Other

Hitachi, Ltd.

Kddi Corporation

Naoki Tsubaki

Toshinori Suzuki

Joichi Saito

Yuuji Ishida

Yoshio Takeuchi

Naruhito Nakahara

Sumaru Niida

Takao Inoue

Masayasu Suzuki

Arata Nakagoshi

Hideki Shimizu

In an interleaver for use in a turbo decoder, a deinterleaver, or an interleaver for use in a turbo encoder, an offset is set based on previously determined thresholds in accordance with symbol numbers generated by a counter. A symbol numbers inputted immediately before generating an address is corrected with the set offset, and the corrected symbol number is converted to generate an interleave read address.

Turbo decoder, turbo encoder and radio base station with turbo decoder and turbo encoder

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

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

Growing community of inventors

Yokohama, Japan

Naoki Tsubaki