Title :
Fast carrier-tracking coherent detection with dual-mode carrier recovery circuit for digital land mobile radio transmission
Author :
Saito, Shigeki ; Suzuki, Hiroshi
Author_Institution :
Radio Commun. Lab., NTT, Kanagawa, Japan
Abstract :
A new type of carrier recovery circuit suitable for coherent detection in digital land-mobile radio transmission is studied experimentally. A dual-mode carrier recovery (DCR) circuit is proposed that adaptively selects one of two phase locked-loop operation modes: the conventional mode or the adaptive carrier-tracking (ACT) mode. The ACT mode digitally controls the reference phase, and enables instantaneous phase tracking in burst signal operation and/or in a fast fading environment. The DCR coherent demodulator performance is identical to that of conventional coherent detection in the low-CNR region, and to that of differential detection in the high CNR region where the ACT mode is selected.<>
Keywords :
demodulators; digital radio systems; mobile radio systems; signal detection; adaptive carrier-tracking; burst signal operation; coherent demodulator; coherent detection; digital land mobile radio; dual-mode carrier recovery circuit; fast carrier tracking; fast fading environment; instantaneous phase tracking; phase locked-loop operation modes; Automatic frequency control; Bit error rate; Circuits; Delay lines; Demodulation; Energy consumption; Fading; Frequency modulation; Land mobile radio; Quadrature phase shift keying;
Journal_Title :
Selected Areas in Communications, IEEE Journal on
