Ntt Docomo, Inc.

Tokyo Institute of Technology

Hui Shi

Takahiro Asai

Hitoshi Yoshino

Tetsushi Abe

Hiroshi Suzuki

Satoshi Suyama

Kazuhiko Fukawa

Hiromasa Fujii

Takefumi Yamada

Hirosama Fujii

A shared frequency transmitter for use in a network environment where transmitters and receivers of plural radio communication systems in which the same frequency is used exist is disclosed. The shared frequency transmitter includes (a) a communicating unit configured to detect peripheral transmitters existing in a peripheral area, and to exchange information with the detected peripheral transmitters; and (b) a signal generating unit configured to generate a transmit signal by applying an interference cancellation technique based on the information obtained through the exchange of information.

Shared frequency transmitter

To improve the channel capacity of an entire communication system in accordance with transmission quality of the channels of each node. A relay node has: a receiving section that receives a received signal from a source node; a channel estimation section that measures SNR of a backward channel between the source node and the relay node, and SNR of a forward channel between the relay node and a destination node; a relay selecting section that selects, from among a QR-P-ZF method, a QR-P-QR method and a ZF-P-QR method, a relay method of the relay node in accordance with the ratio between the SNRs of the backward and forward channels; a relay signal processing section that multiplies the received signal by a transmission weight matrix corresponding to the selected relay method, and thereby converts the received signal to a relay signal; and a transmitting section that transmits the relay signal to the destination node.

Relay node and relay method

A radio communication apparatus for performing transmission and reception based on radio communication includes: a power suppressor for coupling loop interference signal for attenuating signal power of a received signal to suppress the coupling loop interference signal power of the received signal; and a transceiver having a coupling loop interference signal removal function for analog domain and/or a coupling loop interference signal removal function for digital domain, for removing a coupling loop interference signal contained in a signal output from the power suppressor for coupling loop interference signal.

Radio communication apparatus and radio communication method

A communication node for relaying a signal between a source node and a destination node is disclosed. The communication node includes: a relay signal generation unit configured to generate a transmit signal by reducing, from a receive signal, an interference signal from another communication node and performing a process such that the transmit signal is not received as an interference signal by another communication node.

Communication node, wireless communication system and data relay method

A radio communication apparatus for performing transmission and reception of radio communications simultaneously by using different carrier frequencies for transmission and reception, comprising: a transceiver having a coupling loop interference signal removal function for analog domain and/or a coupling loop interference signal removal function for digital domain, for removing a coupling loop interference signal contained in a signal; and a power suppressor for coupling loop interference signal for attenuating the signal power in order to suppress the coupling loop interference signal power that is contained in the signal.

A communication node that relays signals between a source node and a destination node includes (a) a first unitary matrix calculation unit configured to calculate a first unitary matrix based on a first channel between the source node and the relay node, (b) a second unitary matrix calculation unit configured to calculate a second unitary matrix based on a second channel between the relay node and the destination node, (c) a transformation matrix estimation unit configured to estimate a transformation matrix based on a triangular matrix derived from QR decomposition of the first and/or second channel matrix, (d) a relaying signal generator configured to generates a relaying signal by multiplying a received signal by at least one of the first unitary matrix, the second unitary matrix, and the transformation matrix, and (e) a transmission unit configured to transmit the relaying signal to the destination node.

Communication system and method using a relay node

A communication node relays a transmission signal transmitted from a desired source node to a target destination node among multiple source nodes and multiple destination nodes. The communication node includes a first unitary matrix estimation unit that estimates a first unitary matrix by performing singular value decomposition involving one or more channel matrices between the relay node and the source nodes other than the desired source node; a second unitary matrix estimation unit that estimates a second unitary matrix by performing singular value decomposition involving one or more channel matrices between the relay node and the destination nodes other than the target destination node; and a transmission unit configured to transmit a relaying signal generated by multiplying a received signal by the first and second unitary matrices toward the target destination node.

Growing community of inventors

Yokohama, Japan

Hui Shi