Cognitive Interference Alignment Schemes for IoT Oriented Heterogeneous Two-Tier Networks

Abstract

This paper considers interference management and capacity improvement for Internet of Things (IoT) oriented two-tier networks by exploiting cognition between network tiers with interference alignment (IA). More specifically, we target our efforts on the next generation two-tier networks, where a tier of femtocell serving multiple IoT devices shares the licensed spectrum with a tier of pre-existing macrocell via a cognitive radio. Aiming to manage the cross-tier interference caused by cognitive spectrum sharing as well as ensure an optimal capacity of the femtocell, two novel self-organizing cognitive IA schemes are proposed. First, we propose an interference nulling based cognitive IA scheme. In such a scheme, both co-tier and cross-tier interferences are aligned into the orthogonal subspace at each IoT receiver, which means all the interference can be perfectly eliminated without causing any performance degradation on the macrocell. However, it is known that the interference nulling based IA algorithm achieves its optimum only in high signal to noise ratio (SNR) scenarios, where the noise power is negligible. Consequently, when the imposed interference-free constraint on the femtocell can be relaxed, we also present a partial cognitive IA scheme that further enhances the network performance under a low and intermediate SNR. Additionally, the feasibility conditions and capacity analyses of the proposed schemes are provided. Both theoretical and numerical results demonstrate that the proposed cognitive IA schemes outperform the traditional orthogonal precoding methods in terms of network capacity, while preserving for macrocell users the desired quality of service.

Interference Management in 5G and Beyond Network: Requirements, Challenges and Future Directions

“…In [184], the authors discussed interference management and capacity enhancement of two-tier IoT networks. The sole purpose of their investigation is to control the cognitive interference effect on the macro cell besides maintaining the femtocell's optimal capacity.…”

“…The research is completely based on physical layer aspects. In the future, use the same resources to investigate the network layer [184] Advanced highly secure data transfer over IoT system A new method was developed in which a transmitter Alice communicates with a receiver Bob covertly by avoiding the Warden Willie…”

Partial Interference Alignment Scheme for Three-Tier Downlink Heterogeneous Networks

“…[24] proposes the public safety users priority-based mobile personal cells user association scheme to reduce co-channel interference. For the two-tier HetNets which are oriented to the Internet of Things, [25] proposes two self-organizing cognitive IA solutions, which mainly eliminate the cross-tier interference caused by cognitive spectrum sharing and ensure the optimal capacity of small cells. [26] deploys a D2D local area network in the service area of the MBS to form a HetNet, and proposes two D2D communication schemes based on IA to manage the co-tier and cross-tier interference.…”

An Active Power Control Technique for Downlink Interference Management in a Two-Tier Macro–Femto Network

“…Thus, HeNB power should be carefully tuned for reducing the CO2 emissions but still maintaining QoS of the user. In this scenario, adaptive, active and cognitive resources management techniques can be the advanced solution rather than conventional resources management and customary cell planning [18,19].…”