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:
Aug. 15, 2000
Filed:
Dec. 08, 1997
Juichi Nakada, Kumagaya, JP;
Advantest Corporation, Tokyo, JP;
Abstract
The present invention offers a method and apparatus for measuring the waveform quality of a CDMA signal with increased accuracy. A baseband digital measuring signal Z(k) from a quadrature transform/complementary filter 22 is applied to a demodulating part 25, wherein it is demodulated by a PN code of a pilot signal to detect a bit train and an amplitude a'.sub.i. An ideal signal R.sub.i is generated from the bit train, the amplitude a'.sub.i and the PN code. At the same time, auxiliary data A, B, C, H and I, which are used to solve approximate simultaneous equations for computing parameters that minimize the square of the difference between the ideal signal R.sub.i and the measuring signal Z(k), are generated in an ideal signal/auxiliary data generating part 26. The thus obtained auxiliary data and the measuring signal Z(k) are used to solve the simultaneous equations to estimate the parameters in a parameter estimating part 27. The parameters are optimized by repeatedly correcting the measuring signal Z(k), the ideal signal R.sub.i and the auxiliary data A, B, C, H, I based on-the estimated parameters and estimating the parameters based on the corrected data. When the parameters are optimized, the power coefficient .rho..sub.i is computed using the optimized measuring signal Z(k) and the PN code.