Software-only TDOA/RTF positioning for 3G WCDMA wireless network

A hybrid location finding technique based oil time difference of arrival (TDOA) with round-trip time (RTT) measurements is proposed for a wideband code division Multiple access (WCDMA) network. In this technique, a mobile station measures timing from at least three base stations using user equipment receive-transmit (UE Rx-Tx) time difference and at least three base stations measure timing from the mobile station using RTT. The timing measurements of mobile and base stations are then combined to solve for both the location of the mobile and the synchronization offset between base stations. A software-only geolocation system based on the above mobile/base stations timing measurements is implemented in Matlab platform and the performance of the system is investigated using large-scale propagation models

An indoor positioning system based on global positioning system

GPS (Global Positioning System) has great demand in recent years and the use of GPS has increased widely in many areas like transportation, tracking, navigation, as well as being implemented in almost all of the smart phones for location based services to improve the quality of our daily life. GPS system communicates with the satellites which send the GPS signals to the earth to be able to provide needed information to the GPS receivers. GPS signals that reach to the earth is in low power and GPS receivers evaluate the position with respect to information in the signal. This position evaluation can be done with the error of 2.5 meters in today's technology. Despite this system is successful in outdoor areas, it is not so successful in indoor areas. Decoding GPS signals in the indoor areas is hard due to additional loss in the GPS signal because of interaction of the signals with physical obstacles. There is a need for increasing coverage of GPS signals in indoor areas like tunnels, undersea and buildings. In this thesis, an indoor positioning system based on GPS infrastructure is proposed and designed. Designed indoor positioning system consists of directional GPS antennas, downconverters, upconverter and IF antennas. For realizing the system, downconverters, upconverter and IF antenna are designed, manufactured and measured. The experiments show that indoor positioning can be done with our designed system by adding some hardware and updating in positioning algorithm to the conventional GPS receivers