Transcription of LINK BUDGET CALCULATIONS - ITU
{{id}} {{{paragraph}}}
Example: dental hygienist
LINK BUDGET CALCULATIONS - ITU
link BUDGETCALCULATIONSOtto KoudelkaInstitute of Communication Networks andSatellite CommunicationsTU characteristics of TX station RX station propagation noise, interference characteristics of satelliteNOISE noise voltage independent of frequency, white noisekTBRun42 k = 10-23J/K, Boltzmann noise temperatureNOISEfS(f)NOISE at very high frequencies thermal noise vanishes, only quantum noise remains Noise powerkTBBNN 0 UPLINKEARTH -SPACERE arthGround StationSatelliteCARRIER POWER Inverse square law power ( ) power effective antenna aperture antenna gainAGRPCeffTT24 ANTENNA FORMULA effective apertureAGAeff 42 2222244 DDG 4422 GRGPCRTTCARRIER POWERGPEIRPTT RLs42free-space lossCARRIER/NOISE RATIOBTkNCNNCCs kBTGRGPNCsRTT1/42 kTGRGPNCsRTTo1/42 Signal/noiseratioSignal/noisedensityFIGU RE OF MERIT G/T [dB/K] important characteristic for satellite ground stationLINK BUDGET calculation figures may vary widely EIRP high free-space loss very high receive carrier power very low logarithmic representation advantageousLOGARITHMIC REPRESENTATION Signal-to-noise ratio [dB] )log(10)log(10)log(10)log(10/4log20)log( 10)log(10 BkTGRGPNCsRTT BkTGLEIRPdBHzKdBJKdBdBdBWNC][]/[]/[][][/ C/No carrier power / noise density Normaliset to 1 Hz noise bandwidth kTGLEIRPKdBJKdBdBsdBWoNC]/[]/[][][/ C/T sometimes used in link budgets in [dBW/K] leaves out k = dB(J/K) at the end of calculation B, k considered TGLEIRPKdBdBsdBWTC/]/
LINK BUDGET CALCULATION • figures may vary widely –EIRP high –free-space loss very high –receive carrier power very low • logarithmic representation advantageous. LOGARITHMIC REPRESENTATION • Signal-to-noise ratio [dB] 10log( ) 10log( ) 10log( ) 10log( ) 10log( ) 20log 4 / 10log( ) T k B P G R G N C s
Tags:
Information
Domain:
Source:
Link to this page:
Please notify us if you found a problem with this document: