We investigate in this paper the resource allocation problem in an uplink OFDMA multiuser system. We focus on the Proportional Fairness approach which aims to maximize the system throughput and while ensuring fairness between users. In this paper, we propose a Weighted Proportional Fair algorithm for resource allocation that introduces priorities between users to better exploit good channel conditions in the cell center. We also perform a theoretical analysis to compare both standard and weighted proportional fair algorithms. Simulation results, compared to existing algorithms, show that the proposed algorithm approaches the max sum rate upper bound but still maintains sufficient fairness between users.