Forums

SNR to EbNo in OFDM scheme

Started by Unknown May 14, 2008
hey all,

I made an ofdm simulation in matlab, I want it to output Ber/EbNo
plot, and I use the awgn function in order to add white noise in the
channel, and as u know the awgn function requires SNR as input, so I
need to convert from Eb/No to SNR.

I know this:
Es/No(dB)=10log10(Tsymb*Fs)+SNR(dB)

now I need to convert the Es/No of the ofdm signal to Eb/No:
Es/No(dB)=Eb/No(dB)+10log10(Nc*log2(M))+10log10(CodeRate)+10log10(Tinf/
(Tinf+Tcp))

where:
M - number of symbols used in the modulation scheme
Nc - number of subcarriers in the ofdm symbol
CodeRate - well..code rate
Tinf - information period in the ofdm system
Tcp - cyclic prefix period in the ofdm system
(Tcp+Tinf = Tsymbol)

I"m not too sure about the last equation, would like confirmation or
correction


thanks
On May 14, 12:28�am, shach...@gmail.com wrote:
> hey all, > > I made an ofdm simulation in matlab, I want it to output Ber/EbNo > plot, and I use the awgn function in order to add white noise in the > channel, and as u know the awgn function requires SNR as input, so I > need to convert from Eb/No to SNR. > > I know this: > Es/No(dB)=10log10(Tsymb*Fs)+SNR(dB) > > now I need to convert the Es/No of the ofdm signal to Eb/No: > Es/No(dB)=Eb/No(dB)+10log10(Nc*log2(M))+10log10(CodeRate)+10log10(Tinf/ > (Tinf+Tcp)) > > where: > M - number of symbols used in the modulation scheme > Nc - number of subcarriers in the ofdm symbol > CodeRate - well..code rate > Tinf - information period in the ofdm system > Tcp - cyclic prefix period in the ofdm system > (Tcp+Tinf = Tsymbol) > > I"m not too sure about the last equation, would like confirmation or > correction > > thanks
SNR = (Eb/No) E[x]^2 Maurice Givens