Hi all, I'm studying effect of phase noise on the BER performances for OFDM QAM Modulation. I found the SNR degradation due to the phase noise: D= 10/ln(10)*(1/60)*(4*pi*Beta*N/R)*SNR where N/R depends n the data rate and the number of OFDM sub-carrier But I don't really understand what is beta and its relationship with the LO curve in function of the frequency, for example -20 dB/dec.... Can someone help me ! thanks
phase noise modelisation
Started by ●January 18, 2008
Reply by ●January 18, 20082008-01-18
dude23 wrote:> Hi all, > > I'm studying effect of phase noise on the BER performances for OFDM QAM > Modulation. I found the SNR degradation due to the phase noise: > D= > 10/ln(10)*(1/60)*(4*pi*Beta*N/R)*SNR > > where N/R depends n the data rate and the number of OFDM sub-carrier > But I don't really understand what is beta and its relationship with the > LO curve in function of the frequency, for example -20 dB/dec.... > > > Can someone help me !Hey, Dude, How did you derive the equation if you don't know what the terms mean? Or by "found", did you mean spotted the equation in a book? In other treatments of phase modulation, BETA is the ratio of modulating frequency to carrier frequency. It seems highly likely that the text containing the equation explains what its terms mean. Jerry -- Engineering is the art of making what you want from things you can get. �����������������������������������������������������������������������
Reply by ●January 25, 20082008-01-25
On Jan 18, 9:44 pm, Jerry Avins <j...@ieee.org> wrote:> dude23 wrote: > > Hi all, > > > I'm studying effect ofphasenoiseon the BER performances for OFDM QAM > > Modulation. I found the SNR degradation due to thephasenoise: > > D= > > 10/ln(10)*(1/60)*(4*pi*Beta*N/R)*SNR > > > where N/R depends n the data rate and the number of OFDM sub-carrier > > But I don't really understand what is beta and its relationship with the > > LO curve in function of the frequency, for example -20 dB/dec.... > > > Can someone help me ! > > Hey, Dude, > > How did you derive the equation if you don't know what the terms mean? > Or by "found", did you mean spotted the equation in a book? In other > treatments ofphasemodulation, BETA is the ratio of modulating > frequency to carrier frequency. It seems highly likely that the text > containing the equation explains what its terms mean. > > Jerry > -- > Engineering is the art of making what you want from things you can get. > �����������������������������������������������������������������������hopefully this will help as they have derived few equations keeping the PSD of phase noise in view http://www.cl.cam.ac.uk/research/dtg/publications/public/vsa23/CSNDSP_vsa23.pdf
Reply by ●January 29, 20082008-01-29
>dude23 wrote: >> Hi all, >> >> I'm studying effect of phase noise on the BER performances for OFDMQAM>> Modulation. I found the SNR degradation due to the phase noise: >> D= >> 10/ln(10)*(1/60)*(4*pi*Beta*N/R)*SNR >> >> where N/R depends n the data rate and the number of OFDM sub-carrier >> But I don't really understand what is beta and its relationship withthe>> LO curve in function of the frequency, for example -20 dB/dec.... >> >> >> Can someone help me ! > >Hey, Dude, > >How did you derive the equation if you don't know what the terms mean? >Or by "found", did you mean spotted the equation in a book? In other >treatments of phase modulation, BETA is the ratio of modulating >frequency to carrier frequency. It seems highly likely that the text >containing the equation explains what its terms mean. > >Jerry >-- >Engineering is the art of making what you want from things you can get. >???????????????????????????????????????????????????????????????????????You are right, I found this expression in this work: http://ieeexplore.ieee.org/iel5/26/8633/00380034.pdf?arnumber=380034 but I don't really understand what is the BETA... Does it correspond to the frequency bandwidth where the phase noise stay constant, before a 1/f^2 slope ?? thanks
