Interference map estimation using spatial interpolation of MDT reports in cognitive radio networks

An LTE-Advanced Radio Access Network (RAN) would be able to activate an additional component carrier in a Licensed Spectrum Access (LSA) channel, allowing the mobile network operator (MNO) to boost capacity and data rates. But such a dynamic spectrum access strategy requires an effective method for estimating the impact of the LTA-Advanced RAN operation on the primary user and minimizing it. LTE-Advanced provides a useful feature, namely the minimization of drive test (MDT) reporting system, wherein the network collects measurement data performed by the user equipment. Each report provides position and signal strength information. In this paper, we compare the performance of some spatial interpolation methods that would be used to reconstruct the interference map of an LTE-Advanced RAN based on the MDT reports. In this way, the MNO can determine if an LSA channel could be used without potential harm to the primary user operation just by checking the estimated interference map. Furthermore, the performance of different interpolation methods for establishment of interference map is analyzed, when the MDT reports containing errors in the values or locations of the reported measurements. Estimation accuracy is also evaluated respect to spatial correlation.