Integrated GPS/TOA Navigation using a Positioning and Communication Software Defined Radio

While GPS is the natural choice for providing navigation in an outdoors environment, it experiences significant challenges when operating in an urban environment where the GPS signals can be significantly attenuated, often completely blocked, inside buildings or in urban canyons. In this paper a networked radionavigation approach is described that augments the GPS signals with Time of Arrival (TOA) observations using a Software Defined Radio (SDR). Simulation and test results are included to demonstrate the GPS/TOA network-aided positioning solution can be derived.