Location information based interference control for cognitive radio network in TV white spaces

Controlling the interference from secondary users utilizing TV white spaces (TVWS) to protect primary users (PUs) is of vital importance in multicarrier based cognitive radio (CR) systems. Due to the complexity in the real implementation scenarios, regulations relative to TV white spaces may not be fully implemented, and even meeting all the regulatory requirements can´t guarantee that the primary users are not influenced completely. In this paper, we propose a power allocation algorithm based on location information of the secondary users to minimize the aggregate interference to the licensed TV receivers at the border of TV service contour while making the capacity of secondary system reach a certain level. In the meantime, we need to assure that the minimum aggregate interference meets the required interference protection ratios of incumbent users. Since the use of geolocation and database access is mandated by the regulatory authorities, it is quite easy for the white space database (WSDB) to obtain location information of the secondary users and allocate their power accordingly. Numerical simulations are carried out to validate the effectiveness of the proposed interference control algorithm.