This letter presents an experimental study of an indoor environment regarding the performance of a multiple-input-multiple-output orthogonal frequency-division multiplexing (MIMO-OFDM) millimeter-wave system based on the standard IEEE 802.15.3c. Channel matrices are measured with a vector network analyzer, and in a first step, the intrinsic propagation characteristics are analyzed such as the path loss, capacity, and correlation. In a second step, the performance is studied using different space-time coding strategies. Finally, all this analysis is conducted with respect to different configurations of the MIMO antenna elements.