Multiple-Antenna Weibull-Fading Wireless Communications Enhanced by Reconfigurable Intelligent Surfaces

The Reconfigurable Intelligent Surface (RIS) has recently gained traction as a promising, enabling technology for future sixth-generation (6G) mobile networks. Thereby, this paper presents a comprehensive statistical, secrecy, and performance analysis of RIS-assisted multiple-antenna wireless communication systems under Weibull fading. The system model encompasses an antenna array at the source transmitting to a typical single-antenna user through both a generally weaker direct link and an enhanced RIS-aided double-Weibull-fading linear cascaded communication channel. Moreover, the RIS is assumed to perform constructive interference towards the user through realistic non-ideal phase cancellation with residual phase errors that follow the von Mises distribution. Then, the statistical distribution of the resultant channel fading is accurately modeled by the analytically derived moment-generated Gamma distribution in conformity with the central limit theorem (CLT). While considering the existence of a malicious eavesdropper directly linked with the source, relevant performance metrics, expressly the secrecy outage probability (SOP), the symbol error rate (SER), and the spectral efficiency of the system, have their expressions determined for the specific Weibull-fading scenario and verified by Monte Carlo simulations. The study highlights the significant performance improvement of the system arising from a larger number of antenna elements of the RIS, as well as through a more accurate phase cancellation response associated with a higher von Mises concentration parameter,
$\kappa $
. Furthermore, the effects of diverse fading scenarios and varying line-of-sight (LoS) propagation strength are evaluated through the Weibull shape parameter,
$k$
.