A hybird CDMA-IDMA anti-collision protocol for dense RFID system

This paper proposes a novel hybrid CDMA-IDMA collision arbitration protocol for mobile RFID system. The aims of the proposed protocol are: (1) to prevent collisions among mobile readers; and (2) to avoid collisions for active tags. In the proposed protocol, In reader-to-tag downlink communication, we use CDMA technique to identify reader network; in tag-to-reader uplink communication, we use interleaver as the only mean to distinguish the transmitting data from different tags within the same time range and frequency band. We conducted receiver signal detection and analyze time delay and system throughput. The simulation results proved that the proposed CDMA-IDMA -based protocol not only outperforms in system throughput compared to CDMA-based protocol, but improves time delay.