Cooperative and noncooperative spectrum sensing techniques using Welch’s periodogram in cognitive radios

Radio spectrum deployment is growing considerably. With this respect finding unutilized frequency channels for new applications has become much more challenging. The problem can be solved by letting unlicensed systems to dynamically use unexploited licensed bands. This kind of flexible spectrum usage requires telecommunication systems to be equipped by an ability to specify unoccupied parts of radio spectrum. One method to identify temporarily unused parts of radio spectrum is spectrum sensing. In this paper, we focus on spectrum sensing using Welch´s periodogram. In particular, we generalize and apply the theoretical analysis of the energy detection to the Welch´s periodogram. Furthermore, we extend our study to cooperative spectrum sensing. The results indicate that the cooperation between two radios provides the highest cooperation gain.