EGB342 Assignment 1 (15%)
Released: Friday, 9th August 6:00pm (Week 3)
Due: Sunday 1st September, 11:59pm (Week 6)
Group Assignment - (Group of 3 students)
Hearing about your previous signal analysis expertise, Fraser Island tourism manager Natalie
has commissioned you to do some preliminary analysis for a possible radio station to be con-
structed. This radio station is to be used for emergency communication on the island. It is a
public radio station, so sudden weather events or natural disaster information will be broadcast
on this station. It has been decided to utilise the FM transmission protocol. Fraser Island is
quite small, so distance is not a huge concern, thus FM was chosen over AM. This assignment
will focus on the analogue aspects of FM.
*Reminder* Read the entire document before attempting the questions
Preparation
Remember that these tasks are being conducted so Natalie can assess the viability of the station.
This means that the overall goal is not achieved if she does not understand the information you
provide. Fortunately, Natalie’s tourism degree had a minor in engineering, which introduced
her to basic scientific concepts and logical reasoning. Your task is to bridge the gap between her
knowledge and your findings using clear, well reasoned explanations and appropriate graphical
and mathematical assets. Also assume she does not want to flip between documents, so ensure
all relevant contextual information from the brief is in the final report.
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Part 1: FM Theory
This section will test your theoretical understanding of Frequency Modulation. This will prepare
you for Part 2 and Part 3 of the assignment. Part 1 can be handwritten and scanned, or typed.
Add any MATLAB code you use to A1Training.m. Assign values to the listed variables where
possible. Set Part 1 listed variables that you don’t use to zero.
(a) To test a proposed radio link, a carrier with frequency fc1 is frequency modulated by a
single tone with a frequency fm using a frequency sensitivity factor of kf = 60000. The
frequency and the peak magnitude of the carrier is 450 MHz and 10V respectively and the
frequency and the peak magnitude of the message signal is 15 kHz and 1V respectively.
(b) Find an expression for the modulated signal and compute the maximum frequency devia-
tion, Df1, and the modulation index, beta1,
(c) Determine how many side-bands should be selected to contain 98% of the modulated sig-
nal power. You can use the MATLAB built-in besselj function to calculate the Bessel
coefficients.
(d) Plot the corresponding magnitude spectrum.
(e) Estimate the bandwidth of the modulated signal using a spectral plot and compare that
with the theoretical bandwidth given by Carson’s rule.
(f) If the channel is only being used for the voice communications with a 4 KHz message
bandwidth and a 25 KHz radio bandwidth on a 450 MHz carrier, estimate the maximum
frequency sensitivity factor allowed.
(g) With the help of block diagrams describe the operations of a stereo transmitter and a
receiver of FM radio. Create your own block diagram/s.
(h) Describe ‘Capture effect’ in the context of an FM receiver.
(i) If you are asked to use double side-band full carrier AM modulation for the above trans-
mission, calculate the following,
• Modulation index
• Efficiency of modulation
• Bandwidth required.
• Compare this bandwidth with the bandwidth obtained in part (e) and comment on
the observations.
Part 2: FM Training
This section will prepare you for the final implementation by simulating the process in a familiar
environment. Adherence to the function and variable names that are given is essential.
(a) Download the ”Assignment1.zip” files and unzip all the content into a single working di-
rectory.
(b) Open the file GenerateAssignment1Data.m and carefully read the instructions supplied in
the file. Enter first 7 digits of the student numbers in the specified variables and run the
script. This script only needs to be executed once. Begin working from A1Training.m after
A1Data.mat has been generated.
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(c) The signal that you will be using for testing the FM system is given in the variable msg.
This testing signal is identical to a monitoring signal that will be transmitted over the FM
system. Generate the time vector corresponding to this signal and store it in the variable
t2. Sampling frequency is given in the variable fs. Take care in constructing this correctly.
Using this time vector, plot the signal in the time domain. Identify any important features
of the signal.
(d) Estimate the bandwidth of the given message using the spectrum plot and store it in the
variable BW MSG. Describe how you estimated the bandwidth.
