Sharp Kabushiki Kaisha Corporation

Seiichi Sanpei

Naoki Okamoto

Norihiko Morinaga

Yoshiteru Matsushita

Improvement of transmission efficiency is sought by stopping transmission of unnecessary MLI data. A transmitting circuitin a base station apparatushas an MLI modulation partcomposed of an MLI generating circuit, a symbol modulation circuit, and an IFFT circuit, a user data modulation partcomposed of an encoder circuit, a symbol modulation circuit, a transmission power control circuit, and an IFFT circuit, and a transmission operation control circuit. The transmission operation control circuitcontrols operation timing of the MLI modulation part, the user datamodulationpart, and a multiplexerbased on a signal to notify that ACK input from a receiving circuithas been received so that slots containing no MLI data are generated.

Wireless communication system

A TDMA radio communication system using a multiple subcarrier modulation method and comprising at least a first and a second radio station. The first radio station carries out communications by selectively modulating a subcarrier with which a desired transmission rate can be obtained in the second radio station, thereby providing a radio communication system that does not require the monitoring of each time slot by a terminal.

Radio communication system

A TDMA radio communication system uses a multiple sub-carrier modulation method. The TDMA radio communication system comprises at least a first and a second radio station. The second radio station selects only those sub-carriers capable of providing a transmission rate not less than a predetermined value in the first radio station, on the basis of the reception conditions of each sub-carrier of said first radio station. The second radio station then modulates the selected sub-carriers using a modulation level or a coding rate in accordance with the reception conditions of the sub-carriers so as to perform communication, thereby obtaining a desired transmission rate while controlling interface to other stations.

Growing community of inventors

Osaka, Japan

Seiichi Sanpei