Re: [Discuss-gnuradio] CMake/SWIG build problems
Hi Rafael, I am preparing a release for the beginning of next week. The release will contain my DRM30 transmitter with various, fully configured flowgraphs that hopefully can be used more or less as-is and especially without deep knowledge of DRM. It's already working, but before releasing my code I want to put together a Readme file explaining how to install/use my software and what the constraints are. When everything is ready to be made public, I will notify the list about it. Currently I am implementing DRM+ support but I cannot say if it will make it into the first release. But as I mentioned before, this project doesn't end for me when GSoC ends. I already wrote to Michael Feilen and asked for a version of his DRM+ receiver software so that I can test my code. We got the same consumer receiver (DR111) here at my institute, but it's a preproduction sample as far as I know and it's quite buggy. Especially bandwidths above 10 kHz (spectrum occupancy 4 and 5) do not work with that receiver and unicode support for text messages is very limited. However, DREAM decodes the signal and so I guess I'm not doing everything wrong =). Best regards, Felix Hi Felix, Do you have something in a ready-to-test state concerning the DRM transmitter? I got a new DRM receiver (DR111) which shows the MER and SNR of the reception. Best regards, Rafael Diniz ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Tuning in uhd_fft.py
Greetings, How are the effects of DC mitigated in GNU radio? For example, if I use the uhd_fft.py to just scan the spectrum, I do not see any DC spike at the centre frequency. When I looked at the code, it has : r = self.u.set_center_freq(target_freq, 0) So I assume, it does not use the advanced tuning feature of UHD. Is this correct? How, in this case is there no DC spike seen at the centre frequency? I am trying to code a scanning system that goes through the whole frequency band of my RFX2400 dboard and at each center frequency, I grab a packet from the air and apply an FFT to check for possible interferers etc. But I am ending up with a spike at every centre frequency iteration. I have used the two stage advanced tuning to try and push the DC leakage out of my band of interest but I see no difference. I still get that single spike. (I am using the UHD library and not GNU Radio) Best Regards, Sanat ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Tuning in uhd_fft.py
On 08/17/2012 05:09 AM, Sanat Gulvadi wrote: Greetings, How are the effects of DC mitigated in GNU radio? For example, if I use the uhd_fft.py to just scan the spectrum, I do not see any DC spike at the centre frequency. When I looked at the code, it has : r = self.u.set_center_freq(target_freq, 0) So I assume, it does not use the advanced tuning feature of UHD. Is this correct? How, in this case is there no DC spike seen at the centre frequency? I am trying to code a scanning system that goes through the whole frequency band of my RFX2400 dboard and at each center frequency, I grab a packet from the air and apply an FFT to check for possible interferers etc. But I am ending up with a spike at every centre frequency iteration. I have used the two stage advanced tuning to try and push the DC leakage out of my band of interest but I see no difference. I still get that single spike. (I am using the UHD library and not GNU Radio) There is a DC removal in the USRP, but it needs some time to integrate. Perhaps in the gnuradio case, you are looking at an FFT that has had some time to integrate at the new frequency. But in your finite acquisition case, there is no time. -josh ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Question on FFT
On 08/17/2012 11:45 AM, Sam mite wrote: Hi All, I wanted to work on FFT using gnuradio. I have a question. Why there is only one frequency shown in plot ? why negative frequency is not being displayed ? I have attached picture of GRC implementation and FFT plot as well. So, the blue color means complex floats. The signal source is not producing sin(t), its producing e^jwt -josh Best Regards, Sam ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Question on FFT
On 17 Aug 2012 14:45, Sam mite wrote: Hi All, I wanted to work on FFT using gnuradio. I have a question. Why there is only one frequency shown in plot ? why negative frequency is not being displayed ? I have attached picture of GRC implementation and FFT plot as well. Best Regards, Sam Because there's no negative frequency component in your sample stream. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Last day for early registration!
Hi everyone, Just a reminder that today is the last day to sign up for GRCon 2012 at the early registration rate. The rate will increase midnight EDT. And remember, tell your friends! Tom ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] fine offset for XCVR2450
Hi Everyone, Does the XCVR2450 (when acting as a transceiver) exhibit the same frequency offset for both its RX and TX operations in OFDM? I know fine offset value can change depending on various factors, and to alleviate that problem, I'm using an external clock (without the GPS) connected to my N200. When I use the XCVR only as a receiver, I can see that the fine offset now is much more stable (as compared to when the external clock isn't used) for several packets. However, when it acts as a transceiver, it seems to me that the fine offset can fluctuate quite a bit between the RX and the TX ends. I don't know if it helps but I've also tuned the UHD using ( http://files.ettus.com/uhd_docs/manual/html/general.html#tuning-notes). I've used the same setting for both the rx_freq and tx_freq. Thanks, Apurv ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
