Radio base station, radio communication system and radio communication method

A radio communication method for a radio base station that outputs a plurality of beams of varying tilt angles and forms a plurality of cells in a vertical direction, and a user terminal that establishes wireless connection with the radio base station, the radio communication method comprising the steps in which:

• the radio base station:
• acquires information about communication capacity of each of the plurality of cells;
• selects a predetermined user terminal that can connect with a cell having lower communication capacity with predetermined quality or above, among user terminals that are present in a coverage area of a cell having higher communication capacity among the plurality of cells;
• and
• provides a time period to allocate resources to the cell having lower communication capacity and not allocate resources to the cell having higher communication capacity, and, in the time period, allocate resources to the predetermined user terminal from the cell having lower communication capacity,
• wherein, in the time period, the radio base station changes at least one of a tilt angle and a vertical plane beam width of a beam to form the cell having lower communication capacity so that a coverage area of the cell having lower communication capacity expands in a direction of the coverage area of the cell having higher communication capacity formed outside the time period.

A radio base station that forms a plurality of cells in a vertical direction, the radio base station comprising:

• an antenna section configured to output a plurality of beams of varying tilt angles and form a plurality of cells;
• an information acquiring section configured to acquire information about communication capacity of each of the plurality or cells;
• and
• a control section configured to set the amount of resources to allocate to a cell having lower communication capacity among the plurality of cells lower than for a cell having higher communication capacity,
• wherein the control section makes at least one of a frequency range to allocate resources to the cell having lower communication capacity among the plurality of cells and a time period to allocate resources, narrower than for the cell having higher communication capacity,
• wherein the control provides a time period to allocate resources to the cell having higher communication capacity and not allocate resources to the cell having lower communication capacity, and, in the time period, increases the transmission power of the cell having higher communication capacity,
• wherein, in the time period, the control section changes a tilt angle of the beam forming the cell having higher communication capacity so that a coverage area of the cell having higher communication capacity expands in a direction of the coverage area of the cell having lower communication capacity formed outside the time period.

A radio communication system comprising a radio base station that forms a plurality of cells in a vertical direction and a user terminal that establishes wireless connection with the radio base station, wherein the radio base station comprises:

• an antenna section configured to output a plurality of beams of varying tilt angles and form a plurality of cells;
• an information acquiring section configured to acquire information about communication capacity of each of the plurality of cells;
• and
• a control section configured to set the amount of resources to allocate to a cell having lower communication capacity among the plurality of cells lower than for a cell having higher communication capacity,
• wherein the control section makes at least one of a frequency range to allocate resources to the cell having lower communication capacity among the plurality of cells and a time period to allocate resource, narrower than for the cell having higher communication capacity,
• wherein the control section provides a time period to allocate to the cell having higher communication capacity and not allocate resources to the cell having lower communication capacity, and, in the time period, increases the transmission power of the cell having higher communication capacity,
• wherein, in the time period, the control section changes a tilt angle of the beam forming the cell having higher communication capacity so that a coverage area of the cell having higher communication capacity expands in a direction of the area of the cell having lower communication capacity formed outside the time period.