The peak-to-average power ratio (PAPR) of Nyquist filtered broadband single carrier (SC)-FDMA signals can be reduced by increasing the filter roll-off factor α. Furthermore, an additional frequency diversity gain can be obtained by making use of the excess bandwidth introduced by the transmit filtering. However, if the carrier-frequency separation is kept the same as in the case of α=0, the adjacent users' signal spectra overlap with the desired users' spectrum and the multiuser interference (MUI) is produced. In this paper, in order to improve the transmission performance of uplink SC-FDMA using frequency-domain filtering, we propose two type of frequency-domain iterative MUI cancellation scheme which can achieve the frequency diversity gain through MMSE-FDE&spectrum combining. The achievable bit error rate (BER) and throughput performances are evaluated by computer simulation.