Movable-Antenna Enabled Cell-Free Networks

In this paper, we investigate the utilization of movable antennas (MAs) in cell-free networks to reduce transmit power consumption. Different from conventional networks with fixed-position antennas (FPAs), the proposed MA-enabled cell-free network flexibly adjusts the antenna positions in a given finite area. As such, the channels between multiple access points (APs) and user equipments (UEs) can be reconfigured to create more favorable channel conditions. To minimize the maximum transmit power of APs in the considered network, a non-convex problem is formulated by jointly optimizing the transmit beamforming and MA positions. Then, we propose a dynamic neighborhood pruning particle swarm optimization (DNPPSO) algorithm to solve this problem efficiently. Simulation results show that the proposed scheme with MAs can significantly reduce the transmit power consumption in cell-free networks compared to benchmarks with FPAs by exploiting the degrees of freedom (DoFs) in antenna position optimization.