Hybrid OFDM-IM System for BER Performance Improvement

OFDM-IM is modulation technique which is able to outperform classical OFDM modulation in terms of spectral and energy efficiency, by exploiting concept of Index Modulation (IM). However, this improvement can be achieved at the expense of worse bit-error-rate (BER) performance for the low to medium signal-to-noise ratio (SNR) values, while for the high SNRs it outperforms OFDM system in terms of BER. Thus, in this paper, we propose a hybrid system for BER minimization, which assumes implementation of OFDM-IM at high SNR values, and classical OFDM at lower SNR values, all based on the known channel characteristics.