Local link information based data scheduling in OFDMA wireless networks

The link time-varying characteristics caused by Reyleigh fading and co-channel interference result in a bottleneck during the process of data scheduling in wireless networks. This paper present an analytical model for formulating the problem of subcarrier allocation and bit loading as a constrained joint-layer resource optimization in OFDMA-based wireless networks. we propose a distributed scheduling algorithm (DSA) which chooses subcarriers randomly based on channel condition of local subcarriers while adopting a power control mechanism to limit co-channel interference for maximizing subcarrier reuse among different links. To achieve better global fairness, depending on DSA, we also present a global power control scheduling algorithm (GPCSA) which can enhance transmission rate over some local links by adjusting power allocation according to the difference between the average C/I of local links and the system link protection ratio. We demonstrate the analysis accuracy and the characteristics improvements both in efficiency and fairness by extensive simulation results.