Ntt Docomo, Inc.

Tohoku University

Tatsuo Furuno

Tamami Maruyama

Tomoyuki Ohya

Yasuhiro Oda

Jiyun Shen

Takahiro Asai

Shinji Uebayashi

Hitoshi Yoshino

Anass Benjebbour

Kunio Sawaya

Ngoc Hao Tran

Tomoyuki Ooya

Qiang Chen

Qiaowei Yuan

Hirohito Suda

Tetsu Tanaka

Jianfeng Li

Shiwei Qu

Long Li

Tomoyuki Oya

There is provided a communication system capable of achieving a high usage efficiency of frequencies without the need for cooperation of multiplexed users. A communication system communicates over frequency channels set by dividing a frequency bandwidth assigned to the system allows interference between channels by overlapping the adjacent frequency channels with each other in the frequency domain, or a transmitting and receiving device, which transmits and receives a signal by allowing the interference between symbols at a waveform level for each channel to decrease the occupied bandwidth, is provided with ICI removal and ISI compensation filterserving as either an ICI removal filter for removing the interference between channels or an ISI compensation filter for compensating the interference between symbols.

Communication system, transmitting device, receiving device, and communication method

A propagation path estimation method using an imaging method according to the invention includes a step of, in a case where a reflectarray which causes reflection and scattering in a different direction (&#x3b8;&#x2212;&#x3b7;)&#xb0; from a specular reflection direction &#x3b8;&#xb0; exists on a propagation path from a transmission point to a reception point RX of the radio wave, calculating a virtual reception point VRX by rotating the reception point RX about a rotation center point O, and estimating the propagation path by using the virtual reception point VRX.

Propagation path estimation method and program and apparatus using the same

A propagation path estimation method using an imaging method according to the invention includes a step of, in a case where a reflect array(structure) which causes reflection and scattering in a predetermined direction (&#x3b8;-&#x3b7;)&#xb0; different from a specular reflection direction &#x3b8;&#xb0; exists on a propagation path, rotating the reflect arrayby &#x3b7;/2&#xb0; about a rotation center O to set a virtual rotated reflect array(virtual structure), and estimating the propagation path by using the virtual rotated reflect array

An apparatus having multiple mushroom structures is disclosed. Each of the multiple mushroom structures includes: a ground plate; a patch provided parallel to the ground plate with a separation of a distance to the ground plate, wherein a distance between a ground plate and a patch in a certain mushroom structure is different from a distance between a ground plate and a patch in a different mushroom structure.

Apparatus having mushroom structures

An apparatus having multiple mushroom structures is disclosed. Each of the multiple mushroom structures including: a ground plate; a first patch provided parallel to the ground plate with a separation of a distance to the ground plate; and a second patch provided parallel to the ground plate with a separation of another distance to the ground plate, which another distance being different from the distance from the first patch to the ground plate, wherein the second patch is a passive element which is capacitatively coupled with at least the first patch.

A reflectarray, including: a substrate; and a plurality of patches formed on each of areas into which a principal surface of the substrate is divided, wherein the plurality of patches are formed by including a gap.

Reflectarray

An apparatus having multiple mushroom structures is disclosed. Each of the multiple mushroom structures includes: a ground plate; a first patch provided parallel to the ground plate with a separation of a distance to the ground plate; and a second patch provided parallel to the ground plate with a separation of another distance to the ground plate, which another distance being different from the distance from the first patch to the ground plate, wherein the second patch is a passive element which is capacitatively coupled with at least the first patch.

A relay apparatus is disclosed for relaying a signal from a transmitter to a receiver in a MIMO (Multiple Input Multiple Output) based communication system, comprising: a power difference determination unit configured to determine a difference of reception levels between a direct wave and a relayed wave based on positional relationship among the transmitter, the relay apparatus and the receiver, the direct wave traveling from the transmitter to the receiver without the relay apparatus, the relayed wave traveling from the transmitter to the receiver via the relay apparatus; a gain determination unit configured to determine an amplification gain of the relay apparatus to make the difference smaller; and a transmitting unit configured to amplify the signal from the transmitter at the determined amplification gain and transmit the amplified signal to the receiver.

Relay apparatus and relay method

A radio communication system according to the present invention includes a scatterer configured to reflect, refract, or transmit a radio wave radiated primarily from a transmission side apparatus to radiate the radio wave secondarily to a desired area and a metamaterial is used for the scatterer.

Radio communication system

A communication system capable of achieving a high usage efficiency of frequencies without the need for cooperation of multiplexed users is disclosed. The communication system communicates over frequency channels set by dividing a frequency bandwidth assigned to the system and allows interference between channels by overlapping the adjacent frequency channels with each other in the frequency domain. A transmitting and receiving device, which transmits and receives a signal by allowing the interference between symbols at a waveform level for each channel to decrease the occupied bandwidth, is provided. The receiving device is provided with an Inter-Channel Interference (ICI) removal and Inter-Symbol Interference (ISI) compensation filter serving as either an ICI removal filter for removing the interference between channels or an ISI compensation filter for compensating the interference between symbols.

Communication system, transmission device, reception device, and communication method

A reflect array () according to the present invention includes a plurality of array elements () forming an array configured to control a direction of a reflected wave (scattered wave) by controlling a phase of the reflected wave; and a ground plane (). The ground plane () has a structure with a frequency selective function.

Reflect array

The present invention relates to a radio communication system configured to secondarily-radiate, to a desired area by reflection, primarily-radiated radio waves from a transmitter apparatus, by using a reflector plate for controlling phases of reflected waves, wherein a reflecting property of the reflector plate is set so that the reflector plate reflects the primarily-radiated radio waves as plane waves of equal phase directed to a direction different from a reflection angle in the case of specular reflection.

Radio communication system, periodic structure reflector plate, and tapered mushroom structure

A repeating station, a communication apparatus, and an antenna directivity control method are disclosed. The repeating station includes

Growing community of inventors

Yokosuka, Japan

Tatsuo Furuno