Uwb Indoor Positioning

Ultra-wide band(UWB) techniques have been the focus of much research and development because of its unique characteristics, especially following the approval of the UWB techniques by the FCC(Federal Communication) in February , 2002. And it also results in an increasing research in UWB applications. UWB impulse radio technique makes use of ultra-short duration pulses, which yields ultra-wideband signals characterized by extremely wide frequency band and extremely low power spectral densities. UWB techniques can arrive at the request of the indoor location techonogy in virtue of the good abilities of anti-detection, low power consumption, potentially immunity to multipath fading and so on. This thesis mainly studies the indoor locationing based on UWB techniques.In this thesis, Some systematic research work on the pirotal technology of wireless positioning has been done after referring to many classic or new naterials. An entire location process normally consists of two steps. Firstly, the related parameters, such as TOA(time of arrival) or TDOA(time difference of arrival) or AOA(angle of arrival), are distilled from the received signals by BS(Based Station) with the help of the parameter estimation algorithms; and the second step determines the MS(Mobile Station) position using appropriate positioning algorithms, based on the available location parameters.This thesis has studied the classics localization algorithm, including: Fang algorithm,Chan algorithm and Taylor algorithm, then has carried on the simulation to them. Non Line of Sight (NLOS) propagation caused by the severe wireless channel,and the solution to the nonlinear equations are affect the localization performance two crucial factor. so the above classics the localization algorithm will be unable to be used directly. This article has mainly studied in the anti-NLOS enor algorithm the wireless localization technology, and analyzed the influence to the TOA/TDOA localization algorithm caused NLOS multipath propagation.Based on the studies about classical algorithm under the line-of-sight (LOS) environment, this thesis proposed an hyrid location method. Considering the characteristic of ultra-wide band indoor localization, an improved location-error weighted algorithm was proposed. The simulationresults shows that the improved method has obtained the better positioning accuracy.