A method for operating a transmitter, the method comprising: transmitting OFDM symbols (32, 34) to a plurality of mobile stations according to an allocation of non-overlapping channels in a two-dimensional resource space, wherein the resource space has (a) a frequency dimension including a plurality of sub-carriers (20, 22) within an OFDM band and (b) a time dimension including OFDM symbol durations that correspond respectively to the OFDM symbols (32, 34), sub-dividing the plurality of sub-carriers into resource blocks, each resource block comprising a fixed number of contiguous sub-carriers over at least one OFDM symbol duration, wherein each of the mobile stations is allocated one of the channels, wherein the channels include diversity channels and sub-band channels (102, 130, 132, 133), each diversity channel being associated with a plurality of sub-carriers (20, 22) distributed across the OFDM band, and each sub-band channel being associated with a contiguous set of sub-carriers (20, 22) within the OFDM band, wherein each resource block in its entirety is allocated for one of sub-band channel use or diversity channel use; organizing sub-band sub-channels into allowable combinations for the sub-band channels and diversity sub-channels into allowable combinations for the diversity channels, wherein diversity sub-channels are defined from sub-carriers allocated for diversity channel use, and wherein sub-band sub-channels are defined from sub-carriers allocated for sub-band channel use; wherein the transmission of at least some of the OFDM symbols (32, 34) simultaneously uses sub-carriers (20, 22) associated with a sub-band channel and sub-carriers (20, 22) associated with a diversity channel. transmitting OFDM symbols (32, 34) to a plurality of mobile stations according to an allocation of non-overlapping channels in a two-dimensional resource space, wherein the resource space has (a) a frequency dimension including a plurality of sub-carriers (20, 22) within an OFDM band and (b) a time dimension including OFDM symbol durations that correspond respectively to the OFDM symbols (32, 34), sub-dividing the plurality of sub-carriers into resource blocks, each resource block comprising a fixed number of contiguous sub-carriers over at least one OFDM symbol duration, wherein each of the mobile stations is allocated one of the channels, wherein the channels include diversity channels and sub-band channels (102, 130, 132, 133), each diversity channel being associated with a plurality of sub-carriers (20, 22) distributed across the OFDM band, and each sub-band channel being associated with a contiguous set of sub-carriers (20, 22) within the OFDM band, wherein each resource block in its entirety is allocated for one of sub-band channel use or diversity channel use; organizing sub-band sub-channels into allowable combinations for the sub-band channels and diversity sub-channels into allowable combinations for the diversity channels, wherein diversity sub-channels are defined from sub-carriers allocated for diversity channel use, and wherein sub-band sub-channels are defined from sub-carriers allocated for sub-band channel use; wherein the transmission of at least some of the OFDM symbols (32, 34) simultaneously uses sub-carriers (20, 22) associated with a sub-band channel and sub-carriers (20, 22) associated with a diversity channel.