Core Concepts
The core message of this article is to analyze the secrecy performance of an RIS-assisted multiuser massive MIMO system, considering the impact of channel state information (CSI) imperfection, reconfigurable intelligent surface (RIS) phase noise, spatial correlation, and transceiver hardware impairments.
Abstract
The article investigates the integration of an RIS into a secure multiuser massive MIMO system in the presence of transceiver hardware impairments, imperfect CSI, and spatially correlated channels.
Key highlights:
- A linear minimum-mean-square error estimation algorithm is introduced to estimate the aggregate channel by considering the impact of transceiver hardware impairments and RIS phase-shift errors.
- A lower bound for the achievable ergodic secrecy rate is derived in the presence of a multi-antenna eavesdropper when artificial noise is employed at the base station.
- The obtained expressions of the ergodic secrecy rate are further simplified in some special cases to obtain valuable insights.
- A power allocation optimization strategy between the confidential signals and artificial noise is presented to counteract the effects of hardware impairments.
- The analysis reveals that a non-zero ergodic secrecy rate is preserved if the total transmit power decreases no faster than 1/N, where N is the number of RIS elements.
- The ergodic secrecy rate grows logarithmically with the number of base station antennas M and approaches a certain limit in the asymptotic regime Nāā.
Stats
The number of RIS elements N.
The number of base station antennas M.
The number of legitimate users K.
The number of eavesdropper antennas ME.
Quotes
"The ergodic secrecy rate grows logarithmically with the number of BS antennas M and approaches a certain limit in the asymptotic regime Nāā."
"The analysis reveals that a non-zero ergodic secrecy rate is preserved if the total transmit power decreases no faster than 1/N, where N is the number of RIS elements."