Digital, Microwave and Optical Communications

What am I required to do in this assignment?

You are required to complete the exercises that outlined below. There are exercises for each of the three components: Digital, Microwave and Optical Communications. The exercises are also included below for completeness. Each exercise has a number of marks associated with it, and you will need to answer all of the sub question for each component.

Digital communications

Q1 ) Using a diagram, explain the key components of a digital communications system (10 marks)

Q2 a) A communication channel has a frequency spectrum from 0 up to 3.1 KHz. The channel capacity is 28.8 kps. What is the number of symbol states that the channel supports? (10 marks)

Q2 b) What are the three different ways of modulating a signal when only one degree of freedom is modulated

(10 marks)

Submission Deadline Marks and Feedback

Before 10am on:

25/09/2020

20 working days after deadline (L4, 5 and 7) 15 working days after deadline (L6) 10 working days after deadline (block delivery)

Unit title & code Digital, Microwave and Optical Communications (CIS117-6)

Assignment number and title One – Digital, Microwave and Optical Communications

Assessment type Portfolio

Weighting of assessment 100%

Unit learning outcomes 1. Demonstrate a systematic understanding of the fundamental underpinning scientific principles of digital, microwave and optical communications and the corresponding system components.

2. Critically analyse and assess digital, microwave and optical communication technologies, techniques, models and system design and performance

2

Q3) A discrete memoryless source has an alphabet of eight letters {a,b,c,d,e,f,g,h} with respective with probabilities {0.25, 0.20, 0.15, 0.12, 0.10, 0.08, 0.05, 0.05}.

a) Using a Huffman encoding. Determine binary code for the source output and explain the codewords for each character in the alphabet (10 marks)

b) Determine the average length of the codeword (5 marks)

c) Determine the Huffman code efficiency (5 marks)

Q4) Design a Shannon-Fano code and sketch the corresponding coding tree where the alphabet is {a,b,c,d,e,f} with corresponding probabilities {0.5, 0.1, 0.05, 0.05, 0.25, 0.25} (10 marks)

Microwave communications

Q1) Antennas play a vital role in the performance of wireless communications systems. Microstrip patch

antennas are very widely used in wireless applications due to their inherent features of simple design,

low complexity, ease of fabrication and low cost to meet the design requirements.

The objective of this assignment is the design of a microstrip patch antenna for a practical Wireless

Local Area Network (WLAN) application operating at ISM band in the range of 2.45 GHz. The antenna

is excited using a microstrip transmission line.

a) The important dimensions that need to be optimised include length and width of the ground plane,

patch and feed, and width and length of the two matching cuts on each side of the feed.

1. You need to design an antenna that needs to be matched such that the resonance frequency

is:

fr = 2.45GHz + (last 3 digits of your student ID / 2) Mhz

For example, if your student ID number is 1322300 then the antenna working frequency should

be as follows:

(300)

f r = 2.45GHz + (300/2)MHz

= 2.45GHz +150MHz = 2.6GHz

(20 marks)

3

Optical communications

You have to design a Radio-over-Fibre System for a two storey hospital building that has 10

rooms per floor. The communication link is to be used for a wide variety of functions including

locating physicians, requesting test results, checking patient records of patients and calling for

mobile test data.

a) justify your selection of all the components and show a block diagram of your designed system. All assumptions must be defined.

(10 marks)

b) The performance of the system must be analysed to show that the link budget of the designed system meets the requirements.

(10 marks)

c) Using Optiwave implement the system and show its performance.

(15 marks)

d) Compare the performance of the designed system with simulation results.

(5 marks)

e) What is the maximum number of channels that your system can accommodate? (10 marks)

Supplement your answer by demonstrating a solution in Optiwave.

Is there a size limit?

Yes, the overall report should not exceed 5000 words

What do I need to do to pass? (Threshold Expectations from UIF)

1. Select appropriate solutions from candidates when designing key system components

2. Analyse and evaluate the feasibility of your optical link prototype using suitable methods.

3. Design an optical link using appropriate software tools

4. Analyse and critically evaluate the feasibility of your prototype using suitable methods

5. Effectively and professionally present ideas and solutions

How do I produce high quality work that merits a good grade?

You need to demonstrate clear knowledge and understanding of the three communication system types, as well as providing evidence of analysis and justification of the approaches you have chosen. You must clearly explain the choices you have made and back these up using appropriate theory.

How does assignment relate to what we are doing in scheduled sessions?

4

The assignment builds upon the theory presented in class and helps you to put the theory into practice using appropriate examples and measurements.

How will my assignment be marked?

Your assignment be marked according to the threshold expectations and the criteria on the following page.

You can use them to evaluate your own work and estimate your grade before you submit.

Pass – 40-59% Commendation – 60-69% Distinction – 70%+

1

Select appropriate solutions from candidates when designing key system

Explain and justify the solutions you have made clearly articulating the benefits

Critically evaluate the design choices you have made and clearly explain why you have chosen your approach

2

Analyse and evaluate the feasibility of your optical link prototype using suitable methods.

Critique you chosen design and clearly identify improvements on the basis of the analysis undertaken

Critically evaluate the appropriateness of your chosen system and demonstrate its effectiveness compared to other designs

3

Design an optical link using appropriate software tools

Evaluate the effectiveness of your chosen design making use of appropriate data for the analysis

Compare and contrast your chosen design clearly evaluating effectiveness and making suggestions for future improvements,

4

Analyse and critically evaluate the feasibility of your prototype using suitable methods

Compare and contrast your chosen prototype making suggestions for improvements

Propose how your prototype compares to commercially available solutions.

5.

Effectively and professionally present ideas and solutions

Provide a professional quality set of solutions with clear justifcations and rationale.

Outstanding quality report with professional presentation, high quality outputs and very well explained conclusions