Design and Implementation of Pre-processing System for DMB Early Warning Information

摘要

In order to realize visualization transmission for early warning information, a pre-processing system of DMB (Digital Multimedia Broadcasting) is proposed. The system is mainly composed of information compression, TS (Transport Stream) combination, error correction and intelligent stream rate control. Due to huge amount of multimedia information, warning information is compressed firstly. Then, compressed multimedia information is combined to transport stream to output. In order to improve communication reliability, error correction is realized through RS (Reed Solomon) encoding and external convolution interleaving. Furthermore, because output stream rate is changeable, a method based on inserting null packets is proposed. By this method, output TS stream rate is constant at 384 kbps and it meets the further requirement of early warning releasing. The whole system has been validated by experiments and has outperformed former DAB (Digital Audio Broadcasting) preprocessing system for early warning information in both reliability and stability.