8th International Conference on Cognitive Radio Oriented Wireless Networks

Research Article

Suppressing RF Front-End Nonlinearities in Wideband Spectrum Sensing

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  • @INPROCEEDINGS{10.4108/icst.crowncom.2013.252105,
        author={Eric Rebeiz and Ali Shahed hagh ghadam and Mikko Valkama and Danijela Cabric},
        title={Suppressing RF Front-End Nonlinearities in Wideband Spectrum Sensing},
        proceedings={8th International Conference on Cognitive Radio Oriented Wireless Networks},
        publisher={ICST},
        proceedings_a={CROWNCOM},
        year={2013},
        month={11},
        keywords={spectrum sensing rf nonlinearities energy detection cyclostationary detection},
        doi={10.4108/icst.crowncom.2013.252105}
    }
    
  • Eric Rebeiz
    Ali Shahed hagh ghadam
    Mikko Valkama
    Danijela Cabric
    Year: 2013
    Suppressing RF Front-End Nonlinearities in Wideband Spectrum Sensing
    CROWNCOM
    IEEE
    DOI: 10.4108/icst.crowncom.2013.252105
Eric Rebeiz1,*, Ali Shahed hagh ghadam2, Mikko Valkama2, Danijela Cabric1
  • 1: University of California Los Angeles, CA, USA
  • 2: Tampere University of Technology, Finland
*Contact email: rebeiz@ee.ucla.edu

Abstract

As a result of wideband analog front-end, wideband spectrum sensing techniques are prone to suffer from RF nonlinearities. Intermodulation products due to strong subbands or carriers stemming from low noise amplifier nonlinearities, can easily degrade the spectrum sensing performance by causing false alarms and degrading the detection probability. We analyze the effects of third-order nonlinearities on both energy detectors and cyclostationary detectors under front-end nonlinearities.We show that the presence of strong blockers in the wideband channel can substantially degrade the sensing performance of both detectors, and energy detectors loose their advantage over cyclostationary detectors. Then, we propose an adaptive interference cancellation algorithm to compensate for the effect of the blockers at any subband of interest. The obtained results also show that when compensation is enabled, cyclostationary detector is more robust to moderate blocker signal levels than the corresponding energy detector.