Rateless-Code-Based Secure Cooperative Transmission Scheme for Industrial IoT

Integrating the Internet-of-Things (IoT) paradigm with industrial wireless sensor networks (IWSNs) has led to a technological evolution known as Industrial IoT (IIoT). To ensure reliable, secure, and low-latency communication in IIoT applications like healthcare, we use rateless codes (RCs) for forward error correction (FEC) at the physical layer (PHY) in a cooperative delay-constrainted environment. Probability of violation (Pr_vio) is used as a performance metric which consists of: 1) reliability outage probability, i.e., the probability with which the information cannot be successfully decoded within the time constraint T and 2) information intercept probability, which reflects the secrecy performance. Since RC can adjust the rate on the fly, we analyze the performance when relay transmits a fraction of the message and the receiver does energy accumulation (EA). We derive a closed-form expression of Pr_vioin a single-relay system at a high signal-to-noise ratio (SNR) when the receiver either accumulates energy or mutual information (MI) from the received signals. Furthermore, Pr_vio of various relay selection schemes is evaluated in a multirelay system. Such kind of analysis in which relay selection is done using RC for PHY-FEC is first of its kind and it is compared to fixed-rate codes. Overall, results show the significant benefits of PHY-RC for guaranteeing the Quality-of-Service (QoS) requirements essential in IIoT applications.