BER analysis of ST-Block coded MIMO-OFDM systems with frequency domain equalization in quasi-static mobile channels

Multiple-Input Multiple-Output Orthogonal Frequency Division Multiplexing (MIMO-OFDM) has become one of the key technologies for the Beyond 3G and 4G broadband wireless communications. MIMO channels increases the capacity (by a factor of the minimum number of transmit and receive antennas), data rate and immunity to Inter Symbol Interference (ISI) (due to concatenation with OFDM) particularly under frequency selective channels. To increase reliability and for robust transmission, coding can be done in space, time and frequency domains provided by MIMO-OFDM. In this Paper, a general Space-Time Block Coding (STBC) structure is presented in MIMO-OFDM systems. BER performance of STBC along with different equalizers is investigated and then optimum equalization method is suggested. Furthermore, Simulations are carried out with 2 transmit, 1 receive antenna and then with 2 transmit, 2 receive antenna MIMO-OFDM systems under both frequency flat and selective channels.