Satellite Communication (lecture#9)
Satellite CommunicationLink BudgetLecture # 9Link BudgetIntroductionOverall design of a complete satellite communicationssystem involves many complex trade-offs to obtain a costeffective solutionsFactors which dominate are DownlinkEIRP, G/T and SFD of SatelliteStation Antenna Frequency Interference EarthGeneral ArchitectureTransmit Earth Station EIRP downUplinkDownlinkG/T & SFDUplink Path LossRain Attenuation Antenna GainPower of AmplifierUplinkDownlink Path LossRain Attenuation EIRP UpPath LossRain AttenuationG/T ESGtPtLNA / LNBHPA / Transceiver1
SatelliteReceiving Earth Station G/T EIRP SFD (Saturated Flux Density)Amplifier Characteristic (Equivalent Isotropic Radiated Power) Antenna GainLNA /LNB Noise TemperatureOther EquipmentDownlink Path LossRain AttenuationSignal Power CalculationAntenna GainAntenna Beam widthG η (Π * d / λ) 2 [dBi]θ3dB 70 * C / dfWhere,λ C/f,C Speed of lightf frequency of interestη efficiency of antenna (%),d diameter of antenna (m)EIRPIs the effective radiated power from thetransmitting side and is the product of theantenna gain and the transmitting power,expressed asEIRP Gt Pt –LfSignal Power Calculation[dB][degrees]Where,C 3x108 m/s (Velocity of Light)Signal Power (Pr)Pr EIRP – Path Loss Gr (sat)[dB]Where,Path Loss (4ΠD / λ) 2D is the Slant Range (m)Where,Lf is the Feed Losses2
Noise CalculationThermal NoiseIs the noise of a system generated by the randommovement of electronics, expressed asNoise Power KTBWhere,K (-228.6 dBJ/K)T Equivalent Noise Temperature (K)B Noise Bandwidth of a receiverEffective TemperatureNoise TemperatureTe T1 (T2/G1)Ts Tant / Lf (1-1/Lf)TfWhere,Where ,Tant Temperature of antennaLf Feed LossesTf Feed TemperatureT1 Temperature of LNAT2 Temperature of D/CG1 Gain of LNAEffective TemperatureG/T (Gain to System Noise Temperature) Tsys Ts Te Being a first stage in the receiving chain, LNA is themajor factor for the System Temperature CalculationLower the noise figure of LNA lower the systemtemperatureAntenna temperature depends on the elevation angle fromthe earth station to satellite This is the Figure of merit of any receivingsystemIt is the ratio of gain of the system andsystem noise temperatureG/T G-10log (Tsys)[dB/K]3
Eb/No (Energy per bit per Noise Power Density)Link AnalysisC/N Uplink(C/N)u (EIRP)e-(Path Loss)u (G/T)sat-K-Noise BW [dB] C/N Downlink(C/N)d (EIRP)sat-(Path Loss)d (G/T)e-K-Noise BW [dB] C/N Total(C/N)T-1 (C/N)u-1 (C/N)d-1 [C/I)IM-1 [C/I]adj-1 [C/I]xp-1Carrier Parameters Solution - Carrier Performance: Eb/No ThresholdBit Error Rate (BER)Rain Attenuation[dB]Is the performance criterion for any desireBERIt is the measure at the input to thereceiverIs used as the basic measure of how strongthe signal isDirectly related to the amount of powertransmitted from the uplink stationEb/No (C/N)T Noise BW – Information RateBit Error Rate (BER) Whyis it used? - To represent the amount of errorsoccurring in a transmission- To express the link quality What is it?- BER is an equipment characteristic- BER is directly related to Eb/No- BER improves as the Eb/Nogets largerP 1/2 e -Eb/NoCarrier Parameters Performance: Application specific Digital voice links: BER threshold 10-3 Data links:- BER threshold: 10-4(with P Probability of error)Carrier Parameters Performance: Typical Eb/No values for different FECEb/No forFEC 1/2 (dB)Eb/No forFEC 3/4 (dB)Eb/No forFEC 7/8 10-710-810-104
Rain Attenuation Questions?Performance - Rain Attenuation: Availability TORain Margins LTESAELITTypically 99.60 % for Ku-BandTypically 99.96 % for C-BandE/S Performance - Additional Margins: Adjacent Satellite Interference (ASI)Interference Margins5
Satellite Communication Lecture # 9 Link Budget Link Budget Introduction Overall design of a complete satellite communications system involves many complex trade-offs to obtain a cost-effective solutions Factors which dominate are Downlink EIRP, G/T and SFD of Satellite Earth St
Introduction of Chemical Reaction Engineering Introduction about Chemical Engineering 0:31:15 0:31:09. Lecture 14 Lecture 15 Lecture 16 Lecture 17 Lecture 18 Lecture 19 Lecture 20 Lecture 21 Lecture 22 Lecture 23 Lecture 24 Lecture 25 Lecture 26 Lecture 27 Lecture 28 Lecture
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the satellite output power to the maximum level, additional noise is introduced into the link from satellite to hub. Therefore, an accurate calculation of the SNR for the entire RTN link must consider: 1. the SNR of the terminal-to-satellite link 2. the SNR of the satellite-to-hub link When the output power of the satellite is at a maximum, SNR .
c. Satellite: Internet access provided through satellites orbiting the Earth. Satellite service requires a satellite Internet subscription from an Internet satellite service provider and a satellite dish. Carriers that provide satellite Internet service are DIRECTV, Dish Network, HughesNet, and Wildblue. d.
Lecture 1: Introduction and Orientation. Lecture 2: Overview of Electronic Materials . Lecture 3: Free electron Fermi gas . Lecture 4: Energy bands . Lecture 5: Carrier Concentration in Semiconductors . Lecture 6: Shallow dopants and Deep -level traps . Lecture 7: Silicon Materials . Lecture 8: Oxidation. Lecture
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Partial Di erential Equations MSO-203-B T. Muthukumar tmk@iitk.ac.in November 14, 2019 T. Muthukumar tmk@iitk.ac.in Partial Di erential EquationsMSO-203-B November 14, 2019 1/193 1 First Week Lecture One Lecture Two Lecture Three Lecture Four 2 Second Week Lecture Five Lecture Six 3 Third Week Lecture Seven Lecture Eight 4 Fourth Week Lecture .
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