Finite-Blocklength RIS-Aided Transmit Beamforming

TL;DR

This paper proposes a joint design of transmit beamforming and RIS configuration to optimize the geometric mean rate in ultra-reliable low-latency communication systems with finite blocklength, ensuring fairness and reliability.

Contribution

It introduces a novel joint optimization algorithm for beamformers and RIS elements in the finite blocklength regime, enhancing rate fairness and reliability.

Findings

The proposed algorithm improves feasible rate points.

Simulation results demonstrate the effectiveness of the joint design.

The method ensures fair and reliable links for all users.

Abstract

This paper considers the downlink of an ultra-reliable low-latency communication (URLLC) system in which a base station (BS) serves multiple single-antenna users in the short (finite) blocklength (FBL) regime with the assistance of a reconfigurable intelligent surface (RIS). In the FBL regime, the users' achievable rates are complex functions of the beamforming vectors and of the RIS's programmable reflecting elements (PREs). We propose the joint design of the transmit beamformers and PREs, the problem of maximizing the geometric mean (GM) of these rates (GM-rate) and show that this aforementioned results are providing fair rate distribution and thus reliable links to all users. A novel computational algorithm is developed, which is based on closed forms to generate improved feasible points, using its execution. The simulations show the merit of our solution.