Channel Adaptive Prioritized Network Coding

We propose a channel adaptive prioritized network coding technique that provides a variable quality of service (QoS) to different nodes in multiple access relay networks (MARN). The basic idea is to exclude the low priority nodes in the network encoder when their channel gains towards the destination are above a threshold, and vary the threshold to provide a variable QoS. The proposed technique can provide a soft-level prioritized service to different nodes depending on their assistance needs. They are a natural generalization of current prioritized network coding techniques which can provide only a hard-level (fixed) prioritized service. We derive the outage probability for the prioritized and non-prioritized nodes in Rayleigh flat fading channel with additive white Gaussian noise and derive optimum threshold based on QoS constraints.