FPGA-based GPS Correlator Research and Implementation

FPGA-based GPS Correlator with fully independent intellectual property was developed by means of EDA Technology and FPGA Technology.The module of C/A code generator generated three outputs: an early code,a late code,and a prompt code.Using the three outputs,the parallel correlation was developed and it provided the pre-detection data for tracking the GPS signals.The modules for generating measurement data was mainly designed such as the carrier NCO phase,carrier cycle count,code phase and epoch count and so on,and GPS correlator containing this module can be used on the GPS receiver for navigation and survey.The design of all the modules of GPS correlator were studied and all the designs of GPS correlator were implemented in VHDL.The design got verification in Xilinx Virtex-II Pro development board after doing function and timing simulation under the environment of Modelsim software.The results demonstrate that the GPS correlator can incorporate with microprocessor to realize GPS Receiver Baseband Signal Processing.