Transmission Power Allocation of RIS-Aided Cell-Free mMIMO for Downlink URLLC Service

Cell-free Massive MIMO is a potential technology direction of the beyond-5G network, which can achieve higher network capacity and energy efficiency. The distributed nature of reconfigurable intelligent surface (RIS) deployment has natural compatibility with cell-free networks, and RIS has the potential to reduce the cost of the network. This paper studies the downlink transmission power allocation in a RIS-Aided cell-free massive MIMO network for Ultra reliable and low-latency communication (URLLC). We propose a scheme that considers joint RIS optimization and downlink power allocation to optimize the sum URLLC achievable rate. Numerical results show that the sum URLLC achievable rate of RIS-Aided cell-free massive MIMO is enhanced further with the assistance of RIS and the optimization scheme proposed in this paper.