A Novel Coherent Preambleless Demodulator Employing Sequential Processing for PSK Packet Signals--AFC and Carrier Recovery Circuits--

Takeshi ONIZAWA  Kiyoshi KOBAYASHI  Masahiro MORIKURA  Toshiaki TANAKA  

IEICE TRANSACTIONS on Communications   Vol.E82-B   No.3   pp.542-550
Publication Date: 1999/03/25
Online ISSN: 
Print ISSN: 0916-8516
Type of Manuscript: PAPER
Category: Mobile Communication
packet,  AFC,  preambleless,  phase signals,  sequential,  carrier recovery,  sample hold,  

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This paper proposes a novel sequential coherent preambleless demodulator that uses phase signals instead of complex signals in the automatic frequency control (AFC) and carrier recovery circuits. The proposed demodulator employs a phase-combined frequency error detection circuit and dual loop AFC circuit to achieve fast frequency acquisition and low frequency jitter. It also adopts an open loop carrier recovery scheme with a sample hold circuit after the carrier filter to ensure carrier signal stability within a packet. It is shown that the frame error rate performance of the proposed demodulator is superior, by 30%, to that offered by differential detection in a frequency selective Rayleigh fading channel. The hardware size of the proposed demodulator is about only 1/10 that of a conventional coherent demodulator employing complex signals.