Communication system, base station, mobile station, and reception quality determination method

A base station comprising:

• a plurality of antennas that are separate from each other;
• a memory;
• a processor that is coupled to the memory and that executes a process, the process comprising mapping a plurality of reference signals separable from each other onto the plurality of antennas and selecting a candidate cell for cooperative communication in accordance with reception quality notified from a mobile station;
• and
• a radio frequency circuit that transmits the mapped reference signals through the antennas and receives notification about the reception quality in consideration of gain of beam-forming transmission performed with the plurality of antennas from the mobile station, the reception quality being determined by the mobile station with the reference signals,
• wherein
• the process comprises instructing the mobile station of a method for determining the reception quality in accordance with a type of the beam-forming transmission.

A mobile station that communicates with a base station including a plurality of antennas that are separate from each other, the mobile station comprising:

• a radio frequency circuit that receives a plurality of reference signals, the reference signals being mapped onto the plurality of antennas and being separable from each other;
• a memory;
• and
• a processor that is coupled to the memory and that executes a process, the process comprising determining reception quality in consideration of gain of beam-forming transmission performed by the base station with the plurality of antennas, using the received reference signals, and notifying the base station of the determined reception quality, wherein
• the radio frequency circuit receives an instruction of a method for determining the reception quality in accordance with a type of the beam-forming transmission.

A reception quality determination method comprising:

• receiving a plurality of reference signals, the reference signals being mapped onto a plurality of antennas and being separable from each other, the antennas separating from each other and being included in a base station;
• and
• determining reception quality in consideration of gain of beam-forming transmission performed by the base station with the plurality of antennas, using the received reference signals, wherein
• the receiving includes receiving an instruction of a method for determining the reception quality in accordance with a type of the beam-forming transmission performed by the base station with the plurality of antennas.