LDPC FEC code extension for unequal error protection in DVB-T2 system: Design and evaluation

The Digital Video Broadcasting organisation has recently introduced the second generation of terrestrial broadcast transmission standards, DVB-T2. The newly introduced tools ensure significant gain in performance of DVB-T2 compared to the first generation variant of the standard. One of these tools is the new physical layer concatenated forward error correction code. The inner among the concatenated codes is the Low-Density Parity Check code. The paper proposes a method to extend this code so varying coding strength inside one physical layer pipe of DVB-T2 is enabled in a backward compatible way. As consequence, unequal error protection transmission scheme at a physical layer of DVB-T2 can be efficiently deployed. The paper provides a step-by-step description of the design procedure of the extension. Moreover, the modification to the processing chain and the framing structure of DVB-T2, that ensures backward compatibility to the legacy system, is provided. The proposed method is evaluated under AWGN channel and TU6 channel. Experiments performed on four different video sequences show significant improvements in quality of experience when the proposed extension is used to achieve UEP transmission. Copyright © 2012 Lukasz Kondrad et al