Novel LT coding scheme with limited feedback in broadcast systems

Digital Fountain, which is widely used as practical forward error correction (FEC) solution, has been applied in many single-way broadcast communication systems. In this paper, we propose a novel feedback scheme for Luby Transform (LT) codes. The proposed modified LT coding scheme significantly reduces the number of encoded symbols, which are needed at the decoder to recover all input symbols. It is proved that the suggested scheme is very well suited to broadcast systems. Then we propose two algorithms which are named All Random (AR) and Levelly Search (LS) algorithms which can be properly used in broadcast models. Simulation results show that the proposed scheme outperforms the traditional LT in both unicast and broadcast systems with limited feedback. And both the AR and LS algorithms are effective in reducing the total amount of encoded symbols.