Cooperative Spectrum Sensing in Cognitive Radio Networks With Noncoherent Transmission
Simin Bokharaiee, Ha H. Nguyen, Ed Shwedyk
2012
IEEE Transactions on Vehicular Technology
The problem of decision fusion for cooperative spectrum sensing in cognitive radio (CR) networks is studied when fading channels are present between the CRs and the fusion center (FC). The CRs perform spectrum sensing using energy detection and transmit their binary decisions to the FC for a final decision on the absence or presence of the primary user activity. Considering the limited resources in CR networks, which makes it difficult to acquire the instantaneous channel-state information,
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... oherent transmission schemes with on-off keying (OOK) and binary frequency-shift keying (BFSK) are employed to transmit the binary decisions to the FC. For each of the transmission schemes considered, energy-and decoding-based fusion rules are developed first. Then, the detection threshold at the CR nodes and at the FC, the combining weights (in the case of the energybased fusion rule), and the sensing time are optimized to maximize the achievable secondary throughput of the CR network. Simulation results verify the theoretical analysis. It is also shown that the energy-based fusion rule outperforms the decoding-based fusion rule when the signal-to-noise ratios (SNRs) of the reporting channels are low, whereas the opposite is true for high SNRs. For the simpler energy-based fusion rule, BFSK achieves higher secondary throughput than OOK, at the expense of a larger transmission bandwidth. Index Terms-Binary frequency-shift keying (BFSK), cognitive radio (CR), decoding-based fusion, energy-based fusion, likelihood ratio test (LRT), noncoherent transmission, on-off keying (OOK), spectrum sensing. Simin Bokharaiee (M'07) was born in Mashhad, Iran, in 1980. She received the B.Sc. degree in electrical engineering from Sharif University of Technology, Tehran, Iran, and the M.Sc. degree in electrical engineering from Ferdowsi University of Mashhad. Since January 2008, she has been working toward the Ph.D. degree with the Her current research interests include detection and spectrum sensing in cognitive radio networks. Ha H. Nguyen (M'01-SM'05) received the B.Eng. degree in electrical engineering from Hanoi University of Technology, Hanoi, Vietnam, in 1995, the M.Eng.
doi:10.1109/tvt.2012.2197769
fatcat:qi3s2k54vbabxczyamdtruchgi