1,385 research outputs found
A Nonstochastic Information Theory for Communication and State Estimation
In communications, unknown variables are usually modelled as random
variables, and concepts such as independence, entropy and information are
defined in terms of the underlying probability distributions. In contrast,
control theory often treats uncertainties and disturbances as bounded unknowns
having no statistical structure. The area of networked control combines both
fields, raising the question of whether it is possible to construct meaningful
analogues of stochastic concepts such as independence, Markovness, entropy and
information without assuming a probability space. This paper introduces a
framework for doing so, leading to the construction of a maximin information
functional for nonstochastic variables. It is shown that the largest maximin
information rate through a memoryless, error-prone channel in this framework
coincides with the block-coding zero-error capacity of the channel. Maximin
information is then used to derive tight conditions for uniformly estimating
the state of a linear time-invariant system over such a channel, paralleling
recent results of Matveev and Savkin
Hybrid RFID-Based System Using Active Two-Way Tags
Ultra High Frequency (UHF) Radio Frequency Identification (RFID) is a promising technology that has experienced tremendous growth by revolutionizing a variety of industry sectors and applications, such as automated data management, the tracking of a specified object, highway toll collection, library inventory tracking, multi-level asset tracking, and airport baggage control. For many RFID applications, it is desired to maximize the operating distance or read range.
This thesis proposes a design of an analog front-end architecture and the baseband controller for a Class-4 Active Two-Way (C4-ATW) RFID tag in order to maximize or increase the tracking range by implementing a tag-hopping technique. In tag-hopping, C4-ATW RFID tags power their own communication with other C4-ATW RFID tags and existing passive RFID tag while the reader\u27s functionality remains unchanged.
The simulation results indicate that the C4-ATW RFID tag can detect a minimum incident RF input power of -20 dBm at a 120 Kbps data rate. For -20 dBm input power; the achieved read range between a reader and tag is 36.7 meters at 4 W of reader power and between two tags, the read range is 2.15 meters at 25 mW tag power. Combined, the analog front end and baseband controller consume 50.3 mW of power and the area of the chip, including pads, is 854 µm x 542 µm
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