Efficient GF(256) Raptor Code Decoding for Multimedia Broadcast/Multicast Services and Consumer Terminals

The past few years have seen a tremendous growth in the network connectivity in the consumer electronics market leading to unprecedented increase on the Internet data traffic. The main service contributing to that enormous information flow is mobile multimedia delivery for consumer devices. The fountain codes and their derivative Raptor code in particular, are a preferred coding technology for forward error correction (FEC) at the application layer of Multimedia Broadcast/Multicast Service (MBMS) systems. Currently, a next generation Galois Field GF(256) Raptor code has been specified for these services. The new rateless code aims at further reducing to a minimum the redundant FEC information compared with its well-established predecessor - Raptor code. However, this comes at the expense of increased decoding complexity. The main contribution of this manuscript is a new, optimized version of the inactivation decoding Gaussian elimination algorithm (IDGE) over GF(256) finite field, which offers significant decoding performance improvement. To prove and demonstrate the efficiency of the newly proposed algorithm, the manuscript analyzes and compares the complexity and the performance of the GF(256) Raptor code with respect to Raptor code. The simulation experiments are performed on both personal computer and embedded system platform ends of the consumer electronics market. Various memory mapping schemes are considered. Additionally, the manuscript demonstrates the behavior of the GF(256) Raptor code in a real time MBMS system scenario.