Quality-Aware Instantly Decodable Network Coding

In erasure broadcast channels, network coding has been demonstrated to be an efficient way to satisfy each user\´s demand. However, the erasure broadcast channel model does not fully characterize the information available in a "lost" packet, and therefore any retransmission schemes designed based on the erasure broadcast channel model cannot make use of that information. In this paper, we characterize the quality of erroneous packets by Signal-to-Noise Ratio (SNR) and then design a network coding retransmission scheme with the knowledge of the SNRs of the erroneous packets, so that a user can immediately decode two source packets upon reception of a useful retransmission packet. We demonstrate that our proposed scheme, namely Quality-Aware Instantly Decodable Network Coding (QAIDNC), can increase the transmission efficiency significantly compared to the existing Instantly Decodable Network Coding (IDNC) and Random Linear Network Coding (RLNC).