A Low Complexity Localization Algorithm in Wireless Sensor Network

Localization is one of the most challenging and important issues in wireless sensor networks (WSNs), especially if cost-effective approaches are demanded. Range estimation is essential in many sensor network localization algorithms. Although wireless sensor systems usually have available received signal strength indication (RSSI) reading, but RSSI is susceptible to external influences, performances unstably, this information has not been effectively used in the existing localization algorithms. RSSI and LQI is good indicator which can reflect the changes in signal intensity and interference of channel with distance changing. LQI varies over a wider range over time for a given link which has a higher resolution. In the localization algorithm, LQI values are introduced to make more precise estimates in node localization. This paper proposes a weighted centroid localization algorithm based on RSSI and LQI. Combined with the rules of selecting fine anchor nodes, it uses weight coeffient to evaluate position accuracy of nodes. This algorithm is simple and no communication is needed while locating. Experimental results shows that the localization algorithm improve the accuracy and stability and meets the application´s need.