An efficient multiplexing method of T-DMB and cell broadcast service in emergency alert systems

This paper presents a novel multiplexing method of T-DMB and cell broadcast service for robust emergency alert service in mobile stations. In the method, the cell broadcast service is used as a primary device for detection of an emergency alert message. If a detection outage occurs, the T-DMB is enabled as a secondary device for detection of the alert message, which guarantees more reliable alert message delivery. For better detection performance of emergency alert messages in the T-DMB, a channel estimation scheme is proposed, which is based on a divide-and-conquer algorithm. The presented estimation approach effectively exploits the phase reference symbol of TDMB. The simulation results confirm that the multiplexing and channel estimation approaches produce better alert delivery performance in an emergency alert system.