Energy-Efficient Cooperative Communication in Clustered Wireless Sensor Networks

We study a clustered wireless sensor network where sensors within each cluster forward the message to another cluster via cooperative communication techniques. Only those sensors that correctly decode the packet from the source can participate in the subsequent cooperative communication. Hence, the number of cooperating sensors is a random variable depending on both channel and noise realizations. We formulate a multi-variable optimization problem to minimize the overall energy consumption. With numerical methods, we investigate how the energy efficiency is affected by the transmit power allocation, the total number of sensors in a cluster, the end-to-end packet error rate requirement, and the relative magnitudes of intra-cluster and inter-cluster distances.