Wireless Communications: Principles and Practice
Wireless Communications: Principles and Practice
MACA-P: A MAC for Concurrent Transmissions in Multi-Hop Wireless Networks
PERCOM '03 Proceedings of the First IEEE International Conference on Pervasive Computing and Communications
Opportunistic spectral usage: bounds and a multi-band CSMA/CA protocol
IEEE/ACM Transactions on Networking (TON)
MAC Protocol for Opportunistic Cognitive Radio Networks with Soft Guarantees
IEEE Transactions on Mobile Computing
Channel access protocols for multihop opportunistic networks: challenges and recent developments
IEEE Network: The Magazine of Global Internetworking - Special issue title on networking over multi-hop cognitive networks
Cooperative adaptive spectrum sharing in cognitive radio networks
IEEE/ACM Transactions on Networking (TON)
Some complexity results about packet radio networks (Corresp.)
IEEE Transactions on Information Theory
Cognitive radio: brain-empowered wireless communications
IEEE Journal on Selected Areas in Communications
IEEE Journal on Selected Areas in Communications
HC-MAC: A Hardware-Constrained Cognitive MAC for Efficient Spectrum Management
IEEE Journal on Selected Areas in Communications
Opportunistic medium access control for maximizing packet delivery rate in dynamic access networks
Journal of Network and Computer Applications
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Cognitive radio (CR) is a revolutionary technology in wireless communications that enhances spectrum utilization by allowing opportunistic and dynamic spectrum access. One of the key challenges in this domain is how CR users cooperate to dynamically access the available spectrum opportunities in order to maximize the overall perceived throughput. In this paper, we consider the coordinated spectrum access problem in a multi-user single-transceiver CR network (CRN), where each CR user is equipped with only one half-duplex transceiver. We first formulate the dynamic spectrum access as a rate/power control and channel assignment optimization problem. Our objective is to maximize the sum-rate achieved by all contending CR users over all available spectrum opportunities under interference and hardware constraints. We first show that this problem can be formulated as a mixed integer nonlinear programming (MINLP) problem that is NP-hard, in general. By exploiting the fact that actual communication systems have a finite number of available channels, each with a given maximum transmission power, we transfer this MINLP into a binary linear programming problem (BLP). Due to its integrality nature, this BLP is expected to be NP-hard. However, we show that its constraint matrix satisfies the total unimodularity property, and hence our problem can be optimally solved in polynomial time using linear programming (LP). To execute the optimal assignment in a distributed manner, we then present a distributed CSMA/CA-based random access mechanism for CRNs. We compare the performance of our proposed mechanism with reference CSMA/CA channel access mechanisms designed for CRNs. Simulation results show that our proposed mechanism significantly improves the overall network throughput and preserves fairness.