(e) Testing the FM system requires that a suitable carrier frequency be chosen. The nature of
the transmission channel dictates the choice of this frequency.
The channel has been saved into your current working directory in the file channel.p. This
channel behaves as a linear time invariant (LTI) system. It takes one input msg tx and
produces one output msg rx. Think of the output as being a distorted version (channel
induced distortions) of the input signal.
The syntax of using the channel is:
[msg rx] = channel(msg tx);
Determine the frequency response of the channel using the impulse response and identify
suitable frequency band to transmit your message signal. Estimate the bandwidth of the
selected frequency band.
Determine a suitable carrier frequency for this channel and store this value in variable fc2
as a value in Hz. Explain your process and fully justify your answer. Use suitable math-
ematical developments, code, and graphical assets to aid the justification. The response
should be no longer than two pages.
(f) Estimate the maximum frequency sensitivity factor and the corresponding modulation in-
dex beta2 to transmit the given message withing the selected band.
(g) Calculate theoretical bandwidth of the FM signal and peak frequency deviation of the
modulation, Df2. Store this value in BW FM. Present these values in your report and
and state any assumptions made.
(h) Create a MATLAB function fm mod to contain your frequency modulation function. The
function header is to conform to the following syntax:
function [msg tx] = fm mod(msg, fc2, fs, Df2);
Where msg tx is the modulated signal, msg is the signal to be modulated, fc2 is the carrier
frequency (in Hz), fs is the sampling frequency (in Hz), and Df2 is the peak frequency
deviation.
(i) Write the body of the frequency modulation function. Do not use the inbuilt MATLAB
integration function. Employ the MATLAB cumsum function instead.
Remember to include the full function in your report.
(j) You are now at a stage to test your system. Take the baseband signal msg and modulate
this signal with the fm mod function. Store the modulated signal in the variable msg tx.
(k) Plot the modulated signal in the time and frequency domains. Compare these plots with
that of the baseband signal. Examine the differences between the signals, and explain these
differences in relation to theory. Comment on the accuracy of your bandwidth calculation.
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(l) Plot and verify that your signal is within the selected frequency band. Comment on any
out of band radiation observed and discuss measures you can take to remove out-of-band
radiation.
(m) Transmit the modulated signal msg tx through the channel using provided function trans-
mit.p. Store the result in variable msg rx.
(n) Describe the demodulation process of FM signal and show how you can implement FM
demodulation in MATLAB.
(o) Demodulate the signal using the provided function and store the result in msg rc:
[msg rc] = fm demod(msg rx, fc2, fs, Df2);
Note that this demodulation function also decodes an emergency message contained within
the signal.
(p) You have now finished testing the system. If the transmission has been performed success-
fully the monitoring string should consist of a message string concatenated with student
numbers of the group members and FRAS-342x appended to the end.
What was the decoded message?
Ensure the following variables are in the MATLAB work-space after script execution.
Part 1 Part 2
fc1 - carrier frequency msg - message
c1 - carrier fs - sample rate
m1 - message Df2 - Peak frequency deviation
kf1 - frequency sensitivity t2 - time vector
y1 - modulated signal (time) BW FM - theoretical bandwidth
Y1- modulated signal (freq) BW MSG - Message bandwidth
beta1-Modulation index fc2 - carrier frequency
Df1 - Peak frequency deviation msg tx - modulated signal
- msg rx - modulated signal after channel
- msg rc - recovered message
- beta2 - modulation index
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Part 3: Radio-frequency Spectrum Measurements
With your FM knowledge from Parts 1 and 2 of the assignment, examine and explore the radio-
frequency spectrum around you in preparation for your trip to the island. A chart illustrating
how the radio-frequency spectrum is allocated among services in Australia can be found in the
link below. For this task you need to borrow a RTL-SDR USB dongle form the technical sup-
port services counter at S-block level 9. Each group should borrow only one hardware package.
http://www.acma.gov.au/webwr/radcomm/frequency_planning/spectrum_plan/arsp-wc.pdf
Setting up Hardware and Software
Set up your hardware and software using the following steps.
