An efficient sub-carrier and rate allocation scheme for M-QAM modulated uplink OFDMA transmission

In this paper, we propose an algorithm that allocates sub-carriers to users in the uplink of a multi-cell OFDMA system. This algorithm maximizes the total system capacity on each cell by providing the least number of sub-carriers with minimum power to each user subject to its data rate, available power and error rate requirements. Under this proposed scheme, each user is assigned with a subset of sub-carriers selected from the list of available sub-carriers that are sorted in descending order of signal to interference plus noise ratio. Our numerical study suggests that the proposed algorithm is capable of outperforming other existing schemes (including the fixed carrier allocation scheme in IEEE 802.16) in terms of spectral efficiency, bit error rate, and overall capacity.