Dual Mode OFDM-IM with Multiple Choice of Constellations

Abstract

Orthogonal frequency division multiplexing is a multicarrier digital modulation technique that is extensively used in modern wireless communication systems. Index Modulation combined with orthogonal frequency division multiplexing lead to improved spectral efficiency. Dual mode orthogonal frequency division multiplexing with index modulation aims at increasing spectral efficiency even further. The improved spectral efficiency comes at a cost of increased signal detection complexity at receiver side. Here we propose yet another index modulation aided dual mode orthogonal frequency division multiplexing technique where the two modes can be selected from a set of four modes or constellations. By doing this we increased the proportion of index bits compared to data bits, eventually leading to an increase in spectral efficiency. This paper describes in detail our proposed method, the accompanying transmission and receiver detection technique. We also illustrate the spectral and energy efficiency of proposed technique and compare its performance with its nearest counterparts.