A window and carrier-frequency synchronization scheme for ST-DFT-based FSK demodulation in LEO satellite communications
Attapol Wannasarnmaytha, Shinsuke Hara, Norihiko Morinaga · Electronics and Communications in Japan (Part I Communications) · 2000
This paper proposes a scheme based on the short-term discrete Fourier transform (ST-DFT), as an FSK demodulation method suited to a low-earth-orbit satellite communication channel with time-varying frequency offset. This demodulation system has the feature that the hardware configuration is simple, but an effective detection window synchronization scheme must be established since the bit-error rate (BER) is greatly affected by detection window synchronization in the receiver. This article proposes a detection window synchronization scheme for the FSK demodulation method based on ST-DFT. Using the proposed detection window synchronization scheme, the optimal detection window timing and center frequency are simultaneously estimated. In addition to the detection window synchronization scheme, this article proposes two methods for adaptive tracking of the time-varying center frequency. The BER performances of the proposed methods in the channel with frequency offset are evaluated by computer simulation. © 1999 Scripta Technica, Electron Comm Jpn Pt 1, 83(4): 73–82, 2000