Radio base station, radio terminal, and communication control method

A communication control method in a radio base station of an adaptive array scheme applying an antenna weight to a plurality of antennas, comprising:

• a control step of setting a reference signal transmission frequency band available in a transmission of a reference signal from a serving radio terminal, the reference signal being referenced in the calculation of the antenna weight, and of assigning a radio resource of the set reference signal transmission frequency band to the serving radio terminal, wherein
• the control step includes a step of setting an antenna weight to control beam directionality for a radio resource having a frequency band of a reference signal received most recently, from among the radio resources of the reference signal transmission frequency band, based on the reference signal received most recently, and
• the control step includes a step of setting the antenna weight so that a desired wave direction of a downlink beam having a frequency band of the reference signal, from the reference signal transmission frequency band, is directed towards the serving radio terminal.

A radio terminal that performs radio communication with a radio base station of an adaptive array scheme applying an antenna weight to a plurality of antennas so as to control beam directionality, comprising:

• a reception unit that receives information on a first reference signal transmission frequency band available in a transmission of a reference signal referenced in the calculation of the antenna weight, and
• a control unit that sets a second reference signal transmission frequency band included in the first reference signal transmission frequency band, based on a communication quality with the radio base station, and transmits the reference signal using the second reference signal transmission frequency band, wherein
• the reference signal is used for the radio base station setting the antenna weight so that a desired wave direction of a transmitted downlink beam is directed towards the radio terminal.

A communication control method for a radio terminal and a radio base station of an adaptive array scheme applying an antenna weight to a plurality of antennas so as to control beam directionality, to perform radio communication, wherein

• the radio terminal receives information on a first reference signal transmission frequency band available in a transmission of a reference signal referenced in the calculation of the antenna weight,
• the radio terminal sets a second reference signal transmission frequency band included in the first reference signal transmission frequency band, based on a communication quality with the radio base station, and then transmits the reference signal using the second reference signal transmission frequency band, and
• the radio base station sets an antenna weight for a radio resource having a second reference signal frequency band of a reference signal received most recently, from among the radio resources of the first reference signal transmission frequency band, based on the reference signal received most recently, so that a desired wave direction of a downlink beam having the second reference signal frequency band is directed towards the radio terminal.