Secure and Reliable IoT Communications in Underlay CRN with Imperfect CSI

The Internet of Things (IoT) is a rapidly growing network of interconnected devices that has the potential to revolutionize many industries and sectors. However, IoT devices are often vulnerable to security and reliability threats due to their limited resources and the challenging environments in which they are deployed. This study proposes a secure and reliable cognitive radio network (SAR-CRN) architecture for IoT applications. Leveraging cognitive radio (CR) capabilities, SAR-CRN enables efficient spectrum sharing between primary users and resource-limited IoT devices. We propose a two-step relay selection scheme that identifies the optimal relay node capable of correctly decoding the information and retransmitting it with the highest secrecy rate. More specifically, this scheme optimizes relay selection for enhanced security and reliability within the SAR-CRN framework. The performance of the proposed SAR-CRN system is evaluated using a variety of metrics, including the probability of correct decoding ability, and the average secrecy capacity (ASC) and secrecy outage probability (SOP) under both known and unknown channel state information (CSI) scenarios. The result analysis demonstrates that the proposed SAR-CRN system significantly outperforms conventional CR networks (CRNs) in terms of security and reliability, paving the way for secure and reliable communication in resource-constrained IoT environments.