US Patent No. 10,169,613


Patent No. 10,169,613
Issue Date January 01, 2019
Title Systems And Methods For Waveform Watermarking
Inventorship Gary M. Graceffo, Burke, VA (US)
Andrew Kowalevicz, Arlington, VA (US)
Assignee Raytheon Company, Waltham, MA (US)

Claim of US Patent No. 10,169,613

1. A device for watermarking a waveform, the device comprising:an overt symbol modulator to receive mapped overt data and provide overt data modulated in accord with an overt data modulation scheme;
a covert symbol modulator to receive mapped covert data and provide, using dither modulation and micro-amplitude modulation, covert data modulated in accord with a covert data modulation scheme;
a clock that operates with a jitter on the order of femtoseconds coupled to the overt symbol modulator and the covert symbol modulator;
a switch to receive the modulated covert data and the modulated overt data and forward the covert data and modulated overt data based on a signal indicating whether covert data is to be transmitted and/or the overt data is to be transmitted; and
transmission circuitry to produce an electromagnetic waveform of the modulated overt data and/or modulated covert data from the switch,
wherein the modulated overt data includes a constellation of symbols and the modulated covert data includes a symbol for every sub-constellation of symbols in the constellation of symbols, wherein the symbol is within a perimeter of the sub-constellation.