| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a distortion and noise canceling system for HFC network, capable of canceling and removing distortions and noise components of a signal, generated and accumulated in a hybrid fiber-coax (HFC) network. <P>SOLUTION: A distortion and noise canceling system transmits an optical signal from the input side of an optical network unit (ONU) 108 of an existing HFC network to a coaxial distribution hub 112 through a separate optical fiber jumper (optical cable 120); converts the optical signal into a distortion and noise-free radio frequency (RF) signal; extracts only the distortions and noise components by combining the converted distortion and noise free RF signal with a distortion and noise containing RF signal, in opposite phase, while passing through coaxial cables 110 and multi-stage coaxial trunk-line amplifiers 114 in an HFC network; cancels out the distortions and noise components, by combining the extracted distortion and noise component with the distortion and noise containing RF signal, in opposite phase by a distortion and noise canceling section 122, thereby improving signal transmission properties. <P>COPYRIGHT: (C)2009,JPO&INPIT |
