Performance of Dual mode OFDM-IM using Reduced Complexity Receiving Technique

Dual-Mode Index modulated Orthogonal Frequency Divison Multiplexing is a technique, which eliminates the spectral efficiency limitations of standard index modulated Orthogonal Frequency Divison Multiplexing. This dual mode technique improves spectral efficiency by using all subcarriers for information transmission. The subcarriers are divided into several smaller sub-blocks. There are two groups of subcarriers in every sub-block based on index bits, known as active subcarriers and inactive subcarriers. The active subcarriers are modulated by primary signal constellation and inactive subcarriers are modulated by a secondary signal constellation. The information carrying bits include, bits corresponding to classic signal constellation symbols which actually travel through the wireles channel and also the index bits that are used for indexing the active subcarriers. In this paper we have analysed the BER performance of the above modulation technique for different system parameters with the aim of having an energy efficienct as well as spectrally efficient signalling scheme with a simple receiving technique.