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Welcome to the page of my favorite research topic: communication. I like this field very much because I am amazed by the power of communication. In my library, most of the books are communication textbooks. Communication is not only my favorite topic, but also the goal of my life.
So far, I participate two projects in communication field. The first one is building a communication systems for nano-satellite and the second one is a narrow band receiver for bird tracking system.
Satellite Communication Systems
From the summer of 2003 till the end of the year , I participated in the nano-satellite project of University of Illinois at Urbana-Champaign. The goal of this project is to develop a low-cost nano-satellite for observing the environment in the atmosphere.
The satellite will be placed on the low earth orbit. It will operate in the Amateur Radio band (440 MHz ~ 460MHz). It employs two communication schemes. It uses Audio Frequency Shift Keying (AFSK) to modulate the binary signal to digital signal; and it uses Frequency Modulation (FM) to modulate the digital signal to RF level.
Here is a picture of the satellite:
This satellite (ION) is scheduled to be launched on July of 2005
A presentation slide is available:
Satellite_Communication_Systems.pdf (Adobe Acrobat PDF, 911 KB)
If you want have any question, please send me an email at:
research@derrickcheng.com
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Sensitive Narrow band RF receiver
In the summer of 2004, I participated to build a sensitive narrow band RF receiver for bird tracking. This project is supported by Illinois Natural Survey of University of Illinois.
The receiver system is based on the idea of superheterodyne receiver. It receives the RF signal from the air, which is a CW signal (~300 MHz) sent from the bird. After down converting the signal in the audio level, the receiver demodulates the signal into binary level. Since the received signal is very weak (~ -150dbm), the receiver should be able to detect very weak signal and demodulate it correctly.
If you want have any question, please send me an email at:
research@derrickcheng.com
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