Adaptive Threshold Based Energy Detection over Rayleigh Fading Channel

Spectrum sensing is one of the most important affair in the implementation of cognitive radio networks. Energy detection is the widely used spectrum sensing algorithm due to its ease of implementation and non-requirement of any prior information about primary users. However, performance of conventional energy detection scheme deteriorates in the fading environment. Performance of the detector also declines because of the inappropriate setting of decision threshold. In this context, here an adaptive threshold based energy detection scheme is proposed to find the optimal value of threshold for energy detection method over Rayleigh fading channel. A closed-form expression for average probability of detection over Rayleigh channel is derived and thereafter optimal value of threshold is found by Golden section search algorithm. Results demonstrates that proposed scheme performs better than conventional fixed threshold energy detection schemes. For example, our proposal yields a 34% decline in the probability of error at ??25 dB SNR in Rayleigh fading environment.