Secondary user access based on stochastic link estimation in cognitive radio with fibre-connected distributed antennas

• Published in: IET communications Vol. 7; no. 8; pp. 731 - 737
• Main Authors: Ge, Wendong, Ji, Hong, Li, Xi, Leung, Victor C.M
• Format: Journal Article
• Language: English
• Published: Stevenage The Institution of Engineering and Technology 01.05.2013; John Wiley & Sons, Inc
• Subjects: Access control; antenna selection; Antennas; Architecture; Cognitive radio; fibre‐connected distributed antenna; first order relaxation; IEEE 802.22 wireless regional area networks; IEEE standards; knapsack problems; Links; multiantenna transmission technique; Plutonium; primal‐dual index heuristic algorithm; radio links; Random errors; restless bandit problem; SASK problem; second order cone programming problem; secondary user; secondary user access; stochastic knapsack problem; stochastic link estimation; stochastic processes; Stochasticity; SU access problem; transmission power; wireless transmission distance; WRAN; radio links; WRAN; transmission power; fibre-connected distributed antenna; second order cone programming problem; stochastic link estimation; primal-dual index heuristic algorithm; secondary user access; antennas; IEEE 802.22 wireless regional area networks; stochastic knapsack problem; antenna selection; knapsack problems; wireless transmission distance; restless bandit problem; multiantenna transmission technique; secondary user; cognitive radio; first order relaxation; access control; IEEE standards; stochastic processes; SASK problem; SU access problem
• ISSN: 1751-8628; 1751-8636
• DOI: 10.1049/iet-com.2012.0627

In this study, the authors consider the application of a system architecture called cognitive radio (CR) with fibre-connected distributed antennas in IEEE 802.22 wireless regional area networks (WRANs) as it could bring the benefits of much shorter wireless transmission distances, lower transmission power and the possibility of utilising multi-antenna transmission techniques. In this architecture, the authors study the secondary user (SU) access problem in uplink, where the SU to primary user (PU) link estimation is subject to random errors because PU could not assist link estimation of SU. This SU access problem is divided into two parts: antenna selection and access control. Thus, first antenna selection problem is modelled as a restless bandit problem, which is solved by the primal-dual index heuristic algorithm based on first order relaxation. In addition, the access control problem is modelled as a stochastic knapsack (SASK) problem with random weight, and then relaxed to be a deterministic second order cone programming problem. With the deduced upper bound, the access control problem is solved by the branch and bound algorithm, which yields the SU access based on SASK scheme. Simulation results illustrate the significant performance improvement of SASK scheme, compared with existing SU access methods.