University of Southern Queensland Faculty of Health, Engineering & Sciences School of Mechanical & Electrical Engineering Course Number: ELE2601 Course Name: Telecommunications Principles Internal ? Assessment No: 1 External ? This Assessment carries 200 of the 1000 marks total for this Course. Examiner: Dr John Leis Moderator: Dr Andrew Maxwell Assignment: Radio Waveforms & Modulation Date Given: Week 1 Date Due: Wednesday Week 9 Penalty for Late Submission: Loss of 20% of total marks for this assignment per day late. Assignments are to be typed, not handwritten and scanned. Assignments are to be submitted electronically, using the link on your Study Desk. Marked assignments are also returned to you electronically. You do not need a coversheet for this assignment, since it is submitted electronically. Please use PDF format to submit your assignment. Please use the naming convention LastName-StudentNumber.pdf, where StudentNumber is your 10-digit student number, and LastName is your last (family) name. By submitting this assignment, you agree to the following Student Declaration: I hereby certify that no part of this assignment has been copied from any other student's work or from any other source except where due acknowledgement is made in the assignment. No part of this assignment has been written for me by any other person except where such collaboration has been authorised by the Examiner. Any non USQ copyright material used herein is reproduced under the provision of Section 200(1)(b) of the copyright Amendment Act 1980.Telecommunications Principles Radio Waveforms & Modulation Page 2 Objectives The aims of this assignment are: 1. To be able to analyze telecommunications signals (course objectives 1, 2, 3) 2. To be able to compute quantities pertaining to modulation (course objective 4) Students are expected to communicate their findings and ideas in a clear and logical manner. Submission • Assignments must: { Be typed, not handwritten. { Be submitted electronically via the Study Desk. { Be submitted in PDF format, and less than 4M in size. { Use the file naming format LastName-StudentNumber.pdf. { State your name and student number at the top of the first page. • You must not use any MATLAB \toolbox" functions { that is, any which are not shown as toolbox\matlab in response to the which command. • For each question, submit a written report, detailing your approach and discussing your findings. Your report should include diagrams, figures, source code, waveforms and/or images as appropriate for this assignment. • Late assignments are not normally accepted. If you wish to apply for consideration for late submission, it must be done at least one week prior to the due date in writing or via email. Include documentary evidence of illness (a medical certificate) or additional work commitments (a written confirmation of changed work circumstances from your supervisor). For extension applications for other reasons, please contact the examiner at least 2 weeks in advance of the due date. • Students are reminded of the penalties applying to plagiarism. Copying all or part of an assessment from another student, or from the web, is unacceptable. Plagiarism may result in loss of marks, or other penalties as determined by the Academic Misconduct Policy. Further helpful hints on how to correctly reference (and how to avoid plagiarism) may be found under the link Academic Honesty on the course Study Desk. . . . / 3Telecommunications Principles Radio Waveforms & Modulation Page 3 Marking Marks are awarded as per the marking guidelines at the end of each question. The breakdown of marks will be noted on the PDF file returned to you via the Study Desk. Where an explanation or description is specifically requested, your response will be assessed according to the following: 85-100: High Distinction Excellent grasp of the problem. Explicitly addresses the question, uses knowledge from course and outside. Well-argued choice of method or approach as appropriate to the question. Correct grammar and spelling. Referenced if appropriate. 75-85: Distinction Very good grasp of the problem. Addresses the question using knowledge from course. Well-argued choice of method or approach as appropriate to the question. Correct grammar and spelling, perhaps with very minor errors. Referenced if appropriate. 65-75: Credit Understands the problem. Addresses the question using knowledge from course. Lacks clarity of expression or uses an imprecise argument. Moderate spelling or grammatical errors. Referenced if appropriate. 50-65: Pass Has some understanding of the problem. Addresses the question but not clearly. Some misconceptions about the question. Moderate spelling or grammatical errors. 