Optimizing user throughput with the consideration of multiple access interference in the OFDMA uplink

In the uplink of OFDMA systems, Multiple Access Interference (MAI) can cause considerable reduction in the throughputs of the User Terminals (UTs). It is well known that applying optimal resource allocation is an efficient means to mitigate MAI, thereby improving UTs' throughputs. In this paper, we show the importance of the consideration of MAI in the resource allocation optimization. To do that we develop a new optimization model based on a solvable minimization of maximum of normalized MAI, which considers MAI and offers suboptimal resource allocation subject to the desired throughput goal. We show that the proposed optimization model improves significantly the minimum UT throughput by approximately 32%. Further, we numerically evaluate and analyze the spread of the resource allocation. As a result of the analysis, we show that, counterintuitively, spreading resource allocation can mitigate MAI and improve user throughputs.