An indoor positioning system based on tof for wireless sensor networks

Wireless indoor localization has become very popular in recent years. In this paper a novel indoor positioning system based on time of flight (tof) for wireless sensor networks is proposed, designed and implemented. The system operates on two channel sets, one is used for establishing the backbone communication network, and the other one is used for sampling nodes´ position information, which is a set of several channels. The employment of sampling channels makes it easy for the system to assign different channel to the different distinct, which reduce the sample collision. A localization method called unbiased estimate position(URPM) based on multi basestations is also proposed. This method works well, limiting the location accuracy within 3m, which can be further reduced by improving the sampling rates.