Low frequency time-code time service method based on frequency sharing
Ping Feng, Zhiyong Zhang, Guichen Wu, Yan Bai, Xiaofeng Ding · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2013
Low frequency time-code timing service is an important mode in the modern timing system. Low frequency time-code timing radio station (BPC) is built by National Time Service Center in China. Based on the modern signal characteristic of BPC, a new timing method based on frequency sharing is presented, which is the additional spread spectrum modulation timing method in idle carrier wave of BPC. The rationale of the additional spread spectrum modulation timing method in BPC is researched. The performance of the method is analyzed. The research results indicate that the coverage of low frequency signal can be enlarged by the additional spread spectrum modulation timing method, and the timing precision of BPC will be enhanced. So low frequency time-code timing service can be used broadly.