EE521 Analog and Digital Communications Today some topics will be presented on the whiteboard. The slides will be updated on the web site in a few days. EE521 Analog and Digital Communications James K. Beard, Ph. D. jkbeard@temple.edu Tuesday, February 1, 2005 http://astro.temple.edu/~jkbeard/ 11/30/2018 Week 2

Essentials Text: Bernard Sklar, Digital Communications, Second Edition Prerequisites Consent of Instructor (Dr. Silage) SystemView (CD-ROM with text) Office E&A 709 Hours TBA, Tuesday afternoons planned MWF 10:30 AM to 11:30 AM added 11/30/2018 Week 2

Today’s Topics SystemView Signals and Noise Detection of Binary Signals Inter-symbol interference Equalization Discussion (as time permits) 11/30/2018 Week 2

Homework Problem Sklar Problem 2.4 Page 101 Given in the files from the CD-ROM Basis of analysis is Fourier series Infinite series of pulses in time domain is infinite series of pulses in frequency domain (text section 2.4.1.1 pp 63-66) 11/30/2018 Week 2

Sklar’s Answer Solution is given as SystemView file Sum_of_cosines.svu Number of tokens>10 puts Student version in no-save mode Fourier transform of train is (Sklar, equations (2.5), (2.6), (2.8) The issue is that the aux files problem 2.4 appear not to be related to the textbook problem 2.4. 11/30/2018 Week 2

The Homework Problem Basis is Principle Block diagram of Figure 2.1 Natural sampling, 2.4.1.2 pp. 66-68 As opposed to impulse sampling, 2.1.1.1 Principle Sampling replicates system spectra Distance between replicated spectra is the signal bandwidth Block diagram of Figure 2.1 Mixes one of these replicated spectra to baseband Low pass filters to recover the signal Problem_2_4.svu 11/30/2018 Week 2

Formatting and Baseband Modulation Topics from Text Chapter 2 2.5, Sources of Corruption 2.6, Pulse Code Modulation 2.7, Uniform and Non-uniform Quantization 2.8, Baseband Modulation Corruption: noise, fading, interference PCM: Simple digital modulation Quantization: the ADC and data compression Baseband modulation: synthesizing the signal 11/30/2018 Week 2

Sklar Chapter 2 Legend: From other sources Essential Information Message symbols Optional Channel symbols X M I T Format Source encode Encrypt Channel encode Multi-plex Pulse modulate Bandpass modulate Freq-uency spread Multiple access Digital input Channel impulse response Bit stream Synch-ronization Digital baseband waveform Digital bandpass waveform Channel Digital output R C V Format Source decode Decrypt Channel decode Demul-tiplex Detect Demod-ulate & Sample Freq-uency despread Multiple access To other destinations Channel symbols Information sink Message symbols 11/30/2018 Week 2

Spectral Attributes We are looking for better bandwidth efficiency Obtained by modulations with More compact spectra Less interference between symbols 11/30/2018 Week 2

M-ary Pulse Modulation Base modulation types Pulse Amplitude Modulation (PAM) Pulse Position Modulation (PPM) Pulse Duration Modulation (PDM) Number of different pulse shapes in a character is M, hence M-ary modulation 11/30/2018 Week 2

Baseband Demodulation and Detection Signals and noise Detection of binary signals in Gaussian noise Inter-symbol interferencie Equalization 11/30/2018 Week 2

Signals and Noise Base problem is symbol error Additive noise can bridge the difference between waveforms for different symbols Symbol error rate is function of SNR Modulation type Basic figure of merit is bit energy divided by noise power spectral density 11/30/2018 Week 2

Summary Course overview: we will learn how to implement critical technologies for digital communications Course is integrated with a follow-on next semester Baseband signals are where we do modulation == formatting for the channel SystemView lets us have most of the benefits of a lab with minimum time 11/30/2018 Week 2

Feedback Around the room Please let me know What your background is Design SystemView Communications What you expect from this course 11/30/2018 Week 2

Text and Assignment Text Assignment: Read Text Benard Sklar, Digital Communicatinons ISBN 0-13-084788-7 SystemView User's Manual, Elanix, Inc http://www.elanix.com/ http://www.elanix.com/pdf/SVUGuide.pdf Assignment: Read Text Chapter 3, 3.1, 3.2, 3.3, 3.4 Load SystemView and examine the samples and demos Browse appendices of text for review and supplementary material Look at TUARC K3TU, websites http://www.temple.edu/ece/tuarc.htm http://www.temple.edu/k3tu 11/30/2018 Week 2