In recent years, block demodulation systems have been proposed which store blocks of phase‐shift keying (PSK) signal and derive data by batch processing. In such systems the traditional method of realtime demodulation is not considered and block processing is applied after quasicoherent demodulation. Training signals required for traditional methods are not at all needed for this system. Therefore, the data transmission efficiency becomes very high. However, conventional block demodulators have a serious disadvantage–they cannot demodulate the signal without external timing information. This paper proposes a new timing extraction circuit not contained in a conventional block demodulator, which improves greatly practical applicability. Also, a method is proposed for accurate carrier estimation. According to computer simulation results, the permissible noise limit becomes 4 to 5 dB lower in comparison to the conventional method.
|Electronics and Communications in Japan (Part I: Communications)
|Published - 1989 7月
ASJC Scopus subject areas
- コンピュータ ネットワークおよび通信