This paper presents a MIMO-OFDM baseband transceiver design for indoor gigabit wireless communication systems. The proposed system uses 5 GHz carrier frequency with bandwidth up to 160 MHz. Both the transmitter and the receiver support 4 antennas. At the receiver, we design symbol timing detector, carrier frequency offset first acquisition and subsequent tracking mechanisms, channel estimation and MIMO detection. Simulation results show that the proposed symbol timing detection algorithm is more precise than the conventional algorithm. The CFO tracking mechanism also helps to improve the severe degradation in MIMO detection due to the residual synchronization error. In addition, by exploiting low-correlated spatial diversity, this system can combat highly frequency-selective fading channels for wide-band applications. We thus achieve satisfying system performance with 64-QAM constellation for 2.6-Gbps transmission rate.