Pairwise Sequency Index Modulation with OTSM for Green and Robust Single-Carrier Communications

In this letter, inspired by the fundamental thoughts of sequency index modulation (SeIM) and orthogonal time sequency multiplexing (OTSM), a novel technique is introduced for green and robust single-carrier communications in wireless networks. More specifically, pairwise SeIM (PSeIM) is proposed as a novel indexing scheme making SeIM robust to error propagation and significantly reduces the peak power of SeIM-based systems with a lower complexity of detection. Analytical results are presented for the bit error rate (BER), peak-to-average power ratio (PAPR), and spectral efficiency to reveal the trade-off and advantages in PSeIM-OTSM. Simulation and analytical results verify that for 4-QAM uncoded data, PSeIM-OTSM outperforms OTSM by 50% in terms of both PAPR and complexity of detection along with 125.32% energy efficiency improvement to achieve a BER of 10-8 in high mobility doubly spread channels.