The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 31, 2021
Filed:
Jun. 01, 2020
Raytheon Company, Waltham, MA (US);
David D. Crouch, Eastvale, CA (US);
James J. Richardson, Temecula, CA (US);
Walter M. Golonka, Diamond Bar, CA (US);
Raytheon Company, Waltham, MA (US);
Abstract
Covert acoustic communications (CAC) through solid propagation channels that connect node pairs is achieved by encoding signals using spread spectrum coding techniques that position the encoded signal at a center frequency fwithin a narrow frequency bandwidth BWin which the amplitude of the channel response H(f) between each node pair is relatively high. The channel response H(f), bandwidth BWand center frequency f, and accordingly the signal data rate will adapt for each node pair and possibly each side of the node pair. A pre-distortion filter 1/H(f) pre-distorts the encoded signal over bandwidth BWto compensate for material and modal dispersion and multipath between the node pair. This technique avoids the problems associated with frequency dependent attenuation of the continuous solid path and allows for simultaneous transmission and reception of signals among the multiple node pairs.