An implementation scheme of GNSS signal simulator based on DSP and FPGA

Global Navigation Satellite System (GNSS) signal simulator plays an important role in designing navigation signal and developing receiver. Traditional GNSS signal simulators are almost implemented based on the combination of software and hardware whereas they are usually complex and costly. In this paper, a GNSS signal simulator is designed based on Digital Signal Processor (DSP) and Field Programmable Gate Array (FPGA). The computation of signal parameters and generation of signal are both implemented in hardware. After the GNSS signal model is presented, the structure of the simulator and the function of each part are introduced. Then the frequency scheme used in system is analyzed. Finally, the generation procedures of primary Pseudo Random Noise (PRN) code, secondary PRN code, navigation data and the method of chip shaping are illuminated in detail.