Re: [Discuss-gnuradio] OFDM demodulation problem / example video

[Robert McGwier]

Prateek Dayal wrote:
> On 4/4/06, *Robert McGwier* <address@hidden 
> <mailto:address@hidden>> wrote:
>
>
>
> http://www.cds.caltech.edu/~yasi/publications.html 
> <http://www.cds.caltech.edu/%7Eyasi/publications.html>
>
> Also for frequency offset, what really matters is not the frequency 
> offset in Hz, but the relative frequency offset delta_f/F_s, where F_s 
> is the subcarrier spacing. Please look at
>
> *BER sensitivity of OFDM systems to carrier frequency offset andWiener 
> phase noise*
> Pollet, T.; Van Bladel, M.; Moeneclaey, M.
> Communications, IEEE Transactions on
> Volume 43, Issue 234, Feb/Mar/Apr 1995 Page(s):191 - 193
> Digital Object Identifier   10.1109/26.380034
>
> In general if your relative frequency offset is .01 or less, I think 
> you will not be affected much. But again I am not too sure for DQPSK. 
> Again QAM is more sensitive to these errors than QPSK.
>
> Please correct me if I am wrong somewhere. I am sharing what I have 
> recently learnt about these things ....
>
> Regards
> Prateek Dayal
>  

Thank you very much for the reference.   This was a very nice link to 
Mostofi's work.  The following paper is also pertinent to Jen's thinking 
on the guard interval offset being irrelevant.  It is not of course:

*Y. Mostofi*, D. Cox and A. Bahai, "Effect of Timing Synchronization 
Errors on Pilot-aided Channel Estimation in OFDM: Analysis and 
Solution," /Proceedings of 5^th IEEE International Symposium on Wireless 
Personal Multimedia Communications (WPMC),/ Honolulu, Hawaii, Oct. 2002, 
pp. 1309-1313.

http://www.cds.caltech.edu/~yasi/papers/WPMC02.pdf

Best wishes,
Bob

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