Module Title:Digital Communications
Language of Instruction:English
Credits: 5
NFQ Level:7
Module Delivered In 2 programme(s)
Teaching & Learning Strategies: (a) Teaching will be conducted using lectures, tutorials and practicals. (b) The Institute MLE will be used to evaluate the students understanding of the basic concepts during each section using multiple choice questions. (c) At the end of each section, self-test question sheets will be issued to the students. They will have one week to complete these questions. Any difficulties arising from the self-test question sheets will be addressed during the following tutorial. (d) At various stages of the module students will be directed to certain websites and will have to research certain topics (given exact research criteria). These topics will form the basis of discussion in a tutorial session. (e) The practical sessions will be used to back up the theory.
Module Aim: To provide the student with:an understanding of the various types of noise and their effects on the performance of analogue and digital communications systems; a knowledge of digital modulation techniques; an understanding of how Broadband and N-ISDN is used in Ireland; an introduction to source coding; an overview of how cellular networks operate worldwide.
Learning Outcomes
On successful completion of this module the learner should be able to:
LO1 Describe the various types of noise and their effects on the performance of analogue and digital communications systems.
LO2 Explain the various types of digital modulation techniques.
LO3 Describe how Broadband and N-ISDN is implemented in Ireland.
LO4 Describe source, channel and line coding.
LO5 Explain how cellular networks operate worldwide.
Pre-requisite learning
Module Recommendations

This is prior learning (or a practical skill) that is recommended before enrolment in this module.

No recommendations listed
Incompatible Modules
These are modules which have learning outcomes that are too similar to the learning outcomes of this module.
6465 DIGT H3604 Digital Communications
Co-requisite Modules
No Co-requisite modules listed
Requirements
This is prior learning (or a practical skill) that is mandatory before enrolment in this module is allowed.
Electronic Communications or equivalent
 