Step 1 Download and install the RTL SDR Radio Support package into your MATLAB in-
stallation. Support package hardware setup can be found at the following link.
http://au.mathworks.com/help/supportpkg/rtlsdrradio/ug/support-package-
hardware-setup.html
Step 2 Once the installation is complete, connect your RTL-SDR USB dongle and run the
following command in MATLAB to confirm the successful installation of hardware and
software.
sdrinfo
(a) Write a MATLAB function titled listen fm to listen to a selected FM radio station using
RTL-SDR.
(b) Use the spectrum analyser.m to scan the spectrum. The syntax of the spectrum sweep.p
function used in the spectrum analyser.m script is as follows.
spectrum sweep(start freq,stop freq,rtlsdr fs, number samples, location)
• start freq - Starting frequency (Lower frequency of the observation window)
• stop frequency - Stop frequency (Higher frequency of the observation window)
• rtlsdr fs - RLT-SDR sampling rate, allowed range is 225-300 kHz and 900-3200 kHz.
• number samples - Number of samples per frame (L = 2n, where n < 18)
(c) Several different spectral bands exist, and are used for different purposes. These include,
1. FM analog radio transmission
2. Digital Audio Broadcasting (DAB)
3. Digital Video Broadcasting (DVB)
4. Mobile Frequencies
5. Queensland Government Wireless Network (GWN)
For each of the listed ranges, scan and plot the frequency spectrum. Also state character-
istics of these transmission and the owners of these frequencies.
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(d) Discuss the effect of the number of samples per frame, L, on the above spectral measure-
ments.
(e) Identify several common radio stations in your current area. Label this on a spectrum plot.
(f) From the information gathered in the previous parts, make an informed decision for a
suitable carrier frequency for Fraser Island emergency communication system. Be sure to
list all the factors that impacted your decision.
(g) Discuss the advantages and disadvantages of using Digital emergency communications.
Reflection (Mandatory)
A reflection is to be written and appended to the end of your report. Include a short discussion
(150 to 200 words) that addresses problems encountered, and things that you would have done
differently. Identify what concepts this assignment has reinforced, and areas where you can
improve. This section is mandatory and the assignment is regarded as incomplete if absent.
Academic Integrity Declaration and Group Dynamics -
Individual (Mandatory)
Each group member must individually complete the ‘Academic Integrity Declaration and Group
Dynamics’ online form using the provided link on Blackboard. Individual marks will be
withheld if this is not completed, or if the declaration is not agreed to. In the group
dynamics portion, allocate the percentage contribution of each group member. If you wish, you
may add additional text and request the teaching team review member contribution. If you
experience issues with group members before the due date, please contact the teaching team
via email. If your issues are in hindsight, please give details here.
Interview (Mandatory if requested)
Interviews will take place (at the discretion of the teaching team) to assess the conceptual
understanding. This will be a casual discussion. These interviews are compulsory and grades
are withheld until they are completed. Marks may be deducted for poor demonstration of
content/assignment knowledge. These interviews will only be for selected groups, and you will
be notified if you need to take part in an interview.
Presentation Standards
This assignment includes elements of written and coding assessment. You are expected to work
as a group. Each group is expected to generate and submit one assignment report and one set
of MATLAB code. Marks are based on how easily and effectively ideas are articulated to the
reader.
The teaching team has put together some things to consider -
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The Report Component
An outstanding report demonstrates knowledge and understanding of the subject area. It
communicates ideas clearly and logically with a combination of visual, mathematical and code
assets. It demonstrates insight about the underlying concepts and their implications within
telecommunications and signal analysis. Verbose responses, or correct information not articu-
lated clearly, will attract deductions.
Remember that you are writing to inform.
Mathematical working shows a logical procedure (or justification) for the final solutions i.e. All
non-trivial steps are included. It can be typed or handwritten but must be legible and easily
followed.
Code snippets used in-text should only contain relevant lines of code and should rarely have
more than five lines in a snippet.
Present the report so that it can be understood without reference to the assignment brief. Any
figures or code referenced within the code should be no more than one page turn away. Avoid
the use of “see appendix” and “refer to .m file”. Document flow and coherency is to be priori-
tised. Reports that are difficult to navigate are marked poorly in this criteria.
