BPM short-wave data modulation design method based on Chirp signal

Abstract

The invention provides a BPM short-wave data modulation design method based on a Chirp signal, which combines the Chirp signal and MFSK to form a multi-ary Chirp signal center frequency keying (MCFSK)mode, thereby not only retaining the advantages of MFSK, but also further improving the ability of system data transmission to resist short-wave channel interference. In addition, MCFSK is cascaded with binary Chirp-rate keying to form MCFSK-2CrSK modulation, which can improve the system data transmission rate without changing the MCFSK modulation signal parameters. The invention may be compatible with the existing BPM short-wave timing system without affecting the use of the original system user. The data modulation signal provided by the invention has the advantages of good anti-multipath fading and anti-Doppler frequency shift, is suitable for the short-wave channel, and may be flexibly designed for channel characteristics and synchronization accuracy of the receiving terminal.

Description

technical field [0001] The invention relates to the technical field of communication and information processing, in particular to a BPM shortwave data modulation design method. Background technique [0002] As one of the large scientific installations, the BPM short-wave timing system is a long-distance land-based radio timing service system independently mastered by my country, and it is also the only means for the broadcast of my country's universal time correction (DUT1). The BPM short-wave time service system alternately broadcasts standard time and standard frequency signals at 4 frequencies (2.5MHz, 5MHz, 10MHz, 15MHz) every day. The content of the broadcast includes the UTC time number of the coordinated universal time, the UT1 time number of the universal time, empty carrier and BPM call sign. BPM timing broadcast program: (1) 59 m 00 s ~00 m 00 s and 29 m 00 s ~30 m 00 s Broadcast BPM callsign; (2)00 m 00 s ~10 m 00 s 、15 m 00 s ~25 m 00 s 、30 m 00...

AI Technical Summary

Problems solved by technology

The main problems existing in the existing time code insertion scheme: (1) the data rate is low, only 1bps, and it takes 1 minute to broadcast a complete time code information, and the risk of being interfered by the shortwave channel is very high; (2) there is no time code frame format Sufficient reserved extension bits make it difficult to implement system expansion applications; (3) Without reliable verification, it is difficult for the receiving terminal to judge the accuracy of the received time code information

Images