Different from the existing channel prediction method, we design a moving port selection method, which is the first attempt to transform the channel prediction to the port prediction by exploiting the movability of FA. In the performance analysis, we derive the asymptotical lower and upper bounds of the prediction error for a multipath channel, when the number of base station (BS) antennas and the port density of the FA are large enough. When the UEs move at a speed of 120 km/h, simulation results show that, with the assistance of FA, our proposed MPMP method performs better than the existing channel prediction method.