Improved Methods For UWB Indoor Positioning Based On Channel Quality Evaluation

With indoor environment gets more complex,and demands for indoor positioning increase,high-precision and high-reliability indoor positioning technology is concerned by both industry and academia.UWB(Ultra-Wideband)positioning,which is widely used in high-precision positioning scenarios,still has a problem of accuracy decreasing in complex indoor environments.This thesis proposes a method for channel quality evaluation and anchor nodes selection based on channel statistics,which can effectively improve UWB indoor positioning accuracy.The main contents of this thesis are as follows:The basic theory and technology of UWB indoor positioning are studied,considering NLOS(Non-line-of-sight)error as the most important factor which affects the indoor positioning accuracy,so the following study focus on the channel characteristics under NLOS conditions to improve the indoor positioning algorithm in positioning stage.The principle of using UWB PHY in accordance with IEEE802.15.4 standard for channel measurement and UWB channel model is analyzed.The deterministic and the IEEE802.15.4a standard statistical UWB channel model is simulated,the characteristics of CIR(Channel Impulse Response)under NLOS conditions is analyzed.An analytical method is proposed to extract features from CIR to calculate channel quality and select anchor nodes.Simulation and experiments show that the channel quality can effectively characterize ranging reliability and can also be used to distinguish NLOS/LOS(Line-of-sight),experiments show that anchor nodes with higher channel quality for positioning can effectively improve the accuracy.The RMSE(Root Mean Squared Error)decreases by 45.05% on average and 80.95% at most.