OFDM with Double Quadrature Signed Index Shift Keying

Spectral, and energy-efficient, communication is essential for the current future wireless generations. Therefore a novel OFDM with double quadrature signed index shift keying (OFDM-DQSISK) proposed. Double levels of (ISK) system proposed to enhance spectral efficiency modulation (OFDM-IM) system. In DQSISK level one, variable α its jα are exploited differentiate between indices active in-phase quadrature-phase subcarriers, respectively. While versions, i.e., -α -jα, in two distinguish subcarrier indices. both levels, all possible combinations, including case inactive DQSISK. Hence, improved as it linearly increases grouping size. Also, value optimized over structure using Grey Wolf Optimizer (GWO) minimize scheme’s peak average power ratio (PAPR). Furthermore, replaced standard M-ary Plus amplitude (PAM) introduce higher SE version The simulation results illustrate superiority, attains low PAPR compared up-to-date OFDM-IM schemes.