Resource Unit Allocation in Coordinated OFDMA Multi-User Wi-Fi Systems

The scheduling of resource units (RUs) in a multi-AP coordination network is considered vital for high spectrum efficiency and effective interference mitigation in future Wi-Fi Networks. In this paper, we propose a RU allocation scheme to maximize the long-term average network throughput of STAs in a multi-AP coordinated Wi-Fi network within a joint coordinated orthogonal frequency-division multiple access (C-OFDMA) and coordinated special reuse (CSR) framework. The proposed scheme ensures that the average rates satisfy the STAs’ quality of service (QoS) requirements and the interference in the overlapping basic service sets (OBSSs) is efficiently managed. The original RU allocation problem is formulated as binary integer programming, which is an NP hard. To address this, a heuristic graph coloring model is introduced for RU allocation in OBSSs, where the Sharing-AP allocates RUs with weighted max-min (WMM)-based graph coloring to overlapping STAs while simultaneously assigning RUs to its own STAs within the same frequency band using the WMM algorithm. Simulation results demonstrate that the proposed RU scheduling algorithm enhances overall mean network throughput by 30%. The simplicity and low computational complexity of the proposed algorithm confirm its effectiveness and practicality for implementation.