Adaptive self-orthogonalizing per-tone decision feedback equalizer for single carrier modulations

Frequency-domain decision-feedback equalization (FD-DFE) for single carrier modulation avoids interblock interferences (IBIs) by using guard intervals located in between two data blocks. If the period of a guard interval is shorter than that of the channel impulse response, the IBIs cannot be removed by the FD-DFE, which significantly deteriorates its performance. To handle this IBI problem, this letter introduces the adaptive self-orthogonalizing per-tone FD-DFE without channel estimation, where time dispersiveness, one weakness of the per-tone equalization, is compensated by the self-orthogonalization coming from the lattice structure of the Levinson-Durbin algorithm, which dramatically reduces bit-error rates of the proposed FD-DFE, comparing with the existing FD-DFE.