Analysis And Design Of Digital Fountain Code Based On AWGN Channel

The information on the Internet is transmitted in the form of data packets.Obviously, the reliability of the information is especially important. The digital fountaincode is one of the most effective technologies which can transfer data reliably in thefuture wireless communication. It aims at massive data delivery and the reliability ofbroadcasting and applies to every kind of data broadcast systems. It could solve theseproblems effectively in the network layer such as the low probability of data delivery,large time delay and bad utilization of the heterogeneous network.This thesis mainly contains three sections.Firstly, the encoding and decodingalgorithms of the fountain code is analyzed based on AWGN channel in detail. TheirBER performance is also provided by the simulation and made a comparison withdifferent information length. Then it compares Raptor code’s BER performance with LTcode’s.Secondly, the convergence performance of the fountain code is described andanalyzed by the extrinsic information transfer charts of the variable node and checknode in different SNR in this thesis. Thirdly, some application areas focus on some partsof the information, so the fountain code’s UEP is used for protecting the relativelyimportant information. There are two traditional methods and an improved methodnamed pUEP-LT given and analyzed here. These methods are realized by changing thesize of the input symbol sets for the protection of the relatively important information.By simulation and analysis, the BER of the MIB and LIB of the pUEP-LT is better thanthat of the given methods. Moreover, the influence for pUEP-LT is analyzed andsimulated in different iterations.The contents of this thesis provide a theoretical basis for UEP-LT’s application inMBMS and AV of the wireless communication.