A New Joint subcarrier, bit and power allocation scheme for multiuser ofdm systems

In this paper, a new scheme for adaptive subcarrier, bit and power allocation for downlink transmission of multiuser OFDM systems is presented. Assuming that base stations know the channel gains of all subcarriers of all the users, the proposed loading algorithm tries to minimize the required transmit power while satisfying the rate requirement and data error constraint of each user. The novel algorithm determines the subcarrier, bit and power allocation in two steps with using the algorithm, introduced recently. As demonstrated in the simulation results, the proposed algorithm outperforms all prior sub-optimum schemes, while offering comparable computational complexity.