Research And Application Of Distributed Unequal Error Protection Fountain Codes

Fountain codes are widely used in various fields because of their good error correction performance.The distributed Fountain code is the application of Fountain codes in the multi-source relay communication system.In the multi-source relay communication system,the original data length of each source and the demand for transmission reliability may be different.In this case the distributed Fountain codes can be adopted to provide Unequal Error Protection(UEP)for different sources,thus Distributed UEP(DU)-Fountain codes are proposed.This paper focuses on DU-Fountain codes.Our contributions are as follows:First,an improved processing algorithm is proposed to solve the problem that some output symbols have too large degree due to the processing algorithm of the relay in the two-source DU-Fountain codes.The algorithm proposed in this paper optimizes the degree distribution by decreasing the probability of occurrence of the output symbols whose degrees are too large.The simulation results show that this algorithm can improve the decoding performance of the DU-Fountain codes while preserving the unequal error protection property of the original algorithm.Secondly,this paper presents a scheme based on DU-Fountain codes for wireless body area network(WBAN).The scheme combines the channel characteristics of WBAN and provides a method for adjusting the parameters according to the channel conditions.The simulation results show that when the packet loss rate of a certain channel changes,the adjustment of the parameters can improve the recovery rate of packets from two sources to a certain level.The new scheme can adapt itself to the variability of the channel while providing unequal error protection for different sources and eliminate the adverse effects on the recovery of the source packets due to frequent changes in channel conditions.