Decoding with Early Termination for Rateless (Luby Transform) Codes

Fountain codes have recently gained wide attention in communications due to their capacity-approaching performance and rateless properties that allow them to seamlessly adapt to unknown channel statistics. In this paper, we consider the problem of low complexity decoding of Luby transform codes, which are a class of linear fountain codes. We adapt the recently proposed technique of informed dynamic scheduling to the rateless regime, and combine it with the method of incremental decoding to obtain a decoder that has a significantly reduced computational load compared to the commonly used alternative of message-reset decoding with a flooding schedule. This reduction in complexity, in some cases as large as a factor of sixty, is obtained without affecting the error rate performance of the code.