Methods of performing link adaptation in a wireless communication system for simultaneous transmission of codewords include selecting initial modulation and coding scheme (MCS) levels for the codewords, estimating a size ratio of the codewords, determining a number of scheduling blocks (SB) for the codewords with the initial MCS levels, and determining revised MCS levels for the codewords in response to the determined number of SBs. Transport block sizes are computed for the codewords, and it is determined if there is a need to increase the number of scheduling blocks in at least one of the codewords. If there is a need to increase the number of scheduling blocks in a codeword, scheduling blocks are added to the codeword, and the transport block size for the codeword is recomputed. The codewords are then simultaneously transmitted over different multiple input-multiple output (MIMO) communication channels using the same time and frequency resources.