Design and Analysis of Online Fountain Codes for Intermediate Performance

TL;DR

This paper introduces new online fountain coding schemes that improve intermediate decoding performance while reducing full recovery overhead, balancing efficiency and reliability.

Contribution

It proposes OFCNB and SOFC methods that enhance intermediate performance and lower recovery overhead through theoretical analysis and simulation validation.

Findings

OFCNB improves intermediate performance by removing build-up phase.

SOFC achieves better intermediate performance and lower recovery overhead at low erasure rates.

Simulations confirm the superiority of proposed codes over existing online fountain codes.

Abstract

For the benefit of improved intermediate performance, recently online fountain codes attract much research attention. However, there is a trade-off between the intermediate performance and the full recovery overhead for online fountain codes, which prevents them to be improved simultaneously. We analyze this trade-off, and propose to improve both of these two performance. We first propose a method called Online Fountain Codes without Build-up phase (OFCNB) where the degree-1 coded symbols are transmitted at first and the build-up phase is removed to improve the intermediate performance. Then we analyze the performance of OFCNB theoretically. Motivated by the analysis results, we propose Systematic Online Fountain Codes (SOFC) to further reduce the full recovery overhead. Theoretical analysis shows that SOFC has better intermediate performance, and it also requires lower full recovery overhead when the channel erasure rate is lower than a constant. Simulation results verify the analyses and demonstrate the superior performance of OFCNB and SOFC in comparison to other online fountain codes.