Pulse-Code -Modulation - Coding and Information Theory - Old Exam Paper, Exams of Information Technology

Download Pulse-Code -Modulation - Coding and Information Theory - Old Exam Paper and more Exams Information Technology in PDF only on Docsity! Page 1 of 4 CORK INSTITUTE OF TECHNOLOGY INSTITIÚID TEICNEOLAÍOCHTA CHORCAÍ Semester 1 Examinations 2010/11 Module Title: Coding and Information Theory Module Code: CTEC 8001 School: Mathematics and Computing Programme Title: Bachelor of Science (Honours) in Software Development and Computer Networking – Year 3 Programme Code: KDNET_8_Y3 External Examiner(s): Mr. A. O’Leary Internal Examiner(s): Dr. Oliver Gough Instructions: Answer four questions Duration: 2 Hours Sitting: Winter 2010 Requirements for this examination: Note to Candidates: Please check the Programme Title and the Module Title to ensure that you have received the correct examination paper. If in doubt please contact an Invigilator. Page 2 of 4 Q1. (a) A PC generates data at a rate of 28.8 kbps. The data or bit stream is then encoded to form symbols each containing 256 levels prior to transmission. What is the baud rate on the transmission line and determine the minimum bandwidth required for the transmission line. (8 marks) (b) Explain the operation of a Pulse-Code -Modulation (PCM) system. Discuss the advantages and disadvantages of such a system. (7 marks) (c) An 8-bit PCM system is employed in a telephone network having an analogue bandwidth of 4000Hz. Determine the sampling rate, the bit rate and the required bandwidth. (5 marks) (d) Explain why the bit rate of a V.90 modem is asymmetric. (5 marks) Q2. (a) With the aid of diagrams outline the essential features of ASK and FSK modulation (8 marks) (b) Draw a clearly labelled block diagram of an FSK demodulator (5 marks) (c) A telephone line has a bandwidth of 3500 Hz and a Signal-To-Noise ratio of 33dB. Determine the maximum data rate for error free transmission. (6 marks) (Note log2X=3.32*log10X) (d) Explain the operation of Time Division Multiplexing. How can switching be achieved in a TDM system. (6 marks) Q3. (a) Write a short note on Bluetooth wireless communications technology (8 marks) (b) Explain the main types of CDMA that are currently available. What are the advantages and disadvantages of CDMA. (8 marks) (c) A Direct-Sequence Spread Spectrum (DS-SS) CDMA system requires 30 dB of continuous wave (CW) power interference rejection and employs a 10-stage shift register m-sequence pseudo-random generator to transmit a data message at 9600 bps on a 800MHz carrier. Determine the following parameters:- (i) Required chip rate of the code generator (3 marks) (ii) Spectral line spacing in the signal (3 marks) (ii) First-lobe bandwidth and sketch the resulting frequency spectrum. (3 marks)