Multiuser Downlink Beamforming for URLLC in the Short Blocklength Regime

Ultra reliable and low latency communication (URLLC) becomes one of the key requirements for the next-generation wireless networks to enable high-stake applications such as autonomous driving and industrial internet of things. This paper considers the multiuser downlink problem for URLLC in the short blocklength regime. Due to the complexity of the achievable data rate expression under the short blocklength regime, the weighted sum rate optimization problem become extremely challenging to be solved. To deal with the highly intractable nonconvex problem, the paper develops an efficient iterative optimization algorithm via the uplink-downlink duality theory for the beamforming vectors direction design, followed by the geometric programming method for the associated power allocation via lower bounding the achievable data rate. Simulation results demonstrate the achievable performance and low computational complexity of the proposed algorithm.