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. 09, 2011
Filed:
Dec. 29, 2010
Kazuyuki Hori, Tokyo, JP;
Shouhei Murakami, Yokohama, JP;
Yuji Ishida, Fujisawa, JP;
Tomoya Uchiike, Fujisawa, JP;
Yoshiaki Hasegawa, Kawasaki, JP;
Kazuyuki Hori, Tokyo, JP;
Shouhei Murakami, Yokohama, JP;
Yuji Ishida, Fujisawa, JP;
Tomoya Uchiike, Fujisawa, JP;
Yoshiaki Hasegawa, Kawasaki, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
There is a need for effectively compensating distortion when a predistortion transmitter is subject to not only a memory effect due to nonlinearity of an amplifier, but also a modulator's DC offset, IQ unbalance, or local quadrature error. A predistortor to be used is a polynomial predistortor including a polynomial basis generation portion and an inner product calculation portion. The polynomial basis generation portion delays a real part and an imaginary part of a complex input signal Sx=Ix+jQx for up to M samples to generate 2(M+1) signals, duplicately combines these signals to generate monomials having maximum degree N, and outputs, as a basis vector, all or part of the monomials depending or needs. The inner product calculation portion performs an inner product calculation using a coefficient vector, i.e., a set of complex numbers sized equally to the basis vector to find a polynomial value and outputs the value as a complex signal.