Robust detectors for cognitive radio system

Increasing demand for wireless technology overburdens the existing frequency spectrum due to the licensed spectrum management. On the other hand, field studies indicate that the spectrum is often underutilized. This leads to a need to reallocate the spectrum dynamically so that the unlicensed users could access the spectrum not required by the primary users. Dynamic spectrum access can be achieved by cognitive radio technology which in turn requires detection of primary user signals at the secondary user locations. In this paper, we investigate the detection of primary user signals in the environment with impulsive noise. We propose proper robust detectors to replace several popular detection schemes that have been developed for the Gaussian noise case. The basis of our development is modelling the noise as consisting of two components, one of them being Gaussian, which has proven itself as a good model for thermal noise, and the other being uniform, which appears with certain probability and models the impulsive noise. In this paper, several detectors arising from this model are proposed and analysed.