Variable Active Antennas-Aided Channel Modulation

Recently, utilizing the indexes of channel states, media-based modulation (MBM) has been viewed as a potential key technique for enhancing the reliability of communication systems. In addition, the available combinability of active transmit antennas (TAs) is a potential method for exploiting more additional information. In this letter, a new design, called as the variability of active antennas for the channel modulation (VA-CM), is proposed to further improve the communication quality. In the VA-CM, the in-phase and quadrature antenna index (AI) vector sets, which contain all possible vectors of active TA(s) (including the case of 0 active TA), are respectively designed. Then, with the I/Q AI bits, the in-phase/quadrature (I/Q) AI vector from the I/Q vector set is specified and its components are respectively multiplied by specified I/Q channel index (CI) vectors with
${n_{\mathrm {rf}}}$
I/Q CI bits, into one MBM signal vector. Meanwhile, in order to avoid the unrecoverable detection, with the control of the specified AI vector number with all zero I/Q AI bits, another CI vector set in one CI Vector Selector, which contains
$2^{n_{\mathrm {rf}}}$
CI vectors of selecting two channel states, is selected for forming one non-zero MBM signal vector. Finally, the spectral efficiency and the average bit error probability (BEP) are analyzed. Simulation results show that the VA-CM outperforms other schemes in terms of the BEP performance.