METHOD FOR ENCODING CONTACTLESS COMMUNICATION DATA FROM A TRANSPONDER TO A READER VIA CHARGE MODULATION, IN THE FORM OF A SET OF PATTERNS AND DEVICE FOR IMPLEMENTING SAME

摘要

The invention relates to a method for encoding contactless communication data from a transponder to a reader via charge modulation, in the form of a set of modulation patterns, each modulation pattern being a series of charge levels of a predefined length used for physical encoding, having a duration of n carrier periods (Tc), including a series of at least two charge levels, having a minimum pulse width (w) corresponding to the shortest duration of a single charge level in the pattern, and having a retromodulation rate (t) corresponding to the ratio between the retromodulation time and the duration of a pattern, characterized in that the number (k) of patterns is greater than four, the minimum pulse widths (w) of at least two patterns are different, and the retromodulation rates (t) of at least two patterns are different. The invention also relates to a device for implementing the method.