Lattice-reduction aided soft-output detector for spectrally efficient FDM system

In this paper, we propose the lattice-reduction (LR) aided soft-output detector in conjunction with channel decoder for spectrally efficient frequency division multiplexing (SE-FDM) system. The SE-FDM system can increase spectral efficiency by overlapping the subcarrier closer than the orthogonality condition, but result in inter-carrier-interference (ICI) at receiver. Thus, we utilize the LR-aided detector to achieve near optimum performance by reducing the basis of ICI term in equalization process. In addition, we also study the soft-output LR-aided detector with convolutional coding. Through the Monte Carlo simulation, the LR-aided detector shows good trade-off between complexity and performance for both uncoded and coded SE-FDM system.