Cooperative multiple access in cognitive radios to enhance QoS for cell edge primary users: asynchronous algorithm and convergence
2016 (English)In: Telecommunications Systems, ISSN 1018-4864, E-ISSN 1572-9451, Vol. 61, no 4, 631-643 p.Article in journal (Refereed) Published
Cognitive radio (CR) systems have been proposed for efficient usage of spare spectrum licensed to primary systems. This leads to the issue of providing as much spectrum to CR users as possible while not degrading the quality of service (QoS) of primary users of the spectrum. This paper proposes a novel cooperation scheme between primary and CR users to guarantee QoS of primary users up to the cell edge while making the licensed spectrum available for opportunistic access by the CR users. We suggest that the primary users at the cell edge, who have poor QoS, should allow secondary users to access their spectrum, while at the same time, the secondary users would help to enhance the primary users QoS using superposition coding on the primary users transmissions. Thus the proposed method can provide a so called “win-win strategy” by benefiting both primary and CR users. The proposed cooperative access scheme in cognitive radios solves efficiently the sum-rate maximization problem on cognitive Gaussian Multiple Access Channels (GMACs) for power allocation of primary systems that cooperates with CR systems in a distributed fashion. We solved the problem using iterative Jacobian method in a distributed manner. A totally asynchronous distributed power allocation for sum-rate maximization on cognitive GMACs is suggested. Numerical results show that the QoS of primary users at the cell edge is improved by the proposed cooperative access scheme.
Place, publisher, year, edition, pages
Springer-Verlag New York, 2016. Vol. 61, no 4, 631-643 p.
Cell edge primary users, Cognitive radio, Distributed power allocation, Non-convex QCQP, Sum-rate maximization, Algorithms, Cells, Cognitive systems, Communication channels (information theory), Cytology, Iterative methods, Quality of service, Radio systems, Asynchronous algorithms, Cooperative multiple access, Distributed Power-Allocation, Gaussian multiple-access channels, Primary Users, Sum-rate maximizations, Super-position coding
Computer and Information Science
IdentifiersURN: urn:nbn:se:kth:diva-176240DOI: 10.1007/s11235-015-0058-xISI: 000371417000002ScopusID: 2-s2.0-84959540807OAI: oai:DiVA.org:kth-176240DiVA: diva2:871499
QC 20151116. QC 201604072015-11-162015-11-022016-04-07Bibliographically approved