P/Y Code pseudolite data link to a military GPS receivers

The proliferation of GPS into weapons systems provides an opportunity to establish a wireless data interface into GPS guided weapons. The proposed design builds on an Open Systems Interconnect (OSI) model to provide a generic network architecture that takes advantage of existing standards in data communication to facilitate integration with the Military Information Structure or C41 network. Under this effort, a preliminary network definition will be established for the GPS uplink comprising the definition of the Mobile End System (or modified GPS receiver), the Mobile Data Base Station (or pseudolite transmitter), the protocols adopted and network interconnectivity. The generic network architecture will facilitate integration of different platforms for broadcasting the data uplink, including ground-based or ship-board pseudolites, and geostationary satellite transponders such as the Inmarsat III payload. The network infrastructure proposed will support multiple users and applications, permitting both broadcast data to multi-user and addressing of specific data to single users. The network approach also offers a solution to the "near-far" problem experienced with point-to-point pseudolite operations by modeling the design on an IS-95 CDMA digital cellular network. As an option, it is proposed to demonstrate the proposed pseudolite data link using NAVSYS previously developed hardware.