Location determination in WiBro (wireless broadband) system

In this paper, TOA(Time of Arrival) measurements from the received signals strength of a WiBro(wireless-broadband) communication system. NLOS mitigation algorithm is applied to solve the navigation problem in the case that under the environments that each BS(base station) have NLOS((Non-Line-of-Sight) error. TOA measurements are known to have poor accuracy due to technical limitations of a communication system and propagation environments. The major error source of TOA is the NLOS. NLOS propagation error occurs when a direct LOS(Line-of-Sight) path between an MS(Mobile Station) and a BS(Base Station) is blocked by some obstacles. To mitigate the NLOS error in a wireless communication network, NLOS mitigation algorithm [5] special GLE is used for each BS channel. Field tests are conducted to evaluate the performance of the NLOS mitigation methods in the urban area in Korea. Using a commercial WiBro cellular phone and a DM tool and are used. Test results show that the NLOS mitigation methods continuously provide subscribers a reasonably accurate location in the case that under the NLOS environments.