04196310 is referenced by 178 patents and cites 8 patents.

A secure information broadcasting system including a central transmitting station for encoding data in binary form utilizing a keyword and transmitting a FM-SCA signal phase shift modulated by the encoded data. Each of a plurality of portable receiving terminals has an identification number stored therein. When a subscriber desires to display the broadcast information on his terminal, he enters a unique password which is combined with the identification number to generate the keyword. The keyword is utilized to decode the received binary data. The portable terminal includes a receiver for decoding the phase shifted FM-SCA signal into the encoded binary data; a keyboard for entering the password, information and display commands; an alpha-numeric data display; a processor responsive to the inputs from the receiver and the keyboard for performing selected arithmetic and logic operations to generate output data to the data display and a bus connecting the circuits of the portable terminal for parallel signal flow.

Title
Secure SCA broadcasting system including subscriber actuated portable receiving terminals
Application Number
675504
Publication Number
4196310
Application Date
November 3, 1977
Publication Date
April 1, 1980
Inventor
John F Schultz
Gainesville
FL, US
Charles A Schultz Jr
Gainesville
FL, US
Aubry S Forman
Toledo
OH, US
Agent
Wilson Fraser Barker & Clemens
Assignee
Digital Data
OH, US
IPC
H04I 9/02
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