Write the report assuming that the reader only knows concepts from 1st year
engineering and does not have access to your .m file/s.
Include a title page that states the unit name, unit code, assignment number, your name(s)
and student number(s). Do not include a table of contents, list of figures, nor a list of
tables. Convert the report to the PDF file format before submission. This ensures document
typesetting is preserved across different computers running different operating systems.
The Code Component
The submitted code needs to be executable (in MATLAB R2018a or later) and without run-
time error. If an error is encountered at execution, your assignment will only be marked until
the error. No error correction will be made to make your code ‘run’. Coding for this assignment
should remain within one (provided) file (unless otherwise explicitly instructed). Only include
a separate .m file if absolutely necessary.
Code should be fully commented to describe intent. Comments should contain enough informa-
tion to understand the process without referring to the report. Quality comments encapsulate
your understanding of the topic.
* You may use the code provided in the weekly tutorials to check your solutions, however you
are expected to generate your own code for your assignment. Submitting supplied .p code as
your own work constitutes academic misconduct and will be considered a run-time error. *
Acknowledgment
spectrum sweep.p was generated using a spectrum sweep code of Desktop SDR (http://www.
desktopsdr.com/).
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Submission Checklist
Submission deadline is on the 1st September, 2019, 11:59 pm. This will be a hard deadline
and late submission penalties will apply. As per QUT policy, late assignments receive 0 marks.
 The report, in PDF format, submitted to Turnitin via the Blackboard link
 A .zip file, submitted directly to QUT Blackboard via the provided link, that contains -
• A1Training.m with student IDs of your team
• Functions that are written as a result of explicit assignment instruction
• Any other MATLAB scripts you have developed
 Submissions have been re-downloaded from submission portals and run as-is to confirm
successful upload.
 Online Academic Integrity declaration (Individual).
Submission FAQ
⇒ You do not need to assign your submission with a special name. Blackboard assigns
unique IDs to all submissions. The submission links are accessible through:
EGB342 19se2 → Assessment → Assessment Item No. 1: Problem Solving
Task → Assignment 1 Submission Links.
⇒ You may submit as many times as you like before the deadline. New submissions overwrite
old submissions. Only the latest submission is recorded and marked. Upload in-progress
versions so there is something to mark if your final submission is late.
⇒ All documents can be reviewed after submission and thus it is your responsibility to verify
that the uploaded documents are not corrupt. Corrupt files are treated as incomplete
assignments.
⇒ Be aware that the electronic time stamp is placed only after all files have uploaded.
Blackboard may experience high traffic or your connection may fail unexpectedly. Begin
your final upload at least an hour before the deadline.
Hardship
If you experience a hardship which affects your ability to complete, or contribute to, this
assignment, please contact the teaching team as soon as it occurs.
QUT also offers counselling services if required.
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EGB342 Assignment 1: Group
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Criteria
Standards
7+ 7 6 5 4 3 2/1
CR1 - 50% weighting
Theoretical understanding
Key Milestones
- Use of FM-related
equations
- Mathematical working
- Sound reasoning for
technical choices
- Modulation methods/
Modulator architecture
- FM placed in a real-world
context
Demonstrates understanding of
the mathematical concepts
underpinning this assignment
beyond the expected ‘7’ level.
Explanations and justifications
are unambiguous, accurate and
logical. Graphical and
mathematical tools are used
masterfully to convey
knowledge of all topics. Uses
appropriate terminology.
Has no conceptual errors, but
one minor technical/numerical
error may exist. Discusses all
required concepts and shows
evidence of further research.
Demonstrates in-depth
understanding of the
fundamental concepts in this
assignment. Explanations and
justifications are generally
clear, accurate and logical.
Graphical and mathematical
tools are used fittingly to
convey knowledge of all topics.
Uses appropriate terminology.
Has no conceptual errors, but
one minor technical/numerical
error may exist. Discusses all
required concepts.
Demonstrates strong
understanding of the
fundamental concepts in this
assignment. Explanations and
justifications are generally
accurate and logical.
