Lattice-reduction aided linear equalizer design for linear complex-field coded OFDM systems

Orthogonal frequency division multiplexing (OFDM) is an effective method to deal with frequency-selective channels since it has low complexity equalization and decoding. To eliminate the effects of the channel nulls and enable multipath diversity, linear complex-field coded (LCFC-) OFDM is introduced and the maximum likelihood decoder is used to collect the diversity. But, the low complexity provided by OFDM is sacrificed. Recently it has been discovered that the performance of linear equalizers may be improved by using lattice-reduction (LR) techniques, in this paper, we analyze the performance of conventional linear equalizers for LCFC-OFDM systems. Then we develop LR aided linear equalizers for LCFC-OFDM systems and prove that complex LR aided linear equalizers collect the same diversity order as that offered by maximum likelihood detectors, but with much lower complexity. Simulation results corroborate the theoretical findings