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:
Oct. 07, 2014
Filed:
Apr. 14, 2011
Tadao Nakagawa, Yokosuka, JP;
Yasushi Takatori, Yokosuka, JP;
Riichi Kudo, Yokosuka, JP;
Munehiro Matsui, Yokosuka, JP;
Koichi Ishihara, 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;
Tadao Nakagawa, Yokosuka, JP;
Yasushi Takatori, Yokosuka, JP;
Riichi Kudo, Yokosuka, JP;
Munehiro Matsui, Yokosuka, JP;
Koichi Ishihara, 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;
Nippon Telegraph and Telephone Corporation, Tokyo, JP;
Abstract
When a circuit that calculates a frequency offset using a shape of a frequency spectrum is implemented by hardware, the circuit size can be reduced. A frequency offset estimating method for estimating the difference between a carrier frequency of a reception signal and the frequency of an output signal of a local oscillator includes performing a discrete Fourier transform on a reception signal previously sampled at a predetermined sampling frequency and outputting a frequency spectrum with a plurality of frequency components, calculating an average power of the frequency spectrum, calculating a threshold by adding a predetermined value to the average power or power obtained by multiplying the average power by a constant, performing 1-bit quantization on powers of the frequency components of the frequency spectrum based on the threshold, and calculating a centroid frequency by multiplying frequencies of the frequency components by powers of 1-bit quantized frequency components, calculating the sum of multiplied products, and dividing the sum of the products by the sum of the powers of the 1-bit quantized frequency components of the frequency spectrum.