An Alternative Indoor Localization Technique Based on Fingerprint in Wireless Sensor Networks

Although several methods based on the RSSI measurement exist for localizing a mobile node in the WSN, a method which can produce precise results is still unavailable. In this study we present an alternative technique based on fingerprint which uses a minimum number of anchor nodes for the detection of the location of a mobile node. In this technique an indoor area is thought as a matrix consisting of rows and columns, and the location of the mobile node is expressed as a cell in this matrix. In the first phase the expanded RSSI map of the indoor area is constructed off-line. In the preceding phase on-line RSSI values and the expanded RSSI map are intersected to find possible cells. Then these cells are compared to the logical sub regions and the location of the mobile node is found. The proposed technique is tested in both simulation and in an experimental setup. The results are compared to the results of nearest neighbour method.