Robust LT codes with alternating feedback

In this paper, we propose robust LT codes with alternating feedback (LT-AF codes), which lightly utilize the feedback channel and surpass the performance of existing LT codes with feedback. In LT-AF codes, we consider a loss prone feedback channel for the first time and propose the encoder to generate degree-one output symbols (encoded symbols) only in acknowledgement to the reception of feedbacks. Therefore, LT-AF codes become robust against feedback losses meaning that their performance does not deteriorate even at high feedback loss rates in contrast to previous work. To realize this, we design a new and parameterless coding degree distribution for LT-AF coding based on Ideal-Soliton (IS) distribution of LT codes.