Raptor Codes in the Low SNR Regime

Piggybacking Codes for Network Coding: The High/Low SNR Regime

We propose a piggybacking scheme for network coding where strong source inputs piggyback the weaker ones, a scheme necessary and sufficient to achieve the cut-set upper bound at high/low-snr regime, a new asymptotically optimal operational regime for the multihop Amplify and Forward (AF) networks.

On Channel Coherence in the Low SNR Regime

The current study of the low SNR fading channels focuses on two extreme cases: the coherent case with perfect channel state information (CSI) available at the receiver, and the non-coherent case with no hope to obtain the channel information at all. Most of practical channels, with a low SNR and a slowly varying channel, lies in between these two extremes. In this paper, we use training based s...

Summary of Raptor Codes

A fountain code produces for given set of k input symbols (x1, . . . , xk) a potentially limitless stream of output symbols z1, z2, . . .. The input and output symbols can be binary vectors of arbitrary length. Each output symbol is the sum of a randomly and independently chosen subset of the input symbols. Information describing the relations between input and output symbols is obtained at the...

Raptor codes pdf

Raptor Codes and Cryptographic Issues

In this paper two cryptographic methods are introduced. In the first method the precence of a certain size subgroup of persons can be checked for an action to take place. For this we use fragments of Raptor codes delivered to the group members. In the other method a selection of a subset of objects can be made secret. Also, it can be proven afterwards, what the original selection was.