Journal ArticleDOI
Adaptive Power Loading for OFDM-Based Cognitive Radio Systems with Statistical Interference Constraint
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TLDR
An optimal power allocation algorithm for the orthogonal frequency division multiplexing (OFDM)-based cognitive radio (CR) systems with different statistical interference constraints imposed by different primary users (PUs) is developed and the performance has been investigated.Abstract:
In this letter, we develop an optimal power allocation algorithm for the orthogonal frequency division multiplexing (OFDM)-based cognitive radio (CR) systems with different statistical interference constraints imposed by different primary users (PUs). Given the fact that the interference constraints are met in a statistical manner, the CR transmitter does not require the instantaneous channel quality feedback from the PU receivers. A suboptimal algorithm with reduced complexity has been proposed and the performance has been investigated. Presented numerical results show that with our proposed optimal power allocation algorithm CR user can achieve significantly higher transmission capacity for given statistical interference constraints and a given power budget compared to the classical power allocation algorithms namely, uniform and water-filling power allocation algorithms. The suboptimal algorithm outperforms both water-filling algorithm and uniform power loading algorithm. The proposed suboptimal algorithm give an option of using a low complexity power allocation algorithm where complexity is an issue with a certain amount of transmission rate degradation.read more
Citations
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Journal ArticleDOI
Resource Allocation Techniques in Cooperative Cognitive Radio Networks
TL;DR: This paper discusses the taxonomy of objectives and protocols used in the literature for resource allocation in cooperative CRN, and highlights the use of power control, cooperation types, network configurations and decision types used in cooperativeCRN.
Journal ArticleDOI
Robust Power Control and Beamforming in Cognitive Radio Networks: A Survey
TL;DR: An overview on robust design for power control and beamforming in cognitive radio networks (CRNs) is given, modeling methods for parametric uncertainties are analyzed, various design methodologies are introduced, and robust algorithms that have appeared in the literatures are presented.
Journal ArticleDOI
Subcarrier and Power Allocation for OFDMA-Based Cognitive Radio Systems With Joint Overlay and Underlay Spectrum Access Mechanism
TL;DR: The selected numerical results show that a significant gain in terms of total achievable transmission rate can be obtained over an USAM or an OSAM, and the proposed suboptimal scheme, which has a very low complexity, provides a significant improvement in performance over either underlay or overlay spectrum access mechanism.
Journal ArticleDOI
Relay and Power Allocation Schemes for OFDM-Based Cognitive Radio Systems
TL;DR: The presented numerical results show that the performance of proposed suboptimal schemes is close to the optimal solution of the relay and power allocation problem for OFDM-based cognitive radio (CR) systems with single antennae.
Journal ArticleDOI
Evolution and future trends of research in cognitive radio: a contemporary survey
TL;DR: A comprehensive survey on the evolution of CR research covering aspects such as spectrum sensing, measurements and statistical modeling of spectrum usage, physical layer aspectssuch as waveform and modulation design, multiple access, resource allocation and power control, cognitive learning, adaptation and self-configuration, multihop transmission and routing, and robustness and security in CR networks is provided.
References
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TL;DR: The technical challenges that have to be met when implementing the interesting new technology of spectrum pooling are described, which represents the coexistence of two mobile radio systems within the same frequency range.
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Mutual interference in OFDM-based spectrum pooling systems
TL;DR: A quantitative comparison of both approaches to spectrum pooling aims at enabling public access to these spectral ranges without sacrificing the transmission quality of the actual license owners, and it is obvious that both approaches sacrifice bandwidth of the rental system.