A novel two-stage spectrum sensing for cognitive radio system

In this paper, we propose a novel two-stage spectrum sensing for cognitive radio system. The proposed method combines two well-known spectrum sensing techniques such as energy detection (ED) and maximum eigenvalue detection (MED). At first stage, we will use ED to find power average of received signal. The range of power average can separate into two cases: certain and uncertain area using double-threshold scheme. Certain area is the range of power average that ED can absolutely decision about the presence or absence of primary user (PU). For uncertain area, it is the range of power average that ED can´t make decision about the status of PU. At second stage, in uncertain area, we will use MED to detect primary user instead ED. In simulation results, we present the optimum value of double-threshold for the proposed technique and we consider three wireless microphone signal environments. Moreover, we compare the probability of detection between ED, MED and the proposed technique. Our simulation shows that the proposed scheme has better performance than other spectrum sensing techniques.