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09/18/07 10:20:32 (
moving corteks page
= Cognitive Radio Testbed =
[[Image(http://ossie.wireless.vt.edu/trac/chrome/site/corteks_logo_white.png, align=inline, width=300px, title="CORTEKS logo", alt="Screenshot")]]
Carlos Aguayo, Lizdabel Morales, Kyouwoong Kim, Joseph Gaeddert
Watch a [http://computing.ece.vt.edu/~jgaeddert/vid/CORTEKS_demo_sm.mov demonstration video] (4.0MB, requires [http://www.apple.com/quicktime/ QuickTime]).
[[Image(http://ossie.wireless.vt.edu/trac/chrome/site/corteks_setup.png, width=400px, title="CORTEKS setup", alt="Screenshot")]]
CoRTekS (Cognitive Radio Tektronix System) is a cognitive radio testbed using Tektronix test equipment. The transmitter consists of two arbitrary waveform generators (AWGs), a mixer, a few filters, and an amplifier. The receiver is a real-time spectrum analyzer (RSA) that demodulates and senses the channel for interference. All equipment is connected through GPIB to a PC running OSSIE (TAO) on Windows.
[[Image(http://ossie.wireless.vt.edu/trac/chrome/site/corteks_display_1.png, width=400px, title="CORTEKS display", alt="Screenshot")]]
A neural network-based cognitive engine running on the PC decides which parameters are best for the given channel state. The radio can change modulation type, transmission power, frequency, and bandwidth to avoid interference and optimize three main goals:
* meet QoS (in this case, BER)
* maximize throughput
* minimize transmit power
The neural network allows flexibility in the decision-making process and lets the radio learn how its decisions impact its goals. An arbitrary policy can be set by the user with which the radio must comply. The user can choose the limits on transmit power and available modulation types for four different 2.5MHz bands.
Currently the radio can transmit QPSK, 8PSK, 16-, 32-, and 64-QAM and transmit in the 480-490MHz UHF television band, however in the next phase we hope to incorporate more sophisticated modulation types, channel coding, interference sensing, refined artificial intelligence algorithms, and faster response times.
Supported by [http://www.tektronix.com/ Tektronix], [http://www.etri.re.kr/ ETRI], [http://www.aro.army.mil/ ARO], [http://www.nsf.gov/ NSF], and [http://www.onr.navy.mil/ ONR].
== Next Phase ==
The next phase of the system will include a significantly higher transfer rate from the RSA to the PC using an LVDS card. This will allow more of the processing to be done on the PC (phase-locked loop, pulse synchronization, interference sensing, etc.) instead of the spectrum analyzer, allowing a greater amount of flexibility in the radio.
Visit OSSIE at