2012/04/04 by Amitav Mukherjee, Mukherjee, Amitav, Minyan Pei +3
Computer Science · Engineering · #Advanced MIMO Systems Optimization #Cognitive Radio Networks and Spectrum Sensing #Cooperative Communication and Network Coding #FOS: Computer and information sciences #Information Theory (cs.IT)
paper · pdf · doi:10.48550/arxiv.1204.1096
openalex publication_date 2012/04/04 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
This paper studies a novel underlay MIMO cognitive radio (CR) system, where\nthe instantaneous or statistical channel state information (CSI) of the\ninterfering channels to the primary receivers (PRs) is completely unknown to\nthe CR. For the single underlay receiver scenario, we assume a minimum\ninformation rate must be guaranteed on the CR main channel whose CSI is known\nat the CR transmitter. We first show that low-rank CR interference is\npreferable for improving the throughput of the PRs compared with spreading less\npower over more transmit dimensions. Based on this observation, we then propose\na rank minimization CR transmission strategy assuming a minimum information\nrate must be guaranteed on the CR main channel. We propose a simple solution\nreferred to as frugal waterfilling (FWF) that uses the least amount of power\nrequired to achieve the rate constraint with a minimum-rank transmit covariance\nmatrix. We also present two heuristic approaches that have been used in prior\nwork to transform rank minimization problems into convex optimization problems.\nThe proposed schemes are then generalized to an underlay MIMO CR downlink\nnetwork with multiple receivers. Finally, a theoretical analysis of the\ninterference temperature and leakage rate outage probabilities at the PR is\npresented for Rayleigh fading channels.We demonstrate that the direct FWF\nsolution leads to higher PR throughput even though it has higher interference\n"temperature (IT) compared with the heuristic methods and classic waterfilling,\nwhich calls into question the use of IT as a metric for CR interference.\n