Detection and False Alarm Probabilities over Non-fading and Fading Environment

Cognitive radio which is a low-cost communication system can choose the available frequencies and waveform so that it can restrict the interference on the unlicensed users on the premise automatically. In cognitive radio networks the spectrum sensing is considered as the key technology. On the contrary it is not only able fill voids in the wireless spectrum but also it can increase the spectral efficiency dramatically. The another issue is that sometimes users can experience deep shadowing or fading effect that time accurate detection factor will be compromised. However, we also allow the CK (cognitive Radio) users to co-operate by sharing their information so that it can detect the primary users (PU) to more accurately. Indeed, the main motive of this project is to investigate performance of Co-operative spectrum sensing scheme by upgrade using energy detection and to promote/n the sensing performance in channels such as AWGN and Rayleigh fading channels. At fusion centre (FC) hard decision is performed which is the combination of (OR rule and AND rule). That is why for this extraordinary performance CR (Cognitive Radio) can be able to make final decision about primary user present or not. Additionally, comparisons among data fusion rules have been investigated also for a vast range of average in SNR (Signal to noise ratio) values. As a result, the performance of this CR is evaluated in terms of the probability of miss detection (Pmd) and the probability of false alarm (Pfa). Moreover, the report is compared between the theoretical value and the simulated result and then it describes the relationship between the signal to noise ratio (SNR) and the detections. At last, the method, energy detection and simulation and result are discussed.