Communications Presentation 8

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Communications Presentation 8

• Answers to Homework 2
• Two-way Satellite links
• Transponder gain, Saturation, solving for X
• Check of Westar, RCA Satcom, TVRO
• Repeater ground stations
• Homework 3 Assignment
• Grameen loan models
• World power brokers (updates)
• Use of Oil profits for development

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ECE 410 Homework 2Due Wed, Jan 30

• I. Going to China
• Portland is at 45 36' N, 122 36' W
• Beijing, China is at 39 55' N, 116 25' E
• (a)   How many Km minimum distance is it from
  here to there?
• (b)   On a direct flight from Portland to
  Beijing how close do you come to the North Pole?

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• (a) Portland 4536/6045.6 N, 12236/60122.6 W
• Beijing 3955/6039.9 N, 11625/60116.4 E
• Angle A (180-122.6) (180-116.4)
  57.463.6 121 deg
• Side c 90-45.6 44.4 deg Side b
  90-39.9 50.1 deg
• Cos a Cos b Cos c Sin a Sin b Cos A
• Cos 44.4 x Cos 50.1 Sin 44.4
  x Sin50.1 x Cos122.6 0.169
• A arcCos 0.169 80.26 deg distance 2 x p x
  6,370 x 80.26/360 8,923 Km
• (b) First we solve for B Sin b/ Sin B Sin
  a/Sin A
• Sin 50.1 Sin (121) / Sin (80.26) Sin B
  B 80.26 deg
• In triangle with C 90 deg Sin c/Sin 90
  Sin b/ Sin B
• Sin b Sin BxSin c/Sin 90 Sin 80.26xSin
  44.4 0.467 b27.8 deg
• Distance to pole 2 x px 6,370 x 27.8/360
  3,094 Km

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II. Pointing at a satellite

• What is the direction to a Pacific Ocean
  synchronous satellite at 330 deg West longitude
  from the following cities (elevation and azimuth)
  
• (a)   Cuzco, Peru, at 14 S lat., 72 W long?
• (b)   Portland is at 45 36' N, 122 36' W ?
• (c)    Beijing, China is at 39 55 N, 116 25 E
  ?
• (Remember that the azimuth is measured clockwise
  from North.)

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(a) Cuzco q360-33072102 f14
rarccos(cos102xcos14)101.6 (b) Portland
q360-330122.6152.6 f45.5
rarccos(cos152.6xcos45.5)128.5(c) Beijing
q116.4-3086.4 f39.9 rarccos(cos86.4xcos39
.9)87.2

• (a) r 101.6 deg e arcCos(sin r /
  sqrt(1.0227-.302sin r) error
• F arctan(RexSinr/hRe-ReCosr
  )arctan(6370Sinr /3586063701-Cosr) 8.16deg
• 8.16 101.6 90 e 180 e 180 8.16
  101.6 90 -19.76 deg
• Az 360 arcsin (Sin 90 Sin 102/Sin 101.6)
  360-86.9 273.1
• (b) r 128.5 F 6.16deg e 180 - 6.16
  128.5 90 - 44.6 deg
• Az 180 Arcsin (sin 90sin152.6/sin128.5)
  180- 36 144 deg
• (c) r 87.2 F 8.63 deg e 180 8.63
  87.2 90 -5.8 deg
• Az 180 Arcsin (Sin 90 sin 86.4/Sin 87.2
  ) 180 87.7 267.7 deg

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Azimuth Definitions

• Cuzco Portland
  Beijing

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III. TWTA Power
The full coverage EIRP of the African Beam of the
Intlesat satellite is 39 dBw at C-Band. The
equivalent 3-db beam width is about 8 degrees by
10 degrees (a)   What is the gain of the
satellite transmit antenna? (b)   If the
equivalent maximum EIRP of the satellite is 41
dBw, how much power does each amplifier have to
transmit?

