Applying Generalized Cμ-rule Scheduling for Resource Allocation in OFDMA Systems

We study the performance of generalized cμ-rule implementation in OFDMA systems, namely bit-based subcarrier allocation and packet-based subchannel allocation. While cμ-rule is asymptotically optimum in continuous-time server allocation, it needs to be adjusted when applied to discrete-time server allocation in OFDMA systems. Bit-based allocation considers the allocation through bit-based connectivity. Resource wastage is prevented by greedy reassignment in low traffic regime. Packet-based allocation adopts cμ-rule and allocates the servers through multiple-packet rates. The allocation is ordered from the server with lowest connectivity to the server with highest connectivity. Simulation results show that bit-based allocation outperforms packet-based allocation in queue length minimization for small number of users. With increasing number of users, the performance difference becomes smaller and at the certain limit, the packet-based allocation performs better. Furthermore, the packet-based allocation might be better in practical realization due to the lower complexity.