Group delay measurement method based on narrow-band spread spectrum signals

The group delay fluctuation of navigation equipment will cause signal distortion, thus bringing on ranging bias, and therfore needs to be measured and compensated. The vector network analyser method commonly adopted cannot satisfy high measuring accuracy and high frequency resolution at the same time; the higher the frequency resolution, the bigger the measuring error. To resolve this problem, a new group delay measurement method based on narrow-band spread spectrum signals is proposed. Theoretical analysis and simulation results indicate that this method can implement high measuring accuracy with any frequency resolution, and the system bias of the method is much less than 0.1 ns.