Keio University

Kyowa Electronic Instruments Co., Ltd

Denso Wave Corporation

School Judicial Person Ikutokugakuen

Jin Mitsugi

Kiyoshi Egawa

Haruhisa Ichikawa

Yuusuke Kawakita

Yuki Igarashi

Haruki Sakabe

A passive wireless tag to identify a given command which has been received, even while responding to a wireless tag communication device. In this wireless tag, radio waves serving as a predetermined command are received from a wireless tag communication device via an antenna and an RF switch. Signal components are detected from the received radio waves by the detection circuit. The detected signal components are sampled by the sampling circuit in accordance with the timing when the RF switch is controlled to its ON state by a predetermined control signal. The time interval of the ON state is set to be sufficiently shorter than a transfer cycle of the received radio waves. The control circuit thus identifies the foregoing predetermined command according to the sampling results obtained from the sampling circuit.

Wireless tags and wireless tag system

A radio communication apparatus is described that includes a reception antenna, a converter, a calculator, and a separator. The reception antenna receives a mixed signal including two or more backscatter signals respectively transmitted from two or more tag devices and the converter converts the mixed signal into complex data on a complex plane. The calculator calculates phase angles of carrier waves of the two or more backscatter signals to approximate the phase angles into a complex data sequence of a predetermined length, and generates a projector matrix formed of a combination of the phase angles of carrier waves of the two or more backscatter signals. The separator separates the two or more backscatter signals from the mixed signal based on an inverse matrix of the projector matrix and the complex data sequence.

Radio communication apparatus, radio communication system and radio communication method

Provided is a wireless communication system which enables wireless communication in which crosstalk due to multiple access is canceled while using a large number of inexpensive wireless terminals. In order to generate an interference component, an analysis data sequence is generated by applying a Hilbert transform, by a Hilbert transform, to a subcarrier data sequence obtained by extracting a target subcarrier wave component from a finite length data sequence, while a carrier phase difference &#x3a8; is estimated by using the regression analysis by a carrier wave phase estimation unit. After rotation calculation configured to return the analysis data sequence by the carrier phase difference &#x3a8; is performed, conversion into an angle is performed. Further, a multiplication by a desired odd number of multiplication is performed, and then an inverse Hilbert transform is applied.

Wireless communication system

Growing community of inventors

Fujisawa, Japan

Jin Mitsugi