Indoor location algorithm on RFID and its improvement

LANDMARC nearest neighbor algorithm of RFID improves the precision positioning and needs to increase the number of the readers and the reference tags, thereby increasing the system cost. Based on the analysis of the nearest neighbor algorithm, an improved algorithm is proposed. The algorithm puts the three readers on the three vertices of the triangle,and three sides of the triangle is as the base to expand. Reference tags and virtual tags are put in the expansion of triangle area. Through Newton interpolation polynomial, the calculation for signal strength of the virtual tags estimates the target coordinates. Experimental results show that the improved algorithm is less than the original algorithm with a single reader, seven reference tags, the positioning accuracy for 12% increasing.