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:
Jul. 15, 2014
Filed:
Jun. 17, 2011
Tadao Nakagawa, Yokosuka, JP;
Munehiro Matsui, Yokosuka, JP;
Koichi Ishihara, Yokosuka, JP;
Riichi Kudo, Yokosuka, JP;
Takayuki Kobayashi, Yokosuka, JP;
Etsushi Yamazaki, Yokosuka, JP;
Akihide Sano, Yokosuka, JP;
Eiji Yoshida, Yokosuka, JP;
Masato Mizoguchi, Yokosuka, JP;
Yutaka Miyamoto, Yokosuka, JP;
Yasushi Takatori, Yokosuka, JP;
Tadao Nakagawa, Yokosuka, JP;
Munehiro Matsui, Yokosuka, JP;
Koichi Ishihara, Yokosuka, JP;
Riichi Kudo, Yokosuka, JP;
Takayuki Kobayashi, Yokosuka, JP;
Etsushi Yamazaki, Yokosuka, JP;
Akihide Sano, Yokosuka, JP;
Eiji Yoshida, Yokosuka, JP;
Masato Mizoguchi, Yokosuka, JP;
Yutaka Miyamoto, Yokosuka, JP;
Yasushi Takatori, Yokosuka, JP;
Nippon Telegraph and Telephone Corporation, Tokyo, JP;
Abstract
Provided is a frequency offset estimation apparatus that appropriately estimates and compensates for a frequency offset of a received signal when estimating the frequency offset which is the difference between a carrier frequency of the received signal and the frequency of an output signal of a local oscillator. The frequency offset estimation apparatus converts the received signal sampled in advance with a predetermined sampling frequency into a frequency spectrum having N frequency components, limits a frequency band of negative frequency components from 1 to N/2 of the frequency spectrum and a frequency band of positive frequency components from N/2+1 to N of the frequency spectrum, calculates the sum of the squares of the positive frequency components of the frequency spectrum that have been subjected to frequency band limitation and the sum of the squares of the negative frequency components of the frequency spectrum that have been subjected to frequency band limitation to calculate power of the positive frequency components and power of the negative frequency components, and cyclically shifts all frequency components of the frequency spectrum in a frequency domain until the absolute value of a power difference between the power of the positive frequency components and the power of the negative frequency components is less than or equal to a predetermined threshold value, and estimates the frequency offset based on a shift amount until the absolute value is less than or equal to the threshold value.