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

Prateek Dayal wrote: On 4/4/06, *Robert McGwier* <[EMAIL PROTECTED] > wrote: http://www.cds.caltech.edu/~yasi/publications.html Also for frequency offset, what really matters is not the frequency offset in

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

On 4/4/06, Robert McGwier <[EMAIL PROTECTED]> wrote: Jens Elsner wrote:> Achilleas,>> thanks for taking the time. My goal is to implement COFDM in gnuradio,> DAB is a nice start.>> To your points: Time sync is not a problem in OFDM - the guard interval takes care of > that. Nice property. Try p

[Discuss-gnuradio] GNU Radio on MacBook ?

Has anybody tried compiling and running GNU Radio on a new MacBook? Matt ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio

Re: [Discuss-gnuradio] gr-audio-osx ToDo

On Tue, Apr 04, 2006 at 08:47:51PM -0500, Michael Dickens wrote: > I have 3 things to do on gr-audio-osx (enumerated below), but those can > be "ToDo's" or whatever; I would really like to get this code available > for others to try, as feedback on compiling and other issues would make > it inst

[Discuss-gnuradio] gr-audio-osx ToDo

I have 3 things to do on gr-audio-osx (enumerated below), but those can be "ToDo's" or whatever; I would really like to get this code available for others to try, as feedback on compiling and other issues would make it installation robust. The blocks seems to work just fine for everyone who's

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

Jens, I used a complete ad-hoc method for automatic frequency estimation: tracing the minimum ratio of the power of DC over the total power of the remaining channels, averaged over all symbols in a frame. Your estimate seems quite good! I atatch the .m file I have not tried anything with the

Re: [Discuss-gnuradio] Modifications to wfm_rcv_pll.py underway, modifications to gr_pll_carriertracking.cc done

Robert W McGwier wrote: Before, the code (incorrectly in my estimation) returned the complex conjugate of the recovered carrier. This has been "corrected" to be return the recovered carrier. If you need a conjugate from this, accomplish it in your code. Bugs in the locking, squelching m

[Discuss-gnuradio] Modifications to wfm_rcv_pll.py underway, modifications to gr_pll_carriertracking.cc done

Modifications to the FM stereo receiver have been underway for two days. Nothing that changes the way things work inside the FM stereo receiver were included in the tar balls. However a change that could change the way you use gr_pll_carriertracking has been submitted and was in the tar ball.

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

Jens, I looked at your code and I don't know if this makes a difference, but I think the line data = d_resamp(256:1792) should be substituted by data = d_resamp(257:1793) since in an N=2m point FFT the DC is the m+1-st component after fftshift (in our case it is the 1025-th component). I still b

[Discuss-gnuradio] Re: [Flexradio] [softrock40] SDR program for Macintosh

In fairness let me say that this is the fastest thing I have in my lab. Wow the dual G5 is fast. Bob Robert W McGwier wrote: It does. We sent it out to the authorized Mac repair when the PS fan whine snipped. ;-) Bob Barely still capable of hearing in NJ N4HY KD5NWA wrote: Mus

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

Jens Elsner wrote: Achilleas, thanks for taking the time. My goal is to implement COFDM in gnuradio, DAB is a nice start. To your points: Time sync is not a problem in OFDM - the guard interval takes care of that. Nice property. Try playing along with the "start_resamp" value - it will

Re: [Discuss-gnuradio] SDR program for Macintosh

I have to say that I am not going to be a good guy to test for efficiency. This dual G5 is a lightning bolt. I told fftwf-wisdom to run for 1/4 hour. It has already completed the 2^17 and was in the 2^18's before it stopped and moved on to fftw-wisdom. Blistering fast. I look forward to th

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

I guess I was a little bit too quick with my answer... In more detail: > 2) You have done frequency correction manually: did you do this by > looking at the DC subcarrier (no power transmitted here) in the > received signal prior to OFDM demod? > Frequency synchronization in OFDM is very crucial

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

Achilleas, thanks for taking the time. My goal is to implement COFDM in gnuradio, DAB is a nice start. To your points: > I got interested in this discussion and looked at the > standard briefly and at your matlab code. > I have a couple of initial points; I will spend more time sometime this >

Re: [Discuss-gnuradio] SDR program for Macintosh

I have a Dual G4 @ 1.25 GHz running GNURadio w/ my own mods for fast USB and audio. For some reason this model covered under the previous models' noise issue (recall or something like that; none of the G5's are either). They don't call them "wind tunnels" for nothing! There are various mo

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

Jens, I got interested in this discussion and looked at the standard briefly and at your matlab code. I have a couple of initial points; I will spend more time sometime this week on your code: 1) where in the standard it says that this is pi/4 DQPSK ? I only saw that the modulation used is DQP

Re: [Discuss-gnuradio] Packet Radio

Hi Eric, Thank you for the feedback. We will incorporate your comments into a new revision of the document that we should have out soon. Timing and scheduling seem to be the hardest issues, so we'd like to think about them a bit more and then discuss on the list. Cheers, David. On Apr 1,

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

Further more this means that the demodulated symbol (differences!) should always have phase 0, pi/4, 2pi/4, 3pi/4 (plus a *constant* offset of pi/8). But this offset is varying. Am I right? And why should the transmitter introduce a varying offset? The problem is somewhere in the demodulation ch