0-50: Fail Has little or no understanding of the problem. Does not really address the question. Significant misconceptions or total lack of understanding of the question. Poor spelling and/or obvious grammatical errors. Software You may use MATLAB or Excel to complete questions where you are required to plot waveforms or calculate results. You may use any MATLAB or Excel notes or tutorials provided in this course as a starting point. You must not use any MATLAB \toolbox" functions { that is, any which are not shown as toolbox\matlab in response to the which command. Where MATLAB coding or Excel macros are required, show all your code or macro for each question as part of your report. . . . / 4Telecommunications Principles Radio Waveforms & Modulation Page 4 Part I Question 1 | 40 Marks The type of waveform plot that you will use for this question is similar to that shown in Figure 1. The \unknown" waveform is shown, together with a reference sinewave. 0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.1 Time (s) -4 -3 -2 -1 4 3 2 1 0 Amplitude (V) Waveform Unknown Reference Figure 1: Example waveforms { simple sinusoidal waves. Waveform files are given on the course home page under Waveform Parameter Files. This is a zip file containing multiple plots. Use the last digit of your student number to select one of these files, For example, if your student number is 0123456789, use the file WaveParamsAssign9.pdf. Each file contains a reference sinewave, and an unknown wave. Determine the parameters for the unknown waveform, as they relate to a standard waveform x(t) = A sin (!t + ') (1) For each of the 3 parameters, explain how you derived the estimate from the waveform plot. Include a table which gives your derived parameter results. Correct Parameters (A, !, ') 20 Explanation of what you did 20 Total 40 . . . / 5Telecommunications Principles Radio Waveforms & Modulation Page 5 Question 2 | 40 Marks The type of waveform plot that you will use for this question is similar to that shown in Figure 2. It is an amplitude modulated waveform. 0 1 2 3 4 5 6 7 8 9 10 Time (s) -10 -8 -6 -4 -2 8 6 4 2 0 10 Amplitude (V) Observed Waveform Figure 2: Example waveform { amplitude modulation. AM waveform files are given on the course home page under Amplitude Modulation Files. This is a zip file containing multiple plots. Use the last digit of your student number to select one of these files, For example, if your student number is 0123456789, use the file AMAssign9.pdf. Each file contains an unknown amplitude modulated (AM) waveform. Determine the parameters for the unknown waveform, as they relate to the standard definition of AM. The modulation signal m(t) is a simple sinusoid, of the form m(t) = Am sin !mt (2) The AM waveform is then described by xAM(t) = Ac sin !ct + Am sin !mt sin !ct (3) = A c (1 + µ sin !mt) sin !ct (4) where the modulation index is µ = A Am c . Determine the parameters of the modulation m(t), the carrier, and the modulation index. For each of the 5 parameters, explain how you derived the estimate from the waveform plot. Include a table which gives your derived parameter results. Correct Parameters (Am, Ac, !m, !c, µ) 20 Explanation of how you derived the parameters 20 Total 40 . . . / 6Telecommunications Principles Radio Waveforms & Modulation Page 6 Part II Question 3 | 40 Marks From your results in Question 1 (simple sinusoidal waveform), plot your waveform using MATLAB or Excel. Plot the reference waveform for comparison. You may use the samples given on the course home page as starting points. Verify that your waveform plot is correct by comparison with the waveform given. Plot waveform & comment 20 MATLAB code or Excel formula 20 Total 40 Question 4 | 40 Marks From your results in Question 2 (AM waveform), plot your waveform using MATLAB or Excel. You may use the samples given on the course home page as starting points. Verify that your waveform plot is correct by comparison with the waveform given. Plot waveform & comment 20 MATLAB code or Excel formula 20 Total 40 Question 5 | 40 Marks Using your modulated AM waveform, perform the following calculations. First, multiply the AM modulated waveform by a sinusoidal (sine) carrier of amplitude 1 and plot the result. Does this help in recovering the modulating waveform? How? Next, multiply the AM modulated waveform by an co-sinusoidal (cosine) carrier and plot the result. Does this help in recovering the modulating waveform? Why or why not? Does this approach of multiplying the waveform by the carrier give a viable demodulation method? Explain your reasoning. Plot waveforms (sine and cosine multiplied) 10 Demodulation { discussion/explanation 30 Total 40 End of Assignment