Spatial smoothing for 2D direction finding with passive RFID tags

This work presents a novel method of using spatial smoothing techniques for finding the azimuth and elevation of correlated signals. The method is the first to solve this problem using the array interpolation technique for a given 2D array. A fast iterative method progressively obtains higher accuracy as it reduces the solution space. Synthetic examples are given which show the algorithm accurately positioning multiple correlated signals. A practical system for locating RFID (Radio Frequency Identification) tags is also described.