Radio relay station apparatus, radio base station apparatus and transmission power control method

A radio relay station apparatus comprising:

• receiving section configured to receive a downlink signal including relay information as to whether or not a mobile terminal apparatus performs relay transmission;
• relay amplification factor control section configured to control a relay amplification factor when performing the relay transmission when the relay information is information indicating that the relay transmission is performed;
• and
• transmitting section configured to transmit an uplink signal amplified at the controlled relay amplification factor, wherein:
• the relay amplification factor control section controls the relay amplification factor so that a power density of a signal from the mobile terminal apparatus received at a radio base station apparatus via the radio relay station apparatus becomes substantially equal to a case where transmission is performed without relay transmission, and
• the relay amplification factor G is calculated by following equation (2):
• G=T(no relay)−T(relay)+(1−α(relay))PLUE-RS −(1−α(no relay))PLUE-BS +PLRS-BS Equation (2)
• where, T(no relay) is a reference target reception SNR when relay transmission is not performed, T(relay) is a reference target reception SNR when relay transmission is performed, α(relay) is an attenuation coefficient of the fractional TPC when relay transmission is performed, α(no relay) is an attenuation coefficient of fractional TPC when relay transmission is not performed, PLUE-BS is path loss between the mobile terminal apparatus and the radio base station apparatus and PLRS-BSis path loss between the radio relay station apparatus and the radio base station apparatus.

A radio base station apparatus comprising:

• relay information generating section configured to determine whether or not a mobile terminal apparatus performs relay transmission;
• relay station control signal generating section configured to determine, a relay amplification factor when performing the relay transmission when the relay transmission is performed;
• and
• transmitting section configured to transmit relay information including information of the relay amplification factor to a radio relay station apparatus, wherein:
• the relay station control signal generating section determines the relay amplification factor so that a power density of a signal from the mobile terminal apparatus received at a radio base station apparatus via the radio relay station apparatus becomes substantially equal to a case where the mobile terminal apparatus exists at a position of the radio relay station apparatus and performs transmission without relay transmission.

A radio base station apparatus comprising:

• relay information generating section configured to determine whether or not a mobile terminal apparatus performs relay transmission;
• relay station control signal generating section configured to determine, a relay amplification factor when performing the relay transmission when relay transmission is performed;
• and
• transmitting section configured to transmit relay information including information of the relay amplification factor to a radio relay station apparatus, wherein:
• the relay station control signal generating section controls the relay amplification factor so that a power density of a signal from the mobile terminal apparatus received at a radio base station apparatus via a radio relay station apparatus becomes substantially equal to a case where transmission is performed without relay transmission, and
• the relay amplification factor G is calculated by following equation (2):
• G=T(no relay)−T(relay)+(1−α(relay)) PLUE-RS+(1α(no relay)PLRS-BS+PLRS-BS Equation (2)
• where, T(no relay) is a reference target reception SNR when relay transmission is not performed, T(relay) is a reference target reception SNR when relay transmission is performed, α(relay) is an attenuation coefficient of the fractional TPC when relay transmission is performed, α(no relay) is an attenuation coefficient of fractional TPC when relay transmission is not performed, PLUE-BS is path loss between the mobile terminal apparatus and the radio relay station apparatus, and PLRS-BS is path loss between the radio relay station apparatus and the radio base station apparatus.

A transmission power control method comprising the steps of:

• receiving a downlink signal including relay information as to whether or not a mobile terminal apparatus performs relay transmission;
• controlling, a relay amplification factor when performing the relay transmission when relay transmission is performed;
• and
• transmitting an uplink signal amplified at the controlled relay amplification factor, wherein:
• the relay amplification factor is controlled so that a power density of a signal from the mobile terminal apparatus received at a radio base station apparatus via a radio relay station apparatus becomes substantially equal to a case where the mobile terminal apparatus exists at the position of the radio relay station apparatus and performs transmission without relay transmission.

A transmission power control method comprising the steps of:

• receiving a downlink signal including relay information as to whether or not a mobile terminal apparatus performs relay transmission;
• controlling, a relay amplification factor when performing the relay transmission when relay transmission is performed;
• and
• transmitting an uplink signal amplified at the controlled relay amplification factor, wherein:
• the relay amplification factor is controlled so that a power density of a signal from the mobile terminal apparatus received at a radio base station apparatus via a radio relay station apparatus becomes substantially equal to a case where transmission is performed without relay transmission, and
• the relay amplification factor G is calculated by following equation (2):
• G=T(no relay)−T(relay)+(1−α(relay))PLUE-RS+(1α(no relay))PL UE-BS +PLRS-BS Equation (2)
• where, T(no relay) is a reference target reception SNR when relay transmission is not performed, T(relay) is a reference target reception SNR when relay transmission is performed, α(relay) is an attenuation coefficient of the fractional TPC when relay transmission is performed, α(no relay) is an attenuation coefficient of fractional TPC when relay transmission is not performed, PLUE-BS is path loss between the mobile terminal apparatus and the radio base station apparatus and PLRS-BS is path loss between the radio relay station apparatus and the radio base station apparatus.