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. 16, 2023
Filed:
Jan. 03, 2022
Sitrus Technology Corporation, Shanghai, CN;
Mrunmay Talegaonkar, Irvine, CA (US);
Michael Q. Le, Laguna Niguel, CA (US);
SITRUS TECHNOLOGY CORPORATION, Shanghai, CN;
Abstract
A referenceless frequency acquisition scheme locks to an unknown data frequency by feedback of sampled data to a digitally controlled oscillator (DCO). A received data signal is converted to deserialized outputs, then by a phase detector to symbol streams of phase updates. Each symbol stream is converted to a lower rate sum, for which absolute values are computed and periodically summed. Absolute value sums are obtained for each frequency over a range of test frequencies to obtain totals, each corresponding to a different test frequency. A critical value is determined from among the totals. The DCO is set to the test frequency corresponding to the critical value as a coarse approximation for the unknown frequency. In subsequent iterations, proportional feedback to the DCO of lower rate sums of symbol streams is combined with integral feedback of codes representing finer approximations of the unknown data frequency swept over successively narrowing bands, and the DCO is locked to the finest approximation that lies between consecutive codes corresponding to sums having opposite signs.