Efficient identification UHF RFID system scheme based on combination of DFSA and OVSF-CDMA

The Radio Frequency IDentification (RFID) tags collision problem has been analyzed in this paper. A novel ultra high frequency (UHF) RFID system scheme, which is based on combination of Dynamic Framed Slotted Aloha (DFSA) and Code Division Multiple Access (CDMA) with Orthogonal Variable Spreading Factor (OVSF) code, was proposed. The proposed scheme has an ability to identify at most in (the length of OVSF code) tags simultaneously in one time slot. The theoretical analysis and computer simulation show that the proposed solution has significant improvement in expected system throughput when compared to classical simplex DFSA system scheme. &copy IEICE 2008.