Simulation study of double threshold energy detection method for cognitive radios

Cognitive Radio is a new paradigm in wireless communication to tackle the problem of spectrum underutilization. One of the important functions of cognitive radio is spectrum sensing. There are many spectrum sensing algorithms available in the literature out of which energy detection is widely used because it is easy to implement and it does not require prior information about PU (Primary User). However, the performance of the conventional energy detector deteriorates in low SNR region. Double threshold CSS (Cooperative Spectrum Sensing) was introduced to increase the reliability of decision but at the cost of some sensing information lost. In this paper, we are discussing a method of double threshold CSS in which each CR (Cognitive Radio) sends local decision or observed energy to the FC (Fusion Center) depending on the region in which the observed energy lies. FC then makes a final decision by combining local decisions and observed energy values. We have developed a simulation model to prove the superiority of the proposed algorithm and it has been observed that the proposed method outperforms the conventional CSS in low SNR region. There is almost a 10% improvement in the cooperative probability of detection at -8 dB SNR at 0.1 probability of false alarm.