Reconfigurable Intelligent Surface-Aided Time Reversal Wireless Systems

Time reversal (TR) has the potential to revolutionize wireless communication, owning to its capabilities to focus the signal energy in both time and space domains. Nevertheless, its performance is highly affected by the richness of the multipath channel, which is highly degraded in sparse multipath environments. Therefore, in this paper, we aim to address this issue by leveraging reconfigurable intelligent surfaces (RISs) to artificially create rich scattering environments. We investigate the performance gain of RIS-assisted TR by adjusting the RIS parameters to efficiently realize artificially rich multipath fading. The simulation results demonstrate the effectiveness of integrating RIS with TR in sparse multipath environments, in terms of the bit error rate and channel capacity. Finally, we quantify the performance degradation of the proposed RIS-assisted TR under the effect of channel estimation errors. It is shown that imperfect channel state information has a significant impact on the performance of the proposed scheme.