Pre-Compensation-Assisted Generalized Beam Index Modulation (PC-GBIM) for mmWave Massive MIMO Over Doubly Selective Channels

To better serve future vehicular network, we judiciously design an anti-Doppler index modulation termed as pre-compensation assisted generalized beam index modulation (PC-GBIM) for wideband mmWave massive multiple-input multiple-output (mMIMO) systems. The proposed PC-GBIM design comprises two key elements. First, we generalize the existing beam index modulation (BIM) from the hybrid narrowband to hybrid wideband systems and from activating single beam to activating multiple beams. Secondly, an effective first-order Doppler pre-compensator is introduced to assist index modulation, such that the originally complicated block-based maximum likelihood (ML) detection degenerates into the simple subcarrier-based ML detection. Both the theoretical analyses and numerical simulations have been made and demonstrate the superiority over existing alternatives in doubly-selective channels.