Efficient subcarrier-power allocation scheme for multiuser OFDM systems

Multiuser Orthogonal Frequency Division Multiplexing (MU-OFDM) is a promising technique for achieving high total capacities in wireless communication systems. The key issue of MU-OFDM is the allocation of resources (subcarriers and power) to users sharing the channel. In this paper, a subcarrier-power allocation algorithm is proposed, to enhance the total system capacity in the MU-OFDM system. Specifically, a proposed subcarrier allocation algorithm is presented, in order to avoid assigning users the subcarriers with worst channel gain. After the subcarrier-allocation, a subcarrier gain based power allocation (SGPA) algorithm is employed for power and bit loading. It is shown through simulation that the proposed subcarrier-power allocation algorithm can achieve high total system capacity and good fairness in allocating the resources among the users with slightly high computational complexity comparing with the existing algorithms.