Other

Hitachi, Ltd.

Kddi Corporation

Kdd Corporation

Sumaru Niida

Takashi Inoue

Toshiro Suzuki

Toshinori Suzuki

Nobukazu Doi

Mikio Kuwahara

Yoshio Takeuchi

Yuji Ishida

Naruhito Nakahara

Joichi Saito

Yuuji Ishida

Naoki Tsubaki

Satoshi Masuda

Tatsuto Okamoto

Tsuyoshi Taniguchi

A radio base station apparatus provided with an array antenna having a plurality of antenna elements for calibrating a phase difference among the array antenna elements. The base station has a probe signal adding unit which divides one probe signal and adds the divided probe signals to each receive signals received by the plurality of antenna elements. A probe data extracting unit extracts the probe data from the receive signals added with the probe signal. A phase calibration calculation unit calculates correlating phase calibration values required for calibrating a phase of each receive signal based on the probe data extracted by the probe signal extracting unit. A phase calibration unit calibrates a phase difference among the array antenna elements by calibrating the phase of the each receive signal based on the phase calibration from the phase calibration calculation unit.

Antenna unit and radio base station therewith

Phase and amplitude deviations, which are generated, for example, by cables connecting an array antenna of a CDMA base station and the base station, are calibrated in the baseband. The base station comprises: an antenna apparatus; couplers; an RF unitthat converts a receive signal to a baseband signal, converts a transmit signal to a radio frequency, and performs power control; an A/D converterfor converting a receive signal to a digital signal; a receive beam form unitthat multiplies the receive signal by semi-fixed weight; a despreaderfor this signal input; a time-space demodulatorfor demodulating user data; a despreaderfor probe signal; a space modulatorfor user data; a spreaderfor user signal; a channel combiner; a Tx calibraterfor controlling calibration of a signal; a D/A converter; a unitfor calculation of correlation matrix for generating a probe signal used for controlling an Rx calibration system and a TX calibration system; a spreaderfor probe signal; a power control unit; a D/A converter; an RF unitfor probe signal; an A/D converterfor signal from the couplers; and a despreader

A method of transmitting adaptive modulation signals using space-time block code matrix from a plurality of antennas, the method comprising the steps of: changing adaptively the number of transmission repeat times of the matrix according to a propagation condition, transforming modulation signals at each transmission repeat timing from each antenna by using the matrix, and sending the transformed signals at each transmission repeat timing from each antenna.

Method and apparatus for adaptive modulation using space-time block code matrix

Disclosed is a control apparatus capable of more effectively utilizing radio resources. Mobile stations positioned close to each other are treated as one group, and a direction and width (radiation angle) of a beam radiated from an adaptive array antenna is controlled for each group so that one beam capture one group. To be concrete, a plurality of mobile stations are classified into groups by a classification section , and an area to which each group moves is estimated by a directivity determination section . The adaptive array antenna is controlled by the directivity control section so that one beam can cover an area in which one group is positioned and the area to which this one group moves.

Method of controlling directional antenna and apparatus of the same

A base station apparatus, a mobile radio system, and a transmission power control method that can perform transmission power control having the high interference suppressing effect with a smaller processing delay are provided. The base station apparatus comprises: a measurement part for measuring SIRs of a received signal subjected to interference suppression by an interference suppressing receiving circuit in a former stage in an interference suppressing receiving part of the radio base station apparatus, and of a received signal subjected to interference suppression by an interference suppressing receiving circuit in a later stage; a calculation part for calculating a correction SIR based on the obtained SIRs, and for estimating a transmission power control SIR from a current first stage SIR and a past correction SIR; and a signal generator for generating a transmission power control signal by comparing the transmission power control SIR and a target SIR. Control of transmission power of a mobile station is performed by transmitting this transmission power control signal to the mobile station.

Base station apparatus, mobile communication system, and method of controlling transmission power

In order to prevent decrease of channel efficiency and to effectuate high quality communication while moderating increase of apparatus scale of an interference canceler part and cutting down costs, in a mobile communication and radio base station apparatus according to the present invention, an interference cancel processing part within the base station apparatus is provided with reverse spread processing/respread processing parts for performing reverse spread processing and respread processing on received signals, synthesizing processing parts for synthesizing signals that have been subjected to the respread processing, and subtraction processing parts for subtracting the synthesized signal from received signal, in multiple stages. The interference cancel processing part processes received signals of users &num;1-&num;k. As a demodulation processing part, there is provided n demodulation processing parts that perform demodulation processing for received signals of users &num;1-&num;n, the number of those users being larger than the number of the users that can be processed in the interference cancel processing part. Those demodulation processing parts perform demodulation processing with respect to signals that have been subjected to the interference cancel processing.

Mobile communications system and radio base station apparatus

An apparatus for combining signals includes RAKE receivers 10, 20, noise-power measuring apparatuses 30, 40, and a branch combiner 50. The RAKE receivers 10, 20 are the same in number as the antenna branches, and each RAKE receiver combines received signals by using a weight based on an amplitude of each received signal. Each of the noise-power measuring apparatus 30, 40 measures a sum of an interference power and a background-noise power in an output signal from each RAKE receiver. The branch combiner 50 multiplies the output signal from each RAKE receiver by an inverse of the sum measured by the noise-power measuring apparatus, and then adds up the value obtained by each multiplication.

Growing community of inventors

Irima, Japan

Sumaru Niida