Synchronization of carrier phase for GNSS signal assessment using variable step

Microwave direct sampling was adopted to avoid nonlinear distortion caused by down-convertor for signal quality evaluation of global navigation satellite system (GNSS). The sampling data number is too large for conversional carrier phase synchronization to realize. A carrier synchronization algorithm using variable step is presented to solve this problem. After the coarse initial phase of carrier has been evaluated using large step, the GNSS signal is stripped carrier and then the synchronization of PRN code was carried out. Finally, a fine phase evaluation of carrier was executed using small step. Simulation results show that the proposed algorithm is practicable and the accuracy of carrier phase synchronization is high. Select the appropriate step, the synchronization error can be less than 0.01 radians for the L-band carrier frequency.