Spectrum Sensing Architecture and Use Case Study: Distributed Sensing over Rayleigh Fading Channels

Chen SUN
Ha Nguyen TRAN
Hiroshi HARADA

IEICE TRANSACTIONS on Communications   Vol.E92-B    No.12    pp.3606-3615
Publication Date: 2009/12/01
Online ISSN: 1745-1345
DOI: 10.1587/transcom.E92.B.3606
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (Special Section on Dynamic Spectrum Access)
Category: Spectrum Sensing
spectrum sensing,  cognitive radio,  cooperative sensing,  collaborative sensing,  selective sensing,  energy detection,  Rayleigh fading,  diversity,  

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To realize dynamic spectrum access (DSA), spectrum sensing is performed to detect the presence or absence of primary users (PUs). This paper proposes a sensing architecture. This architecture enables use cases such as DSA with PU detection using a single spectrum sensor and DSA with distributed sensing, such as cooperative sensing, collaborative sensing, and selective sensing. In this paper we focus on distributed sensing. These sensing schemes employ distributed spectrum sensors (DSSs) where each sensor uses energy detection (ED) in Rayleigh fading environment. To theoretically analyze the performance of the three sensing schemes, a closed-form expression for the probability of detection by ED with selective combining (SC) in Rayleigh fading environment is derived. Applying this expression to the PU detection problem, we obtain analytical models of the three sensing schemes. Analysis shows that at 5-dB signal-to-noise ratio (SNR) and with a false alarm rate of 0.004, the probability of detection is increased from 0.02 to 0.3 and 0.4, respectively, by cooperative sensing and collaborative sensing schemes using using three DSSs. Results also show that the selected sensing scheme matches the performance of the collaborative sensing scheme. Moreover, it provides a low false alarm rate.