A Mathematical Derivation of a Resource Allocation Matrix for an OFDMA System

In this paper, a resource allocation matrix (RAM) for an orthogonal frequency division multiple access (OFDMA) system is derived to maximize overall data throughput under a strict condition for user fairness. The RAM identifies the most preferable allocation state of OFDMA sub-bands. It is subject to a user fairness condition such that one sub-band is allocated per user during an OFDMA time-slot, allowing each user an equal opportunity to use the sub-bands. The proposed resource allocation scheme using the RAM is evaluated in terms of throughput and user fairness by comparison with the Proportional Fairness (PF) scheme and the Max C/I scheme. Numerical results show that the proposed scheme has much higher throughput under the strict user fairness condition. Even though the PF and Max C/I are given an advantage of ignoring the user fairness condition, the throughput performance of the proposed scheme is quite comparable to that of the PF and Max C/I.