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Carrier-aided code tracking loop is widely used in satellite navigation receivers. This kind of loop structure can reduce code tracking noise by narrowing the bandwidth of code tracking loop. The performance of carrier-aided code tracking loop in receivers is affected by frequency deviation of reference clock source. This paper analyzes the influence of carrier frequency offset and sampling frequency offset on carrier-aided code tracking loop due to reference clock offset. The results show that large frequency offset can cause code tracking loop lose lock, code tracking loop is more sensitive to sampling frequency deviation and increasing the loop bandwidth can reduce the effects of frequency offset. This analysis provides reference for receiver tracking loop design.

An array antenna calibration method using satellite navigation signal is proposed. Through tracking satellite navigation signals received by different antenna elements, the amplitude and phase calibration parameters can be derived from signal power and carrier phase which are extracted from signal tracking loop. Simulation results show that using the calibration results based on GNSS signal in beamforming can get C/N0 gain almost the same as calculated from theory. The calibration method is simple and fast, thus can be easily embedded in GNSS receivers using array antenna.