Joint power control and sub-channel allocation for co-channel OFDMA femtocells

Two-tier networks consisting of macrocell and femtocells are provided as a solution to increase capacity and improve indoor coverage of cellular networks. In two-tier networks, when the spectrum is shared by macrocell and all of femtocells, the cross-tier and co-tier interference should be taken into account. In this paper, we investigate the power control problem of minimizing the aggregate transmit power for macro-tier and the joint power control and sub-channel allocation problem of maximizing the total rate for femto-tier, both in uplink transmission, while the cross-tier and co-tier interference are both taken into account. Then, to solve these problems, we propose distributed sub-optimal algorithms for both macro and femto-tier. Finally, simulation results are presented to confirm out performance of our proposed algorithm and to compare with the existing algorithm.