Wireless Communication Design And Verification For Real-time Control Systems

Recently,with the rise of emerging technologies such as the Internet of Things,tactile Internet,and cyber-physical systems,people can interact with the physical world in real-time.These emerging applications implement real-time control of physical systems through wireless network control systems.However,since real-time control usually has super high reliability and ultra-low latency performance requirements,current wireless communication systems are far from sufficient to support real-time control.In the upcoming fifth generation(5G)cellular network,ultra-reliable and low-latency communication(URLLC)is considered as an essential service for real-time wireless control systems.However,the extremely high quality of service(QoS)in URLLC causes a lot of wireless resource consumption.In addition,in the real-time wireless network control system,the tight coupling between communication and control requires us to treat the wireless and control systems as a whole.Therefore,this article will use the integrated design of communication and control,focusing on the research of the wireless transmission mechanism in the real-time wireless network control system based on URLLC.The main contents and innovations are as follows:(1)State-aware wireless transmission design: Our goal is to reduce significant wireless resource consumption in URLLC by dynamic QoS wireless transmission design,while maintaining the good control performance of the real-time wireless control system.Specifically,we propose a state-aware dynamic QoS transmission method to reduce the number of URLLC transmissions with high QoS,and a wireless resource allocation method to guarantee successful transmission at each moment,where we formulate twe optimal problems:(1)an optimal problem to minimize control costs by dynamic QoS allocation transmission;(2)an optimal problem to minimize the packet error probability by resource allocation to ensure the optimal wireless transmission of dynamic QoS problem.Then,we adopt an expectation substitution to solve the first optimal problem and prove that the second problem is convex.Finally,state-aware dynamic transmission and resource allocation can be obtained accordingly.Simulation results show the preformance of our method.(2)Channel-aware wireless transmission design: In the URLLC-based real-time wireless network control system,the communication resource consumption in URLLC and the performance of the control subsystem are interdependent.In order to optimize the overall system performance,it is essential to integrate URLLC and the control subsystem by asking a collaborative design question.Specifically,we propose a control-constrained communication optimization algorithm to achieve real-time control.The problem is to minimize the power consumption of the device by optimizing wireless transmission and resource allocation under the constraints of ensuring system control performance.To solve this problem,we first convert the control convergence rate requirements into communication reliability constraints.Then,the optimal problem of communication control collaborative design is transformed into a conventional optimal radio resource allocation problem.The Lagrangian dual method is used to solve the optimal problem to obtain the best wireless transmission strategy and resource allocation scheme.Simulation results show that,this method can effectively reduce communication energy consumption,while maintaining good control performance.