Module Content & Assessment

Indicative Content
1. Noise
(i) Describe in broad terms the meaning of noise (EMI) (ii) Contrast analogue and digital communications systems under the headings: effects of noise and bandwidth required (amplifier versus regenerator, frequency spectrum of an analogue signal versus the frequency spectrum of a digital signal).
2. PCM
(i) Draw a block diagram of a PCM system. (ii) Describe the function and operation of each block. (iii) Calculate the channel capacity required, given the maximum input frequency and the number of bits per sample. (iv) Describe bit error noise and quantisation noise, describe how both types of noise can be minimised and any associated costs. (v) Calculate the SNR (signal to quantising noise ratio) for a system with the following inputs: sinusoidal, signal with a gaussian distribution and a signal with a normal distribution. (vi) Describe the need for non-linear quantisation. (vii) Draw the compression and expansion characteristics for a compander.
3. Mulitplexing
(i) Describe Frequency Division Multiplexing (FDM). (ii) Describe Time Division Multiplexing (TDM). (iii) For a FDM system calculate the number of channels available given the bandwidth of the signal, the bandwidth of the medium and the size of the guard band. (iv) For a TDM system calculate the number of channels available given the bandwidth of the signal, the duration of each bit on the line and the number of bits per sample. (v) Describe how the time slots are used in an E1 link.
4. Broadband
(i) Draw a block diagram of the frequency spectrum of ADSL. (ii) Describe the operation of DMT. (iii) Describe the ATU-C Transmitter and Receiver Models. (iv) Describe the structure of ADSL Frames and Channels. (v) Describe the different variants of ADSL, T1.413, G.DMT G.992.1, G.Lite G.992.2, G.DMT.bis G.992.3, G.lite.bis G.992.4, ADSL2+ G.992.5, G.992.5 Annex , Gspan+ Gspan++. (vi) Describe the other DSL types and their uses IDSL, RADSL, SDSL, HDSL, G.SHDSL, VDSL, VDSL2.
5. ISDN
(i) Draw a block diagram of a subscribers premises and indicate the R,S,T.U and V reference points. (ii) Describe the function of a: TE1, TE2, TA and NT. (iii) Describe the structure of BRA. (iv)Describe the structure of PRA. (v) Describe how PRA is used for DDI in Ireland. (vi) Describe how PRA is used for Data Base Indexing. (vii) Describe the following ISDN classification of telecommunications services: bearer services, teleservices and supplementary service. (viii) Describe and contrast: in-band signalling, channel associated signalling and common channel signalling.
6. Line Coding
(i) Describe the characteristics of a good line code. (ii) Describe the following terms: unipolar, polar and bipolar. (iii) Given a digital codeword to be transmitted draw the waveform sent to the line for the following polar codes: NRZ-L, NRZ-I, RZ, Manchester and differential Manchester. (iv) Given a digital codeword to be transmitted draw the waveform sent to the line for the following bipolar codes: AMI, 4B3T, HDB3 and B8ZS. (v) Sketch the spectral density for the line codes mentioned.
7. Digital to Analogue Modulation
(i) Define signalling rate and information rate. (ii) Describe ASK, FSK and PSK. (iii) Contrast QPSK and QDPSK. (iv) Describe QAM. (v) Draw a constellation diagram for each of the modulation schemes mentioned. (vi) Calculate the information rate given the baud rate of the link and the type of modulation employed.
Information
(i) Define the following terms: Bit, Entropy, Information, Information rate. (ii) Calculate the maximum channel capacity available in a M-ary system, given the bandwidth and the value of m. (iii) Calculate the relative entropy and entropy rate given the probability of occurrence of each symbol in a message.
Introduction to Cellular Networks
(i) List the allocated frequency ranges. (ii) Describe the structure of a cellular network. (Cells, BTS, Node-B, MSC, clusters and traffic areas). (iii) Describe the function of a HLR, VLR, EIR, GGSN, SGSN, PDSN. (iv) Describe the process of registration, tracking and hand-off. (v) Describe the functions of Edge and HSDPA (vi) Describe how data calls are processed on 2.5G, 3G and 4G cellular networks.
8. Source coding
(i) Describe the requirement for source coding. (ii) Develop a Shannon-Fano code, given the probability of occurrence of each symbol. (iii) Develop a Huffman code, given the probability of occurrence of each symbol. (iv) Calculate the average code length and coding efficiency for codes developed using the techniques mentioned above. (v) Distinguish between source coding and channel coding.
Assessment Breakdown%
Continuous Assessment10.00%
Practical20.00%
End of Module Formal Examination70.00%
Continuous Assessment
Assessment Type Assessment Description Outcome addressed % of total Assessment Date
Other Class Test. Web based research on a new or emerging technology, The student will be given clear guidelines on what he/she is expected to research and compile a report on. 1,2,3,4,5 10.00 n/a
No Project
Practical
Assessment Type Assessment Description Outcome addressed % of total Assessment Date
Practical/Skills Evaluation Students will complete a set of practical assignments including reports in the laboratory. 2,4 15.00 n/a
Practical/Skills Evaluation Students will complete a practical test in the laboratory 2,4 5.00 n/a
End of Module Formal Examination
Assessment Type Assessment Description Outcome addressed % of total Assessment Date
Formal Exam The written examination will evaluate the extent of the student’s knowledge of the learning outcomes. 1,2,3,4,5 70.00 End-of-Semester

ITCarlow reserves the right to alter the nature and timings of assessment

 

Module Workload

Workload: Full Time
Workload Type Frequency Average Weekly Learner Workload
Lecture Every Week 1.50
Practicals Every Week 1.00
Independent Learning Time Every Week 1.00
Total Hours 3.50
 

Module Delivered In

Programme Code Programme Semester Delivery
CW_EESYS_B Bachelor of Engineering (Honours) in Electronic Systems 5 Mandatory
CW_EEEEN_D Bachelor of Engineering in Electronic Engineering 5 Mandatory