The evaluation of detection performance for local spectrum sensing and cooperative spectrum sensing is provided under Rayleigh, Rician and Nakagami fading channel.It is probable that the missed detection of PUs (licensees) by CR users cause severely interference while releasing false alarms by the CR users. The spectrum accessibility will definitely impact which in turn reduces the throughput of the CR network. The energy detector execution of spectrum sensing is done under Rayleigh, Rician and Nakagami fading environments. Also it has been found that the improvement of the detection execution is ensured by the cooperative signal detection by using data fusion rules using ROC curve. Moreover, by using a complex distribution the channel behavior can be more closely modeled and gives a description of multipath fading and shadowing. By comparing the entire three signals it shows that Nakagami performs good then rest of the other two channels i.e. Rayleigh and Rician. Rician channel is better than Rayleigh channel.