• (a) Gain Gt (139x139/8x10) 2415gt23.8 dB
• (b) EIRP WxGtgt W 23.8 41
• W41-23.8 17.2 dBW gt 52.5 Watts

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IV. Radio Broadcast

• We want to evaluate a satellite radio broadcast
  from the satellite for direct reception by
  hand-held radios at C-Band. The Bandwidth is 10
  kHz and the required C/N is 7 dB. The receiver
  antenna has only 3 dB gain.
• (a)         What is the effective receiver
  temperature in clear skies? There is a 0.5 dB
  loss from the wire antenna to the LNA, which has
  an 80 degrees K noise temperature. The Antenna
  temperature is 100 degrees K. (The antenna sees
  only part of the noisy earth.) The sky
  temperature is 7 degrees K.
• (b)         What is the effective temperature
  when there is rain causing 1.5 dB loss?
• (c)          How much EIRP is needed from the
  satellite for each channel radio broadcast.
  Include the rain loss.
• (d)         If we keep the receiver performance
  the same as above but change the radio frequency
  to L-Band, 1.4 GHz, what power is required?
  Assume no rain loss.

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Sirus Satellite2.315 GHz

• (a) La0.5dBgt 1.122 Tr80x1.122(1.122-1)290125
  .14 deg K
• Tr Ta 125.14 100 225.14 deg K
• (b) 1.5 dBgt1.41 Teff 225.14
  290(1.41-1)/1.41
• 225.1484.3309.4 deg K gt24.9 dB
• (c) Lfs-196.5 dB k-228.6 Gr 3dB B10,000 gt
  40 dB C/N7 dB
• EIRP B C/N k Lfs Gr Teff abs
• 407-228.6 196.5-324.91.5
  38.3 dBW
• (d) f4/f1.4 4/1.4 2.85 gt4.55 dB Lfs
  -196.52x4.55 -187.4 dB
• T 225.14 deg K gt 23.52 deg K
• EIRP 407-228.6 187.4 3 23.520
  26.32 dBW

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V. Community TV Relay

• An alternative to direct TV broadcast is to use a
  1.5-Meter diameter dish and receive and
  rebroadcast signals to the local community. That
  way local origination can be injected into the
  programs. TV requires 2 MHz and 7 dB C/N
• (a)   What is the effective temperature of the
  receiver? There is a 0.1 dB loss between the
  1.5-Meter antenna and the 80 degree K LNA. The
  antenna temperature is now 7 degrees. Sky
  temperature is 7 degrees. Rain loss is 1 dB.
• (b)   What is the antenna gain (assume 55
  efficiency)?
• (c)   How many channels can be fit into the 39 dB
  EIRP of the satellite? (Assume 34 dB is in the
  linear range.)
• (d)   How much of the 36 MHz band is used?

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AMC-12 Satellite North America South America,
Europe, Africa- C-band payload 72 x 36 MHz
Downlink EIRP 49 dBW at centerAmp type -
TWTA- 67 watts, Europe/ Africa Hemi Beam - 67
watts, South America Zone Beam- 33 watts, North
America Zone BeamC-band Frequencies - Uplink
5925 - 6425 MHz - Downlink 3700 - 4200
MHzAmp Redundancy 30 for 24/beam Beams -
North America Zone Beam 3703 MHz (H) 4199.5 MHz
(V) - South America Zone Beam 3703 MHz (V)
4199.5 MHz (H)- Europe/Africa Hemi Beam 3703
MHz (V) 4199.5 MHz (H)

