Movable Antenna System with Movement Delay Consideration: When to Move and Where to Move?

Movable antenna (MA) can be flexibly deployed with high spatial diversity to pursue better channel conditions, which serves as a promising technology for wireless communications. In this paper, we take the antenna moving delay into account, which has not been considered in previous studies, and reveal the trade-off between it and MA position corresponding to disparate channel states. To this end, we meticulously model the achievable throughput for limited transmission block duration, analyze whether MA needs to move with diverse channel conditions, and elaborate an efficient algorithm to optimize MA position via successive convex approximation. Numerical results demonstrate that the proposed algorithm, with excellent stability and adaptability to various transmission block durations and moving region sizes, outperforms the fixed-position antenna system and existing MA algorithm. Additionally, our algorithm is insensitive to antenna moving speed, which makes it possible to reduce the hardware cost of MA systems with low rotational speed motors.