OPTIMIZED RFID SYSTEM HAVING CHIP-BASED NOVEL SRAP AND DSRAP PROCESSES AND CHIP-LESS FREQUENCY-TIME CODED TAGS FOR INVENTORY MANAGEMENT

摘要

The disclosure describes an RFID system having chip-based novel Simple Random-Access Procedure (SRAP) and Dynamic Simple Random-Access Procedure (DSRAP) tags, and chip-less time and frequency coded tags, for inventory management. The SRAP process contains static (pre-defined) size Frame Structures, and RFID tags compete for network resources by transmitting random preambles to contend for resources to send its Tag-ID to the RFID Reader. The DSRAP process contains dynamic (changing) size Frame Structures and is more efficient than SRAP if the number of tags is lower. The disclosed memory-based variants, save the orthogonal preambles in the tag's memory to reduce the number of transmitted bits and processing necessary to calculate the preambles. To further improve system efficiency and reduce the number of transmitted bits, disclosed memory-based variants may use a pre-defined memory-based modulation (QAM) signal in the memory of the transmitter of the Tags. The disclosure also presents a frequency and time coded chip-less RFID tag system. Each printed chip-less tag has a unique frequency signature, where each chip-less tag's ID is saved in a table in the main memory of the Reader (look-up-table) or in the middleware database. A variable time-delay is added to some chip-less tags to reuse the frequency signatures for a given frame, allowing millions and billions of products to be uniquely identified within a pre-defined time (˜1 sec).