The optimization of resource allocation in multi-user orthogonal frequency division multiplexing (OFDM) has been of great concern to the mobile commerce. The major concern is the allocation of subcarrier and power to different users in order to minimize the total transmitted power, consequently increasing the total data rate and improving the performance of the wireless communication system. Multi-user OFDM systems have been in use recently and seem promising for future mobile network applications. This research would mainly focus on modeling and improving the wireless communication system with multi-user OFDM. The proposed optimization techniques for OFDM wireless communication will be conducted in two phases. Phase one is to optimize the subcarrier allocation to mobile hosts, and the second phase is to optimize the power allocation (depends on the number of transmitted bits) in a multi-user OFDM system.