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    Link Budget (1) : Muhamad Asvial

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    zarar satti
    The document discusses link budget and system planning for mobile satellite systems. It covers performance metrics like quality of service and availability. The basic concepts of carrier transmission budget are explained, including antenna gain, transmitted power, effective isotropic radiated power (EIRP), and free space loss. Noise sources in earth stations and payloads are characterized. Formulas for earth station system G/T and noise temperature are provided. Examples of noise contribution budgets and calculations for G/T of a C-band earth station are given.

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    Link Budget (1) : Muhamad Asvial

    Uploaded by

    zarar satti
    74 views27 pages
    The document discusses link budget and system planning for mobile satellite systems. It covers performance metrics like quality of service and availability. The basic concepts of carrier transmission budget are explained, including antenna gain, transmitted power, effective isotropic radiated power (EIRP), and free space loss. Noise sources in earth stations and payloads are characterized. Formulas for earth station system G/T and noise temperature are provided. Examples of noise contribution budgets and calculations for G/T of a C-band earth station are given.

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    The document discusses link budget and system planning for mobile satellite systems. It covers performance metrics like quality of service and availability. The basic concepts of carrier transmission budget are explained, including antenna gain, transmitted power, effective isotropic radiated power (EIRP), and free space loss. Noise sources in earth stations and payloads are characterized. Formulas for earth station system G/T and noise temperature are provided. Examples of noise contribution budgets and calculations for G/T of a C-band earth station are given.

    Copyright:

    © All Rights Reserved
    Download as PDF, TXT or read online from Scribd
    Download as pdf or txt
    74 views27 pages

    Link Budget (1) : Muhamad Asvial

    Uploaded by

    zarar satti
    The document discusses link budget and system planning for mobile satellite systems. It covers performance metrics like quality of service and availability. The basic concepts of carrier transmission budget are explained, including antenna gain, transmitted power, effective isotropic radiated power (EIRP), and free space loss. Noise sources in earth stations and payloads are characterized. Formulas for earth station system G/T and noise temperature are provided. Examples of noise contribution budgets and calculations for G/T of a C-band earth station are given.

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    of 27

    Link Budget (1)

    Lecture 8

    MUHAMAD ASVIAL
    Center for Information and Communication Engineering Research (CICER)
    Electrical Engineering Department, University of Indonesia
    Kampus UI Depok, 16424, Indonesia
    asvial@ee.ui.ac.id
    http://www.ee.ui.ac.id/cicer
    Link budget & system planning

    1
    Mobile System

    2
    Performance

    (i) QoS – b.e.r.


    – 10-4 if speech
    – 10-6 – 10-8 data (extra coding)
    (ii) Availability
    – 95%
    – Channel conditions

    3
    Basic Transmission

    4
    Carrier Transmission Budget
    -Antenna Gain-
    The antenna gain is defined as the ratio of the power per unit solid angle received/radiated by the ant
    enna in a given direction to the power per unit solid angle received/radiated by an isotropic anten
    na supplied with the same power.

    5
    Basic Transmission

    6
    Basic Transmission

    7
    Antenna radiation pattern

    Antenna radiation pattern = gain variations as a function of the a


    ngle  relative to boresight

    8
    Transmitted power in a given
    direction

    9
    Predicted coverage areas for the
    HOTBIRD satellites
    (a) Superbeam
    (b) Widebeam
    (courtesy of EUTELSAT)
    10
    Effective isotropically radiated
    power (EIRP)

    11
    Exercise (1) - Carrier Transmission B
    udget

    • Given
    – Power fed to antenna: PT = 10W
    – Antenna gain (at boresight): GTmax = 40dB
    – Distance: R = 36000km (earth to geostationary
    satellite
    • Calculate
    – Transmitter EIRP in dB(W) 12
    – Flux density at receiver in dB(W/m2)
    Down Path

    13
    GEO - Geometry

    14
    Earth station from the geostationary orbit

    • Satellite
    – Height h above the equator
    – Sub-satellite point, longitude ΦS
    • Earth station
    – Latitude E, longitude ΦE
    – Relative longitude satellite = (ΦE – ΦS) = ΦES

    15
    Exercise (2) – Carrier Transmission
    Budget

    • Given
    – Uplink frequency = 14GHz
    – Earth station
    • Power fed to the antenna: PT=100W
    • Antenna diameter: D=4 (efficiency =0.6)
    • Location: Bercenary (France)
    – Latitude = 48º13’07”N
    – Longitude = 03º53’13”E
    – Satellite
    • Receiving antenna gain at boresight: GRmax=40dB
    • Location: 7ºE (EUTELSAT 1-F2)
    • Calculate
    – EIRP of earth station
    – Free space loss
    – Received power
    16
    Noise in an Earth Station

    G/T Ref

    rf if

    Ta Tf TD/L BASEBAND
    LNA IPA DEMOD QoS
    TLNA TIPA Lo (BER)

    DOWN CONV
    C/NOD
    Ts

    – Noise comes from:


    • Ta= picked up by antenna from outside Pa ( =effective noise)
    kB
    • Tf= lossy feeder
    • TLNA, TIPA= amplifiers in receiver chain
    • TD/C= down converter
    – Refer all noise to a reference plane into the LNA
    17
    Noise in a Payload

    G/T Ref

    Cu CD

    D/C

    C/Nou
    eirps

    • Noise comes from:


    – Antenna received noise –earth + galaxy
    – Feeder lossy noise (nb.290K)
    – Equipment noise –amps / D/C etc. added in same way as fo
    r earth station.

    18
    19
    Noise Characterisation (1)

    20
    Noise Characterisation (2)

    21
    Noise contribution of an attenuator

    22
    Earth-station system G/T
    and noise temp.
    Ref

    Ta Tf TLNA
    TIPA TD/C
    LdB LNA IPA D/C
    GLNA GIPA
    TLNA
    TIPA
    g LNA LD/C
    TD/C
    g LNA xg IPA
    1
    ( 1 )Tf
    l TIPA T DC
    1
    xTa
    Ts  Ta  (1 -  )Tf  TLNA    ...
    l gLNA gLNA x gIPA
    LdB  10log(l), α  1
    l
    GdB  10log(g)
    Gain of antenna at reference  (Ga - L)dB
    G  (Ga  L)  10Log(Ts)dB/K
    T
    23
    Earth station antenna noise temperature
    Examples (clear sky conditions)

    24
    Exercise (3) - Noise Contribution
    Budget

    • Operating frequency = 12 GHz


    • LNA: TLNA = 150K, GLNA = 50dB
    • MIXER: TMX = 850K, GMX = -10dB
    • IF AMP: TIF = 400K, GIF = 30dB
    • Calculate
    – Receiver effective input noise temperature TR
    – Receiver noise figure
    25
    Exercise (4) - G/T of C-band earth st
    ation

    • Dish=15m, n=70% Feeder


    if
    LNA IPA D/C
    • Ta=30K
    • Tf=290K
    • Loss f=0.5dB
    • TLNA=35K
    • GLNA=30dB
    • FIPA=3dB
    • GIPA=20dB
    • TD/C=1000K
    • Loss D/C=-10dB
    • Calculate the earth station G/T
    – What are the advantages of trading off dish size and LN
    A temp.?

    26

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