Phase synchronization in a satellite‐mobile channel
作者:
Jose M. Riera Salis,
Luis Mercader Del Rio,
期刊:
International Journal of Satellite Communications
(WILEY Available online 1995)
卷期:
Volume 13,
issue 1
页码: 1-10
ISSN:0737-2884
年代: 1995
DOI:10.1002/sat.4600130102
出版商: Wiley Subscription Services, Inc., A Wiley Company
关键词: phase synchronization;LMSS;third‐order PLL
数据来源: WILEY
摘要:
AbstractThis paper studies several aspects relevant to the design of phase synchronization circuits for land mobile satellite systems (LMSS). First, the results of a propagation experiment are presented, with special focus on the effects of vehicle mobility on the signal phase. It is found that the changes of speed and direction cause frequency variations that can be modelled as linear. Bounds for the frequency derivative are given for different percentages of time. The use of third‐order PLLs is considered, as they are optimum for tracking a frequency ramp embedded in white Gaussian noise. The model of third‐order PLL employed is presented, as it is an original model, developed by the authors. Then the performances of second‐ and third‐order PLLs are compared. Theoretical, as well as simulation, results are given. It is shown that third‐order loops give better performance in the presence of frequency variations of the kind observed in this link, but they suffer from a higher sensitivity to oscillators' phase noise. Several conclusions regarding the use of third‐order loops in future systems ar
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