Post on 17-Jan-2016
ECEN4523 Commo TheoryECEN4523 Commo TheoryLecture #35 9 November 2015Lecture #35 9 November 2015Dr. George ScheetsDr. George Scheetswww.okstate.edu/elec-engr/scheets/ecen4533www.okstate.edu/elec-engr/scheets/ecen4533
ECEN4523 Commo TheoryECEN4523 Commo TheoryLecture #35 9 November 2015Lecture #35 9 November 2015Dr. George ScheetsDr. George Scheetswww.okstate.edu/elec-engr/scheets/ecen4533www.okstate.edu/elec-engr/scheets/ecen4533
Read 8.3Read 8.3 Problems: 8.2-5, 6, & 9Problems: 8.2-5, 6, & 9 Quiz #8, 13 November (Live) [Chapter 8]Quiz #8, 13 November (Live) [Chapter 8]
Remote DL students Remote DL students << 20 November 20 November Design Problem Design Problem
Remote DL students Remote DL students << 13 November 13 November Late Designs AcceptedLate Designs Accepted
Cost = -1 point per Working DatyCost = -1 point per Working Daty
ECEN4523 Commo TheoryECEN4523 Commo TheoryLecture #36 11 November 2015Lecture #36 11 November 2015Dr. George ScheetsDr. George Scheetswww.okstate.edu/elec-engr/scheets/ecen4533www.okstate.edu/elec-engr/scheets/ecen4533
ECEN4523 Commo TheoryECEN4523 Commo TheoryLecture #36 11 November 2015Lecture #36 11 November 2015Dr. George ScheetsDr. George Scheetswww.okstate.edu/elec-engr/scheets/ecen4533www.okstate.edu/elec-engr/scheets/ecen4533
Problems: 8.3 – 1, 2, 4, & 6Problems: 8.3 – 1, 2, 4, & 6 Quiz #8, 13 November (Live) [Chapter 8]Quiz #8, 13 November (Live) [Chapter 8]
Remote DL students Remote DL students << 20 November 20 November Design Problem Design Problem
Remote DL students Remote DL students << 13 November 13 November Late Designs AcceptedLate Designs Accepted
Cost = -1 point per Working DayCost = -1 point per Working Day Quiz 7 ResultsQuiz 7 Results
Hi = 10, Low = 4.7, Ave = 8.03, Hi = 10, Low = 4.7, Ave = 8.03, σσ = 2.26 = 2.26
Channel Capacity (C)Channel Capacity (C) Bandwidth, Bit Rate, SNR, and BER relatedBandwidth, Bit Rate, SNR, and BER related Channel Capacity defines relationshipChannel Capacity defines relationship
C = Maximum reliable bit rate C = Maximum reliable bit rate C = W*Log C = W*Log22(1 + SNR) bps(1 + SNR) bps
Bandwidth sets the maximum Baud rateIf move too many Baud, symbols will smear.
SNR sets the maximum number ofdifferent symbols (the "M" in M-ary)you can reliably tell apart.
1999 Silk Road1999 Silk Road During dot.com boomDuring dot.com boom Company selling fiber optic gearCompany selling fiber optic gear Claim: Can move Tbps over 64 KHz BWClaim: Can move Tbps over 64 KHz BW Fiber optic laser center freq 160,000 GHzFiber optic laser center freq 160,000 GHz
Jitter around 64 KHzJitter around 64 KHz
101099 bps = 64000*Log bps = 64000*Log22(1 + SNR)(1 + SNR) 2215,62515,625 – 1 = SNR – 1 = SNR Calculator couldn't find SNR high enoughCalculator couldn't find SNR high enough
2nd Claim2nd Claim
Same time periodSame time period Claim: Claim:
Can move Exobits/sec over power linesCan move Exobits/sec over power lines Won't need fiber optic cablesWon't need fiber optic cables
Power Line CommunicationsPower Line Communications
Image SourceWikipedia
Transformers don't pass high frequency signals.
Power Lines act as AntennasPower Lines act as Antennas
Source: http://www.doobybrain.com/2008/02/03/electromagnetic-fields-cause-fluorescent-bulbs-to-glow/
Lizzy Borden Lizzy Borden Alleged Alleged
18921892Ax Ax
MurdererMurderer
Lizzie Borden took an axeLizzie Borden took an axe
And gave her mother forty whacks.And gave her mother forty whacks.
When she saw what she had doneWhen she saw what she had done She gave her father forty-one. She gave her father forty-one.
Bernoulli Trials & Binomial DistributionBernoulli Trials & Binomial Distribution You must have a two state experimentYou must have a two state experiment
Success or FailureSuccess or Failure Stable probabilitiesStable probabilities
You must be interested in the You must be interested in the numbernumber of successes (or failures)of successes (or failures) Specific order not importantSpecific order not important
The individual experiments must be The individual experiments must be Statistically IndependentStatistically Independent
Need P(Number of Outcomes)?Need P(Number of Outcomes)? 1) Binomial Distribution? 1) Binomial Distribution? 2) If no, think Conditional Probability2) If no, think Conditional Probability
Draw an event treeDraw an event tree Assign probabilitiesAssign probabilities
P(a1)
P(a2)
P(a3)
P(b1|a1)
P(b2|a1)
P(b4|a2)
P(b6|a3)
P(a1∩b1)
P(a2∩b3)
P(a1∩b2)
P(a2∩b4)
P(a3∩b5)
P(a3∩b6)
P(b3|a2)
P(b5|a3)