• (a) 0.1 dBgt1.023 Tr 80x1.023 (1.03-1)290
  90.5 deg K
• Tr Ta 90.57 97.5 deg K rain loss
  1 dBgt 1.26
• sky noise 290 (1.26-1)/1.26 7/1.26
  59.85.5 65.3 deg K
• effective noise at receiver Teff 97.5 65.3
  162.8 gt 22.1 dB deg K
• (b) 4 GHz .075M Gr .55 4p p R2/l2 .55 (
  p D /l )2
• Gr .55 ( p 1.5 / .075 )2 2,171 gt 33.4
  dB
• (c) B 2 MHz gt 63 dB Hz C/N7
• EIRP B C/N k Lfs Gr Teff abs
• 63 7 -228.6 196.5 33.4
  22.1 1 27.6 dBW
• number of channels in 34 dB is 34-27.6 6.4
  dB gt 4.4channels
• (d) 4.4x 2 Mhz 8.8Mhz

With 49 Db EIRP you get 45 linear and 56 Channels
?
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TWO-WAY SATELLITE STATION
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4.5 Meter antenna for the station
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Down-Link Performance
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Up-Link Performance
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Combining Up and Down link Noise
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Power in Satellite and Ground Station as a
function of up-link and down-link C/N
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COST OF TWO-WAY STATION
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Choice of Up link Down Link Ratio
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Transponder Saturation
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Transponder Gain
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Determining X in the Satellite
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Check X for Westar Satellite
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Effect of X on Alaska Bush-Phone Network
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TVRO Uplink
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Latin American Satellite
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Repeater Configurations
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Compare Three Approaches for the same customer
characteristics.

• 1,000 ground stations each with 1.2 kB/sec (1,500
  Hz B and 15 dB C/N)
• Each station can receive from the other
• Duty cycle is 2 I.e. the satellite transmitter
  average power is given by Per channel power x
  1,000 / 50.
• Cost of satellite 3 Million/watt (linear).
• Cost of ground equipment from previous notes.

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Comparison
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Comparison (cont.)
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ECE 410 Homework number 3 Due, Wed. February 13

• I.   The Latin American Satellite has an ERP of
  39 dBw, a G/T of 2 dB/ degree K and saturation
  flux density of -92 dBw/ M2.
• (a)  What is the transponder gain when the power
  is backed off to the linear range?
• (b) What is the ratio of up-link to down-link C/N
  , X, for an ground receiver with 1.0 Meter
  diameter and total noise of 150 degrees K? (Use
  an efficiency of 65. Ignore rain absorption.)
• (c) What size power amplifier is needed to
  transmit a 100 kHx Bandwidth with 6 dB C/N total
  directly from one 1.0-Meter station to another?
• (d) How many carriers will the transponder carry
  in this direct service?

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ECE 410 Homework number 3 Due, Wed. February 13

• II. A Hub station for the Latin American
  Satellite will have a 5-Meter diameter antenna
  65 efficiency and a receiver noise of 100
  degrees K.
• (a)  How much power will each 1.0 Meter station
  need to transmit the 100 kB/s data stream to the
  larger Hub station? Total C/N is still 9 dB.
• (b) How many such carriers will the transponder
  carry now if each is on all the time? (Include
  only signals to the Hub station.)
• (c) Assume the links of each station is active
  only 10 of the time. How many stations can one
  transponder serve on the incoming links? Check
  both the power and bandwidth, assuming there is
  30 MHz of usable bandwidth.

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ECE 410 Homework number 3 Due, Wed. February 13_

• III. As an alternate design, the 5-Meter Hub
  station station will transmit n x 100,000 B/sec
  on a single carrier (saturated power) to the
  small stations.The bandwidth is ½ x n x
  100,000.(QPSK Modulation)
• (a) Assuming the required C/N is still 9 dB, how
  many channels (n) can be transmitted? Check both
  power and frequency limits.
• (b) What is the value of up-link and down-link
  C/N?
• (c) How much power is needed from the Hub
  station?

