Course Introduction. EE 179, Lecture 1, Handout #2. EE 179, March 31, 2014 Lecture 1, Page 1

Size: px

Start display at page:

Download "Course Introduction. EE 179, Lecture 1, Handout #2. EE 179, March 31, 2014 Lecture 1, Page 1"

Lynne Carroll
10 years ago
Views:

1 Course Introduction EE 179, Lecture 1, Handout #2 EE 179, March 31, 2014 Lecture 1, Page 1

2 Course Information Instructor: John Gill, Packard 266, Office hours: TBA Class homepage: Coursework for scores. Prerequisites: EE 102A or equivalent Textbook: Lathi & Ding, Modern Digital and Analog Communications Systems, 4th ed. Weekly homework assignments due on Fridays Grading: HWs 20%, midterm 30%, final 50% EE 179, March 31, 2014 Lecture 1, Page 2

3 Class Policies Homework policy Assigned on Wednesdays, due following Wednesday at 5pm. Penalty 25% credit per day late. Up to 3 students can collaborate on 1 writeup. All collaborators must work out all problems. Examination policy Exams must be taken at their scheduled times. Exceptions only for good reason. Midterm: Friday, May 9, open book, open notes Final: Friday, June 6, 12:15 3:15pm, open book, open notes EE 179, March 31, 2014 Lecture 1, Page 3

All collaborators must work out all problems. Examination policy Exams must be taken at their scheduled times.

4 Course Syllabus Communication systems today Key concepts in communications Fourier transform review and examples Energy/power spectral density; autocorrelation Noise and signal-to-power ratio Amplitude modulation Frequency modulation Digital modulation Error detection and correction EE 179, March 31, 2014 Lecture 1, Page 4

autocorrelation Noise and signal-to-power ratio Amplitude modulation Frequency

5 Early Communication Systems Telegraph 1830, Joseph Henry 1832, Pavel Schilling 1837, Samuel B. Morese, Morse code 1844, What Hath God Wrought Telephone 1876, Alexander G. Bell ( Watson come here; I need you. ) 1888, Strowger stepper switch 1915, US transcontinental service (requires amplifiers) Wireless telegraphy Radio 1895, Jagadish Chandra Bose builds radio transmitter 1896, Marconi patents radio telegraphy 1901, Marconi, first transatlantic transmission 1906, Reginald Fessendend, first broadcast 1920, first commercial AM radio station (Montreal XWA CINW) EE 179, March 31, 2014 Lecture 1, Page 5

) 1888, Strowger stepper switch 1915, US transcontinental service (requires amplifiers) Wireless telegraphy Radio 1895, Jagadish Chandra Bose builds

6 Communication Systems Today Public Switched Telephone Network (PSTN) for voice, fax, modem Radio and TV broadcasting (covered later in the course) Citizens band radio; ham short-wave radio Computer networks (LANs, WANs, and the Internet) Satellite systems (pagers, voice/data, movie broadcasts) Cable television (CATV) for video and data Cellular phones Bluetooth GPS EE 179, March 31, 2014 Lecture 1, Page 6

networks (LANs, WANs, and the Internet) Satellite systems (pagers, voice/data, movie broadcasts)

7 Communication Systems Then EE 179, March 31, 2014 Lecture 1, Page 7

8 Communication Systems Now EE 179, March 31, 2014 Lecture 1, Page 8

9 PSTN Design Local exchange Handles local calls Routes long distance calls over multiplexed high-speed connections Circuit switched network tailored for voice Faxes and modems modulate data for voice channel DSL uses advanced modulation to get Mbps EE 179, March 31, 2014 Lecture 1, Page 9

for voice Faxes and modems modulate data for voice channel DSL uses

Cellular System Basics Geographic region divided into hexagonal cells 1 Frequencies/timeslots/codes are reused at spatially-separated locations. (Analog systems use FD, digital systems use TD or CD.

10 Cellular System Basics Geographic region divided into hexagonal cells 1 Frequencies/timeslots/codes are reused at spatially-separated locations. (Analog systems use FD, digital systems use TD or CD.) Co-channel interference between same color cells Handoff and control coordinated through cell basestations 1 proposed in 1947 by Douglas H. Ring and W. Rae Young, Bell Labs engineers EE 179, March 31, 2014 Lecture 1, Page 10

) Co-channel interference between same color cells Handoff and control coordinated through cell

11 Cellular Phone Backbone Network Mobile telephones depend on the PSTN except for mobiles within the same MTSO (mobile telephone switching office) EE 179, March 31, 2014 Lecture 1, Page 11

12 Local Area Networks (LAN) Local means every computer can hear every other computer Packet switching instead of circuit switching (no dedicated channels) Data is broken down into packets Originally proprietary protocols; e.g., Ethernet was a collaboration between Intel, DEC, and Xerox. (DEC?) EE 179, March 31, 2014 Lecture 1, Page 12

13 Wireless Local Area Networks (WLAN) WLANs connect local computers (100m range) to an access point As with LANs, data is broken down into packets Channel access is shared (random access) Access protocols for WLANs are much more complex than for LANs Backbone Internet provides best-effort service (no QOS guarantee) EE 179, March 31, 2014 Lecture 1, Page 13

(random access) Access protocols for WLANs are much more complex than for LANs Backbone

14 Wide Area Networks; the Internet EE 179, March 31, 2014 Lecture 1, Page 14

15 Satellite Systems Satellites cover very large areas Different orbit heights: GEOs (39000 Km) versus LEOs (2000 Km) Optimized for one-way transmission, such as radio (XM, DAB) and television (SatTV) broadcasting Latency (round trip delay) can be a problem EE 179, March 31, 2014 Lecture 1, Page 15

transmission, such as radio (XM, DAB) and television (SatTV) broadcasting

16 Bluetooth Ericsson, 1994, named for King Harald Blåtand Gormsen Intended as replacement for cables, such as RS-232 Now used for input devices, cell phones, laptops, PDAs, etc. Short range connection ( m) Bluetooth 1.2 has 1 data (721 Kbps) and 3 voice (56 Kbps) channels, and rudimentary networking capabilities EE 179, March 31, 2014 Lecture 1, Page 16

Short range connection (10 100 m) Bluetooth 1.

Long Distance Connection and WAN

Lecture 6 Long Distance Connection and WAN Digital Telephone, PCM and Nyquist Sampling Theorem DSU/CSU, T Line Series and OC line Series Local Loop DSL Technologies - ADSL, HDSL, SDSL, VDSL Cable Modem