Patent ID: 8553525

Claim:
A method of transmitting data, the method comprising: grouping a plurality of mobile stations having a same channel state; generating a frame, the frame comprising a preamble, a map, a submap and a data burst, wherein the submap indicates a resource allocation state of the data burst, and the map indicates an adaptive modulation and coding (AMC) level for the submap; and transmitting data using the frame to the plurality of mobile stations; wherein the AMC level for the submap is determined by a channel state of the plurality of mobile stations, and wherein the submap is a region including control information for the plurality of mobile stations having the same channel state and the control information is encoded using the AMC level indicated by the map, and wherein the map is transmitted through fixed radio resources in the frame, the fixed radio resources comprising an orthogonal frequency division multiplexing (OFDM) symbol contiguous to a first OFDM symbol where the preamble is transmitted, and wherein the map comprises differential AMC level, the differential AMC level is information on change in the AMC level applied to the submap comparing with other submap in a previous frame, and wherein the differential AMC level comprises a value of the amount of change in the AMC level applied to the submap and AMC level up/down information that indicates whether the value is a positive or negative number.