—In this paper, frequency-domain interleaving on a frame-by-frame basis for orthogonal frequency division multiplexing combined with time division multiplexing (OFDM/TDM) using minimum mean square error frequency-domain equalization (MMSE-FDE) is presented. The OFDM/TDM frame signal (i.e., several concatenated OFDM signals) frequency components are interleaved to enhance channel frequency-selectivity and then, MMSE-FDE is applied at the receiver to obtain frequency diversity gain. The bit error rate (BER) performance of OFDM/TDM with and without channel coding is evaluated by computer simulation. It was shown, that frequency-domain interleaving on the frame-by-frame basis for OFDM/TDM using MMSEFDE achieves a better BER performance in comparison with conventional OFDM due to enhanced frequency diversity gain.