辅导案例-EGB342

  • May 15, 2020

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 Nataliehas 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 apublic radio station, so sudden weather events or natural disaster information will be broadcaston this station. It has been decided to utilise the FM transmission protocol. Fraser Island isquite small, so distance is not a huge concern, thus FM was chosen over AM. This assignmentwill focus on the analogue aspects of FM.*Reminder* Read the entire document before attempting the questionsPreparationRemember 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 youprovide. Fortunately, Natalie’s tourism degree had a minor in engineering, which introducedher to basic scientific concepts and logical reasoning. Your task is to bridge the gap between herknowledge and your findings using clear, well reasoned explanations and appropriate graphicaland mathematical assets. Also assume she does not want to flip between documents, so ensureall relevant contextual information from the brief is in the final report.1Part 1: FM TheoryThis section will test your theoretical understanding of Frequency Modulation. This will prepareyou 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 wherepossible. 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 asingle tone with a frequency fm using a frequency sensitivity factor of kf = 60000. Thefrequency and the peak magnitude of the carrier is 450 MHz and 10V respectively and thefrequency 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 Besselcoefficients.(d) Plot the corresponding magnitude spectrum.(e) Estimate the bandwidth of the modulated signal using a spectral plot and compare thatwith the theoretical bandwidth given by Carson’s rule.(f) If the channel is only being used for the voice communications with a 4 KHz messagebandwidth and a 25 KHz radio bandwidth on a 450 MHz carrier, estimate the maximumfrequency sensitivity factor allowed.(g) With the help of block diagrams describe the operations of a stereo transmitter and areceiver 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 onthe observations.Part 2: FM TrainingThis section will prepare you for the final implementation by simulating the process in a familiarenvironment. 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 inthe file. Enter first 7 digits of the student numbers in the specified variables and run thescript. This script only needs to be executed once. Begin working from A1Training.m afterA1Data.mat has been generated.2(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 FMsystem. Generate the time vector corresponding to this signal and store it in the variablet2. 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 featuresof the signal.(d) Estimate the bandwidth of the given message using the spectrum plot and store it in thevariable BW MSG. Describe how you estimated the bandwidth.(e) Testing the FM system requires that a suitable carrier frequency be chosen. The nature ofthe transmission channel dictates the choice of this frequency.The channel has been saved into your current working directory in the file channel.p. Thischannel behaves as a linear time invariant (LTI) system. It takes one input msg tx andproduces one output msg rx. Think of the output as being a distorted version (channelinduced 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 identifysuitable frequency band to transmit your message signal. Estimate the bandwidth of theselected frequency band.Determine a suitable carrier frequency for this channel and store this value in variable fc2as 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 responseshould 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 themodulation, Df2. Store this value in BW FM. Present these values in your report andand state any assumptions made.(h) Create a MATLAB function fm mod to contain your frequency modulation function. Thefunction 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 carrierfrequency (in Hz), fs is the sampling frequency (in Hz), and Df2 is the peak frequencydeviation.(i) Write the body of the frequency modulation function. Do not use the inbuilt MATLABintegration 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 modulatethis 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 withthat of the baseband signal. Examine the differences between the signals, and explain thesedifferences in relation to theory. Comment on the accuracy of your bandwidth calculation.3(l) Plot and verify that your signal is within the selected frequency band. Comment on anyout of band radiation observed and discuss measures you can take to remove out-of-bandradiation.(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 FMdemodulation 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 withinthe 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 studentnumbers 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 2fc1 – carrier frequency msg – messagec1 – carrier fs – sample ratem1 – message Df2 – Peak frequency deviationkf1 – frequency sensitivity t2 – time vectory1 – modulated signal (time) BW FM – theoretical bandwidthY1- modulated signal (freq) BW MSG – Message bandwidthbeta1-Modulation index fc2 – carrier frequencyDf1 – Peak frequency deviation msg tx – modulated signal- msg rx – modulated signal after channel- msg rc – recovered message- beta2 – modulation index4Part 3: Radio-frequency Spectrum MeasurementsWith 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 illustratinghow the radio-frequency spectrum is allocated among services in Australia can be found in thelink 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.pdfSetting up Hardware and SoftwareSet 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.htmlStep 2 Once the installation is complete, connect your RTL-SDR USB dongle and run thefollowing command in MATLAB to confirm the successful installation of hardware andsoftware.sdrinfo(a) Write a MATLAB function titled listen fm to listen to a selected FM radio station usingRTL-SDR.