LOW-POWER TWO-WAY WIRELESS COMMUNICATION SYSTEM FOR ELECTRONIC SHELF LABELS

摘要

A two-way low-power communication system for an electronic shelf label system uses a multiplicity of labels (95), each of which has an antenna (15) and a diode (16). Data to be received at the label is Manchester encoded (45) and 100 % AM modulated onto a spread-spectrum RF signal emitted from a broadcast antenna in the store ceiling (13). The label detects the RF energy and a simple comparator (44) followed by a Manchester decoder (54) extracts the digital data stream. The result is a minimization of cost and complexity in the label (95) and an optimal exploitation of the bandwidth given the regulatory framework thereof.