Clustering for cooperative diversity using trellis pruning

A recent paper by the authors demonstrated how two users (or partners) could cooperate to convey their data to a common destination through trellis pruning. With this technique, both “local” and relayed data are multiplexed together prior to modulation; then, the partner's decoder exploits its knowledge of the relayed data by pruning the code trellis to effect a lower rate (more robust) partner-to-partner link. This paper extends this technique to larger clusters of users cooperating to convey their data to a common destination. The protocol is first demonstrated for n=3 users, and a significant performance gain is demonstrated over time-sharing in a Rayleigh fading environment. Then, the general protocol is derived and conclusions regarding performance are presented.