Energy Based Spectrum Detection using DPSS for Cognitive Radios

Due to limited spectrum available for use and steady expansion in the field of wireless applications, it has become necessary to organize all the applications in the same available spectrum. To provide a way out to the trouble of inefficient spectrum usage, Cognitive Radios (CR) are considered as a promising solution. A cognitive radio organization has the ability to perform spectrum sensing and transmission modifications by itself. A foremost detector put in for Thomson's Adaptive Multi- Taper Spectrum Estimation (AMTSE) has been discussed here. The detector has been employed for adapting itself to the maximum and minimum values. As a result, the detection threshold adjusts itself according to the environmental changes. The signal after being linearly precoded, is divided into small segments and the Discrete Prolate Spheroidal Sequences (DPSS) are multiplied with it in order to get better and smooth spectrum for detection. In case of the existence of a PU exists, the technique of interference cancellation has been applied for cancelling the interference. Whereas, when the PU is not using the spectrum band, the Secondary User's (SU) transmitter can detect the Channel condition as a result to the channel mutuality, granting the permission to use the free spectrum band by some other user who needs it. An idea to calculate the energy and detecting the availability of spectrum has been proposed, which leads to reduction in False Alarm Rate P(fa) and rise in probability of detection P(d).