Re: [Discuss-gnuradio] OFDM Updates

[CHIN-YA HUANG]

Thanks Bob.
However, what I concern is Tom mentioned that the released code has some error 
in the receiver, doesn't it? We did experiment, and really see some problems in 
receiver. That's why I sent e-mail to see if I can get more information about 
the problem since I have no idea how to modify it. 

Chin-Ya 
----- Original Message -----
From: Bob McGwier <address@hidden>
Date: Monday, March 31, 2008 11:54 pm
Subject: Re: [Discuss-gnuradio] OFDM Updates
To: CHIN-YA HUANG <address@hidden>
Cc: address@hidden


> I wonder if you are told several more times that it is already 
> released 
>  in an svn branch if you will finally look to see how to get it?
>  
>  http://gnuradio.org/trac/browser/gnuradio/branches/developers/trondeau/ofdm
>  
>  That took me less than 2 minutes to find.  It will take you less than 
> 
>  two minutes to figure out how to do an svn download on that source.
>  
>  What doesn't work is up to you to fix.  That is the nature of GPL 
>  projects such as this one. 
>  
>  Have fun.
>  
>  Bob
>  
>  
>  
>  CHIN-YA HUANG wrote:
>  > Hi Tom,
>  >
>  > Would you mind release your modified code for me as reference 
> first? Thanks
>  >
>  > Chin-Ya
>  > ----- Original Message -----
>  > From: Tom Rondeau <address@hidden>
>  > Date: Wednesday, March 26, 2008 9:50 am
>  > Subject: Re: [Discuss-gnuradio] OFDM Updates
>  > To: CHIN-YA HUANG <address@hidden>
>  > Cc: address@hidden
>  >
>  >   
>  >> CHIN-YA HUANG wrote:
>  >>     
>  >>> Hello Tom,
>  >>>
>  >>> Based on your information below I know the problem will be 
> receiver. 
>  >>>       
>  >> However, if I want to solve the receiver's problem. Where is the 
>  >> starting point you suggestion? From the gnu-radio core part?
>  >>     
>  >>> Chin-Ya
>  >>>   
>  >>>       
>  >> This problem will be fixed once I get time to merge my current 
> branch, 
>  >>
>  >> which will be in a few days, hopefully.
>  >>
>  >> Tom
>  >>
>  >>
>  >>     
>  >>> From:    Tom Rondeau
>  >>> Subject:         [Discuss-gnuradio] OFDM Updates
>  >>> Date:    Thu, 07 Feb 2008 14:09:58 +0000
>  >>> User-agent:      Thunderbird 2.0.0.9 (Windows/20071031)
>  >>> For anyone working with the OFDM code, my latest check-in to the 
> 
>  >>>       
>  >> trunk fixes some of the main issues of transmitting over the air. 
> 
>  >> Using benchmark_ofdm_rx and benchmark_ofdm_tx on different 
> machines, I 
>  >> am now able to successfully capture most packets with any 
> modulation 
>  >> at the appropriate signal level.
>  >>     
>  >>> I say most packets because there is still an issue involved in 
> the 
>  >>>       
>  >> receiver where the regenerator signal pops up before the peak 
> detector 
>  >> signal resets it and causes a problem in the packet sampler. To 
> see 
>  >> what I mean, run
>  >>     
>  >>> "benchmark_ofdm.py --log"
>  >>>
>  >>> And look at the output of the regen and peak detector blocks:
>  >>> gr_plot_char.py ofdm_sync_pn-regen_b.dat ofdm_sync_pn-peaks_b.dat
>  >>>
>  >>>
>  >>> This will plot a series of 0's with a few 1's, where the peaks 
>  >>>       
>  >> occur. The peak detector sends it out once, and then the 
> regenerator 
>  >> takes over. For every packet, there is one output of the peak 
>  >> detector. If you look, sometimes the peak detector will hit just 
> after 
>  >> a regenerated signal. By this point, it's too late and the 
>  >> ofdm_sampler has already triggered off of the regen signal and 
> ignores 
>  >> the peak.
>  >>     
>  >>> It's a bit of a hassle, but I'll look into it soon. Any help is 
>  >>>       
>  >> appreciated, though :)
>  >>     
>  >>> Tom
>  >>>
>  >>>   
>  >>>       
>  >
>  >
>  > _______________________________________________
>  > Discuss-gnuradio mailing list
>  > address@hidden
>  > http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
>  >
>  >   
>  
>  
>  -- 
>  AMSAT Director and VP Engineering. Member: ARRL, AMSAT-DL,
>  TAPR, Packrats, NJQRP, QRP ARCI, QCWA, FRC. ARRL SDR WG Chair
>  "Debugging is twice as hard as writing the code in the first place.
>  Therefore, if you write the code as cleverly as possible, you are, by
>  definition, not smart enough to debug it." - Brian W. Kernighan 
>  
>