In orthogonal frequency division multiplexing relying on subcarrier index modulation (OFDM-SIM). the information is conveyed by both the indices of the activated subcarriers and the conventional amplitude-phase modulated (APM) symbols. It has been shown that OFDM-SIM is capable of striking a tradeoff between the attainable spectral efficiency (SE) and energy efficiency (EE). In order ... https://www.freaknleather.com/product-category/ratchet-strap/