On the Outage Properties of Adaptive Network Coded Cooperation (ANCC) in Large Wireless Networks

Adaptive-network-coded-cooperation (ANCC) is an efficient user cooperation scheme proposed for large wireless networks comprising a host of terminals communicating with a common destination. By matching code graphs with instantaneous network graphs in a distributed and adaptive manner, the protocol enables network coding to be exploited in networks with unreliable channels and changing topologies. This paper analyzes the outage behavior of ANCC when the number of terminals trends to infinity. A threshold phenomenon is revealed which demonstrates that an arbitrarily small outage can be achieved with a sufficiently large network as long as the channel conditions are above a certain threshold. Comparison with the existing cooperation schemes shows that ANCC achieves a substantial gain of 30 dB over repetition, and falls only 1 dB short of space-time-coded-cooperation (but obviating the need for stringent inter-user synchronization)