ENCODING AND DECODING METHODS FOR HIGH-PRECISION TIME TRANSFER AND ENCODING AND DECODING DEVICES THEREFOR

摘要

A format for modified IRIB-G time code, with added message fields while preserving pulse width coding rule of the standard IRIG-B time code, having a time interval field for carrying time interval between the local time signal and a received time signal, and a user-defined or padded field for carrying user-defined time and/or control messages. An encoding and a decoding methods and devices for high-precision time transfer, where the modified IRIG-B time code carries more messages, and enabling transmission of timing messages and testing messages of two-way time comparison via a single message channel at the same time, which reduces fluctuation due to encoding and decoding manipulation and correlation with working frequencies via exact synchronization between the on-times of the output encoded time code and the transmitted time signal, and between the on-times of the output decoded time signal and the input time code, and improves precision of time transfer.

主权项

1. A format for a modified IRIG-B time code, comprising
frames, each of the frames comprising
fields of a standard TRIG-B time code,a time interval field,a user-defined or padded field, andan ending code element; wherein first 99 code elements of each of the frames are the fields of the standard IRIG-B time code for carrying the standard IRIG-B time codes; the time interval field starts at a 100th code element of each of the frames for carrying a time interval between a local time signal and a received time signal, the 1st code element of the time interval is the 100th code element of each of the frames and denotes an advance or a delay, with remaining code elements of the time interval denotes a time interval measure value in unit of picoseconds; the user-defined or padded field is subsequent to the time interval field for carrying user-defined time, control messages, or both, with code element ‘1’, ‘0’, or both, filling up a bit of an un-used code element; and the ending code element is a last code element of each of the frames and is fixed as a ‘P’ code element.