Research And Application On Digital Fountain Code In Streaming Media Transmission System

With the development of the Internet,the amount of network data continues to increase,people care the video quality and real-time requirements getting higher and higher.How to improve the performance of network data transmission,enhance the data packet loss rate and anti-error rate,which is the research direction of many scholars in recent years.Commonly used ARQ automatic retransmission mechanism,can effectively improve the reliability of data transmission,but it is at the expense of throughput and network delay.So a flexible and scalable digital fountain code technology has been a wide range of industry researchers of all ages.In this paper,cascade the improved LT code and pre-coding as an improved Raptor code which is based on the traditional LT code.the specific work is as follows:1.Firstly,the research background and research status of this paper are expounded,and several key technologies of streaming media transmission are briefly introduced.And then introduced the erasure channel and system code,and thus leads to the rateless of digital fountain code and its principles.2.Based on the traditional LT digital fountain code,the improved LDCM-LT cascaded Raptor code is proposed.The LDGM Triangle is used as the precoding of the Raptor code,and the degree distribution of the LT code is improved on the basis of the robust solitary wave distribution,and the improved Raptor code is simulated.3.For the harsh network environment,proposed a kind of unequal error protection Raptor code,with higher priority data for a higher level of protection.The simulation results show that digital fountain codes with different error protection digital fountain codes have better performance than error protection digital fountain codes.4.Finally,the improved Raptor code is applied in the streaming media transmission system,and the detailed design scheme is given.Finally,the transmission packet loss test is carried out.The results show that the Raptor transmission system based on this design has strong of the anti-packet loss performance,in line with the expected design goals.