Novel Power Control With Duplex Mode Selection Schemes in Two-Way IoT-Type Communication

This article presents an optimization strategy for an Industrial Internet of Things (IoT) configuration, with particular emphasis on the enhancement of spectrum efficiency (SE) and reliable connectivity. Our analysis delves into the intricacies of a communication model designed to facilitate the concurrent exchange of information between sensor-cum-actuator nodes and a controlling station through the shared spectrum of a licensed cellular network. Pairing between the controller and any sensor-cum-actuator node is facilitated by a simple opportunistic selection mechanism that does not involve additional channel overheads. To improve SE, all IoT nodes are equipped with full-duplex (FD) functionality, while reliability is improved by making the network adaptive. The transmit powers of IoT nodes are chosen by apportioning the interference temperature limit (ITL), in a manner that cumulative interference caused to the cellular network does not exceed the ITL. Under this constraint, the random transmit powers induce significant signal-to-noise ratio variations, which we exploit through adaptive network strategies involving careful choice of transmit powers and switching between FD and half-duplex (HD) modes, for optimal performance. We establish that adaptation is more effective when assisted by instantaneous channel knowledge, which leads to the evolution of the statistically optimum scheme (SOS), local channel aware scheme (LCAS), and the global channel aware scheme (GCAS) in this article. Analysis is presented for network throughput for each of the evolved schemes, and critical parameters responsible for adaptation are presented in closed-form. The accuracy of our analytical findings is verified through computer simulations.