GSC-based frequency-domain equalizer for CP-free OFDM systems

A multi-antenna generalized sidelobe canceller (GSC) based equalizer for inter-symbol interference (ISI) suppression is proposed for high-rate single-input multiple-output (SIMO) orthogonal frequency division multiplexing (OFDM) systems without cyclic prefix (CP). The proposed method relies on the block representation of the OFDM transmission and exploits the ISI subspace structure in the associated multi-antenna system model. A computationally efficient partial adaptivity (PA) implementation of the GSC equalizer is also provided for reducing the receiver complexity. Simulation results show that the proposed GSC-based solution yields an equalization performance almost identical to that obtained by the conventional CP-based OFDM system and is highly resistant to the increase of channel delay spread.