The Study Of Indoor Wireless Location Algorithm Based On Ultra-Wideband Technology

In recent years, the rapid development of wireless communication technology prompts the wireless location technology to be mature. With the extensive use of traditional outdoor wirefess location technology, people’s demand for wireless precise positioning becomes increasingly strong in the complex indoor environment such as large venues, underground mines, and fire scenes and so on. As UWB signal has the advantages of more strong penetrating power and anti-interference ability, lower cost and power consumption, higher multipath resolution over other indoor localization technologies, the research on ultra-wideband wireless indoor localization algorithm becomes very meaningful.The main work in this paper is as follows:1. From the perspective of UWB wireless communication theory, the characteristics of UWB signals and their channels are analyzed. The principles of UWB indoor positioning system architecture, the transmitter and receiver are researched. At the same time, the reason why the ultra-wideband technology is chosen as the research algorithm of indoor positioning is given.2. IEEE802.15.4a channel model which is proposed by IEEE802.15 working group is analyzed. As the indoor environment becomes more complex, and according to the theory that the different environment need different parameters of channel model, six relevant IEEE802.15.4a channel models for different environment are put forward by IEEE802.15 working group. Because the focus of this paper is to study wirefess indoor precise positioning, the channel model parameters in the residential and office environments are researched.3. The ultra-wideband wireless indoor positioning algorithms including four typical UWB wireless indoor localization algorithms are focused, which are respectively based on Time of Arrival (TOA), Time Difference of Arrival (TDOA), Received Signal Strength Index (RSSI), Angle of Arrival (AOA). And a comparative analysis on the advantages and disadvantages of the four kinds of typical UWB wireless indoor positioning algorithm are made. Combined with the direction of this topic research, detailed introductions of UWB based on TDOA location algorithm and the UWB positioning algorithm based on RSSI are given. Then, a UWB wireless indoor hybrid localization algorithm based on TDOA/RSSI is proposed. And not only gives a detailed derivation but also studies the position error and the error source of the algorithm. At the same time, the comparation with the proposed algorithm based on TDOA/AOA has been made. In order to make it closer to the Cramer-Rao lower bound, the algorithm is to further improve the indoor positioning accuracy while not increase the complexity of the algorithm under the premise.4. Various single location algorithms and hybrid positioning algorithms under different SNR and different numbers of nodes are simulated by Matlab, and the comparison of TDOA/RSSI hybrid positioning algorithm between other localization algorithms is focused. These results of experiments show TDOA/RSSI hybrid positioning algorithm has higher accuracy than other algorithms.