-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi Yassine,
Please don't be disappointed. Honestly, it's a little unfair: You demand graphical + signal processing performance from an embedded device. People often do this, and I usually like to explain the following: This embedded device has, for the ease of use, a graphical interface. This doesn't make it a substitute for a PC. It is not a weak PC. If you wanted that, you would have bought an old PC and a b100. It is a powerful embedded device. It's intended purpose is of course a demonstration of capabilities (like showing the spectrum of a signal), but foremost it is meant to be used as a remote device doing its signal processing on its own, without a user sitting in front of it. Example? You wouldn't want to install a PC with a screen at every GSM tower. You'd like to have a small box with a network interface that you can access remotely to install your new signal processing routines. It is nice if it has a screen port so a technician might check stuff when he's at the tower. However, that's not the main feature of that box. So basically, you're asking a lot for a device that uses a small wall wart as power supply -- it's not a substitute for a signal processing workstation but a device where you can test and deploy the algorithms you develop on a PC comfortably. Greetings, Marcus On 10.04.2014 12:27, Abouda Yassine wrote: > Thank you all for your responses.I tried to follow your > instructions and I did a lot of experiments to make the fm_receiver > work.I have come to some conclusions,the USRP E110 is really not > that powerful,I frankly say that I am disappointed.According to my > personal experiments the maximum sample rate for the fm_receiver > was 1M and I matched between the different blocks to get a clear > sound at the end.But,when I move the mouse the sound gets > interrupted until I stop moving and when I add an FFT sink it makes > it worse.So, I believe that I reached here the limits of the RAM > ressources I think,and this proves that the USRP E110 is not > powerful or maybe not dedicated for these applications(I am using > the BASIC RX and TX daughterboards).Plz do not hesitate to correct > me if I was misjudging the device because I am a newbie here !! > > Yassine > > > 2014-04-09 14:55 GMT+02:00 Robert McGwier <rwmcgw...@gmail.com>: > >> First 100k is insufficient sample rate from the E110. An FM >> station has 150 kHz total swing (+/- 75 kHz) so the frequency >> range of your E110 complex output is 100 kHz and is therefore >> insufficient for the entire modulation. You then feed the 100k >> sample per second signal into the FM block where you have >> informed it you will be sending 500 kHz (quadrature rate) and >> then with no decimation at all, you send the 500 kHz sample >> rate detected audio to a sound block where you've told it to >> expect 96 kHz audio. >> >> [image: \left [ 0.9 \left [ \frac{A+B}{2} + \frac{A-B}{2}\sin4\pi >> f_pt \right ] + 0.1\sin2\pi f_pt \right ] \times >> 75~\mathrm{kHz}] >> >> >> is the instantaneous frequency of an FM stereo broadcast signal >> where A is the left channel, B is the right channel and fp is the >> pilot tone frequency (19 kHz). >> >> Consider matching sample rates between these blocks as the >> software defined radio equivalent of "impedance matching" between >> analog circuits in one view of it. >> >> Bob >> >> >> >> >> >> On Wed, Apr 9, 2014 at 7:40 AM, Mike Jameson <m...@scanoo.com> >> wrote: >> >>> Here are some pointers for you: >>> >>> - Firstly, your screenshot shows the error message saying that >>> the RX frequency is not valid. I'd recommend using a WBX >>> daughterboard, however the BasicRX should still work with >>> strong FM signals with aliasing if that is what you are using. >>> - The samp_rate is set to 100e3. It should be the master clock >>> rate of the e110 divided by an even number such as 64e6/256 >>> (250e3). - The quadrature rate in the WBFM receive block should >>> be set to samp_rate (250e3) and the Audio decimation should be >>> set to 5. - The audio sink sample rate should be set to >>> samp_rate/audio_decim (250e3/5=50e3). 50e3 is as close to the >>> wanted audio sample rate of 48e3 that you are going to get >>> without using one of the resampler blocks. >>> >>> Mike >>> >>> -- Mike Jameson M0MIK BSc MIET Email: m...@scanoo.com Web: >>> http://scanoo.com >>> >>> >>> ---------- Forwarded message ---------- From: Abouda Yassine >>> <abouda21yass...@gmail.com> Date: Wed, Apr 9, 2014 at 12:09 PM >>> Subject: Re: [Discuss-gnuradio] Problem with getting clear FM >>> signals using the usrp e110 To: Mike Jameson <m...@scanoo.com> >>> >>> >>> hi Mike, >>> >>> thx for offering help.I enclosed both a picture of the fm >>> receiver and the grc file(because i'm using the embedded >>> gnuradio version on the usrpe 110),so it might not open >>> correctly to you.I will be waiting for your answer. >>> >>> >>> 2014-04-09 11:47 GMT+02:00 Mike Jameson <m...@scanoo.com>: >>> >>> Abouda, >>>> >>>> If you attach your GRC file to your reply I'll take a look at >>>> it for you. It sounds like a sample rate mis-match going on >>>> somewhere. >>>> >>>> Mike >>>> >>>> -- Mike Jameson M0MIK BSc MIET Email: m...@scanoo.com Web: >>>> http://scanoo.com >>>> >>>> >>>> On Tue, Apr 8, 2014 at 12:18 PM, Abouda Yassine < >>>> abouda21yass...@gmail.com> wrote: >>>> >>>>> Hello, I followed this tutorial to build a simple FM >>>>> receiver: https://www.youtube.com/watch?v=KWeY2yqwVA0.I am >>>>> using the USRP e110,my problem is I am only getting noise.I >>>>> tried to change blocks and parameters and it worked for me >>>>> when I deleted the rational resampler and made a 100k as a >>>>> sample_rate parameter.I get to hear FM radio stations but >>>>> the quality of the sound is very bad it's like on the SAW >>>>> movie.Any one has a solution on how to improve the sound >>>>> quality!!!!thx >>>>> >>>>> _______________________________________________ >>>>> 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 >>> >>> >> >> >> -- Bob McGwier Co-Owner and Technical Director, Federated >> Wireless, LLC Professor Virginia Tech Senior Member IEEE, >> Facebook: N4HYBob, ARS: N4HY Faculty Advisor Virginia Tech >> Amateur Radio Assn. (K4KDJ) >> > > > > _______________________________________________ Discuss-gnuradio > mailing list Discuss-gnuradio@gnu.org > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQEcBAEBAgAGBQJTRnaVAAoJEBQ6EdjyzlHt4DcH/0EDizevAJ7HAhsXVStiLSe+ 1tTZ9/NxqkSfDJwZNp5AVWiETy5AzRG4DSrSsW1zTpV+QWfz1eHaK/H6vUbeGzxe 8BVonYhOKq8Z83i5jcrc7UyGEexszuiCN4hjRtO7ySQ3bHBa9pteu1nrOgaaOq3I U1ONjRP+gv6/rOyTUgIOgextUgnm4h6UE0VBmMc0b9nXKV5hvnExXirawwOeijFp oUakF6e1qP/43a4s/iIzB1VBN6SUvdBM8X3pLiXIT16sSY+etBXd18k/iopPm5Z5 HT55BnNCrUOxPYhNQGIKNKUY/yR5FPqJI4KbIDGanHtoTlDd2wNjIWzWGD3f8hg= =HbNz -----END PGP SIGNATURE----- _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio