Encoding and Decoding of LT Codes Based on Chaos

Abstract

Fountain codes provide an efficient way to transfer information over erasure channels like Internet. LT codes are the first codes fully realizing the digital fountain concept. They are asymptotically optimal rateless erasure codes with highly efficient encoding and decoding algorithms. In theory, for each encoding symbol of LT codes, the neighours used to generate that encoding symbol are chosen uniformly at random. Practical implementations of LT codes usually realize the randomness through pseudo-randomness number generators like linear congruential method. In this paper, we apply the pseudo-randomness of chaotic sequence in the implementation of LT codes. Two Kent chaotic maps are used to determine the degree and neighbour(s) of each encoding symbol. We show that the implemented LT codes based on chaos perform better than the LT codes implemented with the traditional pseudo-randomness number generator.