A New Spread-spectrum System with Four Phases Space-time Modulation for Direction-finding and ranging

To meet the challenge of future mobile communication and integrated communication and radiolocation systems, a new spread-spectrum system with space-time modulation technology is proposed, with which the system can transmit azimuth and communication message. The transmitting scheme with 36 elements circular array antennae and the spread-spectrum receiver are designed. The performance of the bit error rate and direction-finding are analyzed. Simulation results show that the performance of the bit error rate and spectrum have no influence when the modulated signal carries azimuth message. This technology is the development of modulation theory and a new form of smart antenna.