×

Transmitters for burying digital signals within the trace and retrace intervals of NTSC television signals

  • US 5,555,024 A
  • Filed: 09/07/1995
  • Issued: 09/10/1996
  • Est. Priority Date: 12/23/1994
  • Status: Expired due to Term
First Claim
Patent Images

1. A data signal transmitted simultaneously with a television signal through the same television transmission channel;

  • said television signal comprising a video carrier the amplitude of which is modulated in accordance with a video signal descriptive of the scanning of a succession of image frames as scanned one scan line after another at a prescribed video line rate, or scan line frequency;

    said image frames occurring at a prescribed video frame rate;

    said data signal modulating a data carrier having a frequency differing from that of said video carrier by a prescribed frequency offset, and having no image on the other side of said video carrier;

    said data signal having a symbol rate that is a multiple of said prescribed video line rate, having data frames occurring at a data frame rate that is the same as said video frame rate, and customarily having each of the symbols in said data signal that are transmitted in each of alternate data frames being transmitted again but in opposite phase during the next data frame.

View all claims
  • 0 Assignments
Timeline View
Assignment View
    ×
    ×