Ntt Docomo, Inc.

Etsuhiro Okamoto

Yukihiko Okumura

Tetsuro Kitayama

Hidetoshi Ebara

Mitsuo Iwanaga

A communication method for continuously receiving multiple pieces of data from a radio base station via a radio link. The method includes determining whether or not any one of the multiple pieces of data is lost; and making an instruction to the radio base station to increase the transmission power of the radio base station when it is determined that any one of the multiple pieces of data is lost, the instruction being made before a retransmission timing when the transmitter retransmits the lost data piece.

Communication device, radio communication terminal, radio base station and communication method

Even when transmitted waves of multiple systems become approximately out of phase while diversity transmission is performed in a W-CDMA wireless system, synchronization establishment determination is more adequately performed. In a W-CDMA wireless system, even if it is determined in a normal synchronization establishment determination that synchronization cannot be established, when a phase difference in a common channel of a 0-system and a 1-system is within a certain range and a reception quality of the common channel (or a dedicated channel) has reached a certain level, it is determined that the synchronization can be established. Therefore, even when the transmitted waves of the multiple systems become approximately out of phase while the diversity transmission is performed in the W-CDMA wireless system, the synchronization establishment determination can be more adequately performed depending on whether or not communication is possible in an actual state.

Mobile communication system, user equipment in mobile communication system, control program thereof, and synchronization establishment determination method in mobile communication system

In a transmission power control method, a receiver receives user data transmitted intermittently from a transmitter to a receiver and control data transmitted continuously from the transmitter to a plurality of receivers including the receiver via a DPDCH and a CPICH, respectively; and generates, when the receiver is receiving the user data from the transmitter via the DPDCH, a command for controlling transmission power of the transmitter of a DPDCH in a manner that an SIR of a received signal of the DPDCH by the receiver becomes equal to a target SIR, and generates, when the receiver is not receiving the user data from the transmitter via the DPDCH, a command for controlling the transmission power of the transmitter of the DPDCH by updating the target SIR by using received quality of the CPICH.

Transmission power control method and apparatus

In a W-CDMA wireless system, when communication is performed by using a StandAlone-DCCH, adequate transmission power control is performed depending on change in a communication status. In a W-CDMA wireless system, a reception quality of a common channel is measured, and if a StandAlone-DCCH state has occurred, transmission power control corresponding to the common channel is performed in which a target SIR is determined depending on the reception quality of the common channel. Therefore, even in the StandAlone-DCCH state in which Blind transport format detection is used, it is possible to set the target SIR in accordance with a reception status of a user equipment, enabling the adequate transmission power control depending on the change in the communication status.

Mobile communication system, user equipment in mobile communication system, control program thereof, and transmission power control method in mobile communication system

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Osaka, Japan

Etsuhiro Okamoto