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. 03, 2002
Filed:
Sep. 21, 1998
Kenji Nowara, Tokyo, JP;
Advantest Corporation, Tokyo, JP;
Abstract
In a measurement of a quality of a CDMA signal diffused by a long code and a short code, the measurement can be performed even if a carrier frequency error is relatively large. A received signal is converted to a complex base band signal s ( ) and a symbol point of the signal extracted ( ). A frequency error &Dgr;f is obtained from a phase slippage from the signal point ( ). The signal s is corrected by the &Dgr;f and the corrected signal s′ is decoded by a diffusion signal of each channel. Also each power is obtained and each reference signal is created. A delay time &tgr; is obtained from each reference signal and the signal s′ such that a square error &egr; between them is minimized ( ). The signal s′ is corrected by the value &tgr;. Regarding the corrected signal s″ thereof, a frequency error and an initial phase are obtained such that &egr; is minimized ( ). The signal s″ is corrected by those frequency error and initial phase to generate a signal s′″. An amplitude is measured using the signal s′″ and the reference signal and further, a measurement item is calculated ( ).