A Feedback- Soft Sensing-Based Access Scheme for Cognitive Radio Networks

• Published in: IEEE transactions on wireless communications Vol. 12; no. 7; pp. 3226 - 3237
• Main Authors: Arafa, Ahmed M., Seddik, Karim G., Sultan, Ahmed K., ElBatt, Tamer, El-Sherif, Amr A.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.07.2013; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Access methods and protocols, osi model; Applied sciences; ARQ feedback; Automatic repeat request; Channels; Cognitive radio; Delay; Exact sciences and technology; Feedback; Information, signal and communications theory; Markov chains; Mathematical analysis; Maximization; Networks; Queueing analysis; Queueing theory; Queuing theory; Radiocommunication specific techniques; Radiocommunications; Receivers; Sensors; Signal and communications theory; Signal representation. Spectral analysis; Signal, noise; soft sensing; Studies; Systems, networks and services of telecommunications; Telecommunications; Telecommunications and information theory; Teleprocessing networks. Isdn; Teletraffic; Throughput; Wireless sensor networks; Access control; Information rate; Feedback regulation; Teletraffic; Markov chains; Information transmission; Markov chain; Overlay network; cognitive radio; Queueing system; Traffic management; Spectrum analysis; Traffic control; Random access; ARQ feedback; Metric; Delay time; Optimal planning; Signal analysis; Automatic repeat request; Queue; Radio communication; soft sensing; Software radio
• ISSN: 1536-1276; 1558-2248
• DOI: 10.1109/TWC.2013.061413.120851

In this paper, we examine a cognitive spectrum access scheme in which secondary users exploit the primary feedback information. We consider an overlay secondary network employing a random access scheme in which secondary users access the channel by certain access probabilities that are functions of the spectrum sensing metric. In setting our problem, we assume that secondary users can eavesdrop on the primary link's feedback. We study the cognitive radio network from a queuing theory point of view. Access probabilities are determined by solving a secondary throughput maximization problem subject to a constraint on the primary queues' stability. First, we formulate our problem which is found to be non-convex. Yet, we solve it efficiently by exploiting the structure of the secondary throughput equation. Our scheme yields improved results in, both, the secondary user throughput and the primary user packet delay as compared to the scheme where no feedback information is exploited. In addition, it comes very close to the optimal genie-aided scheme in which secondary users act upon the presumed perfect knowledge of the primary users' activity.