The Digital Fountain Codes Decode Method Based On The Classify Of The Encode Symbols With Degree 2

In recent years, as the rapid development of mobile communication technology and Internet, multimedia broadcast and multicast technology has been widely used. And as China's comprehensive national strength, the strength of the development of space, deep space exploration have also been more widely attention. Fountain code technology which by virtue of superior performance be introduced into various communications applications and development. In this paper, as the research object fountain code, decoding of fountain-depth research programs, to improve the performance of fountain codes, to expand its range of applications, improve efficiency and quality of communication to make a contribution.Fountain codes is a new rateless coding scheme, the encoding information packet does not simply copy the original information packet, but adding a few original results of the packet of information. Encoder can produce any number of code words, through the transmission channel to the receiver without the need to know specific information channel; receiver receives a certain amount as long as the codec pack, codec pack as long as the received slightly larger than the number of original information number of packets, you can restore to a very high probability that the original information, thus completing the communication.Each package contains a coding number of the original information package referred to as the degree of encoding, decoding program for decoding the traditional BP required a large number of packets received, and must be received by 1 degree can begin after the decoding codec pack defects, a packet classification based on degree 2 encoding, codec pack for 3 horses in degrees of the decoding algorithm. The algorithm uses a hypothetical packet of degree 2 encoded packet classification with BP decoding, the resulting degree of the class can quickly be reduced to 3 codec pack codec pack of 1 degree, so that decoding is not limited to In response to the encoding package is 1 degree, and be able to receive the degree by 2 degrees between 3 codec pack, to reduce the degree to form a new degree after 1 encoding decoding packets, so that work can be successfully decoded be.Meanwhile the paper also proposed a packet classification in degree 2 encoded on the basis of the encoding package on a high degree of processing down algorithm using more coding information in an appropriate increase in the amount of decoding computation based on the further improve the decoding success rate.The algorithm used to improve deep-space communications, simulation results show that the new algorithm can be completed to receive information by decoding the limited work, and although the iterative decoding of the calculation slightly increased, but simplify the decoding of subsequent supplementary complexity, increase overall efficiency and quality of communication.