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:
Sep. 19, 2006
Filed:
Apr. 09, 2002
Applicants:
Jingdong Lin, Irvine, CA (US);
Justine Zhuang, Shanghai, CN;
Tong Zhao, Stanford, CA (US);
Inventors:
Assignee:
Spreadtrum Communications Corporation, Sunnyvale, CA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H03D 1/00 (2006.01); H04L 27/06 (2006.01);
U.S. Cl.
CPC ...
Abstract
A method of detecting a tone signal from complex input samples r(n) in a wireless communication system is disclosed. The method comprises calculating the phase difference of the samples r(n) as a signal x(n). Next, the signal x(n) is filtered with a notch filter to generate a notched output y(n). The power of both the signal x(n) and the notched output y(n) is estimated. The ratio of the powers of the notched output y(n) and signal x(n) is calculated. The tone signal is detected if the ratio is below a predetermined threshold for a predetermined duration of time.