Iterative joint MMSE spatial filtering/successive MUI cancellation for frequency-domain filtered SC-FDMA uplink

Frequency-domain filtered single carrier (SC)-FDMA signal has properties of reduced peak-to-average power ratio (PAPR) and increased frequency diversity gain. However, if the carrier-frequency separation is kept the same as in the case of the transmit filter roll-off factor α=0, the adjacent users´ signal spectra overlap and the multi-user interference (MUI) is produced. In our previous work, we proposed an iterative joint single-user minimum mean square error frequency-domain equalization/successive MUI cancellation (called iterative joint MMSE-FDE/SMUIC), which performs iteratively a series of MMSE-FDE, spectrum combining, and SMUIC, for frequency-domain filtered SC-FDMA uplink. However, the residual ISI and MUI limit the BER performance improvement. In this paper, we replace the single-user MMSEFDE by an MMSE spatial filtering (MMSE-SF) and propose an iterative joint multi-user MMSE-SF/SMUIC (called iterative joint MMSE-SF/SMUIC). The achievable bit error rate (BER) and throughput performances are evaluated by computer simulation.