With the increase of physical antenna and subcarrier numbers in MIMO-OFDM systems,the signal precoding complexity overburden and channel side information feedback amount would become enormous and intolerable.Previous works precoded MIMO signals in the same subcarrier group with a fixed grouping size,which reduced system overburden with negligible performance degradation but lost control of channel capacity.To solve this problem,this paper exploited frequency correlation and propose an adaptive subcarrier grouping algorithm,which not only enables to reduce system overburden significantly but also to have a good control of system service quality.