Performance evaluation of a high-precision timing receiver based on the BDS-3 PPP-B2b service

    The precise point positioning (PPP) timing service has been proposed in recent years and has been demonstrated to achieve sub-nanosecond accuracy. As an integral part of BDS-3, the PPP services via b2b signals (hereafter referred to as PPP-B2b) are provided by BDS-3 GEO satellites with better than decimeter-level accuracy for users around China. In this research, a high-precision timing receiver based on the BDS-3 PPP-B2b service has been established, which obtains the local clock offset with respect to Beidou Time (BDT) through PPP time transfer, and controls the local clock of the receiver according to the clock offset. The 1PPS output of the receiver clock is adjusted to the BDT.

    First, the performance of the time transfer is evaluated. The experimental results of two links show that a level of 0.20 ns can be achieved with a convergence time of 20 minutes. Second, the timing performance of the receiver is examined using UTC(NTSC) as a reference. The timing accuracy is better than 0.2 ns in terms of standard daily deviation, and the frequency stability could reach about 2 × 10-14 in 1 day. Third, we compare the time synchronization performance between two receivers using rubidium and a crystal oscillator as the external clock, respectively. When the average time exceeds 10s, the time variance and the Allan variance of the scheme using rubidium clocks is better than the scheme using crystal oscillators.