If a forward error correction code is used , the spectral efficiency is reduced from the unencoded modulation efficiency . If a forward error correction code is used , the spectral efficiency is reduced from the uncoded modulation efficiency figure .
Jika kod pembetulan ralat ke hadapan digunakan, kecekapan spektrum dikurangkan daripada kecekapan modulasi yang tidak dikodkan. Jika kod pembetulan ralat ke hadapan digunakan, kecekapan spektrum dikurangkan daripada angka kecekapan modulasi yang tidak dikodkan.