Patent ID: 8155064

Claim:
A communication system, comprising: a base station; and mobile stations; wherein the base station includes a group management unit configured to classify the mobile stations into groups according to signal quality information transmitted from the mobile stations, a storing unit configured to store correspondence information on the correspondence between the groups and subframes constituting at least a part of a radio frame, a scheduling unit configured to schedule packets for the mobile stations according to the correspondence information, and a transmitting unit configured to transmit the correspondence information to the mobile stations, wherein the groups are each associated with MCS numbers indicating combinations of modulation schemes and channel coding rates; each of the mobile stations includes a transmitting unit configured to transmit the signal quality information indicating received signal quality to the base station, and a receiving unit configured to receive the packets transmitted from the base station in one of the subframes that corresponds to one of the groups to which the each of the mobile stations belongs, the group management unit configured to determine whether to change the groups to which the respective mobile stations belong based on the signal quality information transmitted from the mobile stations, the transmitting unit configured to report changes in the groups to the mobile stations, and each of the changes in the groups is limited such that a corresponding MCS number is decreased or increased by only one at a time.