Belief propagation decoding assisted on-the-fly Gaussian elimination for short LT codes

Belief propagation (BP) decoding has been widely used for decoding Luby transform (LT) codes which perform very well for a large number of input symbols. However, in reality, small numbers of input symbols are often encountered. In this paper, an efficient BP decoding assisted on-the-fly Gaussian elimination (OFG) decoding process is proposed. Our algorithm exploits XOR operations to get a packet of degree one when the ripple is empty, which gives a small value of overhead. Simulation results show that the proposed algorithm gives a largely improved overhead, about a 0.25 or more, with respect to that of the conventional BP algorithm. The complexity of the proposed algorithm is notably reduced with respect to that of OFG, especially in case of -500, while guaranteeing the overhead nearly same as that of OFG.