Node Addition Method of Removing Rings for Fountain Code

Traditional communication coding method is difficult to solve the deep space communication exists in the distance, time delay and asymmetry of up-link and down-link and other issues, so choose the fountain code as a deep space communication system channel coding. The paper analyzes the generation principle of LT codes and the factors that affect the performance of LT codes, in which the small loops in the generated matrix are the main factors. A method of adding nodes in Tanner graphs is proposed to remove small loops. The simulation results show that the performance of the LT code is improved and the system reliability is improved.