Energy-Efficient Adaptive Transmission Scheme in a Correlated Wireless Sensor Network

In this paper, we develop an adaptive transmission scheme in a wireless sensor network (WSN). Distributed sensors can cooperate with the neighborhood and transmit their data to the data collector by choosing a proper transmission mode adaptively based on the channel conditions and spatial correlation among the sensors. By investigating the statistical properties of a correlated virtual multiple-input multiple-output (MIMO) channel between the sensors and data collector, we assess the analytic performances of two different MIMO transmission modes -- spatial multiplexing and transmit diversity achieving schemes. We also evaluate energy efficiencies of two MIMO transmission modes. Based on these result, we derive a new energy efficient mode switching criterion between spatial multiplexing and transmit diversity suitable to a WSN.