Design and analysis of collaborative diversity protocols for wireless sensor networks

We consider wireless sensor networks where all the sensor nodes share the same channel and transmit collaboratively in a quasi-static Rayleigh fading environment. Intuition suggests that collaborative communication can achieve a higher diversity gain than traditional SISO systems. Based on a decode-and-forward approach, we propose spectrally efficient variable-rate two-phase protocols that can achieve full diversity and analyze the effect of node geometry on their performance in terms of the outage probability of mutual information. Numerical results show that, provided the collaborator node is close to the source node, full diversity gain can he readily achieved without loss of bandwidth efficiency.