A discriminator algorithm and a loop filter structure critically affect the performance of a GPS carrier tracking loop and a receiver.Firstly

from the analysis of the traditional PLL (phase-locked loop) and FLL (frequency-locked loop) discriminators

a new discriminator algorithm is put forward based on a shared four-quadrant arctangent function between PLL and FLL.Secondly

a loop filter design is given based on the boxcar digital integrator by comparison with a digital bilinear transform integrator.Finally

a low complexity design scheme for GPS carrier tracking loop is represented

which is composed of the proposed discriminator and the loop filtering algorithms.The theoretical analysis and simulation results confirm that this novel design has low complexity

less resources and achieves good tracking performance.