| The US Global Positioning System (GPS) and other existing and emerging Global Navigation Satellite Systems (GNSS) receiversincorporated in mobile devices perform very well in strong signal conditions, but their operation in many urban and indoor applications is not robust or even impossible due to multipath, foliage, dissipation, etc. To overcome such situations, extensive research has been done by engineers in recent years resulting in an approach known as Assisted GPS (A-GPS). Using this approach, orbital parameters such as ephemeris, almanac, reference time and coarse location information is provided to the GPS receivers which significantly enhances the acquisition of weak signals. To test A-GPS enabled receivers high-end simulators are used, as they involve additional assistance data generation, GPS signal, positioning measurements, acquisition of coarse location and delivery to target devices. Typically such simulators are not affordable by many academic institutions. National Instruments (NI) GPS Simulation Toolkit integrated with NI RF hardware support provides an efficient testing environment for A-GPS enabled receivers. This thesis describes an economic potential dedicated Labview-based A-GPS Simulator which is integrated with NI's GPS Simulator Toolkit. It also describes the test platform developed for a two-way communication between the A-GPS simulator server and the client mobile device through client/server applications in java environment. Communication between the client/serverhas been realized through Wi-Fi technology and Packed Encoding Rules (PER) which is a standard encoding rule to produce compact transfer syntax. The communication is in accordance with the Secure User Plane Location (SUPL) protocol encapsulated with Radio resource location services (LCS) protocol (RRLP) applies to GSM and GPRS Cellular Networks. |
