Research On Relay-based Wireless Location Technologies

As one of the key technologies for future wireless systems, the relay can improve the overall efficiency in the network and throughput of system effectively. With which relay brings, the LTE interference within the cell becomes much more complicated. Therefore, the main concern right now is how to use the relay equipment to serve the LTE locating.Firstly, three currently required methods on3GPP are discussed in this thesis. Then, different types of factors which affect the locating accuracy are analyzed, and the methods of reducing the effect are summed up.Secondly, all kinds of locating reference signals from the point of view of designing for locating reference signals are discussed, and the advantages and disadvantages are compared. Then the methods commonly used in wireless location parameters’ estimation which include TOA, TDOA and AOA are described. Also, the time-delay estimation based on generalized cross-correlation method is underlined, the features and performance with different weighting functions in the simulation are composed and analyzed. Then the Chan method, Taylor method, Fang method based on the TDOA are analyzed in depth, and the evaluation methods for locating performance are discussed in detail.Thirdly, the research of wireless locating technology with relay is focused on, and the influence which relays make of the locating system is simulated and analyzed. With the condition of different location method, simulations of the relay involved in participating in the locating or not are analyzed, which gives a conclusion that the accuracy of locating will be improved by the locating system participated by relay combined with Chan method.Finally, conclusions are made in this thesis, and the development of LTE location is prospected.