High Performance Digital Carrier Tracking Loop Design for High Dynamic GPS Receiver

A high efficiency carrier tracking loop to deals with high dynamic circumstance GPS receiver was presented in this paper. Based on FFT parallel capture method, fast frequency discrimination and its realization scheme are studied. We proposed a non-linear carrier NCO unit to track precisely by selecting interpolating filter orders. The carrier tracking is performed by the interpolating filter, which is derived from the frequency discriminator. As usual, carrier correction could be performed by phase rotating, and research shows three-order interpolation filter should give high tracking accuracy. We also put forward a signal processing architecture combined DSP and FPGA deeply studied base-band parallel processing technology in GPS receiver. The simulation demonstrates that the digital frequency tracking loop has high performance on tracking precision, acquisition and enable fast seeking ability in frequency zone under high dynamic circumstance.