With the development of the third-generation Beidou system (Beidou-3), the new generation B1C and B2a signals have been transmitted, which have many characteristics such as BOC/QMBOC modulation types and data/pilot channel structures. This paper firstly reviews the signal properties of B1C and B2a, including the transmit power, the tracking and observation noise. Then, the B1C data/pilot joint tracking are designed by using pseudo-correlation-function based unambiguous tracking technology. In order to reduce the tracking noise and improve the tracking sensitivity and robustness of B1C, the Doppler-aided B1C/B2a joint tracking loop is proposed. A wide bandwidth tracking loop of B2a pilot channel is adopted to tracking the signal dynamics whereas both the B1C data and pilot channels use narrow tracking bandwidth to reduce signal noises and interferences. The traditional and joint tracking loop are compared by the field experiments. Experiment results show that the proposed method can keep tracking under step jamming with a sudden CN0 decrease over 10 dB and also reduce the tracking noise especially for code loop tracking. Moreover, the proposed method can keep tracking at lowest CN0 about 15.68 dB-Hz for B1C data component and 19.58 dB-Hz for B1C pilot component when a fading B2a pilot signal is used as the aiding information, and even keep tracking at lowest CN0 about 9.83 dB-Hz for B1C data component and 15.91 dB-Hz for B1C pilot component when a good B2a pilot signal is used as the aiding information.