Two Design Schemes for LT Codes Degree Distribution by Combining Degree Distribution

With the rapid development of communication technology and the Internet, digital fountain codes have become a hot topic in many fields. Degree distribution is a key factor affecting the performance of fountain codes. Traditional single degree distribution, such as Ideal Soliton Distribution, Robust Soliton Distribution, and Binary Exponential Distribution cannot satisfy the request of increasing multimedia applications due to their obvious performance defects. So designing a superior performance degree distribution is a challenging task. In this paper, we ought to investigate this challenging issue by presenting two new schemes of degree distribution based on Poisson distribution, Ideal Soliton Distribution and Moved-Robust Soliton Distribution with single-scale coefficient and double-scale coefficient. The simulation results show that the two schemes we proposed have greatly improved in terms of bit error rate, decoding overhead and the ratio of decoding success compared with the known single degree distribution and initial single-scale coefficient combined degree distribution.