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# Satellite Communications/Bit rate Calculation for DVB-S2 (LDCP)

Question
dear , i would like to ask about calculate the bit rate in satellite in case of DVB-S2 , does it still the same in framing part :

as Ex: if we have a S.R=27500 , FEC = 5/6 , QPSK , and it's in DVB-s not DVB-S2 , normally when we calculate the Bit rate like the following :

Bit rate = S.R * m (mod. factor) * framing * FEC

framing = Viterbi FEC rate = 188/204
FEC (CVr)= Reed solomon FEC Rate (in example case) = 5/6

Bit Rate = 27500 * 2 * 188/204 * 5/6 = 42.23 Mbps

but my question if we used DVB-S2 , LDPC instead of Viterbi/BCH instead of Reed Solomon, does the frame of 188/204 change or stay the same ?

Hi Mr Ammar,
The parameters are all related to the specific schemes and whatever need use in the Bitrate equation should be relavent and not fix some and use the same formula. So the 188/204 if it viterbi specified for framing then it is same for any other standard. LDPC used means corresponding coding rate has to be replacing this figure.
Cheers/GTRao

Satellite Communications

Volunteer

#### TIRUMALA RAO G

##### Expertise

Satellite Communications Applications, Link Calculations, Teleports, Earth Stations,VSAT, Tracking, Mobile Communications, Next Generation Networks.

##### Experience

40 Years. Indian Space Research Organisation, PANAMSAT, Satellite Based VSAT Networks, IP Networks.

Organizations
ISRO, PANAMSAT, Engineering Institution for Higher Education (GVP College of Engineering), Consultancy.

Education/Credentials
Graduate in Electronics and Communication Engineering with Distinction. Guiding scholars for their Doctoral thesis in related areas in Academics.