Parallel transmission of TDMA synchronization and data bursts by artificial selective threading and decoupling with decision feedback

摘要

A data burst is modulated on an IF carrier, and a spectral null is artificially created in the center frequency region of the spectrum of the modulated data burst by taking the difference between delayed and non-delayed versions of the IF data burst. A sync burst is modulated on the IF carrier so that its spectrum corresponds to the center frequency region of the data burst and superimposed on the IF data burst and transmitted. At a receive site, the IF sync burst is recovered by passing the superimposed IF signal through a bandpass filter having a passband corresponding to the spectrum of the IF sync burst and the IF carrier is recovered from the recovered sync burst. The sync burst at baseband frequency is recovered from the IF sync burst by a demodulator using the recovered carrier. Using the recovered carrier, a baseband sync burst and a baseband data burst having a spectral null are synchronously detected from the superimposed IF signal and fed into a decision feedback equalizer where the original data burst is recovered. IMAGE