EE283 Project 1
64-QAM Communications System Design and Characterization
A simple 64-QAM communications system is built and characterized with a
mathematical simulation tool.
Tools:
You can use any tools that you prefer as long as those are general one while MATLAB is
recommended for accessibility. Any scripts or executables should be supported by ECE.
Modular coding and proper commenting are required for documentation, debugging, and
grading. You can use toolbox such as signal processing but not communication.
Things to submit:
1. Documentation: An electronic copy of project documentation (pdf or ps) to
dkim@ee.duke.edu. Embed all the fonts in the file. Follow the IEEE journal format
(http://www.ieee.org). One section of the document should provide the name of the
scripts to execute to obtain the plots in the document.
2. Compressed and 'tar'ed (MATLAB) scripts. The filename should be
“lastname_firstname.tar.gz” or “lastname_firstname.tar.Z”. All the scripts should be in
“lastname_firstname” directory. The plots in the documents should be same as the script
execution results. Script execution must be one-step, i.e., 'filename'+'enter'. The grader
will not debug.
Deadline:
9/24 (Fri) 11:00pm, time marked by the recipient server (ee.duke.edu). There would be a
penalty for late submission (-20% per a day).
Assignments:
1. Data Source (0)
Propose a data source that you will use for your communication system. Discuss the
randomness of data.
2. 64-QAM Memoryless Channel Coder (25)
Design a channel coder with a code rate 1. The designed data source feeds the channel
coder. The coder outputs are 64-QAM in-phase and quadrature-phase data. For example,
with 6-bits taken from data source, an in-phase and a quadrature-phase amplitudes are
produced.
3. QAM Base Band Modulation (25)
Design a QAM modulator. Modulator inputs are the output of 64-QAM channel coder
and the modulation frequency, etc. The output is a modulated QAM waveform. Show
unit in-phase, unit quadrature-phase, and random data waveforms in a fine time
resolution (for readability).
4. Channel Modeling (0)
Design a channel module that adds Gaussian noise to the modulated data with a given
noise intensity. Show a 64-QAM eye diagram.
5. QAM Base Band Demodulation (25)
Design a QAM demodulator. Assume that full phase information is given and the phase
is locked. The demodulator outputs are in-phase and quadrature-phase amplitudes. Show
a demodulated 64-QAM constellation with noise.
6. 64-QAM Channel Decoder (25)
Design a QAM decoder that performs the inverse of the designed 64-QAM channel
coder.
7. BER Measurements (0)
Design a module calculates bit-error-rate with the original data source and the decoded
data stream. Discuss how many measurements are required to get 95% or 99%
confidence. Make a plot of BER vs SNR. All the numbers, such as signal power and
noise power, must be obtained from simulation.
8. Bandwidth Efficiency (0)
Calculate the bandwidth efficiency with a given BER. All the numbers, such as
bandwidth must be obtained from simulation. Discuss the definition of bandwidth of your
baseband waveform.
9. Optional
a) Compare random data to non random data in your link.
b) Experiment with the symbols length T < 1/(2**fc) (wave forms only part of a period
of the sine wave).
c) Experiment with filtering the output of the channel module. A filter with bandwidth
around fc may improve SNR.