专利名称：Signal transmission system and method发明人：Ohashi, Kazuo Yokohama Works of
Sumitomo,Yamakawa, Takuya YokohamaWorks of Sumitomo
申请号：EP85107122申请日：19850610公开号：EP0167850A3公开日：19880928
专利附图：
摘要：A sub-center type switched-star CATV system network in which a number oftransmission signals are transmitted from a central source to a number of subcenters
over a number of sets of optical fibers. In view of the long distances involved, thetransmission signals are transmitted in pulse frequency modulation form, one pulsefrequency modulation signal being applied to each optical fiber. At each sub-center, eachpulse frequency modulation signal is converted into a frequency modulation signal byfirst frequency dividing the pulse frequency modulation signal and then passing thedivided signal through a band-pass filter which eliminates all signal components exceptthe fundamental frequency. The pulse frequency modulated signals may pass through aswitch to select the number of transmission signals which ultimately reach thesubscribers. The frequency modulated signals are then frequency multiplexed toproduce a multiplexed signal and the multiplexed signal is sent to a number of
subscribers. A single optical fiber connects a sub-center with each associated subscriber,respectively. At each subscriber, the multiplexed signal is converted back into theselected number of transmission signals.
申请人：SUMITOMO ELECTRIC INDUSTRIES LIMITED
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