| With the continuous development of science technology, positioning and navigating by multiply satellite systems is playing an increasingly important role in both civil and military use.This article introduces a design scheme of navigation receiver system, based on the frame of ARM and FPGA in hardware and software, and the fusion of three satellite systems is brought out by combing the frequency points of L1in GPS, L1in GLONASS and B1in BDS.The RF front-end adopts MAX2769chip from MAXIM Company, while FPGA and ARM adopt XC6SLX150chip of Spartan-6series from Xilinx Company and LPC3250chip of ARM9core from NXP Company.Three MAX2769chips are dealing with down-converting and sampling satellite signals in these three frequency points. There is a Fast-Acquisition engine designed independently and Track engine consisting of three-order PLL aided by two-order FLL in FPGA, and thus FPGA can deal with acquisition and track of satellite signals. Resolving position and navigation scheme can be implemented in ARM, because of floating-point coprocessor inside, which enormously enhances the ability of calculation on floating-point numbers. After testing, the precision of positioning, velocity measurement and time service has been confirmed to come up to the expectations. In addition, receiver based on ARM has merits of low expense and power consumption. |
