How we can calculate the Q-factor for an Optical M-QAM-OFDM signal in DDO-OFDM or CO-OFDM ?

Q-factor= 20*log10(sqrt(2)*(erfcinv(2*(BER)))); I have searched a lot but unfortunately I only found the equation above that calculate the Q from BER ,but the Q will be infinity when the BER is 0....

15 August 2017 317 3 View