A smart collision recovery receiver for RFIDs

In this work, we focus on framed slotted Aloha (FSA) and passive ultra high-frequency radio frequency identification multi-antenna systems with physical layer collision recovery. We modify the tags slightly by adding a so-called ‘postpreamble’ that facilitates channel estimation. Furthermore, we investigate the throughput performance of advanced receiver structures in collision scenarios. More specifically, we analyse the throughput of FSA systems with up to four receive antennas that can recover from a collision of up to eight tags on the physical layer and acknowledge all tags involved in that collision. Due to the higher collision recovery capabilities, the frame sizes can be significantly reduced, and thus, the throughput can be increased. We also derive analytically optimal frame sizes, given that a certain number of collisions can be resolved. We further study the constraints to the throughput due to the structure of our receiver and channel estimation for different collision scenarios. Furthermore, we propose a novel collision recovery method with two phases: first, a successive interference cancellation and, second, a projection of the constellation into the orthogonal subspace of the interference. Additionally, the inventory time, i.e. the number of slots necessary to successfully decode all tags in the reader range, is calculated and compared for different receiver types. A validation of our theoretical predictions is achieved by means of simulations. We show that by our proposed methods, we can realistically achieve more than ten times higher throughput or, equivalently, a reduction of the inventory time by more than 90%.

[1]  George N. Karystinos,et al.  Inventory time reduction in Gen2 with single-antenna separation of FM0 RFID signals , 2011, 2011 IEEE International Conference on RFID-Technologies and Applications.

[2]  George N. Karystinos,et al.  Single-Antenna Coherent Detection of Collided FM0 RFID Signals , 2012, IEEE Transactions on Communications.

[3]  Harish Viswanathan,et al.  Optimal channel training for multiple antenna systems , 2000 .

[4]  F.J. Gonzalez-Castao,et al.  Analysis of DFSA anti-collision protocols in passive RFID environments , 2009, 2009 35th Annual Conference of IEEE Industrial Electronics.

[5]  Paolo Castiglione,et al.  Pseudo-Random ALOHA for Enhanced Collision-Recovery in RFID , 2013, IEEE Communications Letters.

[6]  Anna Scaglione,et al.  Multipacket Reception of Passive UHF RFID Tags: A Communication Theoretic Approach , 2011, IEEE Transactions on Signal Processing.

[7]  Kin K. Leung,et al.  Multiaccess, Mobility and Teletraffic for Wireless Communications , 1999 .

[8]  Robert Langwieser,et al.  RFID reader with multi antenna physical layer collision recovery receivers , 2011, 2011 IEEE International Conference on RFID-Technologies and Applications.

[9]  M. Rupp,et al.  Advanced Collision Recovery Receiver for RFID , 2012, 2012 Fourth International EURASIP Workshop on RFID Technology.

[10]  Byeong Gi Lee,et al.  Enhanced collision arbitration protocol utilizing multiple antennas in RFID systems , 2011, The 17th Asia Pacific Conference on Communications.

[11]  G.D. Durgin,et al.  Gains For RF Tags Using Multiple Antennas , 2008, IEEE Transactions on Antennas and Propagation.

[12]  Robert Langwieser,et al.  RFID Reader Receivers for Physical Layer Collision Recovery , 2010, IEEE Trans. Commun..

[13]  A. Lázaro,et al.  Radio Link Budgets for UHF RFID on Multipath Environments , 2009, IEEE Transactions on Antennas and Propagation.

[14]  Luciano Tarricone,et al.  Increasing performance of SDR-based collision-free RFID systems , 2012, 2012 IEEE/MTT-S International Microwave Symposium Digest.

[15]  Jaideep Srivastava,et al.  Adaptive binary splitting for efficient RFID tag anti-collision , 2006, IEEE Communications Letters.

[16]  Markus Rupp,et al.  Slot-wise maximum likelihood estimation of the tag population size in FSA protocols , 2010, IEEE Transactions on Communications.

[17]  M. Rupp,et al.  Channel estimation in tag collision scenarios , 2012, 2012 IEEE International Conference on RFID (RFID).

[18]  Xiangdong Huang,et al.  An anti-collision algorithm based on smart antenna in RFID system , 2008, 2008 International Conference on Microwave and Millimeter Wave Technology.

[19]  Mary Ann Ingram,et al.  Measurements of small-scale fading and path loss for long range RF tags , 2003 .

[20]  Yinghua Cui System efficiency of collision recover binary tree algorithm in RFID , 2012, 2012 IEEE International Conference on RFID-Technologies and Applications (RFID-TA).

[21]  Markus Rupp,et al.  Single antenna physical layer collision recover receivers for RFID readers , 2010, 2010 IEEE International Conference on Industrial Technology.