# Transport block size LTE calculation in the Vienna Simulator? [CLOSED]

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I would like to understand the relation between the TB size calculation in the TS36.213 document and in the Vienna Simulator https://www.nt.tuwien.ac.at/research/mobile-communications/vienna-lte-a-simulators . I’m going to make an example so maybe you can help me to see this relation:

Method 1 (from the TS36.213)

Calculation Procedure for downlink(PDSCH) is as follows :
i) refer to TS36.213 Table 7.1.7.1-1
ii) get I_TBS for using MCS value (Let’s assume MCS is 1. in this case, I_TBS is 1 )
iii) refer to TS36.213 Table7.1.7.2.1
iv) go to column header indicating the number of RB (Let’s assume that RB is 50)
v) go to row header ‘1’ which is I_TBS
vi) we would get 1800 (if the number of RB is 50 and I_TBS is 9)
vii) (This is Transport Block Size per 1 ms for one Antenna)

And this is method 2 (in the simulator):
i) This is the formula:
TB_size_bits = max(8*round(1/8*(the_RB_grid.sym_per_RB_nosync .* num_assigned_RB .* modulation_order .* coding_rate * 2))-24,0);
ii) if the_RB_grid.sym_per_RB_nosyn= 80
iii) num_assigned_RB=50
iv) modulation_order = 2
v) coding_rate=0.0762
vi) That gives TB_size_bits = 11952 bits

Do you know how I can go from one method to another or if there is any relation?

closed with the note: found the answer
posted Feb 25, 2016
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What is the source of the formula that you mention?
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