Shortwave Beacon Source Instruction Data Signal Synchronization And Demodulation

This thesis is based on the engineering background of the beacon of over the horizon radar of HF. In this thesis, the synchronization and modulation of bursty short data communication in HF channel was researched. Under the requirement of the integral system and the characters of HF channel, the frame form of instruction data, in which the radar chirp signal and the instruction data are in the same sequence, was designed. A scheme to use radar chirp signal passing through matched filter to implement quick and reliable bit synchronization was proposed, and some related computer-based simulations was also finished. A way to demodulate 16FSK signal instruction data using average periodogram estimator was presented and its error performance was analyzed under additive white gaussion noise. Finally, a DSP software was developed based on the synchronization and demodulation schemes proposed in this thesis. And the schemes was validated by the experiment results.