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:
Feb. 16, 1999
Filed:
Sep. 23, 1997
Ke-Chiang Huang, Hsinchu, TW;
Industrial Technology Research Institute, Hsinchu, TW;
Abstract
A digital QPSK demodulator includes a plurality of two-input-two-output (TITO) two-fold decimators where each TITO two-fold decimator operates at a rate equal to its input data rate. The in-phase I signal and the quadrature Q signal are computed in an interleaved sequence of {Q'(n), I'(n), Q'(n+1), I'(n+1), . . . } to generate Q' decimation output and I' decimation output. The TITO two-fold decimators are cascaded in a reverse order to form a programmable down-sampler which decimates the input data by factors of 1, 2, 4, 8 or more. In a first embodiment, the programmable down-sampler is coupled between a complex multiplier and an interpolator. In a second embodiment, the in-phase and quadrature signals are fed through a complex multiplier, an interpolator, then the programmable down-sampler. In the third embodiment, the in-phase and quadrature signals are fed through an interpolator, a complex multiplier, then the programmable down-sampler.