A Probabilistic QoS-Aware User Association in Cell-Free Massive MIMO for Industry 4.0
20 October 2023
Industry 4.0 requires wireless solutions that meet various cyber-physical systems' high reliability and low latency requirements and serve many industrial sensors and actuators. A new paradigm of physical layer technology, cell-free massive multiple input multiple output (MIMO), exploiting both massive MIMO gains and cell-free properties is expected to play a crucial role in addressing such challenging communication requirements. However, finding an optimal user association to satisfy quality of service (QoS) requirements is critical. In this article, we propose a novel centralized probabilistic user association algorithm to identify and maximize the number of served users without relying on short-term channel state information to satisfy the QoS requirements. Simulation results prove the effectiveness and adaptability of the proposed algorithm in terms of achievable spectral efficiency as well as maximizing the number of satisfied users for varying requirements and factory sizes.