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:
Feb. 28, 2006
Filed:
Mar. 28, 2002
Jonathan James Davies, Dorchester, GB;
Shaun Michael Dunn, Dorchester, GB;
Stephen Arthur Pointer, Dorchester, GB;
Samuel William Downer, Dorchester, GB;
Jonathan James Davies, Dorchester, GB;
Shaun Michael Dunn, Dorchester, GB;
Stephen Arthur Pointer, Dorchester, GB;
Samuel William Downer, Dorchester, GB;
Qinetiq Limited, , GB;
Abstract
For digital underwater transmission an information sequence () of digital bits is partitioned into a succession of symbols each comprising n bits where n is equal to or greater than one (2potential symbols), each symbol () is replaced () a corresponding base code sequence of length m bits and the result () is passed to an acoustic transducer after bi-phase modulation () on a carrier. The code has good correlation properties, e.g. a pseudo-random maixmal length sequence, a Gold code or a Kasami code, and the value of m/n is at least (32). Preferably the base sequence is cyclically extended at one or both ends prior to modulation, and Solomon Reed redundancy coding () is initially applied to the information sequence. The output () of modulator () may be prefaced () by a pair of chirp waveforms (). Provision is made for Doppler and multi-path correction.