Channel shortening is often necessary for demodulation of multicarrier signals and complexity reduction of maximum likelihood sequence estimation (MLSE). This paper has two parts: (i) the proposal of complexity-reduction techniques for channel shortening designs with polynomial weighting functions, including the minimum inter-block interference (Min-IBI) and minimum delay spread (MDS) designs, and (ii) the evaluation of several standard channel shorteners, including Min-IBI and MDS, in terms of bit error rate (BER) for an OFDM system. Previous evaluation of channel shortening designs has focused on the wireline case, for which the performance metric (bit rate for fixed BER) is quite different.