Hitachi, Ltd.

Other

Kyocera Corporation

Kddi Corporation

Yuuji Ishida

Joichi Saito

Toshinori Suzuki

Naoki Tsubaki

Toshiro Suzuki

Yoshio Takeuchi

Naruhito Nakahara

Sumaru Niida

Satoshi Takahashi

Ken Takei

Kazuyuki Hori

Hideki Shimizu

Hiroshi Usami

Qian He

An electronic apparatus includes a plurality of sound output units. The electronic apparatus includes a detection unit for detecting an object around the electronic apparatus. The electronic apparatus includes a controller for controlling a signal to be output to the sound output unit based on a result of detection by the detection unit.

Electronic apparatus and sound output control method

To satisfy the required SNR values for each system and/or each channel, a peak factor reduction device for reducing peak components included in a transmission signal, generates a cancellation signal to be multiplexed on the transmission signal, and the peak factor reduction device changes an amplitude of the generated cancellation signal according to a signal noise ratio required for the transmission signal and a power level of the transmission signal.

Peak factor reduction device and wireless transmitter

The key device of the present invention is provided with: first light-emitting portions that emit light propagating in a first direction; second light-emitting portions that emit the light R propagating in a second direction; converters H that can convert a propagating direction of light from the first direction to the second direction, or from the second direction to the first direction; first light-receiving portions that receive light propagating in the first direction through the converters; second light-receiving portions that receive light propagating in the second direction through the converters; and a plurality of keys, which are provided correspondingly to the converters, and which determine whether the propagating direction of light is converted in the converters.

Key device and electronic device comprising the same

In a mobile communication system employing code division multiple accesses and having radio logical channels such as control channels and traffic channels, for the purpose of interference cancellation processing which is implemented without a large processing delay even under a call control application, the baseband receiving part of the mobile communication system includes a common control channel demodulatorwhich executes the demodulation processing of a common control channel as to a received baseband reception signal, an interference cancellerwhich executes interference cancellation processing for a received multiplexed signal on the basis of the notification information of the control channels, and a synthesis/error correction processorwhich executes error correction processing, etc. as to user information having undergone the interference cancellation processing and thereafter executes frame formation processing. The common control channel is demodulated by the common control channel demodulatorand is not submitted to interference cancellation processing, thereby to heighten the processing speed of system information. In the interference canceller, cross-correlation interferences are cancelled as to the dedicated control channel and the traffic channel other than the common control channel, thereby to enhance a channel efficiency.

Base station and mobile communication system

A low-cost communication system utilizing a code division multiple access, which controls scale-up of an apparatus due to the provision of an interference suppressing function in a base transceiver station, prevents the reduction of channel utilization efficiency, and enables a high-quality communication. Conventionally, a signal obtained through an interference cancellation stage process has been processed at subsequent cascade-connected stages. The interference cancellation stage process has been carried out by cascade-connecting several circuits performing the same process in a multi-stage interference-canceling device. However, in the present invention, by performing a demodulation process for generating replica signals, feeding back the replica signals to a correlation circuit for another demodulation process, and repeating the same signal process, the interference cancellation stage process is carried out. Such a configuration enables reduction of hardware.

Communication system

In a time-division multiplexing wireless communication system, an antenna module has plural antenna elements. Receiver high-frequency circuit synthesizes signals from the antenna elements according to an antenna directivity having a desired beam pattern. Demodulator selects one of the received signals from wireless terminals according to the synthesized received signals, and determines transmission beam direction information for use in directing the beam in the selected direction. Weighting circuit generates weight coefficients for setting of the beam patterns and transmission beam directions according to the transmission beam direction information, and produces transmission time slots according to a table listing the relations of the transmission beam directions and the time slots for use in the beam radiation in those directions. Down-link fixed beam-forming circuit and modulator control the antenna module using the generated beam pattern, beam direction and transmission time slots to transmit the down-link signal.

Wireless communication method and system using beam direction-variable antenna

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.

Growing community of inventors

Fujisawa, Japan

Yuuji Ishida