Abstract
This paper presents a cooperative single-input multiple-output (SIMO) transmission scheme for wireless sensor networks (WSNs), where the number of antennas and the constellation size of modulation are jointly optimized for different transmission distances such that the energy consumption is minimized. As compared to previous cooperative MIMO schemes for WSNs, the proposed one achieves higher energy efficiency and has a smaller critical distance above which cooperative MIMO/SIMO outperforms single-input single-output (SISO). The proposed optimization method is further extended to a clustered multi-hop WSN scenario. Through joint optimization of the number of transmitter antennas, the number of receiver antennas, the constellation size, and the hop length, we derive an energy-efficient clustered cooperative SIMO multi-hop scheme. Numerical results show that the proposed scheme not only reduces the overall energy consumption but also balances the energy consumption among clusters. ©2009 IEEE.