Research On Digital Fountain Codes Encoding Decoding Algorithm And Simulation

With the development of network technology, the society is high on the wireless communication transmitting and receiving quality and efficiency requirements are getting, wireless communication technology has been widely applied in various fields, and the channel quality of wireless channel is bad, will affect the reliability of communication, fountain codes as a forward error correction technology, can effective against channel interference, it is suitable for applications in wireless networks, based on fountain codes as the research object, in the encoding and decoding algorithm and unequal error protection and other aspects to make a certain contribution.Fountain code is a need for a channel feedback to ensure the reliability of data encoding, it is a kind of rateless codes, channel resources can be configured flexibly, so as to achieve efficient and reliable transmission of data. And fountain codes with low complexity, both in military and civil fields, using LT and Raptor codes as the representative of the fountain code plays a very important role, has been more and more attention from industry and academia, based on fountain codes as the research object, the research on degree distribution, fountain codes algorithm, unequal error control. The main work is as follows:First introduces the basic overview of fountain codes, including its characteristics, development history, research status, a representative of the fountain code in detail on several, analyzes their advantages and disadvantages, and the LT code and Raptor code as the object introduces how the encoding and decoding of fountain codes.Secondly, the research on five kinds of fountain codes degree distribution function, average degree distribution, degree-1 distribution, two distribution, the ideal soliton distribution and robust soliton distribution, one of the key factors determining the performance of fountain codes is the fountain codes degree distribution design, and then starting from the design the degree distribution, according to the two representative fountain code LT codes and Raptor codes as the research object, studies the method of encoding and decoding them, and their advantages and disadvantages are introduced, the simulation of fountain codes in different degree distribution was carried out under the condition of the decoding success rate, bit error rate;Finally, the specific application for unequal error protection encoding schemes, are studied in this thesis. The realization method of UEP fountain codes, on this basis, proposes an optimization method of UEP fountain codes, the method of analysis of the existing UEP fountain code design method shortcomings, based on further improvement of the existing UEP fountain codes. Certain channel conditions based on the encoding and decoding performance of global optimization of important information and important information. The simulation results show that compared with the traditional UEP fountain code method, optimization design of the whole UEP fountain code has better decoding performance.