Fig. 5: Multiuser MISO communication scenario and simulation results based on ray-tracing.

a Simulation scenario; b Simulation results. (Simulation setup: The single-antenna users are randomly distributed within an urban area of size 220 m × 410 m at Clementi, Singapore. Each channel realization is obtained via ray-tracing based on the randomly generated user locations within the target area. The dense uniform planar array (UPA) and sparse UPA schemes adopt 4 × 4 FPAs with inter-antenna spacing given by λ/2 and 2λ, respectively, where λ denotes the carrier wavelength and the carrier frequency is 5 GHz. For MA systems, the BS is equipped with 16 MAs with the size of the two-dimensional (2D) antenna moving region given by 8λ × 8λ, where the antenna positions are optimized based on gradient ascent for maximizing the ergodic sum rate of users⁶². Each RA has 4 candidate radiation patterns¹⁷, with the optimal one selected via alternate refinement for each antenna through exhaustive search. For all schemes, zero-forcing (ZF) beamforming is adopted with the optimal power allocation determined by water-filling.)