Subspace based blind detector for multi-carrier CDMA with virtual carriers over dispersive channels

Blind MMSE detection for multi-carrier CDMA (MC-CDMA) systems in the presence of intersymbol interference (ISI) channels is addressed. By exploiting the presence of virtual carriers, a blind detector architecture (subspace based) channel estimator followed by a linear MMSE equalizer-is proposed that achieves high spectral efficiency due to elimination of cyclic prefix while not requiring any training for start-up. Both full and reduced dimension subspace detection is investigated, to highlight possible performance-complexity trade-offs suitable for uplink and downlink applications, respectively.