Study On Rssi-based Indoor Wireless Location Program

Wireless positioning means making use of the network resources from existing wireless communications network, by estimating the relative signal parameters between mobile terminals and the base station, taking advantage of certain location algorithm to determine the location of mobile terminal. Since the U.S. FCC (Federal Communications Commission)Released the E-911 location standards in 1996,Its infinite potential value on the commercial implication brought a booming studding in this field.Meanwhile,with the rapid development of mobile technology, it creates increasing demands for indoor positioning information, for instance, The airport, exhibition hall,offices,warehouses and underground parking are in urgent demand of these precise indoor location information. As is well-known,GPS can offer very accurate positioning information for these users,However,in high-dense urban buildings and indoor spaces, due to too much blocking filling in these spaces,GPS will not work efficient as it can't receive enough satellite signals, So Indoor wireless location technology studies now become a new craze.In this thesis, through extensive reading of classical thesis from foreign and domestic studiers, as well as the latest research achievement on positioning technology, it offers two indoor wireless localization programmes based on the received signal strength indicator (Received Signal Strength Indicator, RSSI).One programme is based on the dynamic correction RSSI, it refers to the classic Distance - Loss consumption model, proposes a new point-distribution plan, then uses the reference point,the knowledge of weighted average theory and centroid principle to make out the coordinates of moving points. This programme,to a certain extent, successfully solves the positioning error problem caused by the Distance - Loss model distortion due to the complex and changing environment. Another programme is based on changing trend of the indoor RSSI ,this programme set aside all the complex positioning model, regard of the particular geographical environment, utilize the interrelationship between RSSI changing Trends and the distance to acquire positioning information. This way means a low cost with proper positioning accuracy, and it doesn't need too many equipments to support the positioning activities. So this positioning programme is a good solution when positioning activities comes across too complex indoor environment, or such activities demand a low cost and not too accurate positioning information.