Analysis of RSS improved RFID estimation

Signal strength (SS) based tag estimation significantly improves the accuracy and speed of RFID tag interrogation. In, SS estimation was applied to a Manchester based RFID system and a formula for the lower bound on number of tags was derived. This paper analytically extends this analysis to a comprehensive list of encoding formats including all those used in commercially available tags. The developed formulas are shown to be based on properties of the line encoding. Our analysis shows that Manchester is the most appropriate encoding scheme for the signal strength estimation method.