BER Perfomance of OFDM-IM System in Fading Channels

Abstract

Orthogonal frequency division multiplexing (OFDM) with index modulation (IM) is a recently proposed modulation technique for performance improvement of OFDM based systems. The basic concept of this modulation scheme assumes that the information is conveyed to the receiver by standard M-ary signal constellations and, at the same time, by the indices of the active OFDM subcarriers which are chosen for carrying those constellation symbols. Due to the additional information bits transmitted in that way, spectral efficiency of the system is increased, as well as energy efficiency, because not all OFDM subcarriers are active in transmission. However, these performance improvements are achieved at the price of bit error rate (BER) degradation at lower signal-to-noise ratio (SNR) values. In this paper we examine BER performance of OFDM-IM system in case of frequency selective fading channels, assuming both Rayleigh and Rician fading statistics.