Zero Padded Dual Index Trimode OFDM-IM

Future demands on higher data rate services and green communication systems expect higher spectral efficiency and energy efficiency respectively. The OFDM-IM is considered as one of the solutions in this direction. Even though it offers better energy efficiency, it requires further improvements in spectral efficiency particularly on the use of higher-order modulations. The recent research interests provide solutions by increasing the number of bits used for indexing. In this work, a zero padded approach has been used to improve energy efficiency and dual indexing with tri-mode has been introduced to improve the spectral efficiency by 0.25 bpcu for 50% of carrier use. The simulation results have proved the improvement in error performance along with an increment in spectral efficiency.