Energy-Efficient Cognitive Transmission With Imperfect Spectrum Sensing

• Published in: IEEE journal on selected areas in communications Vol. 34; no. 5; pp. 1320 - 1335
• Main Authors: Zhang, Lin, Xiao, Ming, Wu, Gang, Li, Shaoqian, Liang, Ying-Chang
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.05.2016; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Algorithms; Channels; Cognitive radio; cognitive transmissions; Complexity theory; Data communication; Detection; Detectors; Energy consumption; energy-efficiency; Fading; imperfect sensing; Mathematical models; Maximization; OFDM; Optimization; Search algorithms; Cognitive radio; energy-efficiency; imperfect sensing; cognitive transmissions
• ISSN: 0733-8716; 1558-0008; 1558-0008
• DOI: 10.1109/JSAC.2016.2520166

We investigate the energy efficiency (EE) in cognitive radio networks, where cognitive users are allowed to access a licensed frequency band opportunistically, provided that the licensed band is vacant. In particular, we study the impact of imperfect spectrum sensing and formulate the average EE maximization problem in fading channels as a joint optimization problem of the spectrum sensing duration and the transmit power of cognitive users. Meanwhile, we consider the constraints of both the collision probability between the primary and cognitive transmissions and the outage probability of cognitive transmissions. However, the joint optimization problem subject to the constraints is complicated and it is computationally hard to obtain the optimal solution. Alternatively, we develop two algorithms, i.e., a linear search algorithm and an iterative-based algorithm, with considerable complexity to solve the problem. Numerical results verify the correctness of both algorithms and show that the proposed algorithms can achieve the performance close to that of the exhaustive search algorithm and outperform the state of arts.