Enhancing Hyper-Connectivity in High-Density LoS Channels for Massive MIMO IoT Systems

In this paper, we focus on enhancing hyper-connectivity in high-density line-of-sight (LoS) channels for Massive MIMO IoT systems, particularly in scenarios involving unmanned aerial vehicles (UAVs) or related consumer IoT devices. In LoS environments, the need for complex channel estimation is significantly reduced, as LoS channels are rather deterministic with zero variance. However, supporting massive consumer IoT deployments over LoS channels presents a challenge due to decreased channel resolvability, making outage probability a critical factor. We investigate the connectivity of massive consumer IoT devices in LoS channels and derive the bounds for spectral efficiency (SE) and energy efficiency (EE) under a specified outage probability. Recognizing the widespread use of multicarrier signals, we apply a clipping peak-to-average power ratio (PAPR) reduction scheme to further improve EE. Based on these derived metrics, we propose a simple yet effective dropping scheme to increase per-user SE and EE, while reducing overall power consumption. Simulation results validate our theoretical analysis and demonstrate the benefits of the proposed approach.