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Sam Parrotte Joshua Young Jason Hernandez November 19 th 2013 1.

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Presentation on theme: "Sam Parrotte Joshua Young Jason Hernandez November 19 th 2013 1."— Presentation transcript:

1 Sam Parrotte Joshua Young Jason Hernandez November 19 th 2013 1

2 1.What is Digital Modulation? 2.Why use it? 3.How is it related to Embedded Systems? 4.Sample Forms of Digital Modulation 5.Ethernet 2

3 Process of using an analog carrier signal to contain discrete information Digital-to-analog modulation of data Analog-to-digital demodulation of carrier Analog Modulation vs. Digital Modulation Similar: Manipulates a carrier wave to transmit data Different: Digital has a finite number of states the carrier will be in => often known as keying 3

4 /Amfm3-en-de.gif -modern-digital-modulation-techniques 4

5 5 Demodulation techniques offer beneficial recovery abilities Multiple parties share mediums to communicate information Commonly shared mediums: o Cable o Air

6 content/uploads/2012/06/WifiSpectrumComparisonFounten.png series1.jpg/300px-XBee-pro-series1.jpg Xbee Spectrum 6

7 7

8 Router Access Send information to a server Interact with Wifi devices Direct communication between devices When sending high data rates When multiple devices share a medium Commercial RF Product Cant use predesigned boards Must understand individual components 8 WIRELESS-AT02876-REB212BSMA-Hardware-User- Manual_Application-Note.pdf

9 9

10 10 Uses: Caller ID 3G Dial up Modem

11 11 Uses: Optical Fiber Laser Communication Short distance RF

12 12 f(t) = cos(ωt + φ) s/thumb/3/30/MLG0013-binary- phase-shift-keying.jpg/300px- MLG0013-binary-phase-shift- keying.jpg Uses: Cable Modem RFID Digital Video Broadcasting

13 13

14 14 16 States 4 Bits/Period (4^2 = 16) Utilizes both Amplitude and phase

15 15 Transmission: PAM Signal = Carrier Waveform x Digital pulses Reception: Digital Data (in pulses) = PAM Signal / Carrier Waveform Uses: Ethernet


17 Contains twisted pairs to limit amount of induced noise Various Ethernet types, speeds from 10 Mbit/s up to 100 Gbit/s 17

18 4 sets of twisted pair connections Transmit/Receive pairs Data sent in packets also called Ethernet Frames 18

19 Most common Ethernet interfaces use PAM-5 (10BASE-T, 100BASE-TX) 5 voltage levels for modulation [-2, -1, 0, 1, 2] 10GBASE-T uses PAM-16 (DSQ128) for modulation 19

20 Digital Modulation is the process of modulating a discrete signal in an analog one Carrier signals are useful where a bus may not be practical or possible Digital modulation is widely used in many forms of electromagnetic communication 20

21 freq-allocations-chart_big.jpg freq-allocations-chart_big.jpg Hardware-User-Manual_Application-Note.pdf Hardware-User-Manual_Application-Note.pdf 21

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