A Generalization of Multiple-Mode OFDM with Index Modulation

In this paper, we propose the scheme of generalized multiple-mode orthogonal frequency division multiplexing with index modulation (GMM-OFDM-IM), which allows a different subcarrier to utilize a signal constellation of a different size while conveying the same number of IM bits. Considering phase shift keying (PSK) constellations, we present design guidelines for GMM-OFDM-IM to achieve the optimal error performance in the asymptotically high signal-to-noise ratio region. A computationally efficient and near-optimal detector based on the idea of sequential decoding is also tailored to GMM-OFDM-IM to avoid the detection of an illegimate constellation permutation. Monte Carlo simulations are conducted to examine GMM-OFDM-IM, whose inherent properties and advantages are revealed by the simulation results.