Broadband wireless channel comprises many propagation paths having different delay times. This results in a severe frequency-selective fading channel. Frequency-domain equalization reception based on the minimum mean square error criterion (called receive MMSE-FDE in this paper) can exploit the channel frequency-selectivity to improve the bit error rate (BER) performance of broadband single-carrier (SC) signal transmissions in a severe frequency-selective fading channel. If the channel state information (CSI) is available at the transmitter side only, transmit MMSE-FDE can be used instead of receive MMSE-FDE. In this paper, we review classical transmit and receive MMSE-FDEs. Then, assuming the perfect knowledge of CSI at both the transmitter and the receiver, we introduce a joint transmit/receive MMSE-FDE that can further improve the BER performance. A set of transmit/receive weights are presented for the joint MMSE-FDE and evaluate the achievable BER performance.