| Location information is an import connection between the physical world and cyberspace, and it is a very import factor in the human society. Now people's lifestyle has changed, 80% of the time every day we active in the indoor environment, but the indoor environment GPS technology can not achieve satisfying positioning accuracy.With the increasing coverage of WiFi and the increasing popularity of mobile terminals, indoor positioning research of WiFi-based smart phone received more and more attention.At present, the WiFi indoor positioning algorithm based on the smart phone falls into two categories: indoor positioning based on distance measurement and indoor positioning based on RSSI fingerprint. These two positioning algorithms encountered many challenges in the actual positioning. The indoor positioning algorithm based on distance measurement carries on geometric constraint location according to the principle of wireless distance measurement. The value of signal intensity fluctuates greatly, due to the multipath effect of the indoor environment, which makes the positioning accuracy very low. The premise of Fingerprint positioning algorithm based on RSSI is to build an accurate fingerprint database, while the construction of RSSI fingerprint data needs to spend a great deal of labour cost on-site inspection survey and acquisition.In this thesis, aiming at the challenge of indoor positioning based on distance measurement and indoor positioning based on RSSI fingerprint. This article is structured as two parts follows:(1) In this thesis, aiming at the problem of large positioning error caused by wireless ranging, a new adaptive error correction algorithm based on smart phone is proposed, and the correction factor is used to improve the accuracy of wireless ranging, which reduces the positioning error.(2) In order to solve the problem of manual fingerprint data acquisition based on RSSI fingerprint location. In this thesis, we use wireless sensor network to collect the fingerprint data in the framework of fingerprint data based on RSSI, and proposed an algorithm for sparse sampling indoor fingerprint construction, and use a sparse representation technology to effectively reduce the cost of data transmission in wireless sensor networks.The results of this study have got satisfying effects. In the case of ranging, the signal adaptive correction algorithm of smart phone-based will improve the positioning accuracy by 35.9%. In this thesis, aiming at the problem of prices of fingerprint acquisition based on fingerprint data positioning, fingerprint algorithm for sparse sampling is effective in reducing the acquisition cost under the condition of guaranteeing the precision of fingerprint data. |
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