Intelligent Reflecting Surface-aided URLLC in a Factory Automation Scenario

Different from conventional wired line connections, industrial control through wireless transmission is widely regarded as a promising solution due to its reduced cost, increased long-term reliability, and enhanced reliability. However, mission-critical applications impose stringent quality of service (QoS) requirements that entail ultra-reliability low-latency communications (URLLC). The primary feature of URLLC is that the blocklength of channel codes is short, and the conventional Shannon's Capacity is not applicable. In this paper, we consider the URLLC in a factory automation (FA) scenario. Due to densely deployed equipment in FA, wireless signal are easily blocked by the obstacles. To address this issue, we propose to deploy intelligent reflecting surface (IRS) to create an alternative transmission link when the direct link is blocked, which can enhance the transmission reliability. In this paper, we focus on the performance analysis for IRS-aided URLLC-enabled communications in a FA scenario, where the direct link is blocked. Both the average data rate (ADR) and the average decoding error probability (ADEP) are derived under the case with perfect channel state information (CSI) and the case without CSI. Asymptotic analysis is performed to obtain more design insights. Extensive numerical results are provided to verify the accuracy of our derived results.