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The paper presents a scheme of high dynamic GNSS digital receiver using FPGA xc4vsx55 of XILINX and DSP
TMS320VC6701 of TI as core controller. Besides brief introduction of scheme design and hardware structure, the paper
comprehensively introduces design and implementation of algorithms of fast acquisition and tracking of spread spectrum
signal in high dynamic environment. Through optimized design, fast acquisition and tracking of both C code (coarse
ranging code) and P code (precision ranging code) are realized in one chip of FPGA, under the control of DSP.
Employing FFT-based fast acquisition algorithm, acquisition unit realizes the fast acquisition by duplicated using two
FFT/IFFT units with time-sharing fashion, and other optimized FFT calculation structures. Carrier tracking loop is
realized by adopting FLL+PLL method which using FLL tracking carrier Doppler shift with greater bandwidth making
loop closed rapidly and using PLL precisely tracking carrier phase so as to achieve perfect tracking effects. PN code
tracking loop is realized by using multiple non-coherent DLLs with various correlation spacing, which satisfying the
requirements of larger tracking range as well as higher tracking precision by using broad spacing accomplishing initial
tracking and narrow spacing realizing high precision tracking.
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