lte-amc Log formula error

[Arsalan Saeed]

Hello,

Just figured out a small error in the lte-amc module. LINE 320

double s = log2 ( 1 + ( sinr_ /
( (-log (5.0 * m_ber )) /
1.5) ));

int cqi_ = GetCqiFromSpectralEfficiency (s);

NS_LOG_LOGIC (" PRB =" << cqi.size ()
<< ", sinr = " << sinr_ // HERE SINR IS IN NATURAL UNITS
<< " (=" << pow (10.0, sinr_ / 10.0) << " dB)" // TO DISPLAY IN dB
the formula is wrong, resulting in a huge value
<< ", spectral efficiency =" << s
<< ", CQI = " << cqi_ << ", BER = " << m_ber);

cqi.push_back (cqi_);

CORRECTION:
NS_LOG_LOGIC (" PRB =" << cqi.size ()
<< ", sinr = " << sinr_
<< " (=" << (10* (log10 (sinr_)))
<< " dB)" // value in dB= 10 log (value in watt)
<< ", spectral efficiency =" << s
<< ", CQI = " << cqi_ << ", BER =
" << m_ber);


Thanks,
Arsalan

[Vincenzo Rea]

well, using a parentheses less:

<< " (=" << (10* (log10 (sinr_))

right?

[samia dardouri]

I installet ns-3-lte and I excute example lte-amc cc using command.:

  . / waf - run lte-amc

But I can not trace the different curves sinr. is that you can help me please.

I await your reply and sorry for the inconvenience.

[Nicola Baldo]

please do not post the exact same question multiple times
https://groups.google.com/d/msg/ns-3-users/ne5Th_e9hI4/NsjXJwRsxS8J