Publications in Scientific Journals:

J. Kaitovic, R. Langwieser, M. Rupp:
"A smart collision recovery receiver for RFIDs";
EURASIP Journal on Embedded Systems, 7 (2013), 1 - 19.

English abstract:
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%.

RFID, Collision recovery

"Official" electronic version of the publication (accessed through its Digital Object Identifier - DOI)

Created from the Publication Database of the Vienna University of Technology.