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:
May. 27, 1986
Filed:
May. 04, 1984
Hiroshige Fukuhara, Yokosuka, JP;
Abstract
In a loran-C radio receiver, tracking of the loran-C signal is initiated by sampling the carrier wave intensity of the loran-C signal at a high frequency over two pulse modulation cycles of the loran-C signal and storing the values recorded in each cycle of the sampling frequency in a corresponding memory cell. The sampled values are stored by adding one to the corresponding memory cell if the sampled signal polarity is positive and subtracting one from the given cell, which is initialized to a known value, when the sample has a negative polarity. This sampling over two loran-C cycles is then repeated numerous times, so that after such repetion, each memory cell, corresponding to a specific phase of the loran-C signal, will either have the known value, indicating no carrier wave peak, or a value significantly greater than the known value, indicating a carrier wave peak and so a loran-C pulse. Coordination between the carrier wave and the sampling process is achieved by a multiple sample pulse with a period matching that of the carrier wave, each pulse of the multiple sample pulse being separate from others by 1/4-or 1/8-of the carrier wave period and the first of the multiple pulses being synchronized with a zero-crossing point of the carrier wave.