Improved intermediate performance of rateless codes

Rateless erasure resilient codes, e.g., LT codes, can recover all message symbols perfectly with high probability from a slightly greater number of encoding symbols. However, it has been observed that only a few message symbols can be recovered from a less number of encoding symbols. In this paper, we investigate the performance of rateless codes when the number of received encoding symbols is less than that of the original message symbols. Through ordered generation of encoding symbols according to their degrees, we demonstrate that a significantly improved intermediate performance of rateless codes can be obtained.