2,687 research outputs found
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
Design and Optimal Configuration of Full-Duplex MAC Protocol for Cognitive Radio Networks Considering Self-Interference
In this paper, we propose an adaptive Medium Access Control (MAC) protocol
for full-duplex (FD) cognitive radio networks in which FD secondary users (SUs)
perform channel contention followed by concurrent spectrum sensing and
transmission, and transmission only with maximum power in two different stages
(called the FD sensing and transmission stages, respectively) in each
contention and access cycle. The proposed FD cognitive MAC (FDC-MAC) protocol
does not require synchronization among SUs and it efficiently utilizes the
spectrum and mitigates the self-interference in the FD transceiver. We then
develop a mathematical model to analyze the throughput performance of the
FDC-MAC protocol where both half-duplex (HD) transmission (HDTx) and FD
transmission (FDTx) modes are considered in the transmission stage. Then, we
study the FDC-MAC configuration optimization through adaptively controlling the
spectrum sensing duration and transmit power level in the FD sensing stage
where we prove that there exists optimal sensing time and transmit power to
achieve the maximum throughput and we develop an algorithm to configure the
proposed FDC-MAC protocol. Extensive numerical results are presented to
illustrate the characteristic of the optimal FDC-MAC configuration and the
impacts of protocol parameters and the self-interference cancellation quality
on the throughput performance. Moreover, we demonstrate the significant
throughput gains of the FDC-MAC protocol with respect to existing half-duplex
MAC (HD MAC) and single-stage FD MAC protocols.Comment: To Appear, IEEE Access, 201
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