Virginia Tech Space-Time Advanced Radio (VT-STAR)

With the integration of the Internet and multimedia applications in next generation wireless communications, the demand for reliable high data rate services is rapidly growing. Traditional wireless communications systems use a single input single output (SISO) channel, meaning one antenna at each side of the link. Information theory research has shown an enormous potential growth in the capacity of wireless systems by using multiple element array (MEA) technology at both ends of the link. Space-time coding exploits the spatialtemporal diversity provided by the multiple input multiple output (MIMO) channel, significantly increasing both the system capacity and the reliability of the wireless link. The Virginia Tech Space-Time Advanced Radio (VT-STAR) system presents a visual demonstration of the capabilities of space-time coding techniques. The VT-STAR system has integrated an MPEG-2 video stream to show a representation of the effect of the wireless channel on a video transmission in real-time. Core algorithms are implemented on Texas Instruments TMS320C67 Evaluation Modules (EVM). Data conversion between the digital and analog domains is performed by TI THS5661 EVM and TI THS1206 EVM for the transmitter and receiver, respectively. The radio frequency subsystem is composed of multi-channel transmitter and receiver chains implemented in hardware. The capabilities of the MIMO channel are demonstrated in a non-line of sight (NLOS) indoor environment. Real-time monitoring of physical layer parameters, such as the bit error rate and diversity advantage, as well as a video display are presented on an attached personal computer.