Reflective Group Number Based Index Modulation for Intelligent Reflecting Surface Assisted Wireless Communications

Thanks to the characteristic that the signals can be reflected to a pre-defined oritention, intelligent reflecting surface (IRS) is becoming a promising technology to improve the efficiency of wireless communications. In this paper, a reflective group number based index modulation (RGNIM) scheme is proposed by exploiting the activating states of the reflecting elements of the IRS, where different group number of activated IRS elements can carry additional information in the reflective domain. The bit error ratio (BER) performance is then theoretically analysed under the imperfect channel estimation by adopting the maximum likelihood (ML) detection approach. Simulation results validate and evaluate the BER performance of the RGNIM assisted system, which also demonstrate that our RGNIM scheme outperforms other IRS aided index modulation schemes.