05243423 is referenced by 296 patents and cites 10 patents.

A co-channel communication system allows transmission of one or more data signals in an active or visible portion of a video raster in a manner that is imperceptible to a viewer. More particularly, the data signal is transmitted over a preselected active video lines of a video raster. In order to reduce the perceptibility of the data signal, the video lines over which the data signal is transmitted is varied according to a random sequence. In an alternate embodiment, the data is also modulated at relatively low modulation levels, for example, by converting the data signal to a spread spectrum signal.

Title
Spread spectrum digital data transmission over TV video
Application Number
7/811805
Publication Number
5243423
Application Date
December 20, 1991
Publication Date
September 7, 1993
Inventor
Robert Weissman
Westport
CT, US
Daozheng Lu
Buffalo Grove
IL, US
Jean P DeJean
Cincinnati
OH, US
Agent
Marshall O Toole Gerstein Murray & Borun
Assignee
A C Nielsen Company
IL, US
IPC
H04N 7/08
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