Design Considerations for a WARP-Based Real-Time Software-Defined GPS Receiver

This paper presents an architecture for a real-time software-defined GPS receiver based on the Wireless-Open Access Research Platform (WARP) which was developed by Rice University. The hardware options available on the WARP are examined to determine the best interface to a GPS antenna. Since the WARP utilizes a Xilinx Virtex 4 FPGA with embedded PowerPC microprocessor, the design flow for the development of firmware and software for the WARP is presented. The sampling rate considerations, acquisition methodology considerations and tracking methodology considerations are all examined with an emphasis on maintaining real-time performance. For the final computation of the navigational solution, integration with an existing open-source software-defined GPS receiver is proposed.