Abstract
The spectrum sensing is an important activity of cognitive radios over fading channels. A proper sensing performance depends upon the fading margin and number of relays within a wireless link. This paper evaluates the sensing performance of energy detector in multihop networks over Nakagami-n fading channels. The decode and forward relays are considered for the analysis because of their best performance characteristics. Further, digital communication is aided by digital relaying techniques to achieve better performance results. The results yield the optimum value of average SNR based on fading margin and number of relays. The results emphasize that multi-branch networks (Co-operation) is an important tool to combat the effect of fading and to improve the detection probability.