Nara Institute of Science and Technology

Sky Perfect Jsat Corporation

Kiyotake Ando

Takao Hara

Mayumi Osato

Anwar Khoirul

A code synchronization circuit for a delay time measurement device used in a low C/N environment is provided. The code synchronization circuit is capable of high precision timing phase measurement and stable operation against variations in the reception level. For these purposes, the code synchronization circuit includes: a numeric control frequency variable oscillation section () for generating a clock signal with a variable frequency; a 2-divider () for dividing the clock signal by 2 to generate a component code signal (X); a T/2 delay device () for outputting a delayed component code signal (x) lagging in phase behind the component code signal (X) by half a bit; and a second correlator (B) for outputting a second correlation value indicating similarity between the delayed component code signal (x) and the carrier signal, where the numeric control frequency variable oscillation section () controls the frequency of the clock signal according to the second correlation value so that the carrier signal and the clock signal are in sync.

Code synchronization circuit, delay time measurement device, control method, control program, and computer-readable storage medium

The transmitter of one embodiment of the present invention includes: a S/P section for converting original serial data to parallel data which will correspond to a plurality of subcarriers; and a second IFFT section for converting the parallel data from the frequency domain to the time domain. The transmitter includes, between the S/P section and the second IFFT section, a first IFFT section for modulating the plurality of subcarriers using elements of a matrix derived from an expression for Inverse Discrete Fourier Transform involving time domain signal levels and frequency domain signal levels. The configuration enables CI and PO-CI to be implemented on transmitters and receivers with a simple configuration.

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Minato-ku, Japan

Kiyotake Ando