Enhanced DCT-OFDM System With Index Modulation

Discrete cosine transform (DCT) based orthogonal frequency-division multiplexing (OFDM), which has double the number of subcarriers compared to the classic discrete Fourier transform (DFT) based OFDM (DFT-OFDM) at the same bandwidth, is a promising high spectral efficiency multicarrier technique for future wireless communications. In this paper, an enhanced DCT-OFDM with index modulation (IM) (EDCT-OFDM-IM) is proposed to further exploit the benefits of the DCT-OFDM and IM techniques. To be more specific, a pre-filtering method based DCT-OFDM-IM transmitter is first designed and non-linear maximum likelihood (ML) is developed for the proposed EDCT-OFDM-IM system. Moreover, the average bit error probability of the proposed EDCT-OFDM-IM system is derived, which is confirmed by simulation results. Both simulation and theoretical results show that the proposed EDCT-OFDM-IM system exhibits better bit error rate performance over the conventional DFT-OFDM-IM and DCT-OFDM-IM counterparts.