An Efficient Joint Sub-Carrier, Bit, and Power Allocation of OFDM System in Fading Channels

In this paper, we proposed an efficient joint subcarrier, bit and power allocation algorithm which tries to minimize the total transmit power for OFDM system, while maintaining the BER constraint and the rate requirement of each user. Some existing allocation algorithms allocate resources based on the "best channel gain" rule, which made some resources assigned to the users which are in deep fading. In this paper, we swap the sub-carriers between users to minimize the transmit power after the sub-carrier allocation is decided. Simulation results show that the performance of the proposed algorithm is much better than that of the other algorithms.