NON-TAYLOR SERIES BASED POSITIONING METHOD FOR LOCATION BASED SERVICES

Location based services (lbs) has gained increasing popularity in major cities. due to blocking from man-made structures, the existing global positioning system (gps) could not satisfy lbs applications, especially in street canyon and indoor surroundings. this has lead to the development of assisted gps (a-gps) which can provide better service availability and accuracy gain. in the conventional positioning method, taylor series expansion is applied to solve non-linear distance equations. this method requires an initial estimation of a-gps receiver’s position. this paper investigates the positioning method for lbs based on hybrid e-otd/gnss. the proposed positioning method is non-taylor series based. therefore, it involves less complicated mathematical expansion and substitution. a flexible lbs positioning tool is developed which can generate position information in convenient way. it supports both taylor series and non-taylor series based positioning methods. the obtained results showed that the proposed non-taylor series based positioning method can achieve better positioning accuracy.