下载

Analyzes the positioning technology based on UWB signals and briefly outlines the basic concepts, definitions and unique advantages of UWB signals. By studying the characteristics of the UWB pulse signal, the signal used to generate the UWB signal is selected, and the corresponding channel model is established, the principle is explained, and the characteristics of the UWB signal in different indoor environments are simulated under the impulse response.For various errors caused by position estimation, including non-line-of-sight propagation, multipath effects, clock drift errors, the causes of the errors are analyzed, and the evaluation index of the positioning algorithm accuracy is given. By comparing the lower limit of Cramer-Rao Lower Bound, the root mean square error or the cumulative distribution function of different algorithms, we compare the advantages and disadvantages of the algorithms. Explained the principles of RSSI, AOA, TOA, TDOA based on different signal parameter positioning algorithm, derived positioning algorithm, derived their respective Cramer-Rao Lower Bound, choose to use positioning based on arrival time (difference) positioning algorithm.The time of arrival parameters in the TOA positioning algorithm are studied. Since ordinary one-way ranging is greatly affected by the clock drift error, the effect of the clock drift error is reduced by improving the ranging method. Different TWR ranging algorithms are proposed, and based on the error model under the IEEE802.15.4a standard, a new error model is established, and new error sources are introduced, such as antenna delay, hardware delay and propagation process delay, etc. The new error model is used to theoretically derive and analyze the ranging errors of different TWR algorithms and compare them with the original error model. From the derivation results, the ALTDS-TWR algorithm can more effectively reduce the ranging errors.For different TWR algorithms, through error models, establish simulation environments in different situations, more targeted analysis of the advantages and disadvantages of different TWR algorithms, compare the errors generated by different TWR algorithms, consistent with the mathematical derivation results, ALTDS-TWR algorithm Compared with other algorithms, the ranging error is minimal.