Exploiting Multiuser Diversity in OFDMA Wireless Mesh Networks by Fractional Spatial Reuse

We consider subcarrier assignment and power allocation in OFDMA wireless mesh networks. Traditional full spatial reuse increases bandwidth efficiency but ignores multiuser diversity in the multi-hop network. Our method enables fractional spatial reuse with which multiuser diversity can also be exploited. The original optimization problem is decomposed into three tractable subproblems. First, subcarrier numbers on each link are decided according to end-to-end requirement and node power constraint. Then a novel link grouping method is proposed to utilize fractional spatial reuse in the network. Finally, a tabu-based subcarrier assignment algorithms is designed to assign subcarriers to groups to exploit multiuser diversity. Performance is evaluated under various network sizes to investigate the impact of spatial reuse and simulation results show our proposed scheme achieves multiuser diversity in spatial reuse scenarios.