Research On Wireless Location Technologies Based On Cellular Network

Location-based service has become one of the most rapidly growing emerging informationindustry following the Internet, mobile communication industry in the international.As avalue-added business service provided by mobile communication network,wireless positioningplays a very important role in our daily life.So the study of the wireless location technology is veryimportant.The main research work includes:(1)The author summarized the positioning technologies in GSM,3G, LTE cellular mobilecommunication system.Also,the author introduced the signal characteristic parameters such as Timeof Arrival (TOA), Time Difference of Arrival (TDOA) and Angle of Arrival (AOA) and theirestimation methods,then he compared the positioning algorithms in different situation.(2)The author summed up the identification of non-line-of-sight(NLOS) transmissiontechniques and some NLOS mitigation techniques.(3)In the paper,the author takes advantage of the Unscented Kalman Filter with someimprovement of previous work to reduce NLOS error in location measurement. One of the keycontributions of this paper is to present the methods that discriminate the NLOS measurements fromLOS measurements based on the standard deviation and K-means clustering and reconstruct theLOS measurements out of the NLOS measurements by polynominal fit in order to mitigate theNLOS error.Simulation results confirm the effectiveness and accuracy of our approach incomparision with the conventional EKF algorithm.The author also had a research on location-basednetwork optimization.Location-based network optimization aims at enhancing network performancein terms of coverage,capacity,energy consumption,etc.He discussed how to use location informationin radio resource management.