Abstract
In the recent years, wireless broadcast communication systems have become an important role for multimedia transmission. Broadcasting are more appropriate transport technologies to cope with high numbers of users consuming simultaneously the same service when compared to unicasting, as there is no limit to how many users can receive the content. For example, mobile TV services for portable devices, as video clips from movies to TV dramas are suitable for wireless broadcast communication networks. Fountain codes can generate a potentially limitless stream of encoded symbols. Regardless of the channel condition and the order of received output symbols, once receivers get enough encoded symbols, they can recover all the source symbols. Therefore, fountain codes are efficient for broadcast systems with the erasure channel particularly. LT codes are a class of fountain codes with the simple encoding and decoding algorithm which provide reliable broadcast communications over erasure channels with unknown erasure probability. The ARQ scheduling is often employed to improve more throughput efficiency and reliability for retransmission. In this thesis, we evaluate the performance of LT codes and those with ARQ schemes. We propose a scheme which uses LT codes and an efficient hybrid ARQ scheduling algorithm with incremental redundancy symbols for broadcast communications over erasure channels. Since the number of incremental redundancy symbols for retransmission determines the throughput efficiency, we make a proper scheduling arrangement on incremental redundancy symbols. Simulation results show that comparing to other known schemes, our proposed scheme is with the least number of incremental redundancy symbols than that of others and therefore achieves better performance.