Time-Indexed Media-Based Modulation

Abstract

Media-based modulation (MBM) is a promising modulation scheme which is attracting recent research attention. In MBM, radio frequency (RF) mirrors are used to create a channel modulation alphabet based on the ON/OFF (i.e., transparent/opaque) status of these mirrors. The index of the mirror activation pattern in a channel use conveys information bits in addition to the bits conveyed through conventional modulation symbols. MBM has been shown to achieve improved performance compared to conventional modulation schemes. In this paper, we introduce time-slot indexing to MBM,which further improves the performance. The proposed time-indexed MBM (TI-MBM) is a block transmission scheme, where a time slot in a given frame can be used or unused, and the choice of the slots used for transmission conveys time-index bits. We study the proposed TI-MBM scheme in frequency-selective channels and show that TI-MBM achieves better performance compared to conventional MBM. Further, recognizing that the TI-MBM signal structure promotes sparsity, we exploit the use of sparse recovery algorithms for the detection of TI-MBM signals. We show that compressive sampling matching pursuit (CoSaMP) and subspace pursuit (SP) based TI-MBM signal detection can achieve significantly improved performance compared to conventional minimum mean square (MMSE) detection.