IEEE Transactions on Green Communications and Networking
A. Bhowal, S. Aïssa and R. S. Kshetrimayum, "RIS-Assisted Advanced Spatial Modulation Techniques for Ambient Backscattering Communications,," IEEE Transactions on Green Communications and Networking, vol. 5, no. 4, pp. 1684-1696, Dec. 2021.
Abstract:
The dynamic control of wireless channels is a
trending field of research which has been made possible by the
advent of metamaterial-based reconfigurable intelligent surfaces
(RIS). Moreover, for future applications in 5G and beyond,
the device size constraints and power supply issues also need
to be resolved before RIS can be deployed at large scale.
Keeping these problems in mind, we propose RIS-assisted ambient
backscattering (ABSc) communication framework utilizing
advanced spatial modulation (ASM) techniques for spectral- and
energy-efficient communication. Here, ABSc technique is
leveraged for harnessing the power from ambient RF waves,
while ASM techniques are deployed to ensure high spectral
efficiencies by activating more than one but not the full set
of antennas for transmission. Extensive performance analysis
of ASM techniques are carried out, and upper-bounds on the
ensuing error rates are derived. We corroborate the error
rate upper-bound results with Monte-Carlo simulation results,
and also provide comparative results to reveal the benefits of
the proposed framework. In particular, it is shown that the
ASM technique of improved quadrature spatial modulation
(IQSM) can achieve the highest spectral efficiency. All the
ASM techniques can perform better than the conventional
spatial modulation technique by offering signal-to-noise power
ratio gains of more than 2 dB. Additionally, RIS-assisted ASM
techniques with ABSc perform better than the conventional
frameworks without RIS.