Energy detection of unknown signals over Rayleigh fading channel for EGC and SSC diversity combining techniques

The problem of spectrum congestion is a big challenge for the researchers now a days. This problem can be solved by cognitive radio. With the help of cognitive radio, the spectrum which is not being used by any licensed user, at a particular time period, can be used by secondary or cognitive radio user, making more efficient spectrum utilization. This is done by spectrum sensing process. Among many methods of spectrum sensing, energy sensing method is used in this paper as this is a less complex method as compared to others. Performance of a cognitive radio system is analysed with the help of ROC (Receiver Operating Characteristics) which is the graph between probability of detection and probability of false alarm. As the probability of detection should be high and probability of false alarm should be low, ROC gives a trade off between the two values. In this paper, simulation and analytical results for probability of detection and probability of false alarm are compared for different parameters in AWGN channel. ROC and probability of detection vs SNR results are compared for EGC and SSC diversity combining techniques in Rayleigh fading channel.