No abstract

In a recent paper we presented new measurement results for an angle of arrival based approach to localize UHF RFID transponders in an indoor environment with off-the-shelf IDS R901G RFID reader ICs and UPM Raflatac DogBone RFID transponders. We were able to localize the transponders with a mean accuracy of 0.21 m using three antenna array positions for triangulation in a 3 m x 3 m room. In this paper we present an RSS based algorithm to select a special subset of antenna array positions for the estimation of the transponder position in a measurement setup with five different antenna array positions. With this algorithm a reduction of the mean measurement error by 50% was achieved for the considered test grid compared to the original approach in [1].

No abstract

No abstract

For preliminary performance evaluation of an UHF RFID system, it is important to have a simple and fast simulation environment available. The calculation of the receive signal power at arbitrary positions of a predefined environment should be fast and accurate to find dead zones where tags cannot be read although they are well within the reader's communication range. Changes in the system configuration or the simulated environment must be easy to implement. In this paper we use the simple and fast calculable UHF RFID channel model from [1] and improve it in different aspects to better fit the real indoor multipath signal propagation. A comparison between measurements and simulations shows that our model delivers 1.8 dB better performance in average than the original model, while adding only little complexity and computing time. Using our simulation environment, it is easy and fast to find dead zones for arbitrary system setups.