NETWORK SYSTEM USING TV CHANNEL DATA TRANSMISSION SCHEME,申请号WO1998US04804-传众专利搜索

NETWORK SYSTEM USING TV CHANNEL DATA TRANSMISSION SCHEME

申请公布号：WO9841018(A1)

申请号：WO1998US04804

申请日期：1998.03.11

申请公布日期：1998.09.17

申请人：

HYBRID NETWORKS, INC.

发明人：LEVAN, WILLIAM

分类号：H04L5/06;H04L7/027;H04N5/44;H04N5/455;H04N7/035;H04N7/08;H04N7/081;(IPC1-7):H04N7/08

主分类号：H04L5/06

摘要：A system utilizes a unique modulation system that enables the transmission of digital data over wireless, cable or direct satellite TV channel without disturbing quality of television signals. A data stream is transparently transmitted in the TV channel in a superfluous sideband segment of the frequency spectrum using a technique herein called vestigial quadrature modulation (VQM), that entails substituting the vestigial sideband of a conventional TV signal with a sideband of a data-encoded signal, preferably being QAM-modulated. A portion of the sideband spectrum is preserved for deriving sync information that is used for both clocking the digital data from the modulated data signal and for deriving vertical and horizontal sync circuits of the television. A receiver (100) in a network terminal device utilizes an interface that includes a channel splitter (108) and SAW filters (112, 114) in each of respective data and video channels for separately processing the video and digital data channels.