Inthispaper,ablockwiseadaptivesubcarrierallocationalgorithmformultiuserOrthogonalFrequencypisionMultiplexing(OFDM)systemisintroduced.Assumingtheknowledgeofchannelinformationforallusers,thealgorithmminimizesthetotaltransmitpowerwhilesatisfyingthetotalpowerandusers'rateconstraints.TheresultofsimulationshowsthattheproposedalgorithmreducestheaveragebitSignal-to-NoiseRatio(SNR)byapproximately4dBcomparedwithOFDM-FrequencypisionMultipleAccess(OFDM-FDMA),andsupportsmoreusersinamultiuserRayleighfadingchannel.Asassigningsubcarriersinblock,thecomputationalcomplexityofthealgorithmismuchlowerthanthatofthederivationof"water-filling"algorithm.
