This paper is focused on low-complexity joint-detection (JD) algorithms, where the computational complexity is reduced using banks of discrete Fourier transformations. Mainly, we have developed a fast hybrid zero-forcing block decision-feedback equalizer (H-ZF-BDFE) combining the Fourier-based JD scheme (IEEE J. Sel. Areas Commun., vol. 19, p. 1461, 2001) with the fast decision-feedback structure (F-ZF-BDFE) IEEE J. Sel. Areas Commun., vol. 19, p. 245, 2001. In a Rayleigh frequency-selective fading channel, the new structure yields an improvement in E/sub b//N/sub 0/ of almost 2 dB against the fast block linear equalizer (BLE) (IEEE J. Sel. Areas Commun., vol. 19, p. 1461, 2001) at a bit error rate (BER)=10/sup -3/. Moreover, it has the same performance as the F-ZF-BDFE, but the computational complexity for the signal processing is reduced by almost 50%.