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VI Let me know what you will be researching for
your term projects by writing a paragraph or two.
Please email the paragraphs to me so I can
comment on them by return email
lusignan_at_ece.pdx.edu
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Grameen Model

• A bank unit is set up with a Field Manager and a
  number of bank workers, covering an area of about
  15 to 22 villages.
• The manager and workers start by visiting
  villages to familiarise themselves with the local
  milieu in which they will be operating and
  identify prospective clientele, as well as
  explain the purpose, functions, and mode of
  operation of the bank to the local population.
• Groups of five prospective borrowers are formed.
• Initially, only two of them are eligible for, and
  receive, a loan.
• The group is observed for a month to see if the
  members are conforming to rules of the bank.
• Only if the first two borrowers repay the
  principal plus interest over a period of fifty
  weeks do other members of the group become
  eligible themselves for a loan.
• Because of these restrictions, there is
  substantial group pressure to keep individual
  records clear. In this sense, collective
  responsibility of the group serves as collateral
  on the loan.

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Costal Ecuador Application

• Significant poverty exists in costal Ecuador in
  the rural areas north of Guayaquil
• Many, mostly women, in costal Ecuador do not have
  adequate housing or income

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The poor lack housing and job skills

• Many, mostly women, in costal Ecuador do not have
  adequate housing or income
• Grameen foundation provides training on bamboo
  home building and a loan for building bamboo
  homes. The women own the home.

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Business training is completed before making
microloan

• Together with the home building skills the poor
  are taught principles of running a small business
• This training must be complete before a microloan
  is made.
• The combination of home ownership and business
  skills help the poor raise themselves from
  poverty.

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G-8 Leaders at last summit

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G 8 Side Bars
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Report adds to urging against attack on
IranFebruary 6, 2007 The Sydney Morning Herald.

• LONDON Warnings of the dire consequences of
  military confrontation with Iran, and calls for a
  renewed diplomatic effort, are being issued on
  both sides of the Atlantic in a sign of the
  growing anxiety over the prospect of US or
  Israeli action.
• A coalition of foreign policy advisers,
  humanitarian organisations and peace groups was
  expected to issue a report overnight arguing that
  an attack on Iran, reportedly being contemplated
  by the US and Israel as a means of slowing down
  Iran's nuclear program, would backfire
  disastrously
• Sir Richard Dalton, Britain's former ambassador
  to Tehran, supported the report's conclusions.
• "Diplomacy has not been exhausted," he said.
  "Military action should be a last resort, used in
  self defence against an imminent threat, and we
  have not reached that position yet."

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• OPECOrganization of Petroleum Exporting
  Countries (OPEC) members include Algeria,
  Indonesia, Iran, Iraq, Kuwait, Libya, Nigeria,
  Qatar, Saudi Arabia, the United Arab Emirates and
  Venezuela.

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Top World Oil Net Importers, 2005 Country Net
Oil Imports (million barrels per day)1) United
States 12.42) Japan 5.23) China 3.14) Germa
ny 2.45) South Korea 2.26) France 1.97) India
1.78) Italy 1.69) Spain 1.610) Taiwan 1.0
Total World about 35 million barrels/day
OPECTable includes all countries that imported
at least 1 million bbl/d in 2005.
Just how much investment could come from OPEC
Nations?
BP Statistical Review2 Oil Gas
Journal3 World Oil4 World Total ww 1,201.332
1,317.447 1,119.615 Billion Barrels
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A Modest Proposal

• Assume 4 of Overcharge for oil goes to
  development resources of OPEC Development Fund
• Assume overcharge is 50 - 25 25/barrel
• i.e. 1/barrel for development funds
• 35 Million barrels/day imports gives 35x106x365x
  1.00
• 12.8x109 12.8 Billion/yr
• Worlds Poor population gt 1.6 Billion1.6x109
• Annual investment for poor 8/year
• Typical Rural Community of 10,000 would get
  80,000 investment /year from OPEC surcharge

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One generation to go before alternative fuels

• How long is remaining at current consumption of
  80 million barrels/day?
• Total reserves estimate 1,300 billion barrels.
• 1300x109/80x106x365 44 years
• With 118 million barrels/day.. 30 years

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Populationin Africa and Latin America is about
1.6 billions World growth below