A Portable GPS Signal Simulator Design Based on ZYNQ

Abstract

Aiming at the problems of a large volume, high price, and complex operation of traditional global positioning system (GPS) signal simulator, a low-cost and portable GPS signal simulator based on ZYNQ is designed, which can simulate and generate multiple satellite signals. Compared with the common digital signal processing (DSP) and field programmable gate array (FPGA) combination technical solutions, ZYNQ adopts ARM + FPGA mode. In this mode, ARM and FPGA can achieve efficient coupling through an advanced extensible interface (AXI) on-chip bus interface, with a faster communication speed and more stable data transmission. The ARM module is responsible for receiving the scene information sent by the host computer as the information processing part, and generating the navigation message in the real time. The FPGA module is used as the signal processing part to process the data of multiple satellites in parallel. The intermediate frequency (IF) signal is modulated by the direct digital synthesis (DDS) technology and sent to the digital-analog converter (DAC) to generate the analog IF signal. The experimental results show that the GPS LI frequency satellite signal is successfully simulated, and the error between the positioning coordinates and the preset coordinates is within a reasonable range, which verifies the feasibility of the design scheme.