Victor Company of Japan, Limited

Takaaki Saiki

Keiichi Kaneko

Kazunari Matsui

Katsumi Takaoka

Data pieces representative of in-phase components and quadrature components of a digital-modulation-resultant signal are assigned to frequencies for inverse fast Fourier transform. The inverse fast Fourier transform is executed at a predetermined sampling frequency Fs to convert the data pieces into a real-part signal and an imaginary-part signal. Phases of the real-part signal and the imaginary-part signal are shifted. Each of the phase-shifted real-part signal and the phase-shifted imaginary-part signal is divided into a sequence of even-numbered samples and a sequence of odd-numbered samples. A digital quadrature-modulation-resultant signal is generated from further manipulation of the even-numbered and odd-numbered samples.

Method and apparatus for modulation and demodulation related to orthogonal frequency division multiplexing

A first orthogonal-multi-carrier signal is generated through N-point inverse discrete Fourier transform. The first orthogonal-multi-carrier signal has &ldquo;N&rdquo; or less orthogonal multiple carriers, where &ldquo;N&rdquo; denotes a predetermined natural number equal to or greater than 2. Every 1-unit time segment of the first orthogonal-multi-carrier signal is repeated &ldquo;M&rdquo; times to generate every 1-symbol time segment of a second orthogonal-multi-carrier signal. The second orthogonal-multi-carrier signal has a thinned set of &ldquo;N&rdquo; or less orthogonal multiple carriers spaced at M-carrier intervals, where &ldquo;M&rdquo; denotes a predetermined natural number equal to or greater than 2.

Generation and decoding of multi-carrier signal

High-frequency components are extracted from an OFDM signal. A symbol clock signal is generated in response to the extracted high-frequency components. Specifically, a sample clock signal is generated in response to the OFDM signal. A frequency of the sample clock signal is divided to generate the symbol clock signal from the sample clock signal. A timing of the frequency division is controlled in response to the extracted high-frequency components.

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Yokosuka, Japan

Takaaki Saiki