In this paper, we are interested in blind and semi-blind identification of multiple-input multiple-output (MIMO) channel for orthogonal frequency division multiplexing (OFDM) systems. Using the sparsity property of wireless channel impulse response, we propose an iterative method which minimizes a cost function to result from the combination of blind or semi-blind criterion and the lp norm. This norm is considered as a good sparsity measure. The simulations show that the proposed method outperforms existing techniques in terms of estimation error and robustness to channel order overestimation.