中文摘要：

用户在利用中国BPL长波授时技术时，首先需要粗同步，然后才可以得到精确时间信息、介绍当前常用的罗兰-C数据链调制方式．提出了一种BPL时码信号调制方法及编码格式，从而使BPL具有自主授时功能，更好地为用户服务．

英文摘要：

Before get the precision time signal, the users of BPL time signals need ‘initiative synchronization＇. In this paper, Loran-C datalink is introduced and the suggested method of BPL time code modulation is recommended, which would offer more effective time service.