Full-Duplex Cloud Radio Access Network: Stochastic Design and Analysis

Full-duplex (FD) has emerged as a disruptive communications paradigm for enhancing the achievable spectral efficiency (SE), thanks to the recent major breakthroughs in self-interference (SI) mitigation. The FD versus half-duplex (HD) SE gain, in cellular networks, is however largely limited by the mutual-interference (MI) between the downlink (DL) and the uplink (UL). A potential remedy for tackling the MI bottleneck is through cooperative communications. This paper provides a stochastic design and analysis of FD enabled cloud radio access network (C-RAN) under the Poisson point process (PPP)-based abstraction model of multi-antenna radio units (RUs) and user equipments (UEs). We consider different disjoint and user-centric approaches towards the formation of finite clusters in the C-RAN. Contrary to most existing studies, we explicitly take into consideration non-isotropic fading channel conditions and finite-capacity fronthaul links. Accordingly, upper-bound expressions for the C-RAN DL and UL SEs, involving the statistics of all intended and interfering signals, are derived. The performance of the FD C-RAN is investigated through the proposed theoretical framework and Monte-Carlo (MC) simulations. The results indicate that significant FD versus HD C-RAN SE gains can be achieved, particularly in the presence of sufficient-capacity fronthaul links and advanced interference cancellation capabilities

Full-duplex small cells for next generation heterogeneous cellular networks: a case study of outage and rate coverage analysis.

Full-duplex (FD) technology is currently under consideration for adoption in a range of legacy communications standards due to its attractive features. On the other hand, cellular networks are becoming increasingly heterogeneous as operators deploy a mix of macrocells and small cells. With growing tendency toward network densification, small cells are expected to play a key role in realizing the envisioned capacity objectives of emerging 5G cellular networks. From a practical perspective, small cells provide an ideal platform for deploying FD technology in cellular networks due to its lower transmit power and lower cost for implementation compared with the macrocell counterpart. Motivated by these developments, in this paper, we analyze a two-Tier heterogeneous cellular network, wherein the first tier comprises half-duplex macrobase stations and the second tier consists of the FD small cells. Through a stochastic geometry approach, we characterize and derive the closed-form expressions for the outage probability and the rate coverage. Our analysis explicitly accounts for the spatial density, the self-interference cancellation capabilities, and the interference coordination based on enhanced inter-cell interference coordination techniques. Performance evaluation investigates the impact of different parameters on the outage probability and the rate coverage in various scenarios

Survey of Spectrum Sharing for Inter-Technology Coexistence

Increasing capacity demands in emerging wireless technologies are expected to be met by network densification and spectrum bands open to multiple technologies. These will, in turn, increase the level of interference and also result in more complex inter-technology interactions, which will need to be managed through spectrum sharing mechanisms. Consequently, novel spectrum sharing mechanisms should be designed to allow spectrum access for multiple technologies, while efficiently utilizing the spectrum resources overall. Importantly, it is not trivial to design such efficient mechanisms, not only due to technical aspects, but also due to regulatory and business model constraints. In this survey we address spectrum sharing mechanisms for wireless inter-technology coexistence by means of a technology circle that incorporates in a unified, system-level view the technical and non-technical aspects. We thus systematically explore the spectrum sharing design space consisting of parameters at different layers. Using this framework, we present a literature review on inter-technology coexistence with a focus on wireless technologies with equal spectrum access rights, i.e. (i) primary/primary, (ii) secondary/secondary, and (iii) technologies operating in a spectrum commons. Moreover, we reflect on our literature review to identify possible spectrum sharing design solutions and performance evaluation approaches useful for future coexistence cases. Finally, we discuss spectrum sharing design challenges and suggest future research directions

Spectrum sharing and aggregation for future wireless networks, part II

The papers in this special issue represent the second one in the sequel of three special issues on spectrum sharing and aggregation for future wirelessn networks