DVB-S,DVB-S2 and DVB-S2X Downlink budget calculator

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Satellite&Transponder


Double click on satellite to open "single satellite view" with lots of details

 
Satellite Position

equals West

Degrees
Uplink Carrier to noise (C+N/N)

dB
Satellite txp. Carrier to co-channel interference (C/Ico)

dB
Satellite txp. Carrier to intermodulation (C/Iim)

dBW/4kHz
Location

 
Latitude

Degminsec

 
Longitude

Degminsec

 
Azimuth Degrees
Elevation Degrees
Slant Range

km
Satellite delay (Up+Downlink)

ms
Antenna Diameter

Meter
Antenna Efficiency

%
Antenna Gain

dBi
Antenna Noise Temperature

Kelvin
LNB Noise Figure

dB
LNB Input VSWR

1:

 
Waveguide loss

dB
Polarizer loss

dB
System Noise Temperature

Kelvin
G/Tsys

dB/Kelvin
Rx Frequency

MHz
IF frequency (Universal LNB swo 11700MHz)

MHz
Downlink EIRP (from footprint)

dBW
Free Space Path Loss

dB
Atmospheric loss

dB
Symbolrate

kBaud
FEC

 
DVB-S2 Pilot

 
Information Capacity
(Netto Bitrate)

kBit/s
Theoretical Information Capacity(Shannon limit)

kBbit/s
Coding efficiency based on Shannon limit

%
Modulator Rolloff

 
Modulator/demodulator
implementation margin(DVB-S)

dB

 
Occupied Bandwidth

MHz
LNB/Feedhorn cross polarisation isolation

dB
Isolation between LNB outputs

dB
Multiswitch Isolation between inputs

dB
Multiswitch Isolation between outputs

dB
Allocated Bandwidth

MHz
C/No

dBHz
C/N Occupied Bandwidth(isolation not accounted for)

dB
C/N Degradation

dB
C/N Occupied Bandwidth

dB
Eb/No Nettobitrate ( TS payload bitrate)

dB
C+N/N

dB
C/N

dB
Eb/No datarate

dB
Eb/No Transmission rate

dB
Eb/No Margin

dB ( +6dB is recommended)

Rain Fade Calculations

Attenuation model ITU-R-REC-P.838 ITU Rain Zones based on R-REC-P.837
Measured C/N margin dB
LNB noise temperature K
Ground Noise temperature K
Sky Noise temperature K
Rain noise temperature K
Ambient noise temperature K
Antenna feed/wg loss dB
Margin rain attenuation dB
Margin G/T degradation dB
Calculated rain height km
D rain (pathlength trough rain) km
Hight above ocean km
Polarisation
ITU Rain zone Find your ITU Rain Zone here
Frequency GHz
Alfa (for rain attenuation calculation)
K (for rain attenuation calculation)
Max rain path attenuation dB/km
Max rainrate mm/hour
Rain attenuation for 99.9% availability dB
Availability %
Estimated rainfade outage in a year

 

Receiver Input Level Calculation

Power reaching Antenna dBW
Power flux density at earthstation dBW/M^2
LNB input power dBW
LNB Gain dB
LNB output power dBmW
Cable loss dB/100 meters ( Click on the table below)
Coax cable length m
Coax cable loss dB
Splitter1 number of outputs
Splitter2 number of outputs (cascaded from splitter1)
Total loss splitters dB
Additional user defined loss dB
Demodulator maximum power dBmW
Demodulator minimum power dBmW
Demodulator Input Power dBmW
Agilent E4402B S/A Measured Input Noise Density dBm/Hz
Demodulator Input Noise Density dBm/Hz
Demodulator Input Level 75ohm dBuV@75ohm RMS
Demodulator Input Level 50ohm dBuV@50ohm RMS

White cells are outputvalues

Most receivers are specified to work between -30dBmW to -60dBmW.

Be aware that increasing the level won't help if the received carrier to noise is too low ( i.e. antenna too small).

 

Cable loss for some common cables - Click on the value you want to use !

Cable type 100MHz 200MHz 500MHz 900MHz 1450MHz 1750MHz 2050MHz
RG179 32.0dB 47.0dB 65.0dB 100.0dB 125.0dB 141.0dB 158.0dB
RG59/U 8.5dB 13.1dB 21.3dB 29.5dB 39.0dB 44.6dB 50.2dB
RG6/U 6.9dB 10.2dB 16.4dB 22.6dB 29.8dB 34.1dB 38.4dB
RG11/U 4.9dB 7.2dB 12.1dB 17.1dB 22.6dB 25.9dB 29.2dB

Threshold Eb/No as specified by ETS 300 421

The C/Iim and C/Ico values for Intelsat transponders can be found in IESS 410e table 1a page17 and table 2b page21. 
The default C/Iim and C/Ico values are typical for Intelsat VIIA series Ku-spot beam in multicarrier mode. 
For satellites with one carrier pr. transponder the typical values could be C/Iim =-30dBW/4kHz and C/Ico =40dBW/4kHz.

For Intelsat VII series satellites Ku-band the values are C/Iim =-16dBW/4kHz and C/Ico =20.5dBW/4kHz. 
This are worst case values for multicarrier transponders.

Use the calculated values as a indication only and be sure there is a recommended 6dB downlink margin.

Threshold Eb/No as specified by ETS 300 421.

FEC

Eb/No[dB] Calculated[dB]

1/2

4.5

2/3

5.0

3/4

5.5

5/6

6.0

7/8

6.4

1

9.0

DVB-S threshold values includes a 0.8dB modem implementation margin. It is likely that the the thresholds can be up to 0.8dB better than specified for DVB-S.
Table below shows all theoretical C/N(SNR) thresholds for DVB-S and DVB-S2


2002-2007 Jens T. Satre