Combinational spreading and modulation technique for mobile satellite DMB services

Satellite digital multimedia broadcasting (S-DMB) service has been launched in Korea in May 2005. S-DMB can provide high quality broadcasting services (audio, video, and data) to handheld mobile receivers via the geostationary satellite. Due to multipath fading, incurred inter-code-interference limits the current S-DMB system to utilize only half the available Walsh code sequences, thereby decreasing channel utility. To maximize the use of broadcast channel resources, we propose a transmission method of combining spreading and code modulation. The efficient use of Walsh code sequences increases the capacity of the S-DMB system in an interference prone environment, without degrading quality of service.