In this paper, the problem of joint sub-channel assignment, antenna selection, and power control in the downlink (DL) of an orthogonal frequency division multiple access (OFDMA) femtocell network is investigated in order to maximize system throughput. This problem, due to its discrete nature and the interference, is modeled as a mixed integer non-linear programming (MINLP) optimization problem, which is complicated to solve. To deal with this complexity, the problem is decomposed into three subproblems: 1) sub-channel assignment, 2) antenna selection, and 3) power control. We then present an iterative algorithm for these subproblems resulting in an optimized network throughput. The superiority of our proposed method compared to other existing works is demonstrated through simulation results.