A Novel Socially-Differentiated Handover Scheme for UE-Centric Cell-Free Massive MIMO

While UE-centric cell-free massive MIMO (CF-mMIMO) provides superior throughput performance against traditional network-centric distributed MIMO in static networks, it loses its advantage under mobility due to the effects of channel aging and handover delay overheads. To preserve the ability of UE-centric CF-mMIMO to offer uniformly high network-wide throughput under mobility, we propose a socially-differentiated handover scheme. Our scheme differentiates the handover policy for different UEs by their performance level relative to the rest of the network, thus reducing the handover rate while maintaining the necessary handovers for the most "in-need" UEs. Our results show that our scheme achieves high mobility-aware throughput performance for UE-centric CF-mMIMO and significantly outperforms both the existing handover schemes and network-centric MIMO, under both channel aging and handover delay cost.