Interference characteristics in power-controlled cognitive radio networks

Dynamic spectrum access using cognitive radios has been proposed as an approach to meet the increasing demand for radio spectrum. Under this novel access paradigm unlicensed cognitive radios are allowed to utilize the white spaces across licensed spectrum on a non-interfering basis. Realization of this concept therefore requires a model translating the regulatory constraint on aggregate interference to system design parameters. Thus far, a few models of aggregate interference have been proposed however, these mainly examine the distribution of interference without explicitly modelling transmit power control. In this paper a statistical model of interference aggregation in power-controlled cognitive radio networks is developed. In particular, distribution of the aggregate interference is characterized in terms of parameters such as density of cognitive radios and access points as well as the underlying propagation environment. The model is further extended to account for the effect of correlated shadowing on the distribution of aggregate interference.