Kyowa Electronic Instruments Co., Ltd

Nippon Telegraph and Telephone Corporation

Keio University

School Judicial Person Ikutokugakuen

Haruhisa Ichikawa

Kiyoshi Egawa

Jin Mitsugi

Yuusuke Kawakita

Satoshi Ono

Yusuke Hisada

Yuki Igarashi

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

An email access control scheme capable of resolving problems of the real email address and enabling a unique identification of the identity of the user while concealing the user identification is disclosed. A personalized access ticket containing a sender's identification and a recipient's identification in correspondence is to be presented by a sender who wishes to send an email to a recipient so as to specify the recipient as an intended destination of the email. Then, accesses between the sender and the recipient by verifying an access right of the sender with respect to the recipient according to the personalized access ticket at a secure communication service. Also, an official identification of each user by which each user is uniquely identifiable by a certification authority, and an anonymous identification of each user containing at least one fragment of the official identification are defined, and each user is identified by the anonymous identification of each user in communications for emails on a communication network.

Email access control scheme for communication network using identification concealment mechanism

Growing community of inventors

Tokyo, Japan

Haruhisa Ichikawa