Energy Efficient Precise Localization in WSNs

Due to energy limitation in WSN, any algorithm used in these systems should be energy efficient. Increasing accuracy of localization in Wireless Sensor Networks (WSNs) has been widely studied, without paying attention to energy consumption. In this paper, the accuracy of localization is increased by accurately measuring the distance between the sensors connected to the patients as nodes of a WSN. Limit error in Multiple Input Multiple Output (MIMO) has been calculated by CRB method. Simulation results approve the proposed relation. By using a so called Virtual MIMO (VMIMO) technique, it is shown that both distance estimation error and energy consumption are decreased. Optimum selection of the number of the transmitter and receiver nodes is achieved by the lowest possible energy consumption. Mathematical relation between energy consumption and localization error is presented and then verified by simulation. Using VMIMO decreases power of transmitters and this in turn will result in decreasing destructive effects of electromagnetic waves on patients.