Atmospheric turbulence produces fluctuations in the irradiance of the transmitted optical beam, severely degrading the performance over optical wireless links. Performance of optical wireless communication based on low-density parity-check (LDPC) codes and multiple-input multiple-output (MIMO) is investigated. Decoding algorithm of repetition coded MIMO (rep MIMO) and space-time coded MIMO (ST MIMO) based on LDPC codes is investigated, finally it is simulated in the atmospheric turbulence channel. Simulation results show that rep MIMO outperforms ST MIMO, and LDPC codes have excellent error correction capabilities and access to a larger coding gain. Therefore the sheme based on LDPC codes and rep MIMO can mitigate fading effectively.