Study Of Accurate Location Algorithm In Cellular Location System

With the rapid advancement of telecommunication technology, Cellular Location System has become a very hot researching field. Lots of achievements are accomplished these years in laboratories as well as in real life application. With in several kinds of location techniques, Time Difference of Arrival (TDOA) based method would be the most widely used one in location system. So far, TDOA method and its relating estimation technologies have drawn more and more attention.This paper mainly investigates four important aspects in realization of a TDOA based cellular location system.1. In order to fulfill the location service need of a metropolis, the framework design of a cellular location system is provided. The fundamental direct sequence spectrum spread system, which sustains the location technology, and the improvements of such system are studied.2. Starting from the basic white noise sequence, the paper evaluated the performance of different location signal sequences, and introduced how to generate a sequence suitable for location application.3. The paper studied several algorithms in TDOA estimation. Emphasis has been placed at General Cross Correlation method. Simulations and enhancements are provided. The problem of multipath fading in TDOA estimation and the super-resolution algorithms used to tackle the problem are also investigated.4. The closed-form of hyperbolic location estimation algorithms are derived and evaluated, which include direct method, LE algorithm, Chan algorithm, and AML algorithm.