Optimizing Resource Allocation in URLLC for Real‐Time Wireless Control Systems

As one of the three main scenarios in fifth generation (5G) cellular networks, ultra‐reliable and low‐latency communication (URLLC) can serve as an enabler for real‐time wireless control systems. In such a system, communication resource consumption in URLLC and control subsystem performance are mutually dependent. To optimize the overall system performance, it is critical to integrate URLLC and control subsystems together by formulating a co‐design problem. Based on uplink transmission, this chapter studies the problem of resource allocation for URLLC in real‐time wireless control systems. The problem is conducted by optimizing bandwidth and transmission power allocation in URLLC and control convergence rate subject to the constraints on communication and control. To formulate and solve the problem, this chapter first converts the control convergence rate requirement into a communication reliability constraint. Then, the co‐design problem can be replaced by a regular wireless resource allocation problem. By proving that the converted problem is concave, an iteration algorithm is proposed to find the optimal communication resource allocation. Based on that, the optimal control convergence rate can be obtained to optimize overall system performance. Simulation results show remarkable performance gain in terms of spectral efficiency and control cost. Compared with the scheme of satisfying fixed quality‐of‐service in traditional URLLC design, the proposed method in this chapter can adjust optimal spectrum allocation to maximize the communication spectral efficiency and maintain the actual control requirement.