Cooperative communication strategy for energy hole mitigation in wireless sensor networks

This paper proposes a cooperative communication-based approach to mitigate the energy hole problem in wireless sensor networks. The approach contains a cooperative transmission strategy and a power allocation scheme. In the cooperative transmission strategy, nodes transmit relay data through cooperative multi-input single-output (MISO) transmission with the next-hop relay node to balance the energy consumption between nodes and their relay nodes. Based on this strategy, a power allocation scheme is studied to further balance the energy consumption among nodes. The power allocation problem is established, where the average bit error rate (BER) constraint and the balanced energy consumption condition should be satisfied simultaneously. The solution can be obtained by an iterative searching algorithm. Performance analysis results show that the cooperative transmission strategy with the power allocation algorithm can effectively mitigate the energy hole problem and significantly improve network lifetime. In large networks, the network lifetime can be improved up to 9 times compared with that achieved by the conventional single-input single-output (SISO) transmission strategy. Moreover, the larger the network, the better it performs in lifetime extension.