Direction and Location Estimation Algorithm with Power Gravity Point for Spectrum Sharing

A direction and location estimation algorithm is proposed in this paper. In spectrum sharing, it is required to estimate the location of existing systems to avoid interference with them. The power gravity point algorithm estimates transmitter locations with simple data such as location and received power of sensors and equations and therefore, it is considered suitable for spectrum sharing to various wireless systems. On the other hand, since the algorithm assumes an isotropic radiation pattern of antenna for the transmitter, it cannot be applied to a transmitter with directivity. To solve this problem, in this paper, sectorial sub-regions centered on the power gravity point are defined. Calculating the power gravity point of all 360degree sub-regions, the angular locus of the power gravity point is obtained. Using the symmetry of the locus, the direction of the transmitter from the initial power gravity point is estimated. Selecting the sub-region of the direction, the transmitter location is estimated as the power gravity point of the sub-region. Simulation results show that the estimation error of the proposed algorithm is smaller than that of conventional power gravity point algorithms.