1. A method for determining a channel quality indicator (CQI) in a transmission system, the method comprising: receiving, over the transmission system at a receiver, a codeword; determining, at the receiver, a performance measure that is dependent on the CQI for the codeword; determining, at the receiver, an objective function, wherein the objective function is based on the CQI and the performance measure; and selecting, at the receiver, a value for the CQI by performing an optimization technique on the objective function, wherein the optimization technique is performed on the objective function over a range of candidate CQI values, and the selected value for the CQI is the candidate CQI value that optimizes the objective function.