Beamforming Design for Ultra-Reliable and Low-Latency Communication in 5G

Ultra Reliable and low-latency communication (URLLC) is one of the major challenges of the fifth generation (5G) communication networks. URLLC can enable several new applications, e.g., remote examination of patients, remote operation of of heavy industrial machines, haptic feedback, vehicle-to-vehicle communication, driverless cars, experiencing 360-degree view of a live sports game from home via virtual reality handset, or factory automation. However, realization of URLLC system is quite challenging as two conflicting requirements, low-latency (low-delay) and ultrahigh reliability, are under expectation. Low latency requirements mandate short-packet communication which in turn severely degrades the channel coding gain or the reliability. On the other hand, securing reliability demands for more resources (e.g., parity, redundancy, and retransmissions) which in turn increases latency. This project aims to consider a communication between multiple-antenna source and multiple users under low-latency and ultra-reliability constraints. This requires joint design of transmit beamforming vectors for multiple users. Our objective is to maximize the users minimum throughput subject to transmit power constraints. To reduce latency, short frame structure, or short blocklength communication, has to be adopted, which will result in short channel codes. Under short blocklength regime, the achievable rate is a complicated function of beamforming vectors, the blocklength and the decoding error probability. Due to the complexity of that expression, the resulting resource allocation problem (or beamforming design problem in case of multiuser multiple-antenna transmission) is highly non-convex and challenging to solve. This would necessitate the detail study of required methodologies and convex/concave bounds to approximate the original non-convex problem by a convex optimization problem. The project aims to solve this challenging problem to realize a multiuser URLLC system. The performance of the proposed algorithm will be analyzed through rigorous simulations.