Hey Marcus, Thank you for replying back! Absolutely, I've posted my flowgraphs on imgur.com now.
Here's the link: http://imgur.com/a/a0KCX Also, for some reason, I think it could be because I'm using the Spectrum analyzer's tracking generator? P.S I've done a couple of changes since my last email: 1) My sample rate is now 10M 2) My filter taps for the channelizer are being calculated as you told me earlier: firdes.low_pass(1.0, samp_rate, samp_rate/(nchan*2.15), samp_rate/(nchan*4.5)) 3) Assuming that the tracking generator is at fault, and everything else in the design is good, it works perfectly fine for a 2M sample rate, but when I try using a higher sampling rate say 10MHz, I get strange results which leads me to believe that there's something wrong in my design, though I just can't put my finger on it. One of the pictures is when I'm asking the channelizer to make a total of 8 channels, and the other one is where I'm asking the channelizer to create 20 channels. (Only 6 of which are being plotted in both cases). Is the way I'm calculating my filter taps at fault here or is it perhaps something else? Best, Ali Date: Tue, 03 Mar 2015 09:42:19 +0100 From: Marcus M?ller <marcus.muel...@ettus.com> To: discuss-gnuradio@gnu.org Subject: Re: [Discuss-gnuradio] Confusion, help please Message-ID: <54f573eb.7000...@ettus.com> Content-Type: text/plain; charset="windows-1252" Hi Ali, that's interesting. Would you mind sharing the flow graph that you use? Greetings, Marcus PS: Although using adblock plus, before I see every other picture on tinypic, I get stuff like casino advertisment, and similar. Could you use any image hoster that doesn't block view on the pictures with advertisement? I found imgur.com to work fairly well. On 03/03/2015 12:27 AM, Ali Riaz wrote: > Hello all, > > I just had a quick question regarding the polyphase channelizer. As a > start, I'm trying to divide an input spectrum into 6 channels of equal > width. My sample rate for now is 5 MHz and the way I'm calculating the > taps as follows: > > firdes.low_pass2(1.0, samp_rate, samp_rate/(nchan*2.15), > samp_rate/(nchan*13.8), attenuation_dB = 10, window = firdes.WIN_HAMMING) > > The channels are being divided equally now, but the first channel > behaves very different from the rest, it becomes super wide for a > moment, and then shrinks back to normal just like the rest of the > channels and this happens repeatedly. I'm honestly stumped as to what > the reason could be, so would really appreciate if anybody can point > me in the right direction or at least clarify why this is happening. > > You can find the images here: http://tinypic.com/a/3e8so/4 > > Thank you, > > Best, > Ali > > > _______________________________________________ > 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
