Nippon Telegraph and Telephone Corporation

Samsung Electronics Co., Ltd.

Kentaro Nishimori

Yasushi Takatori

Keizo Cho

Toshikazu Hori

Tomoki Murakami

Masato Mizoguchi

Riichi Kudo

Takatoshi Sugiyama

Takeo Ichikawa

Jun Mashino

Takefumi Hiraguri

Yusuke Asai

Kengo Nagata

Tsutomu Mitsui

A multi-antenna apparatus for controlling transmission and reception of signals based on channel estimation includes: a signal transmitter configured to transmit a first signal using a multi-antenna; a signal receiver configured to receive a second signal using the multi-antenna based on the transmitted first signal; a signal transferrer configured to receive a third signal received from the signal transmitter and provide the third signal to the signal receiver; and a controller configured to estimate a channel state of the multi-antenna based on the second signal and the third signal obtained from the signal receiver, and control transmission and reception of signals through the multi-antenna according to the estimated channel state.

Method for estimating channel state and controlling transmission/reception signal by multiple antenna device, and multiple antenna device using same

This radio communication method is used to perform spatial multiplexing communication between cells in the overlap cell environment. In the MU-MIMO overlap cell environment, when a null is formed between a radio base station and a radio terminal station belonging to different cells, a first set of a 'call signal' and a 'response signal' is used to perform mutual detection with the radio base station and the radio terminal station belonging to different cells, and then a null is formed so as not to cause interference of radio waves between the radio base station and the radio terminal station belonging to different cells. At this time, the addresses of the radio base station and the radio terminal station are used to discriminate whether the radio base station and the radio terminal station belong to the same cell or different cells.

Radio communication method, radio communication system, radio base station, and radio terminal station

A directivity control system includes a first reception station device which receives an interference signal and a desired signal; a cooperative station device disposed at a different place from the first reception station device, which receives a signal using an antenna; and a control device which controls the directivity of an antenna of the first reception station device, wherein the control device regards a combination of the antenna of the first reception station device and the antenna of the cooperative station device as one array antenna, and calculates a sum, using a weight, of a received signal received using the antenna of the first reception station device and a received signal received using the antenna of the cooperative station device to compose a directivity pattern having a null in an arrival direction of the interference signal in the array antenna.

Directivity control system, control device, cooperative station device, reception station device, and method of controlling directivity

An interference cancelling station ICS includes a transmission weight factor calculating unit calculating a transmission weight factor wand an interference cancelling data signal transmitting unit generating an interference cancelling data signal by multiplying, by the transmission weight factor w, a data signal transmitted by a base station BSb of the wireless communication system B and transmitting the interference cancelling data signal in synchronization with timing with which the base station BSb of a wireless communication system B transmits the data signal, and a mobile station MSa of a wireless communication system A receives a data signal transmitted by a base station BSa of the wireless communication system A, the data signal having cancelled interference from the base station BSb of the wireless communication system B.

Wireless communication system, interference cancelling station, and interference cancelling method

An adaptive antenna control method is used for a radio communication system built by a plurality of radio base stations and a plurality of terminal stations capable of communicating with the radio base stations. Each radio base station includes an adaptive antenna having a plurality of antenna elements, a distributor for generating signals to be input to the plurality of antenna elements by branching a signal of one system to be transmitted, and weighting circuits for respectively weighting transmission signals to the plurality of antenna elements. For reception by each terminal station, an interference wave power given by the transmission signal from each of the plurality of radio base stations is estimated. A weight in the adaptive antenna of each radio base station is determined to minimize a sum of square errors between reception signals and desired signals for all the radio base stations which simultaneously use the same communication channel. An adaptive antenna transmission/reception characteristic control method is also disclosed.

Adaptive antenna control method and adaptive antenna transmission/reception characteristic control method

In an array antenna used in a transceiver in a time division communication system such as TDD (Time Division Duplex) system, amplitude and phase of each antenna element are calibrated in a transceiver itself during actual communication without using external information. A first transmitter ( - - ) has means ( - - ) to send a transmit signal to an antenna element ( - - ) as well as to at least one of the receivers ( - - through - -N). Other transmitter ( - - through - -k) except the first transmitter has means ( - -k) which sends a transmit signal to a related antenna element ( - - through - -k) as well as to a first receiver ( - - ) which relates to the first transmitter. Amplitude/phase value obtained in the first receiver ( - - ) and amplitude/phase values obtained in other receivers ( - - through - -k) except the first receiver provide weighted amplitude/phase values of each antenna elements according to desired desired radiation pattern.

Adaptive array antenna system

An adaptive array antenna transceiver apparatus provides: a local signal generator that outputs a signal having a frequency that corresponds to the difference between the reception frequency and the transmitting frequency; a coupler that separates and extracts a part of the signals from the output of the transmitters a switch that selects the signal output from any one of the transmitters a frequency converter that converts the frequency of the signal selected by the switch and a switch that inputs signals output by the frequency converter and selectively outputs them to any one of the plurality of paths. The transceiver further provides a switch that selectively inputs a reception signal from a said antenna elements or a signal from said second switch into each of said receivers; and a calibration control processor that controls the connection state of said switches inputs the amplitude and phase values obtained at the receivers and finds the calibration value of each of the branches of the array antenna.

Adaptive array antenna transceiver apparatus

An adaptive array antenna system for stable directivity control and waveform equalization even under poor multipath environment is provided. An output of antenna elements (A,-A,n) is weight combined (A,), and is output through automatic frequency control (A,) and fractionally spaced adaptive transversal filter (A,) which have real number weights. Weight combination (A,) is initially carried out with weights for an eigen vector beam for the maximum eigen vector of the correlation matrix R,of a receive signal After carrier synchronization and timing synchronization between a receive signal, and an A/D converter and a fractionally spaced transversal filter are established by the automatic frequency control and the fractionally spaced transversal filter, the weight in the weight combiner (A,) is switched to minimum mean square error (MMSE) weight. Sampling rate for A/D conversion under an eigen vector beam forming is higher than twice of that of transmission rate, with asynchronous timing to a receive signal.

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Yokosuka, Japan

Kentaro Nishimori