Hard-Combined Cooperative Spectrum Sensing Using Time-Frequency Method

Abstract

Cognitive radio is the emerging standard for spectrum efficient wireless systems. Heart of cognitive radio is spectrum sensing, which requires the detection of the primary user in worst environmental condition and make the way for the secondary user to use the unused spectrum efficiently. More recently time-frequency based spectrum sensing techniques are examined for simultaneous detection of unused spectrum in time and frequency domain. Time-frequency distribution of received signal is obtained using time-frequency tool to enhance the information preserved in the noisy signal. This paper investigates the cooperative spectrum sensing using modified Wigner-Ville detection, called S-method time-frequency distribution. The paper uses the S-method detector as local spectrum sensing unit and hard-combining at fusion center to make the global decision. Performance of the time-frequency based cooperative sensing is quantified using ROC curve.