2010/09/30 by Junwei Zhang, Zhang, Junwei, M. Cenk Gursoy +2
Computer Science · Engineering · Mathematics · #Cognitive Radio Networks and Spectrum Sensing #Cooperative Communication and Network Coding #FOS: Computer and information sciences #Information Theory (cs.IT) #Wireless Communication Security Techniques #cs.IT #math.IT
paper · pdf · doi:10.48550/arxiv.1009.6197
arxiv created 2010/09/30 · openalex publication_date 2010/09/30 · arxiv updated 2010/10/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
In this paper, a cognitive relay channel is considered, and amplify-and-forward (AF) relay beamforming designs in the presence of an eavesdropper and a primary user are studied. Our objective is to optimize the performance of the cognitive relay beamforming system while limiting the interference in the direction of the primary receiver and keeping the transmitted signal secret from the eavesdropper. We show that under both total and individual power constraints, the problem becomes a quasiconvex optimization problem which can be solved by interior point methods. We also propose two sub-optimal null space beamforming schemes which are obtained in a more computationally efficient way.