Adaptive Proportional Fair Scheduling in Multihop OFDMA Systems

This paper investigates proportional fairness-oriented scheduling issues for multihop OFDMA systems with multiple relays. Based on the idealized L-hop linear network model, three adaptive proportional fair scheduling (PFS) algorithms, namely optimal PFS, iterative user pairing (IUP) PFS and successive distributed (SD) PFS, are proposed for multihop OFDMA systems. Different with the existing scheme presented in former work, these three algorithms could be applied to OFDMA based multihop (more than two-hop) systems. The optimal PFS is presented as an upper bound in terms of proportional fairness, which involves exponential times of calculations. Thus we propose other two simpler algorithms for practical issue. Given the feature of multihop networks, they try to balance the aggregate data rates of each hop. Simulation results show that both IUP PFS and SD PFS achieves a good tradeoff between performance and complexity.