Satellite Communication System Engineering Training Course

ASOSIASI SATELIT INDONESIA (ASSI)Via Renata – cimacan, Puncak, 25-27 Oktober 2011

Soal Quiz LINK BUDGET & TRANSPONDER MANAGEMENT

Sebuah satelit dengan station keeping = 0.05, EIRP = 40dBw, G/T=2dB/°K, SFD=-90dBw/m², digunakan untuk sistem VSAT dengan Outroute = 512KBPS, Inroute = 64KBPS.Jika carrier dimodulasi dengan tipe QPSK dengan FEC=1/2 dan informasi lainnya adalah :a. Aggregate Input Backoff = 5 dB dan Output Backoff = 3 dBb. Antena untuk VSAT, Hub=6meter, Remote=1.8meter. c. C/Im = 20 dB, C/Xp = 30 dB, C/Iadj = 22 dBd. Gain 1m antena = 37 dBie. Carrier tanpa over head dan Reed Solomonf. Free space loss : Uplink = 199.5 dB, Downlink = 196.0 dBg. Rain attenuation : Uplink = 2.30 dB, Dowlink =0.35 dB.h. Frekuensi : Uplink = 6 GHz, Downlink = 4 GHzi. Konstanta Boltzman : -228.6 dBW/K-Hzj. Link margin : tidak diperlukan lagi karena semua loss sudah dihitung.k. Data antena dibawah ini.

Hitung :a. Berapa pointing error untuk uplink dan downlink dari antena ?b. Bandwidth occupied untuk masing-masing carrier, jika bandwidth occupied = 1.20 x Symbol

rate ?c. Eb/No dari masing-masing carrier, jika porsi power satelit dipakai untuk kondisi seimbang

untuk setiap carriernya.d. Jika Eb/No yang diperlukan untuk kedua carrier adalah 6dB, apa komentar saudara ?.

No. Diamterer (m) Tx Gain (dBi) Rx Gain (dBi) G/T (dB/K)1 1,8 39,0 36,0 17,02 2,4 41,5 38,0 19,53 3,0 43,5 40,0 21,54 3,4 44,5 41,5 22,55 3,7 45,0 42,0 23,06 3,8 45,5 42,5 23,57 4,5 47,0 43,5 25,08 5,0 48,0 44,5 26,09 6,0 49,5 46,0 27,5

10 7,6 51,5 48,0 29,511 9,0 53,0 49,5 31,012 10,0 54,0 50,5 32,0

Data Antena

Satellite Communication System Engineering Training Course

ASOSIASI SATELIT INDONESIA (ASSI), Via Renata –Puncak, 25-27 Oktober 2011

JAWABAN - LINK BUDGET & TRANSPONDER MANAGEMENT = 0.052+0.052 = 0.073=20/(FD)Hub Remote3=20/(FD) = 20/(6*6)=0.56PEup = 12()2 = 12(0.07/0.56)2=0.19dB

3=20/(FD) = 20/(6*4)=0.833PEdn = 12()2 = 12(0.07/0.56)2=0.084dB

3=20/(FD) = 20/(6*1.8)=1.85PEup = 12()2 = 12(0.07/1.85)2=0.017dB

3=20/(FD) = 20/(4*1.8)=2.78PEdn = 12()2 = 12(0.07/2.78)2=0.008dB

Outbound InboundBWoccupied=1.2*SR=1.2*(DR/(FEC*m))

BWoccupied=1.2*(512/(0.5*2))=614.4KHz BWoccupied=1.2*(64/(0.5*2))=76.8KHzEIRP saturasi = 40dBw, OBOaggregate=3dBEIRP efektif =40-3=37dBw = 5011.87Watt

%BW=614.4/36000 = 1.71%Kondisi seimbang jadi %BW=%PWR

EIRPoutbound = 1.71%*5011.87=85.54WattAtau 19.32dBw

%BW=76.8/36000 =0.21%

EIRPoutbound = 0.21%*5011.87=10.69WattAtau 10.29dBw

EIRPcxr=19.32dBw, OBOcxr=EIRPsaturasi – EIRPcxr = 20.68dBIBOcxr=OBOcxr+(IBOagg-OBOagg)=22.68dB

EIRPcxr=10.29dBw, OBOcxr=EIRPsaturasi – EIRPcxr = 29.71dBIBOcxr=OBOcxr+(IBOagg-OBOagg)=31.71dB

IBOcxr=SFD-PFDPFD=SFD-IBOcxr=-112.68dBw/m2

IBOcxr=SFD-PFDPFD=SFD-IBOcxr=-121.71dBw/m2

PFD=EIRPes-FSLup-Ltotal+G1C/No = EIRP-FSL-Ltotal+G/T-K(C/No)up=PFD-G1+G/Tsat-K(C/No)up=-112.68-37+2-(-228.6)=80.92dB-Hz

(C/No)up=PFD-G1+G/Tsat-K(C/No)up=-121.78-37+2-(-228.6)=71.89dB-Hz

(C/No)dn=19.32-196-0.35-0.084+17-(-228.6) = 68.49dB-Hz

(C/No)dn=10.29-196-0.35-0.008+27.5-(-228.6) = 70.03dB-Hz

C/Im = 20 dB C/Imo=77.88dB-HzC/Xp = 30 dB C/Xpo=87.88dB-HzC/Iadj = 22 dB C/Iadjo =79.88dB-Hz

C/Im = 20 dB C/Imo=68.85dB-HzC/Xp = 30 dB C/Xpo=78.85dB-HzC/Iadj = 22 dB C/Iadjo =70.85dB-Hz

C/NoTOTAL = [(C/NoUP)-1 + (C/NoDN)-1 +

(C/IoM)-1 +(C/IoADJ)-1 + (C/XoPOLL)-1]-1

C/Nototal=67.49dB-Hz

Eb/No=C/No-10*log(TR), TR=DR/FECEb/No=67.49-10*log(512/0.5)-30 = 7.39dB

C/NoTOTAL = [(C/NoUP)-1 + (C/NoDN)-1 +

(C/IoM)-1 +(C/IoADJ)-1 + (C/XoPOLL)-1]-1

C/Nototal=64.09dB-Hz

Eb/No=C/No-10*log(TR), TR=DR/FECEb/No=64.09-10*log(64/0.5)-30 = 13.02dB

Kesimpulan :Sistem melebih dari yang dipersyaratkan atau sistem bandwidth limited.

Kesimpulan :Sistem melebih dari yang dipersyaratkan atau sistem bandwidth limited.