Communication device and communication method

A communication device comprising:

• a first antenna and a second antenna which receive wireless signals sent by a plurality of communication terminals, the wireless signals containing communication data;
• a selection unit configured to select the first antenna in a first term, and the second antenna in a second term different from the first term;
• a reception determination unit configured to determine whether or not the communication data contained in the wireless signals received by a selected one of the first antenna and the second antenna selected by the selection unit is successfully obtained;
• and
• a storage unit which stores association between each of the communication terminals and one of the first antenna and the second antenna,
• wherein the selection unit is configured to set a length of the first term and a length of the second term by referring to the association, the length of the first term and the length of the second term being set to make a ratio of the length of the second term to the length of the first term equal to a ratio of the number of times the communication data sent by the communication terminal associated with the second antenna is determined to be successfully obtained, to the number of times the communication data sent by the communication terminal associated with the first antenna is determined to be successfully obtained.