Oct. 28, 2009, by making use of the transmission interval of transmission system of Shangqiu Low-Frequency Time-Code Time Service Station, the low-frequency time-code project group of NTSC conducted an experimental verification on key technologies in low-frequency time-code system plus spectrum spread time service and achieved success.
Low-frequency time-code time service technology is modern and encouraged by International Telecommunications Union (ITU). Electric wave horologe, as one of its terminal products, is called a new-generation timing device that can replace quartz horologe. The year of 2007 has witnessed the establishment of low-frequency time-code time service station in Shangqiu, Henan by NTSC for continuous transmission with the call sign as BPC. The low-frequency time-code system plus spectrum spread time service method is raised by Wu Guichen and Feng Ping, which can largely strengthen the anti-jamming capability of low-frequency time-code time service receiver and is conducive to the improvement of time service precision. Among these technologies, such key technologies as “phase control technology of high-power solid state combined transmitter”, “feedback of aerial system to transmission system made by sudden change of carrier phase” need to be verified by experiment.The Low-frequency time-code project team has performed research design preparation for relevant experiments in Mar. and has completed the development preparation for various instruments and testing equipment in Oct this year. The experimental verification on high power transmission system shall first not affect the normal trial transmission of Shangqiu Low-Frequency Time-Code Time Service Station and second ensure the safety of current operating system. On the basis of joint experiment commissioning, researchers finally come out applicable method through repeated attempts and experiments. The experiment was conducted on Oct 28 in accordance with the pre-scenario and was proved successful. It shows that the technical scenario for low-frequency carrier-wave plus spread spectrum time service designed by the Center is completely applicable.
The success of key technology experiment on BPC low-frequency time-code system plus spread spectrum time service has provided important technical support for a new-generation low-frequency time-code time service system integrating various information technologies and has significant application value for further exploring the low-frequency time-code time service technology.