We propose a multi-band (MB) - orthogonal frequency division multiplexing (OFDM) ultra wideband (UWB) system for the wireless transmission of high-definition (HD) video signals from a set-top box to HD monitors. The system supports both single and multiple antennas by improving WiMedia. The proposed system with multiple antennas having a diversity order of four can support a data rate of at least 1 Gbps with reduced complexity. The proposed WiMedia system with multiple-input multiple-output (MIMO) technology is very robust against to the shadow fading.