Cooperative Broadcast With Randomized Parity Forwarding

The authors present a randomized parity forwarding technique in cooperative broadcast networks. A single source sends a common message (codeword) to all nodes, and those nodes that correctly decode the message then generate a parity bit and broadcast it to the remaining nodes. The remaining nodes combine the original codeword from the source with the network-generated parity bits to construct a lower rate, and thus more powerful, error correcting code. The protocol overhead is significantly reduced by allowing each relay node to randomly generate a parity bit independent of other nodes. They present the average probability of decoding error and the energy saving as a function of the number of nodes in the network.