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:
Mar. 14, 2000
Filed:
Jan. 24, 1997
Oki Electric Industry Co., Ltd., Tokyo, JP;
Abstract
A digital demodulator compensates for frequency offset between modulated and unmodulated carrier signals by detecting the frequency offset during a preamble with a known modulation pattern. Samples obtained during the preamble are stored in a memory during clock recovery, and read from the memory after the recovered clock signal has become stable. Phase offset is detected from a histogram of the phase differences between the two carrier signals, calculated modulo a certain phase angle, and compensation for phase offset is applied. The maximum histogram value is found by comparisons made according to a single-elimination tournament plan. In a diversity receiver, the maximum histogram value is used to select the output data.