A technique for simultaneous multiple tag identification

Abstract

We present for the first time ever, a technique for simultaneously decoding multiple tag responses (i.e., a collision). Additionally the technique provides a considerable degree of robustness and alleviates the problem of missed tags. A theoretical discussion of the underlying principle is done. We provide simulation results when this technique is used specifically for the EPC Gen 2 protocol; the resultant increase in identification rate is 20% when two tag signals are simultaneously decoded and 30% when three tag signals are simultaneously decoded. Experimental results presented show that the extracted individual tag signals (when there is a collision of two or more tag responses) are virtually identical to the single tag signal. We believe that the signal extraction technique discussed here will eventually be a standard feature of all base stations.