Optimal power allocation for the multiple-sensor single-DF relay based IoT networks under transceiver hardware impairments

Accurate system modeling is a crucial requirement while realizing efficient and reliable communication over Internet of Things (IoT) infrastructure. The assumption of ideal hardware causes huge deviation in the performance of systems as estimated from such theoretical models and their practical implementations. In this paper, we study this fact over N pairs of source and destination IoT devices/nodes having non-interfering channels with a half-duplex decode-and-forward relay node. The relay assists the communication between N source-destination pairs. Specifically, we first derive the outage probability expression for the considered system with transceiver hardware impairments under independent but not identically distributed Rayleigh fading channels. Then, taking the transceiver hardware impairments and power and outage constraints into account, we formulate and investigate an optimal power allocation strategy in order to minimize the source-sum-power consumption using Karush-Kuhn-Tucker (KKT) conditions. With the aid of numerical investigations, the optimality of the proposed strategy is illustrated. It is observed that the power consumption depends on the number of sources and increases with the increased number of sources. In addition, the transceiver hardware impairments have detrimental impacts on the source-sum-power consumption of the considered system. Our results also reveal that the proposed scheme outperforms the uniform power allocation scheme for various involved parameters. (c) 2020 Elsevier B.V. All rights reserved.