(b) Use the spectrum analyser.m to scan the spectrum. The syntax of the spectrum sweep.pfunction 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 transmission2. Digital Audio Broadcasting (DAB)3. Digital Video Broadcasting (DVB)4. Mobile Frequencies5. 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.5(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 asuitable carrier frequency for Fraser Island emergency communication system. Be sure tolist 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 donedifferently. Identify what concepts this assignment has reinforced, and areas where you canimprove. 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 GroupDynamics’ online form using the provided link on Blackboard. Individual marks will bewithheld if this is not completed, or if the declaration is not agreed to. In the groupdynamics portion, allocate the percentage contribution of each group member. If you wish, youmay add additional text and request the teaching team review member contribution. If youexperience issues with group members before the due date, please contact the teaching teamvia 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 conceptualunderstanding. This will be a casual discussion. These interviews are compulsory and gradesare withheld until they are completed. Marks may be deducted for poor demonstration ofcontent/assignment knowledge. These interviews will only be for selected groups, and you willbe notified if you need to take part in an interview.Presentation StandardsThis assignment includes elements of written and coding assessment. You are expected to workas a group. Each group is expected to generate and submit one assignment report and one setof MATLAB code. Marks are based on how easily and effectively ideas are articulated to thereader.The teaching team has put together some things to consider -6The Report ComponentAn outstanding report demonstrates knowledge and understanding of the subject area. Itcommunicates ideas clearly and logically with a combination of visual, mathematical and codeassets. It demonstrates insight about the underlying concepts and their implications withintelecommunications 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. Allnon-trivial steps are included. It can be typed or handwritten but must be legible and easilyfollowed.Code snippets used in-text should only contain relevant lines of code and should rarely havemore than five lines in a snippet.Present the report so that it can be understood without reference to the assignment brief. Anyfigures or code referenced within the code should be no more than one page turn away. Avoidthe 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 yearengineering 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 oftables. Convert the report to the PDF file format before submission. This ensures documenttypesetting is preserved across different computers running different operating systems.The Code ComponentThe 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 untilthe error. No error correction will be made to make your code ‘run’. Coding for this assignmentshould remain within one (provided) file (unless otherwise explicitly instructed). Only includea 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 encapsulateyour understanding of the topic.* You may use the code provided in the weekly tutorials to check your solutions, however youare expected to generate your own code for your assignment. Submitting supplied .p code asyour own work constitutes academic misconduct and will be considered a run-time error. *Acknowledgmentspectrum sweep.p was generated using a spectrum sweep code of Desktop SDR (http://www.desktopsdr.com/).7Submission ChecklistSubmission deadline is on the 1st September, 2019, 11:59 pm. This will be a hard deadlineand 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 confirmsuccessful upload. Online Academic Integrity declaration (Individual).Submission FAQ⇒ You do not need to assign your submission with a special name. Blackboard assignsunique IDs to all submissions. The submission links are accessible through:EGB342 19se2 → Assessment → Assessment Item No. 1: Problem SolvingTask → Assignment 1 Submission Links.⇒ You may submit as many times as you like before the deadline. New submissions overwriteold submissions. Only the latest submission is recorded and marked. Upload in-progressversions 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 verifythat the uploaded documents are not corrupt. Corrupt files are treated as incompleteassignments.⇒ 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. Beginyour final upload at least an hour before the deadline.HardshipIf you experience a hardship which affects your ability to complete, or contribute to, thisassignment, please contact the teaching team as soon as it occurs.QUT also offers counselling services if required.8EGB342 Assignment 1: Group 1 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 coreideas - Reflection demonstratesintended learningoutcomes 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 optionsCode 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 completionLarge 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%.

LATEST POSTS
MOST POPULAR

ezAce多年来为广大留学生提供定制写作、留学文书定制、语法润色以及网课代修等服务,超过200位指导老师为您提供24小时不间断地服务。