Tutorials - OFDM

[hauris]

Hi, Your tutorials are fantastic and great. You did a really good job, thank you for this work. On the OFDM tutorial Figs 8 and 9, you show a PSK waveform corresponding to bits (1,1,1,-1,-1,-1 & 1,1,-1,1,1,-1 respectively). You show a phase change between the +1s and -1s but why do you have a phase change between the last two -1's (-1-1) in Fig 8 and between the last 2 +1's (1,1,-1) in Fig 9. It seems to me there should not be a phase change there.
Thank you, Jon Hauris

[charan langton]

A few people have noticed this in the OFDM example figures that the BPSK transition do not match with what I am showing. This is beacuse I created the modulated signal in simulation in space that is called "compex envelope". In real modulators, the I channel maps directly to a cosine wave and the Q directly to sine wave. This is what you see in most block diagrams. But when we do simulation, this is done at baseband. And what that means is the information signal maps this way:
I channel = I cos (wt) - Q sin(wt)
Q channel = I cost(wt) + Q sin (wt)
where I stands for bits in the I channel and Q in the Q channel.
So in complex envelope, the mapping is not direct and obvious. So there is no error in the diagrams, its just that the mapping is done not in the way the signals are described as passband.

[muhammadriz]

can anybody provide me good tutorial on ofdm and mimo

[kalidoss]

WHAT IS MEANT BY PAPR IN OFDM? IF ANYBODY KNOW ABOUT PAPA THEN PLEASE INFORM...IT'S VERY URGENT