Lyapunov Drift-Based Scheduling for Short-Packet Transmission with Finite Blocklength Coding

Ultra-Reliable and Low-Latency Communication (URLLC) has attracted considerable attention because it has great potential in industrial automation and autonomous driving. As one of the promising techniques to solve the low-latency problem, finite blocklength coding has been a critical topic. How to reduce the delay with the finite blocklength coding in the URLLC system is a challenging issue. In this paper, a Lyapunov drift-based scheduling scheme is presented for short-packet transmission systems. Specifically, a scheduling scheme is designed to determine the transmission rate and maximize the system throughput with Lyapunov optimization. The average power constraint can be tackled with the virtual power queue method. So that the short-packet transmission problem can be formulated as a univariate optimization problem, which is non-convex. A sub-optimal solution to this optimization problem can be obtained by our presented algorithm, which ignores the higher order terms of the Taylor series. Through simulations, the performance of our proposed algorithm is shown to be very close to that of the optimal policy obtained by the exhaustive search algorithm.