Improved Double Threshold Energy Detection in Cognitive Radio Networks

Cognitive radio is an exciting emerging technology that has the potential of dealing with the stringent requirement and scarcity of the radio spectrum. Such new and transforming technology represents a paradigm shift in the design of wireless systems, as it will allow the efficient utilization of the radio spectrum. One of the most crucial challenges for cognitive radio systems is to identify the presence of primary (licensed) users over a wide range of spectrum specific geographic location and at a particular time. To enhance the reliability of detecting primary users in case of hidden terminal problem, we consider cooperative spectrum sensing in cognitive radio systems. Based on conventional single-threshold energy detection algorithm, we discuss about double-threshold version of Energy detector in cognitive radio system, and then, we analyse the detection probability, false alarm probability, probability of miss detection and their relationships. Further, we use two more parameters for performance evaluation: the probability of collision between the cognitive user and the primary user, and the probability of spectrum unavailable spectrum for the cognitive user. Comparing to the single, double-threshold energy detection algorithm, simulation results show that the double-threshold energy detection algorithm can make a lower collision probability between the primary user and the cognitive user, despite a little increasing of the spectrum unavailable probability. Finally by proposed Improved Double threshold Energy detector, by which reduction in the probability of detection is less reduced