Spectrum Aggregation in Cognitive Radio Access Networks from Power Control Perspective

Abstract

Spectrum scarcity has motivated researchers and standardization bodies to work towards flexible spectrum usage. One of the solutions, Spectrum Aggregation, as proposed by 3GPP, is a way to increase wireless capacity through providing additional bandwidth to users. This chapter presents the Spectrum Aggregation scenario as it is proposed to be incorporated in LTE-Advanced. Furthermore, the interesting extensions of FP7 SACRA European research project regarding Spectrum Aggregation are described. The business and the functional aspects stemming from the incorporation of this solution in the LTE-Advanced networks are presented in detail. From the functionalities that are the cornerstone of the Spectrum Aggregation, namely spectrum sensing, admission control, and power control, the latter one is studied, which is not thoroughly investigated yet, and the authors present its key features. Moreover, a typical power control algorithm is described and enhanced with learning capabilities and policies in order to meet the requirements of the Spectrum Aggregation scenario; the simulation results highlight the need for power control schemes in Spectrum Aggregation cases.