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. 05, 2009
Filed:
Jul. 26, 2005
Wayne Edward Richards, La Mesa, CA (US);
Wayne Edward Richards, La Mesa, CA (US);
Cubic Corporation, San Diego, CA (US);
Abstract
Shaped Offset Quadrature Amplitude Modulation (QAM) can be implemented within a communication system. A train or sequence of orthogonal sinc pulses can be generated for each of the in-phase and quadrature signal paths. The sinc pulses in the quadrature signal path can have a predetermined time offset relative to the pulses in the in-phase signal path. An in-phase or quadrature antipodal data signal can be used to modulate the respective sinc pulse train. Each of the in-phase and quadrature pulses can be shaped using a time domain windowing function, such as a Kaiser-Bessel window, to adjust the spectral width and spectral sidelobe level of the signal. The beta parameter of the window can be adjusted to achieve the desired signal response. The timing of the sinc pulses may need to be adjusted following the window function in order to maintain orthogonality of the pulses.