IMTAphy

about getSuitableDownlinkMCSindexForEffSINR

Asked by ckjao

Hello,
I notice that in the function,
ModulationAndCodingSchemes::getSuitableDownlinkMCSindexForEffSINR,
the "conventionalMCS" will always equal to minMCS=0. That is strange and does not make sense.

Does the "conventionalMCS" mean the maximum MCS that makes the BLER<0.1 ?
If it is true, shall we rewrite the code as?

for (mcs = maxMCS; mcs >= minMCS; mcs--)
{
    ....................

    if ((bler <= 0.1) && (mcs > conventionalMCS))
            conventionalMCS = mcs;
}

Best regards,
ckjao

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Jan
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Best Jan (jan-ellenbeck) said : 		#1

Hi,

I agree, that piece of code should have been cleaned up...

Basically, the idea is to pick the MCS that delivers the best expected throughput based on the expected BLER and the corresponding transport block size. The initial (i.e., the "conventional") implementation was probably to pick to highest MCS for which BLER < 10%. I think that the "conventionalMCS" variable would indeed hold this value and that it would not necessarily be 0 all the time. Note, however, that "conventionalMCS" is never used because the printout, for which it was computed, is commented out.

Best regards
Jan

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ckjao (jaochinkuo) said : 		#2

Thanks Jan, that solved my question.