Outage-optimal relay selection in wireless sensor networks using fuzzy comprehensive evaluation

This paper focuses on the problem of selecting the optimal common node (CN) in a wireless sensor network to serve as the relay to aid the data transmission between the cluster head (CH) and the data fusion center (DFC). Optimal relay selection with the objective of minimizing the outage probability is a difficult problem which depends on multiple factors. In this paper, an outage-optimal relay selection algorithm using fuzzy comprehensive evaluation is proposed. The algorithm takes into consideration both the channel state information and the cooperation power information of the nodes, and uses fuzzy comprehensive evaluation to select the optimal relay. The optimum fuzzy weight, which guarantees the optimality of the proposed relay selection algorithm in terms of the outage probability, is specified using general-purpose iterative methods. Simulation results show that the proposed relay selection algorithm evidently outperforms the algorithm based only on the channel state information in terms of the outage probability.