Some UEP Concepts in Coding and Physical Transport

Unequal error protection is the key to future transport of multimedia data. The paper presents an overview of some new approaches realizing UEP properties in physical transport, especially multicarrier modulation, or with LDPC and turbo codes. For multicarrier modulation, a UEP bit-loading method is described allowing for an arbitrary number of classes, arbitrary SNR margins between the classes and arbitrary number of bits per class. In turbo coding, pruning, as a counterpart of puncturing is presented for more flexible bit-rate adaptations. Pruning is also the tool that leads to a construction approach for check-irregular LDPC codes with UEP properties.