Multidimensional Modulation Method based on Grouped Subcarrier Index Modulated OFDM

In order to solve the problem of spectrum efficiency loss caused by grouped modulation in subcarrier index modulated OFDM system, a multidimensional modulation method based on grouped subcarrier index modulated OFDM is proposed. This method makes the number of silent subcarriers as an extra modulation dimension, so as to increase the number of bits carried on SIM-OFDM symbol and improve the spectrum efficiency of the system. According to the simulation result, although the BER of multidimensional modulated GSIM-OFDM system is a little higher than that of traditional GSIM-OFDM system, the spectrum efficiency of the system with the proposed method is also better than that of the system with traditional grouped modulation method. What's more, the more groups, the more obvious the advantage of spectrum efficiency.