Hardware- and Interference-Limited Cognitive IoT Relaying NOMA Networks With Imperfect SIC Over Generalized Non-Homogeneous Fading Channels

Abstract

Internet-of-Things (IoT) technology has received much attention due to its great potential to interconnect billions of devices in a broad range of applications. IoT networks can provide high-quality services for a large number of users and smart objects. On the other hand, massive connectivity in IoT networks brings problems associated with spectral congestion. This issue can be solved by applying cognitive radio (CR) and non-orthogonal multiple access (NOMA) techniques. In this respect, this paper studies the performance of cooperative CR-NOMA enabled IoT networks over a generalized α − µ fading channel model. Closed-form analytical expressions of the end-to-end outage probability (OP) for the secondary NOMA users are derived using the Meijer's G-function with a consideration of the impacts of the interference temperature constraint, primary interference, residual hardware impairments and imperfect successive interference cancellation. Moreover, to acquire some useful insights on the system performance, asymptotic closed-form OP expressions are provided. Additionally, the impact of α and µ fading parameters on the outage performance is examined and, as a result, it is concluded that the system performance sufficiently improves as α and/or µ increase. Furthermore, the outage performance of the proposed system model is shown to outperform that of an identical IoT network operating on orthogonal multiple access. Finally, the provided closed-form OP expressions are validated with Monte Carlo simulations. INDEX TERMS α − µ fading, cognitive radio (CR), cooperative communications, Internet-of-Things (IoT), non-homogeneous generalized fading, non-orthogonal multiple access (NOMA), outage probability (OP).

Physical Layer Security in NOMA-Enabled Cognitive Radio Networks With Outdated Channel State Information

“…Besides CR, the key idea of NOMA is to encourage spectrum sharing among multiple users within one resource block by exploiting power domain multiplexing [10], [11]. Considering both technologies have good application prospects, some researches have combined NOMA and underlay CR appropriately to reduce interference and make better use of the spectrum resources [12]- [16].…”

Impact of Residual Hardware Impairment on the IoT Secrecy Performance of RIS-Assisted NOMA Networks

“…I NTERNET of Things (IoT) technology is getting a lot of attention because of its huge potential to connect billions of devices in numerous applications [1]. Driven by economic and environmental concerns, and the scale of the next-generation IoT system, the design of energy-efficient high bandwidth wireless technology is becoming crucial [2].…”

“…The RIS can be easily embedded into the interior of buildings and onto the surface of large vehicles not need to change the hardware and software of the device, making IoT performance improvements in connectivity, power, and coverage significantly less costly [9,10]. Meanwhile, RIS can achieve a large range of coverage under low power consumption [1].…”

Cognitive Non-ideal NOMA Satellite-Terrestrial Networks with Channel and Hardware Imperfections

“…In [6]- [8], the underlay CR and NOMA were jointly studied aiming at reducing the interference and more effective spectrum utilization. For example, in [6], the authors evaluated the outage performance of CR-NOMA by considering an amplify-and-forward relaying scheme while a similar system model was examined for the detect-and-forward scheme over generalized α − μ fading channels [7], [8].…”

“…In the real-time communication, the use of multiple NOMA users may not be achievable because the processing complexity of the SIC at receivers raises in a non-linear manner by the increased number of users[21]. Moreover, when the SIC error propagates, this complexity gets to be more vital[7].…”