Graphical and mathematical
tools are used satisfactorily to
convey knowledge of all
topics. Uses appropriate
terminology.
Has no conceptual errors, but
minor technical/numerical
errors exist. Discusses all
required concepts.
Demonstrates sound
understanding of the
fundamental concepts in this
assignment. Explanations and
justifications are generally
accurate and logical. Graphical
and mathematical tools are
used satisfactorily to convey
knowledge of most topics.
Uses appropriate key
terminology.
One minor conceptual error
and no more than two
technical/numerical errors may
exist. Discusses all key
concepts.
Demonstrates rudimentary
understanding of the
fundamental concepts in this
assignment. Explanations
and justifications are
generally accurate and logical
but are sometimes unclear.
Graphical and mathematical
tools are used adequately to
convey knowledge of most
topics. Uses appropriate key
terminology.
Only minor conceptual,
technical or numerical errors
exist. Discusses most key
concepts.
Conceptual
understanding is
not demonstrated
explicitly
OR
Major conceptual
error
OR
Discussion does
not demonstrate
understanding of
the expected ‘4’
level.
Incorrect
interpretation/s
of underlying
concepts i.e.
Multiple major
conceptual
errors. Does
not recognise
basic errors
when discussing
generated
diagrams.
CR3 - 20% weighting
Effective written
communication
Key Milestones
- Informative
- Easy to read
- Clearly explained core
ideas
- Reflection demonstrates
intended learning
outcomes
Professional format, insightful,
core technical ideas are clearly,
accurately and succinctly
conveyed. The report is very
easy to read, and has been
written to inform. Only
relevant code included in
snippets. Figures demonstrate
intended point excellently.
Referencing is present, and has
been done correctly (IEEE).
Reflection shows all learning
outcomes were reached.
Professional format, core
technical ideas are clearly and
accurately conveyed. The
report is easy to read, and has
been written to inform.
Mostly relevant code included
in snippets. Figures
demonstrate intended point
very well. Reflection shows all
learning outcomes were
reached.
Professional format, technical
ideas are clearly conveyed,
one minor inaccuracy. The
report is informative and easy
to read. Mostly relevant code
included in snippets. Figures
demonstrate intended point
well. Reflection shows most
learning outcomes were
reached.
Report format is adequate but
missing some coherence in its
structure. The report is difficult
to read in one or two sections.
Consistently irrelevant code
included in snippets. Figures
demonstrate intended point
satisfactorily. Reflection shows
some learning outcomes were
reached.
Report format is missing
several critical explanations.
The report is difficult to read
in several parts. Large
amounts of irrelevant code
included. Figures
demonstrate intended points
adequately. Little evidence
of reflective thinking.
Report formatting
was attempted.
Contains little, or
vague, discussion
and lacks
cohesion. Largely a
code and figure
dump. No
evidence of
reflective thinking.
The report has
little or no
structure. No
evidence of
reflective
thinking.
CR2 - 30% weighting
Application using Coding
Key Milestones – For a 7 in this criteria, all milestones must be satisfactorily reached; For a 6, most must be satisfactorily reached, and so on.
 Correct individual-question outputs as per solution-script options
Code appears to give correct outputs if widely-varying solutions are possible
 Code is optimised (i.e. makes use of vectorisation where appropriate)
 Comments are effectively used to describe the code
 No runtime errors
 Uses functions that are within the scope of the assignment
 Code achieves desired output/s on completion
Large sections of code incomplete
OR
Multiple runtime errors
For moderation of overall marks: At the discretion of the teaching team, your group may be selected to attend an interview if the teaching team require clarification about how the group arrived at their solutions, or how individuals
contributed to the overall solution. If selected, you will be notified and given details of the location and time of the interview.
Oral interview Demonstrated knowledge is consistent with submitted report and code. No moderation of marks. Demonstrates knowledge
noticeably below the
standard of the submitted
report and code. Individual
marks may be moderated
down up to 20%.
Demonstrates knowledge significantly
below the standard of the submitted
report and code OR Does not attend
interview. Individual marks may be
moderated down up to 100%.