Priority-Based Zero-Forcing in Spectrum Sharing Cognitive Systems

• Published in: IEEE communications letters 2013-02, Vol.17 (2), p.313-316
• Main Authors: Hamdi, K., Hasna, M. O., Ghrayeb, A., Letaief, K. B.
• Format: Article
• Language: English
• Subjects: Applied sciences; Array signal processing; Cognitive radio; Detection, estimation, filtering, equalization, prediction; Exact sciences and technology; Information, signal and communications theory; Interference; Operation, maintenance, reliability; Quality of service; Radiocommunication specific techniques; Radiocommunications; relaying; Resource management; Signal and communications theory; Signal, noise; spectrum sharing; Systems, networks and services of telecommunications; Telecommunications; Telecommunications and information theory; Throughput; Transmission and modulation (techniques and equipments); Vectors; zero-forcing beamforming
• ISSN: 1089-7798; 1558-2558
• DOI: 10.1109/LCOMM.2013.010313.122195

We consider a spectrum sharing scenario between cognitive radio (CR) users and a licensed primary user (PU), in which the PU is not able to successfully transmit data to its destined receiver. The cognitive base station (CBS) in the vicinity of the primary network, offers its help to transmit the primary data. In return, the CR system is able to share the spectrum with the primary system. We formulate an opportunistic spectrum sharing approach that determines the transmit beamforming weights in order to maximize the overall throughput of the CRs while guaranteeing the quality-of-service (QoS) of the PU. By applying algorithms based on zero-forcing beamforming (ZFB) along with optimal power allocation, the proposed approach is able to achieve cognitive and primary systems requirements.