Abstract: For arbitrary-tap frequency selective multiple-input multiple-output(MIMO) Nakagami fading channels,we derive exact and approximate closed-form expressions for the average symbol error rate of space-frequency block coded(SFBC)-orthogonal frequency division multiplexing(OFDM)systems with rectangular M-ary quadrature amplitude modulation(QAM)by using moment generating function (MGF)based analysis approach and the exponential bounds for the Gaussian Qfunction. Numerical and simulation results show that the theoretical analysis is exact and the approximate analysis is accurate.