Universal ranging code generator of GNSS signals

This paper reviews PRN code generation methods. Generated codes are used as ranging codes in the existing GNSSs. These codes are used to improve the accuracy of the ranging measurements. We present the structure of the universal code generator which can be used in the satellite navigation systems: NAVSTAR GPS, GLONASS, Galileo, Beidou. This generator provides the ability to generate ranging codes for almost 70% of all open navigation signals. Universal generator was implemented as a SystemVerilog module as part of the navigation receiver software. Using the receiver including this module, we have successfully received navigation signals that use different PRN codes. We also compared hardware resource utilization by universal generator and by GPS C/A ranging code generator. This analysis showed that the universal generator module uses less than 4 times more FPGA resources than the special GPS C/A generator module. However, the resource utilization of the correlator channel increases by only 5 percent.