Abstract: To get full diversity available in the MIMO-OFDM systems with frequency selective quasi-static block fading, the algebraic space-time coding and Hadamard transform are utilized to get a new space-time-frequency block coding (STFBC) to get full diversity. The full diversity is a product of the number of the transmit antenna Mt, receiver antenna Mr and channel taps L in a quasi-static block fading channel. When there are 4 transmitting antennas, the proposed STFBC can reach symbol transmission rate of two. Compared with other STFCs, it makes a good tradeoff between rate-one STFC and rate-four STFC in 4-transmitter MIMO-OFDM systems. Simulation results show validity of our technique.

Key words: space time frequency block coding(STFBC ), diversity, orthogonal frequency division multiplexing, frequency-selective fading