Digital communication Systems Lecture Slides, Lecture notes of Digital Communication Systems

Download Digital communication Systems Lecture Slides and more Lecture notes Digital Communication Systems in PDF only on Docsity!

Lecture 1: EE 179 Course Introduction

John M Pauly

September 19, 2021

Course Introduction

Professor Andrea Goldsmith

Next-generation Cellular Wireless Internet Access Wireless Multimedia Sensor Networks Smart Homes/Spaces Automated Highways In-Body Networks All this and more …

Based on Notes from John Gill

Course Information

I (^) Instructor: John Pauly, pauly@stanford.edu

Packard 358, 650-723- Office hours: Th 11-12.

I (^) Class homepage: http://ee179.stanford.edu

I (^) Prerequisites: EE 102A or equivalent

I (^) Recommended Textbook: Lathi & Ding, Modern Digital and Analog

Communications Systems, 5th ed.

I (^) Weekly homework/lab assignments due on Fridays

I (^) Grading: HW and Labs 40%, midterm project 20%, final project 40%

Assignments and Projects

I (^) Homework and Labs

I (^) Assigned on Fridays, due following Friday at class time. I (^) You are free to talk with other students about the homework and problems, but everyone should turn in their own write up.

I (^) Midterm and Final Projects

I (^) Midterm will be a short project (essentially a lab you do on your own) I (^) The final project topic will be given to you. Last time it was decoding the digital packets that planes use to identify themselves. I (^) Final project presentations will be during the scheduled final time, Wed 8, form 7-10 PM. You will have 10 minutes to present your project and results.

Amateur Radio License

I (^) We’ll be having a zoom class on getting your Amateur Radio License I (^) This is a great way to really learn and use what we cover in this class I (^) Thursday evenings at 7 PM, starting next week I (^) We’ll give you a free VHF/UHF handheld radio when you pass I (^) If we get the Lime SDR’s you will need a license to be able to transmit.

Course Outline

I (^) Modern communications systems

I (^) Focus on transport layer. How do you encode information on a carrier?

I (^) Signal processing in 2 πf , instead of ω as in 102A

I (^) Finding your way around the RF spectrum

I (^) Analog Systems I (^) Amplitude modulation (AM, SSB, QAM) I (^) Pulse modulation (PAM, PWM, PPM) I (^) Angle modulation (FM, PM, PSK, and FSK)

I (^) Digital systems I (^) Sampling and Quantization I (^) Pulse code modulation (PCM) I (^) Digital modulation (PAM, ASK, FSK, PSK, QPSK, and QAM) I (^) Line Coding and ISI

I (^) SNR and performance

West Coast End of the AT&T Transcontinental Wireless

Telegraph

Bixby Park, Palo Alto Baylands

Communication Systems Today

I (^) Public Switched Telephone Network (PSTN) for voice, fax, modem

I (^) Radio and TV broadcasting

I (^) Citizens’ band radio; ham short-wave radio

I (^) Computer networks (LANs, WANs, and the Internet)

I (^) Satellite systems (pagers, voice/data, movie broadcasts)

I (^) Cable television (CATV) for video and data

I (^) Cellular phones

I (^) Bluetooth

I (^) GPS

I (^) Many others...

Cellular System Basics

STATIONBASE

I (^) Geographic region divided into hexagonal cells^1

I (^) Frequencies/timeslots/codes are reused at spatially-separated locations.

(Analog systems use FD, digital systems use TD or CD.)

I (^) Co-channel interference between same color cells

I (^) Handoff and control coordinated through cell basestations

(^1) proposed in 1947 by Douglas H. Ring and W. Rae Young, Bell Labs engineers

Cellular Phone Backbone Network

Mobile telephones depend on the PSTN — except for mobiles within the same MTSO (mobile telephone switching office)

BS BS

MTSO (^) PSTN MTSO

BS

San Francisco

New York

InternetInternet^ Internet

Wireless Local Area Networks (WLAN)

01011011 Wireless Access Point

0101 1011

I (^) WLANs connect “local” computers (100m range) to an access point

I (^) As with LANs, data is broken down into packets

I (^) Channel access is shared (random access)

I (^) Access protocols for WLANs are much more complex than for LANs

I (^) Backbone Internet provides best-effort service (no QOS guarantee)

Wide Area Networks; the Internet

Bluetooth

I (^) Ericsson, 1994, named for King Harald Bl˚atand Gormsen I (^) Intended as replacement for cables, such as RS- Now used for input devices, cell phones, laptops, PDAs, etc. I (^) Short range connection (10–100 m) I (^) Bluetooth 1.2 has 1 data (721 Kbps) and 3 voice (56 Kbps) channels, and rudimentary networking capabilities