Dynamic Forward Error Control Schemes

The dynamic error control scheme is highlighted in this chapter. It is shown that a flexible dynamic error control coding becomes more and more desirable in wireless mobile communications to accommodate different error protection requirements, or time-varying channels. The FEC and ARQ/FEC schemes are two important underlying techniques for the realization of the dynamic error control scheme, wherein the CSI and CSI-like information are the prerequisite conditions. It is shown that puncturing and extending are two basic techniques to realize dynamic code rate. Generally, the puncturing techniques outperform in the higher-code-rate region, while the extending outperforms in the lower-code-rate region. Combining both techniques leads to the best of both worlds. The forward error control coding schemes of both DVB-T and DVB-H are presented to indicate the most important problems when realizing the dynamic error control scheme in mobile broadcasting scenarios. Finally, it is stated that although further investigations are needed, the technique of the dynamic error control scheme has great potential in the practical applications of mobile multimedia broadcasting.