Frequency-Domain Oversampling for Zero Padded Orthogonal Signal-Division Multiplexing

Orthogonal signal-division multiplexing (OSDM) is an attractive alternative to conventional orthogonal frequency-division multiplexing (OFDM) since it can reduce the peak-to-average power ratio and provide more flexibility. However, the overlap-add operation in the traditional zero padded (ZP) OSDM system incurs information loss. To cope with this issue, we investigate the use of frequency-domain oversampling for ZP-OSDM in this letter. However, this comes at the price of a cubic direct equalization complexity. To ease this computational burden, a low-complexity equalization algorithm is developed, which can achieve linear complexity in the transformed domain. Numerical results show that the proposed frequency-domain oversampled ZP-OSDM not only outperforms traditional ZP-OSDM and frequency-domain oversampled ZP-OFDM, but also exhibits robustness against residual carrier frequency offset.